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 umac64_set_key (struct umac64_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, 2);
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 umac64_set_nonce (struct umac64_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] & 1;
70 ctx->nonce[nonce_length - 1] &= ~1;
71 ctx->nonce_length = nonce_length;
74 #define UMAC64_BLOCK(ctx, block) do { \
75 uint64_t __umac64_y[2]; \
76 _umac_nh_n (__umac64_y, 2, ctx->l1_key, UMAC_BLOCK_SIZE, block); \
77 __umac64_y[0] += 8*UMAC_BLOCK_SIZE; \
78 __umac64_y[1] += 8*UMAC_BLOCK_SIZE; \
79 _umac_l2 (ctx->l2_key, ctx->l2_state, 2, ctx->count++, __umac64_y); \
83 umac64_update (struct umac64_ctx *ctx,
84 size_t length, const uint8_t *data)
86 MD_UPDATE (ctx, length, data, UMAC64_BLOCK, (void)0);
91 umac64_digest (struct umac64_ctx *ctx,
92 size_t length, uint8_t *digest)
100 if (ctx->index > 0 || ctx->count == 0)
102 /* Zero pad to multiple of 32 */
104 unsigned pad = (ctx->index > 0) ? 31 & - ctx->index : 32;
105 memset (ctx->block + ctx->index, 0, pad);
107 _umac_nh_n (y, 2, ctx->l1_key, ctx->index + pad, ctx->block);
108 y[0] += 8 * ctx->index;
109 y[1] += 8 * ctx->index;
110 _umac_l2 (ctx->l2_key, ctx->l2_state, 2, ctx->count++, y);
112 assert (ctx->count > 0);
113 if ( !(ctx->nonce_low & _UMAC_NONCE_CACHED))
115 aes128_encrypt (&ctx->pdf_key, AES_BLOCK_SIZE,
116 (uint8_t *) ctx->pad_cache, ctx->nonce);
117 ctx->nonce_low |= _UMAC_NONCE_CACHED;
119 pad = ctx->pad_cache + 2*(ctx->nonce_low & 1);
121 /* Increment nonce */
123 if ( !(ctx->nonce_low & 1))
125 unsigned i = ctx->nonce_length - 1;
130 if (ctx->nonce[i] == 0 && i > 0)
131 INCREMENT (i, ctx->nonce);
134 _umac_l2_final (ctx->l2_key, ctx->l2_state, 2, ctx->count);
135 tag[0] = pad[0] ^ ctx->l3_key2[0] ^ _umac_l3 (ctx->l3_key1,
137 tag[1] = pad[1] ^ ctx->l3_key2[1] ^ _umac_l3 (ctx->l3_key1 + 8,
139 memcpy (digest, tag, length);
142 ctx->count = ctx->index = 0;