Files
GmSSL/src/aes_modes.c
2026-06-14 00:12:10 +08:00

506 lines
11 KiB
C

/*
* Copyright 2014-2026 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 <gmssl/aes.h>
#include <gmssl/mem.h>
#include <gmssl/ghash.h>
#include <gmssl/error.h>
void aes_cbc_encrypt(const AES_KEY *key, const uint8_t iv[16],
const uint8_t *in, size_t nblocks, uint8_t *out)
{
while (nblocks--) {
gmssl_memxor(out, in, iv, 16);
aes_encrypt(key, out, out);
iv = out;
in += 16;
out += 16;
}
}
void aes_cbc_decrypt(const AES_KEY *key, const uint8_t iv[16],
const uint8_t *in, size_t nblocks, uint8_t *out)
{
while (nblocks--) {
aes_decrypt(key, in, out);
memxor(out, iv, 16);
iv = in;
in += 16;
out += 16;
}
}
int aes_cbc_padding_encrypt(const AES_KEY *key, const uint8_t iv[16],
const uint8_t *in, size_t inlen,
uint8_t *out, size_t *outlen)
{
uint8_t block[16];
size_t rem = inlen % 16;
int padding = 16 - inlen % 16;
if (in) {
memcpy(block, in + inlen - rem, rem);
}
memset(block + rem, padding, padding);
if (inlen/16) {
aes_cbc_encrypt(key, iv, in, inlen/16, out);
out += inlen - rem;
iv = out - 16;
}
aes_cbc_encrypt(key, iv, block, 1, out);
*outlen = inlen - rem + 16;
return 1;
}
int aes_cbc_padding_decrypt(const AES_KEY *key, const uint8_t iv[16],
const uint8_t *in, size_t inlen,
uint8_t *out, size_t *outlen)
{
uint8_t block[16];
size_t len = sizeof(block);
int padding;
int i;
if (inlen == 0) {
error_print();
return 0;
}
if (inlen%16 != 0 || inlen < 16) {
error_print();
return -1;
}
if (inlen > 16) {
aes_cbc_decrypt(key, iv, in, inlen/16 - 1, out);
iv = in + inlen - 32;
}
aes_cbc_decrypt(key, iv, in + inlen - 16, 1, block);
padding = block[15];
if (padding < 1 || padding > 16) {
error_print();
return -1;
}
for (i = 16 - padding; i < 16; i++) {
if (block[i] != padding) {
error_print();
return -1;
}
}
len -= padding;
memcpy(out + inlen - 16, block, len);
*outlen = inlen - padding;
return 1;
}
static void ctr_incr(uint8_t a[16])
{
int i;
for (i = 15; i >= 0; i--) {
a[i]++;
if (a[i]) break;
}
}
void aes_ctr_encrypt(const AES_KEY *key, uint8_t ctr[16], const uint8_t *in, size_t inlen, uint8_t *out)
{
uint8_t block[16];
size_t len;
while (inlen) {
len = inlen < 16 ? inlen : 16;
aes_encrypt(key, ctr, block);
gmssl_memxor(out, in, block, len);
ctr_incr(ctr);
in += len;
out += len;
inlen -= len;
}
}
#ifdef ENABLE_AES_CCM
static void length_to_bytes(size_t len, size_t nbytes, uint8_t *out)
{
uint8_t *p = out + nbytes - 1;
while (nbytes--) {
*p-- = len & 0xff;
len >>= 8;
}
}
static void ctr_n_incr(uint8_t a[16], size_t n)
{
size_t i;
for (i = 15; i >= 16 - n; i--) {
a[i]++;
if (a[i]) break;
}
}
static void aes_ctr_n_encrypt(const AES_KEY *key, uint8_t ctr[16], size_t n, const uint8_t *in, size_t inlen, uint8_t *out)
{
uint8_t block[16];
size_t len;
while (inlen) {
len = inlen < 16 ? inlen : 16;
aes_encrypt(key, ctr, block);
gmssl_memxor(out, in, block, len);
ctr_n_incr(ctr, n);
in += len;
out += len;
inlen -= len;
}
}
typedef struct {
AES_KEY key;
uint8_t iv[16];
size_t ivlen;
} AES_CBC_MAC_CTX;
static int aes_cbc_mac_update(AES_CBC_MAC_CTX *ctx, const uint8_t *data, size_t datalen)
{
if (!ctx || (!data && datalen)) {
error_print();
return -1;
}
if (ctx->ivlen >= 16) {
error_print();
return -1;
}
if (!data || !datalen) {
return 1;
}
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) {
aes_encrypt(&ctx->key, ctx->iv, ctx->iv);
ctx->ivlen = 0;
}
data += len;
datalen -= len;
}
return 1;
}
static int aes_cbc_mac_finish(AES_CBC_MAC_CTX *ctx, uint8_t mac[16])
{
if (!ctx || !mac) {
error_print();
return -1;
}
if (ctx->ivlen >= 16) {
error_print();
return -1;
}
if (ctx->ivlen) {
aes_encrypt(&ctx->key, ctx->iv, ctx->iv);
ctx->ivlen = 0;
}
memcpy(mac, ctx->iv, 16);
return 1;
}
int aes_ccm_encrypt(const AES_KEY *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)
{
AES_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 (!key || !iv || (!aad && aadlen) || (!in && inlen) || !out || !tag) {
error_print();
return -1;
}
if (ivlen < 7 || ivlen > 13) {
error_print();
return -1;
}
if (taglen < 4 || taglen > 16 || taglen & 1) {
error_print();
return -1;
}
inlen_size = 15 - ivlen;
if (inlen_size < 8 && inlen >= ((size_t)1 << (inlen_size * 8))) {
