code: public static byte[] sha1hmac(byte[] key, byte[] text) throws IllegalArgumentException
  	{
  		try
  		{
  			SecretKey sk = new SecretKeySpec(key, "HMACSHA1");
  			Mac m = Mac.getInstance(sk.getAlgorithm());
  			m.init(sk);
  			return m.doFinal(text);
  		}
  		catch (InvalidKeyException e)
  		{
  			throw new IllegalArgumentException(e);
  		}
  		catch (NoSuchAlgorithmException e)
  		{
  			throw new IllegalArgumentException(e);
  		}
  	}
docs: @param key
  @param text
  
  @return
  
  @throws IllegalArgumentException