[PATCH v2 1/1] CryptoPkg: BaseCryptLib: Add RSA PSS verify support

["Agrawal, Sachin" <sachin.agrawal@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3314

This patch uses Openssl's EVP API's to perform RSASSA-PSS verification
of a binary blob.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Xiaoyu Lu <xiaoyux.lu@intel.com>
Cc: Guomin Jiang <guomin.jiang@intel.com>

Signed-off-by: Sachin Agrawal <sachin.agrawal@intel.com>
---

Notes:
    v2:
    - Added SaltLen as argument (Jiewen)
    - Added RsaPssSign support (Jiewen)
    - Added Unit test (Jiewen)
    - Added RSA PSS API in EDK2 Crypto Protocol (Missed in v1)

 CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c                        | 145 +++++++++++++++
 CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssNull.c                    |  46 +++++
 CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c                    | 168 +++++++++++++++++
 CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSignNull.c                |  60 ++++++
 CryptoPkg/Library/BaseCryptLibNull/Pk/CryptRsaPssNull.c                |  46 +++++
 CryptoPkg/Library/BaseCryptLibNull/Pk/CryptRsaPssSignNull.c            |  60 ++++++
 CryptoPkg/Library/BaseCryptLibOnProtocolPpi/CryptLib.c                 |  66 +++++++
 CryptoPkg/Test/UnitTest/Library/BaseCryptLib/BaseCryptLibUnitTests.c   |   1 +
 CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaPssTests.c             | 191 ++++++++++++++++++++
 CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaTests.c                |   2 +
 CryptoPkg/Include/Library/BaseCryptLib.h                               |  74 ++++++++
 CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf                        |   2 +
 CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf                         |   2 +
 CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf                     |   2 +
 CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf                         |   2 +
 CryptoPkg/Library/BaseCryptLib/UnitTestHostBaseCryptLib.inf            |   2 +
 CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf                |   2 +
 CryptoPkg/Private/Protocol/Crypto.h                                    |  78 ++++++++
 CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLib.h        |   3 +
 CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibHost.inf  |   1 +
 CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibShell.inf |   1 +
 21 files changed, 954 insertions(+)

diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c
new file mode 100644
index 000000000000..023f64ba214b
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c
@@ -0,0 +1,145 @@
+/** @file
+  RSA Asymmetric Cipher Wrapper Implementation over OpenSSL.
+
+  This file implements following APIs which provide basic capabilities for RSA:
+  1) RsaPssVerify
+
+Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
+#include <openssl/objects.h>
+#include <openssl/evp.h>
+
+
+/**
+  Retrieve a pointer to EVP message digest object.
+
+  @param[in]  DigestLen   Length of the message digest.
+
+**/
+static
+EVP_MD*
+GetEvpMD (
+  IN UINT16 DigestLen
+  )
+{
+  switch (DigestLen){
+    case SHA256_DIGEST_SIZE:
+      return EVP_sha256();
+      break;
+    case SHA384_DIGEST_SIZE:
+      return EVP_sha384();
+      break;
+    case SHA512_DIGEST_SIZE:
+      return EVP_sha512();
+      break;
+    default:
+      return NULL;
+  }
+}
+
+
+/**
+  Verifies the RSA signature with RSASSA-PSS signature scheme defined in RFC 8017.
+  Implementation determines salt length automatically from the signature encoding.
+  Mask generation function is the same as the message digest algorithm.
+  Salt length should atleast be equal to digest length.
+
+  @param[in]  RsaContext      Pointer to RSA context for signature verification.
+  @param[in]  Message         Pointer to octet message to be verified.
+  @param[in]  MsgSize         Size of the message in bytes.
+  @param[in]  Signature       Pointer to RSASSA-PSS signature to be verified.
+  @param[in]  SigSize         Size of signature in bytes.
+  @param[in]  DigestLen       Length of digest for RSA operation.
+  @param[in]  SaltLen         Salt length for PSS encoding.
+
+  @retval  TRUE   Valid signature encoded in RSASSA-PSS.
+  @retval  FALSE  Invalid signature or invalid RSA context.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssVerify (
+  IN  VOID         *RsaContext,
+  IN  CONST UINT8  *Message,
+  IN  UINTN        MsgSize,
+  IN  CONST UINT8  *Signature,
+  IN  UINTN        SigSize,
+  IN  UINT16       DigestLen,
+  IN  UINT16       SaltLen
+  )
+{
+  BOOLEAN Result;
+  EVP_PKEY *pEvpRsaKey = NULL;
+  EVP_MD_CTX *pEvpVerifyCtx = NULL;
+  EVP_PKEY_CTX *pKeyCtx = NULL;
+  CONST EVP_MD  *HashAlg = NULL;
+
+  if (RsaContext == NULL) {
+    return FALSE;
+  }
+  if (Message == NULL || MsgSize == 0 || MsgSize > INT_MAX) {
+    return FALSE;
+  }
+  if (Signature == NULL || SigSize == 0 || SigSize > INT_MAX) {
+    return FALSE;
+  }
+  if (SaltLen < DigestLen) {
+    return FALSE;
+  }
+
+  HashAlg = GetEvpMD(DigestLen);
+
+  if (HashAlg == NULL) {
+    return FALSE;
+  }
+
+  pEvpRsaKey = EVP_PKEY_new();
+  if (pEvpRsaKey == NULL) {
+    goto _Exit;
+  }
+
+  EVP_PKEY_set1_RSA(pEvpRsaKey, RsaContext);
+
+  pEvpVerifyCtx = EVP_MD_CTX_create();
+  if (pEvpVerifyCtx == NULL) {
+    goto _Exit;
+  }
+
+  Result = EVP_DigestVerifyInit(pEvpVerifyCtx, &pKeyCtx, HashAlg, NULL, pEvpRsaKey) > 0;
+  if (pKeyCtx == NULL) {
+    goto _Exit;
+  }
+
+  if (Result) {
+    Result = EVP_PKEY_CTX_set_rsa_padding(pKeyCtx, RSA_PKCS1_PSS_PADDING) > 0;
+  }
+  if (Result) {
+    Result = EVP_PKEY_CTX_set_rsa_pss_saltlen(pKeyCtx, SaltLen) > 0;
+  }
+  if (Result) {
+    Result = EVP_PKEY_CTX_set_rsa_mgf1_md(pKeyCtx, HashAlg) > 0;
+  }
+  if (Result) {
+    Result = EVP_DigestVerifyUpdate(pEvpVerifyCtx, Message, (UINT32)MsgSize) > 0;
+  }
+  if (Result) {
+    Result = EVP_DigestVerifyFinal(pEvpVerifyCtx, Signature, (UINT32)SigSize) > 0;
+  }
+
+_Exit :
+  if (pEvpRsaKey) {
+    EVP_PKEY_free(pEvpRsaKey);
+  }
+  if (pEvpVerifyCtx) {
+    EVP_MD_CTX_destroy(pEvpVerifyCtx);
+  }
+
+  return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssNull.c b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssNull.c
new file mode 100644
index 000000000000..69c6889fbc4b
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssNull.c
@@ -0,0 +1,46 @@
+/** @file
+  RSA-PSS Asymmetric Cipher Wrapper Implementation over OpenSSL.
+
+  This file does not provide real capabilities for following APIs in RSA handling:
+  1) RsaPssVerify
+
+Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+  Verifies the RSA signature with RSASSA-PSS signature scheme defined in RFC 8017.
+  Implementation determines salt length automatically from the signature encoding.
+  Mask generation function is the same as the message digest algorithm.
+  Salt length should atleast be equal to digest length.
+
+  @param[in]  RsaContext      Pointer to RSA context for signature verification.
+  @param[in]  Message         Pointer to octet message to be verified.
+  @param[in]  MsgSize         Size of the message in bytes.
+  @param[in]  Signature       Pointer to RSASSA-PSS signature to be verified.
+  @param[in]  SigSize         Size of signature in bytes.
+  @param[in]  DigestLen       Length of digest for RSA operation.
+  @param[in]  SaltLen         Salt length for PSS encoding.
+
+  @retval  TRUE   Valid signature encoded in RSASSA-PSS.
+  @retval  FALSE  Invalid signature or invalid RSA context.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssVerify (
+  IN  VOID         *RsaContext,
+  IN  CONST UINT8  *Message,
+  IN  UINTN        MsgSize,
+  IN  CONST UINT8  *Signature,
+  IN  UINTN        SigSize,
+  IN  UINT16       DigestLen,
+  IN  UINT16       SaltLen
+  )
+{
+  ASSERT (FALSE);
+  return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c
new file mode 100644
index 000000000000..7f798e82215a
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c
@@ -0,0 +1,168 @@
+/** @file
+  RSA PSS Asymmetric Cipher Wrapper Implementation over OpenSSL.
+
+  This file implements following APIs which provide basic capabilities for RSA:
+  1) RsaPssSign
+
+Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
+#include <openssl/objects.h>
+#include <openssl/evp.h>
+
+
+/**
+  Retrieve a pointer to EVP message digest object.
+
+  @param[in]  DigestLen   Length of the message digest.
+
+**/
+static
+EVP_MD*
+GetEvpMD (
+  IN UINT16 DigestLen
+  )
+{
+  switch (DigestLen){
+    case SHA256_DIGEST_SIZE:
+      return EVP_sha256();
+      break;
+    case SHA384_DIGEST_SIZE:
+      return EVP_sha384();
+      break;
+    case SHA512_DIGEST_SIZE:
+      return EVP_sha512();
+      break;
+    default:
+      return NULL;
+  }
+}
+
+
+/**
+  Carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme.
+
+  This function carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme defined in
+  RFC 8017.
+  Mask generation function is the same as the message digest algorithm.
+  If the Signature buffer is too small to hold the contents of signature, FALSE
+  is returned and SigSize is set to the required buffer size to obtain the signature.
+
+  If RsaContext is NULL, then return FALSE.
+  If Message is NULL, then return FALSE.
+  If MsgSize is zero or > INT_MAX, then return FALSE.
+  If DigestLen is NOT 32, 48 or 64, return FALSE.
+  If SaltLen is < DigestLen, then return FALSE.
+  If SigSize is large enough but Signature is NULL, then return FALSE.
+  If this interface is not supported, then return FALSE.
+
+  @param[in]      RsaContext   Pointer to RSA context for signature generation.
+  @param[in]      Message      Pointer to octet message to be signed.
+  @param[in]      MsgSize      Size of the message in bytes.
+  @param[in]      DigestLen    Length of the digest in bytes to be used for RSA signature operation.
+  @param[in]      SaltLen      Length of the salt in bytes to be used for PSS encoding.
+  @param[out]     Signature    Pointer to buffer to receive RSA PSS signature.
+  @param[in, out] SigSize      On input, the size of Signature buffer in bytes.
+                               On output, the size of data returned in Signature buffer in bytes.
+
+  @retval  TRUE   Signature successfully generated in RSASSA-PSS.
+  @retval  FALSE  Signature generation failed.
+  @retval  FALSE  SigSize is too small.
+  @retval  FALSE  This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssSign (
+  IN      VOID         *RsaContext,
+  IN      CONST UINT8  *Message,
+  IN      UINTN        MsgSize,
+  IN      UINT16       DigestLen,
+  IN      UINT16       SaltLen,
+  OUT     UINT8        *Signature,
+  IN OUT  UINTN        *SigSize
+  )
+{
+  BOOLEAN               Result;
+  UINTN                 RsaSigSize;
+  EVP_PKEY              *pEvpRsaKey = NULL;
+  EVP_MD_CTX            *pEvpVerifyCtx = NULL;
+  EVP_PKEY_CTX          *pKeyCtx = NULL;
+  CONST EVP_MD          *HashAlg = NULL;
+
+  if (RsaContext == NULL) {
+    return FALSE;
+  }
