gateway2/Tongsuo-8.4.0/crypto/eia3/eia3.c
2026-07-11 13:40:57 +08:00

128 lines
3.2 KiB
C

/*
* Copyright 2023 The Tongsuo Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://github.com/Tongsuo-Project/Tongsuo/blob/master/LICENSE.txt
*/
#include <stdlib.h>
#include <string.h>
#include <openssl/crypto.h>
#ifndef OPENSSL_NO_ZUC
# include "crypto/zuc.h"
# include "eia3_local.h"
static ossl_inline uint8_t GET_BIT(const unsigned char *data, uint32_t i)
{
return (data[i / 8] & (1 << (7 - (i % 8)))) ? 1 : 0;
}
size_t EIA3_ctx_size(void)
{
return sizeof(struct eia3_context);
}
int EIA3_Init(EIA3_CTX *ctx, const unsigned char key[EVP_ZUC_KEY_SIZE], const unsigned char iv[5])
{
ZUC_KEY *zk = &ctx->zk;
uint32_t count = 0;
uint32_t bearer = 0;
uint32_t direction = 0;
memset(ctx, 0, sizeof(EIA3_CTX));
zk->k = key;
/*
* This is a lazy approach: we 'borrow' the 'iv' parameter
* to use it as a place of transfer the EEA3 iv params -
* count, bearer and direction.
*
* count is 32 bits, bearer is 5 bits and direction is 1
* bit so we read the first 38 bits of iv. And the whole
* iv is set to 5 bytes (40 bits).
*/
if (iv != NULL) {
count = ((long)iv[0] << 24) | (iv[1] << 16) | (iv[2] << 8) | iv[3];
bearer = (iv[4] & 0xF8) >> 3;
direction = (iv[4] & 0x4) >> 2;
}
zk->iv[0] = (count >> 24) & 0xFF;
zk->iv[1] = (count >> 16) & 0xFF;
zk->iv[2] = (count >> 8) & 0xFF;
zk->iv[3] = count & 0xFF;
zk->iv[4] = (bearer << 3) & 0xF8;
zk->iv[5] = zk->iv[6] = zk->iv[7] = 0;
zk->iv[8] = ((count >> 24) & 0xFF) ^ ((direction & 1) << 7);
zk->iv[9] = (count >> 16) & 0xFF;
zk->iv[10] = (count >> 8) & 0xFF;
zk->iv[11] = count & 0xFF;
zk->iv[12] = zk->iv[4];
zk->iv[13] = zk->iv[5];
zk->iv[14] = zk->iv[6] ^ ((direction & 1) << 7);
zk->iv[15] = zk->iv[7];
ZUC_init(zk);
return 1;
}
int EIA3_Update(EIA3_CTX *ctx, const unsigned char *inp, size_t len)
{
ZUC_KEY *zk = &ctx->zk;
size_t i, length = len * 8;
for (i = 0; i < length; i++) {
if ((ctx->num + i/8 + 4) >= zk->keystream_len) {
if (!ZUC_generate_keystream(zk))
return 0;
}
if (GET_BIT(inp, i))
ctx->T ^= ZUC_keystream_get_word(zk, i);
}
ctx->length += length;
ctx->num += len;
return 1;
}
void EIA3_Final(EIA3_CTX *ctx, unsigned char out[EIA3_DIGEST_SIZE])
{
ZUC_KEY *zk = &ctx->zk;
size_t L = (ctx->length + 64 + 31) / 32, last;
uint32_t mac;
if ((ctx->length / 8 + 4) >= zk->keystream_len) {
if (!ZUC_generate_keystream(zk))
return;
}
ctx->T ^= ZUC_keystream_get_word(zk, ctx->length);
last = (L - 1) * 32;
if ((last / 8 + 4) >= zk->keystream_len) {
if (!ZUC_generate_keystream(zk))
return;
}
mac = ctx->T ^ ZUC_keystream_get_word(zk, (L - 1) * 32);
out[0] = (uint8_t)(mac >> 24) & 0xFF;
out[1] = (uint8_t)(mac >> 16) & 0xFF;
out[2] = (uint8_t)(mac >> 8) & 0xFF;
out[3] = (uint8_t)mac & 0xFF;
ZUC_destroy_keystream(&ctx->zk);
}
#endif