return "", ErrMissingSignTag
	}
	if signFields[1] == "" {
		return "", ErrMissingFields
	}
	signature := signFields[1]
	return signature, ErrNone
}

// Parse slice of signed headers from signed headers tag.
func parseSignedHeader(signedHdrElement string) ([]string, APIErrorCode) {
	signedHdrFields := strings.Split(strings.TrimSpace(signedHdrElement), "=")
	if len(signedHdrFields) != 2 {

     *
     * It helps to consider the real number signif = absX * 2^(SIGNIFICAND_BITS - exponent).
     */
    int shift = exponent - SIGNIFICAND_BITS - 1;
    long twiceSignifFloor = absX.shiftRight(shift).longValue();
    long signifFloor = twiceSignifFloor >> 1;
    signifFloor &= SIGNIFICAND_MASK; // remove the implied bit

    /*
     * We round up if either the fractional part of signif is strictly greater than 0.5 (which is

	}

	if err = claims.UnmarshalJSON(buf[:n]); err != nil {
		return nil, &jwtgo.ValidationError{Inner: err, Errors: jwtgo.ValidationErrorMalformed}
	}

	for _, signer := range hmacSigners {
		if string(alg) == signer.Name {
			return signer, nil
		}
	}

	return nil, jwtgo.NewValidationError(fmt.Sprintf("signing method (%s) is unavailable.", string(alg)),
		jwtgo.ValidationErrorUnverifiable)
}

	hash.Write(data)
	return hash.Sum(nil)
}

// extractSignedHeaders extract signed headers from Authorization header
func extractSignedHeaders(signedHeaders []string, r *http.Request) (http.Header, APIErrorCode) {
	reqHeaders := r.Header
	reqQueries := r.Form
	// find whether "host" is part of list of signed headers.
	// if not return ErrUnsignedHeaders. "host" is mandatory.

	}

	// Since the list of signed headers value contained `expect`, the default value of `100-continue` will be added to extracted signed headers.
	if extractedExpect != expectedExpect {
		t.Errorf("expect header incorrect value: expected `%s`, got `%s`", expectedExpect, extractedExpect)
	}

	// case where the headers don't contain the one of the signed header in the signed headers list.

Beispielsweise verwendet der Google Login OpenID Connect (welches seinerseits OAuth2 verwendet).

Aber der Facebook Login unterstützt OpenID Connect nicht. Es hat seine eigene Variante von OAuth2.

### OpenID (nicht „OpenID Connect“)

Es gab auch eine „OpenID“-Spezifikation. Sie versuchte das Gleiche zu lösen wie **OpenID Connect**, basierte aber nicht auf OAuth2.

 * signed versions of methods for which signedness is an issue.
 *
 * <p>In addition, this class provides several static methods for converting a {@code long} to a
 * {@code String} and a {@code String} to a {@code long} that treat the {@code long} as an unsigned
 * number.
 *
 * <p>Users of these utilities must be <i>extremely careful</i> not to mix up signed and unsigned

		{serverType: "ErasureSD", signer: signerV4},
		// Init and run test on ErasureSD backend, with tls enabled.
		{serverType: "ErasureSD", signer: signerV4, secure: true},
		// Init and run test on Erasure backend.
		{serverType: "Erasure", signer: signerV4},
		// Init and run test on ErasureSet backend.
		{serverType: "ErasureSet", signer: signerV4},
	}
	testCases := []*TestSuiteIAM{}

		}

		// Verify response the V2 signed HTTP request.
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		recV2 := httptest.NewRecorder()
		// construct HTTP request for PUT bucket policy endpoint.

		// verify response for V2 signed HTTP request.

			exit(stopProcess())
		case osSignal := <-globalOSSignalCh:
			logger.Info("Exiting on signal: %s", strings.ToUpper(osSignal.String()))
			daemon.SdNotify(false, daemon.SdNotifyStopping)
			exit(stopProcess())
		case signal := <-globalServiceSignalCh:
			switch signal {
			case serviceRestart:
				logger.Info("Restarting on service signal")
				daemon.SdNotify(false, daemon.SdNotifyReloading)
				stop := stopProcess()