AES added

[arm-crypto-lib.git] / bcal-ofb.c

diff --git a/bcal-ofb.c b/bcal-ofb.c
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+++ b/bcal-ofb.c
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+/* bcal-ofb.c */
+/*
+    This file is part of the ARM-Crypto-Lib.
+    Copyright (C) 2006-2010  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/>.
+*/
+
+#include <stdint.h>
+#include <string.h>
+#include "bcal-ofb.h"
+#include "bcal-basic.h"
+#include "memxor.h"
+
+
+uint8_t bcal_ofb_init(const bcdesc_t* desc, const void* key, uint16_t keysize_b, bcal_ofb_ctx_t* ctx){
+       ctx->desc = (bcdesc_t*)desc;
+       ctx->blocksize_B = (bcal_cipher_getBlocksize_b(desc)+7)/8;
+       ctx->in_block=malloc(ctx->blocksize_B);
+       if(ctx->in_block==NULL){
+                       return 0x11;
+       }
+       return bcal_cipher_init(desc, key, keysize_b, &(ctx->cctx));
+}
+
+void bcal_ofb_free(bcal_ofb_ctx_t* ctx){
+       free(ctx->in_block);
+       bcal_cipher_free(&(ctx->cctx));
+}
+
+void bcal_ofb_loadIV(const void* iv, bcal_ofb_ctx_t* ctx){
+       if(iv){
+               memcpy(ctx->in_block, iv, ctx->blocksize_B);
+       }
+}
+
+void bcal_ofb_encNext(void* block, bcal_ofb_ctx_t* ctx){
+       bcal_cipher_enc(ctx->in_block , &(ctx->cctx));
+       memxor(block, ctx->in_block, ctx->blocksize_B);
+}
+
+void bcal_ofb_decNext(void* block, bcal_ofb_ctx_t* ctx){
+       bcal_cipher_enc(ctx->in_block , &(ctx->cctx));
+       memxor(block, ctx->in_block, ctx->blocksize_B);
+}
+
+
+void bcal_ofb_encMsg(const void* iv, void* msg, uint32_t msg_len_b, bcal_ofb_ctx_t* ctx){
+       uint16_t block_len_b;
+       block_len_b = ctx->blocksize_B*8;
+       bcal_ofb_loadIV(iv, ctx);
+       while(msg_len_b>block_len_b){
+               bcal_ofb_encNext(msg, ctx);
+               msg_len_b -= block_len_b;
+               msg = (uint8_t*)msg + ctx->blocksize_B;
+       }
+       bcal_cipher_enc(ctx->in_block, &(ctx->cctx));
+       ctx->in_block[msg_len_b/8] = 0xff00>>(msg_len_b&7);
+       memxor(msg, ctx->in_block, (msg_len_b+7)/8);
+}
+
+void bcal_ofb_decMsg(const void* iv, void* msg, uint32_t msg_len_b, bcal_ofb_ctx_t* ctx){
+       bcal_ofb_encMsg(iv, msg, msg_len_b, ctx);
+}
+