Name

sshexport — install ssh public keys on remote servers

Synopsis

sshexport [-h] [-c] [-p port] [-r] [-d] [-v] name@host...

Description

This script tries to export ssh public keys to specified sites. It will walk the user through generating key pairs if it doesn't find any to export. It handles all the fiddly details, like remembering the ssh keyfile names, updating the authorized_keys and making sure local and remote permissions are correct. It tells you what it's doing if it has to change anything.

Each name@host argument is the name of a host where your public keys should be installed. If it contains a @, the part before the @ will be clipped off and used as the login name. Otherwise your local login name will be used.

Note: this script does not parse your ssh configuration — therefore, if you have specified a different remote user in your configuration, this script will not know that. You can use the user@host syntax to force the remote username.

On any remote Linux system using selinux, the security context of root's authorized_keys is restored whenever it is modified or deleted.

Recording remote key locations

If either of the files ~/.config/sshexport or ~/.ssh/sshexport.rc exists, places where you install keys will be recorded in it, along with the password used to access the host and the port (if non-default). This record will also be updated when you use the check option, so you can use that option to check sites where you may have previously installed keys and add them to the list. Entries are edited when you delete remote keys; the key is deleted, but not the password and port information.

Beware that if your account is cracked, this record will offer the intruder a menu of other systems to attack, escalating security risks. Thus, to enable the recording feature, you must explicitly create ~/.ssh/sshexport.rc or ~/.config/sshexport.rcusing touch(1) or some other means. This tool will not create the file for you. Also, it checks permissions on these files at startup and bails out with a message if they are not limited to the owning user.

Options

Invoked with the -h option, the program prints a usage summary and exits.

Invoked with the -c option, the program checks your local and remote ssh configuration for problems without changing anything (except that your record of where you have installed keys is updated).

The -p option allows you to set a port number, overriding the default 22. This may be useful if you have a firewall and port forwarding setup. Port numbers are recorded if you have recording set up.

Invoked with the -d option, the program deletes any public keys under the specified login at the specified host. The password and the -p option need not be specified if an entry was recorded for this host. The configuration entries for any such keys are also removed, but not port and password information.

The -r force-installs your keys on all sites recorded in your installation log. By removing your keys (to force a key pair generation) you can ship new keys to all sites.

The -v option says to report all commands and responses during the session. It's mainly useful for debugging.

Files

Sites where keys have been installed may be recorded in ~/.sshexport or ~/.config/sshexport. (the second location is preferred if ~/.config) exists.

Requirements

sshexport was written in Python 2.2a1. It will not work under Python 1.5.2.

Bugs

This program relies on ptys to work correctly in combination with exec, but some implementations (notably under FreeBSD) don't. Suspect this if you see termination with the message "Remote ls returned empty string, bailing out"

If you encounter this or any other bug, the first thing to do is run with -v and see if that clarifies matters. If not, send the maintainer a session transcript.

See Also

ssh(1), ssh-keygen(1).

Author

Eric S. Raymond .

There is a project web page at http://www.catb.org/~esr/sshexport/.