spacebar/webrtc/src/opcodes/SelectProtocol.ts

import { WebSocket } from "@fosscord/gateway";
import { Payload } from "./index";
import { VoiceOPCodes } from "@fosscord/util";
import { Server } from "../Server";
import * as mediasoup from "mediasoup";
import { RtpCodecCapability } from "mediasoup/node/lib/RtpParameters";
import * as sdpTransform from 'sdp-transform';
import sodium from "libsodium-wrappers";

export interface CodecPayload {
	name: string,
	type: "audio" | "video",
	priority: number,
	payload_type: number,
	rtx_payload_type: number | null,
}

export interface SelectProtocolPayload extends Payload {
	d: {
		codecs: Array<CodecPayload>,
		data: string,	// SDP if webrtc
		protocol: string,
		rtc_connection_id: string,
		sdp?: string,	// same as data
	};
}

/*

	Sent by client:
{
	"op": 1,
	"d": {
		"protocol": "webrtc",
		"data": "
			a=extmap-allow-mixed
			a=ice-ufrag:vNxb
			a=ice-pwd:tZvpbVPYEKcnW0gGRPq0OOnh
			a=ice-options:trickle
			a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
			a=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
			a=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
			a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid
			a=rtpmap:111 opus/48000/2
			a=extmap:14 urn:ietf:params:rtp-hdrext:toffset
			a=extmap:13 urn:3gpp:video-orientation
			a=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay
			a=extmap:6 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type
			a=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing
			a=extmap:8 http://www.webrtc.org/experiments/rtp-hdrext/color-space
			a=extmap:10 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
			a=extmap:11 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
			a=rtpmap:96 VP8/90000
			a=rtpmap:97 rtx/90000
		",
		"codecs": [
			{
				"name": "opus",
				"type": "audio",
				"priority": 1000,
				"payload_type": 111,
				"rtx_payload_type": null
			},
			{
				"name": "H264",
				"type": "video",
				"priority": 1000,
				"payload_type": 102,
				"rtx_payload_type": 121
			},
			{
				"name": "VP8",
				"type": "video",
				"priority": 2000,
				"payload_type": 96,
				"rtx_payload_type": 97
			},
			{
				"name": "VP9",
				"type": "video",
				"priority": 3000,
				"payload_type": 98,
				"rtx_payload_type": 99
			}
		],
		"rtc_connection_id": "3faa0b80-b3e2-4bae-b291-273801fbb7ab"
	}
}
*/

export async function onSelectProtocol(this: Server, socket: WebSocket, data: Payload) {
	if (data.d.sdp) {
		const rtpCapabilities = this.mediasoupRouters[0].rtpCapabilities;
		const codecs = rtpCapabilities.codecs as RtpCodecCapability[];

		const transport = this.mediasoupTransports[0];	//whatever

		const res = sdpTransform.parse(data.d.sdp);

		const videoCodec = this.mediasoupRouters[0].rtpCapabilities.codecs!.find((x: any) => x.kind === "video");
		const audioCodec = this.mediasoupRouters[0].rtpCapabilities.codecs!.find((x: any) => x.kind === "audio");

		const producer = this.mediasoupProducers[0] || await transport.produce({
			kind: "audio",
			rtpParameters: {
				mid: "audio",
				codecs: [{
					clockRate: audioCodec!.clockRate,
					payloadType: audioCodec!.preferredPayloadType as number,
					mimeType: audioCodec!.mimeType,
					channels: audioCodec?.channels,
				}],
				headerExtensions: res.ext?.map(x => ({
					id: x.value,
					uri: x.uri,
				})),
			},
			paused: false,
		});

		console.log("can consume: " + this.mediasoupRouters[0].canConsume({ producerId: producer.id, rtpCapabilities: rtpCapabilities }));

		const consumer = this.mediasoupConsumers[0] || await transport.consume({
			producerId: producer.id,
			paused: false,
			rtpCapabilities,
		});

