/*
* QEMU Crypto cipher nettle 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 "crypto/xts.h"
#include "cipherpriv.h"
#include <nettle/nettle-types.h>
#include <nettle/aes.h>
#include <nettle/des.h>
#include <nettle/cbc.h>
#include <nettle/cast128.h>
#include <nettle/serpent.h>
#include <nettle/twofish.h>
#include <nettle/ctr.h>
typedef void (*QCryptoCipherNettleFuncWrapper)(const void *ctx,
size_t length,
uint8_t *dst,
const uint8_t *src);
#if CONFIG_NETTLE_VERSION_MAJOR < 3
typedef nettle_crypt_func * QCryptoCipherNettleFuncNative;
typedef void * cipher_ctx_t;
typedef unsigned cipher_length_t;
#define cast5_set_key cast128_set_key
#else
typedef nettle_cipher_func * QCryptoCipherNettleFuncNative;
typedef const void * cipher_ctx_t;
typedef size_t cipher_length_t;
#endif
typedef struct QCryptoNettleAES {
struct aes_ctx enc;
struct aes_ctx dec;
} QCryptoNettleAES;
static void aes_encrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
const QCryptoNettleAES *aesctx = ctx;
aes_encrypt(&aesctx->enc, length, dst, src);
}
static void aes_decrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
const QCryptoNettleAES *aesctx = ctx;
aes_decrypt(&aesctx->dec, length, dst, src);
}
static void des_encrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
des_encrypt(ctx, length, dst, src);
}
static void des_decrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
des_decrypt(ctx, length, dst, src);
}
static void des3_encrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
des3_encrypt(ctx, length, dst, src);
}
static void des3_decrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
des3_decrypt(ctx, length, dst, src);
}
static void cast128_encrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
cast128_encrypt(ctx, length, dst, src);
}
static void cast128_decrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
cast128_decrypt(ctx, length, dst, src);
}
static void serpent_encrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
serpent_encrypt(ctx, length, dst, src);
}
static void serpent_decrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
serpent_decrypt(ctx, length, dst, src);
}
static void twofish_encrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
twofish_encrypt(ctx, length, dst, src);
}
static void twofish_decrypt_native(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
twofish_decrypt(ctx, length, dst, src);
}
static void aes_encrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
const QCryptoNettleAES *aesctx = ctx;
aes_encrypt(&aesctx->enc, length, dst, src);
}
static void aes_decrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
const QCryptoNettleAES *aesctx = ctx;
aes_decrypt(&aesctx->dec, length, dst, src);
}
static void des_encrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
des_encrypt(ctx, length, dst, src);
}
static void des_decrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
des_decrypt(ctx, length, dst, src);
}
static void des3_encrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
des3_encrypt(ctx, length, dst, src);
}
static void des3_decrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
des3_decrypt(ctx, length, dst, src);
}
static void cast128_encrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
cast128_encrypt(ctx, length, dst, src);
}
static void cast128_decrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
cast128_decrypt(ctx, length, dst, src);
}
static void serpent_encrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
serpent_encrypt(ctx, length, dst, src);
}
static void serpent_decrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
serpent_decrypt(ctx, length, dst, src);
}
static void twofish_encrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
twofish_encrypt(ctx, length, dst, src);
}
static void twofish_decrypt_wrapper(const void *ctx, size_t length,
uint8_t *dst, const uint8_t *src)
{
twofish_decrypt(ctx, length, dst, src);
}
