How do I check if my SSL Certificate is SHA1 or SHA2 on the commandline

Question

How do I check if my SSL Certificate is using SHA1 or SHA2, from the commandline?

And yes, i this is similar to this, but i need a cli-tool and i want to understand how it is done.

Solution 1

after googling for quite some time i came up with the following snippet (unix):

openssl s_client -connect <host>:<port> < /dev/null 2>/dev/null | openssl x509 -text -in /dev/stdin | grep "Signature Algorithm"

windows (thanx Nick Westgate, see below)

certutil -dump cacert.pem | find "Algorithm"

Solution 2

I know the topic is old but I think

openssl x509 -in yourcert.crt -text -noout | grep "Signature Algorithm"

would be an easier solution.

Solution 3

You didn't specify a platform, but in a Windows command prompt you can use:

certutil -dump cacert.pem | find "Algorithm"

Comments

[Shalom Carmel]

This is exactly what the first answer eventually does. A certificate is usually installed on a web server and does not exist in a file, and rink.attendant.6's answer fetches the cerificate AND runs the verification check in a single line

[that guy from over there]

included your answer, thanx

[Doktor J]

@ShalomCarmel but this one is helpful to admins like myself who want to double-check a certificate we've inherited, and have shell access to the server :)

[Björn]

In my case on Windows with a .p12-certificate i used: certutil -dump crtname.p12 | find "Cert Hash" (Also, my certificate had a password, so I had to type that in too after pressing enter.)