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 #include "ChangeEPS_fp.h"
37 
38 #if CC_ChangeEPS  // Conditional expansion of this file
39 
40 /*(See part 3 specification)
41 // Reset current EPS value
42 */
43 TPM_RC
TPM2_ChangeEPS(ChangeEPS_In * in)44 TPM2_ChangeEPS(
45     ChangeEPS_In    *in             // IN: input parameter list
46     )
47 {
48     // The command needs NV update.  Check if NV is available.
49     // A TPM_RC_NV_UNAVAILABLE or TPM_RC_NV_RATE error may be returned at
50     // this point
51     RETURN_IF_NV_IS_NOT_AVAILABLE;
52 
53     // Input parameter is not reference in command action
54     NOT_REFERENCED(in);
55 
56 // Internal Data Update
57 
58     // Reset endorsement hierarchy seed from RNG
59     CryptRandomGenerate(sizeof(gp.EPSeed.t.buffer), gp.EPSeed.t.buffer);
60 
61     // Create new ehProof value from RNG
62     CryptRandomGenerate(sizeof(gp.ehProof.t.buffer), gp.ehProof.t.buffer);
63 
64     // Enable endorsement hierarchy
65     gc.ehEnable = TRUE;
66 
67     // set authValue buffer to zeros
68     MemorySet(gp.endorsementAuth.t.buffer, 0, gp.endorsementAuth.t.size);
69     // Set endorsement authValue to null
70     gp.endorsementAuth.t.size = 0;
71 
72     // Set endorsement authPolicy to null
73     gp.endorsementAlg = TPM_ALG_NULL;
74     gp.endorsementPolicy.t.size = 0;
75 
76     // Flush loaded object in endorsement hierarchy
77     ObjectFlushHierarchy(TPM_RH_ENDORSEMENT);
78 
79     // Flush evict object of endorsement hierarchy stored in NV
80     NvFlushHierarchy(TPM_RH_ENDORSEMENT);
81 
82     // Save hierarchy changes to NV
83     NV_SYNC_PERSISTENT(EPSeed);
84     NV_SYNC_PERSISTENT(ehProof);
85     NV_SYNC_PERSISTENT(endorsementAuth);
86     NV_SYNC_PERSISTENT(endorsementAlg);
87     NV_SYNC_PERSISTENT(endorsementPolicy);
88 
89     // orderly state should be cleared because of the update to state clear data
90     g_clearOrderly = TRUE;
91 
92     return TPM_RC_SUCCESS;
93 }
94 
95 #endif // CC_ChangeEPS