+  if (Message == NULL || MsgSize == 0 || MsgSize > INT_MAX) {
+    return FALSE;
+  }
+
+  RsaSigSize = RSA_size (RsaContext);
+  if (*SigSize < RsaSigSize) {
+    *SigSize = RsaSigSize;
+    return FALSE;
+  }
+
+  if (Signature == NULL) {
+    return FALSE;
+  }
+
+  if (SaltLen < DigestLen) {
+    return FALSE;
+  }
+
+  HashAlg = GetEvpMD(DigestLen);
+
+  if (HashAlg == NULL) {
+    return FALSE;
+  }
+
+  pEvpRsaKey = EVP_PKEY_new();
+  if (pEvpRsaKey == NULL) {
+    goto _Exit;
+  }
+
+  EVP_PKEY_set1_RSA(pEvpRsaKey, RsaContext);
+
+  pEvpVerifyCtx = EVP_MD_CTX_create();
+  if (pEvpVerifyCtx == NULL) {
+    goto _Exit;
+  }
+
+  Result = EVP_DigestSignInit(pEvpVerifyCtx, &pKeyCtx, HashAlg, NULL, pEvpRsaKey) > 0;
+  if (pKeyCtx == NULL) {
+    goto _Exit;
+  }
+
+  if (Result) {
+    Result = EVP_PKEY_CTX_set_rsa_padding(pKeyCtx, RSA_PKCS1_PSS_PADDING) > 0;
+  }
+  if (Result) {
+    Result = EVP_PKEY_CTX_set_rsa_pss_saltlen(pKeyCtx, SaltLen) > 0;
+  }
+  if (Result) {
+    Result = EVP_PKEY_CTX_set_rsa_mgf1_md(pKeyCtx, HashAlg) > 0;
+  }
+  if (Result) {
+    Result = EVP_DigestSignUpdate(pEvpVerifyCtx, Message, (UINT32)MsgSize) > 0;
+  }
+  if (Result) {
+    Result = EVP_DigestSignFinal(pEvpVerifyCtx, Signature, SigSize) > 0;
+  }
+
+_Exit :
+  if (pEvpRsaKey) {
+    EVP_PKEY_free(pEvpRsaKey);
+  }
+  if (pEvpVerifyCtx) {
+    EVP_MD_CTX_destroy(pEvpVerifyCtx);
+  }
+
+  return Result;
+}
diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSignNull.c b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSignNull.c
new file mode 100644
index 000000000000..4ed2dfce992a
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSignNull.c
@@ -0,0 +1,60 @@
+/** @file
+  RSA-PSS Asymmetric Cipher Wrapper Implementation over OpenSSL.
+
+  This file does not provide real capabilities for following APIs in RSA handling:
+  1) RsaPssSign
+
+Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+  Carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme.
+
+  This function carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme defined in
+  RFC 8017.
+  Mask generation function is the same as the message digest algorithm.
+  If the Signature buffer is too small to hold the contents of signature, FALSE
+  is returned and SigSize is set to the required buffer size to obtain the signature.
+
+  If RsaContext is NULL, then return FALSE.
+  If Message is NULL, then return FALSE.
+  If MsgSize is zero or > INT_MAX, then return FALSE.
+  If DigestLen is NOT 32, 48 or 64, return FALSE.
+  If SaltLen is < DigestLen, then return FALSE.
+  If SigSize is large enough but Signature is NULL, then return FALSE.
+  If this interface is not supported, then return FALSE.
+
+  @param[in]      RsaContext   Pointer to RSA context for signature generation.
+  @param[in]      Message      Pointer to octet message to be signed.
+  @param[in]      MsgSize      Size of the message in bytes.
+  @param[in]      DigestLen    Length of the digest in bytes to be used for RSA signature operation.
+  @param[in]      SaltLen      Length of the salt in bytes to be used for PSS encoding.
+  @param[out]     Signature    Pointer to buffer to receive RSA PSS signature.
+  @param[in, out] SigSize      On input, the size of Signature buffer in bytes.
+                               On output, the size of data returned in Signature buffer in bytes.
+
+  @retval  TRUE   Signature successfully generated in RSASSA-PSS.
+  @retval  FALSE  Signature generation failed.
+  @retval  FALSE  SigSize is too small.
+  @retval  FALSE  This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssSign (
+  IN      VOID         *RsaContext,
+  IN      CONST UINT8  *Message,
+  IN      UINTN        MsgSize,
+  IN      UINT16       DigestLen,
+  IN      UINT16       SaltLen,
+  OUT     UINT8        *Signature,
+  IN OUT  UINTN        *SigSize
+  )
+{
+  ASSERT (FALSE);
+  return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Pk/CryptRsaPssNull.c b/CryptoPkg/Library/BaseCryptLibNull/Pk/CryptRsaPssNull.c
new file mode 100644
index 000000000000..69c6889fbc4b
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Pk/CryptRsaPssNull.c
@@ -0,0 +1,46 @@
+/** @file
+  RSA-PSS Asymmetric Cipher Wrapper Implementation over OpenSSL.
+
+  This file does not provide real capabilities for following APIs in RSA handling:
+  1) RsaPssVerify
+
+Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+  Verifies the RSA signature with RSASSA-PSS signature scheme defined in RFC 8017.
+  Implementation determines salt length automatically from the signature encoding.
+  Mask generation function is the same as the message digest algorithm.
+  Salt length should atleast be equal to digest length.
+
+  @param[in]  RsaContext      Pointer to RSA context for signature verification.
+  @param[in]  Message         Pointer to octet message to be verified.
+  @param[in]  MsgSize         Size of the message in bytes.
+  @param[in]  Signature       Pointer to RSASSA-PSS signature to be verified.
+  @param[in]  SigSize         Size of signature in bytes.
+  @param[in]  DigestLen       Length of digest for RSA operation.
+  @param[in]  SaltLen         Salt length for PSS encoding.
+
+  @retval  TRUE   Valid signature encoded in RSASSA-PSS.
+  @retval  FALSE  Invalid signature or invalid RSA context.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssVerify (
+  IN  VOID         *RsaContext,
+  IN  CONST UINT8  *Message,
+  IN  UINTN        MsgSize,
+  IN  CONST UINT8  *Signature,
+  IN  UINTN        SigSize,
+  IN  UINT16       DigestLen,
+  IN  UINT16       SaltLen
+  )
+{
+  ASSERT (FALSE);
+  return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibNull/Pk/CryptRsaPssSignNull.c b/CryptoPkg/Library/BaseCryptLibNull/Pk/CryptRsaPssSignNull.c
new file mode 100644
index 000000000000..4ed2dfce992a
--- /dev/null
+++ b/CryptoPkg/Library/BaseCryptLibNull/Pk/CryptRsaPssSignNull.c
@@ -0,0 +1,60 @@
+/** @file
+  RSA-PSS Asymmetric Cipher Wrapper Implementation over OpenSSL.
+
+  This file does not provide real capabilities for following APIs in RSA handling:
+  1) RsaPssSign
+
+Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+
+/**
+  Carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme.
+
+  This function carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme defined in
+  RFC 8017.
+  Mask generation function is the same as the message digest algorithm.
+  If the Signature buffer is too small to hold the contents of signature, FALSE
+  is returned and SigSize is set to the required buffer size to obtain the signature.
+
+  If RsaContext is NULL, then return FALSE.
+  If Message is NULL, then return FALSE.
+  If MsgSize is zero or > INT_MAX, then return FALSE.
+  If DigestLen is NOT 32, 48 or 64, return FALSE.
+  If SaltLen is < DigestLen, then return FALSE.
+  If SigSize is large enough but Signature is NULL, then return FALSE.
+  If this interface is not supported, then return FALSE.
+
+  @param[in]      RsaContext   Pointer to RSA context for signature generation.
+  @param[in]      Message      Pointer to octet message to be signed.
+  @param[in]      MsgSize      Size of the message in bytes.
+  @param[in]      DigestLen    Length of the digest in bytes to be used for RSA signature operation.
+  @param[in]      SaltLen      Length of the salt in bytes to be used for PSS encoding.
+  @param[out]     Signature    Pointer to buffer to receive RSA PSS signature.
+  @param[in, out] SigSize      On input, the size of Signature buffer in bytes.
+                               On output, the size of data returned in Signature buffer in bytes.
+
+  @retval  TRUE   Signature successfully generated in RSASSA-PSS.
+  @retval  FALSE  Signature generation failed.
+  @retval  FALSE  SigSize is too small.
+  @retval  FALSE  This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssSign (
+  IN      VOID         *RsaContext,
+  IN      CONST UINT8  *Message,
+  IN      UINTN        MsgSize,
+  IN      UINT16       DigestLen,
+  IN      UINT16       SaltLen,
+  OUT     UINT8        *Signature,
+  IN OUT  UINTN        *SigSize
+  )
+{
+  ASSERT (FALSE);
+  return FALSE;
+}
diff --git a/CryptoPkg/Library/BaseCryptLibOnProtocolPpi/CryptLib.c b/CryptoPkg/Library/BaseCryptLibOnProtocolPpi/CryptLib.c
index 8b43d1363cb9..412fbdbff52c 100644
--- a/CryptoPkg/Library/BaseCryptLibOnProtocolPpi/CryptLib.c
+++ b/CryptoPkg/Library/BaseCryptLibOnProtocolPpi/CryptLib.c
@@ -1552,6 +1552,72 @@ RsaPkcs1Verify (
   CALL_CRYPTO_SERVICE (RsaPkcs1Verify, (RsaContext, MessageHash, HashSize, Signature, SigSize), FALSE);
 }
 
