/*
* QEMU Crypto cipher algorithms
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "crypto/cipher.h"
#include "cipherpriv.h"
static size_t alg_key_len[QCRYPTO_CIPHER_ALG__MAX] = {
[QCRYPTO_CIPHER_ALG_AES_128] = 16,
[QCRYPTO_CIPHER_ALG_AES_192] = 24,
[QCRYPTO_CIPHER_ALG_AES_256] = 32,
[QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
[QCRYPTO_CIPHER_ALG_3DES] = 24,
[QCRYPTO_CIPHER_ALG_CAST5_128] = 16,
[QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
[QCRYPTO_CIPHER_ALG_SERPENT_192] = 24,
[QCRYPTO_CIPHER_ALG_SERPENT_256] = 32,
[QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
[QCRYPTO_CIPHER_ALG_TWOFISH_192] = 24,
[QCRYPTO_CIPHER_ALG_TWOFISH_256] = 32,
};
static size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = {
[QCRYPTO_CIPHER_ALG_AES_128] = 16,
[QCRYPTO_CIPHER_ALG_AES_192] = 16,
[QCRYPTO_CIPHER_ALG_AES_256] = 16,
[QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
[QCRYPTO_CIPHER_ALG_3DES] = 8,
[QCRYPTO_CIPHER_ALG_CAST5_128] = 8,
[QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
[QCRYPTO_CIPHER_ALG_SERPENT_192] = 16,
[QCRYPTO_CIPHER_ALG_SERPENT_256] = 16,
[QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
[QCRYPTO_CIPHER_ALG_TWOFISH_192] = 16,
[QCRYPTO_CIPHER_ALG_TWOFISH_256] = 16,
};
static bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = {
[QCRYPTO_CIPHER_MODE_ECB] = false,
[QCRYPTO_CIPHER_MODE_CBC] = true,
[QCRYPTO_CIPHER_MODE_XTS] = true,
[QCRYPTO_CIPHER_MODE_CTR] = true,
};
size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg)
{
assert(alg < G_N_ELEMENTS(alg_key_len));
return alg_block_len[alg];
}
size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg)
{
assert(alg < G_N_ELEMENTS(alg_key_len));
return alg_key_len[alg];
}
size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode)
{
if (alg >= G_N_ELEMENTS(alg_block_len)) {
return 0;
}
if (mode >= G_N_ELEMENTS(mode_need_iv)) {
return 0;
}
if (mode_need_iv[mode]) {
return alg_block_len[alg];
}
return 0;
}
static bool
qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode,
size_t nkey,
Error **errp)
{
if ((unsigned)alg >= QCRYPTO_CIPHER_ALG__MAX) {
error_setg(errp, "Cipher algorithm %d out of range",
alg);
return false;
}
if (mode == QCRYPTO_CIPHER_MODE_XTS) {
if (alg == QCRYPTO_CIPHER_ALG_DES_RFB
|| alg == QCRYPTO_CIPHER_ALG_3DES) {
error_setg(errp, "XTS mode not compatible with DES-RFB/3DES");
return false;
}
if (nkey % 2) {
error_setg(errp, "XTS cipher key length should be a multiple of 2");
return false;
}
if (alg_key_len[alg] != (nkey / 2)) {
error_setg(errp, "Cipher key length %zu should be %zu",
nkey, alg_key_len[alg] * 2);
return false;
}
} else {
if (alg_key_len[alg] != nkey) {
error_setg(errp, "Cipher key length %zu should be %zu",
nkey, alg_key_len[alg]);
return false;
}
}
return true;
}
#if defined(CONFIG_GCRYPT) || defined(CONFIG_NETTLE)
static uint8_t *
qcrypto_cipher_munge_des_rfb_key(const uint8_t *key,
size_t nkey)
{
uint8_t *ret = g_new0(uint8_t, nkey);
size_t i;
for (i = 0; i < nkey; i++) {
uint8_t r = key[i];
r = (r & 0xf0) >> 4 | (r & 0x0f) << 4;
r = (r & 0xcc) >> 2 | (r & 0x33) << 2;
r = (r & 0xaa) >> 1 | (r & 0x55) << 1;
ret[i] = r;
}
return ret;
}
#endif /* CONFIG_GCRYPT || CONFIG_NETTLE */
#ifdef CONFIG_GCRYPT
#include "crypto/cipher-gcrypt.c"
#elif defined CONFIG_NETTLE
#include "crypto/cipher-nettle.c"
#else
#include "crypto/cipher-builtin.c"
#endif
QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode,
const uint8_t *key, size_t nkey,
Error **errp)
{
QCryptoCipher *cipher;
void *ctx = NULL;
Error *err2 = NULL;
QCryptoCipherDriver *drv = NULL;
#ifdef CONFIG_AF_ALG
ctx = qcrypto_afalg_cipher_ctx_new(alg, mode, key, nkey, &err2);
if (ctx) {
drv = &qcrypto_cipher_afalg_driver;
}
#endif
if (!ctx) {
ctx = qcrypto_cipher_ctx_new(alg, mode, key, nkey, errp);
if (!ctx) {
error_free(err2);
return NULL;
}
drv = &qcrypto_cipher_lib_driver;
error_free(err2);
}
cipher = g_new0(QCryptoCipher, 1);
cipher->alg = alg;
cipher->mode = mode;
cipher->opaque = ctx;
cipher->driver = (void *)drv;
return cipher;
}
int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherDriver *drv = cipher->driver;
return drv->cipher_encrypt(cipher, in, out, len, errp);
}
int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherDriver *drv = cipher->driver;
return drv->cipher_decrypt(cipher, in, out, len, errp);
}
int qcrypto_cipher_setiv(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
QCryptoCipherDriver *drv = cipher->driver;
return drv->cipher_setiv(cipher, iv, niv, errp);
}
void qcrypto_cipher_free(QCryptoCipher *cipher)
{
QCryptoCipherDriver *drv;
if (cipher) {
drv = cipher->driver;
drv->cipher_free(cipher);
g_free(cipher);
}
}
