OpenSSL Certificate Check
https://rbwilson.ca/how-to-verify-certificates-with-openssl/ Linux echo | openssl s_client -connect news.grc.com:563 | openssl x509 -text -noout Windows: openssl s_client -connect outlook.office365.com:443 openssl s_client -connect contoso-com.mail.protection.outlook.com:25 -starttls smtp | |
Search Keywords: SSL/TLS Certificates, Verify + Validate |