+/**
+  Verifies the RSA signature with RSASSA-PSS signature scheme defined in RFC 8017.
+  Implementation determines salt length automatically from the signature encoding.
+  Mask generation function is the same as the message digest algorithm.
+  Salt length should atleast be equal to digest length.
+
+  @param[in]  RsaContext      Pointer to RSA context for signature verification.
+  @param[in]  Message         Pointer to octet message to be verified.
+  @param[in]  MsgSize         Size of the message in bytes.
+  @param[in]  Signature       Pointer to RSASSA-PSS signature to be verified.
+  @param[in]  SigSize         Size of signature in bytes.
+  @param[in]  DigestLen       Length of digest for RSA operation.
+  @param[in]  SaltLen         Salt length for PSS encoding.
+
+  @retval  TRUE   Valid signature encoded in RSASSA-PSS.
+  @retval  FALSE  Invalid signature or invalid RSA context.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssVerify (
+  IN  VOID         *RsaContext,
+  IN  CONST UINT8  *Message,
+  IN  UINTN        MsgSize,
+  IN  CONST UINT8  *Signature,
+  IN  UINTN        SigSize,
+  IN  UINT16       DigestLen,
+  IN  UINT16       SaltLen
+  )
+{
+  CALL_CRYPTO_SERVICE (RsaPssVerify, (RsaContext, Message, MsgSize, Signature, SigSize, DigestLen, SaltLen), FALSE);
+}
+
+/**
+  Verifies the RSA signature with RSASSA-PSS signature scheme defined in RFC 8017.
+  Implementation determines salt length automatically from the signature encoding.
+  Mask generation function is the same as the message digest algorithm.
+  Salt length should atleast be equal to digest length.
+
+  @param[in]  RsaContext      Pointer to RSA context for signature verification.
+  @param[in]  Message         Pointer to octet message to be verified.
+  @param[in]  MsgSize         Size of the message in bytes.
+  @param[in]  Signature       Pointer to RSASSA-PSS signature to be verified.
+  @param[in]  SigSize         Size of signature in bytes.
+  @param[in]  DigestLen       Length of digest for RSA operation.
+  @param[in]  SaltLen         Salt length for PSS encoding.
+
+  @retval  TRUE   Valid signature encoded in RSASSA-PSS.
+  @retval  FALSE  Invalid signature or invalid RSA context.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssSign (
+  IN      VOID         *RsaContext,
+  IN      CONST UINT8  *Message,
+  IN      UINTN        MsgSize,
+  IN      UINT16       DigestLen,
+  IN      UINT16       SaltLen,
+  OUT     UINT8        *Signature,
+  IN OUT  UINTN        *SigSize
+  )
+{
+  CALL_CRYPTO_SERVICE (RsaPssSign, (RsaContext, Message, MsgSize, DigestLen, SaltLen, Signature, SigSize), FALSE);
+}
+
 /**
   Retrieve the RSA Private Key from the password-protected PEM key data.
 
