text: #ifndef __AES_H__
  #define __AES_H__
  
  #include "AES_config.h"
  #include <iostream>
  /*
   ---------------------------------------------------------------------------
   Copyright (c) 1998-2008, Brian Gladman, Worcester, UK. All rights reserved.
   LICENSE TERMS
   The redistribution and use of this software (with or without changes)
   is allowed without the payment of fees or royalties provided that:
    1. source code distributions include the above copyright notice, this
       list of conditions and the following disclaimer;
    2. binary distributions include the above copyright notice, this list
       of conditions and the following disclaimer in their documentation;
    3. the name of the copyright holder is not used to endorse products
       built using this software without specific written permission.
   DISCLAIMER
   This software is provided 'as is' with no explicit or implied warranties
   in respect of its properties, including, but not limited to, correctness
   and/or fitness for purpose.
   ---------------------------------------------------------------------------
   Issue 09/09/2006
   This is an AES implementation that uses only 8-bit byte operations on the
   cipher state.
   */
  
   /* code was modified by george spanos <spaniakos@gmail.com>
   * 16/12/14
   */
  
  class AES
  {
   public:
  
  /*  The following calls are for a precomputed key schedule
      NOTE: If the length_type used for the key length is an
      unsigned 8-bit character, a key length of 256 bits must
      be entered as a length in bytes (valid inputs are hence
      128, 192, 16, 24 and 32).
  */
  	/** \fn AES()
  	* \brief AES constructor
  	*
  	* This function initialized an instance of AES.
  	*/
  	AES();
  
  	/** Set the cipher key for the pre-keyed version.
  	 *  @param key[] pointer to the key string.
  	 *  @param keylen Integer that indicates the length of the key.
  	 *  @note NOTE: If the length_type used for the key length is an unsigned 8-bit character,
  	 *  a key length of 256 bits must be entered as a length in bytes
  	 *  (valid inputs are hence 128, 192, 16, 24 and 32).
  	 *
  	 */
  	byte set_key (byte key[], int keylen) ;
  
  	/** clean up subkeys after use.
  	 *
  	 */
  	void clean () ;  // delete key schedule after use
  
  	/** copying and xoring utilities.
  	 *  @param *AESt byte pointer of the AEStination array.
  	 *  @param *src byte pointer of the source array.
  	 *  @param n byte, indicating the sizeof the bytes to be copied.
  	 *  @note this is an alternative for memcpy(void *s1,const void *s2, site_t n),
  	 *  i have not updated the function in the implementation yet, but it is considered a future plan.
  	 *
  	 */
  	void copy_n_bytes (byte * AESt, byte * src, byte n) ;
  
  	/** Encrypt a single block of 16 bytes .
  	 *  @param plain[N_BLOCK] Array of the plaintext.
  	 *  @param cipher[N_BLOCK] Array of the ciphertext.
  	 *  @note The N_BLOCK is defined in AES_config.h as,
  	 *  @code #define N_ROW                   4
  	 *		  #define N_COL                   4
  	 *		  #define N_BLOCK   (N_ROW * N_COL)
  	 *	@endcode
  	 *  Changed to that will change the Block_size.
  	 *  @Return 0 if SUCCESS or -1 if FAILURE
  	 *
  	 */
  	byte encrypt (byte plain [N_BLOCK], byte cipher [N_BLOCK]) ;
  
  	/** CBC encrypt a number of blocks (input and return an IV).
  	 *
  	 *  @param *plain Pointer, points to the plaintex.
  	 *  @param *cipher Pointer, points to the ciphertext that will be created.
  	 *  @param n_block integer, indicated the number of blocks to be ciphered.
  	 *  @param iv[N_BLOCK] byte Array that holds the IV (initialization vector).
  	 *  @Return 0 if SUCCESS or -1 if FAILURE
  	 *
  	 */
  	byte cbc_encrypt (byte * plain, byte * cipher, int n_block, byte iv [N_BLOCK]) ;
  
