Topics

[PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP (Envelope) Digest interface


Zurcher, Christopher J
 

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257 ++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128 ++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128 ++++++++++
9 files changed, 647 insertions(+)

diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//=====================================================================================
+// EVP (Envelope) Primitive
+//=====================================================================================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest value into
+ the specified memory. After this function has been called, the EVP context cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//=====================================================================================
// Symmetric Cryptography Primitive
//=====================================================================================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
+ if (Digest == NULL) {
+ return NULL;
+ }
+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest value into
+ the specified memory. After this function has been called, the EVP context cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }
+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
--
2.28.0.windows.1


Laszlo Ersek
 

Hello Christopher,

On 09/16/20 02:59, Zurcher, Christopher J wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257 ++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128 ++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128 ++++++++++
9 files changed, 647 insertions(+)
I agree that "CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c"
is necessary. (If I understand correctly, that file was missing from
your v2 posting.)

But "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c" seems
superfluous. This file is never referenced in the INF files.

The point of this file would be to allow *some* of the Base / Pei /
Runtime / Smm instances to "stub out" the EVP MD functions (i.e. provide
only stub implementations). But this isn't what's happening -- all of
the Base / Pei / Runtime / Smm instances are getting the real deal
("CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c").

(1) So I think "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c"
should be dropped. Only the Null instance of the library needs null
versions of the new functions. The Base / Pei / Runtime / Smm instances
don't.


diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//=====================================================================================
+// EVP (Envelope) Primitive
+//=====================================================================================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest value into
+ the specified memory. After this function has been called, the EVP context cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest value.
(2) Please extend the comment on Digest with the following:

The caller is responsible for providing enough storage for the digest
algorithm selected with EvpMdInit(). Providing EVP_MAX_MD_SIZE bytes
will suffice for storing the digest regardless of the algorithm chosen
in EvpMdInit().

(EVP_MAX_MD_SIZE is a public OpenSSL macro and I think we should openly
advertise it to consumers in edk2.)

+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).

+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//=====================================================================================
// Symmetric Cryptography Primitive
//=====================================================================================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
I think this may not compile with gcc (and correctly so). The pointer
returned by EVP_get_digestbyname() is const-qualified, but with the
assignment, we're throwing away the const-ness.

(4) Please const-qualify the "Digest" local pointer.

+ if (Digest == NULL) {
+ return NULL;
+ }
(5) This is a memory leak I believe; "EvpMdContext" is leaked.

For keeping the control flow simple, consider moving
EVP_get_digestbyname() above EVP_MD_CTX_new().

+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
(6) Can you please confirm that the caller is supposed to initialize
"NewEvpMdContext" with EvpMdInit() first, before calling EvpMdDuplicate()?

+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest value into
+ the specified memory. After this function has been called, the EVP context cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }

(7) I suggest dropping the "Length" local variable. EVP_DigestFinal_ex()
deals fine with the third parameter being NULL, according to the docs
(and the code).


+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
(8) Style: please write (!Result).


+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
Thanks,
Laszlo


Yao, Jiewen
 

Hi Laszlo
I disagree to put OPTIONAL for DigestValue, just because NULL is checked.
If we need follow this, then we need add OPTIONAL to almost all pointer, which is unnecessary.

+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).




-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 7:07 PM
To: devel@edk2.groups.io; Zurcher, Christopher J
<christopher.j.zurcher@...>
Cc: Yao, Jiewen <jiewen.yao@...>; Wang, Jian J <jian.j.wang@...>;
Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hello Christopher,

On 09/16/20 02:59, Zurcher, Christopher J wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257
++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128 ++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128 ++++++++++
9 files changed, 647 insertions(+)
I agree that "CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c"
is necessary. (If I understand correctly, that file was missing from
your v2 posting.)

But "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c" seems
superfluous. This file is never referenced in the INF files.

The point of this file would be to allow *some* of the Base / Pei /
Runtime / Smm instances to "stub out" the EVP MD functions (i.e. provide
only stub implementations). But this isn't what's happening -- all of
the Base / Pei / Runtime / Smm instances are getting the real deal
("CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c").

(1) So I think "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c"
should be dropped. Only the Null instance of the library needs null
versions of the new functions. The Base / Pei / Runtime / Smm instances
don't.


diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h
b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//==============================================================
=======================
+// EVP (Envelope) Primitive
+//==============================================================
=======================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest
value.

(2) Please extend the comment on Digest with the following:

The caller is responsible for providing enough storage for the digest
algorithm selected with EvpMdInit(). Providing EVP_MAX_MD_SIZE bytes
will suffice for storing the digest regardless of the algorithm chosen
in EvpMdInit().

(EVP_MAX_MD_SIZE is a public OpenSSL macro and I think we should openly
advertise it to consumers in edk2.)

+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).

+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//===============================================================
======================
// Symmetric Cryptography Primitive
//===============================================================
======================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
I think this may not compile with gcc (and correctly so). The pointer
returned by EVP_get_digestbyname() is const-qualified, but with the
assignment, we're throwing away the const-ness.

(4) Please const-qualify the "Digest" local pointer.

+ if (Digest == NULL) {
+ return NULL;
+ }
(5) This is a memory leak I believe; "EvpMdContext" is leaked.

For keeping the control flow simple, consider moving
EVP_get_digestbyname() above EVP_MD_CTX_new().

+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
(6) Can you please confirm that the caller is supposed to initialize
"NewEvpMdContext" with EvpMdInit() first, before calling EvpMdDuplicate()?

+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in
OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest
value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }

(7) I suggest dropping the "Length" local variable. EVP_DigestFinal_ex()
deals fine with the third parameter being NULL, according to the docs
(and the code).


+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
(8) Style: please write (!Result).


+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
Thanks,
Laszlo


Yao, Jiewen
 

I overlooked the behavior that NULL DigestValue will take side effect to free Context.

Hi Christopher
May I understand why we need free the context?
This does not align with other existing HASH or HMAC functions.

Thank you
Yao Jiewen

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Yao, Jiewen
Sent: Wednesday, September 16, 2020 7:45 PM
To: Laszlo Ersek <lersek@...>; devel@edk2.groups.io; Zurcher,
Christopher J <christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hi Laszlo
I disagree to put OPTIONAL for DigestValue, just because NULL is checked.
If we need follow this, then we need add OPTIONAL to almost all pointer, which
is unnecessary.

+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).




-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 7:07 PM
To: devel@edk2.groups.io; Zurcher, Christopher J
<christopher.j.zurcher@...>
Cc: Yao, Jiewen <jiewen.yao@...>; Wang, Jian J
<jian.j.wang@...>;
Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hello Christopher,

On 09/16/20 02:59, Zurcher, Christopher J wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257
++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128 ++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128
++++++++++
9 files changed, 647 insertions(+)
I agree that "CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c"
is necessary. (If I understand correctly, that file was missing from
your v2 posting.)

But "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c" seems
superfluous. This file is never referenced in the INF files.

The point of this file would be to allow *some* of the Base / Pei /
Runtime / Smm instances to "stub out" the EVP MD functions (i.e. provide
only stub implementations). But this isn't what's happening -- all of
the Base / Pei / Runtime / Smm instances are getting the real deal
("CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c").

(1) So I think "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c"
should be dropped. Only the Null instance of the library needs null
versions of the new functions. The Base / Pei / Runtime / Smm instances
don't.


diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h
b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//==============================================================
=======================
+// EVP (Envelope) Primitive
+//==============================================================
=======================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.

(2) Please extend the comment on Digest with the following:

The caller is responsible for providing enough storage for the digest
algorithm selected with EvpMdInit(). Providing EVP_MAX_MD_SIZE bytes
will suffice for storing the digest regardless of the algorithm chosen
in EvpMdInit().

(EVP_MAX_MD_SIZE is a public OpenSSL macro and I think we should openly
advertise it to consumers in edk2.)

+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).

+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//===============================================================
======================
// Symmetric Cryptography Primitive
//===============================================================
======================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
I think this may not compile with gcc (and correctly so). The pointer
returned by EVP_get_digestbyname() is const-qualified, but with the
assignment, we're throwing away the const-ness.

(4) Please const-qualify the "Digest" local pointer.

+ if (Digest == NULL) {
+ return NULL;
+ }
(5) This is a memory leak I believe; "EvpMdContext" is leaked.

For keeping the control flow simple, consider moving
EVP_get_digestbyname() above EVP_MD_CTX_new().

+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
(6) Can you please confirm that the caller is supposed to initialize
"NewEvpMdContext" with EvpMdInit() first, before calling EvpMdDuplicate()?

+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in
OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }

(7) I suggest dropping the "Length" local variable. EVP_DigestFinal_ex()
deals fine with the third parameter being NULL, according to the docs
(and the code).


+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
(8) Style: please write (!Result).


