PcrValue.c

#include <Uefi.h>
#include <Library/UefiLib.h>
#include <Library/PrintLib.h>
#include <Library/BaseLib.h>
#include <Library/ShellCEntryLib.h>
#include <Library/ShellLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiBootServicesTableLib.h>

#include <Protocol/EfiShell.h>
#include <Protocol/LoadedImage.h>
#include <Protocol/TcgService.h>
#include <Protocol/Tcg2Protocol.h>
#include <IndustryStandard/UefiTcgPlatform.h>

#define EFI_TCG2_PROTOCOL_GUID \
  {0x607f766c, 0x7455, 0x42be, { 0x93, 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f }}

//VOID AsciiToUnicodeSize( CHAR8 *String, UINT8 length, CHAR16 *UniString);

VOID 
Dump_PcrDigest(OUT CHAR16* Buffer, 
               IN TPM_PCRINDEX PcrIndex, 
               IN TPM_PCRVALUE *PcrValue)
{
    int size = sizeof(TPM_PCRVALUE);
    UINT8 *buf = (UINT8 *)PcrValue;
    CHAR16 Convert[128];

    //Print(L"[%02d]  ", PcrIndex);
    for (int i = 0; i < size; i++) {
        UnicodeSPrint(Convert, sizeof(Convert), L"%02x", 0xff & buf[i]);
        //Print(L"%s ", Convert);
        //CopyMem ((VOID *)Buffer, (VOID*)Convert, Len);
        //Buffer += Len;
        StrCatS(Buffer, 4096, Convert);
    }
    StrCatS(Buffer, 4096, (CHAR16*)L"\n");
    //Print(L"\nPcrValue return: %s\n", Buffer);
}


BOOLEAN
CheckForTpm20()
{
     EFI_STATUS Status = EFI_SUCCESS;
     EFI_TCG2_PROTOCOL *Tcg2Protocol;
     EFI_GUID gEfiTcg2ProtocolGuid = EFI_TCG2_PROTOCOL_GUID;

     Status = gBS->LocateProtocol( &gEfiTcg2ProtocolGuid,
                                   NULL,
                                   (VOID **) &Tcg2Protocol);
     if (EFI_ERROR (Status)) {
         return FALSE;
     } 

     return TRUE;
}


EFI_STATUS
ExtractPcrValue(CHAR16 *Buffer)
{
    EFI_STATUS Status = EFI_SUCCESS;
    EFI_TCG_PROTOCOL *TcgProtocol;
    EFI_GUID gEfiTcgProtocolGuid = EFI_TCG_PROTOCOL_GUID;

    TPM_RSP_COMMAND_HDR *TpmRsp;
    UINT32              TpmSendSize;
    UINT8               CmdBuf[64];
    TPM_PCRINDEX        PcrIndex;
    TPM_PCRVALUE        *PcrValue;

    Status = gBS->LocateProtocol( &gEfiTcgProtocolGuid, 
                                  NULL, 
                                  (VOID **) &TcgProtocol);
    if (EFI_ERROR (Status)) {
        if (CheckForTpm20()) {
            Print(L"ERROR: Platform configured for TPM 2.0, not TPM 1.2\n");
        } else {
            Print(L"ERROR: Failed to locate EFI_TCG_PROTOCOL [%d]\n", Status);
        }
        return Status;
    }  


    // Loop through all the PCRs and print each digest 
    for (PcrIndex = 1; PcrIndex <= TPM_NUM_PCR; PcrIndex++) {
        TpmSendSize           = sizeof (TPM_RQU_COMMAND_HDR) + sizeof (UINT32);
        *(UINT16*)&CmdBuf[0]  = SwapBytes16 (TPM_TAG_RQU_COMMAND);
        *(UINT32*)&CmdBuf[2]  = SwapBytes32 (TpmSendSize);
        *(UINT32*)&CmdBuf[6]  = SwapBytes32 (TPM_ORD_PcrRead);
        *(UINT32*)&CmdBuf[10] = SwapBytes32 (PcrIndex);

        Status = TcgProtocol->PassThroughToTpm( TcgProtocol,
                                                TpmSendSize,
                                                CmdBuf,
                                                sizeof (CmdBuf),
                                                CmdBuf);
        if (EFI_ERROR (Status)) {
            if (CheckForTpm20()) {
                Print(L"ERROR: Platform configured for TPM 2.0, not TPM 1.2\n");
            } else {
                Print(L"ERROR: PassThroughToTpm failed [%d]\n", Status);
            }
            return Status;
        }

        TpmRsp = (TPM_RSP_COMMAND_HDR *) &CmdBuf[0];
        if ((TpmRsp->tag != SwapBytes16(TPM_TAG_RSP_COMMAND)) || (TpmRsp->returnCode != 0)) {
            Print(L"ERROR: TPM command result [%d]\n", SwapBytes16(TpmRsp->returnCode));
            return EFI_DEVICE_ERROR;
        }

        PcrValue = (TPM_PCRVALUE *) &CmdBuf[sizeof (TPM_RSP_COMMAND_HDR)];
        Dump_PcrDigest(Buffer, PcrIndex, PcrValue);
    }

    return Status;
}