forgotten directories

[avr-crypto-lib.git] / bcal / bcal-eax.c

diff --git a/bcal/bcal-eax.c b/bcal/bcal-eax.c
new file mode 100644 (file)
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+++ b/bcal/bcal-eax.c
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+/* bca-eax.c */
+/*
+    This file is part of the AVR-Crypto-Lib.
+    Copyright (C) 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/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);
+}
+