4 ms·

SSH Key Gen/Install Script. Automates Mass Distribution of SSH Keys

45 points by a904guy 16y ago

seanieb 16y ago
It seems to be down for me. Here's the Google cache: http://webcache.googleusercontent.com/search?q=cache%3Ahttp%3A%2F%2Fblog.mediafederation.com%2Fandy-hawkins%2Fssh-keygen-distribution-skd-install-ssh-keys-automatically%2F&ie=utf-8&oe=utf-8 http://webcache.googleusercontent.com/search?q=cache%3Ahttp%...
- a904guy 16y ago
  MediaTemple VPS... Time to migrate to my rackspace server.
  - mtmatt 16y ago
    Saw that you were having some issues. Took a look, and everything seemed to be working fine. Let us know if we can help out with anything.
duskwuff 16y ago
Wait, it's creating a separate public key in your home directory on every device listed, all with the same (plaintext!) passphrase, then sets up every device to SSH to any other one? Smells like bad practice!
- a904guy 16y ago
  For your comment that was edited stating: "the script was storing passwords in plain-text in the user home folder", There is no plaintext passphrases stored anywhere... and you can use different passwords per each device per the config file. This script follows the exact procedure for ssh-keys defined by OpenSSHD in general, ssh-keys are more secure than logging in using a password in general. As for the reverse connections, I have a version that utilizes the reverse key in the config array that keeps them from distributing across server, only to and from the localhost. I took it out to roll this version out as I still haven't tested it fully.
  - duskwuff 16y ago
    > There is no plaintext passphrases stored anywhere... Sure there are - in the config file, and in the command line. 59: `ssh-keygen -q -f ~/.ssh/id_{$server['type']} -t {$server['type']} -N '{$server['remote_pass']}'`; 71: $server['conn']->shell("ssh-keygen -q -f ~/.ssh/id_{$server['type']} -t {$server['type']} -N '{$server['remote_pass']}'"); It gets even better - if you forgot to set REMOTE_PASS in the config file, it defaults to empty, and you end up with a passwordless key on most of your machines: 39: $_SERVERS[$k]['remote_pass'] = ($_SERVERS[$k]['remote_pass']) ? $_SERVERS[$k]['remote_pass'] : '' ; Even if you're only copying keys "to and from the localhost", you've still just given all your servers access -- likely without a password -- to your desktop computer.
    - a904guy 16y ago
      When you run ssh-keygen it creates the two keys, public and private, neither contain the 'plaintext' passphrase in your home directory like you mentioned. The only concern may be bash history, I'll include a wipe for that. Secondly, even while being transmitted using SSH they are NOT in plain-text. As the SSH connection itself is encrypted, so while executed in plaintext, the password is NOT stored in plain text, or transmitted in plaintext as identified by those commands. Finally, the remote_password being blank is by design, passwordless keys are less of a security threat than any weak user supplied password. They serve their purpose in the real world amongst private networks. EDIT for 'and in the command line.': Reviewing the command history doesn't show the libssh2 or php5 commands being executed on either BSD or debian. EDIT for your comment 'in the config file': If your suggesting that the software is insecure by the fact that the user leaves the config file after usage, then perhaps that user should be allowed in the environment to begin with.
      - zwp 16y ago
        The command, including password, is also visible in the process table. Some unices limit visibility of other users' processes but many do not.
        16y ago
- vvatsa 16y ago
  PHP => Pretty Huge Problem
  - a904guy 16y ago
    The language doesn't really matter, especially considering its a single use app. It can be done via any LibSSH2 binding, or even with a more complex expect binding. The reason for php is simple, I had already wrote the libssh2 code for what I needed. I submitted it, in hopes it saves someone else the time.
theBobMcCormick 16y ago
Are you really generating a separate keypair for each server? Why? Why not generate one key pair on your management host, and then use the standard "ssh-copy-id" command to push the public key out to each managed server?
- a904guy 16y ago
  For the ability to remove a key from a single device/server. Considering the keys are tagged with user+host, removal is easily identifiable. A single key solution isn't ideal for my configuration. Using ssh-copy-id is the standard method, but doesn't suite what I wanted.
  - theBobMcCormick 16y ago
    Why would you want to remove a key on the management server? Why have all keys copied to all servers? You say ssh-copy-id doesn't suite what you want, but you could easily create a much shorter script that just loops over the list of server and runs ssh-copy-id.
kilburn 16y ago
An option in the config file to specify key length would be good IMHO.
- a904guy 16y ago
  Ahh! good catch, Thank you. I'll zdd that in tomorrow.
lobster_johnson 16y ago
This seems wrong and overengineered for so many reasons. PHP, really? A simple one-line script will suffice to copy keys with ssh-copy-id or similar. (It gets even simpler if you use something like dsh or Capistrano.)

