qemu-e2k/crypto/cipher-builtin.c

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/*
* QEMU Crypto cipher built-in 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/aes.h"
#include "crypto/desrfb.h"
#include "crypto/xts.h"
#include "cipherpriv.h"
typedef struct QCryptoCipherBuiltinAESContext QCryptoCipherBuiltinAESContext;
struct QCryptoCipherBuiltinAESContext {
AES_KEY enc;
AES_KEY dec;
};
typedef struct QCryptoCipherBuiltinAES QCryptoCipherBuiltinAES;
struct QCryptoCipherBuiltinAES {
QCryptoCipherBuiltinAESContext key;
QCryptoCipherBuiltinAESContext key_tweak;
uint8_t iv[AES_BLOCK_SIZE];
};
typedef struct QCryptoCipherBuiltinDESRFB QCryptoCipherBuiltinDESRFB;
struct QCryptoCipherBuiltinDESRFB {
uint8_t *key;
size_t nkey;
};
typedef struct QCryptoCipherBuiltin QCryptoCipherBuiltin;
struct QCryptoCipherBuiltin {
union {
QCryptoCipherBuiltinAES aes;
QCryptoCipherBuiltinDESRFB desrfb;
} state;
size_t blocksize;
void (*free)(QCryptoCipher *cipher);
int (*setiv)(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp);
int (*encrypt)(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp);
int (*decrypt)(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp);
};
static void qcrypto_cipher_free_aes(QCryptoCipher *cipher)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
g_free(ctxt);
cipher->opaque = NULL;
}
static void qcrypto_cipher_aes_ecb_encrypt(AES_KEY *key,
const void *in,
void *out,
size_t len)
{
const uint8_t *inptr = in;
uint8_t *outptr = out;
while (len) {
if (len > AES_BLOCK_SIZE) {
AES_encrypt(inptr, outptr, key);
inptr += AES_BLOCK_SIZE;
outptr += AES_BLOCK_SIZE;
len -= AES_BLOCK_SIZE;
} else {
uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
memcpy(tmp1, inptr, len);
/* Fill with 0 to avoid valgrind uninitialized reads */
memset(tmp1 + len, 0, sizeof(tmp1) - len);
AES_encrypt(tmp1, tmp2, key);
memcpy(outptr, tmp2, len);
len = 0;
}
}
}
static void qcrypto_cipher_aes_ecb_decrypt(AES_KEY *key,
const void *in,
void *out,
size_t len)
{
const uint8_t *inptr = in;
uint8_t *outptr = out;
while (len) {
if (len > AES_BLOCK_SIZE) {
AES_decrypt(inptr, outptr, key);
inptr += AES_BLOCK_SIZE;
outptr += AES_BLOCK_SIZE;
len -= AES_BLOCK_SIZE;
} else {
uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
memcpy(tmp1, inptr, len);
/* Fill with 0 to avoid valgrind uninitialized reads */
memset(tmp1 + len, 0, sizeof(tmp1) - len);
AES_decrypt(tmp1, tmp2, key);
memcpy(outptr, tmp2, len);
len = 0;
}
}
}
static void qcrypto_cipher_aes_xts_encrypt(const void *ctx,
size_t length,
uint8_t *dst,
const uint8_t *src)
{
const QCryptoCipherBuiltinAESContext *aesctx = ctx;
qcrypto_cipher_aes_ecb_encrypt((AES_KEY *)&aesctx->enc,
src, dst, length);
}
static void qcrypto_cipher_aes_xts_decrypt(const void *ctx,
size_t length,
uint8_t *dst,
const uint8_t *src)
{
const QCryptoCipherBuiltinAESContext *aesctx = ctx;
qcrypto_cipher_aes_ecb_decrypt((AES_KEY *)&aesctx->dec,
src, dst, length);
}
static int qcrypto_cipher_encrypt_aes(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
switch (cipher->mode) {
case QCRYPTO_CIPHER_MODE_ECB:
qcrypto_cipher_aes_ecb_encrypt(&ctxt->state.aes.key.enc,
in, out, len);
break;
case QCRYPTO_CIPHER_MODE_CBC:
AES_cbc_encrypt(in, out, len,
&ctxt->state.aes.key.enc,
