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 "ECDH_ZGen_fp.h"
37
38 #if CC_ECDH_ZGen // Conditional expansion of this file
39
40 /*(See part 3 specification)
41 // This command uses the TPM to recover the Z value from a public point
42 */
43 // Return Type: TPM_RC
44 // TPM_RC_ATTRIBUTES key referenced by 'keyA' is restricted or
45 // not a decrypt key
46 // TPM_RC_KEY key referenced by 'keyA' is not an ECC key
47 // TPM_RC_NO_RESULT multiplying 'inPoint' resulted in a
48 // point at infinity
49 // TPM_RC_SCHEME the scheme of the key referenced by 'keyA'
50 // is not TPM_ALG_NULL, TPM_ALG_ECDH,
51 TPM_RC
TPM2_ECDH_ZGen(ECDH_ZGen_In * in,ECDH_ZGen_Out * out)52 TPM2_ECDH_ZGen(
53 ECDH_ZGen_In *in, // IN: input parameter list
54 ECDH_ZGen_Out *out // OUT: output parameter list
55 )
56 {
57 TPM_RC result;
58 OBJECT *eccKey;
59
60 // Input Validation
61 eccKey = HandleToObject(in->keyHandle);
62
63 // Selected key must be a non-restricted, decrypt ECC key
64 if(eccKey->publicArea.type != TPM_ALG_ECC)
65 return TPM_RCS_KEY + RC_ECDH_ZGen_keyHandle;
66 // Selected key needs to be unrestricted with the 'decrypt' attribute
67 if(IS_ATTRIBUTE(eccKey->publicArea.objectAttributes, TPMA_OBJECT, restricted)
68 || !IS_ATTRIBUTE(eccKey->publicArea.objectAttributes, TPMA_OBJECT, decrypt))
69 return TPM_RCS_ATTRIBUTES + RC_ECDH_ZGen_keyHandle;
70 // Make sure the scheme allows this use
71 if(eccKey->publicArea.parameters.eccDetail.scheme.scheme != TPM_ALG_ECDH
72 && eccKey->publicArea.parameters.eccDetail.scheme.scheme != TPM_ALG_NULL)
73 return TPM_RCS_SCHEME + RC_ECDH_ZGen_keyHandle;
74 // Command Output
75 // Compute Z. TPM_RC_ECC_POINT or TPM_RC_NO_RESULT may be returned here.
76 result = CryptEccPointMultiply(&out->outPoint.point,
77 eccKey->publicArea.parameters.eccDetail.curveID,
78 &in->inPoint.point,
79 &eccKey->sensitive.sensitive.ecc,
80 NULL, NULL);
81 if(result != TPM_RC_SUCCESS)
82 return RcSafeAddToResult(result, RC_ECDH_ZGen_inPoint);
83 return result;
84 }
85
86 #endif // CC_ECDH_ZGen