+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
Thanks,
Laszlo


Laszlo Ersek
 

On 09/16/20 14:07, Yao, Jiewen wrote:
I overlooked the behavior that NULL DigestValue will take side effect to free Context.

Hi Christopher
May I understand why we need free the context?
This does not align with other existing HASH or HMAC functions.
I requested that.

It makes no sense to keep a finalized context.

In other words, it makes no sense to separate finalization from freeing.
A context that has been finalized is unusable for anything except freeing.

Thanks
Laszlo


Thank you
Yao Jiewen

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Yao, Jiewen
Sent: Wednesday, September 16, 2020 7:45 PM
To: Laszlo Ersek <lersek@...>; devel@edk2.groups.io; Zurcher,
Christopher J <christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hi Laszlo
I disagree to put OPTIONAL for DigestValue, just because NULL is checked.
If we need follow this, then we need add OPTIONAL to almost all pointer, which
is unnecessary.

+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).




-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 7:07 PM
To: devel@edk2.groups.io; Zurcher, Christopher J
<christopher.j.zurcher@...>
Cc: Yao, Jiewen <jiewen.yao@...>; Wang, Jian J
<jian.j.wang@...>;
Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hello Christopher,

On 09/16/20 02:59, Zurcher, Christopher J wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257
++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128 ++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128
++++++++++
9 files changed, 647 insertions(+)
I agree that "CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c"
is necessary. (If I understand correctly, that file was missing from
your v2 posting.)

But "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c" seems
superfluous. This file is never referenced in the INF files.

The point of this file would be to allow *some* of the Base / Pei /
Runtime / Smm instances to "stub out" the EVP MD functions (i.e. provide
only stub implementations). But this isn't what's happening -- all of
the Base / Pei / Runtime / Smm instances are getting the real deal
("CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c").

(1) So I think "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c"
should be dropped. Only the Null instance of the library needs null
versions of the new functions. The Base / Pei / Runtime / Smm instances
don't.


diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h
b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//==============================================================
=======================
+// EVP (Envelope) Primitive
+//==============================================================
=======================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.

(2) Please extend the comment on Digest with the following:

The caller is responsible for providing enough storage for the digest
algorithm selected with EvpMdInit(). Providing EVP_MAX_MD_SIZE bytes
will suffice for storing the digest regardless of the algorithm chosen
in EvpMdInit().

(EVP_MAX_MD_SIZE is a public OpenSSL macro and I think we should openly
advertise it to consumers in edk2.)

+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).

+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//===============================================================
======================
// Symmetric Cryptography Primitive
//===============================================================
======================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
I think this may not compile with gcc (and correctly so). The pointer
returned by EVP_get_digestbyname() is const-qualified, but with the
assignment, we're throwing away the const-ness.

(4) Please const-qualify the "Digest" local pointer.

+ if (Digest == NULL) {
+ return NULL;
+ }
(5) This is a memory leak I believe; "EvpMdContext" is leaked.

For keeping the control flow simple, consider moving
EVP_get_digestbyname() above EVP_MD_CTX_new().

+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
(6) Can you please confirm that the caller is supposed to initialize
"NewEvpMdContext" with EvpMdInit() first, before calling EvpMdDuplicate()?

+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in
OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }

(7) I suggest dropping the "Length" local variable. EVP_DigestFinal_ex()
deals fine with the third parameter being NULL, according to the docs
(and the code).


+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
(8) Style: please write (!Result).


+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
Thanks,
Laszlo


Yao, Jiewen
 

I try to understand what is the use case to EvpMdFinal without DigestValue and only Free the EvpMdContext.

A normal usage will be:
1) EvpMdHashAll (Digest) - get digest.
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest) - get digest

Why we need support the case to use EvpMdFinal (NULL) in the end to free context?


Thank you
Yao Jiewen

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Laszlo Ersek
Sent: Wednesday, September 16, 2020 8:40 PM
To: Yao, Jiewen <jiewen.yao@...>; devel@edk2.groups.io; Zurcher,
Christopher J <christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

On 09/16/20 14:07, Yao, Jiewen wrote:
I overlooked the behavior that NULL DigestValue will take side effect to free
Context.

Hi Christopher
May I understand why we need free the context?
This does not align with other existing HASH or HMAC functions.
I requested that.

It makes no sense to keep a finalized context.

In other words, it makes no sense to separate finalization from freeing.
A context that has been finalized is unusable for anything except freeing.

Thanks
Laszlo


Thank you
Yao Jiewen

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Yao,
Jiewen
Sent: Wednesday, September 16, 2020 7:45 PM
To: Laszlo Ersek <lersek@...>; devel@edk2.groups.io; Zurcher,
Christopher J <christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX
<xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hi Laszlo
I disagree to put OPTIONAL for DigestValue, just because NULL is checked.
If we need follow this, then we need add OPTIONAL to almost all pointer,
which
is unnecessary.

+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).




-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 7:07 PM
To: devel@edk2.groups.io; Zurcher, Christopher J
<christopher.j.zurcher@...>
Cc: Yao, Jiewen <jiewen.yao@...>; Wang, Jian J
<jian.j.wang@...>;
Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hello Christopher,

On 09/16/20 02:59, Zurcher, Christopher J wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257
++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128
++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128
++++++++++
9 files changed, 647 insertions(+)
I agree that "CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c"
is necessary. (If I understand correctly, that file was missing from
your v2 posting.)

But "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c" seems
superfluous. This file is never referenced in the INF files.

The point of this file would be to allow *some* of the Base / Pei /
Runtime / Smm instances to "stub out" the EVP MD functions (i.e. provide
only stub implementations). But this isn't what's happening -- all of
the Base / Pei / Runtime / Smm instances are getting the real deal
("CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c").

(1) So I think "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c"
should be dropped. Only the Null instance of the library needs null
versions of the new functions. The Base / Pei / Runtime / Smm instances
don't.


diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h
b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//==============================================================
=======================
+// EVP (Envelope) Primitive
+//==============================================================
=======================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated
and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(),
and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP
context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.

(2) Please extend the comment on Digest with the following:

The caller is responsible for providing enough storage for the digest
algorithm selected with EvpMdInit(). Providing EVP_MAX_MD_SIZE bytes
will suffice for storing the digest regardless of the algorithm chosen
in EvpMdInit().

(EVP_MAX_MD_SIZE is a public OpenSSL macro and I think we should openly
advertise it to consumers in edk2.)

+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).

+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//===============================================================
======================
// Symmetric Cryptography Primitive
//===============================================================
======================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated
and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
I think this may not compile with gcc (and correctly so). The pointer
returned by EVP_get_digestbyname() is const-qualified, but with the
assignment, we're throwing away the const-ness.

(4) Please const-qualify the "Digest" local pointer.

+ if (Digest == NULL) {
+ return NULL;
+ }
(5) This is a memory leak I believe; "EvpMdContext" is leaked.

For keeping the control flow simple, consider moving
EVP_get_digestbyname() above EVP_MD_CTX_new().

+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
(6) Can you please confirm that the caller is supposed to initialize
"NewEvpMdContext" with EvpMdInit() first, before calling EvpMdDuplicate()?

+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(),
and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in
OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP
context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }

(7) I suggest dropping the "Length" local variable. EVP_DigestFinal_ex()
deals fine with the third parameter being NULL, according to the docs
(and the code).


+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
(8) Style: please write (!Result).


+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
Thanks,
Laszlo



Laszlo Ersek
 

On 09/16/20 14:39, Laszlo Ersek wrote:
On 09/16/20 14:07, Yao, Jiewen wrote:
I overlooked the behavior that NULL DigestValue will take side effect to free Context.

Hi Christopher
May I understand why we need free the context?
This does not align with other existing HASH or HMAC functions.
I requested that.

It makes no sense to keep a finalized context.

In other words, it makes no sense to separate finalization from freeing.
A context that has been finalized is unusable for anything except freeing.
To clarify my point about (DigestValue==NULL): the freeing of the
context is not tied to (DigestValue==NULL). When finalizing the context,
the context should *always* be freed. (DigestValue==NULL) only decides
whether we *only* free the context, or we store the computed digest *in
addition to* freeing the context.

So the unconditional part of the finalization is the freeing; the
conditional part is the storing of the digest.

Thanks
Laszlo


Laszlo Ersek
 

On 09/16/20 13:44, Yao, Jiewen wrote:
Hi Laszlo
I disagree to put OPTIONAL for DigestValue, just because NULL is checked.
If we need follow this, then we need add OPTIONAL to almost all pointer, which is unnecessary.
I'm not suggesting OPTIONAL *only* because NULL is checked. I'm
suggesting OPTIONAL because there is a specific use case related to
that. Please see the comments on the function:

"If DigestValue is NULL, free the Context then return FALSE."

But, anyway, I don't insist. It's not a huge deal. Feel free to ignore
my comment regarding OPTIONAL.

