1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
#include "crypto/s2n_rsa_signing.h"
#include <openssl/evp.h>
#include <openssl/rsa.h>
#include "crypto/s2n_hash.h"
#include "crypto/s2n_pkey.h"
#include "crypto/s2n_rsa_pss.h"
#include "error/s2n_errno.h"
#include "stuffer/s2n_stuffer.h"
#include "utils/s2n_blob.h"
#include "utils/s2n_safety.h"
static int s2n_hash_alg_to_NID[] = {
[S2N_HASH_MD5_SHA1] = NID_md5_sha1,
[S2N_HASH_SHA1] = NID_sha1,
[S2N_HASH_SHA224] = NID_sha224,
[S2N_HASH_SHA256] = NID_sha256,
[S2N_HASH_SHA384] = NID_sha384,
[S2N_HASH_SHA512] = NID_sha512
};
int s2n_hash_NID_type(s2n_hash_algorithm alg, int *out)
{
switch (alg) {
case S2N_HASH_MD5_SHA1:
case S2N_HASH_SHA1:
case S2N_HASH_SHA224:
case S2N_HASH_SHA256:
case S2N_HASH_SHA384:
case S2N_HASH_SHA512:
*out = s2n_hash_alg_to_NID[alg];
break;
default:
POSIX_BAIL(S2N_ERR_HASH_INVALID_ALGORITHM);
}
return 0;
}
int s2n_rsa_pkcs1v15_sign_digest(const struct s2n_pkey *priv, s2n_hash_algorithm hash_alg,
struct s2n_blob *digest, struct s2n_blob *signature)
{
POSIX_ENSURE_REF(priv);
POSIX_ENSURE_REF(digest);
POSIX_ENSURE_REF(signature);
int NID_type = 0;
POSIX_GUARD(s2n_hash_NID_type(hash_alg, &NID_type));
const s2n_rsa_private_key *rsa_key = &priv->key.rsa_key;
unsigned int signature_size = signature->size;
/* Safety: RSA_sign does not mutate the key */
POSIX_GUARD_OSSL(RSA_sign(NID_type, digest->data, digest->size, signature->data, &signature_size,
s2n_unsafe_rsa_get_non_const(rsa_key)),
S2N_ERR_SIGN);
POSIX_ENSURE(signature_size <= signature->size, S2N_ERR_SIZE_MISMATCH);
signature->size = signature_size;
return S2N_SUCCESS;
}
int s2n_rsa_pkcs1v15_sign(const struct s2n_pkey *priv, struct s2n_hash_state *digest, struct s2n_blob *signature)
{
POSIX_ENSURE_REF(digest);
uint8_t digest_length = 0;
POSIX_GUARD(s2n_hash_digest_size(digest->alg, &digest_length));
POSIX_ENSURE_LTE(digest_length, S2N_MAX_DIGEST_LEN);
uint8_t digest_out[S2N_MAX_DIGEST_LEN] = { 0 };
POSIX_GUARD(s2n_hash_digest(digest, digest_out, digest_length));
struct s2n_blob digest_blob = { 0 };
POSIX_GUARD(s2n_blob_init(&digest_blob, digest_out, digest_length));
POSIX_GUARD(s2n_rsa_pkcs1v15_sign_digest(priv, digest->alg, &digest_blob, signature));
return S2N_SUCCESS;
}
int s2n_rsa_pkcs1v15_verify(const struct s2n_pkey *pub, struct s2n_hash_state *digest, struct s2n_blob *signature)
{
uint8_t digest_length;
int digest_NID_type;
POSIX_GUARD(s2n_hash_digest_size(digest->alg, &digest_length));
POSIX_GUARD(s2n_hash_NID_type(digest->alg, &digest_NID_type));
POSIX_ENSURE_LTE(digest_length, S2N_MAX_DIGEST_LEN);
const s2n_rsa_public_key *rsa_key = &pub->key.rsa_key;
uint8_t digest_out[S2N_MAX_DIGEST_LEN];
POSIX_GUARD(s2n_hash_digest(digest, digest_out, digest_length));
/* Safety: RSA_verify does not mutate the key */
POSIX_GUARD_OSSL(RSA_verify(digest_NID_type, digest_out, digest_length, signature->data, signature->size,
s2n_unsafe_rsa_get_non_const(rsa_key)),
S2N_ERR_VERIFY_SIGNATURE);
return 0;
}
/* this function returns whether RSA PSS signing is supported */
int s2n_is_rsa_pss_signing_supported()
{
return RSA_PSS_SIGNING_SUPPORTED;
}
#if RSA_PSS_SIGNING_SUPPORTED
static int s2n_evp_pkey_ctx_set_rsa_signature_digest(EVP_PKEY_CTX *ctx, const EVP_MD *digest_alg)
{
POSIX_GUARD_OSSL(S2N_EVP_PKEY_CTX_set_signature_md(ctx, digest_alg), S2N_ERR_INVALID_SIGNATURE_ALGORITHM);
POSIX_GUARD_OSSL(EVP_PKEY_CTX_set_rsa_mgf1_md(ctx, (EVP_MD *) (uintptr_t) digest_alg), S2N_ERR_INVALID_SIGNATURE_ALGORITHM);
return 0;
}
static void s2n_evp_pkey_ctx_free(EVP_PKEY_CTX **ctx)
{
EVP_PKEY_CTX_free(*ctx);
}
int s2n_rsa_pss_sign_digest(const struct s2n_pkey *priv, s2n_hash_algorithm hash_alg,
