SAML2\Response\Processor::verifySignature PHP Method

    private function verifySignature(Response $response, IdentityProvider $identityProviderConfiguration)
    {
        if (!$response->isMessageConstructedWithSignature()) {
            $this->logger->info(sprintf('SAMLResponse with id "%s" was not signed at root level, not attempting to verify the signature of the' . ' reponse itself', $response->getId()));
            return;
        }
        $this->logger->info(sprintf('Attempting to verify the signature of SAMLResponse with id "%s"', $response->getId()));
        $this->responseIsSigned = true;
        if (!$this->signatureValidator->hasValidSignature($response, $identityProviderConfiguration)) {
            throw new InvalidResponseException();
        }
    }