path: root/src/tpm2/PCR.c

/********************************************************************************/
/*										*/
/*			   PCR access and manipulation 				*/
/*			     Written by Ken Goldman				*/
/*		       IBM Thomas J. Watson Research Center			*/
/*            $Id: PCR.c 1658 2021-01-22 23:14:01Z kgoldman $			*/
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/* 8.7 PCR.c */
/* 8.7.1 Introduction */
/* This function contains the functions needed for PCR access and manipulation. */
/* This implementation uses a static allocation for the PCR. The amount of memory is allocated based
   on the number of PCR in the implementation and the number of implemented hash algorithms. This is
   not the expected implementation. PCR SPACE DEFINITIONS. */
/* In the definitions below, the g_hashPcrMap is a bit array that indicates which of the PCR are
   implemented. The g_hashPcr array is an array of digests. In this implementation, the space is
   allocated whether the PCR is implemented or not. */
/* 8.7.2 Includes, Defines, and Data Definitions */
#define PCR_C
#include "Tpm.h"
/* The initial value of PCR attributes.  The value of these fields should be consistent with PC
   Client specification In this implementation, we assume the total number of implemented PCR is
   24. */
static const PCR_Attributes s_initAttributes[] =
    {
	// PCR 0 - 15, static RTM
	{1, 0, 0x1F}, {1, 0, 0x1F}, {1, 0, 0x1F}, {1, 0, 0x1F},
	{1, 0, 0x1F}, {1, 0, 0x1F}, {1, 0, 0x1F}, {1, 0, 0x1F},
	{1, 0, 0x1F}, {1, 0, 0x1F}, {1, 0, 0x1F}, {1, 0, 0x1F},
	{1, 0, 0x1F}, {1, 0, 0x1F}, {1, 0, 0x1F}, {1, 0, 0x1F},
	{0, 0x0F, 0x1F},        // PCR 16, Debug
	{0, 0x10, 0x1C},        // PCR 17, Locality 4
	{0, 0x10, 0x1C},        // PCR 18, Locality 3
	{0, 0x10, 0x0C},        // PCR 19, Locality 2
	{0, 0x14, 0x0E},        // PCR 20, Locality 1
	{0, 0x14, 0x04},        // PCR 21, Dynamic OS
	{0, 0x14, 0x04},        // PCR 22, Dynamic OS
	{0, 0x0F, 0x1F},        // PCR 23, Application specific
	{0, 0x0F, 0x1F}         // PCR 24, testing policy
    };
/* 8.7.2 Functions */
/* 8.7.2.1 PCRBelongsAuthGroup() */
/* This function indicates if a PCR belongs to a group that requires an authValue in order to modify
   the PCR.  If it does, groupIndex is set to value of the group index.  This feature of PCR is
   decided by the platform specification. */
/* Return Type: BOOL */
/* TRUE: PCR belongs an authorization group */
/* FALSE: PCR does not belong an authorization group */
BOOL
PCRBelongsAuthGroup(
		    TPMI_DH_PCR      handle,        // IN: handle of PCR
		    UINT32          *groupIndex     // OUT: group index if PCR belongs a
		    //      group that allows authValue.  If PCR
		    //      does not belong to an authorization
		    //      group, the value in this parameter is
		    //      invalid
		    )
{
#if defined NUM_AUTHVALUE_PCR_GROUP && NUM_AUTHVALUE_PCR_GROUP > 0
    // Platform specification determines to which authorization group a PCR belongs
    // (if any). In this implementation, we assume there is only
    // one authorization group which contains PCR[20-22].  If the platform
    // specification requires differently, the implementation should be changed
    // accordingly
    if(handle >= 20 && handle <= 22)
	{
	    *groupIndex = 0;
	    return TRUE;
	}
#endif
    return FALSE;
}
/* 8.7.2.2 PCRBelongsPolicyGroup() */
/* This function indicates if a PCR belongs to a group that requires a policy authorization in order
   to modify the PCR.  If it does, groupIndex is set to value of the group index.  This feature of
   PCR is decided by the platform specification. */
/* Return Values Meaning */
/* TRUE: PCR belongs to a policy group */
/* FALSE: PCR does not belong to a policy group */
BOOL
PCRBelongsPolicyGroup(
		      TPMI_DH_PCR      handle,        // IN: handle of PCR
		      UINT32          *groupIndex     // OUT: group index if PCR belongs a group that
		      //     allows policy.  If PCR does not belong to
		      //     a policy group, the value in this
		      //     parameter is invalid
		      )
{
#if defined NUM_POLICY_PCR_GROUP && NUM_POLICY_PCR_GROUP > 0
    // Platform specification decides if a PCR belongs to a policy group and
    // belongs to which group.  In this implementation, we assume there is only
    // one policy group which contains PCR20-22.  If the platform specification
    // requires differently, the implementation should be changed accordingly
    if(handle >= 20 && handle <= 22)
	{
	    *groupIndex = 0;
	    return TRUE;
	}
#endif
    return FALSE;
}
/* 8.7.2.3 PCRBelongsTCBGroup() */
/* This function indicates if a PCR belongs to the TCB group. */
/* Return Values Meaning */
/* TRUE: PCR belongs to a TCB group */
