1 /*############################################################################
2 # Copyright 2017 Intel Corporation
3 #
4 # Licensed under the Apache License, Version 2.0 (the "License");
5 # you may not use this file except in compliance with the License.
6 # You may obtain a copy of the License at
7 #
8 # http://www.apache.org/licenses/LICENSE-2.0
9 #
10 # Unless required by applicable law or agreed to in writing, software
11 # distributed under the License is distributed on an "AS IS" BASIS,
12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 # See the License for the specific language governing permissions and
14 # limitations under the License.
15 ############################################################################*/
16 /// Host join helper implementation
17 /*! \file */
18
19 #include "epid/member/src/join_commitment.h"
20
21 #include "epid/common/math/finitefield.h"
22 #include "epid/common/types.h"
23
24 /// Handle SDK Error with Break
25 #define BREAK_ON_EPID_ERROR(ret) \
26 if (kEpidNoErr != (ret)) { \
27 break; \
28 }
29
30 #pragma pack(1)
31 /// Storage for values to create commitment in Sign and Verify algorithms
32 typedef struct JoinPCommitValues {
33 BigNumStr p; ///< Intel(R) EPID 2.0 parameter p
34 G1ElemStr g1; ///< Intel(R) EPID 2.0 parameter g1
35 G2ElemStr g2; ///< Intel(R) EPID 2.0 parameter g2
36 G1ElemStr h1; ///< Group public key value h1
37 G1ElemStr h2; ///< Group public key value h2
38 G2ElemStr w; ///< Group public key value w
39 G1ElemStr F; ///< Variable F computed in algorithm
40 G1ElemStr R; ///< Variable R computed in algorithm
41 IssuerNonce NI; ///< Nonce
42 } JoinPCommitValues;
43 #pragma pack()
44
HashJoinCommitment(FiniteField * Fp,HashAlg hash_alg,GroupPubKey const * pub_key,G1ElemStr const * F_str,G1ElemStr const * R_str,IssuerNonce const * NI,FpElemStr * c_str)45 EpidStatus HashJoinCommitment(FiniteField* Fp, HashAlg hash_alg,
46 GroupPubKey const* pub_key,
47 G1ElemStr const* F_str, G1ElemStr const* R_str,
48 IssuerNonce const* NI, FpElemStr* c_str) {
49 EpidStatus sts = kEpidErr;
50 FfElement* c = NULL;
51
52 if (!Fp || !pub_key || !F_str || !R_str || !NI || !c_str) {
53 return kEpidBadArgErr;
54 }
55
56 do {
57 JoinPCommitValues commit_values = {0};
58 Epid2Params params = {
59 #include "epid/common/src/epid2params_ate.inc"
60 };
61
62 commit_values.p = params.p;
63 commit_values.g1 = params.g1;
64 commit_values.g2 = params.g2;
65 commit_values.h1 = pub_key->h1;
66 commit_values.h2 = pub_key->h2;
67 commit_values.w = pub_key->w;
68 commit_values.F = *F_str;
69 commit_values.R = *R_str;
70 commit_values.NI = *NI;
71
72 sts = NewFfElement(Fp, &c);
73 BREAK_ON_EPID_ERROR(sts);
74
75 // Step 4. The member computes c = Fp.hash(p || g1 || g2 || h1 ||
76 // h2 || w || F || R || NI).
77 sts = FfHash(Fp, &commit_values, sizeof(commit_values), hash_alg, c);
78 BREAK_ON_EPID_ERROR(sts);
79
80 sts = WriteFfElement(Fp, c, c_str, sizeof(*c_str));
81 BREAK_ON_EPID_ERROR(sts);
82
83 sts = kEpidNoErr;
84 } while (0);
85
86 DeleteFfElement(&c);
87
88 return sts;
89 }
90