1 /* Microsoft Reference Implementation for TPM 2.0
2  *
3  *  The copyright in this software is being made available under the BSD License,
4  *  included below. This software may be subject to other third party and
5  *  contributor rights, including patent rights, and no such rights are granted
6  *  under this license.
7  *
8  *  Copyright (c) Microsoft Corporation
9  *
10  *  All rights reserved.
11  *
12  *  BSD License
13  *
14  *  Redistribution and use in source and binary forms, with or without modification,
15  *  are permitted provided that the following conditions are met:
16  *
17  *  Redistributions of source code must retain the above copyright notice, this list
18  *  of conditions and the following disclaimer.
19  *
20  *  Redistributions in binary form must reproduce the above copyright notice, this
21  *  list of conditions and the following disclaimer in the documentation and/or
22  *  other materials provided with the distribution.
23  *
24  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ""AS IS""
25  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27  *  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
28  *  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
29  *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30  *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
31  *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 #include "Tpm.h"
36 
37 // This function is called to process a _TPM_Hash_End indication.
38 LIB_EXPORT void
_TPM_Hash_End(void)39 _TPM_Hash_End(
40     void
41     )
42 {
43     UINT32          i;
44     TPM2B_DIGEST    digest;
45     HASH_OBJECT    *hashObject;
46     TPMI_DH_PCR     pcrHandle;
47 
48     // If the DRTM handle is not being used, then either _TPM_Hash_Start has not
49     // been called, _TPM_Hash_End was previously called, or some other command
50     // was executed and the sequence was aborted.
51     if(g_DRTMHandle == TPM_RH_UNASSIGNED)
52         return;
53 
54     // Get DRTM sequence object
55     hashObject = (HASH_OBJECT *)HandleToObject(g_DRTMHandle);
56 
57     // Is this _TPM_Hash_End after Startup or before
58     if(TPMIsStarted())
59     {
60         // After
61 
62         // Reset the DRTM PCR
63         PCRResetDynamics();
64 
65         // Extend the DRTM_PCR.
66         pcrHandle = PCR_FIRST + DRTM_PCR;
67 
68         // DRTM sequence increments restartCount
69         gr.restartCount++;
70     }
71     else
72     {
73         pcrHandle = PCR_FIRST + HCRTM_PCR;
74         g_DrtmPreStartup = TRUE;
75     }
76 
77     // Complete hash and extend PCR, or if this is an HCRTM, complete
78     // the hash, reset the H-CRTM register (PCR[0]) to 0...04, and then
79     // extend the H-CRTM data
80     for(i = 0; i < HASH_COUNT; i++)
81     {
82         TPMI_ALG_HASH       hash = CryptHashGetAlgByIndex(i);
83         // make sure that the PCR is implemented for this algorithm
84         if(PcrIsAllocated(pcrHandle,
85                           hashObject->state.hashState[i].hashAlg))
86         {
87             // Complete hash
88             digest.t.size = CryptHashGetDigestSize(hash);
89             CryptHashEnd2B(&hashObject->state.hashState[i], &digest.b);
90 
91             PcrDrtm(pcrHandle, hash, &digest);
92         }
93     }
94 
95     // Flush sequence object.
96     FlushObject(g_DRTMHandle);
97 
98     g_DRTMHandle = TPM_RH_UNASSIGNED;
99 
100 
101     return;
102 }