/* FALSE: PCR does not belong to a TCB group */
static BOOL
PCRBelongsTCBGroup(
		   TPMI_DH_PCR      handle         // IN: handle of PCR
		   )
{
#if ENABLE_PCR_NO_INCREMENT == YES
#if 0
    // Platform specification decides if a PCR belongs to a TCB group.  In this
    // implementation, we assume PCR[20-22] belong to TCB group.  If the platform
    // specification requires differently, the implementation should be
    // changed accordingly
    if(handle >= 20 && handle <= 22)
	return TRUE;
#endif
    /* kgold - changed for PC Client, 16, 21-23 no increment */
    if ((handle == 16) ||
	((handle >= 21) && (handle <= 23))) {
	return  TRUE;
    }
#endif
    return FALSE;
}
/* 8.7.2.4 PCRPolicyIsAvailable() */
/* This function indicates if a policy is available for a PCR. */
/* Return Values Meaning */
/* TRUE the PCR may be authorized by policy */
/* FALSE the PCR does not allow policy */
BOOL
PCRPolicyIsAvailable(
		     TPMI_DH_PCR      handle         // IN: PCR handle
		     )
{
    UINT32          groupIndex;
    return PCRBelongsPolicyGroup(handle, &groupIndex);
}
/* 8.7.2.5 PCRGetAuthValue() */
/* This function is used to access the authValue of a PCR.  If PCR does not belong to an authValue
   group, an EmptyAuth() will be returned. */
TPM2B_AUTH *
PCRGetAuthValue(
		TPMI_DH_PCR      handle         // IN: PCR handle
		)
{
    UINT32      groupIndex;
    if(PCRBelongsAuthGroup(handle, &groupIndex))
	{
	    return &gc.pcrAuthValues.auth[groupIndex];
	}
    else
	{
	    return NULL;
	}
}
/* 8.7.2.6 PCRGetAuthPolicy() */
/* This function is used to access the authorization policy of a PCR. It sets policy to the
   authorization policy and returns the hash algorithm for policy If the PCR does not allow a
   policy, TPM_ALG_NULL is returned. */
TPMI_ALG_HASH
PCRGetAuthPolicy(
		 TPMI_DH_PCR      handle,        // IN: PCR handle
		 TPM2B_DIGEST    *policy         // OUT: policy of PCR
		 )
{
    UINT32           groupIndex;
    if(PCRBelongsPolicyGroup(handle, &groupIndex))
	{
	    *policy = gp.pcrPolicies.policy[groupIndex];
	    return gp.pcrPolicies.hashAlg[groupIndex];
	}
    else
	{
	    policy->t.size = 0;
	    return TPM_ALG_NULL;
	}
}
/* 8.7.2.7 PCRSimStart() */
/* This function is used to initialize the policies when a TPM is manufactured. This function would
   only be called in a manufacturing environment or in a TPM simulator. */
void
PCRSimStart(
	    void
	    )
{
    UINT32  i;
#if defined NUM_POLICY_PCR_GROUP && NUM_POLICY_PCR_GROUP > 0
    for(i = 0; i < NUM_POLICY_PCR_GROUP; i++)
	{
	    gp.pcrPolicies.hashAlg[i] = TPM_ALG_NULL;
	    gp.pcrPolicies.policy[i].t.size = 0;
	}
#endif
#if defined NUM_AUTHVALUE_PCR_GROUP && NUM_AUTHVALUE_PCR_GROUP > 0
    for(i = 0; i < NUM_AUTHVALUE_PCR_GROUP; i++)
	{
	    gc.pcrAuthValues.auth[i].t.size = 0;
	}
#endif
    // We need to give an initial configuration on allocated PCR before
    // receiving any TPM2_PCR_Allocate command to change this configuration
    // When the simulation environment starts, we allocate all the PCRs
    for(gp.pcrAllocated.count = 0; gp.pcrAllocated.count < HASH_COUNT;
	gp.pcrAllocated.count++)
	{
	    gp.pcrAllocated.pcrSelections[gp.pcrAllocated.count].hash
		= CryptHashGetAlgByIndex(gp.pcrAllocated.count);
	    gp.pcrAllocated.pcrSelections[gp.pcrAllocated.count].sizeofSelect
		= PCR_SELECT_MAX;
	    for(i = 0; i < PCR_SELECT_MAX; i++)
		gp.pcrAllocated.pcrSelections[gp.pcrAllocated.count].pcrSelect[i]
		    = 0xFF;
	}
    // Store the initial configuration to NV
    NV_SYNC_PERSISTENT(pcrPolicies);
    NV_SYNC_PERSISTENT(pcrAllocated);
    return;
}
/* 8.7.3.8 GetSavedPcrPointer() */
/* This function returns the address of an array of state saved PCR based on the hash algorithm. */
/* Return Values Meaning */
/* NULL no such algorithm */
/* not NULL pointer to the 0th byte of the 0th PCR */

static BYTE *
GetSavedPcrPointer(
		   TPM_ALG_ID       alg,           // IN: algorithm for bank
		   UINT32           pcrIndex       // IN: PCR index in PCR_SAVE
		   )
{
    BYTE            *retVal;
    switch(alg)
	{
#define HASH_CASE(HASH, Hash)						\
	    case TPM_ALG_##HASH:					\
	      retVal = gc.pcrSave.Hash[pcrIndex];			\
	      break;

	    FOR_EACH_HASH(HASH_CASE)
#undef HASH_CASE

	  default:
	    FAIL(FATAL_ERROR_INTERNAL);
	}
    return retVal;
}

/* 8.7.2.9 PcrIsAllocated() */
/* This function indicates if a PCR number for the particular hash algorithm is allocated. */
/* Return Values Meaning */
/* FALSE PCR is not allocated */
/* TRUE PCR is allocated */
BOOL
PcrIsAllocated(
	       UINT32           pcr,           // IN: The number of the PCR
	       TPMI_ALG_HASH    hashAlg        // IN: The PCR algorithm
	       )
