Re: [PATCH v6 0/5] Use RngLib instead of TimerLib for OpensslLib


Matthew Carlson
 

I'll file a new bugzilla.


On Thu, Aug 13, 2020 at 8:15 AM Yao, Jiewen <jiewen.yao@...> wrote:
Thanks Matthew.

I am OK, if you want to address the RDSEED in follow-up patch series.

Would you please file a new Bugzilla to record this, so we won't lose the information ?



> -----Original Message-----
> From: matthewfcarlson@... <matthewfcarlson@...>
> Sent: Thursday, August 13, 2020 6:44 AM
> To: devel@edk2.groups.io
> Cc: Ard Biesheuvel <ard.biesheuvel@...>; Anthony Perard
> <anthony.perard@...>; Yao, Jiewen <jiewen.yao@...>; Wang,
> Jian J <jian.j.wang@...>; Julien Grall <julien@...>; Justen, Jordan L
> <jordan.l.justen@...>; Laszlo Ersek <lersek@...>; Gao, Liming
> <liming.gao@...>; Leif Lindholm <leif@...>; Kinney, Michael D
> <michael.d.kinney@...>; Lu, XiaoyuX <xiaoyux.lu@...>; Liu,
> Zhiguang <zhiguang.liu@...>; Sean Brogan
> <sean.brogan@...>; Matthew Carlson
> <matthewfcarlson@...>
> Subject: [PATCH v6 0/5] Use RngLib instead of TimerLib for OpensslLib
>
> From: Matthew Carlson <macarl@...>
>
> Hello all,
>
> This patch contains a fix for Bugzilla 1871.
> There's been a good bit of community discussion around the topic,
> so below follows a general overview of the discussion and what this patch does.
>
> Back in Devel message#40590 (https://edk2.groups.io/g/devel/message/40590)
> around the patch series that updates OpenSSL to 1.1.1b, a comment was made
> that suggested that platforms be in charge of the entropy/randomness that
> is provided to OpenSSL as currently the entropry source seems to be a
> hand-rolled random number generator that uses the PerformanceCounter from
> TimerLib. This causes OpenSSL to depend on TimerLib, which is often platform
> specific. In addition to being a potentially weaker source of randomness,
> this also poses a challenge to compile BaseCryptLibOnProtocol with a platform-
> agnostic version of TimerLib that works universally.
>
> The solution here is to allow platform to specify their source of entropy in
> addition to providing two new RngLibs: one that uses the TimerLib as well as
> one that uses RngProtocol to provide randomness. Then the decision to use
> RDRAND or other entropy sources is up to the platform. Mixing various entropy
> sources is the onus of the platform. It has been suggested on Devel#40590 and
> BZ#1871 that there should be mixing of the PerformanceCounter and RDRAND
> using
> something similar to the yarrow alogirthm that FreeBSD uses for example. This
> patch series doesn't offer an RngLib that offers that sort of mixing as the
> ultimate source of random is defined by the platform.
>
> This patch series offers three benefits:
> 1. Dependency reduction: Removes the need for a platform specific timer
> library.  We publish a single binary used on numerous platforms for
> crypto and the introduced timer lib dependency caused issues because we
> could not fulfill our platform needs with one library instance.
>
> 2. Code maintenance: Removing this additional code and leveraging an existing
> library within Edk2 means less code to maintain.
>
> 3. Platform defined quality: A platform can choose which instance to use and
> the implications of that instance.
>
> This patch series seeks to address five seperate issues.
>   1) Use RngLib interface to generate random entropy in rand_pool
>   2) Remove dependency on TimerLib in OpensslLib
>   3) Add a new version of RngLib implemented by TimerLib
>   4) Add a new version of RngLib implemented by EFI_RNG_PROTOCOL
>   5) Add RngLib to platforms in EDK2 such as ArmVirtPkg and OvmfPkg
>
> Since this changes the dependencies of OpenSSL, this has the potential of being
> a breaking change for platforms in edk2-platforms. The easiest solution is just
> to use the RngLib that uses the TimerLib as this closely mimics the behavior of
> OpenSSL prior to this patch series. There is also a null version of RngLib for
> CI environments that need this change
