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 "HMAC_Start_fp.h"
37 
38 #if CC_HMAC_Start  // Conditional expansion of this file
39 
40 /*(See part 3 specification)
41 // Initialize a HMAC sequence and create a sequence object
42 */
43 //  Return Type: TPM_RC
44 //      TPM_RC_ATTRIBUTES       key referenced by 'handle' is not a signing key
45 //                              or is restricted
46 //      TPM_RC_OBJECT_MEMORY    no space to create an internal object
47 //      TPM_RC_KEY              key referenced by 'handle' is not an HMAC key
48 //      TPM_RC_VALUE            'hashAlg' is not compatible with the hash algorithm
49 //                              of the scheme of the object referenced by 'handle'
50 TPM_RC
TPM2_HMAC_Start(HMAC_Start_In * in,HMAC_Start_Out * out)51 TPM2_HMAC_Start(
52     HMAC_Start_In   *in,            // IN: input parameter list
53     HMAC_Start_Out  *out            // OUT: output parameter list
54     )
55 {
56     OBJECT                  *keyObject;
57     TPMT_PUBLIC             *publicArea;
58     TPM_ALG_ID               hashAlg;
59 
60 // Input Validation
61 
62     // Get HMAC key object and public area pointers
63     keyObject = HandleToObject(in->handle);
64     publicArea = &keyObject->publicArea;
65 
66     // Make sure that the key is an HMAC key
67     if(publicArea->type != TPM_ALG_KEYEDHASH)
68         return TPM_RCS_TYPE + RC_HMAC_Start_handle;
69 
70     // and that it is unrestricted
71     if(IS_ATTRIBUTE(publicArea->objectAttributes, TPMA_OBJECT, restricted))
72         return TPM_RCS_ATTRIBUTES + RC_HMAC_Start_handle;
73 
74     // and that it is a signing key
75     if(!IS_ATTRIBUTE(publicArea->objectAttributes, TPMA_OBJECT, sign))
76         return TPM_RCS_KEY + RC_HMAC_Start_handle;
77 
78     // See if the key has a default
79     if(publicArea->parameters.keyedHashDetail.scheme.scheme == TPM_ALG_NULL)
80         // it doesn't so use the input value
81         hashAlg = in->hashAlg;
82     else
83     {
84         // key has a default so use it
85         hashAlg
86             = publicArea->parameters.keyedHashDetail.scheme.details.hmac.hashAlg;
87         // and verify that the input was either the  TPM_ALG_NULL or the default
88         if(in->hashAlg != TPM_ALG_NULL && in->hashAlg != hashAlg)
89             hashAlg = TPM_ALG_NULL;
90     }
91     // if we ended up without a hash algorithm then return an error
92     if(hashAlg == TPM_ALG_NULL)
93         return TPM_RCS_VALUE + RC_HMAC_Start_hashAlg;
94 
95 // Internal Data Update
96 
97     // Create a HMAC sequence object. A TPM_RC_OBJECT_MEMORY error may be
98     // returned at this point
99     return ObjectCreateHMACSequence(hashAlg,
100                                     keyObject,
101                                     &in->auth,
102                                     &out->sequenceHandle);
103 }
104 
105 #endif // CC_HMAC_Start