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/.
40 #include "umac-internal.h"
45 umac32_set_key (struct umac32_ctx *ctx, const uint8_t *key)
47 _umac_set_key (ctx->l1_key, ctx->l2_key, ctx->l3_key1, ctx->l3_key2,
48 &ctx->pdf_key, key, 1);
51 memset (ctx->nonce, 0, sizeof(ctx->nonce));
53 ctx->nonce_length = sizeof(ctx->nonce);
55 /* Initialize buffer */
56 ctx->count = ctx->index = 0;
60 umac32_set_nonce (struct umac32_ctx *ctx,
61 size_t nonce_length, const uint8_t *nonce)
63 assert (nonce_length > 0);
64 assert (nonce_length <= AES_BLOCK_SIZE);
66 memcpy (ctx->nonce, nonce, nonce_length);
67 memset (ctx->nonce + nonce_length, 0, AES_BLOCK_SIZE - nonce_length);
69 ctx->nonce_low = ctx->nonce[nonce_length - 1] & 3;
70 ctx->nonce[nonce_length - 1] &= ~3;
71 ctx->nonce_length = nonce_length;
74 #define UMAC32_BLOCK(ctx, block) do { \
76 = _umac_nh (ctx->l1_key, UMAC_BLOCK_SIZE, block) \
77 + 8*UMAC_BLOCK_SIZE ; \
78 _umac_l2 (ctx->l2_key, ctx->l2_state, 1, ctx->count++, &__umac32_y); \
82 umac32_update (struct umac32_ctx *ctx,
83 size_t length, const uint8_t *data)
85 MD_UPDATE (ctx, length, data, UMAC32_BLOCK, (void)0);
90 umac32_digest (struct umac32_ctx *ctx,
91 size_t length, uint8_t *digest)
98 if (ctx->index > 0 || ctx->count == 0)
100 /* Zero pad to multiple of 32 */
102 unsigned pad = (ctx->index > 0) ? 31 & - ctx->index : 32;
103 memset (ctx->block + ctx->index, 0, pad);
105 y = _umac_nh (ctx->l1_key, ctx->index + pad, ctx->block)
107 _umac_l2 (ctx->l2_key, ctx->l2_state, 1, ctx->count++, &y);
109 assert (ctx->count > 0);
110 if ( !(ctx->nonce_low & _UMAC_NONCE_CACHED))
112 aes128_encrypt (&ctx->pdf_key, AES_BLOCK_SIZE,
113 (uint8_t *) ctx->pad_cache, ctx->nonce);
114 ctx->nonce_low |= _UMAC_NONCE_CACHED;
117 pad = ctx->pad_cache[ctx->nonce_low & 3];
119 /* Increment nonce */
121 if ( !(ctx->nonce_low & 3))
123 unsigned i = ctx->nonce_length - 1;
128 if (ctx->nonce[i] == 0 && i > 0)
129 INCREMENT (i, ctx->nonce);
132 _umac_l2_final (ctx->l2_key, ctx->l2_state, 1, ctx->count);
133 pad ^= ctx->l3_key2[0] ^ _umac_l3 (ctx->l3_key1, ctx->l2_state);
134 memcpy (digest, &pad, length);
137 ctx->count = ctx->index = 0;