crypto/cipher-builtin.c.inc - qemu - 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 2.1 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"

 typedef struct QCryptoCipherBuiltinAESContext QCryptoCipherBuiltinAESContext;
 struct QCryptoCipherBuiltinAESContext {
     AES_KEY enc;
     AES_KEY dec;
 };

 typedef struct QCryptoCipherBuiltinAES QCryptoCipherBuiltinAES;
 struct QCryptoCipherBuiltinAES {
     QCryptoCipher base;
     QCryptoCipherBuiltinAESContext key;
     uint8_t iv[AES_BLOCK_SIZE];
 };


 static inline bool qcrypto_length_check(size_t len, size_t blocksize,
                                         Error **errp)
 {
     if (unlikely(len & (blocksize - 1))) {
         error_setg(errp, "Length %zu must be a multiple of block size %zu",
                    len, blocksize);
         return false;
     }
     return true;
 }

 static void qcrypto_cipher_ctx_free(QCryptoCipher *cipher)
 {
     g_free(cipher);
 }

 static int qcrypto_cipher_no_setiv(QCryptoCipher *cipher,
                                    const uint8_t *iv, size_t niv,
                                    Error **errp)
 {
     error_setg(errp, "Setting IV is not supported");
     return -1;
 }

 static void do_aes_encrypt_ecb(const void *vctx,
                                size_t len,
                                uint8_t *out,
                                const uint8_t *in)
 {
     const QCryptoCipherBuiltinAESContext *ctx = vctx;

     /* We have already verified that len % AES_BLOCK_SIZE == 0. */
     while (len) {
         AES_encrypt(in, out, &ctx->enc);
         in += AES_BLOCK_SIZE;
         out += AES_BLOCK_SIZE;
         len -= AES_BLOCK_SIZE;
     }
 }

 static void do_aes_decrypt_ecb(const void *vctx,
                                size_t len,
                                uint8_t *out,
                                const uint8_t *in)
 {
     const QCryptoCipherBuiltinAESContext *ctx = vctx;

     /* We have already verified that len % AES_BLOCK_SIZE == 0. */
     while (len) {
         AES_decrypt(in, out, &ctx->dec);
         in += AES_BLOCK_SIZE;
         out += AES_BLOCK_SIZE;
         len -= AES_BLOCK_SIZE;
     }
 }

 static void do_aes_encrypt_cbc(const AES_KEY *key,
                                size_t len,
                                uint8_t *out,
                                const uint8_t *in,
                                uint8_t *ivec)
 {
     uint8_t tmp[AES_BLOCK_SIZE];
     size_t n;

     /* We have already verified that len % AES_BLOCK_SIZE == 0. */
     while (len) {
         for (n = 0; n < AES_BLOCK_SIZE; ++n) {
             tmp[n] = in[n] ^ ivec[n];
         }
         AES_encrypt(tmp, out, key);
         memcpy(ivec, out, AES_BLOCK_SIZE);
         len -= AES_BLOCK_SIZE;
         in += AES_BLOCK_SIZE;
         out += AES_BLOCK_SIZE;
     }
 }

 static void do_aes_decrypt_cbc(const AES_KEY *key,
                                size_t len,
                                uint8_t *out,
                                const uint8_t *in,
                                uint8_t *ivec)
 {
     uint8_t tmp[AES_BLOCK_SIZE];
     size_t n;

     /* We have already verified that len % AES_BLOCK_SIZE == 0. */
     while (len) {
         memcpy(tmp, in, AES_BLOCK_SIZE);
         AES_decrypt(in, out, key);
         for (n = 0; n < AES_BLOCK_SIZE; ++n) {
             out[n] ^= ivec[n];
         }
         memcpy(ivec, tmp, AES_BLOCK_SIZE);
         len -= AES_BLOCK_SIZE;
         in += AES_BLOCK_SIZE;
         out += AES_BLOCK_SIZE;
     }
 }

 static int qcrypto_cipher_aes_encrypt_ecb(QCryptoCipher *cipher,
                                           const void *in, void *out,
                                           size_t len, Error **errp)
 {
     QCryptoCipherBuiltinAES *ctx
         = container_of(cipher, QCryptoCipherBuiltinAES, base);

     if (!qcrypto_length_check(len, AES_BLOCK_SIZE, errp)) {
         return -1;
     }
     do_aes_encrypt_ecb(&ctx->key, len, out, in);
     return 0;
 }

 static int qcrypto_cipher_aes_decrypt_ecb(QCryptoCipher *cipher,
                                           const void *in, void *out,
                                           size_t len, Error **errp)
 {
     QCryptoCipherBuiltinAES *ctx
         = container_of(cipher, QCryptoCipherBuiltinAES, base);