  	/** CBC encrypt a number of blocks (input and return an IV).
  	 *
  	 *  @param *plain Pointer, points to the plaintex.
  	 *  @param *cipher Pointer, points to the ciphertext that will be created.
  	 *  @param n_block integer, indicated the number of blocks to be ciphered.
  	 *  @Return 0 if SUCCESS or -1 if FAILURE
  	 *
  	 */
  	byte cbc_encrypt (byte * plain, byte * cipher, int n_block) ;
  
  
  	/**  Decrypt a single block of 16 bytes
  	 *  @param cipher[N_BLOCK] Array of the ciphertext.
  	 *  @param plain[N_BLOCK] Array of the plaintext.
  	 *  @note The N_BLOCK is defined in AES_config.h as,
  	 *  @code #define N_ROW                   4
  	 *		  #define N_COL                   4
  	 *		  #define N_BLOCK   (N_ROW * N_COL)
  	 *	@endcode
  	 *  Changed to that will change the Block_size.
  	 *  @Return 0 if SUCCESS or -1 if FAILURE
  	 *
  	 */
  	byte decrypt (byte cipher [N_BLOCK], byte plain [N_BLOCK]) ;
  
  	/** CBC decrypt a number of blocks (input and return an IV)
  	 *
  	 *  @param *cipher Pointer, points to the ciphertext that will be created.
  	 *  @param *plain Pointer, points to the plaintex.
  	 *  @param n_block integer, indicated the number of blocks to be ciphered.
  	 *  @param iv[N_BLOCK] byte Array that holds the IV (initialization vector).
  	 *  @Return 0 if SUCCESS or -1 if FAILURE
  	 *
  	 */
  	byte cbc_decrypt (byte * cipher, byte * plain, int n_block, byte iv [N_BLOCK]) ;
  
  	/** CBC decrypt a number of blocks (input and return an IV)
  	 *
  	 *  @param *cipher Pointer, points to the ciphertext that will be created.
  	 *  @param *plain Pointer, points to the plaintex.
  	 *  @param n_block integer, indicated the number of blocks to be ciphered.
  	 *  @Return 0 if SUCCESS or -1 if FAILURE
  	 *
  	 */
  	byte cbc_decrypt (byte * cipher, byte * plain, int n_block) ;
  
  	/** Sets IV (initialization vector) and IVC (IV counter).
  	 *  This function changes the ivc and iv variables needed for AES.
  	 *
  	 *  @param IVCl int or hex value of iv , ex. 0x0000000000000001
  	 *  @note example:
  	 *  @code unsigned long long int my_iv = 01234567; @endcode
  	*/
  	void set_IV(unsigned long long int IVCl);
  	// void set_IV(unsigned char * IVCl);
  
  	/** increase the iv (initialization vector) and IVC (IV counter) by 1
  	 *
  	 *  This function increased the VI by one step in order to have a different IV each time
  	 *
  	*/
  	void iv_inc();
  
  	/** Getter method for size
  	 *
  	 * This function return the size
  	 * @return an integer, that is the size of the of the padded plaintext,
  	 * thus, the size of the ciphertext.
  	 */
  	int get_size();
  
  	/** Setter method for size
  	 *
  	 * This function sets the size of the plaintext+pad
  	 *
  	 */
  	void set_size(int sizel);
  
    int get_pad();
  
  	/** Getter method for IV
  	*
  	* This function return the IV
  	* @param out byte pointer that gets the IV.
  	* @return none, the IV is writed to the out pointer.
  	*/
  	void get_IV(byte *out);
  
  	/** Calculates the size of the plaintext and the padding.
  	 *
  	 * Calculates the size of theplaintext with the padding
  	 * and the size of the padding needed. Moreover it stores them in their class variables.
  	 *
  	 * @param p_size the size of the byte array ex sizeof(plaintext)
  	*/
  	void calc_size_n_pad(int p_size);
  
  	/** Pads the plaintext
  	 *
  	 * This function pads the plaintext and returns an char array with the
  	 * plaintext and the padding in order for the plaintext to be compatible with
  	 * 16bit size blocks required by AES
  	 *
  	 * @param in the string of the plaintext in a byte array
  	 * @param out The string of the out array.
  	 * @return no return, The padded plaintext is stored in the out pointer.
  	 */
  	void padPlaintext(void* in,byte* out);
  
