89 lines
3.4 KiB
TypeScript
89 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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/**
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* Переиспользуемый процессор фреймов.
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* Один экземпляр на sender/receiver — нет аллокаций на каждый фрейм.
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*/
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function createFrameProcessor(key: Uint8Array) {
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// Переиспользуемые буферы — не создаём новые на каждый фрейм
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const nonce = new Uint8Array(12);
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const nonceView = new DataView(nonce.buffer);
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return function processFrame(data: ArrayBuffer): ArrayBuffer {
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// Переиспользуем nonce буфер
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nonce.fill(0);
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nonceView.setUint32(8, (data.byteLength ^ (data.byteLength << 8)) >>> 0, false);
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const input = new Uint8Array(data);
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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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}
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function createTransform(processFrame: (data: ArrayBuffer) => ArrayBuffer) {
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return new TransformStream<any, any>({
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transform(frame, controller) {
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try {
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const start = performance.now();
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frame.data = processFrame(frame.data);
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const elapsed = performance.now() - start;
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if (elapsed > 1) {
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console.warn(`E2EE slow frame: ${elapsed.toFixed(2)}ms`);
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}
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controller.enqueue(frame);
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} catch (e) {
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// не рвём поток — пропускаем фрейм как есть
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console.error("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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}
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export async function attachSenderE2EE(sender: RTCRtpSender, keyInput: KeyInput): Promise<void> {
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if (senderAttached.has(sender)) return;
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senderAttached.add(sender);
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const key = toUint8Array(keyInput);
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if (key.byteLength !== 32) throw new Error(`E2EE key must be 32 bytes, got ${key.byteLength}`);
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const anySender = sender as any;
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if (!anySender.createEncodedStreams) throw new Error("createEncodedStreams not available on RTCRtpSender");
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const { readable, writable } = anySender.createEncodedStreams();
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const processFrame = createFrameProcessor(key);
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readable
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.pipeThrough(createTransform(processFrame))
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.pipeTo(writable)
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.catch((e) => console.error("Sender E2EE pipeline failed:", e));
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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)) return;
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receiverAttached.add(receiver);
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const key = toUint8Array(keyInput);
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if (key.byteLength !== 32) throw new Error(`E2EE key must be 32 bytes, got ${key.byteLength}`);
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const anyReceiver = receiver as any;
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if (!anyReceiver.createEncodedStreams) throw new Error("createEncodedStreams not available on RTCRtpReceiver");
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const { readable, writable } = anyReceiver.createEncodedStreams();
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const processFrame = createFrameProcessor(key);
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readable
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.pipeThrough(createTransform(processFrame))
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.pipeTo(writable)
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.catch((e) => console.error("Receiver E2EE pipeline failed:", e));
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} |