arm-crypto-lib/bcal/bcal-cfb_byte.c

89 lines
2.7 KiB
C

/* bcal-cfb_byte.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-cfb_byte.h"
#include "bcal-basic.h"
#include "memxor.h"
uint8_t bcal_cfb_B_init(const bcdesc_t* desc, const void* key, uint16_t keysize_b, uint16_t size_b, bcal_cfb_B_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;
}
if(size_b&7){
return 0x12;
}
ctx->size_B = size_b/8;
return bcal_cipher_init(desc, key, keysize_b, &(ctx->cctx));
}
void bcal_cfb_B_free(bcal_cfb_B_ctx_t* ctx){
free(ctx->in_block);
bcal_cipher_free(&(ctx->cctx));
}
void bcal_cfb_B_loadIV(const void* iv, bcal_cfb_B_ctx_t* ctx){
if(iv){
memcpy(ctx->in_block, iv, ctx->blocksize_B);
}
}
void bcal_cfb_B_encNext(void* block, bcal_cfb_B_ctx_t* ctx){
uint8_t tmp[ctx->blocksize_B];
memcpy(tmp, ctx->in_block, ctx->blocksize_B);
bcal_cipher_enc(tmp, &(ctx->cctx));
memxor(block, tmp, ctx->size_B);
memmove(ctx->in_block, ctx->in_block+ctx->size_B, ctx->blocksize_B - ctx->size_B);
memcpy(ctx->in_block+ctx->blocksize_B-ctx->size_B, block, ctx->size_B);
}
void bcal_cfb_B_decNext(void* block, bcal_cfb_B_ctx_t* ctx){
uint8_t tmp[ctx->blocksize_B];
uint8_t xblock[ctx->size_B];
memcpy(xblock, block, ctx->size_B);
memcpy(tmp, ctx->in_block, ctx->blocksize_B);
bcal_cipher_enc(tmp, &(ctx->cctx));
memxor(block, tmp, ctx->size_B);
memmove(ctx->in_block, ctx->in_block+ctx->size_B, ctx->blocksize_B - ctx->size_B);
memcpy(ctx->in_block+ctx->blocksize_B-ctx->size_B, xblock, ctx->size_B);
}
void bcal_cfb_B_encMsg(const void* iv, void* msg, uint16_t msg_blocks, bcal_cfb_B_ctx_t* ctx){
bcal_cfb_B_loadIV(iv, ctx);
while(msg_blocks--){
bcal_cfb_B_encNext(msg, ctx);
msg = (uint8_t*)msg+ctx->size_B;
}
}
void bcal_cfb_B_decMsg(const void* iv, void* msg, uint16_t msg_blocks, bcal_cfb_B_ctx_t* ctx){
bcal_cfb_B_loadIV(iv, ctx);
while(msg_blocks--){
bcal_cfb_B_decNext(msg, ctx);
msg = (uint8_t*)msg+ctx->size_B;
}
}