  	/** Check the if the padding is correct.
  	 *
  	 * This functions checks the padding of the plaintext.
  	 *
  	 * @param in the string of the plaintext in a byte array
  	 * @param size the size of the string
  	 * @return true if correct / false if not
  	 */
  	bool CheckPad(byte* in,int size);
  
  	std::string getDecryptStr(byte ori[], bool p_pad = true);
  
  	/** Prints the array given.
  	 *
  	 * This function prints the given array and pad,
  	 * It is mainlly used for debugging purpuses or to output the string.
  	 *
  	 * @param output[] the string of the text in a byte array
  	 * @param p_pad optional, used to print with out the padding characters
  	*/
  	void printArray(byte output[],bool p_pad = true);
  
  	/** Prints the array given.
  	 *
  	 * This function prints the given array in Hexadecimal.
  	 *
  	 * @param output[] the string of the text in a byte array
  	 * @param sizel the size of the array.
  	*/
  	void printArray(byte output[],int sizel);
  
  	/** User friendly implementation of AES-CBC encryption.
  	 *
  	 * @param *plain pointer to the plaintext
  	 * @param size_p size of the plaintext
  	 * @param *cipher pointer to the ciphertext
  	 * @param *key pointer to the key that will be used.
  	 * @param bits bits of the encryption/decrpytion
  	 * @param ivl[N_BLOCK] the initialization vector IV that will be used for encryption.
  	 * @note The key will be stored in class variable.
  	 */
  	void do_aes_encrypt(byte *plain,int size_p,byte *cipher,byte *key, int bits, byte ivl [N_BLOCK]);
  
  	/** User friendly implementation of AES-CBC encryption.
  	 *
  	 * @param *plain pointer to the plaintext
  	 * @param size_p size of the plaintext
  	 * @param *cipher pointer to the ciphertext
  	 * @param *key pointer to the key that will be used.
  	 * @param bits bits of the encryption/decrpytion
  	 * @note The key will be stored in class variable.
  	 */
  	void do_aes_encrypt(byte *plain,int size_p,byte *cipher,byte *key, int bits);
  
  	/** User friendly implementation of AES-CBC decryption.
  	 *
  	 * @param *cipher pointer to the ciphertext
  	 * @param size_c size of the ciphertext
  	 * @param *plain pointer to the plaintext
  	 * @param *key pointer to the key that will be used.
  	 * @param bits bits of the encryption/decrpytion
  	 * @param ivl[N_BLOCK] the initialization vector IV that will be used for decryption.
  	 * @note The key will be stored in class variable.
  	 */
  	void do_aes_decrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits, byte ivl [N_BLOCK]);
  
  	/** User friendly implementation of AES-CBC decryption.
  	 *
  	 * @param *cipher pointer to the ciphertext
  	 * @param size_c size of the ciphertext
  	 * @param *plain pointer to the plaintext
  	 * @param *key pointer to the key that will be used.
  	 * @param bits bits of the encryption/decrpytion
  	 * @note The key will be stored in class variable.
  	 */
  	void do_aes_decrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits);
  
  	#if defined(AES_LINUX)
  		/**
  		 * used in linux in order to retrieve the time in milliseconds.
  		 *
  		 * @return returns the milliseconds in a double format.
  		 */
  		double millis();
  	#endif
   private:
    int round ;/**< holds the number of rounds to be used. */
    byte key_sched [KEY_SCHEDULE_BYTES] ;/**< holds the pre-computed key for the encryption/decrpytion. */
    unsigned long long int IVC;/**< holds the initialization vector counter in numerical format. */
    byte iv[16];/**< holds the initialization vector that will be used in the cipher. */
    int pad;/**< holds the size of the padding. */
    int size;/**< hold the size of the plaintext to be ciphered */
    #if defined(AES_LINUX)
  	timeval tv;/**< holds the time value on linux */
  	byte arr_pad[16];/**< holds the hexadecimal padding values on linux */
    #else
  	byte arr_pad[16] = { 0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,0x10 };/**< holds the hexadecimal padding values */
    #endif
  } ;
  