Thanks
Laszlo



+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).




-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 7:07 PM
To: devel@edk2.groups.io; Zurcher, Christopher J
<christopher.j.zurcher@...>
Cc: Yao, Jiewen <jiewen.yao@...>; Wang, Jian J <jian.j.wang@...>;
Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hello Christopher,

On 09/16/20 02:59, Zurcher, Christopher J wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257
++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128 ++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128 ++++++++++
9 files changed, 647 insertions(+)
I agree that "CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c"
is necessary. (If I understand correctly, that file was missing from
your v2 posting.)

But "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c" seems
superfluous. This file is never referenced in the INF files.

The point of this file would be to allow *some* of the Base / Pei /
Runtime / Smm instances to "stub out" the EVP MD functions (i.e. provide
only stub implementations). But this isn't what's happening -- all of
the Base / Pei / Runtime / Smm instances are getting the real deal
("CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c").

(1) So I think "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c"
should be dropped. Only the Null instance of the library needs null
versions of the new functions. The Base / Pei / Runtime / Smm instances
don't.


diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h
b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//==============================================================
=======================
+// EVP (Envelope) Primitive
+//==============================================================
=======================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest
value.

(2) Please extend the comment on Digest with the following:

The caller is responsible for providing enough storage for the digest
algorithm selected with EvpMdInit(). Providing EVP_MAX_MD_SIZE bytes
will suffice for storing the digest regardless of the algorithm chosen
in EvpMdInit().

(EVP_MAX_MD_SIZE is a public OpenSSL macro and I think we should openly
advertise it to consumers in edk2.)

+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).

+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//===============================================================
======================
// Symmetric Cryptography Primitive
//===============================================================
======================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
I think this may not compile with gcc (and correctly so). The pointer
returned by EVP_get_digestbyname() is const-qualified, but with the
assignment, we're throwing away the const-ness.

(4) Please const-qualify the "Digest" local pointer.

+ if (Digest == NULL) {
+ return NULL;
+ }
(5) This is a memory leak I believe; "EvpMdContext" is leaked.

For keeping the control flow simple, consider moving
EVP_get_digestbyname() above EVP_MD_CTX_new().

+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
(6) Can you please confirm that the caller is supposed to initialize
"NewEvpMdContext" with EvpMdInit() first, before calling EvpMdDuplicate()?

+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(), and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in
OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest
value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }

(7) I suggest dropping the "Length" local variable. EVP_DigestFinal_ex()
deals fine with the third parameter being NULL, according to the docs
(and the code).


+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
(8) Style: please write (!Result).


+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
Thanks,
Laszlo


Yao, Jiewen
 

Thank you Laszlo.
You forced me to read the code again and more carefully. :-)

I believe I understand why you use NULL to free the context now - to support error path.

First, I did have some new thought for EVP API. Let’s consider 3 cases, 1) Hash all data one time, 2) Hash update data multiple times, 3) Error during update.

A. In current design, the API sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR, EvpMdFinal (NULL)

B. We can auto free context in EvpMdUpdate in error path - the API sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR

C: We can use New/Free style - similar to HMAC
1) EvpMdHashAll (Digest)
2) EvpMdNew, EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest), EvpMdFree
3) EvpMdNew, EvpMdInit, EvpMdUpdate->ERROR, EvpMdFree

I checked below APIs:
1) openssl (EVP_MD_CTX_new, EVP_DigestInit_ex, EVP_DigestUpdate, EVP_DigestFinal_ex, EVP_MD_CTX_free)
2) mbedtls (mbedtls_sha256_init, mbedtls_sha256_starts_ret, mbedtls_sha256_update_ret, mbedtls_sha256_finish_ret, mbedtls_sha256_free)
3) BaseCryptoLib HMAC (HmacSha256New, HmacSha256SetKey, HmacSha256Update, HmacSha256Final, HmacSha256Free)

All APIs include free function to free the context, I don’t think it is a bad idea to have EvpMdFree() API.
I would like to propose option - C.


Second, I believe EVP is just something in openssl. It does not mean that we *have to* design API to follow openssl.
After rethink the size impact, I do have concern to merge all Hash implementation together in one function.
It might means nothing if the crypto library is based upon openssl.
But if the cryptolib implementation is based upon other crypto, such as Intel IPP (https://github.com/slimbootloader/slimbootloader/tree/master/BootloaderCommonPkg/Library/IppCryptoLib) or mbedTls (https://github.com/jyao1/edk2/tree/DeviceSecurity/CryptoMbedTlsPkg), then we can NOT get size benefit by separating the hash algorithm.


I would like to propose separate EvpMdxxx.
EvpMdNew -> Sha256New, Sha384New
EvpMdInit -> Sha256Init, Sha384Init
EvpMdUpdate -> Sha256Update, Sha384Update
EvpMdFinal -> Sha256Final, Sha384Final
EvpMdFree -> Sha256Free, Sha384Free

We can do similar thing with Hmac, to deprecate Sha256GetContextSize() API, and replace caller with Sha256New() / Sha384Free()

Thank you
Yao Jiewen

-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 9:36 PM
To: Yao, Jiewen <jiewen.yao@...>; devel@edk2.groups.io; Zurcher,
Christopher J <christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

On 09/16/20 13:44, Yao, Jiewen wrote:
Hi Laszlo
I disagree to put OPTIONAL for DigestValue, just because NULL is checked.
If we need follow this, then we need add OPTIONAL to almost all pointer,
which is unnecessary.

I'm not suggesting OPTIONAL *only* because NULL is checked. I'm
suggesting OPTIONAL because there is a specific use case related to
that. Please see the comments on the function:

"If DigestValue is NULL, free the Context then return FALSE."

But, anyway, I don't insist. It's not a huge deal. Feel free to ignore
my comment regarding OPTIONAL.

Thanks
Laszlo



+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).




-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 7:07 PM
To: devel@edk2.groups.io; Zurcher, Christopher J
<christopher.j.zurcher@...>
Cc: Yao, Jiewen <jiewen.yao@...>; Wang, Jian J
<jian.j.wang@...>;
Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hello Christopher,

On 09/16/20 02:59, Zurcher, Christopher J wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257
++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128
++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128
++++++++++
9 files changed, 647 insertions(+)
I agree that "CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c"
is necessary. (If I understand correctly, that file was missing from
your v2 posting.)

But "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c" seems
superfluous. This file is never referenced in the INF files.

The point of this file would be to allow *some* of the Base / Pei /
Runtime / Smm instances to "stub out" the EVP MD functions (i.e. provide
only stub implementations). But this isn't what's happening -- all of
the Base / Pei / Runtime / Smm instances are getting the real deal
("CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c").

(1) So I think "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c"
should be dropped. Only the Null instance of the library needs null
versions of the new functions. The Base / Pei / Runtime / Smm instances
don't.


diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h
b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//==============================================================
=======================
+// EVP (Envelope) Primitive
+//==============================================================
=======================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(),
and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.

(2) Please extend the comment on Digest with the following:

The caller is responsible for providing enough storage for the digest
algorithm selected with EvpMdInit(). Providing EVP_MAX_MD_SIZE bytes
will suffice for storing the digest regardless of the algorithm chosen
in EvpMdInit().

(EVP_MAX_MD_SIZE is a public OpenSSL macro and I think we should openly
advertise it to consumers in edk2.)

+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).

+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//===============================================================
======================
// Symmetric Cryptography Primitive
//===============================================================
======================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
I think this may not compile with gcc (and correctly so). The pointer
returned by EVP_get_digestbyname() is const-qualified, but with the
assignment, we're throwing away the const-ness.

(4) Please const-qualify the "Digest" local pointer.

+ if (Digest == NULL) {
+ return NULL;
+ }
(5) This is a memory leak I believe; "EvpMdContext" is leaked.

For keeping the control flow simple, consider moving
EVP_get_digestbyname() above EVP_MD_CTX_new().

+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
(6) Can you please confirm that the caller is supposed to initialize
"NewEvpMdContext" with EvpMdInit() first, before calling EvpMdDuplicate()?

+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(),
and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in
OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }

(7) I suggest dropping the "Length" local variable. EVP_DigestFinal_ex()
deals fine with the third parameter being NULL, according to the docs
(and the code).


+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
(8) Style: please write (!Result).


+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
Thanks,
Laszlo


Laszlo Ersek
 

On 09/16/20 14:56, Yao, Jiewen wrote:
I try to understand what is the use case to EvpMdFinal without DigestValue and only Free the EvpMdContext.
Error paths. You got some hashing going, detect an error condition
(related to the hashing itself, or to something else), and want to abort
/ clean up the hashing. You need to release the context, but don't care
about the digest calculated thus far.

