120 lines
3.6 KiB
C
120 lines
3.6 KiB
C
/* bca-eax.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 "bcal-basic.h"
|
|
#include "blockcipher_descriptor.h"
|
|
#include "bcal-cmac.h"
|
|
#include "bcal-ctr.h"
|
|
#include "bcal-eax.h"
|
|
#include "memxor.h"
|
|
|
|
uint8_t bcal_eax_init(const bcdesc_t* desc, const void* key, uint16_t keysize_b, bcal_eax_ctx_t* ctx){
|
|
uint8_t r;
|
|
ctx->blocksize_B = (bcal_cipher_getBlocksize_b(desc)+7)/8;
|
|
ctx->nonce = malloc(ctx->blocksize_B);
|
|
if(ctx->nonce==NULL){
|
|
return 0x81;
|
|
}
|
|
r = bcal_cmac_init(desc, key, keysize_b, &(ctx->ctag));
|
|
if(r){
|
|
return r;
|
|
}
|
|
r = bcal_cmac_init(desc, key, keysize_b, &(ctx->htag));
|
|
if(r){
|
|
return (r|0x10);
|
|
}
|
|
r = bcal_cmac_init(desc, key, keysize_b, &(ctx->ntag));
|
|
if(r){
|
|
return (r|0x20);
|
|
}
|
|
r = bcal_ctr_init(desc, key, keysize_b, NULL, &(ctx->cipher));
|
|
if(r){
|
|
return (r|0x30);
|
|
}
|
|
ctx->header_set=0;
|
|
uint8_t tmp[ctx->blocksize_B];
|
|
memset(tmp, 0, ctx->blocksize_B);
|
|
bcal_cmac_nextBlock(&(ctx->ntag), tmp);
|
|
tmp[ctx->blocksize_B-1]=1;
|
|
bcal_cmac_nextBlock(&(ctx->htag), tmp);
|
|
tmp[ctx->blocksize_B-1]=2;
|
|
bcal_cmac_nextBlock(&(ctx->ctag), tmp);
|
|
return 0;
|
|
}
|
|
|
|
void bcal_eax_free(bcal_eax_ctx_t* ctx){
|
|
bcal_ctr_free(&(ctx->cipher));
|
|
bcal_cmac_free(&(ctx->ctag));
|
|
bcal_cmac_free(&(ctx->htag));
|
|
bcal_cmac_free(&(ctx->ntag));
|
|
free(ctx->nonce);
|
|
}
|
|
|
|
void bcal_eax_loadNonce(const void* nonce, uint16_t length_b, bcal_eax_ctx_t* ctx){
|
|
bcal_cmac_lastBlock(&(ctx->ntag), nonce, length_b);
|
|
bcal_cmac_ctx2mac(ctx->nonce, ctx->blocksize_B*8, &(ctx->ntag));
|
|
bcal_ctr_loadIV(ctx->nonce, &(ctx->cipher));
|
|
}
|
|
|
|
void bcal_eax_addNextHeader(const void* header, bcal_eax_ctx_t* ctx){
|
|
bcal_cmac_nextBlock(&(ctx->htag), header);
|
|
}
|
|
|
|
void bcal_eax_addLastHeader(const void* header, uint16_t length_b, bcal_eax_ctx_t* ctx){
|
|
bcal_cmac_lastBlock(&(ctx->htag), header, length_b);
|
|
ctx->header_set = 1;
|
|
}
|
|
|
|
void bcal_eax_encNextBlock(void* block, bcal_eax_ctx_t* ctx){
|
|
bcal_ctr_encNext(block, &(ctx->cipher));
|
|
bcal_cmac_nextBlock(&(ctx->ctag), block);
|
|
}
|
|
|
|
void bcal_eax_encLastBlock(void* block, uint16_t length_b, bcal_eax_ctx_t* ctx){
|
|
bcal_ctr_encMsg(NULL, block, length_b, &(ctx->cipher));
|
|
bcal_cmac_lastBlock(&(ctx->ctag), block, length_b);
|
|
}
|
|
|
|
void bcal_eax_decNextBlock(void* block, bcal_eax_ctx_t* ctx){
|
|
bcal_cmac_nextBlock(&(ctx->ctag), block);
|
|
bcal_ctr_decNext(block, &(ctx->cipher));
|
|
}
|
|
|
|
void bcal_eax_decLastBlock(void* block, uint16_t length_b, bcal_eax_ctx_t* ctx){
|
|
bcal_cmac_lastBlock(&(ctx->ctag), block, length_b);
|
|
bcal_ctr_decMsg(NULL, block, length_b, &(ctx->cipher));
|
|
}
|
|
|
|
void bcal_eax_ctx2tag(void* dest, uint16_t length_b, bcal_eax_ctx_t* ctx){
|
|
uint8_t tmp[ctx->blocksize_B];
|
|
if(ctx->header_set==0){
|
|
bcal_cmac_lastBlock(&(ctx->htag), NULL, 0);
|
|
}
|
|
|
|
bcal_cmac_ctx2mac(tmp, ctx->blocksize_B*8, &(ctx->htag));
|
|
memxor(ctx->nonce, tmp, ctx->blocksize_B);
|
|
|
|
bcal_cmac_ctx2mac(tmp, ctx->blocksize_B*8, &(ctx->ctag));
|
|
memxor(ctx->nonce, tmp, ctx->blocksize_B);
|
|
memcpy(dest, ctx->nonce, (length_b+7)/8);
|
|
}
|
|
|