Java, Groovy and Javascript compatible coding library

Last week I worked on a Java/Groovy and JavaScript compatible coding library including:

• binary to hex representation (aka Hex class of commons codec)
• base64 implementation
• Tiny Encryption Algorithm (XXTEA)
• ASCII to binary conversion

The challenge is to get the same output in JavaScript and Java for the same input. JavaScript has no byte type so the only common binary type representation I found for both of them is to arrays of 32-bits integers,

Most of existing coding JavaScript library works based on String, but String encoding may vary between Java and JavaScript. Integers cannot. On Java-side, the library can work with bytes, integers and most of all NIO buffers.

Here is an excerpt of what you can do with this library. The result is the same in Java, Groovy and JavaScript providing the same input.

Java / Groovy

// ascii <-> binary conversion

String str = 'abcdefghijklmnopqrstuvwxyz'

IntBuffer buffer = ASCII.toIntBuffer(str)

assert str == ASCII.fromIntBuffer(buffer)

// hex representation

String str = '0123456789ABCDEF'

IntBuffer buffer = HEX.decodeHexAsInts(str)

assert str == HEX.encodeHexString(buffer)

// Base64

String str = Base64.encodeBase64String(buffer)

ByteBuffer buffer =  Base64.decodeBase64(str)

// TEA key generation

Random r = new SecureRandom()

IntBuffer key = IntBuffer.wrap([

    r.nextInt(), 

    r.nextInt(), 

    r.nextInt(), 

    r.nextInt()] as int[]) //128-bits keys

// TEA encryption

String data = "...." // > 128-bits data

IntBuffer buffer = ASCII.toIntBuffer(data)

XXTEA.encryptInPlace(buffer, key)

String b64 = Base64.encodeBase64String(buffer)

// TEA decryption

buffer = Base64.decodeBase64(b64).asIntBuffer()

XXTEA.decryptInPlace(buffer, key)

String clear_text = ASCII.fromIntBuffer(buffer)

JavaScript

// ascii <-> binary conversion

var str = 'abcdefghijklmnopqrstuvwxyz';

var int_array = ovea.crypto.ascii.toInts(str);

str ==  ovea.crypto.ascii.fromInts(int_array);

// hex representation

var str = '0123456789ABCDEF'v

var int_array = ovea.crypto.hex.decode(str);

str == ovea.crypto.hex.encode(int_array);

// Base64

var str = ovea.crypto.base64.encode(buffer);

var int_array =  ovea.crypto.base64.decode(str);

// TEA key generation

var key = [0, 1, 2, 3]  // 128-bits key

// TEA encryption

var data = "...." // > 128-bits data

var buffer = ovea.crypto.ascii.toInts(data);

ovea.crypto.xxtea.encryptInPlace(buffer, key);

var b64 = ovea.crypto.base64.encode(buffer);

// TEA decryption

var buffer = ovea.crypto.base64.decode(b64);
ovea.crypto.xxtea.decryptInPlace(buffer, key);
var clear_text = ovea.crypto.ascii.fromInts(buffer);

The project java-js-crypto is available on Ovea's GitHub. The license is Apache 2 and libraries are deployed in Maven2 Central Repository at:

http://repo1.maven.org/maven2/com/ovea/ovea-crypto/