Tips

SSL Domain Detective

Certificate and domain expiry in one coloured list. Open SSL Domain Detective

• Certificates and domains expire: how to see it coming
  An expired certificate shows visitors a warning, and an expired domain registration can take a site offline. How to keep track of both.
• What is an SSL/TLS certificate, and what does it do?
  An SSL/TLS certificate ties a website's name to a key so browsers can encrypt the connection. What it contains and what it does not prove.
• How do I check when a TLS certificate expires?
  Find a certificate's end date in your browser or with a command-line tool, and see how to read the 'valid to' date.
• What happens when an SSL certificate expires?
  Browsers show a full-page warning, and apps and services may refuse to connect. What visitors see, and what changes once you renew.
• How long is a TLS certificate valid?
  Certificate lifetimes range from weeks to about a year, and the limits have been getting shorter. Why that is, and what it means for renewals.
• SSL vs TLS: what is the difference?
  SSL is the older protocol and TLS is its successor. Why people still say 'SSL certificate' and which one is actually in use.
• What is a certificate authority (CA)?
  A certificate authority signs certificates and is trusted by browsers. How it checks an applicant, and why browsers keep a list of trusted CAs.
• How do I check when a domain registration expires?
  Look up a domain's expiry date with a WHOIS or RDAP lookup or in your registrar account. Some registries do not show it publicly.
• What happens when a domain expires?
  When a registration lapses, the website and email can stop working, and the name may be released. What usually happens, and why the rules vary.
• What is a certificate chain, and why can it break?
  A website certificate links back to a trusted root through intermediate certificates. How the chain works and why a missing link causes errors.
• Certificate name mismatch: what the error means
  A name mismatch error means the certificate does not list the address you opened. The usual causes and what to check.
• Why does automatic certificate renewal fail?
  Automatic renewal usually works, until something around it changes. The common reasons it stops, and how to notice early.
• What is a wildcard certificate?
  A wildcard certificate covers all subdomains at one level, written *.example.com. What it covers, what it does not, and when it is used.
• Registrar, DNS, hosting, certificate: who manages what?
  A domain involves up to four different services, each with its own renewal. What each one does and why expiries get mixed up.
• How do I keep track of expiry dates for many domains?
  A simple method for tracking certificate and domain end dates across several domains: what to record, how often to check and what to colour.

#SSL #TLS #Certificates #DomainExpiry #SysAdmin #MSP #iOS

This page gives general information and is not legal, financial or medical advice. [email protected]