Re: [edk2-devel] [PATCH 05/11] SecurityPkg/RngLibRdSeed: add an instance of RngLib to make use rdseed

["Michael D Kinney" <michael.d.kinney@intel.com>]

Hi Ard,

What would you recommend as way to provide these different
types of services?  Some more new lib classes and instances?

Thanks,

Mike

> -----Original Message-----
> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Sent: Friday, November 15, 2019 5:29 AM
> To: edk2-devel-groups-io <devel@edk2.groups.io>; Wang,
> Jian J <jian.j.wang@intel.com>
> Cc: Kinney, Michael D <michael.d.kinney@intel.com>;
> Yao, Jiewen <jiewen.yao@intel.com>; Zhang, Chao B
> <chao.b.zhang@intel.com>; Gao, Liming
> <liming.gao@intel.com>; Ni, Ray <ray.ni@intel.com>
> Subject: Re: [edk2-devel] [PATCH 05/11]
> SecurityPkg/RngLibRdSeed: add an instance of RngLib to
> make use rdseed
> 
> On Thu, 14 Nov 2019 at 04:39, Wang, Jian J
> <jian.j.wang@intel.com> wrote:
> >
> > Mike,
> >
> > I figured that rdseed is only needed in cases
> demanding highest
> > entropy, like seeding other pseudo-RNG. It's not for
> general purpose randomness.
> > Then I put it in SecurityPkg. But I'm ok to put it
> into MdePkg. I have
> > no strong opinion for this.
> >
> 
> I think it is a bad idea to use the same library
> abstraction [RngLib] for exposing
> a) entropy sources used for seeding deterministic
> random number generators
> b) deterministic random number generators themselves
> c) low entropy pseudo-RNGs based on timestamp counters,
> etc
> 
> given that the use cases don't usually overlap. I.e.,
> only a DRBG implementation requires a), and exports
> RngLib itself based on that.
> Use cases that can tolerate c) [like IV generators for
> block encryption] are typically disjoint from ones that
> require b) [for key generation]. The idea that you can
> use RngLib for all of them, and plug arbitrary
> instantiations of it into each is misguided IMHO.
> 
> 
> 
> > > -----Original Message-----
> > > From: Kinney, Michael D
> <michael.d.kinney@intel.com>
> > > Sent: Thursday, November 14, 2019 12:25 PM
> > > To: devel@edk2.groups.io; Wang, Jian J
> <jian.j.wang@intel.com>;
> > > Kinney, Michael D <michael.d.kinney@intel.com>
> > > Cc: Yao, Jiewen <jiewen.yao@intel.com>; Zhang, Chao
> B
> > > <chao.b.zhang@intel.com>; Gao, Liming
> <liming.gao@intel.com>; Ni,
> > > Ray <ray.ni@intel.com>
> > > Subject: RE: [edk2-devel] [PATCH 05/11]
> SecurityPkg/RngLibRdSeed:
> > > add an instance of RngLib to make use rdseed
> > >
> > > Jian,
> > >
> > > Why is this lib instance in the SecurityPkg?  It
> only depends on the
> > > MdePkg.  Can't non security feature related modules
> that want to a
> > > random number use this lib without using the
> SecurityPkg?  Could
> > > this lib instance be added to MdePkg?
> > >
> > > Thanks,
> > >
> > > Mike
> > >
> > > > -----Original Message-----
> > > > From: devel@edk2.groups.io <devel@edk2.groups.io>
> On Behalf Of
> > > > Wang, Jian J
> > > > Sent: Wednesday, November 13, 2019 6:18 PM
> > > > To: devel@edk2.groups.io
> > > > Cc: Yao, Jiewen <jiewen.yao@intel.com>; Zhang,
> Chao B
> > > > <chao.b.zhang@intel.com>; Kinney, Michael D
> > > > <michael.d.kinney@intel.com>; Gao, Liming
> <liming.gao@intel.com>;
> > > > Ni, Ray <ray.ni@intel.com>
> > > > Subject: [edk2-devel] [PATCH 05/11]
> > > > SecurityPkg/RngLibRdSeed: add an instance of
> RngLib to make use
> > > > rdseed
> > > >
> > > > This version of RngLib makes use of AsmRdSeed to
> get
> > > > non-deterministic random number, which can be
> used for seeding
> > > > other software DRNG like rand interface in
> openssl. It can be used
> > > > only on IA32/X64 processors which supports rdseed
> instruction.
