qemu/crypto/cipher-gcrypt.c

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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 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>
bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg)
{
switch (alg) {
case QCRYPTO_CIPHER_ALG_DES_RFB:
case QCRYPTO_CIPHER_ALG_AES_128:
case QCRYPTO_CIPHER_ALG_AES_192:
case QCRYPTO_CIPHER_ALG_AES_256:
return true;
default:
return false;
}
}
QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode,
const uint8_t *key, size_t nkey,
Error **errp)
{
QCryptoCipher *cipher;
gcry_cipher_hd_t handle;
gcry_error_t err;
int gcryalg, gcrymode;
switch (mode) {
case QCRYPTO_CIPHER_MODE_ECB:
gcrymode = GCRY_CIPHER_MODE_ECB;
break;
case QCRYPTO_CIPHER_MODE_CBC:
gcrymode = GCRY_CIPHER_MODE_CBC;
break;
default:
error_setg(errp, "Unsupported cipher mode %d", mode);
return NULL;
}
if (!qcrypto_cipher_validate_key_length(alg, nkey, errp)) {
return NULL;
}
switch (alg) {
case QCRYPTO_CIPHER_ALG_DES_RFB:
gcryalg = GCRY_CIPHER_DES;
break;
case QCRYPTO_CIPHER_ALG_AES_128:
gcryalg = GCRY_CIPHER_AES128;
break;
case QCRYPTO_CIPHER_ALG_AES_192:
gcryalg = GCRY_CIPHER_AES192;
break;
case QCRYPTO_CIPHER_ALG_AES_256:
gcryalg = GCRY_CIPHER_AES256;
break;
default:
error_setg(errp, "Unsupported cipher algorithm %d", alg);
return NULL;
}
cipher = g_new0(QCryptoCipher, 1);
cipher->alg = alg;
cipher->mode = mode;
err = gcry_cipher_open(&handle, gcryalg, gcrymode, 0);
if (err != 0) {
error_setg(errp, "Cannot initialize cipher: %s",
gcry_strerror(err));
goto error;
}
if (cipher->alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
/* We're using standard DES cipher from gcrypt, so we need
* to munge the key so that the results are the same as the
* bizarre RFB variant of DES :-)
*/
uint8_t *rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
err = gcry_cipher_setkey(handle, rfbkey, nkey);
g_free(rfbkey);
} else {
err = gcry_cipher_setkey(handle, key, nkey);
}
if (err != 0) {
error_setg(errp, "Cannot set key: %s",
gcry_strerror(err));
goto error;
}
cipher->opaque = handle;
return cipher;
error:
gcry_cipher_close(handle);
g_free(cipher);
return NULL;
}
void qcrypto_cipher_free(QCryptoCipher *cipher)
{
gcry_cipher_hd_t handle;
if (!cipher) {
return;
}
handle = cipher->opaque;
gcry_cipher_close(handle);
g_free(cipher);
}
int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
gcry_cipher_hd_t handle = cipher->opaque;
gcry_error_t err;
err = gcry_cipher_encrypt(handle,
out, len,
in, len);
if (err != 0) {
error_setg(errp, "Cannot encrypt data: %s",
gcry_strerror(err));
return -1;
}
return 0;
}
int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
gcry_cipher_hd_t handle = cipher->opaque;
gcry_error_t err;
err = gcry_cipher_decrypt(handle,
out, len,
in, len);
if (err != 0) {
error_setg(errp, "Cannot decrypt data: %s",
gcry_strerror(err));
return -1;
}
return 0;
}
int qcrypto_cipher_setiv(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
gcry_cipher_hd_t handle = cipher->opaque;
gcry_error_t err;
gcry_cipher_reset(handle);
err = gcry_cipher_setiv(handle, iv, niv);
if (err != 0) {
error_setg(errp, "Cannot set IV: %s",
gcry_strerror(err));
return -1;
}
return 0;
}