'keylog' 事件

• line <Buffer> ASCII 文本行，采用 NSS SSLKEYLOGFILE 格式。
• tlsSocket <tls.TLSSocket> 生成它的 tls.TLSSocket 实例。

keylog 事件在生成或通过与此服务器的连接接收密钥材料时触发（通常在握手完成之前，但不一定）。 该密钥材料可以存储用于调试，因为它允许对捕获的 TLS 流量进行解密。 它可以为每个套接字多次触发。

一个典型的用例是将接收到的行附加到公共文本文件中，稍后软件（例如 Wireshark）使用它来解密流量：

const logFile = fs.createWriteStream('/tmp/ssl-keys.log', { flags: 'a' });
// ...
server.on('keylog', (line, tlsSocket) => {
  if (tlsSocket.remoteAddress !== '...')
    return; // 仅记录特定 IP 的密钥
  logFile.write(line);
});

• line <Buffer> Line of ASCII text, in NSS SSLKEYLOGFILE format.
• tlsSocket <tls.TLSSocket> The tls.TLSSocket instance on which it was generated.

The keylog event is emitted when key material is generated or received by a connection to this server (typically before handshake has completed, but not necessarily). This keying material can be stored for debugging, as it allows captured TLS traffic to be decrypted. It may be emitted multiple times for each socket.

A typical use case is to append received lines to a common text file, which is later used by software (such as Wireshark) to decrypt the traffic:

const logFile = fs.createWriteStream('/tmp/ssl-keys.log', { flags: 'a' });
// ...
server.on('keylog', (line, tlsSocket) => {
  if (tlsSocket.remoteAddress !== '...')
    return; // Only log keys for a particular IP
  logFile.write(line);
});