Signer::getSignature

public function getSignature($value, $salt = null)
{
	if (!is_string($value))
		throw new ArgumentTypeException('value', 'string');

	$key = $this->getKey($salt);
	$signature = $this->algorithm->getSignature($value, $key);
	$signature = $this->encodeSignature($signature);
	return $signature;
}