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Add more SM4 modes

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This commit is contained in:
Zhi Guan
2024-02-19 14:16:49 +08:00
parent 8ae03e8105
commit c9c26aca44
12 changed files with 1092 additions and 61 deletions
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147
src/sm4_ccm.c
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@@ -14,10 +14,6 @@
#include <gmssl/error.h>
#define SM4_CCM_MIN_IV_SIZE 7
#define SM4_CCM_MAX_IV_SIZE 13
#define SM4_CCM_MIN_MAC_SIZE 4
#define SM4_CCM_MAX_MAC_SIZE 16
static void length_to_bytes(size_t len, size_t nbytes, uint8_t *out)
@@ -29,18 +25,16 @@ static void length_to_bytes(size_t len, size_t nbytes, uint8_t *out)
}
}
int sm4_ccm_encrypt(SM4_KEY *sm4_key, const uint8_t *iv, size_t ivlen,
int sm4_ccm_encrypt(const SM4_KEY *sm4_key, const uint8_t *iv, size_t ivlen,
const uint8_t *aad, size_t aadlen, const uint8_t *in, size_t inlen,
uint8_t *out, size_t taglen, uint8_t *tag)
{
SM4_CBC_MAC_CTX cbc_mac_ctx;
size_t inlen_size;
SM4_CBC_MAC_CTX mac_ctx;
const uint8_t zeros[16] = {0};
uint8_t block[16] = {0};
uint8_t ctr[16] = {0};
uint8_t S0[16];
uint8_t cbc_mac[16];
const uint8_t zeros[16] = {0};
size_t padding_len;
uint8_t mac[16];
size_t inlen_size;
if (ivlen < 7 || ivlen > 13) {
error_print();
@@ -56,22 +50,21 @@ int sm4_ccm_encrypt(SM4_KEY *sm4_key, const uint8_t *iv, size_t ivlen,
}
inlen_size = 15 - ivlen;
if (inlen >= (1 << (inlen_size * 8))) {
if (inlen_size < 8 && inlen >= (1 << (inlen_size * 8))) {
error_print();
return -1;
}
// sm4_cbc_mac_init
memset(&cbc_mac_ctx, 0, sizeof(cbc_mac_ctx));
cbc_mac_ctx.key = *sm4_key;
// sm4_cbc_mac_init with SM4_KEY
memset(&mac_ctx, 0, sizeof(mac_ctx));
mac_ctx.key = *sm4_key;
// first block
block[0] |= ((aadlen > 0) & 0x1) << 6;
block[0] |= (((taglen - 2)/2) & 0x7) << 3;
block[0] |= (inlen_size - 1) & 0x7;
memcpy(block + 1, iv, ivlen);
length_to_bytes(inlen, inlen_size, block + 1 + ivlen);
sm4_cbc_mac_update(&cbc_mac_ctx, block, 16);
sm4_cbc_mac_update(&mac_ctx, block, 16);
if (aad && aadlen) {
size_t alen;
@@ -88,35 +81,123 @@ int sm4_ccm_encrypt(SM4_KEY *sm4_key, const uint8_t *iv, size_t ivlen,
block[0] = 0xff;
block[1] = 0xff;
length_to_bytes(aadlen, 8, block + 2);
alen = 10;
}
sm4_cbc_mac_update(&cbc_mac_ctx, block, alen);
sm4_cbc_mac_update(&cbc_mac_ctx, aad, aadlen);
sm4_cbc_mac_update(&mac_ctx, block, alen);
sm4_cbc_mac_update(&mac_ctx, aad, aadlen);
if (alen + aadlen % 16) {
sm4_cbc_mac_update(&cbc_mac_ctx, zeros, 16 - (alen + aadlen)%16);
sm4_cbc_mac_update(&mac_ctx, zeros, 16 - (alen + aadlen)%16);
}
}
sm4_cbc_mac_update(&cbc_mac_ctx, in, inlen);
if (inlen % 16) {
sm4_cbc_mac_update(&cbc_mac_ctx, zeros, 16 - inlen%16);
