system76-edk2/SecurityPkg/Library/Tpm2CommandLib/Tpm2Help.c

/** @file
  Implement TPM2 help.

Copyright (c) 2013 - 2014, Intel Corporation. All rights reserved. <BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution.  The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include <IndustryStandard/UefiTcgPlatform.h>
#include <Library/Tpm2CommandLib.h>
#include <Library/Tpm2DeviceLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>

typedef struct {
  TPMI_ALG_HASH              HashAlgo;
  UINT16                     HashSize;
} INTERNAL_HASH_INFO;

STATIC INTERNAL_HASH_INFO mHashInfo[] = {
  {TPM_ALG_SHA1,          SHA1_DIGEST_SIZE},
  {TPM_ALG_SHA256,        SHA256_DIGEST_SIZE},
  {TPM_ALG_SM3_256,       SM3_256_DIGEST_SIZE},
  {TPM_ALG_SHA384,        SHA384_DIGEST_SIZE},
  {TPM_ALG_SHA512,        SHA512_DIGEST_SIZE},
};

/**
  Return size of digest.

  @param[in] HashAlgo  Hash algorithm

  @return size of digest
**/
UINT16
EFIAPI
GetHashSizeFromAlgo (
  IN TPMI_ALG_HASH    HashAlgo
  )
{
  UINTN  Index;

  for (Index = 0; Index < sizeof(mHashInfo)/sizeof(mHashInfo[0]); Index++) {
    if (mHashInfo[Index].HashAlgo == HashAlgo) {
      return mHashInfo[Index].HashSize;
    }
  }
  return 0;
}

/**
  Copy AuthSessionIn to TPM2 command buffer.

  @param [in]  AuthSessionIn   Input AuthSession data
  @param [out] AuthSessionOut  Output AuthSession data in TPM2 command buffer

  @return AuthSession size
**/
UINT32
EFIAPI
CopyAuthSessionCommand (
  IN      TPMS_AUTH_COMMAND         *AuthSessionIn, OPTIONAL
  OUT     UINT8                     *AuthSessionOut
  )
{
  UINT8  *Buffer;

  Buffer = (UINT8 *)AuthSessionOut;
  
  //
  // Add in Auth session
  //
  if (AuthSessionIn != NULL) {
    //  sessionHandle
    WriteUnaligned32 ((UINT32 *)Buffer, SwapBytes32(AuthSessionIn->sessionHandle));
    Buffer += sizeof(UINT32);

    // nonce
    WriteUnaligned16 ((UINT16 *)Buffer, SwapBytes16 (AuthSessionIn->nonce.size));
    Buffer += sizeof(UINT16);

    CopyMem (Buffer, AuthSessionIn->nonce.buffer, AuthSessionIn->nonce.size);
    Buffer += AuthSessionIn->nonce.size;

    // sessionAttributes
    *(UINT8 *)Buffer = *(UINT8 *)&AuthSessionIn->sessionAttributes;
    Buffer++;

    // hmac
    WriteUnaligned16 ((UINT16 *)Buffer, SwapBytes16 (AuthSessionIn->hmac.size));
    Buffer += sizeof(UINT16);

    CopyMem (Buffer, AuthSessionIn->hmac.buffer, AuthSessionIn->hmac.size);
    Buffer += AuthSessionIn->hmac.size;
  } else {
    //  sessionHandle
    WriteUnaligned32 ((UINT32 *)Buffer, SwapBytes32(TPM_RS_PW));
    Buffer += sizeof(UINT32);

    // nonce = nullNonce
    WriteUnaligned16 ((UINT16 *)Buffer, SwapBytes16(0));
    Buffer += sizeof(UINT16);

    // sessionAttributes = 0
    *(UINT8 *)Buffer = 0x00;
    Buffer++;

    // hmac = nullAuth
    WriteUnaligned16 ((UINT16 *)Buffer, SwapBytes16(0));
    Buffer += sizeof(UINT16);
  }

  return (UINT32)(UINTN)(Buffer - (UINT8 *)AuthSessionOut);
}

/**
  Copy AuthSessionIn from TPM2 response buffer.

  @param [in]  AuthSessionIn   Input AuthSession data in TPM2 response buffer
  @param [out] AuthSessionOut  Output AuthSession data

  @return AuthSession size
**/
UINT32
EFIAPI
CopyAuthSessionResponse (
  IN      UINT8                      *AuthSessionIn,
  OUT     TPMS_AUTH_RESPONSE         *AuthSessionOut OPTIONAL
  )
{
  UINT8                      *Buffer;
  TPMS_AUTH_RESPONSE         LocalAuthSessionOut;

  if (AuthSessionOut == NULL) {
    AuthSessionOut = &LocalAuthSessionOut;
  }

  Buffer = (UINT8 *)AuthSessionIn;

  // nonce
  AuthSessionOut->nonce.size = SwapBytes16 (ReadUnaligned16 ((UINT16 *)Buffer));
  Buffer += sizeof(UINT16);

  CopyMem (AuthSessionOut->nonce.buffer, Buffer, AuthSessionOut->nonce.size);
  Buffer += AuthSessionOut->nonce.size;

  // sessionAttributes
  *(UINT8 *)&AuthSessionOut->sessionAttributes = *(UINT8 *)Buffer;
  Buffer++;

  // hmac
  AuthSessionOut->hmac.size = SwapBytes16 (ReadUnaligned16 ((UINT16 *)Buffer));
  Buffer += sizeof(UINT16);

  CopyMem (AuthSessionOut->hmac.buffer, Buffer, AuthSessionOut->hmac.size);
  Buffer += AuthSessionOut->hmac.size;

  return (UINT32)(UINTN)(Buffer - (UINT8 *)AuthSessionIn);
}