async initialize()

in src/states.js [368:401]

• 15 lines of code
• 1 McCabe index (conditional complexity)

  async initialize(sessionId, pskIndex) {
    await this.conn._sendHandshakeMessage(new ServerHello(
      // Server random
      await getRandomBytes(32),
      sessionId,
      [
        new SupportedVersionsExtension(null, VERSION_TLS_1_3),
        new PreSharedKeyExtension(null, null, pskIndex),
      ]
    ));
    // If the client sent a non-empty sessionId, the server *must* send a change-cipher-spec for b/w compat.
    if (sessionId.byteLength > 0) {
      await this.conn._sendChangeCipherSpec();
    }
    // We can now transition to the encrypted part of the handshake.
    const keyschedule = this.conn._keyschedule;
    await keyschedule.addECDHE(null);
    await this.conn._setSendKey(keyschedule.serverHandshakeTrafficSecret);
    await this.conn._setRecvKey(keyschedule.clientHandshakeTrafficSecret);
    // Send an empty EncryptedExtensions message.
    await this.conn._sendHandshakeMessage(new EncryptedExtensions([]));
    // Send the Finished message.
    const serverFinishedMAC = await keyschedule.calculateFinishedMAC(keyschedule.serverHandshakeTrafficSecret);
    await this.conn._sendHandshakeMessage(new Finished(serverFinishedMAC));
    // We can now *send* using the application traffic key,
    // but have to wait to receive the client Finished before receiving under that key.
    // We need to remember the handshake state from before the client Finished
    // in order to successfully verify the client Finished.
    const clientFinishedTranscript = await keyschedule.getTranscript();
    const clientHandshakeTrafficSecret = keyschedule.clientHandshakeTrafficSecret;
    await keyschedule.finalize();
    await this.conn._setSendKey(keyschedule.serverApplicationTrafficSecret);
    await this.conn._transition(SERVER_WAIT_FINISHED, clientHandshakeTrafficSecret, clientFinishedTranscript);
  }