Skip to content

Instantly share code, notes, and snippets.

@tuxfight3r

tuxfight3r/ssh-keygen

Last active February 27, 2025 17:34
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save tuxfight3r/b92ad1450067bf4336ee to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save tuxfight3r/b92ad1450067bf4336ee to your computer and use it in GitHub Desktop.
Download ZIP

Revisions

  1. tuxfight3r revised this gist Jan 27, 2015. 1 changed file with 22 additions and 1 deletion.
    23 changes: 22 additions & 1 deletion ssh-keygen
    View file
    Original file line number Diff line number Diff line change
    @@ -1,4 +1,4 @@
    #Read keys from an authorized_keys file and print the finger print
    #Read multiple keys from an authorized_keys file and print the finger print

    [root@server01 .ssh]# while read line; do ssh-keygen -l -f /dev/stdin <<< $line; done < authorized_keys
    2048 87:7a:4d:70:d2:10:a4:4b:b7:e1:2b:7c:77:92:25:04 /dev/stdin (RSA)
    @@ -35,4 +35,25 @@ ssh-copy-id -i .ssh/id_rsa.pub user@remote_host:
    #Easy known hosts file management
    ssh-keygen -R remote-host

    ##Verify private/public OpenSSH Keys
    #public key verification
    [-0-(mohan@linuxbox):~]$ssh-keygen -l -f test_ssh_key.pub
    2048 cc:95:23:50:91:f5:38:73:b5:e7:69:fe:bc:53:c6:b1 mohan@linuxbox (RSA)

    #private key verification
    [-0-(mohan@linuxbox):~]$eval $(ssh-agent)
    Agent pid 32377
    [-0-(mohan@linuxbox):~]$ssh-add test_ssh_key
    Identity added: test_ssh_key (test_ssh_key)
    [-255-(mohan@linuxbox):~]$ssh-add -l
    2048 cc:95:23:50:91:f5:38:73:b5:e7:69:fe:bc:53:c6:b1 test_ssh_key (RSA)

    or
    #regenerate publickey from private key and verify its finger print.
    [-0-(mohan@linuxbox):~]$ssh-keygen -l -f /dev/stdin <<< $(ssh-keygen -y -f test_ssh_key)
    2048 cc:95:23:50:91:f5:38:73:b5:e7:69:fe:bc:53:c6:b1 /dev/stdin (RSA)

    #setup ssh agent - lifetime can be h - hours, m - minutes, s-seconds
    echo 'eval $(ssh-agent -t 3h)' >> ~/.bash_profile
    ssh-add ~/.ssh/
    ssh-add -l
  2. tuxfight3r created this gist Jan 20, 2015.
    38 changes: 38 additions & 0 deletions ssh-keygen
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,38 @@
    #Read keys from an authorized_keys file and print the finger print

    [root@server01 .ssh]# while read line; do ssh-keygen -l -f /dev/stdin <<< $line; done < authorized_keys
    2048 87:7a:4d:70:d2:10:a4:4b:b7:e1:2b:7c:77:92:25:04 /dev/stdin (RSA)
    2048 7d:f0:89:94:00:09:bc:70:46:59:8d:9a:70:3b:ac:70 /dev/stdin (RSA)
    2048 61:63:ee:0d:f6:d2:d8:d6:ae:37:0c:35:ae:da:51:6a /dev/stdin (RSA)

    #read a key from authorized key file
    [root@server01 .ssh]# ssh-keygen -l -f authorized_keys
    2048 87:7a:4d:70:d2:10:a4:4b:b7:e1:2b:7c:77:92:25:04 authorized_keys (RSA)

    #read finger print from remote server
    [root@servers01 ~]# ssh-keygen -l -f /dev/stdin <<< `ssh-keyscan gateway.nerdplanet.org`
    # gateway.nerdplanet.org SSH-2.0-OpenSSH_6.4
    2048 9e:ca:e3:f6:6d:3b:66:4e:4f:ac:1b:b8:3f:9e:46:e5 gateway.nerdplanet.org (RSA)

    #view finger print with random art images
    [root@server01 .ssh]# ssh-keygen -lv -f authorized_keys
    2048 87:7a:4d:70:d2:10:a4:4b:b7:e1:2b:7c:77:92:25:04 authorized_keys (RSA)
    +--[ RSA 2048]----+
    | .E. |
    | . + |
    | o = + |
    | . + O |
    | . S + . |
    | . . = + |
    | + + = . |
    | + . o |
    | |
    +-----------------+

    #copy ssh public keys the easy way
    ssh-copy-id -i .ssh/id_rsa.pub user@remote_host:

    #Easy known hosts file management
    ssh-keygen -R remote-host