A normal usage will be:
1) EvpMdHashAll (Digest) - get digest.
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest) - get digest

Why we need support the case to use EvpMdFinal (NULL) in the end to free context?
We don't strictly need it. In the above (error path) use case, we can
still pass a pointer to an actual digest-receiving object, and then go
on to ignore the contents of that object. Passing NULL in that case
improves readability though.

Thanks
Laszlo



Thank you
Yao Jiewen

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Laszlo Ersek
Sent: Wednesday, September 16, 2020 8:40 PM
To: Yao, Jiewen <jiewen.yao@...>; devel@edk2.groups.io; Zurcher,
Christopher J <christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

On 09/16/20 14:07, Yao, Jiewen wrote:
I overlooked the behavior that NULL DigestValue will take side effect to free
Context.

Hi Christopher
May I understand why we need free the context?
This does not align with other existing HASH or HMAC functions.
I requested that.

It makes no sense to keep a finalized context.

In other words, it makes no sense to separate finalization from freeing.
A context that has been finalized is unusable for anything except freeing.

Thanks
Laszlo


Thank you
Yao Jiewen

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Yao,
Jiewen
Sent: Wednesday, September 16, 2020 7:45 PM
To: Laszlo Ersek <lersek@...>; devel@edk2.groups.io; Zurcher,
Christopher J <christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX
<xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hi Laszlo
I disagree to put OPTIONAL for DigestValue, just because NULL is checked.
If we need follow this, then we need add OPTIONAL to almost all pointer,
which
is unnecessary.

+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).




-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 7:07 PM
To: devel@edk2.groups.io; Zurcher, Christopher J
<christopher.j.zurcher@...>
Cc: Yao, Jiewen <jiewen.yao@...>; Wang, Jian J
<jian.j.wang@...>;
Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Hello Christopher,

On 09/16/20 02:59, Zurcher, Christopher J wrote:
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2545

The EVP interface should be used in place of discrete digest function
calls.

Cc: Laszlo Ersek <lersek@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Xiaoyu Lu <xiaoyux.lu@...>
Signed-off-by: Christopher J Zurcher <christopher.j.zurcher@...>
---
CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf | 1 +
CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf | 1 +
CryptoPkg/Include/Library/BaseCryptLib.h | 129 ++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c | 257
++++++++++++++++++++
CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c | 128
++++++++++
CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c | 128
++++++++++
9 files changed, 647 insertions(+)
I agree that "CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c"
is necessary. (If I understand correctly, that file was missing from
your v2 posting.)

But "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c" seems
superfluous. This file is never referenced in the INF files.

The point of this file would be to allow *some* of the Base / Pei /
Runtime / Smm instances to "stub out" the EVP MD functions (i.e. provide
only stub implementations). But this isn't what's happening -- all of
the Base / Pei / Runtime / Smm instances are getting the real deal
("CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c").

(1) So I think "CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c"
should be dropped. Only the Null instance of the library needs null
versions of the new functions. The Base / Pei / Runtime / Smm instances
don't.


diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95..3968f29412 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -50,6 +50,7 @@
Pk/CryptAuthenticode.c
Pk/CryptTs.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index dc28e3a11d..d0b91716d0 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -57,6 +57,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 5005beed02..9f3accd35b 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -56,6 +56,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/TimerWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf..420623cdc6 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -54,6 +54,7 @@
Pk/CryptAuthenticodeNull.c
Pk/CryptTsNull.c
Pem/CryptPem.c
+ Evp/CryptEvpMd.c

SysCall/CrtWrapper.c
SysCall/ConstantTimeClock.c
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd..542ac2e2e1 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,7 @@
Pk/CryptTsNull.c
Pem/CryptPemNull.c
Rand/CryptRandNull.c
+ Evp/CryptEvpMdNull.c

[Packages]
MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h
b/CryptoPkg/Include/Library/BaseCryptLib.h
index ae9bde9e37..5e1b408b54 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1012,6 +1012,135 @@ HmacSha256Final (
OUT UINT8 *HmacValue
);

+//==============================================================
=======================
+// EVP (Envelope) Primitive
+//==============================================================
=======================
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated
and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ );
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ );
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(),
and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ );
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP
context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.

(2) Please extend the comment on Digest with the following:

The caller is responsible for providing enough storage for the digest
algorithm selected with EvpMdInit(). Providing EVP_MAX_MD_SIZE bytes
will suffice for storing the digest regardless of the algorithm chosen
in EvpMdInit().

(EVP_MAX_MD_SIZE is a public OpenSSL macro and I think we should openly
advertise it to consumers in edk2.)

+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
(3) DigestValue should be marked OPTIONAL in my opinion, as NULL is
deliberately permitted (for just freeing the context).

+ );
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ );
+
//===============================================================
======================
// Symmetric Cryptography Primitive
//===============================================================
======================
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
new file mode 100644
index 0000000000..b2770a9186
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMd.c
@@ -0,0 +1,257 @@
+/** @file
+ EVP MD Wrapper Implementation for OpenSSL.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/evp.h>
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ If DigestName is NULL, then return FALSE.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return Pointer to the EVP_MD_CTX context that has been allocated
and
initialized.
+ If DigestName is invalid, returns NULL.
+ If the allocations fails, returns NULL.
+ If initialization fails, returns NULL.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ EVP_MD *Digest;
+ VOID *EvpMdContext;
+
+ //
+ // Check input parameters.
+ //
+ if (DigestName == NULL) {
+ return NULL;
+ }
+
+ //
+ // Allocate EVP_MD_CTX Context
+ //
+ EvpMdContext = EVP_MD_CTX_new ();
+ if (EvpMdContext == NULL) {
+ return NULL;
+ }
+
+ Digest = EVP_get_digestbyname (DigestName);
I think this may not compile with gcc (and correctly so). The pointer
returned by EVP_get_digestbyname() is const-qualified, but with the
assignment, we're throwing away the const-ness.

(4) Please const-qualify the "Digest" local pointer.

+ if (Digest == NULL) {
+ return NULL;
+ }
(5) This is a memory leak I believe; "EvpMdContext" is leaked.

For keeping the control flow simple, consider moving
EVP_get_digestbyname() above EVP_MD_CTX_new().

+
+ //
+ // Initialize Context
+ //
+ if (EVP_DigestInit_ex (EvpMdContext, Digest, NULL) != 1) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return NULL;
+ }
+
+ return EvpMdContext;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If NewEvpMdContext is NULL, then return FALSE.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval TRUE EVP_MD context copy succeeded.
+ @retval FALSE EVP_MD context copy failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL || NewEvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ if (EVP_MD_CTX_copy (NewEvpMdContext, EvpMdContext) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
(6) Can you please confirm that the caller is supposed to initialize
"NewEvpMdContext" with EvpMdInit() first, before calling EvpMdDuplicate()?

+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ This function performs EVP digest on a data buffer of the specified size.
+ It can be called multiple times to compute the digest of long or
discontinuous data streams.
+ EVP_MD context should be already correctly initialized by EvpMdInit(),
and
should not
+ be finalized by EvpMdFinal(). Behavior with invalid context is undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval TRUE EVP data digest succeeded.
+ @retval FALSE EVP data digest failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ //
+ // Check invalid parameters, in case only DataLength was checked in
OpenSSL
+ //
+ if (Data == NULL && DataSize != 0) {
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest update
+ //
+ if (EVP_DigestUpdate (EvpMdContext, Data, DataSize) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ This function completes EVP hash computation and retrieves the digest
value into
+ the specified memory. After this function has been called, the EVP
context
cannot
+ be used again.
+ EVP context should be already correctly initialized by EvpMdInit(), and
should
+ not be finalized by EvpMdFinal(). Behavior with invalid EVP context is
undefined.
+
+ If EvpMdContext is NULL, then return FALSE.
+ If DigestValue is NULL, free the Context then return FALSE.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval TRUE EVP digest computation succeeded.
+ @retval FALSE EVP digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ UINT32 Length;
+ BOOLEAN ReturnValue;
+
+ ReturnValue = TRUE;
+
+ //
+ // Check input parameters.
+ //
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+ if (DigestValue == NULL) {
+ EVP_MD_CTX_free (EvpMdContext);
+ return FALSE;
+ }
+
+ //
+ // OpenSSL EVP digest finalization
+ //
+ if (EVP_DigestFinal_ex (EvpMdContext, DigestValue, &Length) != 1) {
+ ReturnValue = FALSE;
+ }

(7) I suggest dropping the "Length" local variable. EVP_DigestFinal_ex()
deals fine with the third parameter being NULL, according to the docs
(and the code).


