WooYun.org

public class MainActivity extends ActionBarActivity {
	private TextView signatureTxt;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		signatureTxt = (TextView)findViewById(R.id.signature);
		String result = "";
		try {
			String signature = this.getPackageManager().getPackageInfo(this.getPackageName(), 64).signatures[0].toCharsString();
			MessageDigest msgDigest = MessageDigest.getInstance("MD5");
			byte[] arrayOfByte;
			StringBuffer localStringBuffer;
			int i;
			try {
				msgDigest.reset();
				msgDigest.update(signature.getBytes("UTF-8"));
			} catch (UnsupportedEncodingException unsupportedencodingexception) {
				unsupportedencodingexception.printStackTrace();
			}
			arrayOfByte = msgDigest.digest();
			localStringBuffer = new StringBuffer();
			i = 0;
			do {
				if (i >= arrayOfByte.length) {
					result = localStringBuffer.toString();
					break;
				}
				if (Integer.toHexString(0xff & arrayOfByte[i]).length() == 1) {
					localStringBuffer.append("0").append(
							Integer.toHexString(0xff & arrayOfByte[i]));
				} else {
					localStringBuffer.append(Integer
							.toHexString(0xff & arrayOfByte[i]));
				}
				i++;
			} while (true);
		} catch (NameNotFoundException e) {
			e.printStackTrace();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		signatureTxt.setText(result);
		Log.i("Signature", result + "");
	}
}