@reclaimprotocol/tls/lib/utils/session-ticket.js

TLS 1.2/1.3 for any JavaScript Environment

import { crypto } from "../crypto/index.js";
import { getHash, hkdfExtractAndExpandLabel } from "../utils/decryption-utils.js";
import { SUPPORTED_CIPHER_SUITE_MAP } from "./constants.js";
import { uint8ArrayToDataView } from "./generics.js";
import { expectReadWithLength } from "./packets.js";
export function parseSessionTicket(data) {
    const lifetimeS = read(4).getUint32(0);
    const ticketAgeAddMs = read(4).getUint32(0);
    const nonce = readWLength(1);
    const ticket = readWLength(2);
    const extensions = readWLength(2);
    const sessionTicket = {
        ticket,
        lifetimeS,
        ticketAgeAddMs,
        nonce,
        expiresAt: new Date(Date.now() + lifetimeS * 1000),
        extensions
    };
    return sessionTicket;
    function read(bytes) {
        const result = data.slice(0, bytes);
        data = data.slice(bytes);
        return uint8ArrayToDataView(result);
    }
    function readWLength(bytesLength = 2) {
        const content = expectReadWithLength(data, bytesLength);
        data = data.slice(content.length + bytesLength);
        return content;
    }
}
export async function getPskFromTicket(ticket, { masterKey, hellos, cipherSuite }) {
    const { hashAlgorithm, hashLength } = SUPPORTED_CIPHER_SUITE_MAP[cipherSuite];
    const handshakeHash = await getHash(hellos, cipherSuite);
    const resumeMasterSecret = await hkdfExtractAndExpandLabel(hashAlgorithm, masterKey, 'res master', handshakeHash, hashLength);
    const psk = await hkdfExtractAndExpandLabel(hashAlgorithm, resumeMasterSecret, 'resumption', ticket.nonce, hashLength);
    const emptyHash = await crypto.hash(hashAlgorithm, new Uint8Array());
    const earlySecret = await crypto.extract(hashAlgorithm, hashLength, psk, '');
    const binderKey = await hkdfExtractAndExpandLabel(hashAlgorithm, earlySecret, 'res binder', emptyHash, hashLength);
    // const clientEarlyTrafficSecret = hkdfExtractAndExpandLabel(hashAlgorithm, earlySecret, 'c e traffic', new Uint8Array(), hashLength)
    const finishKey = await hkdfExtractAndExpandLabel(hashAlgorithm, binderKey, 'finished', new Uint8Array(), hashLength);
    const ticketAge = Math.floor(ticket.lifetimeS / 1000 + ticket.ticketAgeAddMs);
    return {
        identity: ticket.ticket,
        ticketAge,
        finishKey: await crypto.importKey(hashAlgorithm, finishKey),
        resumeMasterSecret,
        earlySecret,
        cipherSuite,
    };
}