typedef struct QCryptoCipherNettle QCryptoCipherNettle;
struct QCryptoCipherNettle {
/* Primary cipher context for all modes */
void *ctx;
/* Second cipher context for XTS mode only */
void *ctx_tweak;
/* Cipher callbacks for both contexts */
QCryptoCipherNettleFuncNative alg_encrypt_native;
QCryptoCipherNettleFuncNative alg_decrypt_native;
QCryptoCipherNettleFuncWrapper alg_encrypt_wrapper;
QCryptoCipherNettleFuncWrapper alg_decrypt_wrapper;
/* Initialization vector or Counter */
uint8_t *iv;
size_t blocksize;
};
bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode)
{
switch (alg) {
case QCRYPTO_CIPHER_ALG_DES_RFB:
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_192:
case QCRYPTO_CIPHER_ALG_TWOFISH_256:
break;
default:
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;
}
}
static void
qcrypto_nettle_cipher_free_ctx(QCryptoCipherNettle *ctx)
{
if (!ctx) {
return;
}
g_free(ctx->iv);
g_free(ctx->ctx);
g_free(ctx->ctx_tweak);
g_free(ctx);
}
static QCryptoCipherNettle *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode,
const uint8_t *key,
size_t nkey,
Error **errp)
{
QCryptoCipherNettle *ctx;
uint8_t *rfbkey;
switch (mode) {
case QCRYPTO_CIPHER_MODE_ECB:
case QCRYPTO_CIPHER_MODE_CBC:
case QCRYPTO_CIPHER_MODE_XTS:
case QCRYPTO_CIPHER_MODE_CTR:
break;
default:
error_setg(errp, "Unsupported cipher mode %s",
QCryptoCipherMode_str(mode));
return NULL;
}
if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
return NULL;
}
ctx = g_new0(QCryptoCipherNettle, 1);
switch (alg) {
case QCRYPTO_CIPHER_ALG_DES_RFB:
ctx->ctx = g_new0(struct des_ctx, 1);
rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
des_set_key(ctx->ctx, rfbkey);
g_free(rfbkey);
ctx->alg_encrypt_native = des_encrypt_native;
ctx->alg_decrypt_native = des_decrypt_native;
ctx->alg_encrypt_wrapper = des_encrypt_wrapper;
ctx->alg_decrypt_wrapper = des_decrypt_wrapper;
ctx->blocksize = DES_BLOCK_SIZE;
break;
case QCRYPTO_CIPHER_ALG_3DES:
ctx->ctx = g_new0(struct des3_ctx, 1);
des3_set_key(ctx->ctx, key);
ctx->alg_encrypt_native = des3_encrypt_native;
ctx->alg_decrypt_native = des3_decrypt_native;
ctx->alg_encrypt_wrapper = des3_encrypt_wrapper;
ctx->alg_decrypt_wrapper = des3_decrypt_wrapper;
ctx->blocksize = DES3_BLOCK_SIZE;
break;
case QCRYPTO_CIPHER_ALG_AES_128:
case QCRYPTO_CIPHER_ALG_AES_192:
case QCRYPTO_CIPHER_ALG_AES_256:
ctx->ctx = g_new0(QCryptoNettleAES, 1);
if (mode == QCRYPTO_CIPHER_MODE_XTS) {
ctx->ctx_tweak = g_new0(QCryptoNettleAES, 1);
nkey /= 2;
aes_set_encrypt_key(&((QCryptoNettleAES *)ctx->ctx)->enc,
nkey, key);
aes_set_decrypt_key(&((QCryptoNettleAES *)ctx->ctx)->dec,
nkey, key);
aes_set_encrypt_key(&((QCryptoNettleAES *)ctx->ctx_tweak)->enc,
nkey, key + nkey);
aes_set_decrypt_key(&((QCryptoNettleAES *)ctx->ctx_tweak)->dec,
nkey, key + nkey);
} else {
aes_set_encrypt_key(&((QCryptoNettleAES *)ctx->ctx)->enc,
nkey, key);
aes_set_decrypt_key(&((QCryptoNettleAES *)ctx->ctx)->dec,
nkey, key);
}
ctx->alg_encrypt_native = aes_encrypt_native;
ctx->alg_decrypt_native = aes_decrypt_native;
ctx->alg_encrypt_wrapper = aes_encrypt_wrapper;
ctx->alg_decrypt_wrapper = aes_decrypt_wrapper;
ctx->blocksize = AES_BLOCK_SIZE;
break;
case QCRYPTO_CIPHER_ALG_CAST5_128:
ctx->ctx = g_new0(struct cast128_ctx, 1);
if (mode == QCRYPTO_CIPHER_MODE_XTS) {
ctx->ctx_tweak = g_new0(struct cast128_ctx, 1);
nkey /= 2;
cast5_set_key(ctx->ctx, nkey, key);
cast5_set_key(ctx->ctx_tweak, nkey, key + nkey);
} else {
cast5_set_key(ctx->ctx, nkey, key);
}
ctx->alg_encrypt_native = cast128_encrypt_native;
ctx->alg_decrypt_native = cast128_decrypt_native;
ctx->alg_encrypt_wrapper = cast128_encrypt_wrapper;
ctx->alg_decrypt_wrapper = cast128_decrypt_wrapper;
ctx->blocksize = CAST128_BLOCK_SIZE;
break;
case QCRYPTO_CIPHER_ALG_SERPENT_128:
case QCRYPTO_CIPHER_ALG_SERPENT_192:
case QCRYPTO_CIPHER_ALG_SERPENT_256:
ctx->ctx = g_new0(struct serpent_ctx, 1);
if (mode == QCRYPTO_CIPHER_MODE_XTS) {
ctx->ctx_tweak = g_new0(struct serpent_ctx, 1);
