crypto/cipher-builtin.c - qemu-android - Git at Google

 /*
  * 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"

 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 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 &&
         cipher->mode != QCRYPTO_CIPHER_MODE_XTS) {
         error_setg(errp, "Unsupported cipher mode %d", cipher->mode);
         return -1;
     }

     ctxt = g_new0(QCryptoCipherBuiltin, 1);

     if (cipher->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;

     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->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;

     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, mode, 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;

     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);
 }


 int qcrypto_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);
 }


 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);
 }
	/*
	* 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"

	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 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 &&
	cipher->mode != QCRYPTO_CIPHER_MODE_XTS) {
	error_setg(errp, "Unsupported cipher mode %d", cipher->mode);
	return -1;
	}

	ctxt = g_new0(QCryptoCipherBuiltin, 1);

	if (cipher->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;

	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->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;

	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, mode, 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;

	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);
	}


	int qcrypto_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);
	}


	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);
	}