The purpose of this article is to provide a starting point for projects which require strongest encryption on multiple platforms. Sample code is provided here and on GitHub repositories in C++ (Windows and Linux), Java and C#. Recently, a Linux based dynamic library and a test program explaining how to use it is uploaded on GitHub. C++ on Linux x64 means it could be used for NodeJS as well by just creating a wrapper. Similarly, it could be used on Apple machines easily as well.
Introduction
While working in security, identity management and data protection fields for a while, I found a very few working examples in the public domain on cross platform encryption based on AES 256 GCM algorithm. This is the same algorithm used by Google when you access Gmail, etc.
This article may help you implement very strong cross platform encryption / decryption. The sample code is in C++, C# and Java. However, Java through JNI (Java Native Interface) and C# through COM, can call native C++ code, which in my testing appears to be much faster as compared to pure Java or C# implementations. Still, there are times when one wants to do it without calling a native C++ layer.
For C#, to achieve AES 256 GCM encryption, I used Bouncy Castle cryptographic libraries. The code snippets available with this article work perfectly for encryption and decryption across various platforms. I tested it to be working on Linux (using Mono Framework) and Windows.
For C++ layer, I utilized Crypto++. This library is cross platform compatible (Windows, Linux and others like Solaris etc.). Crypto++ is a robust and very well implemented open source cryptographic library.
This article is not intended for beginners nor is it to teach AES GCM algorithm.
This article sort of provides you a sample code to implement with your own modifications.
C++ is a little complicated. Download Crypto++ source code. Create a console project and add existing Crypto++ project to solution. Then set your console project as startup project and set build dependency order.
Copy paste code from the article and correct header files paths (like
pch.h
) You can add source code directories in project properties as well to fix paths. In the same way, you can correct path to Crypto++ compiled library or add it to your project properties.
Another purpose of this article is to combine all three major programming languages sample code at one place. You don't have to search through thousands of individual samples, some of them do not work as intended. The code sample here works without any issue.
Recently, a Linux based dynamic library and a test program explaining how to use it is uploaded on GitHub. C++ on Linux x64 means it could be used for NodeJS as well by just creating a wrapper. Similarly, it could be used on Apple machines easily as well.
Background
Cross Platform AES 256 GCM Encryption and Decryption (C++, C# and Java)
You can also read more about Crypto++ AES GCM implementation or algorithm itself
here
and
here
.
Similarly, details about BouncyCastle can be found
here
.
BouncyCastle .NET used in C# code is
here
.
C# Version
C++ Version
Java Version
Linux Lib Version
Windows C++ x64 DLL and Example Test Program
Using the Code
For C#
Please add reference:
BouncyCastle.Crypto
(
BouncyCastle.Crypto.dll
)
https://www.nuget.org/packages/BouncyCastle.Crypto.dll/
C# Test Console Application
using System;
namespace TestAES_GCM_256
class Program
static void Main(string[] args)
string hexKey =
"2192B39425BBD08B6E8E61C5D1F1BC9F428FC569FBC6F78C0BC48FCCDB0F42AE";
string hexIV = "E1E592E87225847C11D948684F3B070D";
string plainText = "Test encryption and decryption";
Console.WriteLine("Plain Text: " + plainText);
string encryptedText = AesGcm256.encrypt
(plainText, AesGcm256.HexToByte(hexKey), AesGcm256.HexToByte(hexIV));
Console.WriteLine("Encrypted base64 encoded: " + encryptedText);
string decryptedText = AesGcm256.decrypt
(encryptedText, AesGcm256.HexToByte(hexKey),
AesGcm256.HexToByte(hexIV));
Console.WriteLine("Decrypted Text: " + decryptedText);
if (plainText.Equals(decryptedText))
Console.WriteLine("Test Passed");
Console.WriteLine("Test Failed");
