How do I extract fingerprints from .ssh/known_hosts?

Solution 1:

Try this command:

% ssh-keygen -l -f ~/.ssh/known_hosts

2048 c2:e7:c0:9f:cd:c8:54:88:ac:b3:6b:a6:51:73:2b:e3 mach1,192.168.1.3 (RSA)
2048 a2:5e:8c:4e:2e:be:be:eb:23:12:5e:fe:6c:4b:23:dd mach2,192.168.1.1 (RSA)
1024 ae:5f:bc:e3:33:c3:dd:45:1e:18:1a:46:d1:d6:d2:39 mach3,192.168.1.6 (RSA)
...
...

just want a single host:

% ssh-keygen -l -f ~/.ssh/known_hosts -F mach1
2048 c2:e7:c0:9f:cd:c8:54:88:ac:b3:6b:a6:51:73:2b:e3 mach1 (RSA)

Resources

http://www.gossamer-threads.com/lists/openssh/users/49503