{
    UINT32               i;
    BOOL                 allocated = FALSE;
    if(pcr < IMPLEMENTATION_PCR)
	{
	    for(i = 0; i < gp.pcrAllocated.count; i++)
		{
		    if(gp.pcrAllocated.pcrSelections[i].hash == hashAlg)
			{
			    if(((gp.pcrAllocated.pcrSelections[i].pcrSelect[pcr / 8])
				& (1 << (pcr % 8))) != 0)
				allocated = TRUE;
			    else
				allocated = FALSE;
			    break;
			}
		}
	}
    return allocated;
}
/* 8.7.3.10 GetPcrPointer() */
/* This function returns the address of an array of PCR based on the hash algorithm. */
/* Return Values Meaning */
/* NULL no such algorithm */
/* not NULL pointer to the 0th byte of the 0th PCR */

static BYTE *
GetPcrPointer(
	      TPM_ALG_ID       alg,           // IN: algorithm for bank
	      UINT32           pcrNumber      // IN: PCR number
	      )
{
    static BYTE     *pcr = NULL;

    if(!PcrIsAllocated(pcrNumber, alg))
	return NULL;
    switch(alg)
	{
#define HASH_CASE(HASH, Hash)						\
	    case TPM_ALG_##HASH:					\
	      pcr = s_pcrs[pcrNumber].Hash##Pcr;			\
	      break;

	    FOR_EACH_HASH(HASH_CASE)
#undef HASH_CASE

	  default:
	    FAIL(FATAL_ERROR_INTERNAL);
	    break;
	}
    return pcr;
}

/* 8.7.2.11 IsPcrSelected() */
/* This function indicates if an indicated PCR number is selected by the bit map in selection. */
/* Return Values Meaning */
/* FALSE PCR is not selected */
/* TRUE	PCR is selected */
static BOOL
IsPcrSelected(
	      UINT32               pcr,           // IN: The number of the PCR
	      TPMS_PCR_SELECTION  *selection      // IN: The selection structure
	      )
{
    BOOL                 selected;
    selected = (pcr < IMPLEMENTATION_PCR
		&& ((selection->pcrSelect[pcr / 8]) & (1 << (pcr % 8))) != 0);
    return selected;
}
/* 8.7.2.12 FilterPcr() */
/* This function modifies a PCR selection array based on the implemented PCR. */
static void
FilterPcr(
	  TPMS_PCR_SELECTION  *selection      // IN: input PCR selection
	  )
{
    UINT32     i;
    TPMS_PCR_SELECTION      *allocated = NULL;
    // If size of select is less than PCR_SELECT_MAX, zero the unspecified PCR
    for(i = selection->sizeofSelect; i < PCR_SELECT_MAX; i++)
	selection->pcrSelect[i] = 0;
    // Find the internal configuration for the bank
    for(i = 0; i < gp.pcrAllocated.count; i++)
	{
	    if(gp.pcrAllocated.pcrSelections[i].hash == selection->hash)
		{
		    allocated = &gp.pcrAllocated.pcrSelections[i];
		    break;
		}
	}
    for(i = 0; i < selection->sizeofSelect; i++)
	{
	    if(allocated == NULL)
		{
		    // If the required bank does not exist, clear input selection
		    selection->pcrSelect[i] = 0;
		}
	    else
		selection->pcrSelect[i] &= allocated->pcrSelect[i];
	}
    return;
}
/* 8.7.2.13 PcrDrtm() */
/* This function does the DRTM and H-CRTM processing it is called from _TPM_Hash_End(). */
void
PcrDrtm(
	const TPMI_DH_PCR        pcrHandle,     // IN: the index of the PCR to be
	//     modified
	const TPMI_ALG_HASH      hash,          // IN: the bank identifier
	const TPM2B_DIGEST      *digest         // IN: the digest to modify the PCR
	)
{
    BYTE        *pcrData = GetPcrPointer(hash, pcrHandle);
    if(pcrData != NULL)
	{
	    // Rest the PCR to zeros
	    MemorySet(pcrData, 0, digest->t.size);
	    // if the TPM has not started, then set the PCR to 0...04 and then extend
	    if(!TPMIsStarted())
		{
		    pcrData[digest->t.size - 1] = 4;
		}
	    // Now, extend the value
	    PCRExtend(pcrHandle, hash, digest->t.size, (BYTE *)digest->t.buffer);
	}
}
/* 8.7.2.14 PCR_ClearAuth() */
/* This function is used to reset the PCR authorization values. It is called on TPM2_Startup(CLEAR)
   and TPM2_Clear(). */
void
PCR_ClearAuth(
	      void
	      )
{
#if defined NUM_AUTHVALUE_PCR_GROUP && NUM_AUTHVALUE_PCR_GROUP > 0
    int         j;
    for(j = 0; j < NUM_AUTHVALUE_PCR_GROUP; j++)
	{
	    gc.pcrAuthValues.auth[j].t.size = 0;
	}
#endif
}
/* 8.7.2.15 PCRStartup() */
/* This function initializes the PCR subsystem at TPM2_Startup(). */
BOOL
PCRStartup(
	   STARTUP_TYPE     type,          // IN: startup type
	   BYTE             locality       // IN: startup locality
	   )
{
    UINT32              pcr, j;
    UINT32              saveIndex = 0;
    g_pcrReConfig = FALSE;
    // Don't test for SU_RESET because that should be the default when nothing
    // else is selected
    if(type != SU_RESUME && type != SU_RESTART)
	{
	    // PCR generation counter is cleared at TPM_RESET
	    gr.pcrCounter = 0;
	}
    // Initialize/Restore PCR values
    for(pcr = 0; pcr < IMPLEMENTATION_PCR; pcr++)
	{
	    // On resume, need to know if this PCR had its state saved or not
	    UINT32      stateSaved;
	    if(type == SU_RESUME
	       &&  s_initAttributes[pcr].stateSave == SET)
