Re: [edk2-devel] [PATCH v2] MdePkg: add null version of RngLib

["Laszlo Ersek" <lersek@redhat.com>]

On 11/13/19 09:43, Wang, Jian J wrote:
> As requested by Ray, I'd like to mention more usage about this library
> instance.
> 
> To be more specific, if following components or functionalities are used in a
> platform, the BaseRngLibNull should *not* be used. Instead, a non-Null version
> of RngLib must be used (like BaseRngLib for IA32/X64, or coming RngDxeLib
> for all ARCHs).
> 
> - SecurityPkg/HddPassword/HddPasswordDxe.c
> - AES, TLS (NetworkPkg/TlsDxe/TlsDxe.inf, CryptoPkg/Library/TlsLib/TlsLib.inf)
>   RSA_OAEP, RSA_PK1
> - (If BaseRngLibNull interface ASSERTed at boot time)

Just a naming suggestion for "RngDxeLib": I think it should be called
"DxeRngLibXxxx", where "Xxxx" should stand for the core idea in the
implementation. For example, if the library is based on
EFI_RNG_PROTOCOL, then it likely should be called

  DxeRngLibRngProtocol

This scheme seems consistent with some other library instance names
under MdePkg/Library:

  MdePkg/Library/UefiDebugLibDebugPortProtocol
  MdePkg/Library/UefiDevicePathLibDevicePathProtocol

and maybe even with

  MdePkg/Library/SmmPciLibPciRootBridgeIo
  MdePkg/Library/UefiPciLibPciRootBridgeIo

Thanks
Laszlo

> 
> Regards,
> Jian
> 
>> -----Original Message-----
>> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Wang, Jian
>> J
>> Sent: Wednesday, November 13, 2019 1:35 PM
>> To: devel@edk2.groups.io
>> Cc: Kinney, Michael D <michael.d.kinney@intel.com>; Gao, Liming
>> <liming.gao@intel.com>; Laszlo Ersek <lersek@redhat.com>; Ard Biesheuvel
>> <ard.biesheuvel@linaro.org>; Ni, Ray <ray.ni@intel.com>
>> Subject: [edk2-devel] [PATCH v2] MdePkg: add null version of RngLib
>>
>>> v2:
>>>  - Change the name from RngLibNull to BaseRngLibNull according to Laszlo's
>>>    comments
>>>  - Move the module from SecurityPkg to MdePkg according to Laszlo's
>> comments
>>>  - Update commit message according to Laszlo and Ray's comments
>>
>> This is null version of RngLib which should be used with modules that
>> inherit an (indirect) dependency on the RngLib class, but never actually
>> call RngLib APIs for consuming randomness.
>>
>>
>> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1871
>> Cc: Michael D Kinney <michael.d.kinney@intel.com>
>> Cc: Liming Gao <liming.gao@intel.com>
>> Cc: Laszlo Ersek <lersek@redhat.com>
>> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> Cc: Ray Ni <ray.ni@intel.com>
>> Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
>> ---
>>  .../Library/BaseRngLibNull/BaseRngLibNull.c   | 95 +++++++++++++++++++
>>  .../Library/BaseRngLibNull/BaseRngLibNull.inf | 31 ++++++
>>  .../Library/BaseRngLibNull/BaseRngLibNull.uni | 14 +++
>>  MdePkg/MdePkg.dsc                             |  1 +
>>  4 files changed, 141 insertions(+)
>>  create mode 100644 MdePkg/Library/BaseRngLibNull/BaseRngLibNull.c
>>  create mode 100644 MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
>>  create mode 100644 MdePkg/Library/BaseRngLibNull/BaseRngLibNull.uni
>>
>> diff --git a/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.c
>> b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.c
>> new file mode 100644
>> index 0000000000..13677abc84
>> --- /dev/null
>> +++ b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.c
>> @@ -0,0 +1,95 @@
>> +/** @file
>> +  Null version of Random number generator services.
>> +
>> +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>
>> +
>> +/**
>> +  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
>> +  )
>> +{
>> +  ASSERT (FALSE);
>> +  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
>> +  )
>> +{
>> +  ASSERT (FALSE);
>> +  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
>> +  )
>> +{
>> +  ASSERT (FALSE);
>> +  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 (FALSE);
>> +  return FALSE;
>> +}
>> diff --git a/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
>> b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
>> new file mode 100644
>> index 0000000000..f456df1dae
>> --- /dev/null
>> +++ b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
>> @@ -0,0 +1,31 @@
>> +## @file
>> +#  Null instance of RNG (Random Number Generator) Library.
>> +#
>> +#  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>> +#
>> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +#
>> +##
>> +
>> +[Defines]
>> +  INF_VERSION                    = 0x00010005
>> +  BASE_NAME                      = BaseRngLibNull
>> +  MODULE_UNI_FILE                = BaseRngLibNull.uni
>> +  FILE_GUID                      = CD8991F8-2061-4084-8C9E-9C6F352DC58D
>> +  MODULE_TYPE                    = BASE
>> +  VERSION_STRING                 = 1.0
>> +  LIBRARY_CLASS                  = RngLib
>> +
>> +#
>> +#  VALID_ARCHITECTURES           = IA32 X64 ARM AARCH64
>> +#
>> +
>> +[Sources]
>> +  BaseRngLibNull.c
>> +
>> +[Packages]
>> +  MdePkg/MdePkg.dec
>> +
>> +[LibraryClasses]
>> +  BaseLib
>> +  DebugLib
>> diff --git a/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.uni
>> b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.uni
>> new file mode 100644
>> index 0000000000..f32be6a617
>> --- /dev/null
>> +++ b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.uni
>> @@ -0,0 +1,14 @@
>> +// /** @file
>> +// Null Instance of RNG (Random Number Generator) Library.
>> +//
>> +// Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>> +//
>> +// SPDX-License-Identifier: BSD-2-Clause-Patent
>> +//
>> +// **/
>> +
>> +
>> +#string STR_MODULE_ABSTRACT             #language en-US "Null Instance of
>> RNG Library"
>> +
>> +#string STR_MODULE_DESCRIPTION          #language en-US "This library
>> instance should be used with modules that inherit an (indirect) dependency on
>> the RngLib class, but never actually call RngLib APIs for consuming randomness."
>> +
>> diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
>> index c1278e7907..0aeafaaacc 100644
>> --- a/MdePkg/MdePkg.dsc
>> +++ b/MdePkg/MdePkg.dsc
>> @@ -61,6 +61,7 @@
>>
>> MdePkg/Library/BaseUefiDecompressLib/BaseUefiTianoCustomDecompressLib.
>> inf
>>    MdePkg/Library/BaseSmbusLibNull/BaseSmbusLibNull.inf
>>    MdePkg/Library/BaseSafeIntLib/BaseSafeIntLib.inf
>> +  MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
>>
>>    MdePkg/Library/DxeCoreEntryPoint/DxeCoreEntryPoint.inf
>>    MdePkg/Library/DxeCoreHobLib/DxeCoreHobLib.inf
>> --
>> 2.17.1.windows.2
>>
>>
>> 
>