4 Copyright (C) Stefan Metzmacher 2012
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #include "../lib/crypto/crypto.h"
22 #include "lib/util/byteorder.h"
24 #define M_ ((AES_CCM_128_M - 2) / 2)
25 #define L_ (AES_CCM_128_L - 1)
27 static inline void aes_ccm_128_xor(const uint8_t in1[AES_BLOCK_SIZE],
28 const uint8_t in2[AES_BLOCK_SIZE],
29 uint8_t out[AES_BLOCK_SIZE])
33 for (i = 0; i < AES_BLOCK_SIZE; i++) {
34 out[i] = in1[i] ^ in2[i];
38 void aes_ccm_128_init(struct aes_ccm_128_context *ctx,
39 const uint8_t K[AES_BLOCK_SIZE],
40 const uint8_t N[AES_CCM_128_NONCE_SIZE],
41 size_t a_total, size_t m_total)
43 uint8_t B_0[AES_BLOCK_SIZE];
47 AES_set_encrypt_key(K, 128, &ctx->aes_key);
48 memcpy(ctx->nonce, N, AES_CCM_128_NONCE_SIZE);
49 ctx->a_remain = a_total;
50 ctx->m_remain = m_total;
60 memcpy(&B_0[1], ctx->nonce, AES_CCM_128_NONCE_SIZE);
61 RSIVAL(B_0, (AES_BLOCK_SIZE - AES_CCM_128_L), m_total);
66 AES_encrypt(B_0, ctx->X_i, &ctx->aes_key);
71 if (a_total >= UINT32_MAX) {
72 RSSVAL(ctx->B_i, 0, 0xFFFF);
73 RSBVAL(ctx->B_i, 2, (uint64_t)a_total);
75 } else if (a_total >= 0xFF00) {
76 RSSVAL(ctx->B_i, 0, 0xFFFE);
77 RSIVAL(ctx->B_i, 2, a_total);
79 } else if (a_total > 0) {
80 RSSVAL(ctx->B_i, 0, a_total);
84 ctx->S_i_ofs = AES_BLOCK_SIZE;
87 void aes_ccm_128_update(struct aes_ccm_128_context *ctx,
88 const uint8_t *v, size_t v_len)
92 if (ctx->a_remain > 0) {
93 remain = &ctx->a_remain;
95 remain = &ctx->m_remain;
99 size_t n = MIN(AES_BLOCK_SIZE - ctx->B_i_ofs, v_len);
102 memcpy(&ctx->B_i[ctx->B_i_ofs], v, n);
108 if (ctx->B_i_ofs == AES_BLOCK_SIZE) {
110 } else if (*remain == 0) {
118 aes_ccm_128_xor(ctx->X_i, ctx->B_i, ctx->B_i);
119 AES_encrypt(ctx->B_i, ctx->X_i, &ctx->aes_key);
121 ZERO_STRUCT(ctx->B_i);
126 static void aes_ccm_128_S_i(struct aes_ccm_128_context *ctx,
127 uint8_t S_i[AES_BLOCK_SIZE],
130 uint8_t A_i[AES_BLOCK_SIZE];
133 memcpy(&A_i[1], ctx->nonce, AES_CCM_128_NONCE_SIZE);
134 RSIVAL(A_i, (AES_BLOCK_SIZE - AES_CCM_128_L), i);
136 AES_encrypt(A_i, S_i, &ctx->aes_key);
139 void aes_ccm_128_crypt(struct aes_ccm_128_context *ctx,
140 uint8_t *m, size_t m_len)
143 if (ctx->S_i_ofs == AES_BLOCK_SIZE) {
145 aes_ccm_128_S_i(ctx, ctx->S_i, ctx->S_i_ctr);
149 m[0] ^= ctx->S_i[ctx->S_i_ofs];
156 void aes_ccm_128_digest(struct aes_ccm_128_context *ctx,
157 uint8_t digest[AES_BLOCK_SIZE])
159 uint8_t S_0[AES_BLOCK_SIZE];
161 aes_ccm_128_S_i(ctx, S_0, 0);
166 aes_ccm_128_xor(ctx->X_i, S_0, digest);