diff --git a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/BaseCryptLibUnitTests.c b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/BaseCryptLibUnitTests.c
index b7fcea3ff7e4..3873de973064 100644
--- a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/BaseCryptLibUnitTests.c
+++ b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/BaseCryptLibUnitTests.c
@@ -16,6 +16,7 @@ SUITE_DESC  mSuiteDesc[] = {
     {"HMAC verify tests",           "CryptoPkg.BaseCryptLib", NULL, NULL, &mHmacTestNum,           mHmacTest},
     {"BlockCipher verify tests",    "CryptoPkg.BaseCryptLib", NULL, NULL, &mBlockCipherTestNum,    mBlockCipherTest},
     {"RSA verify tests",            "CryptoPkg.BaseCryptLib", NULL, NULL, &mRsaTestNum,            mRsaTest},
+    {"RSA PSS verify tests",        "CryptoPkg.BaseCryptLib", NULL, NULL, &mRsaPssTestNum,         mRsaPssTest},
     {"RSACert verify tests",        "CryptoPkg.BaseCryptLib", NULL, NULL, &mRsaCertTestNum,        mRsaCertTest},
     {"PKCS7 verify tests",          "CryptoPkg.BaseCryptLib", NULL, NULL, &mPkcs7TestNum,          mPkcs7Test},
     {"PKCS5 verify tests",          "CryptoPkg.BaseCryptLib", NULL, NULL, &mPkcs5TestNum,          mPkcs5Test},
diff --git a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaPssTests.c b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaPssTests.c
new file mode 100644
index 000000000000..5ac2f325fbdd
--- /dev/null
+++ b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaPssTests.c
@@ -0,0 +1,191 @@
+/** @file
+  Application for RSA PSS Primitives Validation.
+
+Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "TestBaseCryptLib.h"
+
+//
+// RSA PSS test vectors from NIST FIPS 186-3 RSA files
+//
+
+//
+// Public Modulus of RSA Key
+//
+UINT8 RsaPssN[]={
+    0xa4, 0x7d, 0x04, 0xe7, 0xca, 0xcd, 0xba, 0x4e, 0xa2, 0x6e, 0xca, 0x8a, 0x4c, 0x6e, 0x14, 0x56,
+    0x3c, 0x2c, 0xe0, 0x3b, 0x62, 0x3b, 0x76, 0x8c, 0x0d, 0x49, 0x86, 0x8a, 0x57, 0x12, 0x13, 0x01,
+    0xdb, 0xf7, 0x83, 0xd8, 0x2f, 0x4c, 0x05, 0x5e, 0x73, 0x96, 0x0e, 0x70, 0x55, 0x01, 0x87, 0xd0,
+    0xaf, 0x62, 0xac, 0x34, 0x96, 0xf0, 0xa3, 0xd9, 0x10, 0x3c, 0x2e, 0xb7, 0x91, 0x9a, 0x72, 0x75,
+    0x2f, 0xa7, 0xce, 0x8c, 0x68, 0x8d, 0x81, 0xe3, 0xae, 0xe9, 0x94, 0x68, 0x88, 0x7a, 0x15, 0x28,
+    0x8a, 0xfb, 0xb7, 0xac, 0xb8, 0x45, 0xb7, 0xc5, 0x22, 0xb5, 0xc6, 0x4e, 0x67, 0x8f, 0xcd, 0x3d,
+    0x22, 0xfe, 0xb8, 0x4b, 0x44, 0x27, 0x27, 0x00, 0xbe, 0x52, 0x7d, 0x2b, 0x20, 0x25, 0xa3, 0xf8,
+    0x3c, 0x23, 0x83, 0xbf, 0x6a, 0x39, 0xcf, 0x5b, 0x4e, 0x48, 0xb3, 0xcf, 0x2f, 0x56, 0xee, 0xf0,
+    0xdf, 0xff, 0x18, 0x55, 0x5e, 0x31, 0x03, 0x7b, 0x91, 0x52, 0x48, 0x69, 0x48, 0x76, 0xf3, 0x04,
+    0x78, 0x14, 0x41, 0x51, 0x64, 0xf2, 0xc6, 0x60, 0x88, 0x1e, 0x69, 0x4b, 0x58, 0xc2, 0x80, 0x38,
+    0xa0, 0x32, 0xad, 0x25, 0x63, 0x4a, 0xad, 0x7b, 0x39, 0x17, 0x1d, 0xee, 0x36, 0x8e, 0x3d, 0x59,
+    0xbf, 0xb7, 0x29, 0x9e, 0x46, 0x01, 0xd4, 0x58, 0x7e, 0x68, 0xca, 0xaf, 0x8d, 0xb4, 0x57, 0xb7,
+    0x5a, 0xf4, 0x2f, 0xc0, 0xcf, 0x1a, 0xe7, 0xca, 0xce, 0xd2, 0x86, 0xd7, 0x7f, 0xac, 0x6c, 0xed,
+    0xb0, 0x3a, 0xd9, 0x4f, 0x14, 0x33, 0xd2, 0xc9, 0x4d, 0x08, 0xe6, 0x0b, 0xc1, 0xfd, 0xef, 0x05,
+    0x43, 0xcd, 0x29, 0x51, 0xe7, 0x65, 0xb3, 0x82, 0x30, 0xfd, 0xd1, 0x8d, 0xe5, 0xd2, 0xca, 0x62,
+    0x7d, 0xdc, 0x03, 0x2f, 0xe0, 0x5b, 0xbd, 0x2f, 0xf2, 0x1e, 0x2d, 0xb1, 0xc2, 0xf9, 0x4d, 0x8b,
+    };
+
+//
+// Public Exponent of RSA Key
+//
+UINT8 RsaPssE[]={ 0x10, 0xe4, 0x3f };
+
+//
+// Private Exponent of RSA Key
+//
+UINT8 RsaPssD[]={
+    0x11, 0xa0, 0xdd, 0x28, 0x5f, 0x66, 0x47, 0x1a, 0x8d, 0xa3, 0x0b, 0xcb, 0x8c, 0x24, 0xa1, 0xd5,
+    0xc8, 0xdb, 0x94, 0x2f, 0xc9, 0x92, 0x07, 0x97, 0xca, 0x44, 0x24, 0x60, 0xa8, 0x00, 0xb7, 0x5b,
+    0xbc, 0x73, 0x8b, 0xeb, 0x8e, 0xe0, 0xe8, 0x74, 0xb0, 0x53, 0xe6, 0x47, 0x07, 0xdf, 0x4c, 0xfc,
+    0x78, 0x37, 0xc4, 0x0e, 0x5b, 0xe6, 0x8b, 0x8a, 0x8e, 0x1d, 0x01, 0x45, 0x16, 0x9c, 0xa6, 0x27,
+    0x1d, 0x81, 0x88, 0x7e, 0x19, 0xa1, 0xcd, 0x95, 0xb2, 0xfd, 0x0d, 0xe0, 0xdb, 0xa3, 0x47, 0xfe,
+    0x63, 0x7b, 0xcc, 0x6c, 0xdc, 0x24, 0xee, 0xbe, 0x03, 0xc2, 0x4d, 0x4c, 0xf3, 0xa5, 0xc6, 0x15,
+    0x4d, 0x78, 0xf1, 0x41, 0xfe, 0x34, 0x16, 0x99, 0x24, 0xd0, 0xf8, 0x95, 0x33, 0x65, 0x8e, 0xac,
+    0xfd, 0xea, 0xe9, 0x9c, 0xe1, 0xa8, 0x80, 0x27, 0xc1, 0x8f, 0xf9, 0x26, 0x53, 0xa8, 0x35, 0xaa,
+    0x38, 0x91, 0xbf, 0xff, 0xcd, 0x38, 0x8f, 0xfc, 0x23, 0x88, 0xce, 0x2b, 0x10, 0x56, 0x85, 0x43,
+    0x75, 0x05, 0x02, 0xcc, 0xbc, 0x69, 0xc0, 0x08, 0x8f, 0x1d, 0x69, 0x0e, 0x97, 0xa5, 0xf5, 0xbd,
+    0xd1, 0x88, 0x8c, 0xd2, 0xfa, 0xa4, 0x3c, 0x04, 0xae, 0x24, 0x53, 0x95, 0x22, 0xdd, 0xe2, 0xd9,
+    0xc2, 0x02, 0xf6, 0x55, 0xfc, 0x55, 0x75, 0x44, 0x40, 0xb5, 0x3a, 0x15, 0x32, 0xaa, 0xb4, 0x78,
+    0x51, 0xf6, 0x0b, 0x7a, 0x06, 0x7e, 0x24, 0x0b, 0x73, 0x8e, 0x1b, 0x1d, 0xaa, 0xe6, 0xca, 0x0d,
+    0x59, 0xee, 0xae, 0x27, 0x68, 0x6c, 0xd8, 0x88, 0x57, 0xe9, 0xad, 0xad, 0xc2, 0xd4, 0xb8, 0x2b,
+    0x07, 0xa6, 0x1a, 0x35, 0x84, 0x56, 0xaa, 0xf8, 0x07, 0x66, 0x96, 0x93, 0xff, 0xb1, 0x3c, 0x99,
+    0x64, 0xa6, 0x36, 0x54, 0xca, 0xdc, 0x81, 0xee, 0x59, 0xdf, 0x51, 0x1c, 0xa3, 0xa4, 0xbd, 0x67,
+    };
+
+//
+// Binary message to be signed and verified
+//
+UINT8 PssMessage[]={
+    0xe0, 0x02, 0x37, 0x7a, 0xff, 0xb0, 0x4f, 0x0f, 0xe4, 0x59, 0x8d, 0xe9, 0xd9, 0x2d, 0x31, 0xd6,
+    0xc7, 0x86, 0x04, 0x0d, 0x57, 0x76, 0x97, 0x65, 0x56, 0xa2, 0xcf, 0xc5, 0x5e, 0x54, 0xa1, 0xdc,