		{
		    stateSaved = 1;
		}
	    else
		{
		    stateSaved = 0;
		    PCRChanged(pcr);
		}
	    // If this is the H-CRTM PCR and we are not doing a resume and we
	    // had an H-CRTM event, then we don't change this PCR
	    if(pcr == HCRTM_PCR && type != SU_RESUME && g_DrtmPreStartup == TRUE)
		continue;
	    // Iterate each hash algorithm bank
	    for(j = 0; j < gp.pcrAllocated.count; j++)
		{
		    TPMI_ALG_HASH    hash = gp.pcrAllocated.pcrSelections[j].hash;
		    BYTE            *pcrData = GetPcrPointer(hash, pcr);
		    UINT16           pcrSize = CryptHashGetDigestSize(hash);
		    if(pcrData != NULL)
			{
			    // if state was saved
			    if(stateSaved == 1)
				{
				    // Restore saved PCR value
				    BYTE    *pcrSavedData;
				    pcrSavedData = GetSavedPcrPointer(
								      gp.pcrAllocated.pcrSelections[j].hash,
								      saveIndex);
				    if(pcrSavedData == NULL)
					return FALSE;
				    MemoryCopy(pcrData, pcrSavedData, pcrSize);
				}
			    else
				// PCR was not restored by state save
				{
				    // If the reset locality of the PCR is 4, then
				    // the reset value is all one's, otherwise it is
				    // all zero.
				    if((s_initAttributes[pcr].resetLocality & 0x10) != 0)
					MemorySet(pcrData, 0xFF, pcrSize);
				    else
					{
					    MemorySet(pcrData, 0, pcrSize);
					    if(pcr == HCRTM_PCR)
						pcrData[pcrSize - 1] = locality;
					}
				}
			}
		}
	    saveIndex += stateSaved;
	}
    // Reset authValues on TPM2_Startup(CLEAR)
    if(type != SU_RESUME)
	PCR_ClearAuth();
    return TRUE;
}
/* 8.7.2.16 PCRStateSave() */
/* This function is used to save the PCR values that will be restored on TPM Resume. */
void
PCRStateSave(
	     TPM_SU           type           // IN: startup type
	     )
{
    UINT32           pcr, j;
    UINT32           saveIndex = 0;
    // if state save CLEAR, nothing to be done.  Return here
    if(type == TPM_SU_CLEAR)
	return;
    // Copy PCR values to the structure that should be saved to NV
    for(pcr = 0; pcr < IMPLEMENTATION_PCR; pcr++)
	{
	    UINT32  stateSaved = (s_initAttributes[pcr].stateSave == SET) ? 1 : 0;
	    // Iterate each hash algorithm bank
	    for(j = 0; j < gp.pcrAllocated.count; j++)
		{
		    BYTE    *pcrData;
		    UINT32  pcrSize;
		    pcrData = GetPcrPointer(gp.pcrAllocated.pcrSelections[j].hash, pcr);
		    if(pcrData != NULL)
			{
			    pcrSize
				= CryptHashGetDigestSize(gp.pcrAllocated.pcrSelections[j].hash);
			    if(stateSaved == 1)
				{
				    // Restore saved PCR value
				    BYTE    *pcrSavedData;
				    pcrSavedData
					= GetSavedPcrPointer(gp.pcrAllocated.pcrSelections[j].hash,
							     saveIndex);
				    MemoryCopy(pcrSavedData, pcrData, pcrSize);
				}
			}
		}
	    saveIndex += stateSaved;
	}
    return;
}
/* 8.7.2.17 PCRIsStateSaved() */
/* This function indicates if the selected PCR is a PCR that is state saved on
   TPM2_Shutdown(STATE). The return value is based on PCR attributes. */
/* Return Values Meaning */
/* TRUE PCR is state saved */
/* FALSE PCR is not state saved */
BOOL
PCRIsStateSaved(
		TPMI_DH_PCR      handle         // IN: PCR handle to be extended
		)
{
    UINT32              pcr = handle - PCR_FIRST;
    if(s_initAttributes[pcr].stateSave == SET)
	return TRUE;
    else
	return FALSE;
}
/* 8.7.2.18 PCRIsResetAllowed() */
/* This function indicates if a PCR may be reset by the current command locality. The return value
   is based on PCR attributes, and not the PCR allocation. */
/* Return Values Meaning */
/* TRUE TPM2_PCR_Reset() is allowed */
/* FALSE TPM2_PCR_Reset() is not allowed */
BOOL
PCRIsResetAllowed(
		  TPMI_DH_PCR      handle         // IN: PCR handle to be extended
		  )
{
    UINT8               commandLocality;
    UINT8               localityBits = 1;
    UINT32              pcr = handle - PCR_FIRST;
    // Check for the locality
    commandLocality = _plat__LocalityGet();
#ifdef DRTM_PCR
    // For a TPM that does DRTM, Reset is not allowed at locality 4
    if(commandLocality == 4)
	return FALSE;
#endif
    localityBits = localityBits << commandLocality;
    if((localityBits & s_initAttributes[pcr].resetLocality) == 0)
	return FALSE;
    else
	return TRUE;
}
/* 8.7.2.19 PCRChanged() */
/* This function checks a PCR handle to see if the attributes for the PCR are set so that any change
   to the PCR causes an increment of the pcrCounter. If it does, then the function increments the
   counter. Will also bump the counter if the handle is zero which means that PCR 0 can not be in
   the TCB group. Bump on zero is used by TPM2_Clear(). */
void
PCRChanged(
	   TPM_HANDLE       pcrHandle      // IN: the handle of the PCR that changed.
