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"
27 uint8_t bcal_ofb_init(const bcdesc_t* desc, const void* key, uint16_t keysize_b, bcal_ofb_ctx_t* ctx){
28 ctx->desc = (bcdesc_t*)desc;
29 ctx->blocksize_B = (bcal_cipher_getBlocksize_b(desc)+7)/8;
30 ctx->in_block=malloc(ctx->blocksize_B);
31 if(ctx->in_block==NULL){
34 return bcal_cipher_init(desc, key, keysize_b, &(ctx->cctx));
37 void bcal_ofb_free(bcal_ofb_ctx_t* ctx){
39 bcal_cipher_free(&(ctx->cctx));
42 void bcal_ofb_loadIV(const void* iv, bcal_ofb_ctx_t* ctx){
44 memcpy(ctx->in_block, iv, ctx->blocksize_B);
48 void bcal_ofb_encNext(void* block, bcal_ofb_ctx_t* ctx){
49 bcal_cipher_enc(ctx->in_block , &(ctx->cctx));
50 memxor(block, ctx->in_block, ctx->blocksize_B);
53 void bcal_ofb_decNext(void* block, bcal_ofb_ctx_t* ctx){
54 bcal_cipher_enc(ctx->in_block , &(ctx->cctx));
55 memxor(block, ctx->in_block, ctx->blocksize_B);
59 void bcal_ofb_encMsg(const void* iv, void* msg, uint32_t msg_len_b, bcal_ofb_ctx_t* ctx){
61 block_len_b = ctx->blocksize_B*8;
62 bcal_ofb_loadIV(iv, ctx);
63 while(msg_len_b>block_len_b){
64 bcal_ofb_encNext(msg, ctx);
65 msg_len_b -= block_len_b;
66 msg = (uint8_t*)msg + ctx->blocksize_B;
68 bcal_cipher_enc(ctx->in_block, &(ctx->cctx));
69 ctx->in_block[msg_len_b/8] = 0xff00>>(msg_len_b&7);
70 memxor(msg, ctx->in_block, (msg_len_b+7)/8);
73 void bcal_ofb_decMsg(const void* iv, void* msg, uint32_t msg_len_b, bcal_ofb_ctx_t* ctx){
74 bcal_ofb_encMsg(iv, msg, msg_len_b, ctx);