async recvHandshakeMessage()

in src/states.js [241:263]

• 22 lines of code
• 6 McCabe index (conditional complexity)

  async recvHandshakeMessage(msg) {
    if (! (msg instanceof ServerHello)) {
      throw new TLSError(ALERT_DESCRIPTION.UNEXPECTED_MESSAGE);
    }
    if (! bytesAreEqual(msg.sessionId, this._sessionId)) {
      throw new TLSError(ALERT_DESCRIPTION.ILLEGAL_PARAMETER);
    }
    const pskExt = msg.extensions.get(EXTENSION_TYPE.PRE_SHARED_KEY);
    if (! pskExt) {
      throw new TLSError(ALERT_DESCRIPTION.MISSING_EXTENSION);
    }
    // We expect only the SUPPORTED_VERSIONS and PRE_SHARED_KEY extensions.
    if (msg.extensions.size !== 2) {
      throw new TLSError(ALERT_DESCRIPTION.UNSUPPORTED_EXTENSION);
    }
    if (pskExt.selectedIdentity !== 0) {
      throw new TLSError(ALERT_DESCRIPTION.ILLEGAL_PARAMETER);
    }
    await this.conn._keyschedule.addECDHE(null);
    await this.conn._setSendKey(this.conn._keyschedule.clientHandshakeTrafficSecret);
    await this.conn._setRecvKey(this.conn._keyschedule.serverHandshakeTrafficSecret);
    await this.conn._transition(CLIENT_WAIT_EE);
  }