     if (!qcrypto_length_check(len, AES_BLOCK_SIZE, errp)) {
         return -1;
     }
     do_aes_decrypt_ecb(&ctx->key, len, out, in);
     return 0;
 }

 static int qcrypto_cipher_aes_encrypt_cbc(QCryptoCipher *cipher,
                                           const void *in, void *out,
                                           size_t len, Error **errp)
 {
     QCryptoCipherBuiltinAES *ctx
         = container_of(cipher, QCryptoCipherBuiltinAES, base);

     if (!qcrypto_length_check(len, AES_BLOCK_SIZE, errp)) {
         return -1;
     }
     do_aes_encrypt_cbc(&ctx->key.enc, len, out, in, ctx->iv);
     return 0;
 }

 static int qcrypto_cipher_aes_decrypt_cbc(QCryptoCipher *cipher,
                                           const void *in, void *out,
                                           size_t len, Error **errp)
 {
     QCryptoCipherBuiltinAES *ctx
         = container_of(cipher, QCryptoCipherBuiltinAES, base);

     if (!qcrypto_length_check(len, AES_BLOCK_SIZE, errp)) {
         return -1;
     }
     do_aes_decrypt_cbc(&ctx->key.dec, len, out, in, ctx->iv);
     return 0;
 }

 static int qcrypto_cipher_aes_setiv(QCryptoCipher *cipher, const uint8_t *iv,
                              size_t niv, Error **errp)
 {
     QCryptoCipherBuiltinAES *ctx
         = container_of(cipher, QCryptoCipherBuiltinAES, base);

     if (niv != AES_BLOCK_SIZE) {
         error_setg(errp, "IV must be %d bytes not %zu",
                    AES_BLOCK_SIZE, niv);
         return -1;
     }

     memcpy(ctx->iv, iv, AES_BLOCK_SIZE);
     return 0;
 }

 static const struct QCryptoCipherDriver qcrypto_cipher_aes_driver_ecb = {
     .cipher_encrypt = qcrypto_cipher_aes_encrypt_ecb,
     .cipher_decrypt = qcrypto_cipher_aes_decrypt_ecb,
     .cipher_setiv = qcrypto_cipher_no_setiv,
     .cipher_free = qcrypto_cipher_ctx_free,
 };

 static const struct QCryptoCipherDriver qcrypto_cipher_aes_driver_cbc = {
     .cipher_encrypt = qcrypto_cipher_aes_encrypt_cbc,
     .cipher_decrypt = qcrypto_cipher_aes_decrypt_cbc,
     .cipher_setiv = qcrypto_cipher_aes_setiv,
     .cipher_free = qcrypto_cipher_ctx_free,
 };

 bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
                              QCryptoCipherMode mode)
 {
     switch (alg) {
     case QCRYPTO_CIPHER_ALG_AES_128:
     case QCRYPTO_CIPHER_ALG_AES_192:
     case QCRYPTO_CIPHER_ALG_AES_256:
         switch (mode) {
         case QCRYPTO_CIPHER_MODE_ECB:
         case QCRYPTO_CIPHER_MODE_CBC:
             return true;
         default:
             return false;
         }
         break;
     default:
         return false;
     }
 }

 static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
                                              QCryptoCipherMode mode,
                                              const uint8_t *key,
                                              size_t nkey,
                                              Error **errp)
 {
     if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
         return NULL;
     }

     switch (alg) {
     case QCRYPTO_CIPHER_ALG_AES_128:
     case QCRYPTO_CIPHER_ALG_AES_192:
     case QCRYPTO_CIPHER_ALG_AES_256:
         {
             QCryptoCipherBuiltinAES *ctx;
             const QCryptoCipherDriver *drv;

             switch (mode) {
             case QCRYPTO_CIPHER_MODE_ECB:
                 drv = &qcrypto_cipher_aes_driver_ecb;
                 break;
             case QCRYPTO_CIPHER_MODE_CBC:
                 drv = &qcrypto_cipher_aes_driver_cbc;
                 break;
             default:
                 goto bad_mode;
             }

             ctx = g_new0(QCryptoCipherBuiltinAES, 1);
             ctx->base.driver = drv;

             if (AES_set_encrypt_key(key, nkey * 8, &ctx->key.enc)) {
                 error_setg(errp, "Failed to set encryption key");
                 goto error;
             }
             if (AES_set_decrypt_key(key, nkey * 8, &ctx->key.dec)) {
                 error_setg(errp, "Failed to set decryption key");
                 goto error;
             }

             return &ctx->base;

         error:
             g_free(ctx);
             return NULL;
         }

     default:
         error_setg(errp,
                    "Unsupported cipher algorithm %s",
                    QCryptoCipherAlgorithm_str(alg));
         return NULL;
     }

