return null;
        }

        return newDictionaryFile(encodePath(path), path, timestamp);
    }

    /**
     * Encodes a file path using Base64 URL-safe encoding.
     *
     * @param path the file path to encode
     * @return the Base64 encoded path
     */
    protected String encodePath(final String path) {

	signedHeaders := strings.Join(headers, ";")

	// Get canonical query string.
	req.URL.RawQuery = strings.ReplaceAll(req.URL.Query().Encode(), "+", "%20")

	// Get canonical URI.
	canonicalURI := s3utils.EncodePath(req.URL.Path)

	// Get canonical request.
	// canonicalRequest =
	//  <HTTPMethod>\n
	//  <CanonicalURI>\n
	//  <CanonicalQueryString>\n
	//  <CanonicalHeaders>\n
	//  <SignedHeaders>\n