+
+ //
+ // Free OpenSSL EVP_MD_CTX Context
+ //
+ EVP_MD_CTX_free (EvpMdContext);
+
+ return ReturnValue;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ This function performs the message digest of a given data buffer, and
places
+ the digest value into the specified memory.
+
+ If DigestName is NULL, return FALSE.
+ If Data is NULL and DataSize is not zero, return FALSE.
+ If HashValue is NULL, return FALSE.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval TRUE Digest computation succeeded.
+ @retval FALSE Digest computation failed.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ BOOLEAN Result;
+ VOID *EvpMdContext;
+
+ EvpMdContext = EvpMdInit (DigestName);
+ if (EvpMdContext == NULL) {
+ return FALSE;
+ }
+
+ Result = EvpMdUpdate (EvpMdContext, Data, DataSize);
+ if (Result == FALSE) {
(8) Style: please write (!Result).


+ EvpMdFinal (EvpMdContext, NULL);
+ return FALSE;
+ }
+
+ Result = EvpMdFinal (EvpMdContext, HashValue);
+
+ return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
new file mode 100644
index 0000000000..038f63801f
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Evp/CryptEvpMdNull.c
@@ -0,0 +1,128 @@
+/** @file
+ EVP MD Wrapper Null Library.
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+ Allocates and initializes one EVP_MD_CTX context for subsequent
EVP_MD
use.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name as a NULL-
terminated ASCII string.
+ Valid digest names are:
+ MD5, SHA1, SHA224, SHA256, SHA384, SHA512
+ SHA3-224, SHA3-256, SHA3-384, SHA3-512
+ SM3
+
+ @return NULL This interface is not supported.
+
+**/
+VOID *
+EFIAPI
+EvpMdInit (
+ IN CONST CHAR8 *DigestName
+ )
+{
+ ASSERT (FALSE);
+ return NULL;
+}
+
+/**
+ Makes a copy of an existing EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] EvpMdContext Pointer to EVP_MD context being copied.
+ @param[out] NewEvpMdContext Pointer to new EVP_MD context.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdDuplicate (
+ IN CONST VOID *EvpMdContext,
+ OUT VOID *NewEvpMdContext
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Digests the input data and updates EVP_MD context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP_MD context.
+ @param[in] Data Pointer to the buffer containing the data to
be
digested.
+ @param[in] DataSize Size of Data buffer in bytes.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdUpdate (
+ IN OUT VOID *EvpMdContext,
+ IN CONST VOID *Data,
+ IN UINTN DataSize
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Completes computation of the EVP digest value.
+ Releases the specified EVP_MD_CTX context.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in, out] EvpMdContext Pointer to the EVP context.
+ @param[out] Digest Pointer to a buffer that receives the EVP
digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdFinal (
+ IN OUT VOID *EvpMdContext,
+ OUT UINT8 *DigestValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
+
+/**
+ Computes the message digest of an input data buffer.
+
+ Return FALSE to indicate this interface is not supported.
+
+ @param[in] DigestName Pointer to the digest name.
+ @param[in] Data Pointer to the buffer containing the data to be
hashed.
+ @param[in] DataSize Size of Data buffer in bytes.
+ @param[out] HashValue Pointer to a buffer that receives the digest
value.
+
+ @retval FALSE This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+EvpMdHashAll (
+ IN CONST CHAR8 *DigestName,
+ IN CONST VOID *Data,
+ IN UINTN DataSize,
+ OUT UINT8 *HashValue
+ )
+{
+ ASSERT (FALSE);
+ return FALSE;
+}
Thanks,
Laszlo



Laszlo Ersek
 

On 09/16/20 16:17, Yao, Jiewen wrote:
Thank you Laszlo.
You forced me to read the code again and more carefully. :-)

I believe I understand why you use NULL to free the context now - to support error path.

First, I did have some new thought for EVP API. Let’s consider 3 cases, 1) Hash all data one time, 2) Hash update data multiple times, 3) Error during update.

A. In current design, the API sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR, EvpMdFinal (NULL)

B. We can auto free context in EvpMdUpdate in error path - the API sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR
I don't like "B" because in the loop body where you call EvpMdUpdate(),
you may encounter an error from a different source than EvpMdUpdate()
itself. For example, you may be reading data from the network or a disk
file. If fetching the next chunk fails, we'd still want to clean up the
EVP MD context. Therefore, if EvpMdUpdate() would itself invalidate the
context, if it failed, then that would *complicate* the error path. (=
Clean up the context after the loop body *only* if something different
from EvpMdUpdate() failed.)


C: We can use New/Free style - similar to HMAC
1) EvpMdHashAll (Digest)
2) EvpMdNew, EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest), EvpMdFree
3) EvpMdNew, EvpMdInit, EvpMdUpdate->ERROR, EvpMdFree
Yes, this was the first pattern, the one that caused me to say "please
don't do this". In this pattern, the context may exist between "New" and
"Init", and also between "Final" and "Free". Those two states are
useless and only good for causing confusion.

For example, are you allowed to Duplicate a context in those states?
It's best to prevent even the *asking* of that question.


I checked below APIs:
1) openssl (EVP_MD_CTX_new, EVP_DigestInit_ex, EVP_DigestUpdate, EVP_DigestFinal_ex, EVP_MD_CTX_free)
2) mbedtls (mbedtls_sha256_init, mbedtls_sha256_starts_ret, mbedtls_sha256_update_ret, mbedtls_sha256_finish_ret, mbedtls_sha256_free)
3) BaseCryptoLib HMAC (HmacSha256New, HmacSha256SetKey, HmacSha256Update, HmacSha256Final, HmacSha256Free)

All APIs include free function to free the context, I don’t think it is a bad idea to have EvpMdFree() API.
I would like to propose option - C.
- I cannot comment on mbedtls (2).

- I think the current BaseCryptLib HMAC APIs (3) are not great, and we
should use this opportunity to improve upon them.

- Regarding openssl (1), as I understand it, the situation is different
from edk2. In OpenSSL, EVP_MD_CTX is *not* an opaque type (expressed in
C language terms, it is not an "incomplete" type, but a "complete"
type). Therefore, an expression such as sizeof(EVP_MD_CTX) works.

The consequence is that OpenSSL code itself can use the following style:

void func(void)
{
EVP_MD_CTX ctx;

EVP_DigestInit_ex(&ctx, ...);
...
EVP_DigestFinal_ex(&ctx, ...)
}

In other words, OpenSSL-native code is permitted to know the internals
of EVP_MD_CTX, therefore the OpenSSL-internal code may allocate
EVP_MD_CTX with means that are *different* from EVP_MD_CTX_new() and
EVP_MD_CTX_free().

The caller of (Init, Final) may use (New, Free) for memory management,
or may use something completely different (for example, local variables).

Therefore, offering the (Init, Final) APIs separately from (New, Free)
is meaningful.

But the situation in edk2 -- or any other OpenSSL *consumer* -- is
different. In edk2, EVP_MD_CTX is an opaque type -- in C language terms:
an "incomplete" type. OpenSSL deliberately hides the internals of
EVP_MD_CTX.

See "CryptoPkg/Library/OpensslLib/openssl/include/openssl/ossl_typ.h":

typedef struct evp_md_ctx_st EVP_MD_CTX;
and the "evp_md_ctx_st" structure type is only defined in
"CryptoPkg/Library/OpensslLib/openssl/crypto/evp/evp_local.h", whose
contents -- I think! -- OpenSSL client code cannot, or *should not*,
refer to.

This means that OpenSSL consumer code can *only* rely on
EVP_MD_CTX_new() and EVP_MD_CTX_free(), for allocating and releasing the
context, respectively. "sizeof(EVP_MD_CTX)" is not permitted, and
defining a local or global variable of type EVP_MD_CTX is also not valid.

This means that the only reason for separating (Init, Final) from (New,
Free) falls away, in OpenSSL consumer code. In OpenSSL consumer code,
there is no reason to keep *both* pairs of APIs.


Please note that, this (very prudent) information hiding / encapsulation
in OpenSSL used to be violated by edk2 in the past, intentionally.
That's what the HmacXxxGetContextSize() APIs were about -- those APIs
forcefully leaked the context sizes to client code, so that client code
in edk2 could perform its own allocation.

But in <https://bugzilla.tianocore.org/show_bug.cgi?id=1792>, we finally
eliminated HmacXxxGetContextSize(). As a part of that, we also
simplified the HMAC API -- note that Init was replaced by SetKey. And
because we were reworking an existent API, I didn't propose very
intrusive changes -- I didn't propose fusing Final and Free, for example.

Now, the EVP MD APIs are just being introduced to edk2. So we have a
chance at getting them right, and making them minimal.

Second, I believe EVP is just something in openssl. It does not mean that we *have to* design API to follow openssl.
After rethink the size impact, I do have concern to merge all Hash implementation together in one function.
It might means nothing if the crypto library is based upon openssl.
But if the cryptolib implementation is based upon other crypto, such as Intel IPP (https://github.com/slimbootloader/slimbootloader/tree/master/BootloaderCommonPkg/Library/IppCryptoLib) or mbedTls (https://github.com/jyao1/edk2/tree/DeviceSecurity/CryptoMbedTlsPkg), then we can NOT get size benefit by separating the hash algorithm.


