#ifndef CRYPTCLASSEVP_H
#define CRYPTCLASSEVP_H

#include "cryptclassbase.h"

#include <openssl/evp.h>
#include <openssl/err.h>
#include <stdexcept>

/**
* @author Walter Roth, 2015
* @brief The CryptClassEvp is a class for symmetric cryptography using OpenSSL's EVP API.
* Subclasses must overwrite the algorithm function to specify the algorithm to be used.
* The implementation of algorithm in this class returns a NULL-Cipher object (no encryption).
* This is quite useful for debugging.
*
*/
class CryptClassEvp : public CryptClassBase
{
public:
    CryptClassEvp();
    virtual ~CryptClassEvp();

    /**
    * @brief setAlgorithm Overwrite this function to specify the algorithm to be used.
    * @param cipher The cipher object e.g. EVP_bf_cbc() for Blowfish in CBC mode.
    */
    virtual const EVP_CIPHER *algorithm() = 0;

    /**
    * @brief encrypt Setup context and key and encrypt m_clearText into m_cryptText.
    */
    void encrypt();

    /**
    * @brief encrypt Setup context and key and decrypt m_cryptText into m_clearText.
    */
    void decrypt();

    /**
    * @brief handleOpenSslError Calls ERR_get_error and sends debug output to stderr.
    * @param file The __FILE__ makro
    * @param line The __LINE__ makro
    * @return
    */
    void handleOpenSslError();
};
#endif // CRYPTCLASSEVP_H