zefie/minisrv
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

document PNM server a bit (but I'm tired)

Browse Source
This commit is contained in:
zefie
2026-04-21 19:34:08 -04:00
parent 90425aaf33
commit 2b28a403a0
1 changed files with 12 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
zefie_wtvp_minisrv/includes/classes/WTVPNM.js
View File

@@ -1,11 +1,20 @@
// Pure JS implementation of old Progressive Networks PNM streaming protocol used by WebTV and RealPlayer 8.
// This server only supports UDP streams, so mplayer (and others that are TCP only) will not work
// It does support seeking and pausing via the TCP control channel, but does not support bitrate switching or any of the
// other advanced features of the RealServer protocol. It should be compatible with WebTV 2.5 and RP8 clients, but has only been tested with RP8.
// other advanced features of the RealServer protocol. It should be compatible with WebTV 2.5 and RP8 clients.
// RealAudio 3, RealAudio 5, RealAudio G2 and RealAudio 8 (not WebTV compatible) files.
// It is also not compatible with live streams at this time.
// Also not tested with SureStream since they never worked with WebTV. (could we, as the server, make SureStream work with WebTV?)
// How it works (roughly):
// The client sends a md5 challenge in the initial request with the filename, and the current timestamp.
// The current timestamp (sent by the client) is parsed into epoch, then XORed with 0x67E32B93 to form "v12"
// The server then generates a challenge response with this value and the client challenge. (this is "initMD5")
// The server then generates a second hash based on the server challenge (random, but small for WebTV, large for RP8) and the request filename, XORed with "initMD5" (this is "resp1").
// The server sends resp1+initMD5 as a large 64-byte challenge
// The client validates this challenge by calculating the server challenge and its own client challenge to produce a final hash, which it sends back to the server.
// If the hash matches, the client is authenticated and the server starts sending UDP packets.
const net = require('net');
const fs = require('fs');
const path = require('path');
@@ -585,19 +594,8 @@ class WTVPNM {
sendHelloSequence(socket, session) {
if (!socket || !session || session.helloSent) return;
// RealServer sends the 9-byte PNA hello first, then WAITS for the
// client to ACK it before sending the 361-byte descriptor (observed
// ~85ms gap in wtv_multi.pcap). When we send both back-to-back,
// WebTV silently disconnects after the hello and RP8 gets stuck
// buffering at 0kbps — both clients parse hello and descriptor in
// separate states and dislike receiving the descriptor bytes before
// the hello-handling state completes.
//
// Node's 'net' socket doesn't expose per-write ACK callbacks, but a
// short timer approximates the real flow well enough: send hello,
// then send descriptor ~100ms later (> typical delayed-ACK of 40ms
// but < client timeout). The gap also gives the client time to
// parse the challenge before the next packet arrives.
// RealServer sends the 9-byte PNA hello first, then sends the
// descriptor to the client a several milliseconds later
const hello = this.buildPnaHello(session);
session.helloSent = true;
this.send(socket, hello);