X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=bcal-eax.c;fp=bcal-eax.c;h=72d68bd2ed354145c6c45a5f0257934390180394;hb=3f2f2071c47e2e424af71cc85697f3eb26c24277;hp=0000000000000000000000000000000000000000;hpb=33a28395461ecd0c1c7820f59e180f8f2ca9216f;p=arm-crypto-lib.git

diff --git a/bcal-eax.c b/bcal-eax.c
new file mode 100644
index 0000000..72d68bd
--- /dev/null
+++ b/bcal-eax.c
@@ -0,0 +1,119 @@
+/* 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);
+}
+