swarmapps

// BasicCryptoPPWrap example code
// By: Michael R. Rich, 2009
// swarmapps.wordpress.com
// This example code shows the use of all the BasicCryptoPPWrap functions
// This code is released to the public domain

#include <iostream>
#include <fstream>
#include "BasicCryptoPPWrap.h"
#include <string>
#include <sstream>
#include <stdio.h>

using namespace std;

int main (int argc, char * const argv[]) {
    bool err;
    string errMsg;

    // Encrypt and decrypt a string with a random key and initialization vector (iv)
    string key1 = BasicCryptoPPWrap::BitGen(128);   // We'll make a random 128 bit key
    string initVec1 = BasicCryptoPPWrap::ByteGen(16);   // AES uses 16 byte blocks, so the initVector must be 16 bytes

    // Here's what they look like
    cout << "key1: " << BasicCryptoPPWrap::HexEncode(key1) << "\n";
    cout << "initVec1: " << BasicCryptoPPWrap::HexEncode(initVec1) << "\n";

    string plainText = "I don't want anyone to see this!!";

    // encrypt it with the generic AES encryptor
    string cipherText = BasicCryptoPPWrap::EncryptStringAES(plainText, key1, initVec1,  err, errMsg);
    if (err) {
        cout << errMsg << "\n";
        return -1;
    }

    // Here's what it looks like
    cout << "Encrypted message: " << BasicCryptoPPWrap::HexEncode(cipherText) << "\n";

    // Now let's recover it!
    string recoveredText = BasicCryptoPPWrap::DecryptStringAES(cipherText, key1, initVec1,  err, errMsg);
    if (err) {
        cout << errMsg << "\n";
        return -1;
    }
    cout << "Plaintext Message 1: " << plainText << "\n";
    cout << "Recovered Message 1: " << recoveredText << "\n";

    // Now let's use the "MR" branded encryption and decryption.  This just stores the iv in the encrypted string, so we don't have to manage it
    // if you lose the iv, it's just like losing the key!  "MR" methods generate a random, meaningless iv that is worthless without the key
    // First lets generate a key from a plain text password
    string key2 = BasicCryptoPPWrap::hashSHA256("This is my password");
    plainText = "Four eyes only";
    cipherText = BasicCryptoPPWrap::MREncryptStringAES(plainText, key2,  err, errMsg);
    if (err) {
        cout << errMsg << "\n";
        return -1;
    }

    // Now recover the text with the matching decryption method
    recoveredText = BasicCryptoPPWrap::MRDecryptStringAES(cipherText, key2,  err, errMsg);
    if (err) {
        cout << errMsg << "\n";
        return -1;
    }

    cout << "Plaintext Message 2: " << plainText << "\n";
    cout << "Recovered Message 2: " << recoveredText << "\n";

    // Now let's try files!
    // We'll skip the generic encryption method and just use MR.  MR stores the iv as the first 16 bytes of the file.

    // Generate a file
    ofstream recipe("SecretSteakRecipe.txt");
    recipe << "Mike's Secret Steak Recipe\n1 ribeye\n1 bottle of Dale's Sauce\nStep 1: Marinate steak in ample amounts of Dale's Sauce for 15 minutes\n";
    recipe << "Step 2: Grill steak, flipping every 5 minutes until desired doneness is attained";
    recipe.close();

    // Now encrypt it with the MR methods
    // First open the infile
    ifstream infile("SecretSteakRecipe.txt", ios::binary); // always open your files in binary mode!

    // Now the outfile, this can be any outstream, but we'll save to disk first
    ofstream outfile("SuperSecretSteakRecipe.crypt", ios::binary);

    // encrypt it!
    BasicCryptoPPWrap::MREncryptFileAES(infile, outfile, key2,  err, errMsg);
    if (err) {
        cout << errMsg << "\n";
        return -1;
    }

    infile.close();
    outfile.close();

    // delete the old text file
    remove("SecretSteakRecipe.txt");

    // Now we'll decrypt, but do it to memory so we leave no trace!
    stringstream outBuffer;
    infile.open("SuperSecretSteakRecipe.crypt", ios::binary);

    // Decrypt it!
    BasicCryptoPPWrap::MRDecryptFileAES(infile, outBuffer, key2,  err, errMsg);
    if (err) {
        cout << errMsg << "\n";
        return -1;
    }

    // close and delete the encrypted file (you don't want me leaving files all over your hard drive do you?)
    infile.close();
    remove("SuperSecretSteakRecipe.crypt");

    // Now look at our buffer
    string aLine;
    while (getline(outBuffer, aLine)) {
        cout << aLine << "\n";
    }

    // And that's about it!
    return 0;
}