openssl s_client

all

Create TLS client connections.

Examples (4)

Display the start and expiry dates for a domain's certificate

openssl s_client -connect host:port 2>/dev/null | openssl x509 -noout -dates

Display the certificate presented by an SSL/TLS server

openssl < /dev/null s_client -connect host:port

Set the Server Name Indicator (SNI) when connecting to the SSL/TLS server

openssl s_client -connect host:port -servername hostname

Display the complete certificate chain of an HTTPS server

openssl < /dev/null s_client -connect host:443 -showcerts