102 lines
3.4 KiB
TypeScript
102 lines
3.4 KiB
TypeScript
import { chacha20 } from "@noble/ciphers/chacha";
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type KeyInput = Buffer | Uint8Array;
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const senderAttached = new WeakSet<RTCRtpSender>();
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const receiverAttached = new WeakSet<RTCRtpReceiver>();
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function toUint8Array(input: KeyInput): Uint8Array {
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const u8 = input instanceof Uint8Array ? input : new Uint8Array(input);
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return new Uint8Array(u8.slice().buffer);
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}
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function buildNonce(timestamp: unknown): Uint8Array {
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const nonce = new Uint8Array(12);
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const ts = typeof timestamp === "number"
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? timestamp
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: typeof timestamp === "bigint"
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? Number(timestamp)
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: 0;
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new DataView(nonce.buffer).setUint32(8, ts >>> 0, false);
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return nonce;
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}
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function processFrame(data: ArrayBuffer, key: Uint8Array, timestamp: unknown): ArrayBuffer {
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const nonce = buildNonce(timestamp);
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const input = new Uint8Array(data);
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// ChaCha20 симметричный: encrypt === decrypt, тот же размер
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const output = chacha20(key, nonce, input);
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return output.buffer as ArrayBuffer;
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}
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export async function attachSenderE2EE(sender: RTCRtpSender, keyInput: KeyInput): Promise<void> {
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if (senderAttached.has(sender)) {
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return;
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}
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senderAttached.add(sender);
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const key = toUint8Array(keyInput);
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if (key.byteLength !== 32) {
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throw new Error(`E2EE key must be 32 bytes, got ${key.byteLength}`);
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}
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const anySender = sender as any;
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if (!anySender.createEncodedStreams) {
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throw new Error("createEncodedStreams is not available on RTCRtpSender");
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}
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const { readable, writable } = anySender.createEncodedStreams();
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const enc = new TransformStream<any, any>({
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// Синхронный transform — нет async, нет накопления очереди
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transform(frame, controller) {
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try {
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frame.data = processFrame(frame.data, key, frame.timestamp);
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controller.enqueue(frame);
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} catch (e) {
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console.error("Sender E2EE frame failed:", e);
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controller.enqueue(frame);
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}
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}
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});
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readable.pipeThrough(enc).pipeTo(writable).catch((e) => {
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console.error("Sender E2EE pipeline failed:", e);
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});
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}
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export async function attachReceiverE2EE(receiver: RTCRtpReceiver, keyInput: KeyInput): Promise<void> {
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if (receiverAttached.has(receiver)) {
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return;
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}
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receiverAttached.add(receiver);
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const key = toUint8Array(keyInput);
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if (key.byteLength !== 32) {
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throw new Error(`E2EE key must be 32 bytes, got ${key.byteLength}`);
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}
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const anyReceiver = receiver as any;
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if (!anyReceiver.createEncodedStreams) {
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throw new Error("createEncodedStreams is not available on RTCRtpReceiver");
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}
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const { readable, writable } = anyReceiver.createEncodedStreams();
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const dec = new TransformStream<any, any>({
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// Синхронный transform — нет async, нет накопления очереди
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transform(frame, controller) {
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try {
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frame.data = processFrame(frame.data, key, frame.timestamp);
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controller.enqueue(frame);
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} catch (e) {
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console.error("Receiver E2EE frame failed:", e);
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controller.enqueue(frame);
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}
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}
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});
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readable.pipeThrough(dec).pipeTo(writable).catch((e) => {
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console.error("Receiver E2EE pipeline failed:", e);
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});
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} |