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 "crypto/aes.h"
#include "crypto/desrfb.h"
typedef struct QCryptoCipherBuiltinAES QCryptoCipherBuiltinAES;
struct QCryptoCipherBuiltinAES {
AES_KEY encrypt_key;
AES_KEY decrypt_key;
uint8_t *iv;
size_t niv;
};
typedef struct QCryptoCipherBuiltinDESRFB QCryptoCipherBuiltinDESRFB;
struct QCryptoCipherBuiltinDESRFB {
uint8_t *key;
size_t nkey;
};
typedef struct QCryptoCipherBuiltin QCryptoCipherBuiltin;
struct QCryptoCipherBuiltin {
union {
QCryptoCipherBuiltinAES aes;
QCryptoCipherBuiltinDESRFB desrfb;
} state;
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->state.aes.iv);
g_free(ctxt);
cipher->opaque = NULL;
}
static int qcrypto_cipher_encrypt_aes(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
if (cipher->mode == QCRYPTO_CIPHER_MODE_ECB) {
const uint8_t *inptr = in;
uint8_t *outptr = out;
while (len) {
if (len > AES_BLOCK_SIZE) {
AES_encrypt(inptr, outptr, &ctxt->state.aes.encrypt_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, &ctxt->state.aes.encrypt_key);
memcpy(outptr, tmp2, len);
len = 0;
}
}
} else {
AES_cbc_encrypt(in, out, len,
&ctxt->state.aes.encrypt_key,
ctxt->state.aes.iv, 1);
}
return 0;
}
static int qcrypto_cipher_decrypt_aes(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
if (cipher->mode == QCRYPTO_CIPHER_MODE_ECB) {
const uint8_t *inptr = in;
uint8_t *outptr = out;
while (len) {
if (len > AES_BLOCK_SIZE) {
AES_decrypt(inptr, outptr, &ctxt->state.aes.decrypt_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, &ctxt->state.aes.decrypt_key);
memcpy(outptr, tmp2, len);
len = 0;
}
}
} else {
AES_cbc_encrypt(in, out, len,
&ctxt->state.aes.decrypt_key,
ctxt->state.aes.iv, 0);
}
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 != 16) {
error_setg(errp, "IV must be 16 bytes not %zu", niv);
return -1;
}
g_free(ctxt->state.aes.iv);
ctxt->state.aes.iv = g_new0(uint8_t, niv);
memcpy(ctxt->state.aes.iv, iv, niv);
ctxt->state.aes.niv = niv;
return 0;
}
static int qcrypto_cipher_init_aes(QCryptoCipher *cipher,
const uint8_t *key, size_t nkey,
Error **errp)
{
QCryptoCipherBuiltin *ctxt;
if (cipher->mode != QCRYPTO_CIPHER_MODE_CBC &&
cipher->mode != QCRYPTO_CIPHER_MODE_ECB) {
error_setg(errp, "Unsupported cipher mode %d", cipher->mode);
return -1;
}
ctxt = g_new0(QCryptoCipherBuiltin, 1);
if (AES_set_encrypt_key(key, nkey * 8, &ctxt->state.aes.encrypt_key) != 0) {
error_setg(errp, "Failed to set encryption key");
goto error;
}
if (AES_set_decrypt_key(key, nkey * 8, &ctxt->state.aes.decrypt_key) != 0) {
error_setg(errp, "Failed to set decryption key");
goto error;
}
ctxt->free = qcrypto_cipher_free_aes;
ctxt->setiv = qcrypto_cipher_setiv_aes;
ctxt->encrypt = qcrypto_cipher_encrypt_aes;
ctxt->decrypt = qcrypto_cipher_decrypt_aes;
cipher->opaque = ctxt;
return 0;
error:
g_free(ctxt);
return -1;
}
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 int qcrypto_cipher_init_des_rfb(QCryptoCipher *cipher,
const uint8_t *key, size_t nkey,
Error **errp)
{
QCryptoCipherBuiltin *ctxt;
if (cipher->mode != QCRYPTO_CIPHER_MODE_ECB) {
error_setg(errp, "Unsupported cipher mode %d", cipher->mode);
return -1;
}
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->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;
cipher->opaque = ctxt;
return 0;
}
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;
cipher = g_new0(QCryptoCipher, 1);
cipher->alg = alg;
cipher->mode = mode;
if (!qcrypto_cipher_validate_key_length(alg, nkey, errp)) {
goto error;
}
switch (cipher->alg) {
case QCRYPTO_CIPHER_ALG_DES_RFB:
if (qcrypto_cipher_init_des_rfb(cipher, key, nkey, errp) < 0) {
goto error;
}
break;
case QCRYPTO_CIPHER_ALG_AES_128:
case QCRYPTO_CIPHER_ALG_AES_192:
case QCRYPTO_CIPHER_ALG_AES_256:
if (qcrypto_cipher_init_aes(cipher, key, nkey, errp) < 0) {
goto error;
}
break;
default:
error_setg(errp,
"Unsupported cipher algorithm %d", cipher->alg);
goto error;
}
return cipher;
error:
g_free(cipher);
return NULL;
}
void qcrypto_cipher_free(QCryptoCipher *cipher)
{
QCryptoCipherBuiltin *ctxt;
if (!cipher) {
return;
}
ctxt = cipher->opaque;
ctxt->free(cipher);
g_free(cipher);
}
int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
return ctxt->encrypt(cipher, in, out, len, errp);
}
int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
return ctxt->decrypt(cipher, in, out, len, errp);
}
int qcrypto_cipher_setiv(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp)
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
return ctxt->setiv(cipher, iv, niv, errp);
}