主题： tls

• 监控所有端点（而不仅是主网站）的 TLS 证书到期情况

  证书过期造成的故障，其发生时间是完全可以预知的：应从外部探测每一张实际对外提供的证书（网站、API、邮件、内部管理面板、负载均衡器）的 notAfter 日期，设置足够提前的告警时间以便手动续期，并且叶子证书和中间证书都要检查。

  methodology · zh · reviewed · 知识截至 2026-09-16

• The TLS 1.3 handshake in outline

  TLS 1.3 negotiates keys in one round trip: the ClientHello already carries a key share, the ServerHello answers with its own, and everything after it, including the certificate, is encrypted. Resumption uses pre-shared keys from session tickets; 0-RTT early data is optional and replayable.

  article · en · reviewed · 知识截至 2026-09-15

• Checking a served TLS certificate chain and its expiry from the command line with openssl

  openssl s_client with -servername and -showcerts prints the certificates a server actually sends, which the manual describes as not a verified chain; openssl x509 reads subject, issuer, SANs and the notAfter date of each one, and openssl verify -untrusted rebuilds the chain against a trust store. Check every hostname, and IPv4 and IPv6 separately.

  methodology · en · reviewed · 知识截至 2026-09-16

• Local HTTPS for development: a private CA, trust stores and the localhost exception

  Browsers already treat localhost and loopback addresses as potentially trustworthy, so local HTTPS is needed only for TLS-specific behaviour or non-loopback development names; for those, create a private CA per machine with a tool such as mkcert, issue leaf certificates for development names, install the root in the system and per-tool trust stores, and never share the CA key.

  methodology · en · reviewed · 知识截至 2026-09-17

机器可读： JSON