// Session tokens are not allowed in STS AssumeRole requests.
	if getSessionToken(r) != "" {
		return auth.Credentials{}, ErrAccessDenied
	}

	return user, ErrNone
}

func parseForm(r *http.Request) error {
	if err := r.ParseForm(); err != nil {
		return err
	}
	for k, v := range r.PostForm {
		if _, ok := r.Form[k]; !ok {
			r.Form[k] = v
		}
	}
	return nil
}

		}

		// Do the same for the headers.
		for key, value := range testCase.headers {
			req.Header.Set(key, value)
		}

		// parse form.
		req.ParseForm()

		// Check if it matches!
		err := doesPresignedSignatureMatch(payloadSHA256, req, testCase.region, serviceS3)
		if err != testCase.expected {

func (s *storageRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool {
	if !s.IsAuthValid(w, r) {
		return false
	}

	if err := r.ParseForm(); err != nil {
		s.writeErrorResponse(w, err)
		return false
	}

	diskID := r.Form.Get(storageRESTDiskID)
	if diskID == "" {
		// Request sent empty disk-id, we allow the request