SecurityPkg: Debug code to audit BIOS TPM extend operations

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2858

In V2: Fixed patch format and uncrustify cleanup

In V1: Add debug functionality to examine TPM extend operations
performed by BIOS and inspect the PCR 00 value prior to
any BIOS measurements.

Signed-off-by: Rodrigo Gonzalez del Cueto <rodrigo.gonzalez.del.cueto@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

1 files changed, 189 insertions, 1 deletions

diff --git a/SecurityPkg/Library/Tpm2CommandLib/Tpm2Integrity.c b/SecurityPkg/Library/Tpm2CommandLib/Tpm2Integrity.c
index 8dde5f34a2..94e93b2642 100644
--- a/SecurityPkg/Library/Tpm2CommandLib/Tpm2Integrity.c
+++ b/SecurityPkg/Library/Tpm2CommandLib/Tpm2Integrity.c
@@ -1,7 +1,7 @@
 /** @file

   Implement TPM2 Integrity related command.

 

-Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved. <BR>

+Copyright (c) 2013 - 2021, Intel Corporation. All rights reserved. <BR>

 SPDX-License-Identifier: BSD-2-Clause-Patent

 

 **/

@@ -138,6 +138,23 @@ Tpm2PcrExtend (
       &Digests->digests[Index].digest,

       DigestSize

       );

+

+    DEBUG_CODE_BEGIN ();

+    UINTN  Index2;

+    DEBUG ((

+      DEBUG_VERBOSE,

+      "Tpm2PcrExtend - Hash = 0x%04x, Pcr[%02d], digest = ",

+      Digests->digests[Index].hashAlg,

+      (UINT8)PcrHandle

+      ));

+

+    for (Index2 = 0; Index2 < DigestSize; Index2++) {

+      DEBUG ((DEBUG_VERBOSE, "%02x ", Buffer[Index2]));

+    }

+

+    DEBUG ((DEBUG_VERBOSE, "\n"));

+    DEBUG_CODE_END ();

+

     Buffer += DigestSize;

   }

 

@@ -172,6 +189,11 @@ Tpm2PcrExtend (
     return EFI_DEVICE_ERROR;

   }

 

+  DEBUG_CODE_BEGIN ();

+  DEBUG ((DEBUG_VERBOSE, "Tpm2PcrExtend: PCR read after extend...\n"));

+  Tpm2PcrReadForActiveBank (PcrHandle, NULL);

+  DEBUG_CODE_END ();

+

   //

   // Unmarshal the response

   //

@@ -705,3 +727,169 @@ Done:
   ZeroMem (&LocalAuthSession.hmac, sizeof (LocalAuthSession.hmac));

   return Status;

 }

+

+/**

+   This function will query the TPM to determine which hashing algorithms and

+   get the digests of all active and supported PCR banks of a specific PCR register.

+

+   @param[in]     PcrHandle     The index of the PCR register to be read.

+   @param[out]    HashList      List of digests from PCR register being read.

+

+   @retval EFI_SUCCESS           The Pcr was read successfully.

+   @retval EFI_DEVICE_ERROR      The command was unsuccessful.

+**/

+EFI_STATUS

+EFIAPI

+Tpm2PcrReadForActiveBank (

+  IN      TPMI_DH_PCR  PcrHandle,

+  OUT     TPML_DIGEST  *HashList

+  )

+{

+  EFI_STATUS          Status;

+  TPML_PCR_SELECTION  Pcrs;

+  TPML_PCR_SELECTION  PcrSelectionIn;

+  TPML_PCR_SELECTION  PcrSelectionOut;

+  TPML_DIGEST         PcrValues;

+  UINT32              PcrUpdateCounter;

+  UINT8               PcrIndex;

+  UINT32              TpmHashAlgorithmBitmap;

+  TPMI_ALG_HASH       CurrentPcrBankHash;

+  UINT32              ActivePcrBanks;

+  UINT32              TcgRegistryHashAlg;

+  UINTN               Index;

+  UINTN               Index2;

+

+  PcrIndex = (UINT8)PcrHandle;

+

+  if ((PcrIndex < 0) ||

+      (PcrIndex >= IMPLEMENTATION_PCR))

+  {

+    return EFI_INVALID_PARAMETER;

+  }

+

+  ZeroMem (&PcrSelectionIn, sizeof (PcrSelectionIn));

+  ZeroMem (&PcrUpdateCounter, sizeof (UINT32));

+  ZeroMem (&PcrSelectionOut, sizeof (PcrSelectionOut));

+  ZeroMem (&PcrValues, sizeof (PcrValues));

+  ZeroMem (&Pcrs, sizeof (TPML_PCR_SELECTION));

+

+  DEBUG ((DEBUG_INFO, "ReadPcr - %02d\n", PcrIndex));