	   )
{
    // For the reference implementation, the only change that does not cause
    // increment is a change to a PCR in the TCB group.
    if((pcrHandle == 0) || !PCRBelongsTCBGroup(pcrHandle))
	{
	    gr.pcrCounter++;
	    if(gr.pcrCounter == 0)
		FAIL(FATAL_ERROR_COUNTER_OVERFLOW);
	}
}
/* 8.7.2.20 PCRIsExtendAllowed() */
/* This function indicates a PCR may be extended at the current command locality. The return value
   is based on PCR attributes, and not the PCR allocation. */
/* Return Values Meaning */
/* TRUE extend is allowed */
/* FALSE extend is not allowed */
BOOL
PCRIsExtendAllowed(
		   TPMI_DH_PCR      handle         // IN: PCR handle to be extended
		   )
{
    UINT8               commandLocality;
    UINT8               localityBits = 1;
    UINT32              pcr = handle - PCR_FIRST;
    // Check for the locality
    commandLocality = _plat__LocalityGet();
    localityBits = localityBits << commandLocality;
    if((localityBits & s_initAttributes[pcr].extendLocality) == 0)
	return FALSE;
    else
	return TRUE;
}
/* 8.7.2.21 PCRExtend() */
/* This function is used to extend a PCR in a specific bank. */
void
PCRExtend(
	  TPMI_DH_PCR      handle,        // IN: PCR handle to be extended
	  TPMI_ALG_HASH    hash,          // IN: hash algorithm of PCR
	  UINT32           size,          // IN: size of data to be extended
	  BYTE            *data           // IN: data to be extended
	  )
{
    BYTE                *pcrData;
    HASH_STATE           hashState;
    UINT16               pcrSize;
    pcrData = GetPcrPointer(hash, handle - PCR_FIRST);
    // Extend PCR if it is allocated
    if(pcrData != NULL)
	{
	    pcrSize = CryptHashGetDigestSize(hash);
	    CryptHashStart(&hashState, hash);
	    CryptDigestUpdate(&hashState, pcrSize, pcrData);
	    CryptDigestUpdate(&hashState, size, data);
	    CryptHashEnd(&hashState, pcrSize, pcrData);
	    // PCR has changed so update the pcrCounter if necessary
	    PCRChanged(handle);
	}
    return;
}
/* 8.7.2.22 PCRComputeCurrentDigest() */
/* This function computes the digest of the selected PCR. */
/* As a side-effect, selection is modified so that only the implemented PCR will have their bits
   still set. */
void
PCRComputeCurrentDigest(
			TPMI_ALG_HASH        hashAlg,       // IN: hash algorithm to compute digest
			TPML_PCR_SELECTION  *selection,     // IN/OUT: PCR selection (filtered on
			//     output)
			TPM2B_DIGEST        *digest         // OUT: digest
			)
{
    HASH_STATE               hashState;
    TPMS_PCR_SELECTION      *select;
    BYTE                    *pcrData;   // will point to a digest
    UINT32                   pcrSize;
    UINT32                   pcr;
    UINT32                   i;
    // Initialize the hash
    digest->t.size = CryptHashStart(&hashState, hashAlg);
    pAssert(digest->t.size > 0 && digest->t.size < UINT16_MAX);
    // Iterate through the list of PCR selection structures
    for(i = 0; i < selection->count; i++)
	{
	    // Point to the current selection
	    select = &selection->pcrSelections[i]; // Point to the current selection
	    FilterPcr(select);      // Clear out the bits for unimplemented PCR
	    // Need the size of each digest
	    pcrSize = CryptHashGetDigestSize(selection->pcrSelections[i].hash);
	    // Iterate through the selection
	    for(pcr = 0; pcr < IMPLEMENTATION_PCR; pcr++)
		{
		    if(IsPcrSelected(pcr, select))         // Is this PCR selected
			{
			    // Get pointer to the digest data for the bank
			    pcrData = GetPcrPointer(selection->pcrSelections[i].hash, pcr);
			    pAssert(pcrData != NULL);
			    CryptDigestUpdate(&hashState, pcrSize, pcrData);  // add to digest
			}
		}
	}
    // Complete hash stack
    CryptHashEnd2B(&hashState, &digest->b);
    return;
}
/* 8.7.2.23 PCRRead() */
/* This function is used to read a list of selected PCR.  If the requested PCR number exceeds the
   maximum number that can be output, the selection is adjusted to reflect the actual output PCR. */
void
PCRRead(
	TPML_PCR_SELECTION  *selection,     // IN/OUT: PCR selection (filtered on
	//     output)
	TPML_DIGEST         *digest,        // OUT: digest
	UINT32              *pcrCounter     // OUT: the current value of PCR generation
	//     number
	)
{
    TPMS_PCR_SELECTION      *select;
    BYTE                    *pcrData;       // will point to a digest
    UINT32                   pcr;
    UINT32                   i;
    digest->count = 0;
    // Iterate through the list of PCR selection structures
    for(i = 0; i < selection->count; i++)
	{
	    // Point to the current selection
	    select = &selection->pcrSelections[i]; // Point to the current selection
	    FilterPcr(select);      // Clear out the bits for unimplemented PCR
	    // Iterate through the selection
	    for(pcr = 0; pcr < IMPLEMENTATION_PCR; pcr++)
		{
		    if(IsPcrSelected(pcr, select))         // Is this PCR selected
			{
			    // Check if number of digest exceed upper bound
			    if(digest->count > 7)
				{
				    // Clear rest of the current select bitmap
				    while(pcr < IMPLEMENTATION_PCR
					  // do not round up!