struct s2n_blob *digest_in, struct s2n_blob *signature_out)
{
POSIX_ENSURE_REF(priv);
POSIX_ENSURE_REF(digest_in);
POSIX_ENSURE_REF(signature_out);
const EVP_MD *digest_alg = s2n_hash_alg_to_evp_md(hash_alg);
POSIX_ENSURE_REF(digest_alg);
/* For more info see: https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_sign.html */
DEFER_CLEANUP(EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new(priv->pkey, NULL), s2n_evp_pkey_ctx_free);
POSIX_ENSURE_REF(ctx);
size_t signature_len = signature_out->size;
POSIX_GUARD_OSSL(EVP_PKEY_sign_init(ctx), S2N_ERR_SIGN);
POSIX_GUARD_OSSL(EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PSS_PADDING), S2N_ERR_SIGN);
POSIX_GUARD(s2n_evp_pkey_ctx_set_rsa_signature_digest(ctx, digest_alg));
POSIX_GUARD_OSSL(EVP_PKEY_CTX_set_rsa_pss_saltlen(ctx, RSA_PSS_SALTLEN_DIGEST), S2N_ERR_SIGN);
/* Calling EVP_PKEY_sign() with NULL will only update the signature_len parameter so users can validate sizes. */
POSIX_GUARD_OSSL(EVP_PKEY_sign(ctx, NULL, &signature_len, digest_in->data, digest_in->size), S2N_ERR_SIGN);
POSIX_ENSURE(signature_len <= signature_out->size, S2N_ERR_SIZE_MISMATCH);
/* Actually sign the digest */
POSIX_GUARD_OSSL(EVP_PKEY_sign(ctx, signature_out->data, &signature_len, digest_in->data, digest_in->size), S2N_ERR_SIGN);
signature_out->size = signature_len;
return S2N_SUCCESS;
}
int s2n_rsa_pss_sign(const struct s2n_pkey *priv, struct s2n_hash_state *digest, struct s2n_blob *signature_out)
{
POSIX_ENSURE_REF(digest);
uint8_t digest_length = 0;
uint8_t digest_data[S2N_MAX_DIGEST_LEN] = { 0 };
POSIX_GUARD(s2n_hash_digest_size(digest->alg, &digest_length));
POSIX_GUARD(s2n_hash_digest(digest, digest_data, digest_length));
struct s2n_blob digest_blob = { 0 };
POSIX_GUARD(s2n_blob_init(&digest_blob, digest_data, digest_length));
POSIX_GUARD(s2n_rsa_pss_sign_digest(priv, digest->alg, &digest_blob, signature_out));
return S2N_SUCCESS;
}
int s2n_rsa_pss_verify(const struct s2n_pkey *pub, struct s2n_hash_state *digest, struct s2n_blob *signature_in)
{
POSIX_ENSURE_REF(pub);
uint8_t digest_length;
uint8_t digest_data[S2N_MAX_DIGEST_LEN];
POSIX_GUARD(s2n_hash_digest_size(digest->alg, &digest_length));
POSIX_GUARD(s2n_hash_digest(digest, digest_data, digest_length));
const EVP_MD *digest_alg = s2n_hash_alg_to_evp_md(digest->alg);
POSIX_ENSURE_REF(digest_alg);
/* For more info see: https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_verify.html */
DEFER_CLEANUP(EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new(pub->pkey, NULL), s2n_evp_pkey_ctx_free);
POSIX_ENSURE_REF(ctx);
POSIX_GUARD_OSSL(EVP_PKEY_verify_init(ctx), S2N_ERR_VERIFY_SIGNATURE);
POSIX_GUARD_OSSL(EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PSS_PADDING), S2N_ERR_VERIFY_SIGNATURE);
POSIX_GUARD(s2n_evp_pkey_ctx_set_rsa_signature_digest(ctx, digest_alg));
POSIX_GUARD_OSSL(EVP_PKEY_CTX_set_rsa_pss_saltlen(ctx, RSA_PSS_SALTLEN_DIGEST), S2N_ERR_VERIFY_SIGNATURE);
POSIX_GUARD_OSSL(EVP_PKEY_verify(ctx, signature_in->data, signature_in->size,
digest_data, digest_length),
S2N_ERR_VERIFY_SIGNATURE);
return S2N_SUCCESS;
}
#else
int s2n_rsa_pss_sign_digest(const struct s2n_pkey *priv, s2n_hash_algorithm hash_alg,
struct s2n_blob *digest_in, struct s2n_blob *signature_out)
{
POSIX_BAIL(S2N_ERR_RSA_PSS_NOT_SUPPORTED);
}
int s2n_rsa_pss_sign(const struct s2n_pkey *priv, struct s2n_hash_state *digest, struct s2n_blob *signature_out)
{
POSIX_BAIL(S2N_ERR_RSA_PSS_NOT_SUPPORTED);
}
int s2n_rsa_pss_verify(const struct s2n_pkey *pub, struct s2n_hash_state *digest, struct s2n_blob *signature_in)
{
POSIX_BAIL(S2N_ERR_RSA_PSS_NOT_SUPPORTED);
}
#endif
|