+    0xb3, 0xcb, 0x1b, 0x12, 0x6b, 0xd6, 0xa4, 0xbe, 0xd2, 0xa1, 0x84, 0x99, 0x0c, 0xce, 0xa7, 0x73,
+    0xfc, 0xc7, 0x9d, 0x24, 0x65, 0x53, 0xe6, 0xc6, 0x4f, 0x68, 0x6d, 0x21, 0xad, 0x41, 0x52, 0x67,
+    0x3c, 0xaf, 0xec, 0x22, 0xae, 0xb4, 0x0f, 0x6a, 0x08, 0x4e, 0x8a, 0x5b, 0x49, 0x91, 0xf4, 0xc6,
+    0x4c, 0xf8, 0xa9, 0x27, 0xef, 0xfd, 0x0f, 0xd7, 0x75, 0xe7, 0x1e, 0x83, 0x29, 0xe4, 0x1f, 0xdd,
+    0x44, 0x57, 0xb3, 0x91, 0x11, 0x73, 0x18, 0x7b, 0x4f, 0x09, 0xa8, 0x17, 0xd7, 0x9e, 0xa2, 0x39,
+    0x7f, 0xc1, 0x2d, 0xfe, 0x3d, 0x9c, 0x9a, 0x02, 0x90, 0xc8, 0xea, 0xd3, 0x1b, 0x66, 0x90, 0xa6,
+    };
+
+//
+// Binary message to be signed and verified
+//
+UINT8 PssSalt[]={
+    0xd6, 0x6f, 0x72, 0xf1, 0x0b, 0x69, 0x00, 0x1a, 0x5b, 0x59, 0xcf, 0x10, 0x92, 0xad, 0x27, 0x4d,
+    0x50, 0x56, 0xc4, 0xe9, 0x5c, 0xcc, 0xcf, 0xbe, 0x3b, 0x53, 0x0d, 0xcb, 0x02, 0x7e, 0x57, 0xd6
+    };
+
+//
+// RSASSA-PSS Signature over above message using above keys, salt and SHA256 digest(and MGF1) algo.
+//
+UINT8 TestVectorSignature[]={
+    0x4f, 0x9b, 0x42, 0x5c, 0x20, 0x58, 0x46, 0x0e, 0x4a, 0xb2, 0xf5, 0xc9, 0x63, 0x84, 0xda, 0x23,
+    0x27, 0xfd, 0x29, 0x15, 0x0f, 0x01, 0x95, 0x5a, 0x76, 0xb4, 0xef, 0xe9, 0x56, 0xaf, 0x06, 0xdc,
+    0x08, 0x77, 0x9a, 0x37, 0x4e, 0xe4, 0x60, 0x7e, 0xab, 0x61, 0xa9, 0x3a, 0xdc, 0x56, 0x08, 0xf4,
+    0xec, 0x36, 0xe4, 0x7f, 0x2a, 0x0f, 0x75, 0x4e, 0x8f, 0xf8, 0x39, 0xa8, 0xa1, 0x9b, 0x1d, 0xb1,
+    0xe8, 0x84, 0xea, 0x4c, 0xf3, 0x48, 0xcd, 0x45, 0x50, 0x69, 0xeb, 0x87, 0xaf, 0xd5, 0x36, 0x45,
+    0xb4, 0x4e, 0x28, 0xa0, 0xa5, 0x68, 0x08, 0xf5, 0x03, 0x1d, 0xa5, 0xba, 0x91, 0x12, 0x76, 0x8d,
+    0xfb, 0xfc, 0xa4, 0x4e, 0xbe, 0x63, 0xa0, 0xc0, 0x57, 0x2b, 0x73, 0x1d, 0x66, 0x12, 0x2f, 0xb7,
+    0x16, 0x09, 0xbe, 0x14, 0x80, 0xfa, 0xa4, 0xe4, 0xf7, 0x5e, 0x43, 0x95, 0x51, 0x59, 0xd7, 0x0f,
+    0x08, 0x1e, 0x2a, 0x32, 0xfb, 0xb1, 0x9a, 0x48, 0xb9, 0xf1, 0x62, 0xcf, 0x6b, 0x2f, 0xb4, 0x45,
+    0xd2, 0xd6, 0x99, 0x4b, 0xc5, 0x89, 0x10, 0xa2, 0x6b, 0x59, 0x43, 0x47, 0x78, 0x03, 0xcd, 0xaa,
+    0xa1, 0xbd, 0x74, 0xb0, 0xda, 0x0a, 0x5d, 0x05, 0x3d, 0x8b, 0x1d, 0xc5, 0x93, 0x09, 0x1d, 0xb5,
+    0x38, 0x83, 0x83, 0xc2, 0x60, 0x79, 0xf3, 0x44, 0xe2, 0xae, 0xa6, 0x00, 0xd0, 0xe3, 0x24, 0x16,
+    0x4b, 0x45, 0x0f, 0x7b, 0x9b, 0x46, 0x51, 0x11, 0xb7, 0x26, 0x5f, 0x3b, 0x1b, 0x06, 0x30, 0x89,
+    0xae, 0x7e, 0x26, 0x23, 0xfc, 0x0f, 0xda, 0x80, 0x52, 0xcf, 0x4b, 0xf3, 0x37, 0x91, 0x02, 0xfb,
+    0xf7, 0x1d, 0x7c, 0x98, 0xe8, 0x25, 0x86, 0x64, 0xce, 0xed, 0x63, 0x7d, 0x20, 0xf9, 0x5f, 0xf0,
+    0x11, 0x18, 0x81, 0xe6, 0x50, 0xce, 0x61, 0xf2, 0x51, 0xd9, 0xc3, 0xa6, 0x29, 0xef, 0x22, 0x2d,
+    };
+
+
+VOID     *mRsa;
+
+UNIT_TEST_STATUS
+EFIAPI
+TestVerifyRsaPssPreReq (
+  UNIT_TEST_CONTEXT           Context
+  )
+{
+  mRsa = RsaNew ();
+
+  if (mRsa == NULL) {
+    return UNIT_TEST_ERROR_TEST_FAILED;
+  }
+
+  return UNIT_TEST_PASSED;
+}
+
+VOID
+EFIAPI
+TestVerifyRsaPssCleanUp (
+  UNIT_TEST_CONTEXT           Context
+  )
+{
+  if (mRsa != NULL) {
+    RsaFree (mRsa);
+    mRsa = NULL;
+  }
+}
+
+
+UNIT_TEST_STATUS
+EFIAPI
+TestVerifyRsaPssSignVerify (
+  IN UNIT_TEST_CONTEXT           Context
+  )
+{
+  UINT8    *Signature;
+  UINTN    SigSize;
+  BOOLEAN  Status;
+
+  Status = RsaSetKey (mRsa, RsaKeyN, RsaPssN, sizeof (RsaPssN));
+  UT_ASSERT_TRUE (Status);
+
+  Status = RsaSetKey (mRsa, RsaKeyE, RsaPssE, sizeof (RsaPssE));
+  UT_ASSERT_TRUE (Status);
+
+  Status = RsaSetKey (mRsa, RsaKeyD, RsaPssD, sizeof (RsaPssD));
+  UT_ASSERT_TRUE (Status);
+
+  SigSize = 0;
+  Status = RsaPssSign (mRsa, PssMessage, sizeof(PssMessage), SHA256_DIGEST_SIZE, SHA256_DIGEST_SIZE, NULL, &SigSize);
+  UT_ASSERT_FALSE (Status);
+  UT_ASSERT_NOT_EQUAL (SigSize, 0);
+
+  Signature = AllocatePool (SigSize);
+  Status = RsaPssSign (mRsa, PssMessage, sizeof(PssMessage), SHA256_DIGEST_SIZE, SHA256_DIGEST_SIZE, Signature, &SigSize);
+  UT_ASSERT_TRUE (Status);
+
+  //
+  // Verify RSA PSS encoded Signature generated in above step
+  //
+  Status = RsaPssVerify (mRsa, PssMessage, sizeof(PssMessage), Signature, SigSize, SHA256_DIGEST_SIZE, SHA256_DIGEST_SIZE);
+  UT_ASSERT_TRUE (Status);
+
+  //
+  // Verify NIST FIPS 186-3 RSA test vector signature
+  //
+  Status = RsaPssVerify (mRsa, PssMessage, sizeof(PssMessage), TestVectorSignature, sizeof(TestVectorSignature), SHA256_DIGEST_SIZE, SHA256_DIGEST_SIZE);
+  UT_ASSERT_TRUE (Status);
+
+  FreePool(Signature);
+  return UNIT_TEST_PASSED;
+}
+
+
+TEST_DESC mRsaPssTest[] = {
+    //
+    // -----Description--------------------------------------Class----------------------Function---------------------------------Pre---------------------Post---------Context
+    //
+    {"TestVerifyRsaPssSignVerify()",           "CryptoPkg.BaseCryptLib.Rsa",   TestVerifyRsaPssSignVerify,           TestVerifyRsaPssPreReq, TestVerifyRsaPssCleanUp, NULL},
+};
+
+UINTN mRsaPssTestNum = ARRAY_SIZE(mRsaPssTest);
diff --git a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaTests.c b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaTests.c
index 7ce20d2e778f..0969b6aea660 100644
--- a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaTests.c
+++ b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/RsaTests.c
@@ -295,6 +295,8 @@ TestVerifyRsaPkcs1SignVerify (
   Status = RsaPkcs1Verify (mRsa, HashValue, HashSize, Signature, SigSize);
   UT_ASSERT_TRUE (Status);
 