		transport.connect({
			dtlsParameters: {
				fingerprints: transport.dtlsParameters.fingerprints,
				role: "server",
			}
		});

		socket.send(JSON.stringify({
			op: VoiceOPCodes.SESSION_DESCRIPTION,
			d: {
				video_codec: videoCodec?.mimeType?.substring(6) || undefined,
				// mode: "xsalsa20_poly1305_lite",
				media_session_id: transport.id,
				audio_codec: audioCodec?.mimeType.substring(6),
				secret_key: sodium.from_hex("724b092810ec86d7e35c9d067702b31ef90bc43a7b598626749914d6a3e033ed").buffer,
				sdp: `m=audio ${50001} ICE/SDP\n`
					+ `a=fingerprint:sha-256 ${transport.dtlsParameters.fingerprints.find(x => x.algorithm === "sha-256")?.value}\n`
					+ `c=IN IP4 ${transport.iceCandidates[0].ip}\n`
					+ `t=0 0\n`
					+ `a=ice-lite\n`
					+ `a=rtcp-mux\n`
					+ `a=rtcp:${50001}\n`
					+ `a=ice-ufrag:${transport.iceParameters.usernameFragment}\n`
					+ `a=ice-pwd:${transport.iceParameters.password}\n`
					+ `a=fingerprint:sha-256 ${transport.dtlsParameters.fingerprints.find(x => x.algorithm === "sha-256")?.value}\n`
					+ `a=candidate:1 1 ${transport.iceCandidates[0].protocol.toUpperCase()} ${transport.iceCandidates[0].priority} ${transport.iceCandidates[0].ip} ${50001} typ ${transport.iceCandidates[0].type}`
			}
		}));
		return;
	}
	else {
		/*
			{
				"video_codec":"H264",
				"sdp":
				"
					m=audio 50010 ICE/SDP
					a=fingerprint:sha-256 4A:79:94:16:44:3F:BD:05:41:5A:C7:20:F3:12:54:70:00:73:5D:33:00:2D:2C:80:9B:39:E1:9F:2D:A7:49:87
					c=IN IP4 109.200.214.158
					a=rtcp:50010
					a=ice-ufrag:+npq
					a=ice-pwd:+jf7jAesMeHHby43FRqWTy
					a=fingerprint:sha-256 4A:79:94:16:44:3F:BD:05:41:5A:C7:20:F3:12:54:70:00:73:5D:33:00:2D:2C:80:9B:39:E1:9F:2D:A7:49:87
					a=candidate:1 1 UDP 4261412862 109.200.214.158 50010 typ host",
					"media_session_id":"59265c94fa13e313492c372c4c8da801
				",
				"audio_codec":"opus"
			}
		*/


		/*
			{
				"video_codec": "H264",
				"secret_key": [36, 80, 96, 53, 95, 149, 253, 16, 137, 186, 238, 222, 251, 180, 94, 150, 112, 137, 192, 109, 69, 79, 218, 111, 217, 197, 56, 74, 18, 41, 51, 140],
				"mode": "aead_aes256_gcm_rtpsize",
				"media_session_id": "797575a97a87b63e81e2399348b97ad1",
				"audio_codec": "opus"
			};
		*/

		this.decryptKey = sodium.randombytes_buf(sodium.crypto_secretbox_KEYBYTES);

		// this.decryptKey = new Array(sodium.crypto_secretbox_KEYBYTES).fill(null).map((x, i) => i + 1);
		console.log(this.decryptKey);

		socket.send(JSON.stringify({
			op: VoiceOPCodes.SESSION_DESCRIPTION,
			d: {
				video_codec: "H264",
				secret_key: [...this.decryptKey.values()],
				mode: "aead_aes256_gcm_rtpsize",
				media_session_id: "blah blah blah",
				audio_codec: "opus",
			}
		}));
	}
}