1 /*
2 * Copyright (c) 2020-2022 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_mbedtls_bn.h"
25
26 #include <mbedtls/bignum.h>
27
28 #include "hks_log.h"
29 #include "hks_mbedtls_common.h"
30 #include "hks_template.h"
31
CheckBnExpModNx(const struct HksBlob * n,const struct HksBlob * x)32 static int32_t CheckBnExpModNx(const struct HksBlob *n, const struct HksBlob *x)
33 {
34 /* zero is even number, so doesn't have to be checked */
35 if ((n->data[n->size - 1] & 0x1) == 0x0) {
36 HKS_LOG_E("The param n(modular) must be odd!");
37 return HKS_ERROR_INVALID_ARGUMENT;
38 }
39
40 if (x->size < n->size) {
41 HKS_LOG_E("The param x's size is too samll! x size = 0x%" LOG_PUBLIC "X", x->size);
42 return HKS_ERROR_BUFFER_TOO_SMALL;
43 }
44
45 return HKS_SUCCESS;
46 }
47
HksMbedtlsBnExpMod(struct HksBlob * x,const struct HksBlob * a,const struct HksBlob * e,const struct HksBlob * n)48 int32_t HksMbedtlsBnExpMod(struct HksBlob *x, const struct HksBlob *a,
49 const struct HksBlob *e, const struct HksBlob *n)
50 {
51 int32_t ret = CheckBnExpModNx(n, x);
52 HKS_IF_NOT_SUCC_RETURN(ret, ret)
53
54 mbedtls_mpi bnX;
55 mbedtls_mpi bnA;
56 mbedtls_mpi bnE;
57 mbedtls_mpi bnN;
58
59 mbedtls_mpi_init(&bnX);
60 mbedtls_mpi_init(&bnA);
61 mbedtls_mpi_init(&bnE);
62 mbedtls_mpi_init(&bnN);
63
64 do {
65 ret = mbedtls_mpi_read_binary(&bnA, a->data, a->size);
66 if (ret != HKS_MBEDTLS_SUCCESS) {
67 HKS_LOG_E("Mbedtls mpi read a failed! mbedtls ret = 0x%" LOG_PUBLIC "X", ret);
68 break;
69 }
70 ret = mbedtls_mpi_read_binary(&bnE, e->data, e->size);
71 if (ret != HKS_MBEDTLS_SUCCESS) {
72 HKS_LOG_E("Mbedtls mpi read e failed! mbedtls ret = 0x%" LOG_PUBLIC "X", ret);
73 break;
74 }
75 ret = mbedtls_mpi_read_binary(&bnN, n->data, n->size);
76 if (ret != HKS_MBEDTLS_SUCCESS) {
77 HKS_LOG_E("Mbedtls mpi read n failed! mbedtls ret = 0x%" LOG_PUBLIC "X", ret);
78 break;
79 }
80
81 ret = mbedtls_mpi_exp_mod(&bnX, &bnA, &bnE, &bnN, NULL);
82 if (ret != HKS_MBEDTLS_SUCCESS) {
83 HKS_LOG_E("Mbedtls exp mod failed! mbedtls ret = 0x%" LOG_PUBLIC "X", ret);
84 break;
85 }
86
87 ret = mbedtls_mpi_write_binary(&bnX, x->data, x->size);
88 if (ret != HKS_MBEDTLS_SUCCESS) {
89 HKS_LOG_E("Mbedtls mpi write x failed! mbedtls ret = 0x%" LOG_PUBLIC "X", ret);
90 }
91 } while (0);
92
93 mbedtls_mpi_free(&bnX);
94 mbedtls_mpi_free(&bnA);
95 mbedtls_mpi_free(&bnE);
96 mbedtls_mpi_free(&bnN);
97 return ret;
98 }
99 #endif /* HKS_SUPPORT_BN_C */
100