Revoking certain certificates on March 4

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The online tool seems only to support checking HTTPS on port 443.

For other services, the suggested openssl s_client command, modified as appropriate, can be used. Here are some examples:

  • openssl s_client -connect example.com:25 -servername example.com -starttls smtp -showcerts </dev/null 2>/dev/null | openssl x509 -text -noout | grep -A 1 Serial\ Number | tr -d :

  • openssl s_client -connect example.com:587 -servername example.com -starttls smtp -showcerts </dev/null 2>/dev/null | openssl x509 -text -noout | grep -A 1 Serial\ Number | tr -d :

  • openssl s_client -connect example.com:143 -servername example.com -starttls imap -showcerts </dev/null 2>/dev/null | openssl x509 -text -noout | grep -A 1 Serial\ Number | tr -d :

  • openssl s_client -connect example.com:993 -servername example.com -showcerts </dev/null 2>/dev/null | openssl x509 -text -noout | grep -A 1 Serial\ Number | tr -d :

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