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/*
* QEMU Crypto cipher libgcrypt 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 2.1 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 <gcrypt.h>
static int qcrypto_cipher_alg_to_gcry_alg(QCryptoCipherAlgorithm alg)
{
switch (alg) {
case QCRYPTO_CIPHER_ALG_DES:
return GCRY_CIPHER_DES;
case QCRYPTO_CIPHER_ALG_3DES:
return GCRY_CIPHER_3DES;
case QCRYPTO_CIPHER_ALG_AES_128:
return GCRY_CIPHER_AES128;
case QCRYPTO_CIPHER_ALG_AES_192:
return GCRY_CIPHER_AES192;
case QCRYPTO_CIPHER_ALG_AES_256:
return GCRY_CIPHER_AES256;
case QCRYPTO_CIPHER_ALG_CAST5_128:
return GCRY_CIPHER_CAST5;
case QCRYPTO_CIPHER_ALG_SERPENT_128:
return GCRY_CIPHER_SERPENT128;
case QCRYPTO_CIPHER_ALG_SERPENT_192:
return GCRY_CIPHER_SERPENT192;
case QCRYPTO_CIPHER_ALG_SERPENT_256:
return GCRY_CIPHER_SERPENT256;
case QCRYPTO_CIPHER_ALG_TWOFISH_128:
return GCRY_CIPHER_TWOFISH128;
case QCRYPTO_CIPHER_ALG_TWOFISH_256:
return GCRY_CIPHER_TWOFISH;
#ifdef CONFIG_CRYPTO_SM4
case QCRYPTO_CIPHER_ALG_SM4:
return GCRY_CIPHER_SM4;
#endif
default:
return GCRY_CIPHER_NONE;
}
}
static int qcrypto_cipher_mode_to_gcry_mode(QCryptoCipherMode mode)
{
switch (mode) {
case QCRYPTO_CIPHER_MODE_ECB:
return GCRY_CIPHER_MODE_ECB;
case QCRYPTO_CIPHER_MODE_XTS:
return GCRY_CIPHER_MODE_XTS;
case QCRYPTO_CIPHER_MODE_CBC:
return GCRY_CIPHER_MODE_CBC;
case QCRYPTO_CIPHER_MODE_CTR:
return GCRY_CIPHER_MODE_CTR;
default:
return GCRY_CIPHER_MODE_NONE;
}
}
bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode)
{
switch (alg) {
case QCRYPTO_CIPHER_ALG_DES:
case QCRYPTO_CIPHER_ALG_3DES:
case QCRYPTO_CIPHER_ALG_AES_128:
case QCRYPTO_CIPHER_ALG_AES_192:
case QCRYPTO_CIPHER_ALG_AES_256:
case QCRYPTO_CIPHER_ALG_CAST5_128:
case QCRYPTO_CIPHER_ALG_SERPENT_128:
case QCRYPTO_CIPHER_ALG_SERPENT_192:
case QCRYPTO_CIPHER_ALG_SERPENT_256:
case QCRYPTO_CIPHER_ALG_TWOFISH_128:
case QCRYPTO_CIPHER_ALG_TWOFISH_256:
#ifdef CONFIG_CRYPTO_SM4
case QCRYPTO_CIPHER_ALG_SM4:
#endif
break;
default:
return false;
}
if (gcry_cipher_algo_info(qcrypto_cipher_alg_to_gcry_alg(alg),
GCRYCTL_TEST_ALGO, NULL, NULL) != 0) {
return false;
}
switch (mode) {
case QCRYPTO_CIPHER_MODE_ECB:
case QCRYPTO_CIPHER_MODE_CBC:
case QCRYPTO_CIPHER_MODE_XTS:
case QCRYPTO_CIPHER_MODE_CTR:
return true;
default:
return false;
}
}
typedef struct QCryptoCipherGcrypt {
QCryptoCipher base;
gcry_cipher_hd_t handle;
size_t blocksize;
} QCryptoCipherGcrypt;
static void qcrypto_gcrypt_ctx_free(QCryptoCipher *cipher)
{
QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
gcry_cipher_close(ctx->handle);
g_free(ctx);
}
static int qcrypto_gcrypt_encrypt(QCryptoCipher *cipher, const void *in,
void *out, size_t len, Error **errp)
{
QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
gcry_error_t err;
if (len & (ctx->blocksize - 1)) {
error_setg(errp, "Length %zu must be a multiple of block size %zu",
len, ctx->blocksize);
return -1;
}
err = gcry_cipher_encrypt(ctx->handle, out, len, in, len);
if (err != 0) {
error_setg(errp, "Cannot encrypt data: %s", gcry_strerror(err));
