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 "PolicyPCR_fp.h"
10 //
11 //
12 // Error Returns Meaning
13 //
14 // TPM_RC_VALUE if provided, pcrDigest does not match the current PCR settings
15 // TPM_RC_PCR_CHANGED a previous TPM2_PolicyPCR() set pcrCounter and it has changed
16 //
17 TPM_RC
TPM2_PolicyPCR(PolicyPCR_In * in)18 TPM2_PolicyPCR(
19 PolicyPCR_In *in // IN: input parameter list
20 )
21 {
22 SESSION *session;
23 TPM2B_DIGEST pcrDigest;
24 BYTE pcrs[sizeof(TPML_PCR_SELECTION)];
25 UINT32 pcrSize;
26 BYTE *buffer;
27 INT32 bufferSize;
28 TPM_CC commandCode = TPM_CC_PolicyPCR;
29 HASH_STATE hashState;
30
31 // Input Validation
32
33 // Get pointer to the session structure
34 session = SessionGet(in->policySession);
35
36 // Do validation for non trial session
37 if(session->attributes.isTrialPolicy == CLEAR)
38 {
39 // Make sure that this is not going to invalidate a previous PCR check
40 if(session->pcrCounter != 0 && session->pcrCounter != gr.pcrCounter)
41 return TPM_RC_PCR_CHANGED;
42
43 // Compute current PCR digest
44 PCRComputeCurrentDigest(session->authHashAlg, &in->pcrs, &pcrDigest);
45
46 // If the caller specified the PCR digest and it does not
47 // match the current PCR settings, return an error..
48 if(in->pcrDigest.t.size != 0)
49 {
50 if(!Memory2BEqual(&in->pcrDigest.b, &pcrDigest.b))
51 return TPM_RC_VALUE + RC_PolicyPCR_pcrDigest;
52 }
53 }
54 else
55 {
56 // For trial session, just use the input PCR digest
57 pcrDigest = in->pcrDigest;
58 }
59 // Internal Data Update
60
61 // Update policy hash
62 // policyDigestnew = hash( policyDigestold || TPM_CC_PolicyPCR
63 // || pcrs || pcrDigest)
64 // Start hash
65 CryptStartHash(session->authHashAlg, &hashState);
66
67 // add old digest
68 CryptUpdateDigest2B(&hashState, &session->u2.policyDigest.b);
69
70 // add commandCode
71 CryptUpdateDigestInt(&hashState, sizeof(TPM_CC), &commandCode);
72
73 // add PCRS
74 buffer = pcrs;
75 bufferSize = sizeof(TPML_PCR_SELECTION);
76 pcrSize = TPML_PCR_SELECTION_Marshal(&in->pcrs, &buffer, &bufferSize);
77 CryptUpdateDigest(&hashState, pcrSize, pcrs);
78
79 // add PCR digest
80 CryptUpdateDigest2B(&hashState, &pcrDigest.b);
81
82 // complete the hash and get the results
83 CryptCompleteHash2B(&hashState, &session->u2.policyDigest.b);
84
85 // update pcrCounter in session context for non trial session
86 if(session->attributes.isTrialPolicy == CLEAR)
87 {
88 session->pcrCounter = gr.pcrCounter;
89 }
90
91 return TPM_RC_SUCCESS;
92 }
93