nkey /= 2;
serpent_set_key(ctx->ctx, nkey, key);
serpent_set_key(ctx->ctx_tweak, nkey, key + nkey);
} else {
serpent_set_key(ctx->ctx, nkey, key);
}
ctx->alg_encrypt_native = serpent_encrypt_native;
ctx->alg_decrypt_native = serpent_decrypt_native;
ctx->alg_encrypt_wrapper = serpent_encrypt_wrapper;
ctx->alg_decrypt_wrapper = serpent_decrypt_wrapper;
ctx->blocksize = SERPENT_BLOCK_SIZE;
break;
case QCRYPTO_CIPHER_ALG_TWOFISH_128:
case QCRYPTO_CIPHER_ALG_TWOFISH_192:
case QCRYPTO_CIPHER_ALG_TWOFISH_256:
ctx->ctx = g_new0(struct twofish_ctx, 1);
if (mode == QCRYPTO_CIPHER_MODE_XTS) {
ctx->ctx_tweak = g_new0(struct twofish_ctx, 1);
nkey /= 2;
twofish_set_key(ctx->ctx, nkey, key);
twofish_set_key(ctx->ctx_tweak, nkey, key + nkey);
} else {
twofish_set_key(ctx->ctx, nkey, key);
}
ctx->alg_encrypt_native = twofish_encrypt_native;
ctx->alg_decrypt_native = twofish_decrypt_native;
ctx->alg_encrypt_wrapper = twofish_encrypt_wrapper;
ctx->alg_decrypt_wrapper = twofish_decrypt_wrapper;
ctx->blocksize = TWOFISH_BLOCK_SIZE;
break;
default:
error_setg(errp, "Unsupported cipher algorithm %s",
QCryptoCipherAlgorithm_str(alg));
goto error;
}
if (mode == QCRYPTO_CIPHER_MODE_XTS &&
ctx->blocksize != XTS_BLOCK_SIZE) {
error_setg(errp, "Cipher block size %zu must equal XTS block size %d",
ctx->blocksize, XTS_BLOCK_SIZE);
goto error;
}
ctx->iv = g_new0(uint8_t, ctx->blocksize);
return ctx;
error:
qcrypto_nettle_cipher_free_ctx(ctx);
return NULL;
}
static void
qcrypto_nettle_cipher_ctx_free(QCryptoCipher *cipher)
{
QCryptoCipherNettle *ctx;
ctx = cipher->opaque;
qcrypto_nettle_cipher_free_ctx(ctx);
}
static int
qcrypto_nettle_cipher_encrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherNettle *ctx = cipher->opaque;
if (len % ctx->blocksize) {
error_setg(errp, "Length %zu must be a multiple of block size %zu",
len, ctx->blocksize);
return -1;
}
switch (cipher->mode) {
case QCRYPTO_CIPHER_MODE_ECB:
ctx->alg_encrypt_wrapper(ctx->ctx, len, out, in);
break;
case QCRYPTO_CIPHER_MODE_CBC:
cbc_encrypt(ctx->ctx, ctx->alg_encrypt_native,
ctx->blocksize, ctx->iv,
len, out, in);
break;
case QCRYPTO_CIPHER_MODE_XTS:
xts_encrypt(ctx->ctx, ctx->ctx_tweak,
ctx->alg_encrypt_wrapper, ctx->alg_encrypt_wrapper,
ctx->iv, len, out, in);
break;
case QCRYPTO_CIPHER_MODE_CTR:
ctr_crypt(ctx->ctx, ctx->alg_encrypt_native,
ctx->blocksize, ctx->iv,
len, out, in);
break;
default:
error_setg(errp, "Unsupported cipher mode %s",
QCryptoCipherMode_str(cipher->mode));
return -1;
}
return 0;
}
static int
qcrypto_nettle_cipher_decrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherNettle *ctx = cipher->opaque;
if (len % ctx->blocksize) {
error_setg(errp, "Length %zu must be a multiple of block size %zu",
len, ctx->blocksize);
return -1;
}
switch (cipher->mode) {
case QCRYPTO_CIPHER_MODE_ECB:
ctx->alg_decrypt_wrapper(ctx->ctx, len, out, in);
break;
case QCRYPTO_CIPHER_MODE_CBC:
cbc_decrypt(ctx->ctx, ctx->alg_decrypt_native,
ctx->blocksize, ctx->iv,
len, out, in);
break;
case QCRYPTO_CIPHER_MODE_XTS:
xts_decrypt(ctx->ctx, ctx->ctx_tweak,
ctx->alg_encrypt_wrapper, ctx->alg_decrypt_wrapper,
ctx->iv, len, out, in);
break;
case QCRYPTO_CIPHER_MODE_CTR:
ctr_crypt(ctx->ctx, ctx->alg_encrypt_native,
ctx->blocksize, ctx->iv,
len, out, in);
break;
default:
error_setg(errp, "Unsupported cipher mode %s",
QCryptoCipherMode_str(cipher->mode));
return -1;
}
return 0;
}
static int
qcrypto_nettle_cipher_setiv(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
QCryptoCipherNettle *ctx = cipher->opaque;
if (niv != ctx->blocksize) {
error_setg(errp, "Expected IV size %zu not %zu",
ctx->blocksize, niv);
return -1;
}
memcpy(ctx->iv, iv, niv);
return 0;
}
static struct QCryptoCipherDriver qcrypto_cipher_lib_driver = {
.cipher_encrypt = qcrypto_nettle_cipher_encrypt,
.cipher_decrypt = qcrypto_nettle_cipher_decrypt,
.cipher_setiv = qcrypto_nettle_cipher_setiv,
.cipher_free = qcrypto_nettle_cipher_ctx_free,
};