  bad_mode:
     error_setg(errp, "Unsupported cipher mode %s",
                QCryptoCipherMode_str(mode));
     return NULL;
 }
	/*
	* 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 2.1 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"

	typedef struct QCryptoCipherBuiltinAESContext QCryptoCipherBuiltinAESContext;
	struct QCryptoCipherBuiltinAESContext {
	AES_KEY enc;
	AES_KEY dec;
	};

	typedef struct QCryptoCipherBuiltinAES QCryptoCipherBuiltinAES;
	struct QCryptoCipherBuiltinAES {
	QCryptoCipher base;
	QCryptoCipherBuiltinAESContext key;
	uint8_t iv[AES_BLOCK_SIZE];
	};


	static inline bool qcrypto_length_check(size_t len, size_t blocksize,
	Error **errp)
	{
	if (unlikely(len & (blocksize - 1))) {
	error_setg(errp, "Length %zu must be a multiple of block size %zu",
	len, blocksize);
	return false;
	}
	return true;
	}

	static void qcrypto_cipher_ctx_free(QCryptoCipher *cipher)
	{
	g_free(cipher);
	}

	static int qcrypto_cipher_no_setiv(QCryptoCipher *cipher,
	const uint8_t *iv, size_t niv,
	Error **errp)
	{
	error_setg(errp, "Setting IV is not supported");
	return -1;
	}

	static void do_aes_encrypt_ecb(const void *vctx,
	size_t len,
	uint8_t *out,
	const uint8_t *in)
	{
	const QCryptoCipherBuiltinAESContext *ctx = vctx;

	/* We have already verified that len % AES_BLOCK_SIZE == 0. */
	while (len) {
	AES_encrypt(in, out, &ctx->enc);
	in += AES_BLOCK_SIZE;
	out += AES_BLOCK_SIZE;
	len -= AES_BLOCK_SIZE;
	}
	}

	static void do_aes_decrypt_ecb(const void *vctx,
	size_t len,
	uint8_t *out,
	const uint8_t *in)
	{
	const QCryptoCipherBuiltinAESContext *ctx = vctx;

	/* We have already verified that len % AES_BLOCK_SIZE == 0. */
	while (len) {
	AES_decrypt(in, out, &ctx->dec);
	in += AES_BLOCK_SIZE;
	out += AES_BLOCK_SIZE;
	len -= AES_BLOCK_SIZE;
	}
	}

	static void do_aes_encrypt_cbc(const AES_KEY *key,
	size_t len,
	uint8_t *out,
	const uint8_t *in,
	uint8_t *ivec)
	{
	uint8_t tmp[AES_BLOCK_SIZE];
	size_t n;

	/* We have already verified that len % AES_BLOCK_SIZE == 0. */
	while (len) {
	for (n = 0; n < AES_BLOCK_SIZE; ++n) {
	tmp[n] = in[n] ^ ivec[n];
	}
	AES_encrypt(tmp, out, key);
	memcpy(ivec, out, AES_BLOCK_SIZE);
	len -= AES_BLOCK_SIZE;
	in += AES_BLOCK_SIZE;
	out += AES_BLOCK_SIZE;
	}
	}

	static void do_aes_decrypt_cbc(const AES_KEY *key,
	size_t len,
	uint8_t *out,
	const uint8_t *in,
	uint8_t *ivec)
	{
	uint8_t tmp[AES_BLOCK_SIZE];
	size_t n;

	/* We have already verified that len % AES_BLOCK_SIZE == 0. */
	while (len) {
	memcpy(tmp, in, AES_BLOCK_SIZE);
	AES_decrypt(in, out, key);
	for (n = 0; n < AES_BLOCK_SIZE; ++n) {
	out[n] ^= ivec[n];
	}
	memcpy(ivec, tmp, AES_BLOCK_SIZE);
	len -= AES_BLOCK_SIZE;
	in += AES_BLOCK_SIZE;
	out += AES_BLOCK_SIZE;
	}
	}

	static int qcrypto_cipher_aes_encrypt_ecb(QCryptoCipher *cipher,
	const void in, void out,
	size_t len, Error **errp)
	{
	QCryptoCipherBuiltinAES *ctx
	= container_of(cipher, QCryptoCipherBuiltinAES, base);

	if (!qcrypto_length_check(len, AES_BLOCK_SIZE, errp)) {
	return -1;
	}
	do_aes_encrypt_ecb(&ctx->key, len, out, in);
	return 0;
	}

	static int qcrypto_cipher_aes_decrypt_ecb(QCryptoCipher *cipher,
	const void in, void out,
	size_t len, Error **errp)
	{
	QCryptoCipherBuiltinAES *ctx
	= container_of(cipher, QCryptoCipherBuiltinAES, base);

