Airship\Engine\Hail::parseSignedJSON PHP Method

    public function parseSignedJSON(Response $response, SignaturePublicKey $publicKey)
    {
        $code = $response->getStatusCode();
        if ($code >= 200 && $code < 300) {
            $body = (string) $response->getBody();
            $firstNewLine = \strpos($body, "\n");
            // There should be a newline immediately after the base64urlsafe-encoded signature
            if ($firstNewLine !== self::ENCODED_SIGNATURE_LENGTH) {
                throw new SignatureFailed(\sprintf("First newline found at position %s, expected %d.\n%s", \print_r($firstNewLine, true), \print_r(self::ENCODED_SIGNATURE_LENGTH, true), Base64::encode($body)));
            }
            $sig = Base64UrlSafe::decode(Binary::safeSubstr($body, 0, 88));
            $msg = Binary::safeSubstr($body, 89);
            if (!Asymmetric::verify($msg, $publicKey, $sig, true)) {
                throw new SignatureFailed();
            }
            return \Airship\parseJSON($msg, true);
        }
        throw new TransferException();
    }