[edk2-devel] [PATCH v4 06/21] MdePkg/TrngLib: Add NULL instance of TRNG Library
PierreGondois
pierre.gondois at arm.com
Fri Jul 22 14:31:38 UTC 2022
From: Sami Mujawar <sami.mujawar at arm.com>
Bugzilla: 3668 (https://bugzilla.tianocore.org/show_bug.cgi?id=3668)
The True Random Number Generator (TRNG) library defines an
interface to access the entropy source on a platform. On
platforms that do not have access to an entropy source, a
NULL instance of the TRNG library may be useful to satisfy
the build dependency.
Therefore, add a NULL instance of the TRNG library.
Signed-off-by: Sami Mujawar <sami.mujawar at arm.com>
---
.../Library/BaseTrngLibNull/BaseTrngLibNull.c | 135 ++++++++++++++++++
.../BaseTrngLibNull/BaseTrngLibNull.inf | 30 ++++
.../BaseTrngLibNull/BaseTrngLibNull.uni | 12 ++
MdePkg/MdePkg.dsc | 1 +
4 files changed, 178 insertions(+)
create mode 100644 MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.c
create mode 100644 MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.inf
create mode 100644 MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.uni
diff --git a/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.c b/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.c
new file mode 100644
index 000000000000..e383cd0cf1cc
--- /dev/null
+++ b/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.c
@@ -0,0 +1,135 @@
+/** @file
+ Null version of TRNG (True Random Number Generator) services.
+
+ Copyright (c) 2021 - 2022, Arm Limited. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+ @par Reference(s):
+ - [1] Arm True Random Number Generator Firmware, Interface 1.0,
+ Platform Design Document.
+ (https://developer.arm.com/documentation/den0098/latest/)
+ - [2] NIST Special Publication 800-90A Revision 1, June 2015, Recommendation
+ for Random Number Generation Using Deterministic Random Bit Generators.
+ (https://csrc.nist.gov/publications/detail/sp/800-90a/rev-1/final)
+ - [3] NIST Special Publication 800-90B, Recommendation for the Entropy
+ Sources Used for Random Bit Generation.
+ (https://csrc.nist.gov/publications/detail/sp/800-90b/final)
+ - [4] (Second Draft) NIST Special Publication 800-90C, Recommendation for
+ Random Bit Generator (RBG) Constructions.
+ (https://csrc.nist.gov/publications/detail/sp/800-90c/draft)
+
+ @par Glossary:
+ - TRNG - True Random Number Generator
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/TrngLib.h>
+
+/** Get the version of the TRNG backend.
+
+ A TRNG may be implemented by the system firmware, in which case this
+ function shall return the version of the TRNG backend.
+ The implementation must return NOT_SUPPORTED if a Back end is not present.
+
+ @param [out] MajorRevision Major revision.
+ @param [out] MinorRevision Minor revision.
+
+ @retval RETURN_SUCCESS The function completed successfully.
+ @retval RETURN_INVALID_PARAMETER Invalid parameter.
+ @retval RETURN_UNSUPPORTED Backend not present.
+**/
+RETURN_STATUS
+EFIAPI
+GetTrngVersion (
+ OUT UINT16 *MajorRevision,
+ OUT UINT16 *MinorRevision
+ )
+{
+ ASSERT (FALSE);
+ return RETURN_UNSUPPORTED;
+}
+
+/** Get the UUID of the TRNG backend.
+
+ A TRNG may be implemented by the system firmware, in which case this
+ function shall return the UUID of the TRNG backend.
+ Returning the TRNG UUID is optional and if not implemented, RETURN_UNSUPPORTED
+ shall be returned.
+
+ Note: The caller must not rely on the returned UUID as a trustworthy TRNG
+ Back end identity
+
+ @param [out] Guid UUID of the TRNG backend.
+
+ @retval RETURN_SUCCESS The function completed successfully.
+ @retval RETURN_INVALID_PARAMETER Invalid parameter.
+ @retval RETURN_UNSUPPORTED Function not implemented.