I would like to propose separate EvpMdxxx.
EvpMdNew -> Sha256New, Sha384New
EvpMdInit -> Sha256Init, Sha384Init
EvpMdUpdate -> Sha256Update, Sha384Update
EvpMdFinal -> Sha256Final, Sha384Final
EvpMdFree -> Sha256Free, Sha384Free
I have no comment on this.

We can do similar thing with Hmac, to deprecate Sha256GetContextSize() API,
Yes, good idea.

and replace caller with Sha256New() / Sha384Free()
Indeed.

But then -- there's no reason left for keeping (New, Free) separate from
(Init, Final).

Thanks
Laszlo


Zurcher, Christopher J
 

Jiewen,

This patch set assumes that EDK2 is linked with OpenSSL for the foreseeable future. The end goal would be to move all applicable Crypto access to the EVP interface and remove the individual modules we maintain for each algorithm. The primary benefit here is reducing complexity and code duplication. Without this end goal, this patch set will not be particularly useful.

If the design goal of BaseCryptLib is to allow OpenSSL to be replaced by other crypto providers, I should abandon this patch set, and we can save the EVP transition for when moving to OpenSSL 3 becomes mandatory. At that time, the CryptX.c family can be modified to call EVP functions.
(This could even be done transparently, by returning UINTN from GetContextSize and using the user-supplied "context" to store the OpenSSL-supplied context pointer.)
Delaying EVP adoption in this case would also allow more time for platforms to adopt the Crypto Services model, which should help offset the size impact.

Please let me know which path should be taken.

Thanks,
Christopher Zurcher

-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 09:05
To: Yao, Jiewen <jiewen.yao@...>; devel@edk2.groups.io; Zurcher, Christopher J
<christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP (Envelope) Digest interface

On 09/16/20 16:17, Yao, Jiewen wrote:
Thank you Laszlo.
You forced me to read the code again and more carefully. :-)

I believe I understand why you use NULL to free the context now - to support error path.

First, I did have some new thought for EVP API. Let’s consider 3 cases, 1) Hash all data one time, 2) Hash update
data multiple times, 3) Error during update.

A. In current design, the API sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR, EvpMdFinal (NULL)

B. We can auto free context in EvpMdUpdate in error path - the API sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR
I don't like "B" because in the loop body where you call EvpMdUpdate(),
you may encounter an error from a different source than EvpMdUpdate()
itself. For example, you may be reading data from the network or a disk
file. If fetching the next chunk fails, we'd still want to clean up the
EVP MD context. Therefore, if EvpMdUpdate() would itself invalidate the
context, if it failed, then that would *complicate* the error path. (=
Clean up the context after the loop body *only* if something different
from EvpMdUpdate() failed.)


C: We can use New/Free style - similar to HMAC
1) EvpMdHashAll (Digest)
2) EvpMdNew, EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest), EvpMdFree
3) EvpMdNew, EvpMdInit, EvpMdUpdate->ERROR, EvpMdFree
Yes, this was the first pattern, the one that caused me to say "please
don't do this". In this pattern, the context may exist between "New" and
"Init", and also between "Final" and "Free". Those two states are
useless and only good for causing confusion.

For example, are you allowed to Duplicate a context in those states?
It's best to prevent even the *asking* of that question.


I checked below APIs:
1) openssl (EVP_MD_CTX_new, EVP_DigestInit_ex, EVP_DigestUpdate, EVP_DigestFinal_ex, EVP_MD_CTX_free)
2) mbedtls (mbedtls_sha256_init, mbedtls_sha256_starts_ret, mbedtls_sha256_update_ret, mbedtls_sha256_finish_ret,
mbedtls_sha256_free)
3) BaseCryptoLib HMAC (HmacSha256New, HmacSha256SetKey, HmacSha256Update, HmacSha256Final, HmacSha256Free)

All APIs include free function to free the context, I don’t think it is a bad idea to have EvpMdFree() API.
I would like to propose option - C.
- I cannot comment on mbedtls (2).

- I think the current BaseCryptLib HMAC APIs (3) are not great, and we
should use this opportunity to improve upon them.

- Regarding openssl (1), as I understand it, the situation is different
from edk2. In OpenSSL, EVP_MD_CTX is *not* an opaque type (expressed in
C language terms, it is not an "incomplete" type, but a "complete"
type). Therefore, an expression such as sizeof(EVP_MD_CTX) works.

The consequence is that OpenSSL code itself can use the following style:

void func(void)
{
EVP_MD_CTX ctx;

EVP_DigestInit_ex(&ctx, ...);
...
EVP_DigestFinal_ex(&ctx, ...)
}

In other words, OpenSSL-native code is permitted to know the internals
of EVP_MD_CTX, therefore the OpenSSL-internal code may allocate
EVP_MD_CTX with means that are *different* from EVP_MD_CTX_new() and
EVP_MD_CTX_free().

The caller of (Init, Final) may use (New, Free) for memory management,
or may use something completely different (for example, local variables).

Therefore, offering the (Init, Final) APIs separately from (New, Free)
is meaningful.

But the situation in edk2 -- or any other OpenSSL *consumer* -- is
different. In edk2, EVP_MD_CTX is an opaque type -- in C language terms:
an "incomplete" type. OpenSSL deliberately hides the internals of
EVP_MD_CTX.

See "CryptoPkg/Library/OpensslLib/openssl/include/openssl/ossl_typ.h":

typedef struct evp_md_ctx_st EVP_MD_CTX;
and the "evp_md_ctx_st" structure type is only defined in
"CryptoPkg/Library/OpensslLib/openssl/crypto/evp/evp_local.h", whose
contents -- I think! -- OpenSSL client code cannot, or *should not*,
refer to.

This means that OpenSSL consumer code can *only* rely on
EVP_MD_CTX_new() and EVP_MD_CTX_free(), for allocating and releasing the
context, respectively. "sizeof(EVP_MD_CTX)" is not permitted, and
defining a local or global variable of type EVP_MD_CTX is also not valid.

This means that the only reason for separating (Init, Final) from (New,
Free) falls away, in OpenSSL consumer code. In OpenSSL consumer code,
there is no reason to keep *both* pairs of APIs.


Please note that, this (very prudent) information hiding / encapsulation
in OpenSSL used to be violated by edk2 in the past, intentionally.
That's what the HmacXxxGetContextSize() APIs were about -- those APIs
forcefully leaked the context sizes to client code, so that client code
in edk2 could perform its own allocation.

But in <https://bugzilla.tianocore.org/show_bug.cgi?id=1792>, we finally
eliminated HmacXxxGetContextSize(). As a part of that, we also
simplified the HMAC API -- note that Init was replaced by SetKey. And
because we were reworking an existent API, I didn't propose very
intrusive changes -- I didn't propose fusing Final and Free, for example.

Now, the EVP MD APIs are just being introduced to edk2. So we have a
chance at getting them right, and making them minimal.

Second, I believe EVP is just something in openssl. It does not mean that we *have to* design API to follow
openssl.
After rethink the size impact, I do have concern to merge all Hash implementation together in one function.
It might means nothing if the crypto library is based upon openssl.
But if the cryptolib implementation is based upon other crypto, such as Intel IPP
(https://github.com/slimbootloader/slimbootloader/tree/master/BootloaderCommonPkg/Library/IppCryptoLib) or mbedTls
(https://github.com/jyao1/edk2/tree/DeviceSecurity/CryptoMbedTlsPkg), then we can NOT get size benefit by separating
the hash algorithm.


I would like to propose separate EvpMdxxx.
EvpMdNew -> Sha256New, Sha384New
EvpMdInit -> Sha256Init, Sha384Init
EvpMdUpdate -> Sha256Update, Sha384Update
EvpMdFinal -> Sha256Final, Sha384Final
EvpMdFree -> Sha256Free, Sha384Free
I have no comment on this.

We can do similar thing with Hmac, to deprecate Sha256GetContextSize() API,
Yes, good idea.

and replace caller with Sha256New() / Sha384Free()
Indeed.

But then -- there's no reason left for keeping (New, Free) separate from
(Init, Final).

Thanks
Laszlo


Yao, Jiewen
 

Thanks to ask this question Christopher.

When we create the CryptoPkg, our goal is to pick openssl as implementation choice. We don’t want to mandate any EDKII consumer use openssl.

The EDKII consumer shall have freedom to choose whatever crypto library they want to use. Even Intel IPP and mebdTLS are options. A vendor may choose a GPL wolfssl, or vendor proprietary close source implementation. We choose openssl just because it is the BSD license and it is used widely when we make decision.

That is why we spend effort to design BaseCryptoLib API to abstract the crypto action, instead of calling openssl function directly in our code.
Whenever we add new API, we need evaluate if it is applicable for any other crypto implantation and have negative impact.