}
sm4_cbc_mac_finish(&cbc_mac_ctx, cbc_mac);
ctr[0] = 0;
ctr[0] |= (inlen_size - 1) & 0x7;
memcpy(ctr + 1, iv, ivlen);
memset(ctr + 1 + ivlen, 0, 15 - ivlen);
sm4_encrypt(sm4_key, ctr, S0);
gmssl_memxor(out, cbc_mac, S0, taglen);
sm4_encrypt(sm4_key, ctr, block);
ctr[15] = 1;
sm4_ctr_encrypt(sm4_key, ctr, in, inlen, out);
gmssl_secure_clear(&cbc_mac_ctx, sizeof(cbc_mac_ctx));
sm4_cbc_mac_update(&mac_ctx, in, inlen);
if (inlen % 16) {
sm4_cbc_mac_update(&mac_ctx, zeros, 16 - inlen % 16);
}
sm4_cbc_mac_finish(&mac_ctx, mac);
gmssl_memxor(tag, mac, block, taglen);
gmssl_secure_clear(&mac_ctx, sizeof(mac_ctx));
return 1;
}
int sm4_ccm_decrypt(const SM4_KEY *sm4_key, const uint8_t *iv, size_t ivlen,
const uint8_t *aad, size_t aadlen, const uint8_t *in, size_t inlen,
const uint8_t *tag, size_t taglen, uint8_t *out)
{
SM4_CBC_MAC_CTX mac_ctx;
const uint8_t zeros[16] = {0};
uint8_t block[16] = {0};
uint8_t ctr[16] = {0};
uint8_t mac[16];
size_t inlen_size;
if (ivlen < 7 || ivlen > 13) {
error_print();
return -1;
}
if (!aad && aadlen) {
error_print();
return -1;
}
if (taglen < 4 || taglen > 16 || taglen & 1) {
error_print();
return -1;
}
inlen_size = 15 - ivlen;
if (inlen_size < 8 && inlen >= (1 << (inlen_size * 8))) {
error_print();
return -1;
}
// sm4_cbc_mac_init with SM4_KEY
memset(&mac_ctx, 0, sizeof(mac_ctx));
mac_ctx.key = *sm4_key;
block[0] |= ((aadlen > 0) & 0x1) << 6;
block[0] |= (((taglen - 2)/2) & 0x7) << 3;
block[0] |= (inlen_size - 1) & 0x7;
memcpy(block + 1, iv, ivlen);
length_to_bytes(inlen, inlen_size, block + 1 + ivlen);
sm4_cbc_mac_update(&mac_ctx, block, 16);
if (aad && aadlen) {
size_t alen;
if (aadlen < ((1<<16) - (1<<8))) {
length_to_bytes(aadlen, 2, block);
alen = 2;
} else if (aadlen < ((size_t)1<<32)) {
block[0] = 0xff;
block[1] = 0xfe;
length_to_bytes(aadlen, 4, block + 2);
alen = 6;
} else {
block[0] = 0xff;
block[1] = 0xff;
length_to_bytes(aadlen, 8, block + 2);
alen = 10;
}
sm4_cbc_mac_update(&mac_ctx, block, alen);
sm4_cbc_mac_update(&mac_ctx, aad, aadlen);
if (alen + aadlen % 16) {
sm4_cbc_mac_update(&mac_ctx, zeros, 16 - (alen + aadlen)%16);
}
}
ctr[0] = 0;
ctr[0] |= (inlen_size - 1) & 0x7;
memcpy(ctr + 1, iv, ivlen);
memset(ctr + 1 + ivlen, 0, 15 - ivlen);
sm4_encrypt(sm4_key, ctr, block);
ctr[15] = 1;
sm4_ctr_encrypt(sm4_key, ctr, in, inlen, out);
sm4_cbc_mac_update(&mac_ctx, out, inlen); // diff from encrypt
if (inlen % 16) {
sm4_cbc_mac_update(&mac_ctx, zeros, 16 - inlen % 16);
}
sm4_cbc_mac_finish(&mac_ctx, mac);
// diff from encrypt
gmssl_memxor(mac, mac, block, taglen);
if (memcmp(mac, tag, taglen) != 0) {
error_print();
gmssl_secure_clear(&mac_ctx, sizeof(mac_ctx));
return -1;
}
gmssl_secure_clear(&mac_ctx, sizeof(mac_ctx));
return 1;
}