Function readWebBundlePayloadLength

go/integrityblock/integrityblock.go:113–127

readWebBundlePayloadLength returns the length of the web bundle parsed from the last 8 bytes of the web bundle file. [Web Bundle's Trailing Length]: https://wpack-wg.github.io/bundled-responses/draft-ietf-wpack-bundled-responses.html#name-trailing-length

(bundleFile *os.File)

// readWebBundlePayloadLength returns the length of the web bundle parsed from the last 8 bytes of the web bundle file.
// [Web Bundle's Trailing Length]: https://wpack-wg.github.io/bundled-responses/draft-ietf-wpack-bundled-responses.html#name-trailing-length
func readWebBundlePayloadLength(bundleFile *os.File) (int64, error) {
	// Finds the offset, from which the 8 bytes containing the web bundle length start.
	_, err := bundleFile.Seek(-8, io.SeekEnd)
	if err != nil {
		return 0, err
	}

	// Reads from the offset to the end of the file (those 8 bytes).
	webBundleLengthBytes, err := ioutil.ReadAll(bundleFile)
	if err != nil {
		return 0, err
	}

	return int64(binary.BigEndian.Uint64(webBundleLengthBytes)), nil
}

// obtainIntegrityBlock returns either the existing integrity block parsed (not supported in v1) or a newly
// created empty integrity block. Integrity block preceeds the actual web bundle bytes. The second return