That assumption that EDKII must link openssl is NOT our original intent.
Feel free to drop the patch or reject the Bugzilla, if you want.

Thank you
Yao Jiewen

-----Original Message-----
From: Zurcher, Christopher J <christopher.j.zurcher@...>
Sent: Thursday, September 17, 2020 9:21 AM
To: Laszlo Ersek <lersek@...>; Yao, Jiewen <jiewen.yao@...>;
devel@edk2.groups.io
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: RE: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Jiewen,

This patch set assumes that EDK2 is linked with OpenSSL for the foreseeable
future. The end goal would be to move all applicable Crypto access to the EVP
interface and remove the individual modules we maintain for each algorithm.
The primary benefit here is reducing complexity and code duplication. Without
this end goal, this patch set will not be particularly useful.

If the design goal of BaseCryptLib is to allow OpenSSL to be replaced by other
crypto providers, I should abandon this patch set, and we can save the EVP
transition for when moving to OpenSSL 3 becomes mandatory. At that time, the
CryptX.c family can be modified to call EVP functions.
(This could even be done transparently, by returning UINTN from GetContextSize
and using the user-supplied "context" to store the OpenSSL-supplied context
pointer.)
Delaying EVP adoption in this case would also allow more time for platforms to
adopt the Crypto Services model, which should help offset the size impact.

Please let me know which path should be taken.

Thanks,
Christopher Zurcher

-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 09:05
To: Yao, Jiewen <jiewen.yao@...>; devel@edk2.groups.io; Zurcher,
Christopher J
<christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

On 09/16/20 16:17, Yao, Jiewen wrote:
Thank you Laszlo.
You forced me to read the code again and more carefully. :-)

I believe I understand why you use NULL to free the context now - to support
error path.

First, I did have some new thought for EVP API. Let’s consider 3 cases, 1)
Hash all data one time, 2) Hash update
data multiple times, 3) Error during update.

A. In current design, the API sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR, EvpMdFinal (NULL)

B. We can auto free context in EvpMdUpdate in error path - the API
sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR
I don't like "B" because in the loop body where you call EvpMdUpdate(),
you may encounter an error from a different source than EvpMdUpdate()
itself. For example, you may be reading data from the network or a disk
file. If fetching the next chunk fails, we'd still want to clean up the
EVP MD context. Therefore, if EvpMdUpdate() would itself invalidate the
context, if it failed, then that would *complicate* the error path. (=
Clean up the context after the loop body *only* if something different
from EvpMdUpdate() failed.)


C: We can use New/Free style - similar to HMAC
1) EvpMdHashAll (Digest)
2) EvpMdNew, EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal
(Digest), EvpMdFree
3) EvpMdNew, EvpMdInit, EvpMdUpdate->ERROR, EvpMdFree
Yes, this was the first pattern, the one that caused me to say "please
don't do this". In this pattern, the context may exist between "New" and
"Init", and also between "Final" and "Free". Those two states are
useless and only good for causing confusion.

For example, are you allowed to Duplicate a context in those states?
It's best to prevent even the *asking* of that question.


I checked below APIs:
1) openssl (EVP_MD_CTX_new, EVP_DigestInit_ex, EVP_DigestUpdate,
EVP_DigestFinal_ex, EVP_MD_CTX_free)
2) mbedtls (mbedtls_sha256_init, mbedtls_sha256_starts_ret,
mbedtls_sha256_update_ret, mbedtls_sha256_finish_ret,
mbedtls_sha256_free)
3) BaseCryptoLib HMAC (HmacSha256New, HmacSha256SetKey,
HmacSha256Update, HmacSha256Final, HmacSha256Free)

All APIs include free function to free the context, I don’t think it is a bad idea
to have EvpMdFree() API.
I would like to propose option - C.
- I cannot comment on mbedtls (2).

- I think the current BaseCryptLib HMAC APIs (3) are not great, and we
should use this opportunity to improve upon them.

- Regarding openssl (1), as I understand it, the situation is different
from edk2. In OpenSSL, EVP_MD_CTX is *not* an opaque type (expressed in
C language terms, it is not an "incomplete" type, but a "complete"
type). Therefore, an expression such as sizeof(EVP_MD_CTX) works.

The consequence is that OpenSSL code itself can use the following style:

void func(void)
{
EVP_MD_CTX ctx;

EVP_DigestInit_ex(&ctx, ...);
...
EVP_DigestFinal_ex(&ctx, ...)
}

In other words, OpenSSL-native code is permitted to know the internals
of EVP_MD_CTX, therefore the OpenSSL-internal code may allocate
EVP_MD_CTX with means that are *different* from EVP_MD_CTX_new() and
EVP_MD_CTX_free().

The caller of (Init, Final) may use (New, Free) for memory management,
or may use something completely different (for example, local variables).

Therefore, offering the (Init, Final) APIs separately from (New, Free)
is meaningful.

But the situation in edk2 -- or any other OpenSSL *consumer* -- is
different. In edk2, EVP_MD_CTX is an opaque type -- in C language terms:
an "incomplete" type. OpenSSL deliberately hides the internals of
EVP_MD_CTX.

See "CryptoPkg/Library/OpensslLib/openssl/include/openssl/ossl_typ.h":

typedef struct evp_md_ctx_st EVP_MD_CTX;
and the "evp_md_ctx_st" structure type is only defined in
"CryptoPkg/Library/OpensslLib/openssl/crypto/evp/evp_local.h", whose
contents -- I think! -- OpenSSL client code cannot, or *should not*,
refer to.

This means that OpenSSL consumer code can *only* rely on
EVP_MD_CTX_new() and EVP_MD_CTX_free(), for allocating and releasing the
context, respectively. "sizeof(EVP_MD_CTX)" is not permitted, and
defining a local or global variable of type EVP_MD_CTX is also not valid.

This means that the only reason for separating (Init, Final) from (New,
Free) falls away, in OpenSSL consumer code. In OpenSSL consumer code,
there is no reason to keep *both* pairs of APIs.


Please note that, this (very prudent) information hiding / encapsulation
in OpenSSL used to be violated by edk2 in the past, intentionally.
That's what the HmacXxxGetContextSize() APIs were about -- those APIs
forcefully leaked the context sizes to client code, so that client code
in edk2 could perform its own allocation.

But in <https://bugzilla.tianocore.org/show_bug.cgi?id=1792>, we finally
eliminated HmacXxxGetContextSize(). As a part of that, we also
simplified the HMAC API -- note that Init was replaced by SetKey. And
because we were reworking an existent API, I didn't propose very
intrusive changes -- I didn't propose fusing Final and Free, for example.

Now, the EVP MD APIs are just being introduced to edk2. So we have a
chance at getting them right, and making them minimal.

Second, I believe EVP is just something in openssl. It does not mean that we
*have to* design API to follow
openssl.
After rethink the size impact, I do have concern to merge all Hash
implementation together in one function.
It might means nothing if the crypto library is based upon openssl.
But if the cryptolib implementation is based upon other crypto, such as Intel
IPP
(https://github.com/slimbootloader/slimbootloader/tree/master/BootloaderCo
mmonPkg/Library/IppCryptoLib) or mbedTls
(https://github.com/jyao1/edk2/tree/DeviceSecurity/CryptoMbedTlsPkg), then
we can NOT get size benefit by separating
the hash algorithm.


I would like to propose separate EvpMdxxx.
EvpMdNew -> Sha256New, Sha384New
EvpMdInit -> Sha256Init, Sha384Init
EvpMdUpdate -> Sha256Update, Sha384Update
EvpMdFinal -> Sha256Final, Sha384Final
EvpMdFree -> Sha256Free, Sha384Free
I have no comment on this.

We can do similar thing with Hmac, to deprecate Sha256GetContextSize()
API,

Yes, good idea.

and replace caller with Sha256New() / Sha384Free()
Indeed.

But then -- there's no reason left for keeping (New, Free) separate from
(Init, Final).

Thanks
Laszlo


Zurcher, Christopher J
 

OK, abandoning this patch set.

The BZ can stay open as we will still have to migrate the existing files to EVP eventually.

--
Christopher Zurcher

-----Original Message-----
From: Yao, Jiewen <jiewen.yao@...>
Sent: Wednesday, September 16, 2020 18:34
To: Zurcher, Christopher J <christopher.j.zurcher@...>; Laszlo Ersek <lersek@...>; devel@edk2.groups.io
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: RE: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP (Envelope) Digest interface

Thanks to ask this question Christopher.

When we create the CryptoPkg, our goal is to pick openssl as implementation choice. We don’t want to mandate any
EDKII consumer use openssl.

The EDKII consumer shall have freedom to choose whatever crypto library they want to use. Even Intel IPP and mebdTLS
are options. A vendor may choose a GPL wolfssl, or vendor proprietary close source implementation. We choose openssl
just because it is the BSD license and it is used widely when we make decision.

