PPK-Sharp

Public/Private Key Encryption/Decryption with super simple integration with PHP and C#

What is PPK-Sharp?

PPK-Sharp is a quick and easy way to quickly get your foot in the door with PHP and C# based RSA public/private key encryption.

Requirements

PHP 7.0 or higher

You may be able to use PHP 4.2 or PHP 5, but do not submit an issue if you aren't using PHP 7.0 or higher

Any Version of .NET that supports BouncyCastle

Check Nuget for BouncyCastle, you'll need to add BouncyCastle to your project for this to work in C#

Dependencies

• [PHP] OpenSSL 1.1.1 or higher
• [C#] BouncyCastle 1.8.10 or higher for .Net Core 3.1 or equivilent BouncyCastle Package

Installation

PHP

• Drag and drop the files from php/ into your php project directory, or to a location on your web server.
• Ensure OpenSSL has been installed or enabled
• Write a PHP document that includes PPK.class.php

C#

• Drag and drop the files from csharp/ into your Visual Studio project directory
• Ensure BouncyCastle has been installed from Nuget in Visual Studio
• Write a class that uses PPK

Usage

Check the examples/ subfolder of both languages (eg. php/examples/) for more examples, but the basic usage is this:

PHP

<?php
include("PPK.class.php");
$pem = new PPK();
$encrypted_data = $pem->private->encrypt("Hello World");
$decrypted_data = $pem->public->decrypt($encrypted_data);

echo $decrypted_data; // Output: Hello World

C#

using System;
using PPKSharp;

namespace ConsoleTest
{
    class Program
    {
        static void Main(string[] args)
        {
            // you can provide your key by fetching it from a web server, or by reading it from a file.
            string PrivateKey = "... your public or private key here...";
            string PublicKey = "... your public or private key here...";

            PPK ppkPublic = new PPK(PublicKey); // key should be in PEM format
            PPK ppkPrivate = new PPK(PrivateKey); // key should be in PEM format
            
            string encrypted = ppkPublic.Encrypt("Hello World");

            string decrypted = ppkPrivate.Decrypt(encrypted);
            Console.WriteLine(decrypted);
        }
    }
}

Discrepancies between PHP and C#

• PPK-PHP supports generation of private keys, PPK-Sharp does not
• PPK-Sharp supports initialization using private OR public keys, PPK-PHP only supports initialization using private keys.
• PPK-Sharp cannot tell you what the public key of a private key is, but PPK-PHP can.