/*
 * Copyright (c) 2010 SURFnet bv
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*****************************************************************************
 OSSLEVPSymmetricAlgorithm.h

 OpenSSL symmetric algorithm implementation
 *****************************************************************************/

#ifndef _SOFTHSM_V2_OSSLEVPSYMMETRICALGORITHM_H
#define _SOFTHSM_V2_OSSLEVPSYMMETRICALGORITHM_H

#include <openssl/evp.h>
#include <string>
#include "config.h"
#include "SymmetricKey.h"
#include "SymmetricAlgorithm.h"

class OSSLEVPSymmetricAlgorithm : public SymmetricAlgorithm
{
public:
	// Constructor
	OSSLEVPSymmetricAlgorithm();

	// Destructor
	virtual ~OSSLEVPSymmetricAlgorithm();

	// Encryption functions
	virtual bool encryptInit(const SymmetricKey* key, const SymMode::Type mode = SymMode::CBC, const ByteString& IV = ByteString(), bool padding = true, size_t counterBits = 0, const ByteString& aad = ByteString(), size_t tagBytes = 0);
	virtual bool encryptUpdate(const ByteString& data, ByteString& encryptedData);
	virtual bool encryptFinal(ByteString& encryptedData);

	// Decryption functions
	virtual bool decryptInit(const SymmetricKey* key, const SymMode::Type mode = SymMode::CBC, const ByteString& IV = ByteString(), bool padding = true, size_t counterBits = 0, const ByteString& aad = ByteString(), size_t tagBytes = 0);
	virtual bool decryptUpdate(const ByteString& encryptedData, ByteString& data);
	virtual bool decryptFinal(ByteString& data);

	// Return the block size
	virtual size_t getBlockSize() const = 0;

	// Check if more bytes of data can be encrypted
	virtual bool checkMaximumBytes(unsigned long bytes);

protected:
	// Return the right EVP cipher for the operation
	virtual const EVP_CIPHER* getCipher() const = 0;

private:
	// The current EVP context
	EVP_CIPHER_CTX* pCurCTX;

	// The maximum bytes to encrypt/decrypt
	BIGNUM* maximumBytes;
	BIGNUM* counterBytes;
};

#endif // !_SOFTHSM_V2_OSSLEVPSYMMETRICALGORITHM_H