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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 "PolicyTicket_fp.h"
37 
38 #if CC_PolicyTicket  // Conditional expansion of this file
39 
40 #include "Policy_spt_fp.h"
41 
42 /*(See part 3 specification)
43 // Include ticket to the policy evaluation
44 */
45 //  Return Type: TPM_RC
46 //      TPM_RC_CPHASH           policy's cpHash was previously set to a different
47 //                              value
48 //      TPM_RC_EXPIRED          'timeout' value in the ticket is in the past and the
49 //                              ticket has expired
50 //      TPM_RC_SIZE             'timeout' or 'cpHash' has invalid size for the
51 //      TPM_RC_TICKET           'ticket' is not valid
52 TPM_RC
TPM2_PolicyTicket(PolicyTicket_In * in)53 TPM2_PolicyTicket(
54     PolicyTicket_In     *in             // IN: input parameter list
55     )
56 {
57     TPM_RC                   result;
58     SESSION                 *session;
59     UINT64                   authTimeout;
60     TPMT_TK_AUTH             ticketToCompare;
61     TPM_CC                   commandCode = TPM_CC_PolicySecret;
62     BOOL                     expiresOnReset;
63 
64 // Input Validation
65 
66     // Get pointer to the session structure
67     session = SessionGet(in->policySession);
68 
69     // NOTE: A trial policy session is not allowed to use this command.
70     // A ticket is used in place of a previously given authorization. Since
71     // a trial policy doesn't actually authenticate, the validated
72     // ticket is not necessary and, in place of using a ticket, one
73     // should use the intended authorization for which the ticket
74     // would be a substitute.
75     if(session->attributes.isTrialPolicy)
76         return TPM_RCS_ATTRIBUTES + RC_PolicyTicket_policySession;
77     // Restore timeout data.  The format of timeout buffer is TPM-specific.
78     // In this implementation, the most significant bit of the timeout value is
79     // used as the flag to indicate that the ticket expires on TPM Reset or
80     // TPM Restart. The flag has to be removed before the parameters and ticket
81     // are checked.
82     if(in->timeout.t.size != sizeof(UINT64))
83         return TPM_RCS_SIZE + RC_PolicyTicket_timeout;
84     authTimeout = BYTE_ARRAY_TO_UINT64(in->timeout.t.buffer);
85 
86     // extract the flag
87     expiresOnReset = (authTimeout & EXPIRATION_BIT) != 0;
88     authTimeout &= ~EXPIRATION_BIT;
89 
90     // Do the normal checks on the cpHashA and timeout values
91     result = PolicyParameterChecks(session, authTimeout,
92                                    &in->cpHashA,
93                                    NULL,                    // no nonce
94                                    0,                       // no bad nonce return
95                                    RC_PolicyTicket_cpHashA,
96                                    RC_PolicyTicket_timeout);
97     if(result != TPM_RC_SUCCESS)
98         return result;
99     // Validate Ticket
100     // Re-generate policy ticket by input parameters
101     TicketComputeAuth(in->ticket.tag, in->ticket.hierarchy,
102                       authTimeout, expiresOnReset, &in->cpHashA, &in->policyRef,
103                       &in->authName, &ticketToCompare);
104     // Compare generated digest with input ticket digest
105     if(!MemoryEqual2B(&in->ticket.digest.b, &ticketToCompare.digest.b))
106         return TPM_RCS_TICKET + RC_PolicyTicket_ticket;
107 
108 // Internal Data Update
109 
110     // Is this ticket to take the place of a TPM2_PolicySigned() or
111     // a TPM2_PolicySecret()?
112     if(in->ticket.tag == TPM_ST_AUTH_SIGNED)
113         commandCode = TPM_CC_PolicySigned;
114     else if(in->ticket.tag == TPM_ST_AUTH_SECRET)
115         commandCode = TPM_CC_PolicySecret;
116     else
117         // There could only be two possible tag values.  Any other value should
118         // be caught by the ticket validation process.
119         FAIL(FATAL_ERROR_INTERNAL);
120 
121     // Update policy context
122     PolicyContextUpdate(commandCode, &in->authName, &in->policyRef,
123                         &in->cpHashA, authTimeout, session);
124 
125     return TPM_RC_SUCCESS;
126 }
127 
128 #endif // CC_PolicyTicket