1// This file was extracted from the TCG Published
2// Trusted Platform Module Library
3// Part 3: Commands
4// Family "2.0"
5// Level 00 Revision 01.16
6// October 30, 2014
7
8#include "InternalRoutines.h"
9#include "PolicyCpHash_fp.h"
10//
11//
12//     Error Returns                     Meaning
13//
14//     TPM_RC_CPHASH                     cpHash of policySession has previously been set to a different value
15//     TPM_RC_SIZE                       cpHashA is not the size of a digest produced by the hash algorithm
16//                                       associated with policySession
17//
18TPM_RC
19TPM2_PolicyCpHash(
20   PolicyCpHash_In       *in                   // IN: input parameter list
21   )
22{
23   SESSION      *session;
24   TPM_CC       commandCode = TPM_CC_PolicyCpHash;
25   HASH_STATE   hashState;
26
27// Input Validation
28
29   // Get pointer to the session structure
30   session = SessionGet(in->policySession);
31
32   // A new cpHash is given in input parameter, but cpHash in session context
33   // is not empty, or is not the same as the new cpHash
34   if(    in->cpHashA.t.size != 0
35       && session->u1.cpHash.t.size != 0
36       && !Memory2BEqual(&in->cpHashA.b, &session->u1.cpHash.b)
37      )
38       return TPM_RC_CPHASH;
39
40   // A valid cpHash must have the same size as session hash digest
41   if(in->cpHashA.t.size != CryptGetHashDigestSize(session->authHashAlg))
42       return TPM_RC_SIZE + RC_PolicyCpHash_cpHashA;
43
44// Internal Data Update
45
46   // Update policy hash
47   // policyDigestnew = hash(policyDigestold || TPM_CC_PolicyCpHash || cpHashA)
48   // Start hash
49   CryptStartHash(session->authHashAlg, &hashState);
50
51   // add old digest
52   CryptUpdateDigest2B(&hashState, &session->u2.policyDigest.b);
53
54   // add commandCode
55   CryptUpdateDigestInt(&hashState, sizeof(TPM_CC), &commandCode);
56
57   // add cpHashA
58   CryptUpdateDigest2B(&hashState, &in->cpHashA.b);
59
60   // complete the digest and get the results
61   CryptCompleteHash2B(&hashState, &session->u2.policyDigest.b);
62
63   // update cpHash in session context
64   session->u1.cpHash = in->cpHashA;
65   session->attributes.iscpHashDefined = SET;
66
67   return TPM_RC_SUCCESS;
68}
69