jodd-core/src/main/java/jodd/crypt/PBKDF2Hash.java
private static byte[] fromHex(final String hex) {
		final byte[] binary = new byte[hex.length() / 2];
		for (int i = 0; i < binary.length; i++) {
			binary[i] = (byte) Integer.parseInt(hex.substring(2 * i, 2 * i + 2), 16);
		}
		return binary;
	}
private static byte[] fromHex(final String hex) {
		final byte[] binary = new byte[hex.length() / 2];
		for (int i = 0; i < binary.length; i++) {
			binary[i] = (byte) Integer.parseInt(hex.substring(2 * i, 2 * i + 2), 16);
		}
		return binary;
	}
Converts a string of hexadecimal characters into a byte array.

@param hex the hex string
@return the hex string decoded into a byte array