Decr.java

/* de-obfuscate kettle passwords */

import java.math.BigInteger;

public class Decr {
	private static final int RADIX = 16;
	private static final String SEED = "0933910847463829827159347601486730416058";

	public static void main(String[] args) {
		if (args.length!=1) {
			printOptions();
			System.exit(9);
		}

		String obfuscated = args[0];

		String password = Decr.decryptPassword(obfuscated);
		System.out.println(password);
		System.exit(0);
	}

	public static final String decryptPassword(String encrypted) {
		if (encrypted==null) return "";
		if (encrypted.length()==0) return "";

		BigInteger bi_confuse  = new BigInteger(SEED);

		try {
			BigInteger bi_r1 = new BigInteger(encrypted, RADIX);
			BigInteger bi_r0 = bi_r1.xor(bi_confuse);

			return new String(bi_r0.toByteArray()); 
		} catch(Exception e) {
			return "";
		}
	}

	private static void printOptions() {
		System.err.println("decr usage:\n");
		System.err.println("  decr <obfuscated>");
		System.err.println();
	}

}