forgotten directories

[avr-crypto-lib.git] / bcal / bcal-cbc.c

diff --git a/bcal/bcal-cbc.c b/bcal/bcal-cbc.c
new file mode 100644 (file)
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+/* bcal-cbc.c */
+/*
+    This file is part of the AVR-Crypto-Lib.
+    Copyright (C) 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-cbc.h"
+#include "bcal-basic.h"
+#include "memxor/memxor.h"
+
+uint8_t bcal_cbc_init(const bcdesc_t* desc, const void* key, uint16_t keysize_b, bcal_cbc_ctx_t* ctx){
+       ctx->desc = (bcdesc_t*)desc;
+       ctx->blocksize_B = (bcal_cipher_getBlocksize_b(desc)+7)/8;
+       ctx->prev_block = malloc(ctx->blocksize_B);
+
+       if(ctx->prev_block==NULL){
+               return 0x11;
+       }
+       return bcal_cipher_init(desc, key, keysize_b, &(ctx->cctx));
+}
+
+void bcal_cbc_free(bcal_cbc_ctx_t* ctx){
+       bcal_cipher_free(&(ctx->cctx));
+       free(ctx->prev_block);
+}
+
+
+void bcal_cbc_loadIV(const void* iv, bcal_cbc_ctx_t* ctx){
+       if(iv){
+               memcpy(ctx->prev_block, iv, ctx->blocksize_B);
+       }
+}
+
+void bcal_cbc_encNext(void* block, bcal_cbc_ctx_t* ctx){
+       memxor(block, ctx->prev_block, ctx->blocksize_B);
+       bcal_cipher_enc(block, &(ctx->cctx));
+       memcpy(ctx->prev_block, block, ctx->blocksize_B);
+}
+
+void bcal_cbc_decNext(void* block, bcal_cbc_ctx_t* ctx){
+       uint8_t tmp[ctx->blocksize_B];
+       memcpy(tmp, block, ctx->blocksize_B);
+       bcal_cipher_dec(block, &(ctx->cctx));
+       memxor(block, ctx->prev_block, ctx->blocksize_B);
+       memcpy(ctx->prev_block, tmp, ctx->blocksize_B);
+}
+void bcal_cbc_decRand(void* block, const void* prev_block, bcal_cbc_ctx_t* ctx){
+       bcal_cipher_dec(block, &(ctx->cctx));
+       memxor(block, prev_block, ctx->blocksize_B);
+}
+
+void bcal_cbc_encMsg(const void* iv, void* msg, uint16_t msg_blocks, bcal_cbc_ctx_t* ctx){
+       bcal_cbc_loadIV(iv, ctx);
+       while(msg_blocks--){
+               bcal_cbc_encNext(msg, ctx);
+               msg = (uint8_t*)msg + ctx->blocksize_B;
+       }
+}
+
+void bcal_cbc_decMsg(const void* iv, void* msg, uint16_t msg_blocks, bcal_cbc_ctx_t* ctx){
+       msg=(uint8_t*)msg + (msg_blocks-1)*ctx->blocksize_B;
+       while(msg_blocks > 1){
+               bcal_cbc_decRand(msg, (uint8_t*)msg-ctx->blocksize_B, ctx);
+               msg_blocks -= 1;
+               msg=(uint8_t*)msg-ctx->blocksize_B;
+       }
+       bcal_cbc_decRand(msg, iv, ctx);
+}
+