SSL : How to check if current certificate is sha1 or sha2 from command line

Problem :

You want to check if a website SSL certificate is sha1 or sha2 algorithm from command line.

Solution :

Assuming your are running a *nix based OS like OSX or Linux with OpenSSL installed.

This is the openssl command to check your website certificate from the command line :

> openssl s_client -connect www.yoursite.com:443 < /dev/null 2>/dev/null | openssl x509 -text -in /dev/stdin | grep "Signature Algorithm"

the result should look like

Signature Algorithm: sha1WithRSAEncryption for sha1

and

Signature Algorithm: sha256WithRSAEncryption for sha2