ctxt->state.aes.iv, 1);
break;
case QCRYPTO_CIPHER_MODE_XTS:
xts_encrypt(&ctxt->state.aes.key,
&ctxt->state.aes.key_tweak,
qcrypto_cipher_aes_xts_encrypt,
qcrypto_cipher_aes_xts_decrypt,
ctxt->state.aes.iv,
len, out, in);
break;
default:
g_assert_not_reached();
}
return 0;
}
static int qcrypto_cipher_decrypt_aes(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
switch (cipher->mode) {
case QCRYPTO_CIPHER_MODE_ECB:
qcrypto_cipher_aes_ecb_decrypt(&ctxt->state.aes.key.dec,
in, out, len);
break;
case QCRYPTO_CIPHER_MODE_CBC:
AES_cbc_encrypt(in, out, len,
&ctxt->state.aes.key.dec,
ctxt->state.aes.iv, 0);
break;
case QCRYPTO_CIPHER_MODE_XTS:
xts_decrypt(&ctxt->state.aes.key,
&ctxt->state.aes.key_tweak,
qcrypto_cipher_aes_xts_encrypt,
qcrypto_cipher_aes_xts_decrypt,
ctxt->state.aes.iv,
len, out, in);
break;
default:
g_assert_not_reached();
}
return 0;
}
static int qcrypto_cipher_setiv_aes(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
if (niv != AES_BLOCK_SIZE) {
error_setg(errp, "IV must be %d bytes not %zu",
AES_BLOCK_SIZE, niv);
return -1;
}
memcpy(ctxt->state.aes.iv, iv, AES_BLOCK_SIZE);
return 0;
}
static QCryptoCipherBuiltin *
qcrypto_cipher_init_aes(QCryptoCipherMode mode,
const uint8_t *key, size_t nkey,
Error **errp)
{
QCryptoCipherBuiltin *ctxt;
if (mode != QCRYPTO_CIPHER_MODE_CBC &&
mode != QCRYPTO_CIPHER_MODE_ECB &&
mode != QCRYPTO_CIPHER_MODE_XTS) {
error_setg(errp, "Unsupported cipher mode %s",
QCryptoCipherMode_str(mode));
return NULL;
}
ctxt = g_new0(QCryptoCipherBuiltin, 1);
if (mode == QCRYPTO_CIPHER_MODE_XTS) {
if (AES_set_encrypt_key(key, nkey * 4, &ctxt->state.aes.key.enc) != 0) {
error_setg(errp, "Failed to set encryption key");
goto error;
}
if (AES_set_decrypt_key(key, nkey * 4, &ctxt->state.aes.key.dec) != 0) {
error_setg(errp, "Failed to set decryption key");
goto error;
}
if (AES_set_encrypt_key(key + (nkey / 2), nkey * 4,
&ctxt->state.aes.key_tweak.enc) != 0) {
error_setg(errp, "Failed to set encryption key");
goto error;
}
if (AES_set_decrypt_key(key + (nkey / 2), nkey * 4,
&ctxt->state.aes.key_tweak.dec) != 0) {
error_setg(errp, "Failed to set decryption key");
goto error;
}
} else {
if (AES_set_encrypt_key(key, nkey * 8, &ctxt->state.aes.key.enc) != 0) {
error_setg(errp, "Failed to set encryption key");
goto error;
}
if (AES_set_decrypt_key(key, nkey * 8, &ctxt->state.aes.key.dec) != 0) {
error_setg(errp, "Failed to set decryption key");
goto error;
}
}
ctxt->blocksize = AES_BLOCK_SIZE;
ctxt->free = qcrypto_cipher_free_aes;
ctxt->setiv = qcrypto_cipher_setiv_aes;
ctxt->encrypt = qcrypto_cipher_encrypt_aes;
ctxt->decrypt = qcrypto_cipher_decrypt_aes;
return ctxt;
error:
g_free(ctxt);
return NULL;
}
static void qcrypto_cipher_free_des_rfb(QCryptoCipher *cipher)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
g_free(ctxt->state.desrfb.key);
g_free(ctxt);
cipher->opaque = NULL;
}
static int qcrypto_cipher_encrypt_des_rfb(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
size_t i;
if (len % 8) {
error_setg(errp, "Buffer size must be multiple of 8 not %zu",
len);
return -1;
}
deskey(ctxt->state.desrfb.key, EN0);
for (i = 0; i < len; i += 8) {
des((void *)in + i, out + i);
}
return 0;
}
static int qcrypto_cipher_decrypt_des_rfb(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
