Files
GmSSL/src/sm4_cbc_mac.c
2022-12-30 14:53:20 +08:00

50 lines
1.1 KiB
C

/*
* Copyright 2014-2022 The GmSSL Project. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
*
* http://www.apache.org/licenses/LICENSE-2.0
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <gmssl/mem.h>
#include <gmssl/rand.h>
#include <gmssl/error.h>
#include <gmssl/sm4_cbc_mac.h>
void sm4_cbc_mac_init(SM4_CBC_MAC_CTX *ctx, const uint8_t key[16])
{
sm4_set_encrypt_key(&ctx->key, key);
memset(ctx->iv, 0, 16);
ctx->ivlen = 0;
}
void sm4_cbc_mac_update(SM4_CBC_MAC_CTX *ctx, const uint8_t *data, size_t datalen)
{
while (datalen) {
size_t ivleft = 16 - ctx->ivlen;
size_t len = datalen < ivleft ? datalen : ivleft;
gmssl_memxor(ctx->iv + ctx->ivlen, ctx->iv + ctx->ivlen, data, len);
ctx->ivlen += len;
if (ctx->ivlen >= 16) {
sm4_encrypt(&ctx->key, ctx->iv, ctx->iv);
ctx->ivlen = 0;
}
data += len;
datalen -= len;
}
}
void sm4_cbc_mac_finish(SM4_CBC_MAC_CTX *ctx, uint8_t mac[16])
{
if (ctx->ivlen) {
sm4_encrypt(&ctx->key, ctx->iv, ctx->iv);
}
memcpy(mac, ctx->iv, 16);
}