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
|
/*
* 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 <openssl/aes.h>
#include "error/s2n_errno.h"
#include "crypto/s2n_cipher.h"
#include "crypto/s2n_openssl.h"
#include "utils/s2n_safety.h"
#include "utils/s2n_blob.h"
static uint8_t s2n_cbc_cipher_aes128_available()
{
return (EVP_aes_128_cbc() ? 1 : 0);
}
static uint8_t s2n_cbc_cipher_aes256_available()
{
return (EVP_aes_256_cbc() ? 1 : 0);
}
static int s2n_cbc_cipher_aes_encrypt(struct s2n_session_key *key, struct s2n_blob *iv, struct s2n_blob *in, struct s2n_blob *out)
{
POSIX_ENSURE_GTE(out->size, in->size);
POSIX_GUARD_OSSL(EVP_EncryptInit_ex(key->evp_cipher_ctx, NULL, NULL, NULL, iv->data), S2N_ERR_KEY_INIT);
/* len is set by EVP_EncryptUpdate and checked post operation */
int len = 0;
POSIX_GUARD_OSSL(EVP_EncryptUpdate(key->evp_cipher_ctx, out->data, &len, in->data, in->size), S2N_ERR_ENCRYPT);
S2N_ERROR_IF(len != in->size, S2N_ERR_ENCRYPT);
return 0;
}
int s2n_cbc_cipher_aes_decrypt(struct s2n_session_key *key, struct s2n_blob *iv, struct s2n_blob *in, struct s2n_blob *out)
{
POSIX_ENSURE_GTE(out->size, in->size);
POSIX_GUARD_OSSL(EVP_DecryptInit_ex(key->evp_cipher_ctx, NULL, NULL, NULL, iv->data), S2N_ERR_KEY_INIT);
/* len is set by EVP_DecryptUpdate. It is not checked here but padding is manually removed and therefore
* the decryption operation is validated. */
int len = 0;
POSIX_GUARD_OSSL(EVP_DecryptUpdate(key->evp_cipher_ctx, out->data, &len, in->data, in->size), S2N_ERR_DECRYPT);
return 0;
}
int s2n_cbc_cipher_aes128_set_decryption_key(struct s2n_session_key *key, struct s2n_blob *in)
{
POSIX_ENSURE_EQ(in->size, 128 / 8);
/* Always returns 1 */
EVP_CIPHER_CTX_set_padding(key->evp_cipher_ctx, 0);
POSIX_GUARD_OSSL(EVP_DecryptInit_ex(key->evp_cipher_ctx, EVP_aes_128_cbc(), NULL, in->data, NULL), S2N_ERR_KEY_INIT);
return 0;
}
static int s2n_cbc_cipher_aes128_set_encryption_key(struct s2n_session_key *key, struct s2n_blob *in)
{
POSIX_ENSURE_EQ(in->size, 128 / 8);
EVP_CIPHER_CTX_set_padding(key->evp_cipher_ctx, 0);
POSIX_GUARD_OSSL(EVP_EncryptInit_ex(key->evp_cipher_ctx, EVP_aes_128_cbc(), NULL, in->data, NULL), S2N_ERR_KEY_INIT);
return 0;
}
static int s2n_cbc_cipher_aes256_set_decryption_key(struct s2n_session_key *key, struct s2n_blob *in)
{
POSIX_ENSURE_EQ(in->size, 256 / 8);
EVP_CIPHER_CTX_set_padding(key->evp_cipher_ctx, 0);
POSIX_GUARD_OSSL(EVP_DecryptInit_ex(key->evp_cipher_ctx, EVP_aes_256_cbc(), NULL, in->data, NULL), S2N_ERR_KEY_INIT);
return 0;
}
int s2n_cbc_cipher_aes256_set_encryption_key(struct s2n_session_key *key, struct s2n_blob *in)
{
POSIX_ENSURE_EQ(in->size, 256 / 8);
EVP_CIPHER_CTX_set_padding(key->evp_cipher_ctx, 0);
POSIX_GUARD_OSSL(EVP_EncryptInit_ex(key->evp_cipher_ctx, EVP_aes_256_cbc(), NULL, in->data, NULL), S2N_ERR_KEY_INIT);
return 0;
}
static int s2n_cbc_cipher_aes_init(struct s2n_session_key *key)
{
s2n_evp_ctx_init(key->evp_cipher_ctx);
return 0;
}
static int s2n_cbc_cipher_aes_destroy_key(struct s2n_session_key *key)
{
EVP_CIPHER_CTX_cleanup(key->evp_cipher_ctx);
return 0;
}
struct s2n_cipher s2n_aes128 = {
.key_material_size = 16,
.type = S2N_CBC,
.io.cbc = {
.block_size = 16,
.record_iv_size = 16,
.decrypt = s2n_cbc_cipher_aes_decrypt,
.encrypt = s2n_cbc_cipher_aes_encrypt},
.is_available = s2n_cbc_cipher_aes128_available,
.init = s2n_cbc_cipher_aes_init,
.set_decryption_key = s2n_cbc_cipher_aes128_set_decryption_key,
.set_encryption_key = s2n_cbc_cipher_aes128_set_encryption_key,
.destroy_key = s2n_cbc_cipher_aes_destroy_key,
};
struct s2n_cipher s2n_aes256 = {
.key_material_size = 32,
.type = S2N_CBC,
.io.cbc = {
.block_size = 16,
.record_iv_size = 16,
.decrypt = s2n_cbc_cipher_aes_decrypt,
.encrypt = s2n_cbc_cipher_aes_encrypt},
.is_available = s2n_cbc_cipher_aes256_available,
.init = s2n_cbc_cipher_aes_init,
.set_decryption_key = s2n_cbc_cipher_aes256_set_decryption_key,
.set_encryption_key = s2n_cbc_cipher_aes256_set_encryption_key,
.destroy_key = s2n_cbc_cipher_aes_destroy_key,
};
|
