openssl s client -connect

openssl s_client -connect
openssl s_client -connect www.example.com:443 -servername example.com

echo -n | openssl s_client -connect HOST:PORTNUMBER | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /tmp/$SERVERNAME.cert

Examples

openssl s_client -connect www.example.com:443 -servername example.com
CONNECTED(00000006)
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 7 bytes and written 313 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.3
    Cipher    : 0000
    Session-ID: 
    Session-ID-ctx: 
    Master-Key: 
    Start Time: 1707667565
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
---

See also

• openssl, openssl s_client
• openssl [ rand | s_client | passwd | openssl req | openssl rsa | openssl genrsa | openssl x509 | openssl ca | openssl verify | openssl ec | openssl dgst | openssl pkcs12 | openssl asn1parse | openssl help | .cer to .pem, openssl version