return -1;
}
return 0;
}
static int qcrypto_gcrypt_decrypt(QCryptoCipher *cipher, const void *in,
void *out, size_t len, Error **errp)
{
QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
gcry_error_t err;
if (len & (ctx->blocksize - 1)) {
error_setg(errp, "Length %zu must be a multiple of block size %zu",
len, ctx->blocksize);
return -1;
}
err = gcry_cipher_decrypt(ctx->handle, out, len, in, len);
if (err != 0) {
error_setg(errp, "Cannot decrypt data: %s",
gcry_strerror(err));
return -1;
}
return 0;
}
static int qcrypto_gcrypt_setiv(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
gcry_error_t err;
if (niv != ctx->blocksize) {
error_setg(errp, "Expected IV size %zu not %zu",
ctx->blocksize, niv);
return -1;
}
gcry_cipher_reset(ctx->handle);
err = gcry_cipher_setiv(ctx->handle, iv, niv);
if (err != 0) {
error_setg(errp, "Cannot set IV: %s", gcry_strerror(err));
return -1;
}
return 0;
}
static int qcrypto_gcrypt_ctr_setiv(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
gcry_error_t err;
if (niv != ctx->blocksize) {
error_setg(errp, "Expected IV size %zu not %zu",
ctx->blocksize, niv);
return -1;
}
err = gcry_cipher_setctr(ctx->handle, iv, niv);
if (err != 0) {
error_setg(errp, "Cannot set Counter: %s", gcry_strerror(err));
return -1;
}
return 0;
}
static const struct QCryptoCipherDriver qcrypto_gcrypt_driver = {
.cipher_encrypt = qcrypto_gcrypt_encrypt,
.cipher_decrypt = qcrypto_gcrypt_decrypt,
.cipher_setiv = qcrypto_gcrypt_setiv,
.cipher_free = qcrypto_gcrypt_ctx_free,
};
static const struct QCryptoCipherDriver qcrypto_gcrypt_ctr_driver = {
.cipher_encrypt = qcrypto_gcrypt_encrypt,
.cipher_decrypt = qcrypto_gcrypt_decrypt,
.cipher_setiv = qcrypto_gcrypt_ctr_setiv,
.cipher_free = qcrypto_gcrypt_ctx_free,
};
static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode,
const uint8_t *key,
size_t nkey,
Error **errp)
{
QCryptoCipherGcrypt *ctx;
const QCryptoCipherDriver *drv;
gcry_error_t err;
int gcryalg, gcrymode;
if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
return NULL;
}
gcryalg = qcrypto_cipher_alg_to_gcry_alg(alg);
if (gcryalg == GCRY_CIPHER_NONE) {
error_setg(errp, "Unsupported cipher algorithm %s",
QCryptoCipherAlgorithm_str(alg));
return NULL;
}
gcrymode = qcrypto_cipher_mode_to_gcry_mode(mode);
if (gcrymode == GCRY_CIPHER_MODE_NONE) {
error_setg(errp, "Unsupported cipher mode %s",
QCryptoCipherMode_str(mode));
return NULL;
}
if (mode == QCRYPTO_CIPHER_MODE_CTR) {
drv = &qcrypto_gcrypt_ctr_driver;
} else {
drv = &qcrypto_gcrypt_driver;
}
ctx = g_new0(QCryptoCipherGcrypt, 1);
ctx->base.driver = drv;
err = gcry_cipher_open(&ctx->handle, gcryalg, gcrymode, 0);
if (err != 0) {
error_setg(errp, "Cannot initialize cipher: %s",
gcry_strerror(err));
goto error;
}
ctx->blocksize = gcry_cipher_get_algo_blklen(gcryalg);
err = gcry_cipher_setkey(ctx->handle, key, nkey);
if (err != 0) {
error_setg(errp, "Cannot set key: %s", gcry_strerror(err));
goto error;
}
return &ctx->base;
error:
gcry_cipher_close(ctx->handle);
g_free(ctx);
return NULL;
}