	if (!qcrypto_length_check(len, AES_BLOCK_SIZE, errp)) {
	return -1;
	}
	do_aes_decrypt_ecb(&ctx->key, len, out, in);
	return 0;
	}

	static int qcrypto_cipher_aes_encrypt_cbc(QCryptoCipher *cipher,
	const void in, void out,
	size_t len, Error **errp)
	{
	QCryptoCipherBuiltinAES *ctx
	= container_of(cipher, QCryptoCipherBuiltinAES, base);

	if (!qcrypto_length_check(len, AES_BLOCK_SIZE, errp)) {
	return -1;
	}
	do_aes_encrypt_cbc(&ctx->key.enc, len, out, in, ctx->iv);
	return 0;
	}

	static int qcrypto_cipher_aes_decrypt_cbc(QCryptoCipher *cipher,
	const void in, void out,
	size_t len, Error **errp)
	{
	QCryptoCipherBuiltinAES *ctx
	= container_of(cipher, QCryptoCipherBuiltinAES, base);

	if (!qcrypto_length_check(len, AES_BLOCK_SIZE, errp)) {
	return -1;
	}
	do_aes_decrypt_cbc(&ctx->key.dec, len, out, in, ctx->iv);
	return 0;
	}

	static int qcrypto_cipher_aes_setiv(QCryptoCipher cipher, const uint8_t iv,
	size_t niv, Error **errp)
	{
	QCryptoCipherBuiltinAES *ctx
	= container_of(cipher, QCryptoCipherBuiltinAES, base);

	if (niv != AES_BLOCK_SIZE) {
	error_setg(errp, "IV must be %d bytes not %zu",
	AES_BLOCK_SIZE, niv);
	return -1;
	}

	memcpy(ctx->iv, iv, AES_BLOCK_SIZE);
	return 0;
	}

	static const struct QCryptoCipherDriver qcrypto_cipher_aes_driver_ecb = {
	.cipher_encrypt = qcrypto_cipher_aes_encrypt_ecb,
	.cipher_decrypt = qcrypto_cipher_aes_decrypt_ecb,
	.cipher_setiv = qcrypto_cipher_no_setiv,
	.cipher_free = qcrypto_cipher_ctx_free,
	};

	static const struct QCryptoCipherDriver qcrypto_cipher_aes_driver_cbc = {
	.cipher_encrypt = qcrypto_cipher_aes_encrypt_cbc,
	.cipher_decrypt = qcrypto_cipher_aes_decrypt_cbc,
	.cipher_setiv = qcrypto_cipher_aes_setiv,
	.cipher_free = qcrypto_cipher_ctx_free,
	};

	bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
	QCryptoCipherMode mode)
	{
	switch (alg) {
	case QCRYPTO_CIPHER_ALG_AES_128:
	case QCRYPTO_CIPHER_ALG_AES_192:
	case QCRYPTO_CIPHER_ALG_AES_256:
	switch (mode) {
	case QCRYPTO_CIPHER_MODE_ECB:
	case QCRYPTO_CIPHER_MODE_CBC:
	return true;
	default:
	return false;
	}
	break;
	default:
	return false;
	}
	}

	static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
	QCryptoCipherMode mode,
	const uint8_t *key,
	size_t nkey,
	Error **errp)
	{
	if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
	return NULL;
	}

	switch (alg) {
	case QCRYPTO_CIPHER_ALG_AES_128:
	case QCRYPTO_CIPHER_ALG_AES_192:
	case QCRYPTO_CIPHER_ALG_AES_256:
	{
	QCryptoCipherBuiltinAES *ctx;
	const QCryptoCipherDriver *drv;

	switch (mode) {
	case QCRYPTO_CIPHER_MODE_ECB:
	drv = &qcrypto_cipher_aes_driver_ecb;
	break;
	case QCRYPTO_CIPHER_MODE_CBC:
	drv = &qcrypto_cipher_aes_driver_cbc;
	break;
	default:
	goto bad_mode;
	}

	ctx = g_new0(QCryptoCipherBuiltinAES, 1);
	ctx->base.driver = drv;

	if (AES_set_encrypt_key(key, nkey * 8, &ctx->key.enc)) {
	error_setg(errp, "Failed to set encryption key");
	goto error;
	}
	if (AES_set_decrypt_key(key, nkey * 8, &ctx->key.dec)) {
	error_setg(errp, "Failed to set decryption key");
	goto error;
	}

	return &ctx->base;

	error:
	g_free(ctx);
	return NULL;
	}

	default:
	error_setg(errp,
	"Unsupported cipher algorithm %s",
	QCryptoCipherAlgorithm_str(alg));
	return NULL;
	}

	bad_mode:
	error_setg(errp, "Unsupported cipher mode %s",
	QCryptoCipherMode_str(mode));
	return NULL;
	}