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
|
#include <machine/rtems-bsd-user-space.h>
/*
* One-key CBC MAC (OMAC1) hash with AES
*
* Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "aes.h"
#include "aes_wrap.h"
static void gf_mulx(u8 *pad)
{
int i, carry;
carry = pad[0] & 0x80;
for (i = 0; i < AES_BLOCK_SIZE - 1; i++)
pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
pad[AES_BLOCK_SIZE - 1] <<= 1;
if (carry)
pad[AES_BLOCK_SIZE - 1] ^= 0x87;
}
/**
* omac1_aes_vector - One-Key CBC MAC (OMAC1) hash with AES
* @key: Key for the hash operation
* @key_len: Key length in octets
* @num_elem: Number of elements in the data vector
* @addr: Pointers to the data areas
* @len: Lengths of the data blocks
* @mac: Buffer for MAC (128 bits, i.e., 16 bytes)
* Returns: 0 on success, -1 on failure
*
* This is a mode for using block cipher (AES in this case) for authentication.
* OMAC1 was standardized with the name CMAC by NIST in a Special Publication
* (SP) 800-38B.
*/
int omac1_aes_vector(const u8 *key, size_t key_len, size_t num_elem,
const u8 *addr[], const size_t *len, u8 *mac)
{
void *ctx;
u8 cbc[AES_BLOCK_SIZE], pad[AES_BLOCK_SIZE];
const u8 *pos, *end;
size_t i, e, left, total_len;
if (TEST_FAIL())
return -1;
ctx = aes_encrypt_init(key, key_len);
if (ctx == NULL)
return -1;
os_memset(cbc, 0, AES_BLOCK_SIZE);
total_len = 0;
for (e = 0; e < num_elem; e++)
total_len += len[e];
left = total_len;
e = 0;
pos = addr[0];
end = pos + len[0];
while (left >= AES_BLOCK_SIZE) {
for (i = 0; i < AES_BLOCK_SIZE; i++) {
cbc[i] ^= *pos++;
if (pos >= end) {
/*
* Stop if there are no more bytes to process
* since there are no more entries in the array.
*/
if (i + 1 == AES_BLOCK_SIZE &&
left == AES_BLOCK_SIZE)
break;
e++;
pos = addr[e];
end = pos + len[e];
}
}
if (left > AES_BLOCK_SIZE)
aes_encrypt(ctx, cbc, cbc);
left -= AES_BLOCK_SIZE;
}
os_memset(pad, 0, AES_BLOCK_SIZE);
aes_encrypt(ctx, pad, pad);
gf_mulx(pad);
if (left || total_len == 0) {
for (i = 0; i < left; i++) {
cbc[i] ^= *pos++;
if (pos >= end) {
/*
* Stop if there are no more bytes to process
* since there are no more entries in the array.
*/
if (i + 1 == left)
break;
e++;
pos = addr[e];
end = pos + len[e];
}
}
cbc[left] ^= 0x80;
gf_mulx(pad);
}
for (i = 0; i < AES_BLOCK_SIZE; i++)
pad[i] ^= cbc[i];
aes_encrypt(ctx, pad, mac);
aes_encrypt_deinit(ctx);
return 0;
}
/**
* omac1_aes_128_vector - One-Key CBC MAC (OMAC1) hash with AES-128
* @key: 128-bit key for the hash operation
* @num_elem: Number of elements in the data vector
* @addr: Pointers to the data areas
* @len: Lengths of the data blocks
* @mac: Buffer for MAC (128 bits, i.e., 16 bytes)
* Returns: 0 on success, -1 on failure
*
* This is a mode for using block cipher (AES in this case) for authentication.
* OMAC1 was standardized with the name CMAC by NIST in a Special Publication
* (SP) 800-38B.
*/
int omac1_aes_128_vector(const u8 *key, size_t num_elem,
const u8 *addr[], const size_t *len, u8 *mac)
{
return omac1_aes_vector(key, 16, num_elem, addr, len, mac);
}
/**
* omac1_aes_128 - One-Key CBC MAC (OMAC1) hash with AES-128 (aka AES-CMAC)
* @key: 128-bit key for the hash operation
* @data: Data buffer for which a MAC is determined
* @data_len: Length of data buffer in bytes
* @mac: Buffer for MAC (128 bits, i.e., 16 bytes)
* Returns: 0 on success, -1 on failure
*
* This is a mode for using block cipher (AES in this case) for authentication.
* OMAC1 was standardized with the name CMAC by NIST in a Special Publication
* (SP) 800-38B.
*/
int omac1_aes_128(const u8 *key, const u8 *data, size_t data_len, u8 *mac)
{
return omac1_aes_128_vector(key, 1, &data, &data_len, mac);
}
/**
* omac1_aes_256 - One-Key CBC MAC (OMAC1) hash with AES-256 (aka AES-CMAC)
* @key: 256-bit key for the hash operation
* @data: Data buffer for which a MAC is determined
* @data_len: Length of data buffer in bytes
* @mac: Buffer for MAC (128 bits, i.e., 16 bytes)
* Returns: 0 on success, -1 on failure
*
* This is a mode for using block cipher (AES in this case) for authentication.
* OMAC1 was standardized with the name CMAC by NIST in a Special Publication
* (SP) 800-38B.
*/
int omac1_aes_256(const u8 *key, const u8 *data, size_t data_len, u8 *mac)
{
return omac1_aes_vector(key, 32, 1, &data, &data_len, mac);
}
|