+  FreePool(Signature);
+
   return UNIT_TEST_PASSED;
 }
 
diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h b/CryptoPkg/Include/Library/BaseCryptLib.h
index 496121e6a4ed..8c7d5922ef96 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -1363,6 +1363,80 @@ RsaPkcs1Verify (
   IN  UINTN        SigSize
   );
 
+/**
+  Carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme.
+
+  This function carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme defined in
+  RFC 8017.
+  Mask generation function is the same as the message digest algorithm.
+  If the Signature buffer is too small to hold the contents of signature, FALSE
+  is returned and SigSize is set to the required buffer size to obtain the signature.
+
+  If RsaContext is NULL, then return FALSE.
+  If Message is NULL, then return FALSE.
+  If MsgSize is zero or > INT_MAX, then return FALSE.
+  If DigestLen is NOT 32, 48 or 64, return FALSE.
+  If SaltLen is < DigestLen, then return FALSE.
+  If SigSize is large enough but Signature is NULL, then return FALSE.
+  If this interface is not supported, then return FALSE.
+
+  @param[in]      RsaContext   Pointer to RSA context for signature generation.
+  @param[in]      Message      Pointer to octet message to be signed.
+  @param[in]      MsgSize      Size of the message in bytes.
+  @param[in]      DigestLen    Length of the digest in bytes to be used for RSA signature operation.
+  @param[in]      SaltLen      Length of the salt in bytes to be used for PSS encoding.
+  @param[out]     Signature    Pointer to buffer to receive RSA PSS signature.
+  @param[in, out] SigSize      On input, the size of Signature buffer in bytes.
+                               On output, the size of data returned in Signature buffer in bytes.
+
+  @retval  TRUE   Signature successfully generated in RSASSA-PSS.
+  @retval  FALSE  Signature generation failed.
+  @retval  FALSE  SigSize is too small.
+  @retval  FALSE  This interface is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssSign (
+  IN      VOID         *RsaContext,
+  IN      CONST UINT8  *Message,
+  IN      UINTN        MsgSize,
+  IN      UINT16       DigestLen,
+  IN      UINT16       SaltLen,
+  OUT     UINT8        *Signature,
+  IN OUT  UINTN        *SigSize
+  );
+
+/**
+  Verifies the RSA signature with RSASSA-PSS signature scheme defined in RFC 8017.
+  Implementation determines salt length automatically from the signature encoding.
+  Mask generation function is the same as the message digest algorithm.
+  Salt length should atleast be equal to digest length.
+
+  @param[in]  RsaContext      Pointer to RSA context for signature verification.
+  @param[in]  Message         Pointer to octet message to be verified.
+  @param[in]  MsgSize         Size of the message in bytes.
+  @param[in]  Signature       Pointer to RSASSA-PSS signature to be verified.
+  @param[in]  SigSize         Size of signature in bytes.
+  @param[in]  DigestLen       Length of digest for RSA operation.
+  @param[in]  SaltLen         Salt length for PSS encoding.
+
+  @retval  TRUE   Valid signature encoded in RSASSA-PSS.
+  @retval  FALSE  Invalid signature or invalid RSA context.
+
+**/
+BOOLEAN
+EFIAPI
+RsaPssVerify (
+  IN  VOID         *RsaContext,
+  IN  CONST UINT8  *Message,
+  IN  UINTN        MsgSize,
+  IN  CONST UINT8  *Signature,
+  IN  UINTN        SigSize,
+  IN  UINT16       DigestLen,
+  IN  UINT16       SaltLen
+  );
+
 /**
   Retrieve the RSA Private Key from the password-protected PEM key data.
 
diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
index 4aae2aba95d6..49703fa4c963 100644
--- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
@@ -49,6 +49,8 @@
   Pk/CryptX509.c
   Pk/CryptAuthenticode.c
   Pk/CryptTs.c
+  Pk/CryptRsaPss.c
+  Pk/CryptRsaPssSign.c
   Pem/CryptPem.c
 
   SysCall/CrtWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
index 7509e4273028..0cab5f3ce36c 100644
--- a/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf
@@ -55,6 +55,8 @@
   Pk/CryptX509Null.c
   Pk/CryptAuthenticodeNull.c
   Pk/CryptTsNull.c
+  Pk/CryptRsaPss.c
+  Pk/CryptRsaPssSignNull.c
   Pem/CryptPemNull.c
   Rand/CryptRandNull.c
 
diff --git a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
index 70c985ec93dc..3d3a6fb94a77 100644
--- a/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/RuntimeCryptLib.inf
@@ -55,6 +55,8 @@
   Pk/CryptX509.c
   Pk/CryptAuthenticodeNull.c
   Pk/CryptTsNull.c
+  Pk/CryptRsaPssNull.c
+  Pk/CryptRsaPssSignNull.c
   Pem/CryptPem.c
 
   SysCall/CrtWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
index 91ec3e03bf5e..07c376ce04bb 100644
--- a/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
@@ -53,6 +53,8 @@
   Pk/CryptX509.c
   Pk/CryptAuthenticodeNull.c
   Pk/CryptTsNull.c
+  Pk/CryptRsaPss.c
+  Pk/CryptRsaPssSignNull.c
   Pem/CryptPem.c
 
