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_KeyGen_fp.h"
37
38 #if CC_ECDH_KeyGen // Conditional expansion of this file
39
40 /*(See part 3 specification)
41 // This command uses the TPM to generate an ephemeral public key and the product
42 // of the ephemeral private key and the public portion of an ECC key.
43 */
44 // Return Type: TPM_RC
45 // TPM_RC_KEY 'keyHandle' does not reference an ECC key
46 TPM_RC
TPM2_ECDH_KeyGen(ECDH_KeyGen_In * in,ECDH_KeyGen_Out * out)47 TPM2_ECDH_KeyGen(
48 ECDH_KeyGen_In *in, // IN: input parameter list
49 ECDH_KeyGen_Out *out // OUT: output parameter list
50 )
51 {
52 OBJECT *eccKey;
53 TPM2B_ECC_PARAMETER sensitive;
54 TPM_RC result;
55
56 // Input Validation
57
58 eccKey = HandleToObject(in->keyHandle);
59
60 // Referenced key must be an ECC key
61 if(eccKey->publicArea.type != TPM_ALG_ECC)
62 return TPM_RCS_KEY + RC_ECDH_KeyGen_keyHandle;
63
64 // Command Output
65 do
66 {
67 TPMT_PUBLIC *keyPublic = &eccKey->publicArea;
68 // Create ephemeral ECC key
69 result = CryptEccNewKeyPair(&out->pubPoint.point, &sensitive,
70 keyPublic->parameters.eccDetail.curveID);
71 if(result == TPM_RC_SUCCESS)
72 {
73 // Compute Z
74 result = CryptEccPointMultiply(&out->zPoint.point,
75 keyPublic->parameters.eccDetail.curveID,
76 &keyPublic->unique.ecc,
77 &sensitive,
78 NULL, NULL);
79 // The point in the key is not on the curve. Indicate
80 // that the key is bad.
81 if(result == TPM_RC_ECC_POINT)
82 return TPM_RCS_KEY + RC_ECDH_KeyGen_keyHandle;
83 // The other possible error from CryptEccPointMultiply is
84 // TPM_RC_NO_RESULT indicating that the multiplication resulted in
85 // the point at infinity, so get a new random key and start over
86 // BTW, this never happens.
87 }
88 } while(result == TPM_RC_NO_RESULT);
89 return result;
90 }
91
92 #endif // CC_ECDH_KeyGen