> > > >
> > > > Ref:
> > > >
> https://bugzilla.tianocore.org/show_bug.cgi?id=1871
> > > > Cc: Jiewen Yao <jiewen.yao@intel.com>
> > > > Cc: Chao Zhang <chao.b.zhang@intel.com>
> > > > Cc: Michael D Kinney <michael.d.kinney@intel.com>
> > > > Cc: Liming Gao <liming.gao@intel.com>
> > > > Cc: Ray Ni <ray.ni@intel.com>
> > > > Signed-off-by: Jian J Wang
> <jian.j.wang@intel.com>
> > > > ---
> > > >  .../RngLibRdSeed/RngLibRdSeed.inf             |
> 37
> > > > ++++
> > > >  .../RngLibRdSeed/RngLibRdSeed.uni             |
> 18 ++
> > > >  .../RngLibRdSeed/RngRdSeed.c                  |
> 189
> > > > ++++++++++++++++++
> > > >  3 files changed, 244 insertions(+)  create mode
> 100644
> > > >
> SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngLibRd
> > > > Seed.inf
> > > >  create mode 100644
> > > >
> SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngLibRd
> > > > Seed.uni
> > > >  create mode 100644
> > > >
> SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngRdSee
> > > > d.c
> > > >
> > > > diff --git
> > > >
> a/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngLib
> > > > RdSeed.inf
> > > >
> b/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngLib
> > > > RdSeed.inf
> > > > new file mode 100644
> > > > index 0000000000..8162408775
> > > > --- /dev/null
> > > > +++
> > > >
> b/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngLib
> > > > RdSeed.inf
> > > > @@ -0,0 +1,37 @@
> > > > +## @file
> > > > +#  Instance of RNG (Random Number Generator)
> Library.
> > > > +#
> > > > +#  Rng RdSeed Library that uses CPU RdSeed
> instruction
> > > > access to
> > > > +provide #  non-deterministic random number which
> can
> > > > be used as seed
> > > > +for other #  software deterministic RNGs.
> > > > +#
> > > > +#  Copyright (c) 2019, Intel Corporation. All
> rights
> > > > reserved.<BR> # #
> > > > +SPDX-License-Identifier: BSD-2-Clause-Patent # #
> ##
> > > > +
> > > > +[Defines]
> > > > +  INF_VERSION                    = 0x00010029
> > > > +  BASE_NAME                      = RngLibRdSeed
> > > > +  MODULE_UNI_FILE                =
> RngLibRdSeed.uni
> > > > +  FILE_GUID                      = 8B613B2E-
> B944-40F9-
> > > > B979-1B60D7CAA73C
> > > > +  MODULE_TYPE                    = BASE
> > > > +  VERSION_STRING                 = 1.0
> > > > +  LIBRARY_CLASS                  = RngLib
> > > > +  CONSTRUCTOR                    =
> > > > RngLibRdSeedConstructor
> > > > +
> > > > +#
> > > > +#  VALID_ARCHITECTURES           = IA32 X64
> > > > +#
> > > > +
> > > > +[Sources.Ia32, Sources.X64]
> > > > +  RngRdSeed.c
> > > > +
> > > > +[Packages]
> > > > +  MdePkg/MdePkg.dec
> > > > +
> > > > +[LibraryClasses]
> > > > +  BaseLib
> > > > +  DebugLib
> > > > diff --git
> > > >
> a/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngLib
> > > > RdSeed.uni
> > > >
> b/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngLib
> > > > RdSeed.uni
> > > > new file mode 100644
> > > > index 0000000000..051a3019bc
> > > > --- /dev/null
> > > > +++
> > > >
> b/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngLib
> > > > RdSeed.uni
> > > > @@ -0,0 +1,18 @@
> > > > +// /** @file
> > > > +// Instance of RNG (Random Number Generator)
> Library.
> > > > +//
> > > > +// Rng RdSeed Library that uses CPU RdSeed
> instruction
> > > > access to
> > > > +provide // non-deterministic random number which
> can
> > > > be used as seed
> > > > +for other // software deterministic RNGs.
