X-Git-Url: https://git.cryptolib.org/?p=avr-crypto-lib.git;a=blobdiff_plain;f=aes%2Faes_keyschedule.c;fp=aes%2Faes_keyschedule.c;h=9e58eb578320de6ae738aa34cad0b521d487fb3a;hp=0000000000000000000000000000000000000000;hb=4f50c75ee5a6cc88bf7ea71957ed509e298e6c25;hpb=7701e318e4e2bac7f84dbf6e368f1501814948fc

diff --git a/aes/aes_keyschedule.c b/aes/aes_keyschedule.c
new file mode 100644
index 0000000..9e58eb5
--- /dev/null
+++ b/aes/aes_keyschedule.c
@@ -0,0 +1,91 @@
+/* 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);
+}