+

+  //

+  // Read TPM capabilities

+  //

+  Status = Tpm2GetCapabilityPcrs (&Pcrs);

+

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "ReadPcr: Unable to read TPM capabilities\n"));

+    return EFI_DEVICE_ERROR;

+  }

+

+  //

+  // Get Active Pcrs

+  //

+  Status = Tpm2GetCapabilitySupportedAndActivePcrs (

+             &TpmHashAlgorithmBitmap,

+             &ActivePcrBanks

+             );

+

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "ReadPcr: Unable to read TPM capabilities and active PCRs\n"));

+    return EFI_DEVICE_ERROR;

+  }

+

+  //

+  // Select from Active PCRs

+  //

+  for (Index = 0; Index < Pcrs.count; Index++) {

+    CurrentPcrBankHash = Pcrs.pcrSelections[Index].hash;

+

+    switch (CurrentPcrBankHash) {

+      case TPM_ALG_SHA1:

+        DEBUG ((DEBUG_VERBOSE, "HASH_ALG_SHA1 Present\n"));

+        TcgRegistryHashAlg = HASH_ALG_SHA1;

+        break;

+      case TPM_ALG_SHA256:

+        DEBUG ((DEBUG_VERBOSE, "HASH_ALG_SHA256 Present\n"));

+        TcgRegistryHashAlg = HASH_ALG_SHA256;

+        break;

+      case TPM_ALG_SHA384:

+        DEBUG ((DEBUG_VERBOSE, "HASH_ALG_SHA384 Present\n"));

+        TcgRegistryHashAlg = HASH_ALG_SHA384;

+        break;

+      case TPM_ALG_SHA512:

+        DEBUG ((DEBUG_VERBOSE, "HASH_ALG_SHA512 Present\n"));

+        TcgRegistryHashAlg = HASH_ALG_SHA512;

+        break;

+      case TPM_ALG_SM3_256:

+        DEBUG ((DEBUG_VERBOSE, "HASH_ALG_SM3 Present\n"));

+        TcgRegistryHashAlg = HASH_ALG_SM3_256;

+        break;

+      default:

+        //

+        // Unsupported algorithm

+        //

+        DEBUG ((DEBUG_VERBOSE, "Unknown algorithm present\n"));

+        TcgRegistryHashAlg = 0;

+        break;

+    }

+

+    //

+    // Skip unsupported and inactive PCR banks

+    //

+    if ((TcgRegistryHashAlg & ActivePcrBanks) == 0) {

+      DEBUG ((DEBUG_VERBOSE, "Skipping unsupported or inactive bank: 0x%04x\n", CurrentPcrBankHash));

+      continue;

+    }

+

+    //

+    // Select PCR from current active bank

+    //

+    PcrSelectionIn.pcrSelections[PcrSelectionIn.count].hash         = Pcrs.pcrSelections[Index].hash;

+    PcrSelectionIn.pcrSelections[PcrSelectionIn.count].sizeofSelect = PCR_SELECT_MAX;

+    PcrSelectionIn.pcrSelections[PcrSelectionIn.count].pcrSelect[0] = (PcrIndex < 8) ? 1 << PcrIndex : 0;

+    PcrSelectionIn.pcrSelections[PcrSelectionIn.count].pcrSelect[1] = (PcrIndex > 7) && (PcrIndex < 16) ? 1 << (PcrIndex - 8) : 0;

+    PcrSelectionIn.pcrSelections[PcrSelectionIn.count].pcrSelect[2] = (PcrIndex > 15) ? 1 << (PcrIndex - 16) : 0;

+    PcrSelectionIn.count++;

+  }

+

+  //

+  // Read PCRs

+  //

+  Status = Tpm2PcrRead (

+             &PcrSelectionIn,

+             &PcrUpdateCounter,

+             &PcrSelectionOut,

+             &PcrValues

+             );

+

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "Tpm2PcrRead failed Status = %r \n", Status));

+    return EFI_DEVICE_ERROR;

+  }

+

+  for (Index = 0; Index < PcrValues.count; Index++) {

+    DEBUG ((

+      DEBUG_INFO,

+      "ReadPcr - HashAlg = 0x%04x, Pcr[%02d], digest = ",

+      PcrSelectionOut.pcrSelections[Index].hash,

+      PcrIndex

+      ));

+

+    for (Index2 = 0; Index2 < PcrValues.digests[Index].size; Index2++) {

+      DEBUG ((DEBUG_INFO, "%02x ", PcrValues.digests[Index].buffer[Index2]));

+    }

+

+    DEBUG ((DEBUG_INFO, "\n"));

+  }

+

+  if (HashList != NULL) {

+    CopyMem (

+      HashList,

+      &PcrValues,

+      sizeof (TPML_DIGEST)

+      );

+  }

+

+  return EFI_SUCCESS;

+}