> (https://edk2.groups.io/g/devel/message/50432). Though it should be pointed
> out
> that in CI environments, the null version of BaseCryptLib or OpenSSL should be
> used.
>
> In addition, it has been suggested that
> 1) Add AsmRdSeed to BaseLib.
> 2) Update BaseRngLib to use AsmRdSeed() for the random number,
> if RdSeed is supported (CPUID BIT18)
>
> However, this is largely out of scope for this particular patch series and
> will likely need to be in a follow-up series later.
>
> It is my understanding that the OpenSSL code uses the values provided as a
> randomness pool rather than a seed or random numbers itself, so the
> requirements for randomness are not quite as stringent as other applications.
>
> For the ArmVirtPkg and OvmfPkg platforms, the patch series here just adds in
> the TimerLib based RngLib as that is similar to the functionality of before.
> It is added as a common library so any custom RngLib defined in the DSC
> should take precedence over the TimerLibRngLib.
>
> Ref: https://github.com/tianocore/edk2/pull/845
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1871
>
> Cc: Ard Biesheuvel <ard.biesheuvel@...>
> Cc: Anthony Perard <anthony.perard@...>
> Cc: Jiewen Yao <jiewen.yao@...>
> Cc: Jian J Wang <jian.j.wang@...>
> Cc: Julien Grall <julien@...>
> Cc: Jordan Justen <jordan.l.justen@...>
> Cc: Laszlo Ersek <lersek@...>
> Cc: Liming Gao <liming.gao@...>
> Cc: Leif Lindholm <leif@...>
> Cc: Michael D Kinney <michael.d.kinney@...>
> Cc: Xiaoyu Lu <xiaoyux.lu@...>
> Cc: Zhiguang Liu <zhiguang.liu@...>
> Cc: Sean Brogan <sean.brogan@...>
>
> Signed-off-by: Matthew Carlson <matthewfcarlson@...>
>
>
> Matthew Carlson (5):
>   MdePkg: TimerRngLib: Added RngLib that uses TimerLib
>   MdePkg: BaseRngLibDxe: Add RngLib that uses RngDxe
>   OvmfPkg: Add RngLib based on TimerLib for Crypto
>   ArmVirtPkg: Add RngLib based on TimerLib for CryptoPkg
>   CryptoPkg: OpensslLib: Use RngLib to generate entropy in rand_pool
>
>  CryptoPkg/Library/OpensslLib/rand_pool.c                 | 203 ++------------------
>  CryptoPkg/Library/OpensslLib/rand_pool_noise.c           |  29 ---
>  CryptoPkg/Library/OpensslLib/rand_pool_noise_tsc.c       |  43 -----
>  MdePkg/Library/BaseRngLibDxe/RngDxeLib.c                 | 200
> +++++++++++++++++++
>  MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c          | 187
> ++++++++++++++++++
>  ArmVirtPkg/ArmVirt.dsc.inc                               |   1 +
>  CryptoPkg/CryptoPkg.dsc                                  |   1 +
>  CryptoPkg/Library/OpensslLib/OpensslLib.inf              |  15 +-
>  CryptoPkg/Library/OpensslLib/OpensslLibCrypto.inf        |  15 +-
>  CryptoPkg/Library/OpensslLib/rand_pool_noise.h           |  29 ---
>  MdePkg/Library/BaseRngLibDxe/BaseRngLibDxe.inf           |  38 ++++
>  MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf |  40 ++++
>  MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni |  17 ++
>  MdePkg/MdePkg.dsc                                        |   5 +-
>  OvmfPkg/Bhyve/BhyvePkgX64.dsc                            |   1 +
>  OvmfPkg/OvmfPkgIa32.dsc                                  |   1 +
>  OvmfPkg/OvmfPkgIa32X64.dsc                               |   1 +
>  OvmfPkg/OvmfPkgX64.dsc                                   |   1 +
>  OvmfPkg/OvmfXen.dsc                                      |   1 +
>  19 files changed, 514 insertions(+), 314 deletions(-)
>  delete mode 100644 CryptoPkg/Library/OpensslLib/rand_pool_noise.c
>  delete mode 100644 CryptoPkg/Library/OpensslLib/rand_pool_noise_tsc.c
>  create mode 100644 MdePkg/Library/BaseRngLibDxe/RngDxeLib.c
>  create mode 100644 MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c
>  delete mode 100644 CryptoPkg/Library/OpensslLib/rand_pool_noise.h
>  create mode 100644 MdePkg/Library/BaseRngLibDxe/BaseRngLibDxe.inf
>  create mode 100644
> MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf
>  create mode 100644
> MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni
>
> --
> 2.27.0.windows.1

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