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
30 #include "aes_keyschedule.h"
35 void aes_rotword(void* a){
38 ((uint8_t*)a)[0] = ((uint8_t*)a)[1];
39 ((uint8_t*)a)[1] = ((uint8_t*)a)[2];
40 ((uint8_t*)a)[2] = ((uint8_t*)a)[3];
44 uint8_t rc_tab[] = { 0x01, 0x02, 0x04, 0x08,
45 0x10, 0x20, 0x40, 0x80,
48 void aes_init(const void* key, uint16_t keysize_b, aes_genctx_t* ctx){
49 uint8_t hi,i,nk, next_nk;
55 nk=keysize_b>>5; /* 4, 6, 8 */
57 memcpy(ctx, key, keysize_b/8);
60 tmp.v32 = ((uint32_t*)(ctx->key[0].ks))[i-1];
63 tmp.v8[0] = aes_sbox[tmp.v8[0]];
64 tmp.v8[1] = aes_sbox[tmp.v8[1]];
65 tmp.v8[2] = aes_sbox[tmp.v8[2]];
66 tmp.v8[3] = aes_sbox[tmp.v8[3]];
70 aes_rotword(&(tmp.v32));
71 tmp.v8[0] = aes_sbox[tmp.v8[0]];
72 tmp.v8[1] = aes_sbox[tmp.v8[1]];
73 tmp.v8[2] = aes_sbox[tmp.v8[2]];
74 tmp.v8[3] = aes_sbox[tmp.v8[3]];
75 tmp.v8[0] ^= rc_tab[rc];
78 ((uint32_t*)(ctx->key[0].ks))[i] = ((uint32_t*)(ctx->key[0].ks))[i-nk]
83 void aes128_init(const void* key, aes128_ctx_t* ctx){
84 aes_init(key, 128, (aes_genctx_t*)ctx);
87 void aes192_init(const void* key, aes192_ctx_t* ctx){
88 aes_init(key, 192, (aes_genctx_t*)ctx);
91 void aes256_init(const void* key, aes256_ctx_t* ctx){
92 aes_init(key, 256, (aes_genctx_t*)ctx);