					  && (pcr / 8) < select->sizeofSelect)
					{
					    // do not round up!
					    select->pcrSelect[pcr / 8] &= (BYTE)~(1 << (pcr % 8));
					    pcr++;
					}
				    // Exit inner loop
				    break;
				}
			    // Need the size of each digest
			    digest->digests[digest->count].t.size =
				CryptHashGetDigestSize(selection->pcrSelections[i].hash);
			    // Get pointer to the digest data for the bank
			    pcrData = GetPcrPointer(selection->pcrSelections[i].hash, pcr);
			    pAssert(pcrData != NULL);
			    // Add to the data to digest
			    MemoryCopy(digest->digests[digest->count].t.buffer,
				       pcrData,
				       digest->digests[digest->count].t.size);
			    digest->count++;
			}
		}
	    // If we exit inner loop because we have exceed the output upper bound
	    if(digest->count > 7 && pcr < IMPLEMENTATION_PCR)
		{
		    // Clear rest of the selection
		    while(i < selection->count)
			{
			    MemorySet(selection->pcrSelections[i].pcrSelect, 0,
				      selection->pcrSelections[i].sizeofSelect);
			    i++;
			}
		    // exit outer loop
		    break;
		}
	}
    *pcrCounter = gr.pcrCounter;
    return;
}
/* 8.7.2.25 PCRAllocate() */
/* This function is used to change the PCR allocation. */
/* Error Returns Meaning */
/* TPM_RC_NO_RESULT allocate failed */
/* TPM_RC_PCR improper allocation */
TPM_RC
PCRAllocate(
	    TPML_PCR_SELECTION  *allocate,      // IN: required allocation
	    UINT32              *maxPCR,        // OUT: Maximum number of PCR
	    UINT32              *sizeNeeded,    // OUT: required space
	    UINT32              *sizeAvailable  // OUT: available space
	    )
{
    UINT32                  i, j, k;
    TPML_PCR_SELECTION      newAllocate;
    // Initialize the flags to indicate if HCRTM PCR and DRTM PCR are allocated.
    BOOL                    pcrHcrtm = FALSE;
    BOOL                    pcrDrtm = FALSE;
    // Create the expected new PCR allocation based on the existing allocation
    // and the new input:
    //  1. if a PCR bank does not appear in the new allocation, the existing
    //     allocation of this PCR bank will be preserved.
    //  2. if a PCR bank appears multiple times in the new allocation, only the
    //     last one will be in effect.
    newAllocate = gp.pcrAllocated;
    for(i = 0; i < allocate->count; i++)
	{
	    for(j = 0; j < newAllocate.count; j++)
		{
		    // If hash matches, the new allocation covers the old allocation
		    // for this particular bank.
		    // The assumption is the initial PCR allocation (from manufacture)
		    // has all the supported hash algorithms with an assigned bank
		    // (possibly empty).  So there must be a match for any new bank
		    // allocation from the input.
		    if(newAllocate.pcrSelections[j].hash ==
		       allocate->pcrSelections[i].hash)
			{
			    newAllocate.pcrSelections[j] = allocate->pcrSelections[i];
			    break;
			}
		}
	    // The j loop must exit with a match.
	    pAssert(j < newAllocate.count);
	}
    // Max PCR in a bank is MIN(implemented PCR, PCR with attributes defined)
    *maxPCR = sizeof(s_initAttributes) / sizeof(PCR_Attributes);
    if(*maxPCR > IMPLEMENTATION_PCR)
	*maxPCR = IMPLEMENTATION_PCR;
    // Compute required size for allocation
    *sizeNeeded = 0;
    for(i = 0; i < newAllocate.count; i++)
	{
	    UINT32      digestSize
		= CryptHashGetDigestSize(newAllocate.pcrSelections[i].hash);
#if defined(DRTM_PCR)
	    // Make sure that we end up with at least one DRTM PCR
	    pcrDrtm = pcrDrtm || TestBit(DRTM_PCR,
					 newAllocate.pcrSelections[i].pcrSelect,
					 newAllocate.pcrSelections[i].sizeofSelect);
#else   // if DRTM PCR is not required, indicate that the allocation is OK
	    pcrDrtm = TRUE;
#endif
#if defined(HCRTM_PCR)
	    // and one HCRTM PCR (since this is usually PCR 0...)
