/*
 * AESDemoClass.cpp
 *
 *  Created on: Sep 13, 2019
 *      Author: yulia
 */

#include <iostream>
#include <fstream>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <vector>
#include <openssl/aes.h>
#include "AESDemoClass.h"

using namespace std;

AESDemoClass::AESDemoClass() {

}

AESDemoClass::~AESDemoClass() {
}

/* AES key for Encryption and Decryption */
const static unsigned char aes_key[]={0x00,0x11,0x22,0x33,0x44,0x55,0x66,0x77,0x88,0x99,0xAA,0xBB,0xCC,0xDD,0xEE,0xFF};

void AESDemoClass::aesDemo(){
    /* Input data to encrypt */
    vector<char> input = readAllBytes("input.txt");

    int n = input.size();

    unsigned char aes_input[n];
    for (int i = 0; i < n; i++)
        aes_input[i] = input[i];

//  unsigned char aes_input[n] = arr;

    /* Init vector */
    unsigned char iv[AES_BLOCK_SIZE];
    memset(iv, 0x00, AES_BLOCK_SIZE);

    /* Buffers for Encryption and Decryption */
    unsigned char enc_out[sizeof(aes_input)];
    unsigned char dec_out[sizeof(aes_input)];

    /* AES-128 bit CBC Encryption */
    AES_KEY enc_key, dec_key;
    AES_set_encrypt_key(aes_key, sizeof(aes_key)*8, &enc_key);
    AES_cbc_encrypt(aes_input, enc_out, sizeof(aes_input), &enc_key, iv, AES_ENCRYPT);
    /* AES-128 bit CBC Decryption */
    memset(iv, 0x00, AES_BLOCK_SIZE); // don't forget to set iv vector again, else you can't decrypt data properly
    AES_set_decrypt_key(aes_key, sizeof(aes_key)*8, &dec_key); // Size of key is in bits
    AES_cbc_encrypt(enc_out, dec_out, sizeof(aes_input), &dec_key, iv, AES_DECRYPT);

    /* Printing and Verifying */
    print_data("\n Original ",aes_input, sizeof(aes_input)); // you can not print data as a string, because after Encryption its not ASCII

    print_data("\n Encrypted",enc_out, sizeof(enc_out));

    print_data("\n Decrypted",dec_out, sizeof(dec_out));

}

void AESDemoClass::print_data(const char *title, const void* data, int len)
{
    printf("%s : ",title);
    const unsigned char * p = (const unsigned char*)data;
    int i = 0;

    for (; i<len; ++i)
        printf("%02X ", *p++);

    printf("\n");
}

std::vector<char> AESDemoClass::readAllBytes(char const* filename){
    ifstream ifs(filename, ios::binary|ios::ate);
    ifstream::pos_type pos = ifs.tellg();

    std::vector<char> input(pos);

    ifs.seekg(0, ios::beg);
    ifs.read(&input[0], pos);

    return input;

}