1 /* aes_keyschedule.c */
3 This file is part of the ARM-Crypto-Lib.
4 Copyright (C) 2006-2010 Daniel Otte (daniel.otte@rub.de)
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/>.
20 * \file aes_keyschedule.c
21 * \email daniel.otte@rub.de
24 * \license GPLv3 or later
32 #include "aes_keyschedule.h"
37 void aes_rotword(void* a){
40 ((uint8_t*)a)[0] = ((uint8_t*)a)[1];
41 ((uint8_t*)a)[1] = ((uint8_t*)a)[2];
42 ((uint8_t*)a)[2] = ((uint8_t*)a)[3];
47 const uint8_t rc_tab[] = {
48 0x01, 0x02, 0x04, 0x08,
49 0x10, 0x20, 0x40, 0x80,
52 void aes_init(const void* key, uint16_t keysize_b, aes_genctx_t* ctx){
53 uint8_t hi,i,nk, next_nk;
55 union __attribute__((packed)) {
59 nk = keysize_b >> 5; /* 4, 6, 8 */
60 hi = 4 * (nk + 6 + 1);
61 memcpy(ctx, key, keysize_b/8);
64 /* tmp.v32 = ((uint32_t*)(ctx->key[0].ks))[i-1]; */
65 memcpy(tmp.v8, ctx->key[0].ks + (i - 1) * 4, 4);
67 if(nk == 8 && i % 8 == 4){
68 tmp.v8[0] = aes_sbox[tmp.v8[0]];
69 tmp.v8[1] = aes_sbox[tmp.v8[1]];
70 tmp.v8[2] = aes_sbox[tmp.v8[2]];
71 tmp.v8[3] = aes_sbox[tmp.v8[3]];
75 /* aes_rotword(&(tmp.v32)); */
76 tmp.v32 = (tmp.v32 >> 8) | (tmp.v32 << 24);
77 tmp.v8[0] = aes_sbox[tmp.v8[0]];
78 tmp.v8[1] = aes_sbox[tmp.v8[1]];
79 tmp.v8[2] = aes_sbox[tmp.v8[2]];
80 tmp.v8[3] = aes_sbox[tmp.v8[3]];
81 tmp.v8[0] ^= rc_tab[rc];
84 memcpy(ctx->key[0].ks + 4 * i, ctx->key[0].ks + (i - nk) * 4, 4);
85 memxor(ctx->key[0].ks + 4 * i, tmp.v8, 4);
87 ((uint32_t*)(ctx->key[0].ks))[i] = ((uint32_t*)(ctx->key[0].ks))[i-nk]
93 void aes128_init(const void* key, aes128_ctx_t* ctx){
94 aes_init(key, 128, (aes_genctx_t*)ctx);
97 void aes192_init(const void* key, aes192_ctx_t* ctx){
98 aes_init(key, 192, (aes_genctx_t*)ctx);
101 void aes256_init(const void* key, aes256_ctx_t* ctx){
102 aes_init(key, 256, (aes_genctx_t*)ctx);