1 /*
2 * Copyright (c) 2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #ifdef HKS_CONFIG_FILE
17 #include HKS_CONFIG_FILE
18 #else
19 #include "hks_config.h"
20 #endif
21
22 #ifdef HKS_SUPPORT_BN_C
23
24 #include "hks_openssl_bn.h"
25
26 #include <openssl/bn.h>
27 #include <stddef.h>
28
29 #include "hks_log.h"
30 #include "hks_mem.h"
31 #include "hks_openssl_engine.h"
32 #include "hks_template.h"
33 #include "securec.h"
34
BnFreeParams(struct HksBnExpModParams * bnParams)35 static void BnFreeParams(struct HksBnExpModParams *bnParams)
36 {
37 BN_free(bnParams->bnX);
38 BN_free(bnParams->bnA);
39 BN_free(bnParams->bnE);
40 BN_free(bnParams->bnN);
41 BN_CTX_free(bnParams->ctx);
42
43 bnParams->bnX = NULL;
44 bnParams->bnA = NULL;
45 bnParams->bnE = NULL;
46 bnParams->bnN = NULL;
47 bnParams->ctx = NULL;
48 }
49
BnBuildParams(struct HksBnExpModParams * bnParams,const struct HksBlob * a,const struct HksBlob * e,const struct HksBlob * n)50 static int32_t BnBuildParams(
51 struct HksBnExpModParams *bnParams, const struct HksBlob *a, const struct HksBlob *e, const struct HksBlob *n)
52 {
53 bnParams->ctx = BN_CTX_new();
54 bnParams->bnX = BN_new();
55 bnParams->bnA = BN_bin2bn(a->data, a->size, NULL);
56 bnParams->bnE = BN_bin2bn(e->data, e->size, NULL);
57 bnParams->bnN = BN_bin2bn(n->data, n->size, NULL);
58 if ((bnParams->ctx == NULL) || (bnParams->bnX == NULL) || (bnParams->bnA == NULL) || (bnParams->bnE == NULL) ||
59 (bnParams->bnN == NULL)) {
60 BnFreeParams(bnParams);
61 return HKS_ERROR_CRYPTO_ENGINE_ERROR;
62 }
63 return HKS_SUCCESS;
64 }
65
BnExpModExport(BIGNUM * bnX,struct HksBlob * x)66 static int32_t BnExpModExport(BIGNUM *bnX, struct HksBlob *x)
67 {
68 int32_t outLen = BN_num_bytes(bnX);
69 if ((outLen < 0) || (x->size < (uint32_t)outLen) || x->size > INT32_MAX) {
70 return HKS_ERROR_BUFFER_TOO_SMALL;
71 }
72
73 if (memset_s(x->data, x->size, 0, x->size) != EOK) {
74 HKS_LOG_E("memset x data failed!");
75 return HKS_ERROR_INSUFFICIENT_MEMORY;
76 }
77 if (outLen == 0) {
78 return HKS_SUCCESS;
79 }
80
81 uint8_t *bnOutput = (uint8_t *)HksMalloc(outLen);
82 HKS_IF_NULL_LOGE_RETURN(bnOutput, HKS_ERROR_MALLOC_FAIL, "malloc fail")
83
84 int32_t ret = HKS_SUCCESS;
85 do {
86 int32_t realOutLen = BN_bn2bin(bnX, bnOutput);
87 if (realOutLen != outLen) {
88 HKS_LOG_E("BN_bn2bin fail");
89 ret = HKS_ERROR_CRYPTO_ENGINE_ERROR;
90 break;
91 }
92
93 int32_t i = (int32_t)(x->size - 1);
94 int32_t j = realOutLen - 1; /* realOutLen is greater than 0; x->size is no less than realOutLen */
95 for (; j >= 0; --i, --j) { /* i is no less than j */
96 x->data[i] = bnOutput[j];
97 }
98 } while (0);
99
100 HKS_FREE(bnOutput);
101 return ret;
102 }
103
HksOpensslBnExpMod(struct HksBlob * x,const struct HksBlob * a,const struct HksBlob * e,const struct HksBlob * n)104 int32_t HksOpensslBnExpMod(struct HksBlob *x, const struct HksBlob *a,
105 const struct HksBlob *e, const struct HksBlob *n)
106 {
107 struct HksBnExpModParams bnParams;
108 (void)memset_s(&bnParams, sizeof(bnParams), 0, sizeof(bnParams));
109 int32_t ret = BnBuildParams(&bnParams, a, e, n);
110 HKS_IF_NOT_SUCC_LOGE_RETURN(ret, ret, "BnInitParams fail")
111
112 do {
113 /* mod 0 is not supported */
114 if (BN_is_zero(bnParams.bnN)) {
115 HKS_LOG_E("not support mod 0 operation.");
116 ret = HKS_ERROR_INVALID_ARGUMENT;
117 break;
118 }
119
120 ret = BN_mod_exp(bnParams.bnX, bnParams.bnA, bnParams.bnE, bnParams.bnN, bnParams.ctx);
121 if (ret != HKS_OPENSSL_SUCCESS) {
122 HKS_LOG_E("BN_mod_exp fail, ret = %" LOG_PUBLIC "d", ret);
123 ret = HKS_ERROR_CRYPTO_ENGINE_ERROR;
124 break;
125 }
126
127 ret = BnExpModExport(bnParams.bnX, x);
128 HKS_IF_NOT_SUCC_LOGE_BREAK(ret, "BnExpModExport fail")
129 } while (0);
130
131 BnFreeParams(&bnParams);
132 return ret;
133 }
134 #endif /* HKS_SUPPORT_BN_C */
135