+**/
+RETURN_STATUS
+EFIAPI
+GetTrngUuid (
+ OUT GUID *Guid
+ )
+{
+ ASSERT (FALSE);
+ return RETURN_UNSUPPORTED;
+}
+
+/** Returns maximum number of entropy bits that can be returned in a single
+ call.
+
+ @return Returns the maximum number of Entropy bits that can be returned
+ in a single call to GetTrngEntropy().
+**/
+UINTN
+EFIAPI
+GetTrngMaxSupportedEntropyBits (
+ VOID
+ )
+{
+ ASSERT (FALSE);
+ return 0;
+}
+
+/** Returns N bits of conditioned entropy.
+
+ See [3] Section 2.3.1 GetEntropy: An Interface to the Entropy Source
+ GetEntropy
+ Input:
+ bits_of_entropy: the requested amount of entropy
+ Output:
+ entropy_bitstring: The string that provides the requested entropy.
+ status: A Boolean value that is TRUE if the request has been satisfied,
+ and is FALSE otherwise.
+
+ Note: In this implementation this function returns a status code instead
+ of a boolean value.
+ This is also compatible with the definition of Get_Entropy, see [4]
+ Section 7.4 Entropy Source Calls.
+ (status, entropy_bitstring) = Get_Entropy (
+ requested_entropy,
+ max_length
+ )
+
+ @param [in] EntropyBits Number of entropy bits requested.
+ @param [in] BufferSize Size of the Buffer in bytes.
+ @param [out] Buffer Buffer to return the entropy bits.
+
+ @retval RETURN_SUCCESS The function completed successfully.
+ @retval RETURN_INVALID_PARAMETER Invalid parameter.
+ @retval RETURN_UNSUPPORTED Function not implemented.
+ @retval RETURN_BAD_BUFFER_SIZE Buffer size is too small.
+ @retval RETURN_NOT_READY No Entropy available.
+**/
+RETURN_STATUS
+EFIAPI
+GetTrngEntropy (
+ IN UINTN EntropyBits,
+ IN UINTN BufferSize,
+ OUT UINT8 *Buffer
+ )
+{
+ ASSERT (FALSE);
+ return RETURN_UNSUPPORTED;
+}
diff --git a/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.inf b/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.inf
new file mode 100644
index 000000000000..004aa8445a25
--- /dev/null
+++ b/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.inf
@@ -0,0 +1,30 @@
+## @file
+# Null instance of TRNG (True Random Number Generator) Library.
+#
+# Copyright (c) 2021 - 2022, Arm Limited. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x0001001B
+ BASE_NAME = BaseTrngLibNull
+ MODULE_UNI_FILE = BaseTrngLibNull.uni
+ FILE_GUID = ABDE1C87-4F50-4B82-9133-7A79E13F69AB
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = TrngLib
+
+#
+# VALID_ARCHITECTURES = IA32 X64 ARM AARCH64
+#
+
+[Sources]
+ BaseTrngLibNull.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ DebugLib
diff --git a/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.uni b/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.uni
new file mode 100644
index 000000000000..952e4354c0cc
--- /dev/null
+++ b/MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.uni
@@ -0,0 +1,12 @@
+// /** @file
+// Null Instance of TRNG (True Random Number Generator) Library.
+//
+// Copyright (c) 2021 - 2022, Arm Limited. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+#string STR_MODULE_ABSTRACT #language en-US "Null instance of TRNG Library"
+
+#string STR_MODULE_DESCRIPTION #language en-US "This library instance should be used with modules that inherit an (indirect) dependency on the TrngLib class, but never actually call TrngLib APIs for consuming Entropy."
diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
index 3d8874e64782..80e7233363d3 100644
--- a/MdePkg/MdePkg.dsc
+++ b/MdePkg/MdePkg.dsc
@@ -67,6 +67,7 @@ [Components]
MdePkg/Library/DxeRngLib/DxeRngLib.inf
MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf
+ MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.inf
MdePkg/Library/BaseSerialPortLibNull/BaseSerialPortLibNull.inf
MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
--
2.25.1
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