error_print();
return -1;
}
memset(&mac_ctx, 0, sizeof(mac_ctx));
mac_ctx.key = *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);
aes_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 ((uint64_t)aadlen < ((uint64_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;
}
aes_cbc_mac_update(&mac_ctx, block, alen);
aes_cbc_mac_update(&mac_ctx, aad, aadlen);
if ((alen + aadlen) % 16) {
aes_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);
aes_encrypt(key, ctr, block);
ctr[15] = 1;
aes_ctr_n_encrypt(key, ctr, 15 - ivlen, in, inlen, out);
aes_cbc_mac_update(&mac_ctx, in, inlen);
if (inlen % 16) {
aes_cbc_mac_update(&mac_ctx, zeros, 16 - inlen % 16);
}
aes_cbc_mac_finish(&mac_ctx, mac);
gmssl_memxor(tag, mac, block, taglen);
gmssl_secure_clear(&mac_ctx, sizeof(mac_ctx));
return 1;
}
int aes_ccm_decrypt(const AES_KEY *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)
{
AES_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 (!key || !iv || (!aad && aadlen) || (!in && inlen) || !tag || !out) {
error_print();
return -1;
}
if (ivlen < 7 || ivlen > 13) {
error_print();
return -1;
}
if (taglen < 4 || taglen > 16 || taglen & 1) {
error_print();
return -1;
}
inlen_size = 15 - ivlen;
if (inlen_size < 8 && inlen >= ((size_t)1 << (inlen_size * 8))) {
error_print();
return -1;
}
memset(&mac_ctx, 0, sizeof(mac_ctx));
mac_ctx.key = *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);
aes_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 ((uint64_t)aadlen < ((uint64_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;
}
aes_cbc_mac_update(&mac_ctx, block, alen);
aes_cbc_mac_update(&mac_ctx, aad, aadlen);
if ((alen + aadlen) % 16) {
aes_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);
aes_encrypt(key, ctr, block);
ctr[15] = 1;
aes_ctr_n_encrypt(key, ctr, 15 - ivlen, in, inlen, out);
aes_cbc_mac_update(&mac_ctx, out, inlen);
if (inlen % 16) {
aes_cbc_mac_update(&mac_ctx, zeros, 16 - inlen % 16);
}
aes_cbc_mac_finish(&mac_ctx, mac);
gmssl_memxor(mac, mac, block, taglen);
if (gmssl_secure_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;
}
#endif
static void ctr32_incr(uint8_t a[16])
{
int i;
for (i = 15; i >= 12; i--) {
a[i]++;
if (a[i]) break;
}
}
static void aes_ctr32_encrypt(const AES_KEY *key, uint8_t ctr[16], const uint8_t *in, size_t inlen, uint8_t *out)
{
uint8_t block[16];
size_t len;
while (inlen) {
len = inlen < 16 ? inlen : 16;
aes_encrypt(key, ctr, block);
gmssl_memxor(out, in, block, len);
ctr32_incr(ctr);
in += len;
out += len;
inlen -= len;
}
gmssl_secure_clear(block, sizeof(block));
}
int aes_gcm_encrypt(const AES_KEY *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)
{
const uint8_t *pin = in;
uint8_t *pout = out;
size_t left = inlen;
uint8_t H[16] = {0};
uint8_t Y[16];
uint8_t T[16];
if (taglen > AES_GCM_MAX_TAG_SIZE) {
error_print();
return -1;
}
aes_encrypt(key, H, H);
if (ivlen == 12) {
memcpy(Y, iv, 12);
Y[12] = Y[13] = Y[14] = 0;
Y[15] = 1;
} else {
ghash(H, NULL, 0, iv, ivlen, Y);
}
aes_encrypt(key, Y, T);
ctr32_incr(Y);
aes_ctr32_encrypt(key, Y, in, inlen, out);
ghash(H, aad, aadlen, out, inlen, H);
gmssl_memxor(tag, T, H, taglen);
gmssl_secure_clear(H, sizeof(H));
gmssl_secure_clear(Y, sizeof(Y));
gmssl_secure_clear(T, sizeof(T));
return 1;
}
int aes_gcm_decrypt(const AES_KEY *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)
{
const uint8_t *pin = in;
uint8_t *pout = out;
size_t left = inlen;
uint8_t H[16] = {0};
uint8_t Y[16];
uint8_t T[16];
if (taglen > AES_GCM_MAX_TAG_SIZE) {
error_print();
return -1;
}
aes_encrypt(key, H, H);
if (ivlen == 12) {
memcpy(Y, iv, 12);
Y[12] = Y[13] = Y[14] = 0;
Y[15] = 1;
} else {
ghash(H, NULL, 0, iv, ivlen, Y);
}
ghash(H, aad, aadlen, in, inlen, H);
aes_encrypt(key, Y, T);
gmssl_memxor(T, T, H, taglen);
if (gmssl_secure_memcmp(T, tag, taglen) != 0) {
gmssl_secure_clear(H, sizeof(H));
gmssl_secure_clear(Y, sizeof(Y));
gmssl_secure_clear(T, sizeof(T));
error_print();
return -1;
}
ctr32_incr(Y);
aes_ctr32_encrypt(key, Y, in, inlen, out);
gmssl_secure_clear(H, sizeof(H));
gmssl_secure_clear(Y, sizeof(Y));
gmssl_secure_clear(T, sizeof(T));
return 1;
}