> > > > +//
> > > > +// Copyright (c) 2019, Intel Corporation. All
> rights
> > > > reserved.<BR> //
> > > > +// SPDX-License-Identifier: BSD-2-Clause-Patent
> // //
> > > > **/
> > > > +
> > > > +
> > > > +#string STR_MODULE_ABSTRACT
> #language en-
> > > > US "Instance of RNG Library"
> > > > +
> > > > +#string STR_MODULE_DESCRIPTION
> #language en-
> > > > US "RngRdSeed Library that uses CPU RdSeed
> instruction access to
> > > > provide non-deterministic random numbers."
> > > > +
> > > > diff --git
> > > >
> a/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngRdS
> > > > eed.c
> > > >
> b/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngRdS
> > > > eed.c
> > > > new file mode 100644
> > > > index 0000000000..0036faa050
> > > > --- /dev/null
> > > > +++
> > > >
> b/SecurityPkg/RandomNumberGenerator/RngLibRdSeed/RngRdS
> > > > eed.c
> > > > @@ -0,0 +1,189 @@
> > > > +/** @file
> > > > +  Random number generator services that uses
> RdSeed
> > > > instruction access
> > > > +  to provide non-deterministic random numbers,
> which
> > > > are usually used
> > > > +  for seeding other pseudo-random number
> generators.
> > > > +
> > > > +Copyright (c) 2019, Intel Corporation. All
> rights
> > > > reserved.<BR>
> > > > +SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > +
> > > > +**/
> > > > +
> > > > +#include <Library/BaseLib.h>
> > > > +#include <Library/DebugLib.h>
> > > > +#include <Library/RngLib.h>
> > > > +
> > > > +//
> > > > +// Bit mask used to determine if RdSeed
> instruction is
> > > > supported.
> > > > +//
> > > > +#define RDSEED_MASK                  BIT18
> > > > +
> > > > +//
> > > > +// Limited retry number when valid random data
> is
> > > > returned.
> > > > +// It varies between 1 and 100 according to
> "Intel(R)
> > > > DRGN Software
> > > > +Implementation // Guide". Let's use the same
> value as
> > > > RDRAND in BaseRngLib.
> > > > +//
> > > > +#define RDSEED_RETRY_LIMIT           10
> > > > +
> > > > +/**
> > > > +  The constructor function checks whether or not
> > > > RDSEED instruction is
> > > > +supported
> > > > +  by the host hardware.
> > > > +
> > > > +  The constructor function checks whether or not
> > > > RDSEED instruction is supported.
> > > > +  It will ASSERT() if RDSEED instruction is not
> > > > supported.
> > > > +
> > > > +  @retval RETURN_SUCCESS      The processor
> supports
> > > > RDSEED instruction.
> > > > +  @retval RETURN_UNSUPPORTED  RDSEED instruction
> is
> > > > not supported.
> > > > +
> > > > +**/
> > > > +RETURN_STATUS
> > > > +EFIAPI
> > > > +RngLibRdSeedConstructor (
> > > > +  VOID
> > > > +  )
> > > > +{
> > > > +  UINT32  RegEbx;
> > > > +
> > > > +  //
> > > > +  // Determine RDSEED support by examining bit
> 18 of
> > > > the EBX register
> > > > + returned by  // CPUID(EAX=7, ECX=0). BIT18 of
> EBX
> > > > indicates that
> > > > + processor support RDSEED  // instruction.
> > > > +  //
> > > > +  AsmCpuidEx (7, 0, NULL, &RegEbx, NULL, NULL);
> if
> > > > ((RegEbx &
> > > > + RDSEED_MASK) != RDSEED_MASK) {
> > > > +    ASSERT ((RegEbx & RDSEED_MASK) ==
> RDSEED_MASK);
> > > > +    return RETURN_UNSUPPORTED;
> > > > +  }
> > > > +
> > > > +  return RETURN_SUCCESS;
> > > > +}
> > > > +
> > > > +/**
> > > > +  Generates a 16-bit random number.
> > > > +
> > > > +  if Rand is NULL, then ASSERT().
> > > > +
> > > > +  @param[out] Rand     Buffer pointer to store
> the 16-
> > > > bit random value.
> > > > +
> > > > +  @retval TRUE         Random number generated
> > > > successfully.
> > > > +  @retval FALSE        Failed to generate the
> random
> > > > number.
