]> git.cryptolib.org Git - arm-crypto-lib.git/blobdiff - bcal/bcal-cfb_bit.c
updated build system
[arm-crypto-lib.git] / bcal / bcal-cfb_bit.c
diff --git a/bcal/bcal-cfb_bit.c b/bcal/bcal-cfb_bit.c
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+/* bcal-cfb_bit.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_bit.h"
+#include "bcal-basic.h"
+
+static uint8_t read_bit(void* block, uint32_t index){
+       uint8_t r;
+       r=((uint8_t*)block)[index/8];
+       r=(r&(0x80>>(index&7)))?0xff:0x00;
+       return r;
+}
+
+static void write_bit(void* block, uint32_t index, uint8_t value){
+       if(value){
+               /* set bit */
+               ((uint8_t*)block)[index/8] |= 0x80>>(index&7);
+       }else{
+               /* clear bit */
+               ((uint8_t*)block)[index/8] &= ~(0x80>>(index&7));
+       }
+}
+
+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>bcal_cipher_getBlocksize_b(desc)){
+               return 0x12;
+       }
+       ctx->size_b = size_b;
+       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, uint8_t offset, bcal_cfb_b_ctx_t* ctx){
+       uint8_t tmp[ctx->blocksize_B];
+       offset &= 7;
+       memcpy(tmp, ctx->in_block, ctx->blocksize_B);
+       bcal_cipher_enc(tmp, &(ctx->cctx));
+       uint16_t i,j;
+       uint8_t a;
+       for(i=0; i<ctx->blocksize_B*8-ctx->size_b; ++i){
+               a = read_bit(ctx->in_block, i+ctx->size_b);
+               write_bit(ctx->in_block, i, a);
+       }
+       for(j=offset,i=0; i<ctx->size_b; ++i, ++j){
+               a = read_bit(tmp, i) ^ read_bit(block, j);
+               write_bit(ctx->in_block, ctx->blocksize_B*8-ctx->size_b+i, a);
+               write_bit(block, j, a);
+       }
+}
+
+void bcal_cfb_b_decNext(void* block, uint8_t offset, bcal_cfb_b_ctx_t* ctx){
+       uint8_t tmp[ctx->blocksize_B];
+       offset &= 7;
+       memcpy(tmp, ctx->in_block, ctx->blocksize_B);
+       bcal_cipher_enc(tmp, &(ctx->cctx));
+       uint16_t i,j;
+       uint8_t a,b;
+       for(i=0; i<ctx->blocksize_B*8-ctx->size_b; ++i){
+               a = read_bit(ctx->in_block, i+ctx->size_b);
+               write_bit(ctx->in_block, i, a);
+       }
+       for(j=offset,i=0; i<ctx->size_b; ++i, ++j){
+               a = read_bit(tmp, i);
+               b = read_bit(block, j);
+               a ^= b;
+               write_bit(ctx->in_block, ctx->blocksize_B*8-ctx->size_b+i, b);
+               write_bit(block, j, a);
+       }
+}
+
+void bcal_cfb_b_encMsg(const void* iv, void* msg, uint8_t offset, uint32_t msg_blocks, bcal_cfb_b_ctx_t* ctx){
+       bcal_cfb_b_loadIV(iv, ctx);
+       uint64_t addr;
+       addr = ((uint32_t)msg)*8+offset;
+       while(msg_blocks--){
+               msg = (void*)((uint32_t)(addr/8));
+               offset = addr&7;
+               bcal_cfb_b_encNext(msg, offset, ctx);
+               addr += ctx->size_b;
+       }
+}
+
+void bcal_cfb_b_decMsg(const void* iv, void* msg, uint8_t offset, uint32_t msg_blocks, bcal_cfb_b_ctx_t* ctx){
+       bcal_cfb_b_loadIV(iv, ctx);
+       uint64_t addr;
+       addr = ((uint32_t)msg)*8+offset;
+       while(msg_blocks--){
+               msg = (void*)((uint32_t)(addr/8));
+               offset = addr&7;
+               bcal_cfb_b_decNext(msg, offset, ctx);
+               addr += ctx->size_b;
+       }
+}