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_fp.h"
37
38 #if CC_HMAC // Conditional expansion of this file
39
40 /*(See part 3 specification)
41 // Compute HMAC on a data buffer
42 */
43 // Return Type: TPM_RC
44 // TPM_RC_ATTRIBUTES key referenced by 'handle' is a restricted key
45 // TPM_RC_KEY 'handle' does not reference a signing key
46 // TPM_RC_TYPE key referenced by 'handle' is not an HMAC key
47 // TPM_RC_VALUE 'hashAlg' is not compatible with the hash algorithm
48 // of the scheme of the object referenced by 'handle'
49 TPM_RC
TPM2_HMAC(HMAC_In * in,HMAC_Out * out)50 TPM2_HMAC(
51 HMAC_In *in, // IN: input parameter list
52 HMAC_Out *out // OUT: output parameter list
53 )
54 {
55 HMAC_STATE hmacState;
56 OBJECT *hmacObject;
57 TPMI_ALG_HASH hashAlg;
58 TPMT_PUBLIC *publicArea;
59
60 // Input Validation
61
62 // Get HMAC key object and public area pointers
63 hmacObject = HandleToObject(in->handle);
64 publicArea = &hmacObject->publicArea;
65 // Make sure that the key is an HMAC key
66 if(publicArea->type != TPM_ALG_KEYEDHASH)
67 return TPM_RCS_TYPE + RC_HMAC_handle;
68
69 // and that it is unrestricted
70 if(IS_ATTRIBUTE(publicArea->objectAttributes, TPMA_OBJECT, restricted))
71 return TPM_RCS_ATTRIBUTES + RC_HMAC_handle;
72
73 // and that it is a signing key
74 if(!IS_ATTRIBUTE(publicArea->objectAttributes, TPMA_OBJECT, sign))
75 return TPM_RCS_KEY + RC_HMAC_handle;
76
77 // See if the key has a default
78 if(publicArea->parameters.keyedHashDetail.scheme.scheme == TPM_ALG_NULL)
79 // it doesn't so use the input value
80 hashAlg = in->hashAlg;
81 else
82 {
83 // key has a default so use it
84 hashAlg
85 = publicArea->parameters.keyedHashDetail.scheme.details.hmac.hashAlg;
86 // and verify that the input was either the TPM_ALG_NULL or the default
87 if(in->hashAlg != TPM_ALG_NULL && in->hashAlg != hashAlg)
88 hashAlg = TPM_ALG_NULL;
89 }
90 // if we ended up without a hash algorithm then return an error
91 if(hashAlg == TPM_ALG_NULL)
92 return TPM_RCS_VALUE + RC_HMAC_hashAlg;
93
94 // Command Output
95
96 // Start HMAC stack
97 out->outHMAC.t.size = CryptHmacStart2B(&hmacState, hashAlg,
98 &hmacObject->sensitive.sensitive.bits.b);
99 // Adding HMAC data
100 CryptDigestUpdate2B(&hmacState.hashState, &in->buffer.b);
101
102 // Complete HMAC
103 CryptHmacEnd2B(&hmacState, &out->outHMAC.b);
104
105 return TPM_RC_SUCCESS;
106 }
107
108 #endif // CC_HMAC