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 /// Tpm2Commit implementation.
17 /*! \file */
18
19 #include "epid/member/tpm2/commit.h"
20 #include <tss2/TPM_Types.h>
21 #include <tss2/tss.h>
22 #include "epid/common/math/ecgroup.h"
23 #include "epid/common/src/epid2params.h"
24 #include "epid/common/src/memory.h"
25 #include "epid/member/tpm2/ibm_tss/conversion.h"
26 #include "epid/member/tpm2/ibm_tss/printtss.h"
27 #include "epid/member/tpm2/ibm_tss/state.h"
28
29 /// Handle Intel(R) EPID Error with Break
30 #define BREAK_ON_EPID_ERROR(ret) \
31 if (kEpidNoErr != (ret)) { \
32 break; \
33 }
34
35 /// Bit 7 binary mask
36 #define BIT7 0x080
37 /// Binary 00011111
38 #define BITS0500 0x3f
39
Tpm2Commit(Tpm2Ctx * ctx,EcPoint const * p1,void const * s2,size_t s2_len,FfElement const * y2,EcPoint * k,EcPoint * l,EcPoint * e,uint16_t * counter)40 EpidStatus Tpm2Commit(Tpm2Ctx* ctx, EcPoint const* p1, void const* s2,
41 size_t s2_len, FfElement const* y2, EcPoint* k,
42 EcPoint* l, EcPoint* e, uint16_t* counter) {
43 EpidStatus sts = kEpidErr;
44 TPM_RC rc = TPM_RC_SUCCESS;
45
46 if (!ctx || !ctx->epid2_params || !ctx->key_handle) {
47 return kEpidBadArgErr;
48 }
49
50 if (s2 && s2_len <= 0) {
51 return kEpidBadArgErr;
52 }
53
54 if ((!s2 && y2) || (s2 && !y2)) {
55 return kEpidBadArgErr;
56 }
57
58 if (s2 && (!k || !l)) {
59 return kEpidBadArgErr;
60 }
61
62 if (!e || !counter) {
63 return kEpidBadArgErr;
64 }
65
66 if (s2_len > UINT16_MAX) {
67 return kEpidBadArgErr;
68 }
69
70 do {
71 FiniteField* Fq = ctx->epid2_params->Fq;
72 EcGroup* G1 = ctx->epid2_params->G1;
73 Commit_In in = {0};
74 Commit_Out out;
75 TPMI_SH_AUTH_SESSION sessionHandle0 = TPM_RS_PW;
76 unsigned int sessionAttributes0 = 0;
77
78 in.signHandle = ctx->key_handle;
79 if (p1) {
80 G1ElemStr p1_str = {0};
81 sts = WriteEcPoint(G1, p1, &p1_str, sizeof(p1_str));
82 BREAK_ON_EPID_ERROR(sts);
83 sts = ReadTpm2EcPoint(&p1_str, &in.P1);
84 BREAK_ON_EPID_ERROR(sts);
85 }
86 if (s2) {
87 FqElemStr y2_str = {0};
88 sts = WriteFfElement(Fq, y2, &y2_str, sizeof(y2_str));
89 BREAK_ON_EPID_ERROR(sts);
90 sts = ReadTpm2FfElement(&y2_str.data, &in.y2);
91 BREAK_ON_EPID_ERROR(sts);
92 in.s2.t.size = (UINT16)s2_len;
93 if (0 != memcpy_S(&in.s2.t.buffer, sizeof(in.s2.t.buffer), s2, s2_len)) {
94 sts = kEpidBadArgErr;
95 break;
96 }
97 }
98 rc = TSS_Execute(ctx->tss, (RESPONSE_PARAMETERS*)&out,
99 (COMMAND_PARAMETERS*)&in, NULL, TPM_CC_Commit,
100 sessionHandle0, NULL, sessionAttributes0, TPM_RH_NULL,
101 NULL, 0);
102 if (rc != TPM_RC_SUCCESS) {
103 print_tpm2_response_code("TPM2_Commit", rc);
104 // workaround based on Table 2:15 to filter response code format defining
105 // handle, session, or parameter number modifier if bit 7 is 1 error is
106 // RC_FMT1
107 if ((rc & BIT7) != 0) {
108 rc = rc & (BITS0500 | RC_FMT1);
109 if (TPM_RC_ATTRIBUTES == rc || TPM_RC_ECC_POINT == rc ||
110 TPM_RC_HASH == rc || TPM_RC_KEY == rc || TPM_RC_SCHEME == rc ||
111 TPM_RC_SIZE == rc)
112 sts = kEpidBadArgErr;
113 else
114 sts = kEpidErr;
115 } else {
116 if (TPM_RC_NO_RESULT == rc)
117 sts = kEpidBadArgErr;
118 else
119 sts = kEpidErr;
120 }
121 break;
122 }
123 if (out.E.size > 0) {
124 G1ElemStr e_str = {0};
125 sts = WriteTpm2EcPoint(&out.E, &e_str);
126 BREAK_ON_EPID_ERROR(sts);
127 sts = ReadEcPoint(G1, &e_str, sizeof(e_str), e);
128 BREAK_ON_EPID_ERROR(sts);
129 }
130 if (out.K.size > 0 && k) {
131 G1ElemStr k_str = {0};
132 sts = WriteTpm2EcPoint(&out.K, &k_str);
133 BREAK_ON_EPID_ERROR(sts);
134 sts = ReadEcPoint(G1, &k_str, sizeof(k_str), k);
135 BREAK_ON_EPID_ERROR(sts);
136 }
137 if (out.L.size > 0 && l) {
138 G1ElemStr l_str = {0};
139 sts = WriteTpm2EcPoint(&out.L, &l_str);
140 BREAK_ON_EPID_ERROR(sts);
141 sts = ReadEcPoint(G1, &l_str, sizeof(l_str), l);
142 BREAK_ON_EPID_ERROR(sts);
143 }
144 *counter = out.counter;
145 } while (0);
146 return sts;
147 }
148