> > > > +
> > > > +**/
> > > > +BOOLEAN
> > > > +EFIAPI
> > > > +GetRandomNumber16 (
> > > > +  OUT     UINT16                    *Rand
> > > > +  )
> > > > +{
> > > > +  UINT32  Index;
> > > > +
> > > > +  ASSERT (Rand != NULL);
> > > > +
> > > > +  //
> > > > +  // A loop to fetch a 16 bit random value with
> a
> > > > retry count limit.
> > > > +  //
> > > > +  for (Index = 0; Index < RDSEED_RETRY_LIMIT;
> Index++)
> > > > {
> > > > +    if (AsmRdSeed16 (Rand)) {
> > > > +      return TRUE;
> > > > +    }
> > > > +  }
> > > > +
> > > > +  return FALSE;
> > > > +}
> > > > +
> > > > +/**
> > > > +  Generates a 32-bit random number.
> > > > +
> > > > +  if Rand is NULL, then ASSERT().
> > > > +
> > > > +  @param[out] Rand     Buffer pointer to store
> the 32-
> > > > bit random value.
> > > > +
> > > > +  @retval TRUE         Random number generated
> > > > successfully.
> > > > +  @retval FALSE        Failed to generate the
> random
> > > > number.
> > > > +
> > > > +**/
> > > > +BOOLEAN
> > > > +EFIAPI
> > > > +GetRandomNumber32 (
> > > > +  OUT     UINT32                    *Rand
> > > > +  )
> > > > +{
> > > > +  UINT32  Index;
> > > > +
> > > > +  ASSERT (Rand != NULL);
> > > > +
> > > > +  //
> > > > +  // A loop to fetch a 32 bit random value with
> a
> > > > retry count limit.
> > > > +  //
> > > > +  for (Index = 0; Index < RDSEED_RETRY_LIMIT;
> Index++)
> > > > {
> > > > +    if (AsmRdSeed32 (Rand)) {
> > > > +      return TRUE;
> > > > +    }
> > > > +  }
> > > > +
> > > > +  return FALSE;
> > > > +}
> > > > +
> > > > +/**
> > > > +  Generates a 64-bit random number.
> > > > +
> > > > +  if Rand is NULL, then ASSERT().
> > > > +
> > > > +  @param[out] Rand     Buffer pointer to store
> the 64-
> > > > bit random value.
> > > > +
> > > > +  @retval TRUE         Random number generated
> > > > successfully.
> > > > +  @retval FALSE        Failed to generate the
> random
> > > > number.
> > > > +
> > > > +**/
> > > > +BOOLEAN
> > > > +EFIAPI
> > > > +GetRandomNumber64 (
> > > > +  OUT     UINT64                    *Rand
> > > > +  )
> > > > +{
> > > > +  UINT32  Index;
> > > > +
> > > > +  ASSERT (Rand != NULL);
> > > > +
> > > > +  //
> > > > +  // A loop to fetch a 64 bit random value with
> a
> > > > retry count limit.
> > > > +  //
> > > > +  for (Index = 0; Index < RDSEED_RETRY_LIMIT;
> Index++)
> > > > {
> > > > +    if (AsmRdSeed64 (Rand)) {
> > > > +      return TRUE;
> > > > +    }
> > > > +  }
> > > > +
> > > > +  return FALSE;
> > > > +}
> > > > +
> > > > +/**
> > > > +  Generates a 128-bit random number.
> > > > +
> > > > +  if Rand is NULL, then ASSERT().
> > > > +
> > > > +  @param[out] Rand     Buffer pointer to store
> the
> > > > 128-bit random value.
> > > > +
> > > > +  @retval TRUE         Random number generated
> > > > successfully.
> > > > +  @retval FALSE        Failed to generate the
> random
> > > > number.
> > > > +
> > > > +**/
> > > > +BOOLEAN
> > > > +EFIAPI
> > > > +GetRandomNumber128 (
> > > > +  OUT     UINT64                    *Rand
> > > > +  )
> > > > +{
> > > > +  ASSERT (Rand != NULL);
> > > > +
> > > > +  //
> > > > +  // Read first 64 bits
> > > > +  //
> > > > +  if (!GetRandomNumber64 (Rand)) {
> > > > +    return FALSE;
> > > > +  }
> > > > +
> > > > +  //
> > > > +  // Read second 64 bits
> > > > +  //
> > > > +  return GetRandomNumber64 (++Rand); }
> > > > --
> > > > 2.17.1.windows.2
> > > >
> > > >
> > > >
> >
> >
> > 
> >