CSR Racing hack

Sign.java

/**
	Using iExplorer, navigate to CSR Racing and extract the file from
	/Library/Caches/pp.

	$ mv user85500672{,.gz}
	$ gunzip user85500672.gz
	$ edit user85500672

	Remove the signature (first line). Edit "caea", "casp", "goea", and "gosp"
	to modify your cash earned, cash spent, gold earned, and gold spent
	respectively. Leave the NULL at the end of the file.

	$ java Sign user85500672

	Add the new signature back to the beginning of the file.

	$ gzip user85500672
	$ mv user85500672{.gz,}

	Move the user file back onto your device.

	Derived from the csrProfileFix tool originally posted here:
		http://www.sinfuliphone.com/showthread.php?t=10024300
*/

import java.io.*;
import javax.crypto.*;
import javax.crypto.spec.*;

public class Sign {

	public static void main(String args[]) throws Exception {

		FileInputStream fis = new FileInputStream(args[0]);
		byte[] data = new byte[fis.available()];
		fis.read(data);

		int dataLength = data.length;
		while (data[dataLength - 1] == 0) { // ignore tailing null characters
			dataLength--;
		}

		byte[] secretKeyBytes = { 69, 89, 73, 118, 81, 73, 118, 107 };
		SecretKeySpec secretKey = new SecretKeySpec(secretKeyBytes, "HmacSHA1");
		Mac mac = Mac.getInstance("HmacSHA1");
		mac.init(secretKey);
		mac.update(data, 0, dataLength);
		byte[] digest = mac.doFinal();

		String finalData = String.format("%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x", new Object[] { 
			Integer.valueOf(digest[0]  & 0xFF), Integer.valueOf(digest[1]  & 0xFF),
			Integer.valueOf(digest[2]  & 0xFF), Integer.valueOf(digest[3]  & 0xFF),
			Integer.valueOf(digest[4]  & 0xFF), Integer.valueOf(digest[5]  & 0xFF),
			Integer.valueOf(digest[6]  & 0xFF), Integer.valueOf(digest[7]  & 0xFF),
			Integer.valueOf(digest[8]  & 0xFF), Integer.valueOf(digest[9]  & 0xFF), 
			Integer.valueOf(digest[10] & 0xFF), Integer.valueOf(digest[11] & 0xFF),
			Integer.valueOf(digest[12] & 0xFF), Integer.valueOf(digest[13] & 0xFF),
			Integer.valueOf(digest[14] & 0xFF), Integer.valueOf(digest[15] & 0xFF),
			Integer.valueOf(digest[16] & 0xFF), Integer.valueOf(digest[17] & 0xFF),
			Integer.valueOf(digest[18] & 0xFF), Integer.valueOf(digest[19] & 0xFF)
		});

		System.out.println(finalData);
	}

}