That is why we spend effort to design BaseCryptoLib API to abstract the crypto action, instead of calling openssl
function directly in our code.
Whenever we add new API, we need evaluate if it is applicable for any other crypto implantation and have negative
impact.

That assumption that EDKII must link openssl is NOT our original intent.
Feel free to drop the patch or reject the Bugzilla, if you want.

Thank you
Yao Jiewen

-----Original Message-----
From: Zurcher, Christopher J <christopher.j.zurcher@...>
Sent: Thursday, September 17, 2020 9:21 AM
To: Laszlo Ersek <lersek@...>; Yao, Jiewen <jiewen.yao@...>;
devel@edk2.groups.io
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: RE: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

Jiewen,

This patch set assumes that EDK2 is linked with OpenSSL for the foreseeable
future. The end goal would be to move all applicable Crypto access to the EVP
interface and remove the individual modules we maintain for each algorithm.
The primary benefit here is reducing complexity and code duplication. Without
this end goal, this patch set will not be particularly useful.

If the design goal of BaseCryptLib is to allow OpenSSL to be replaced by other
crypto providers, I should abandon this patch set, and we can save the EVP
transition for when moving to OpenSSL 3 becomes mandatory. At that time, the
CryptX.c family can be modified to call EVP functions.
(This could even be done transparently, by returning UINTN from GetContextSize
and using the user-supplied "context" to store the OpenSSL-supplied context
pointer.)
Delaying EVP adoption in this case would also allow more time for platforms to
adopt the Crypto Services model, which should help offset the size impact.

Please let me know which path should be taken.

Thanks,
Christopher Zurcher

-----Original Message-----
From: Laszlo Ersek <lersek@...>
Sent: Wednesday, September 16, 2020 09:05
To: Yao, Jiewen <jiewen.yao@...>; devel@edk2.groups.io; Zurcher,
Christopher J
<christopher.j.zurcher@...>
Cc: Wang, Jian J <jian.j.wang@...>; Lu, XiaoyuX <xiaoyux.lu@...>
Subject: Re: [edk2-devel] [PATCH v3 1/3] CryptoPkg/BaseCryptLib: Add EVP
(Envelope) Digest interface

On 09/16/20 16:17, Yao, Jiewen wrote:
Thank you Laszlo.
You forced me to read the code again and more carefully. :-)

I believe I understand why you use NULL to free the context now - to support
error path.

First, I did have some new thought for EVP API. Let’s consider 3 cases, 1)
Hash all data one time, 2) Hash update
data multiple times, 3) Error during update.

A. In current design, the API sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR, EvpMdFinal (NULL)

B. We can auto free context in EvpMdUpdate in error path - the API
sequence is:
1) EvpMdHashAll (Digest)
2) EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal (Digest)
3) EvpMdInit, EvpMdUpdate->ERROR
I don't like "B" because in the loop body where you call EvpMdUpdate(),
you may encounter an error from a different source than EvpMdUpdate()
itself. For example, you may be reading data from the network or a disk
file. If fetching the next chunk fails, we'd still want to clean up the
EVP MD context. Therefore, if EvpMdUpdate() would itself invalidate the
context, if it failed, then that would *complicate* the error path. (=
Clean up the context after the loop body *only* if something different
from EvpMdUpdate() failed.)


C: We can use New/Free style - similar to HMAC
1) EvpMdHashAll (Digest)
2) EvpMdNew, EvpMdInit, EvpMdUpdate, EvpMdUpdate, ... , EvpMdFinal
(Digest), EvpMdFree
3) EvpMdNew, EvpMdInit, EvpMdUpdate->ERROR, EvpMdFree
Yes, this was the first pattern, the one that caused me to say "please
don't do this". In this pattern, the context may exist between "New" and
"Init", and also between "Final" and "Free". Those two states are
useless and only good for causing confusion.

For example, are you allowed to Duplicate a context in those states?
It's best to prevent even the *asking* of that question.


I checked below APIs:
1) openssl (EVP_MD_CTX_new, EVP_DigestInit_ex, EVP_DigestUpdate,
EVP_DigestFinal_ex, EVP_MD_CTX_free)
2) mbedtls (mbedtls_sha256_init, mbedtls_sha256_starts_ret,
mbedtls_sha256_update_ret, mbedtls_sha256_finish_ret,
mbedtls_sha256_free)
3) BaseCryptoLib HMAC (HmacSha256New, HmacSha256SetKey,
HmacSha256Update, HmacSha256Final, HmacSha256Free)

All APIs include free function to free the context, I don’t think it is a bad idea
to have EvpMdFree() API.
I would like to propose option - C.
- I cannot comment on mbedtls (2).

- I think the current BaseCryptLib HMAC APIs (3) are not great, and we
should use this opportunity to improve upon them.

- Regarding openssl (1), as I understand it, the situation is different
from edk2. In OpenSSL, EVP_MD_CTX is *not* an opaque type (expressed in
C language terms, it is not an "incomplete" type, but a "complete"
type). Therefore, an expression such as sizeof(EVP_MD_CTX) works.

The consequence is that OpenSSL code itself can use the following style:

void func(void)
{
EVP_MD_CTX ctx;

EVP_DigestInit_ex(&ctx, ...);
...
EVP_DigestFinal_ex(&ctx, ...)
}

In other words, OpenSSL-native code is permitted to know the internals
of EVP_MD_CTX, therefore the OpenSSL-internal code may allocate
EVP_MD_CTX with means that are *different* from EVP_MD_CTX_new() and
EVP_MD_CTX_free().

The caller of (Init, Final) may use (New, Free) for memory management,
or may use something completely different (for example, local variables).

Therefore, offering the (Init, Final) APIs separately from (New, Free)
is meaningful.

But the situation in edk2 -- or any other OpenSSL *consumer* -- is
different. In edk2, EVP_MD_CTX is an opaque type -- in C language terms:
an "incomplete" type. OpenSSL deliberately hides the internals of
EVP_MD_CTX.

See "CryptoPkg/Library/OpensslLib/openssl/include/openssl/ossl_typ.h":

typedef struct evp_md_ctx_st EVP_MD_CTX;
and the "evp_md_ctx_st" structure type is only defined in
"CryptoPkg/Library/OpensslLib/openssl/crypto/evp/evp_local.h", whose
contents -- I think! -- OpenSSL client code cannot, or *should not*,
refer to.

This means that OpenSSL consumer code can *only* rely on
EVP_MD_CTX_new() and EVP_MD_CTX_free(), for allocating and releasing the
context, respectively. "sizeof(EVP_MD_CTX)" is not permitted, and
defining a local or global variable of type EVP_MD_CTX is also not valid.

This means that the only reason for separating (Init, Final) from (New,
Free) falls away, in OpenSSL consumer code. In OpenSSL consumer code,
there is no reason to keep *both* pairs of APIs.


Please note that, this (very prudent) information hiding / encapsulation
in OpenSSL used to be violated by edk2 in the past, intentionally.
That's what the HmacXxxGetContextSize() APIs were about -- those APIs
forcefully leaked the context sizes to client code, so that client code
in edk2 could perform its own allocation.

But in <https://bugzilla.tianocore.org/show_bug.cgi?id=1792>, we finally
eliminated HmacXxxGetContextSize(). As a part of that, we also
simplified the HMAC API -- note that Init was replaced by SetKey. And
because we were reworking an existent API, I didn't propose very
intrusive changes -- I didn't propose fusing Final and Free, for example.

Now, the EVP MD APIs are just being introduced to edk2. So we have a
chance at getting them right, and making them minimal.

Second, I believe EVP is just something in openssl. It does not mean that we
*have to* design API to follow
openssl.
After rethink the size impact, I do have concern to merge all Hash
implementation together in one function.
It might means nothing if the crypto library is based upon openssl.
But if the cryptolib implementation is based upon other crypto, such as Intel
IPP
(https://github.com/slimbootloader/slimbootloader/tree/master/BootloaderCo
mmonPkg/Library/IppCryptoLib) or mbedTls
(https://github.com/jyao1/edk2/tree/DeviceSecurity/CryptoMbedTlsPkg), then
we can NOT get size benefit by separating
the hash algorithm.


I would like to propose separate EvpMdxxx.
EvpMdNew -> Sha256New, Sha384New
EvpMdInit -> Sha256Init, Sha384Init
EvpMdUpdate -> Sha256Update, Sha384Update
EvpMdFinal -> Sha256Final, Sha384Final
EvpMdFree -> Sha256Free, Sha384Free
I have no comment on this.

We can do similar thing with Hmac, to deprecate Sha256GetContextSize()
API,

Yes, good idea.

and replace caller with Sha256New() / Sha384Free()
Indeed.

But then -- there's no reason left for keeping (New, Free) separate from
(Init, Final).

Thanks
Laszlo