45 points by a904guy 16y ago

It seems to be down for me. Here's the Google cache: http://webcache.googleusercontent.com/search?q=cache%3Ahttp%3A%2F%2Fblog.mediafederation.com%2Fandy-hawkins%2Fssh-keygen-distribution-skd-install-ssh-keys-automatically%2F&ie=utf-8&oe=utf-8 http://webcache.googleusercontent.com/search?q=cache%3Ahttp%...

a904guy 16y ago
MediaTemple VPS... Time to migrate to my rackspace server.
- mtmatt 16y ago
  Saw that you were having some issues. Took a look, and everything seemed to be working fine. Let us know if we can help out with anything.

duskwuff 16y ago

Wait, it's creating a separate public key in your home directory on every device listed, all with the same (plaintext!) passphrase, then sets up every device to SSH to any other one? Smells like bad practice!

a904guy 16y ago
For your comment that was edited stating: "the script was storing passwords in plain-text in the user home folder", There is no plaintext passphrases stored anywhere... and you can use different passwords per each device per the config file. This script follows the exact procedure for ssh-keys defined by OpenSSHD in general, ssh-keys are more secure than logging in using a password in general. As for the reverse connections, I have a version that utilizes the reverse key in the config array that keeps them from distributing across server, only to and from the localhost. I took it out to roll this version out as I still haven't tested it fully.
- duskwuff 16y ago
  > There is no plaintext passphrases stored anywhere... Sure there are - in the config file, and in the command line. 59: `ssh-keygen -q -f ~/.ssh/id_{$server['type']} -t {$server['type']} -N '{$server['remote_pass']}'`; 71: $server['conn']->shell("ssh-keygen -q -f ~/.ssh/id_{$server['type']} -t {$server['type']} -N '{$server['remote_pass']}'"); It gets even better - if you forgot to set REMOTE_PASS in the config file, it defaults to empty, and you end up with a passwordless key on most of your machines: 39: $_SERVERS[$k]['remote_pass'] = ($_SERVERS[$k]['remote_pass']) ? $_SERVERS[$k]['remote_pass'] : '' ; Even if you're only copying keys "to and from the localhost", you've still just given all your servers access -- likely without a password -- to your desktop computer.
  - a904guy 16y ago
    When you run ssh-keygen it creates the two keys, public and private, neither contain the 'plaintext' passphrase in your home directory like you mentioned. The only concern may be bash history, I'll include a wipe for that. Secondly, even while being transmitted using SSH they are NOT in plain-text. As the SSH connection itself is encrypted, so while executed in plaintext, the password is NOT stored in plain text, or transmitted in plaintext as identified by those commands. Finally, the remote_password being blank is by design, passwordless keys are less of a security threat than any weak user supplied password. They serve their purpose in the real world amongst private networks. EDIT for 'and in the command line.': Reviewing the command history doesn't show the libssh2 or php5 commands being executed on either BSD or debian. EDIT for your comment 'in the config file': If your suggesting that the software is insecure by the fact that the user leaves the config file after usage, then perhaps that user should be allowed in the environment to begin with.
    - zwp 16y ago
      The command, including password, is also visible in the process table. Some unices limit visibility of other users' processes but many do not.
      - 16y ago
vvatsa 16y ago
PHP => Pretty Huge Problem
- a904guy 16y ago
  The language doesn't really matter, especially considering its a single use app. It can be done via any LibSSH2 binding, or even with a more complex expect binding. The reason for php is simple, I had already wrote the libssh2 code for what I needed. I submitted it, in hopes it saves someone else the time.

theBobMcCormick 16y ago

Are you really generating a separate keypair for each server? Why? Why not generate one key pair on your management host, and then use the standard "ssh-copy-id" command to push the public key out to each managed server?

a904guy 16y ago
For the ability to remove a key from a single device/server. Considering the keys are tagged with user+host, removal is easily identifiable. A single key solution isn't ideal for my configuration. Using ssh-copy-id is the standard method, but doesn't suite what I wanted.
- theBobMcCormick 16y ago
  Why would you want to remove a key on the management server? Why have all keys copied to all servers? You say ssh-copy-id doesn't suite what you want, but you could easily create a much shorter script that just loops over the list of server and runs ssh-copy-id.

kilburn 16y ago

An option in the config file to specify key length would be good IMHO.

a904guy 16y ago
Ahh! good catch, Thank you. I'll zdd that in tomorrow.

lobster_johnson 16y ago

This seems wrong and overengineered for so many reasons. PHP, really? A simple one-line script will suffice to copy keys with ssh-copy-id or similar. (It gets even simpler if you use something like dsh or Capistrano.)