3 Copyright (C) 2013 Niels Möller
5 This file is part of GNU Nettle.
7 GNU Nettle is free software: you can redistribute it and/or
8 modify it under the terms of either:
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.
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.
20 or both in parallel, as here.
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.
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/.
44 umac64_set_key (struct umac64_ctx *ctx, const uint8_t *key)
46 _umac_set_key (ctx->l1_key, ctx->l2_key, ctx->l3_key1, ctx->l3_key2,
47 &ctx->pdf_key, key, 2);
50 memset (ctx->nonce, 0, sizeof(ctx->nonce));
52 ctx->nonce_length = sizeof(ctx->nonce);
54 /* Initialize buffer */
55 ctx->count = ctx->index = 0;
59 umac64_set_nonce (struct umac64_ctx *ctx,
60 size_t nonce_length, const uint8_t *nonce)
62 assert (nonce_length > 0);
63 assert (nonce_length <= AES_BLOCK_SIZE);
65 memcpy (ctx->nonce, nonce, nonce_length);
66 memset (ctx->nonce + nonce_length, 0, AES_BLOCK_SIZE - nonce_length);
68 ctx->nonce_low = ctx->nonce[nonce_length - 1] & 1;
69 ctx->nonce[nonce_length - 1] &= ~1;
70 ctx->nonce_length = nonce_length;
73 #define UMAC64_BLOCK(ctx, block) do { \
74 uint64_t __umac64_y[2]; \
75 _umac_nh_n (__umac64_y, 2, ctx->l1_key, UMAC_DATA_SIZE, block); \
76 __umac64_y[0] += 8*UMAC_DATA_SIZE; \
77 __umac64_y[1] += 8*UMAC_DATA_SIZE; \
78 _umac_l2 (ctx->l2_key, ctx->l2_state, 2, ctx->count++, __umac64_y); \
82 umac64_update (struct umac64_ctx *ctx,
83 size_t length, const uint8_t *data)
85 MD_UPDATE (ctx, length, data, UMAC64_BLOCK, (void)0);
90 umac64_digest (struct umac64_ctx *ctx,
91 size_t length, uint8_t *digest)
99 if (ctx->index > 0 || ctx->count == 0)
101 /* Zero pad to multiple of 32 */
103 unsigned pad = (ctx->index > 0) ? 31 & - ctx->index : 32;
104 memset (ctx->block + ctx->index, 0, pad);
106 _umac_nh_n (y, 2, ctx->l1_key, ctx->index + pad, ctx->block);
107 y[0] += 8 * ctx->index;
108 y[1] += 8 * ctx->index;
109 _umac_l2 (ctx->l2_key, ctx->l2_state, 2, ctx->count++, y);
111 assert (ctx->count > 0);
112 if ( !(ctx->nonce_low & _UMAC_NONCE_CACHED))
114 aes128_encrypt (&ctx->pdf_key, AES_BLOCK_SIZE,
115 (uint8_t *) ctx->pad_cache, ctx->nonce);
116 ctx->nonce_low |= _UMAC_NONCE_CACHED;
118 pad = ctx->pad_cache + 2*(ctx->nonce_low & 1);
120 /* Increment nonce */
122 if ( !(ctx->nonce_low & 1))
124 unsigned i = ctx->nonce_length - 1;
129 if (ctx->nonce[i] == 0 && i > 0)
130 INCREMENT (i, ctx->nonce);
133 _umac_l2_final (ctx->l2_key, ctx->l2_state, 2, ctx->count);
134 tag[0] = pad[0] ^ ctx->l3_key2[0] ^ _umac_l3 (ctx->l3_key1,
136 tag[1] = pad[1] ^ ctx->l3_key2[1] ^ _umac_l3 (ctx->l3_key1 + 8,
138 memcpy (digest, tag, length);
141 ctx->count = ctx->index = 0;