   SysCall/CrtWrapper.c
diff --git a/CryptoPkg/Library/BaseCryptLib/UnitTestHostBaseCryptLib.inf b/CryptoPkg/Library/BaseCryptLib/UnitTestHostBaseCryptLib.inf
index db506c32f724..b98f9635b27b 100644
--- a/CryptoPkg/Library/BaseCryptLib/UnitTestHostBaseCryptLib.inf
+++ b/CryptoPkg/Library/BaseCryptLib/UnitTestHostBaseCryptLib.inf
@@ -44,6 +44,8 @@
   Pk/CryptAuthenticode.c
   Pk/CryptTs.c
   Pem/CryptPem.c
+  Pk/CryptRsaPss.c
+  Pk/CryptRsaPssSign.c
 
   SysCall/UnitTestHostCrtWrapper.c
 
diff --git a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
index 689af4fedd68..faf959827b90 100644
--- a/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
+++ b/CryptoPkg/Library/BaseCryptLibNull/BaseCryptLibNull.inf
@@ -50,6 +50,8 @@
   Pk/CryptTsNull.c
   Pem/CryptPemNull.c
   Rand/CryptRandNull.c
+  Pk/CryptRsaPssNull.c
+  Pk/CryptRsaPssSignNull.c
 
 [Packages]
   MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Private/Protocol/Crypto.h b/CryptoPkg/Private/Protocol/Crypto.h
index 17930a77a60e..e304302c9445 100644
--- a/CryptoPkg/Private/Protocol/Crypto.h
+++ b/CryptoPkg/Private/Protocol/Crypto.h
@@ -3408,6 +3408,81 @@ EFI_STATUS
   IN OUT UINTN                    *DataSize
   );
 
+/**
+  Carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme.
+
+  This function carries out the RSA-SSA signature generation with EMSA-PSS encoding scheme defined in
+  RFC 8017.
+  Mask generation function is the same as the message digest algorithm.
+  If the Signature buffer is too small to hold the contents of signature, FALSE
+  is returned and SigSize is set to the required buffer size to obtain the signature.
+
+  If RsaContext is NULL, then return FALSE.
+  If Message is NULL, then return FALSE.
+  If MsgSize is zero or > INT_MAX, then return FALSE.
+  If DigestLen is NOT 32, 48 or 64, return FALSE.
+  If SaltLen is < DigestLen, then return FALSE.
+  If SigSize is large enough but Signature is NULL, then return FALSE.
+  If this interface is not supported, then return FALSE.
+
+  @param[in]      RsaContext   Pointer to RSA context for signature generation.
+  @param[in]      Message      Pointer to octet message to be signed.
+  @param[in]      MsgSize      Size of the message in bytes.
+  @param[in]      DigestLen    Length of the digest in bytes to be used for RSA signature operation.
+  @param[in]      SaltLen      Length of the salt in bytes to be used for PSS encoding.
+  @param[out]     Signature    Pointer to buffer to receive RSA PSS signature.
+  @param[in, out] SigSize      On input, the size of Signature buffer in bytes.
+                               On output, the size of data returned in Signature buffer in bytes.
+
+  @retval  TRUE   Signature successfully generated in RSASSA-PSS.
+  @retval  FALSE  Signature generation failed.
+  @retval  FALSE  SigSize is too small.
+  @retval  FALSE  This interface is not supported.
+
+**/
+typedef
+BOOLEAN
+(EFIAPI* EDKII_CRYPTO_RSA_PSS_SIGN)(
+  IN      VOID         *RsaContext,
+  IN      CONST UINT8  *Message,
+  IN      UINTN        MsgSize,
+  IN      UINT16       DigestLen,
+  IN      UINT16       SaltLen,
+  OUT     UINT8        *Signature,
+  IN OUT  UINTN        *SigSize
+  );
+
+/**
+  Verifies the RSA signature with RSASSA-PSS signature scheme defined in RFC 8017.
+  Implementation determines salt length automatically from the signature encoding.
+  Mask generation function is the same as the message digest algorithm.
+  Salt length should atleast be equal to digest length.
+
+  @param[in]  RsaContext      Pointer to RSA context for signature verification.
+  @param[in]  Message         Pointer to octet message to be verified.
+  @param[in]  MsgSize         Size of the message in bytes.
+  @param[in]  Signature       Pointer to RSASSA-PSS signature to be verified.
+  @param[in]  SigSize         Size of signature in bytes.
+  @param[in]  DigestLen       Length of digest for RSA operation.
+  @param[in]  SaltLen         Salt length for PSS encoding.
+
+  @retval  TRUE   Valid signature encoded in RSASSA-PSS.
+  @retval  FALSE  Invalid signature or invalid RSA context.
+
+**/
+typedef
+BOOLEAN
+(EFIAPI* EDKII_CRYPTO_RSA_PSS_VERIFY)(
+  IN  VOID         *RsaContext,
+  IN  CONST UINT8  *Message,
+  IN  UINTN        MsgSize,
+  IN  CONST UINT8  *Signature,
+  IN  UINTN        SigSize,
+  IN  UINT16       DigestLen,
+  IN  UINT16       SaltLen
+  );
+
+
 
 ///
 /// EDK II Crypto Protocol
@@ -3593,6 +3668,9 @@ struct _EDKII_CRYPTO_PROTOCOL {
   EDKII_CRYPTO_TLS_GET_HOST_PUBLIC_CERT           TlsGetHostPublicCert;
   EDKII_CRYPTO_TLS_GET_HOST_PRIVATE_KEY           TlsGetHostPrivateKey;
   EDKII_CRYPTO_TLS_GET_CERT_REVOCATION_LIST       TlsGetCertRevocationList;
+  /// RSA PSS
+  EDKII_CRYPTO_RSA_PSS_SIGN                       RsaPssSign;
+  EDKII_CRYPTO_RSA_PSS_VERIFY                     RsaPssVerify;
 };
 
 extern GUID gEdkiiCryptoProtocolGuid;
diff --git a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLib.h b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLib.h
index 9d1cb150a113..25c1379f1a77 100644
--- a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLib.h
+++ b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLib.h
@@ -83,6 +83,9 @@ extern TEST_DESC mPrngTest[];
 extern UINTN mOaepTestNum;
 extern TEST_DESC mOaepTest[];
 
+extern UINTN mRsaPssTestNum;
+extern TEST_DESC mRsaPssTest[];
+
 /** Creates a framework you can use */
 EFI_STATUS
 EFIAPI
diff --git a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibHost.inf b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibHost.inf
index 300b98e40b33..00c869265080 100644
--- a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibHost.inf
+++ b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibHost.inf
@@ -34,6 +34,7 @@
   RandTests.c
   Pkcs7EkuTests.c
   OaepEncryptTests.c
+  RsaPssTests.c
 
 [Packages]
   MdePkg/MdePkg.dec
diff --git a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibShell.inf b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibShell.inf
index d5e7e0d01446..ca789aa6ada3 100644
--- a/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibShell.inf
+++ b/CryptoPkg/Test/UnitTest/Library/BaseCryptLib/TestBaseCryptLibShell.inf
@@ -35,6 +35,7 @@
   RandTests.c
   Pkcs7EkuTests.c
   OaepEncryptTests.c
+  RsaPssTests.c
 
 [Packages]
   MdePkg/MdePkg.dec
-- 
2.14.3.windows.1