Get certificate fingerprint of HTTPS server from command line?

Question

Recently Mercurial has added certificate validation when connecting to HTTPS servers. I\'m trying to clone the wiki repository for a googlecode project at https://wiki

Answer 1

The page at http://wiki.debuntu.org/wiki/OpenSSL#Retrieving_certificate_informations lists the command lines for that (and printing out the relevant information). From that page and some of the man pages, it seems like what you want is (for bash):

openssl s_client -connect : < /dev/null 2>/dev/null | openssl x509 -fingerprint -noout -in /dev/stdin

If you want the whole certificate, leave off the | symbol and everything after it.