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 "EC_Ephemeral_fp.h"
37
38 #if CC_EC_Ephemeral // Conditional expansion of this file
39
40 /*(See part 3 specification)
41 // This command creates an ephemeral key using the commit mechanism
42 */
43 // Return Type: TPM_RC
44 // TPM_RC_NO_RESULT the TPM is not able to generate an 'r' value
45 TPM_RC
TPM2_EC_Ephemeral(EC_Ephemeral_In * in,EC_Ephemeral_Out * out)46 TPM2_EC_Ephemeral(
47 EC_Ephemeral_In *in, // IN: input parameter list
48 EC_Ephemeral_Out *out // OUT: output parameter list
49 )
50 {
51 TPM2B_ECC_PARAMETER r;
52 TPM_RC result;
53 //
54 do
55 {
56 // Get the random value that will be used in the point multiplications
57 // Note: this does not commit the count.
58 if(!CryptGenerateR(&r, NULL, in->curveID, NULL))
59 return TPM_RC_NO_RESULT;
60 // do a point multiply
61 result = CryptEccPointMultiply(&out->Q.point, in->curveID, NULL, &r,
62 NULL, NULL);
63 // commit the count value if either the r value results in the point at
64 // infinity or if the value is good. The commit on the r value for infinity
65 // is so that the r value will be skipped.
66 if((result == TPM_RC_SUCCESS) || (result == TPM_RC_NO_RESULT))
67 out->counter = CryptCommit();
68 } while(result == TPM_RC_NO_RESULT);
69
70 return TPM_RC_SUCCESS;
71 }
72
73 #endif // CC_EC_Ephemeral