1 /*############################################################################
2 # Copyright 2016-2017 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
17 /*!
18 * \file
19 * \brief Commitment hash implementation.
20 */
21 #include "epid/common/1.1/src/commitment.h"
22 #include <limits.h>
23 #include <stdio.h>
24 #include "epid/common/math/bignum.h"
25 #include "epid/common/math/src/bignum-internal.h"
26 #include "epid/common/src/endian_convert.h"
27 #include "epid/common/src/memory.h"
28
SetKeySpecificEpid11CommitValues(Epid11GroupPubKey const * pub_key,Epid11CommitValues * values)29 EpidStatus SetKeySpecificEpid11CommitValues(Epid11GroupPubKey const* pub_key,
30 Epid11CommitValues* values) {
31 static const Epid11Params params = {
32 #include "epid/common/1.1/src/epid11params_tate.inc"
33 };
34
35 if (!pub_key || !values) return kEpidBadArgErr;
36
37 values->p = params.p;
38 values->g1 = params.g1;
39 values->g2 = params.g2;
40 values->g3 = params.g3;
41 values->h1 = pub_key->h1;
42 values->h2 = pub_key->h2;
43 values->w = pub_key->w;
44
45 return kEpidNoErr;
46 }
47
SetCalculatedEpid11CommitValues(Epid11G3ElemStr const * B,Epid11G3ElemStr const * K,Epid11G1ElemStr const * T1,Epid11G1ElemStr const * T2,EcPoint const * R1,EcPoint const * R2,EcPoint const * R3,FfElement const * R4,EcGroup * G1,EcGroup * G3,FiniteField * GT,Epid11CommitValues * values)48 EpidStatus SetCalculatedEpid11CommitValues(
49 Epid11G3ElemStr const* B, Epid11G3ElemStr const* K,
50 Epid11G1ElemStr const* T1, Epid11G1ElemStr const* T2, EcPoint const* R1,
51 EcPoint const* R2, EcPoint const* R3, FfElement const* R4, EcGroup* G1,
52 EcGroup* G3, FiniteField* GT, Epid11CommitValues* values) {
53 EpidStatus result;
54 if (!B || !K || !T1 || !T2 || !R1 || !R2 || !R3 || !R4 || !G1 || !G3 || !GT ||
55 !values) {
56 return kEpidBadArgErr;
57 }
58
59 values->B = *B;
60 values->K = *K;
61 values->T1 = *T1;
62 values->T2 = *T2;
63
64 result = WriteEcPoint(G1, R1, &values->R1, sizeof(values->R1));
65 if (kEpidNoErr != result) return result;
66 result = WriteEcPoint(G1, R2, &values->R2, sizeof(values->R2));
67 if (kEpidNoErr != result) return result;
68 result = WriteEcPoint(G3, R3, &values->R3, sizeof(values->R3));
69 if (kEpidNoErr != result) return result;
70 result = WriteFfElement(GT, R4, &values->R4, sizeof(values->R4));
71 if (kEpidNoErr != result) return result;
72
73 return kEpidNoErr;
74 }
75
CalculateEpid11CommitmentHash(Epid11CommitValues const * values,void const * msg,uint32_t msg_len,OctStr80 const * nd,Sha256Digest * c)76 EpidStatus CalculateEpid11CommitmentHash(Epid11CommitValues const* values,
77 void const* msg, uint32_t msg_len,
78 OctStr80 const* nd, Sha256Digest* c) {
79 EpidStatus result;
80
81 #pragma pack(1)
82 struct {
83 Sha256Digest t4;
84 OctStr80 nd;
85 uint32_t msg_len;
86 uint8_t msg[1];
87 }* t4mconcat_buf = NULL;
88 #pragma pack()
89 size_t max_msg_len =
90 SIZE_MAX - (sizeof(*t4mconcat_buf) - sizeof(t4mconcat_buf->msg));
91 size_t t4mconcat_size =
92 sizeof(*t4mconcat_buf) - sizeof(t4mconcat_buf->msg) + msg_len;
93
94 if (!values || !nd || !c) return kEpidBadArgErr;
95 if (!msg && (0 != msg_len)) {
96 // if message is non-empty it must have both length and content
97 return kEpidBadArgErr;
98 }
99 if (max_msg_len < (size_t)msg_len) {
100 return kEpidBadArgErr;
101 }
102
103 do {
104 // compute c = H(t4 || nd || msg_len || msg).
105 t4mconcat_buf = SAFE_ALLOC(t4mconcat_size);
106 if (!t4mconcat_buf) {
107 result = kEpidMemAllocErr;
108 break;
109 }
110 // Calculate c = Hash(t4 || nd || mSize || m) where t4 is Hash(p || g1 || g2
111 // || g3 || h1 || h2 || w || B || K || T1 || T2 || R1 || R2 || R3 || R4).
112 result = Sha256MessageDigest(values, sizeof(*values), &t4mconcat_buf->t4);
113 if (kEpidNoErr != result) break;
114 t4mconcat_buf->nd = *nd;
115 t4mconcat_buf->msg_len = ntohl(msg_len);
116 // place variable length msg into t4mconcat_buf
117 if (msg) {
118 if (0 != memcpy_S(&t4mconcat_buf->msg[0],
119 t4mconcat_size - sizeof(*t4mconcat_buf) +
120 sizeof(t4mconcat_buf->msg),
121 msg, msg_len)) {
122 result = kEpidBadArgErr;
123 break;
124 }
125 }
126 result = Sha256MessageDigest(t4mconcat_buf, t4mconcat_size, c);
127 if (kEpidNoErr != result) break;
128
129 result = kEpidNoErr;
130 } while (0);
131
132 SAFE_FREE(t4mconcat_buf);
133
134 return result;
135 }
136