  
  #endif
  
  /**
   * @example aes.ino
   * <b>For Arduino</b><br>
   * <b>Updated: spaniakos 2015 </b><br>
   *
   * This is an example of how to use AES in CBC mode easily.
   * The text and keys can be either in HEX or String format.<br />
   */
  
   /**
   * @example aes.cpp
   * <b>For Rasberry pi</b><br>
   * <b>Updated: spaniakos 2015 </b><br>
   *
   * This is an example of how to use AES in CBC mode easily.
   * The text and keys can be either in HEX or String format.<br />
   */
  
   /**
   * @example test_vectors.ino
   * <b>For Arduino</b><br>
   * <b>Updated: spaniakos 2015 </b><br>
   *
   * This is an example of monte carlo test vectors, in order to justify the effectiveness of the algorithm.<br />
   * plus is a classical approach to the AES encryption library with out the easy to use add-on modifications.
   */
  
   /**
   * @example test_vectors.cpp
   * <b>For Rasberry pi</b><br>
   * <b>Updated: spaniakos 2015 </b><br>
   *
   * This is an example of monte carlo test vectors, in order to justify the effectiveness of the algorithm.<br />
   * plus is a classical approach to the AES encryption library with out the easy to use add-on modifications.
   */
  
  /**
   * @mainpage AES library for Arduino and Raspberry pi.
   *
   * @section Goals design Goals
   *
   * This library is AESigned to be...
   * @li Fast and efficient.
   * @li Able to effectively encrypt and decrypt any size of string.
   * @li Able to encrypt and decrypt using AES
   * @li Able to encrypt and decrypt using AES-CBC
   * @li Easy for the user to use in his programs.
   *
   * @section Acknowledgements Acknowledgements
   * This is an AES library for the Arduino, based on tzikis's AES library, which you can find <a href= "https://github.com/tzikis/arduino">here:</a>.<br />
   * Tzikis library was based on scottmac`s library, which you can find <a href="https://github.com/scottmac/arduino">here:</a><br />
   *
   * @section Installation Installation
   * <h3>Arduino</h3>
   * Create a folder named _AES_ in the _libraries_ folder inside your Arduino sketch folder. If the
   * libraries folder doesn't exist, create it. Then copy everything inside. (re)launch the Arduino IDE.<br />
   * You're done. Time for a mojito
   *
   * <h3>Raspberry  pi</h3>
   * <b>install</b><br /><br />
   *
   * sudo make install<br />
   * cd examples_Rpi<br />
   * make<br /><br />
   *
   * <b>What to do after changes to the library</b><br /><br />
   * sudo make clean<br />
   * sudo make install<br />
   * cd examples_Rpi<br />
   * make clean<br />
   * make<br /><br />
   * <b>What to do after changes to a sketch</b><br /><br />
   * cd examples_Rpi<br />
   * make <sketch><br /><br />
   * or <br />
   * make clean<br />
   * make<br /><br /><br />
   * <b>How to start a sketch</b><br /><br />
   * cd examples_Rpi<br />
   * sudo ./<sketch><br /><br />
   *
   * @section News News
   *
   * If issues are discovered with the documentation, please report them <a href="https://github.com/spaniakos/spaniakos.github.io/issues"> here</a>
   * @section Useful Useful References
   *
   * Please refer to:
   *
   * @li <a href="http://spaniakos.github.io/AES/classAES.html"><b>AES</b> Class Documentation</a>
   * @li <a href="https://github.com/spaniakos/AES/archive/master.zip"><b>Download</b></a>
   * @li <a href="https://github.com/spaniakos/AES/"><b>Source Code</b></a>
   * @li <a href="http://spaniakos.github.io/">All spaniakos Documentation Main Page</a>
   *
   * @section Board_Support Board Support
   *
   * Most standard Arduino based boards are supported:
   * - Arduino
   * - Intel Galileo support
   * - Raspberry Pi Support
   *
   * - The library has not been tested to other boards, but it should suppport ATMega 328 based boards,Mega Boards,Arduino Due,ATTiny board
   */
  
  