	    pcrHcrtm = pcrHcrtm || TestBit(HCRTM_PCR,
					   newAllocate.pcrSelections[i].pcrSelect,
					   newAllocate.pcrSelections[i].sizeofSelect);
#else
	    pcrHcrtm = TRUE;
#endif
	    for(j = 0; j < newAllocate.pcrSelections[i].sizeofSelect; j++)
		{
		    BYTE        mask = 1;
		    for(k = 0; k < 8; k++)
			{
			    if((newAllocate.pcrSelections[i].pcrSelect[j] & mask) != 0)
				*sizeNeeded += digestSize;
			    mask = mask << 1;
			}
		}
	}
    if(!pcrDrtm || !pcrHcrtm)
	return TPM_RC_PCR;
    // In this particular implementation, we always have enough space to
    // allocate PCR.  Different implementation may return a sizeAvailable less
    // than the sizeNeed.
    *sizeAvailable = sizeof(s_pcrs);
    // Save the required allocation to NV.  Note that after NV is written, the
    // PCR allocation in NV is no longer consistent with the RAM data
    // gp.pcrAllocated.  The NV version reflect the allocate after next
    // TPM_RESET, while the RAM version reflects the current allocation
    NV_WRITE_PERSISTENT(pcrAllocated, newAllocate);
    return TPM_RC_SUCCESS;
}
/* 8.7.2.26 PCRSetValue() */
/* This function is used to set the designated PCR in all banks to an initial value. The initial
   value is signed and will be sign extended into the entire PCR. */
void
PCRSetValue(
	    TPM_HANDLE       handle,        // IN: the handle of the PCR to set
	    INT8             initialValue   // IN: the value to set
	    )
{
    int              i;
    UINT32           pcr = handle - PCR_FIRST;
    TPMI_ALG_HASH    hash;
    UINT16           digestSize;
    BYTE            *pcrData;
    // Iterate supported PCR bank algorithms to reset
    for(i = 0; i < HASH_COUNT; i++)
	{
	    hash = CryptHashGetAlgByIndex(i);
	    // Prevent runaway
	    if(hash == TPM_ALG_NULL)
		break;
	    // Get a pointer to the data
	    pcrData = GetPcrPointer(gp.pcrAllocated.pcrSelections[i].hash, pcr);
	    // If the PCR is allocated
	    if(pcrData != NULL)
		{
		    // And the size of the digest
		    digestSize = CryptHashGetDigestSize(hash);
		    // Set the LSO to the input value
		    pcrData[digestSize - 1] = initialValue;
		    // Sign extend
		    if(initialValue >= 0)
			MemorySet(pcrData, 0, digestSize - 1);
		    else
			MemorySet(pcrData, -1, digestSize - 1);
		}
	}
}
/* 8.7.2.27 PCRResetDynamics */
/* This function is used to reset a dynamic PCR to 0.  This function is used in DRTM sequence. */
void
PCRResetDynamics(
		 void
		 )
{
    UINT32              pcr, i;
    // Initialize PCR values
    for(pcr = 0; pcr < IMPLEMENTATION_PCR; pcr++)
	{
	    // Iterate each hash algorithm bank
	    for(i = 0; i < gp.pcrAllocated.count; i++)
		{
		    BYTE    *pcrData;
		    UINT32  pcrSize;
		    pcrData = GetPcrPointer(gp.pcrAllocated.pcrSelections[i].hash, pcr);
		    if(pcrData != NULL)
			{
			    pcrSize =
				CryptHashGetDigestSize(gp.pcrAllocated.pcrSelections[i].hash);
			    // Reset PCR
			    // Any PCR can be reset by locality 4 should be reset to 0
			    if((s_initAttributes[pcr].resetLocality & 0x10) != 0)
				MemorySet(pcrData, 0, pcrSize);
			}
		}
	}
    return;
}
/* 8.7.2.28 PCRCapGetAllocation() */
/* This function is used to get the current allocation of PCR banks. */
/* Return Values Meaning */
/* YES: if the return count is 0 */
/* NO: if the return count is not 0 */
TPMI_YES_NO
PCRCapGetAllocation(
		    UINT32               count,         // IN: count of return
		    TPML_PCR_SELECTION  *pcrSelection   // OUT: PCR allocation list
		    )
{
    if(count == 0)
	{
	    pcrSelection->count = 0;
	    return YES;
	}
    else
	{
	    *pcrSelection = gp.pcrAllocated;
	    return NO;
	}
}
/* 8.7.2.29 PCRSetSelectBit() */
/* This function sets a bit in a bitmap array. */
static void
PCRSetSelectBit(
		UINT32           pcr,           // IN: PCR number
		BYTE            *bitmap         // OUT: bit map to be set
		)
{
    bitmap[pcr / 8] |= (1 << (pcr % 8));
    return;
}
/* 8.7.2.30 PCRGetProperty() */
/* This function returns the selected PCR property. */
/* Return Values Meaning */
/* TRUE the property type is implemented */
/* FALSE the property type is not implemented */
static BOOL
PCRGetProperty(
	       TPM_PT_PCR               property,
	       TPMS_TAGGED_PCR_SELECT  *select
	       )
{
    UINT32              pcr;
    UINT32              groupIndex;
    select->tag = property;
    // Always set the bitmap to be the size of all PCR
    select->sizeofSelect = (IMPLEMENTATION_PCR + 7) / 8;
    // Initialize bitmap
    MemorySet(select->pcrSelect, 0, select->sizeofSelect);
    // Collecting properties
    for(pcr = 0; pcr < IMPLEMENTATION_PCR; pcr++)
	{
	    switch(property)
		{
		  case TPM_PT_PCR_SAVE:
		    if(s_initAttributes[pcr].stateSave == SET)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_EXTEND_L0:
		    if((s_initAttributes[pcr].extendLocality & 0x01) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_RESET_L0:
		    if((s_initAttributes[pcr].resetLocality & 0x01) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_EXTEND_L1:
		    if((s_initAttributes[pcr].extendLocality & 0x02) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_RESET_L1:
		    if((s_initAttributes[pcr].resetLocality & 0x02) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_EXTEND_L2:
		    if((s_initAttributes[pcr].extendLocality & 0x04) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_RESET_L2:
		    if((s_initAttributes[pcr].resetLocality & 0x04) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_EXTEND_L3:
		    if((s_initAttributes[pcr].extendLocality & 0x08) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_RESET_L3:
		    if((s_initAttributes[pcr].resetLocality & 0x08) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_EXTEND_L4:
		    if((s_initAttributes[pcr].extendLocality & 0x10) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_RESET_L4:
		    if((s_initAttributes[pcr].resetLocality & 0x10) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
		  case TPM_PT_PCR_DRTM_RESET:
		    // DRTM reset PCRs are the PCR reset by locality 4
		    if((s_initAttributes[pcr].resetLocality & 0x10) != 0)
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
#if defined NUM_POLICY_PCR_GROUP && NUM_POLICY_PCR_GROUP > 0
		  case TPM_PT_PCR_POLICY:
		    if(PCRBelongsPolicyGroup(pcr + PCR_FIRST, &groupIndex))
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
#endif
#if defined NUM_AUTHVALUE_PCR_GROUP && NUM_AUTHVALUE_PCR_GROUP > 0
		  case TPM_PT_PCR_AUTH:
		    if(PCRBelongsAuthGroup(pcr + PCR_FIRST, &groupIndex))
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
#endif
#if ENABLE_PCR_NO_INCREMENT == YES
		  case TPM_PT_PCR_NO_INCREMENT:
		    if(PCRBelongsTCBGroup(pcr + PCR_FIRST))
			PCRSetSelectBit(pcr, select->pcrSelect);
		    break;
#endif
		  default:
		    // If property is not supported, stop scanning PCR attributes
		    // and return.
		    return FALSE;
		    break;
		}
	}
    return TRUE;
}
/* 8.7.2.31 PCRCapGetProperties() */
/* This function returns a list of PCR properties starting at property. */
/* Return Values Meaning */
/* YES: if no more property is available */
/* NO: if there are more properties not reported */
TPMI_YES_NO
PCRCapGetProperties(
		    TPM_PT_PCR                   property,      // IN: the starting PCR property
		    UINT32                       count,         // IN: count of returned properties
		    TPML_TAGGED_PCR_PROPERTY    *select         // OUT: PCR select
		    )
{
    TPMI_YES_NO     more = NO;
    UINT32          i;
    // Initialize output property list
    select->count = 0;
    // The maximum count of properties we may return is MAX_PCR_PROPERTIES
    if(count > MAX_PCR_PROPERTIES) count = MAX_PCR_PROPERTIES;
    // TPM_PT_PCR_FIRST is defined as 0 in spec.  It ensures that property
    // value would never be less than TPM_PT_PCR_FIRST
    cAssert(TPM_PT_PCR_FIRST == 0);
    // Iterate PCR properties. TPM_PT_PCR_LAST is the index of the last property
    // implemented on the TPM.
    for(i = property; i <= TPM_PT_PCR_LAST; i++)
	{
	    if(select->count < count)
		{
		    // If we have not filled up the return list, add more properties to it
		    if(PCRGetProperty(i, &select->pcrProperty[select->count]))
			// only increment if the property is implemented
			select->count++;
		}
	    else
		{
		    // If the return list is full but we still have properties
		    // available, report this and stop iterating.
		    more = YES;
		    break;
		}
	}
    return more;
}
/* 8.7.2.32 PCRCapGetHandles() */
/* This function is used to get a list of handles of PCR, started from handle. If handle exceeds the
   maximum PCR handle range, an empty list will be returned and the return value will be NO. */
/* Return Values Meaning */
/* YES if there are more handles available */
/* NO all the available handles has been returned */
TPMI_YES_NO
PCRCapGetHandles(
		 TPMI_DH_PCR      handle,        // IN: start handle
		 UINT32           count,         // IN: count of returned handles
		 TPML_HANDLE     *handleList     // OUT: list of handle
		 )
{
    TPMI_YES_NO     more = NO;
    UINT32          i;
    pAssert(HandleGetType(handle) == TPM_HT_PCR);
    // Initialize output handle list
    handleList->count = 0;
    // The maximum count of handles we may return is MAX_CAP_HANDLES
    if(count > MAX_CAP_HANDLES) count = MAX_CAP_HANDLES;
    // Iterate PCR handle range
    for(i = handle & HR_HANDLE_MASK; i <= PCR_LAST; i++)
	{
	    if(handleList->count < count)
		{
		    // If we have not filled up the return list, add this PCR
		    // handle to it
		    handleList->handle[handleList->count] = i + PCR_FIRST;
		    handleList->count++;
		}
	    else
		{
		    // If the return list is full but we still have PCR handle
		    // available, report this and stop iterating
		    more = YES;
		    break;
		}
	}
    return more;
}