size_t i;
if (len % 8) {
error_setg(errp, "Buffer size must be multiple of 8 not %zu",
len);
return -1;
}
deskey(ctxt->state.desrfb.key, DE1);
for (i = 0; i < len; i += 8) {
des((void *)in + i, out + i);
}
return 0;
}
static int qcrypto_cipher_setiv_des_rfb(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
error_setg(errp, "Setting IV is not supported");
return -1;
}
static QCryptoCipherBuiltin *
qcrypto_cipher_init_des_rfb(QCryptoCipherMode mode,
const uint8_t *key, size_t nkey,
Error **errp)
{
QCryptoCipherBuiltin *ctxt;
if (mode != QCRYPTO_CIPHER_MODE_ECB) {
error_setg(errp, "Unsupported cipher mode %s",
QCryptoCipherMode_str(mode));
return NULL;
}
ctxt = g_new0(QCryptoCipherBuiltin, 1);
ctxt->state.desrfb.key = g_new0(uint8_t, nkey);
memcpy(ctxt->state.desrfb.key, key, nkey);
ctxt->state.desrfb.nkey = nkey;
ctxt->blocksize = 8;
ctxt->free = qcrypto_cipher_free_des_rfb;
ctxt->setiv = qcrypto_cipher_setiv_des_rfb;
ctxt->encrypt = qcrypto_cipher_encrypt_des_rfb;
ctxt->decrypt = qcrypto_cipher_decrypt_des_rfb;
return ctxt;
}
bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode)
{
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:
break;
default:
return false;
}
switch (mode) {
case QCRYPTO_CIPHER_MODE_ECB:
case QCRYPTO_CIPHER_MODE_CBC:
case QCRYPTO_CIPHER_MODE_XTS:
return true;
case QCRYPTO_CIPHER_MODE_CTR:
return false;
default:
return false;
}
}
static QCryptoCipherBuiltin *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode,
const uint8_t *key,
size_t nkey,
Error **errp)
{
QCryptoCipherBuiltin *ctxt;
switch (mode) {
case QCRYPTO_CIPHER_MODE_ECB:
case QCRYPTO_CIPHER_MODE_CBC:
case QCRYPTO_CIPHER_MODE_XTS:
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;
}
switch (alg) {
case QCRYPTO_CIPHER_ALG_DES_RFB:
ctxt = qcrypto_cipher_init_des_rfb(mode, key, nkey, errp);
break;
case QCRYPTO_CIPHER_ALG_AES_128:
case QCRYPTO_CIPHER_ALG_AES_192:
case QCRYPTO_CIPHER_ALG_AES_256:
ctxt = qcrypto_cipher_init_aes(mode, key, nkey, errp);
break;
default:
error_setg(errp,
"Unsupported cipher algorithm %s",
QCryptoCipherAlgorithm_str(alg));
return NULL;
}
return ctxt;
}
static void
qcrypto_builtin_cipher_ctx_free(QCryptoCipher *cipher)
{
QCryptoCipherBuiltin *ctxt;
ctxt = cipher->opaque;
ctxt->free(cipher);
}
static int
qcrypto_builtin_cipher_encrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
if (len % ctxt->blocksize) {
error_setg(errp, "Length %zu must be a multiple of block size %zu",
len, ctxt->blocksize);
return -1;
}
return ctxt->encrypt(cipher, in, out, len, errp);
}
static int
qcrypto_builtin_cipher_decrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
if (len % ctxt->blocksize) {
error_setg(errp, "Length %zu must be a multiple of block size %zu",
len, ctxt->blocksize);
return -1;
}
return ctxt->decrypt(cipher, in, out, len, errp);
}
static int
qcrypto_builtin_cipher_setiv(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
return ctxt->setiv(cipher, iv, niv, errp);
}
static struct QCryptoCipherDriver qcrypto_cipher_lib_driver = {
.cipher_encrypt = qcrypto_builtin_cipher_encrypt,
.cipher_decrypt = qcrypto_builtin_cipher_decrypt,
.cipher_setiv = qcrypto_builtin_cipher_setiv,
.cipher_free = qcrypto_builtin_cipher_ctx_free,
};