/src/nettle-with-libgmp/umac-set-key.c
Line | Count | Source |
1 | | /* umac-set-key.c |
2 | | |
3 | | Copyright (C) 2013 Niels Möller |
4 | | |
5 | | This file is part of GNU Nettle. |
6 | | |
7 | | GNU Nettle is free software: you can redistribute it and/or |
8 | | modify it under the terms of either: |
9 | | |
10 | | * the GNU Lesser General Public License as published by the Free |
11 | | Software Foundation; either version 3 of the License, or (at your |
12 | | option) any later version. |
13 | | |
14 | | or |
15 | | |
16 | | * the GNU General Public License as published by the Free |
17 | | Software Foundation; either version 2 of the License, or (at your |
18 | | option) any later version. |
19 | | |
20 | | or both in parallel, as here. |
21 | | |
22 | | GNU Nettle is distributed in the hope that it will be useful, |
23 | | but WITHOUT ANY WARRANTY; without even the implied warranty of |
24 | | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
25 | | General Public License for more details. |
26 | | |
27 | | You should have received copies of the GNU General Public License and |
28 | | the GNU Lesser General Public License along with this program. If |
29 | | not, see http://www.gnu.org/licenses/. |
30 | | */ |
31 | | |
32 | | #if HAVE_CONFIG_H |
33 | | # include "config.h" |
34 | | #endif |
35 | | |
36 | | #include <string.h> |
37 | | |
38 | | #include "umac.h" |
39 | | #include "umac-internal.h" |
40 | | |
41 | | #include "macros.h" |
42 | | |
43 | | static void |
44 | | umac_kdf (struct aes128_ctx *aes, unsigned index, unsigned length, uint8_t *dst) |
45 | 1.84k | { |
46 | 1.84k | uint8_t block[AES_BLOCK_SIZE]; |
47 | 1.84k | uint64_t count; |
48 | 1.84k | WRITE_UINT64 (block, (uint64_t) index); |
49 | 31.9k | for (count = 1; length >= AES_BLOCK_SIZE; |
50 | 30.1k | length -= AES_BLOCK_SIZE, dst += AES_BLOCK_SIZE, count++) |
51 | 30.1k | { |
52 | 30.1k | WRITE_UINT64 (block + 8, count); |
53 | 30.1k | aes128_encrypt (aes, AES_BLOCK_SIZE, dst, block); |
54 | 30.1k | } |
55 | 1.84k | if (length > 0) |
56 | 407 | { |
57 | 407 | WRITE_UINT64 (block + 8, count); |
58 | 407 | aes128_encrypt (aes, AES_BLOCK_SIZE, block, block); |
59 | 407 | memcpy (dst, block, length); |
60 | 407 | } |
61 | 1.84k | } |
62 | | |
63 | | #if WORDS_BIGENDIAN |
64 | | #define BE_SWAP32(x) x |
65 | | #define BE_SWAP32_N(n, x) |
66 | | #else |
67 | | #define BE_SWAP32(x) \ |
68 | 96.7k | ((ROTL32(8, x) & 0x00FF00FFUL) | \ |
69 | 96.7k | (ROTL32(24, x) & 0xFF00FF00UL)) |
70 | 368 | #define BE_SWAP32_N(n, x) do { \ |
71 | 368 | unsigned be_i; \ |
72 | 97.1k | for (be_i = 0; be_i < n; be_i++) \ |
73 | 96.7k | { \ |
74 | 96.7k | uint32_t be_x = (x)[be_i]; \ |
75 | 96.7k | (x)[be_i] = BE_SWAP32 (be_x); \ |
76 | 96.7k | } \ |
77 | 368 | } while (0) |
78 | | #endif |
79 | | |
80 | | void |
81 | | _nettle_umac_set_key (uint32_t *l1_key, uint32_t *l2_key, |
82 | | uint64_t *l3_key1, uint32_t *l3_key2, |
83 | | struct aes128_ctx *aes, const uint8_t *key, unsigned n) |
84 | 368 | { |
85 | 368 | unsigned size; |
86 | 368 | uint8_t buffer[UMAC_KEY_SIZE]; |
87 | | |
88 | 368 | aes128_set_encrypt_key (aes, key); |
89 | | |
90 | 368 | size = UMAC_BLOCK_SIZE / 4 + 4*(n-1); |
91 | 368 | umac_kdf (aes, 1, size * sizeof(uint32_t), (uint8_t *) l1_key); |
92 | 368 | BE_SWAP32_N (size, l1_key); |
93 | | |
94 | 368 | size = 6*n; |
95 | 368 | umac_kdf (aes, 2, size * sizeof(uint32_t), (uint8_t *) l2_key); |
96 | 368 | _nettle_umac_l2_init (size, l2_key); |
97 | | |
98 | 368 | size = 8*n; |
99 | 368 | umac_kdf (aes, 3, size * sizeof(uint64_t), (uint8_t *) l3_key1); |
100 | 368 | _nettle_umac_l3_init (size, l3_key1); |
101 | | |
102 | | /* No need to byteswap these subkeys. */ |
103 | 368 | umac_kdf (aes, 4, n * sizeof(uint32_t), (uint8_t *) l3_key2); |
104 | | |
105 | 368 | umac_kdf (aes, 0, UMAC_KEY_SIZE, buffer); |
106 | 368 | aes128_set_encrypt_key (aes, buffer); |
107 | 368 | } |