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
|
/*
* Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "inner.h"
/* see bearssl_block.h */
void
br_aes_small_ctrcbc_init(br_aes_small_ctrcbc_keys *ctx,
const void *key, size_t len)
{
ctx->vtable = &br_aes_small_ctrcbc_vtable;
ctx->num_rounds = br_aes_keysched(ctx->skey, key, len);
}
static void
xorbuf(void *dst, const void *src, size_t len)
{
unsigned char *d;
const unsigned char *s;
d = dst;
s = src;
while (len -- > 0) {
*d ++ ^= *s ++;
}
}
/* see bearssl_block.h */
void
br_aes_small_ctrcbc_ctr(const br_aes_small_ctrcbc_keys *ctx,
void *ctr, void *data, size_t len)
{
unsigned char *buf, *bctr;
uint32_t cc0, cc1, cc2, cc3;
buf = data;
bctr = ctr;
cc3 = br_dec32be(bctr + 0);
cc2 = br_dec32be(bctr + 4);
cc1 = br_dec32be(bctr + 8);
cc0 = br_dec32be(bctr + 12);
while (len > 0) {
unsigned char tmp[16];
uint32_t carry;
br_enc32be(tmp + 0, cc3);
br_enc32be(tmp + 4, cc2);
br_enc32be(tmp + 8, cc1);
br_enc32be(tmp + 12, cc0);
br_aes_small_encrypt(ctx->num_rounds, ctx->skey, tmp);
xorbuf(buf, tmp, 16);
buf += 16;
len -= 16;
cc0 ++;
carry = (~(cc0 | -cc0)) >> 31;
cc1 += carry;
carry &= (~(cc1 | -cc1)) >> 31;
cc2 += carry;
carry &= (~(cc2 | -cc2)) >> 31;
cc3 += carry;
}
br_enc32be(bctr + 0, cc3);
br_enc32be(bctr + 4, cc2);
br_enc32be(bctr + 8, cc1);
br_enc32be(bctr + 12, cc0);
}
/* see bearssl_block.h */
void
br_aes_small_ctrcbc_mac(const br_aes_small_ctrcbc_keys *ctx,
void *cbcmac, const void *data, size_t len)
{
const unsigned char *buf;
buf = data;
while (len > 0) {
xorbuf(cbcmac, buf, 16);
br_aes_small_encrypt(ctx->num_rounds, ctx->skey, cbcmac);
buf += 16;
len -= 16;
}
}
/* see bearssl_block.h */
void
br_aes_small_ctrcbc_encrypt(const br_aes_small_ctrcbc_keys *ctx,
void *ctr, void *cbcmac, void *data, size_t len)
{
br_aes_small_ctrcbc_ctr(ctx, ctr, data, len);
br_aes_small_ctrcbc_mac(ctx, cbcmac, data, len);
}
/* see bearssl_block.h */
void
br_aes_small_ctrcbc_decrypt(const br_aes_small_ctrcbc_keys *ctx,
void *ctr, void *cbcmac, void *data, size_t len)
{
br_aes_small_ctrcbc_mac(ctx, cbcmac, data, len);
br_aes_small_ctrcbc_ctr(ctx, ctr, data, len);
}
/* see bearssl_block.h */
const br_block_ctrcbc_class br_aes_small_ctrcbc_vtable = {
sizeof(br_aes_small_ctrcbc_keys),
16,
4,
(void (*)(const br_block_ctrcbc_class **, const void *, size_t))
&br_aes_small_ctrcbc_init,
(void (*)(const br_block_ctrcbc_class *const *,
void *, void *, void *, size_t))
&br_aes_small_ctrcbc_encrypt,
(void (*)(const br_block_ctrcbc_class *const *,
void *, void *, void *, size_t))
&br_aes_small_ctrcbc_decrypt,
(void (*)(const br_block_ctrcbc_class *const *,
void *, void *, size_t))
&br_aes_small_ctrcbc_ctr,
(void (*)(const br_block_ctrcbc_class *const *,
void *, const void *, size_t))
&br_aes_small_ctrcbc_mac
};
|
