CryptoPkg/Library/BaseCryptLibOnProtocolPpi/PeiCryptLib.c

   1 /** @file
   2   Implements the GetCryptoServices() API that retuns a pointer to the EDK II
   3   Crypto PPI.
   4
   5   Copyright (C) Microsoft Corporation. All rights reserved.
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9 #include <PiPei.h>
  10 #include <Library/BaseLib.h>
  11 #include <Library/DebugLib.h>
  12 #include <Library/PeiServicesLib.h>
  13 #include <Ppi/Crypto.h>
  14
  15 /**
  16   Internal worker function that returns the pointer to an EDK II Crypto
  17   Protocol/PPI.  The layout of the PPI, DXE Protocol, and SMM Protocol are
  18   identical which allows the implementation of the BaseCryptLib functions that
  19   call through a Protocol/PPI to be shared for the PEI, DXE, and SMM
  20   implementations.
  21
  22   This PEI implementation looks up the EDK II Crypto PPI and verifies the
  23   version each time a crypto service is called, so it is compatible with XIP
  24   PEIMs.
  25 **/
  26 VOID *
  27 GetCryptoServices (
  28   VOID
  29   )
  30 {
  31   EFI_STATUS        Status;
  32   EDKII_CRYPTO_PPI  *CryptoPpi;
  33   UINTN             Version;
  34
  35   CryptoPpi = NULL;
  36   Status    = PeiServicesLocatePpi (
  37                 &gEdkiiCryptoPpiGuid,
  38                 0,
  39                 NULL,
  40                 (VOID **)&CryptoPpi
  41                 );
  42   if (EFI_ERROR (Status) || (CryptoPpi == NULL)) {
  43     DEBUG ((DEBUG_ERROR, "[PeiCryptLib] Failed to locate Crypto PPI. Status = %r\n", Status));
  44     ASSERT_EFI_ERROR (Status);
  45     ASSERT (CryptoPpi != NULL);
  46     return NULL;
  47   }
  48
  49   Version = CryptoPpi->GetVersion ();
  50   if (Version < EDKII_CRYPTO_VERSION) {
  51     DEBUG ((DEBUG_ERROR, "[PeiCryptLib] Crypto PPI unsupported version %d\n", Version));
  52     ASSERT (Version >= EDKII_CRYPTO_VERSION);
  53     return NULL;
  54   }
  55
  56   return (VOID *)CryptoPpi;
  57 }