3 This file is part of the AVR-Crypto-Lib.
4 Copyright (C) 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/>.
23 #include "bcal-basic.h"
26 uint8_t bcal_cbc_init(const bcdesc_t* desc, const void* key, uint16_t keysize_b, bcal_cbc_ctx_t* ctx){
27 ctx->desc = (bcdesc_t*)desc;
28 ctx->blocksize_B = (bcal_cipher_getBlocksize_b(desc)+7)/8;
29 ctx->prev_block = malloc(ctx->blocksize_B);
31 if(ctx->prev_block == NULL){
34 return bcal_cipher_init(desc, key, keysize_b, &(ctx->cctx));
37 void bcal_cbc_free(bcal_cbc_ctx_t* ctx){
38 bcal_cipher_free(&(ctx->cctx));
39 free(ctx->prev_block);
43 void bcal_cbc_loadIV(const void* iv, bcal_cbc_ctx_t* ctx){
45 memcpy(ctx->prev_block, iv, ctx->blocksize_B);
49 void bcal_cbc_encNext(void* block, bcal_cbc_ctx_t* ctx){
50 memxor(block, ctx->prev_block, ctx->blocksize_B);
51 bcal_cipher_enc(block, &(ctx->cctx));
52 memcpy(ctx->prev_block, block, ctx->blocksize_B);
55 void bcal_cbc_decNext(void* block, bcal_cbc_ctx_t* ctx){
56 uint8_t tmp[ctx->blocksize_B];
57 memcpy(tmp, block, ctx->blocksize_B);
58 bcal_cipher_dec(block, &(ctx->cctx));
59 memxor(block, ctx->prev_block, ctx->blocksize_B);
60 memcpy(ctx->prev_block, tmp, ctx->blocksize_B);
62 void bcal_cbc_decRand(void* block, const void* prev_block, bcal_cbc_ctx_t* ctx){
63 bcal_cipher_dec(block, &(ctx->cctx));
64 memxor(block, prev_block, ctx->blocksize_B);
67 void bcal_cbc_encMsg(const void* iv, void* msg, uint16_t msg_blocks, bcal_cbc_ctx_t* ctx){
68 bcal_cbc_loadIV(iv, ctx);
70 bcal_cbc_encNext(msg, ctx);
71 msg = (uint8_t*)msg + ctx->blocksize_B;
75 void bcal_cbc_decMsg(const void* iv, void* msg, uint16_t msg_blocks, bcal_cbc_ctx_t* ctx){
76 msg=(uint8_t*)msg + (msg_blocks-1)*ctx->blocksize_B;
77 while(msg_blocks > 1){
78 bcal_cbc_decRand(msg, (uint8_t*)msg-ctx->blocksize_B, ctx);
80 msg=(uint8_t*)msg-ctx->blocksize_B;
82 bcal_cbc_decRand(msg, iv, ctx);