+/* aes_keyschedule.c */
+/*
+ This file is part of the AVR-Crypto-Lib.
+ Copyright (C) 2008, 2009 Daniel Otte (daniel.otte@rub.de)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * \file aes_keyschedule.c
+ * \email daniel.otte@rub.de
+ * \author Daniel Otte
+ * \date 2008-12-30
+ * \license GPLv3 or later
+ *
+ */
+
+#include <stdint.h>
+#include "aes.h"
+#include "aes_keyschedule.h"
+#include "aes_sbox.h"
+#include <string.h>
+#include <avr/pgmspace.h>
+
+static
+void aes_rotword(void* a){
+ uint8_t t;
+ t=((uint8_t*)a)[0];
+ ((uint8_t*)a)[0] = ((uint8_t*)a)[1];
+ ((uint8_t*)a)[1] = ((uint8_t*)a)[2];
+ ((uint8_t*)a)[2] = ((uint8_t*)a)[3];
+ ((uint8_t*)a)[3] = t;
+}
+
+uint8_t rc_tab[] PROGMEM = { 0x01, 0x02, 0x04, 0x08,
+ 0x10, 0x20, 0x40, 0x80,
+ 0x1b, 0x36 };
+
+void aes_init(const void* key, uint16_t keysize_b, aes_genctx_t* ctx){
+ uint8_t hi,i,nk, next_nk;
+ uint8_t rc=0;
+ uint8_t tmp[4];
+ nk=keysize_b>>5; /* 4, 6, 8 */
+ hi=4*(nk+6+1);
+ memcpy(ctx, key, keysize_b/8);
+ next_nk = nk;
+ for(i=nk;i<hi;++i){
+ *((uint32_t*)tmp) = ((uint32_t*)(ctx->key[0].ks))[i-1];
+ if(i!=next_nk){
+ if(nk==8 && i%8==4){
+ tmp[0] = pgm_read_byte(aes_sbox+tmp[0]);
+ tmp[1] = pgm_read_byte(aes_sbox+tmp[1]);
+ tmp[2] = pgm_read_byte(aes_sbox+tmp[2]);
+ tmp[3] = pgm_read_byte(aes_sbox+tmp[3]);
+ }
+ } else {
+ next_nk += nk;
+ aes_rotword(tmp);
+ tmp[0] = pgm_read_byte(aes_sbox+tmp[0]);
+ tmp[1] = pgm_read_byte(aes_sbox+tmp[1]);
+ tmp[2] = pgm_read_byte(aes_sbox+tmp[2]);
+ tmp[3] = pgm_read_byte(aes_sbox+tmp[3]);
+ tmp[0] ^= pgm_read_byte(rc_tab+rc);
+ rc++;
+ }
+ ((uint32_t*)(ctx->key[0].ks))[i] = ((uint32_t*)(ctx->key[0].ks))[i-nk]
+ ^ *((uint32_t*)tmp);
+ }
+}
+
+void aes128_init(const void* key, aes128_ctx_t* ctx){
+ aes_init(key, 128, (aes_genctx_t*)ctx);
+}
+
+void aes192_init(const void* key, aes192_ctx_t* ctx){
+ aes_init(key, 192, (aes_genctx_t*)ctx);
+}
+
+void aes256_init(const void* key, aes256_ctx_t* ctx){
+ aes_init(key, 256, (aes_genctx_t*)ctx);
+}