Ssh – Using ssh-agent with KDE

kdesshssh-agent

I had this working once before, but for some reason it's not working on my new system.

in .kde4/Autostart/ I have a symlink to ssh-agent called 01-sshagent and then a simple script called 02-sshkeys that looks like this:

/usr/bin/ssh-add $(find $HOME/.ssh/keys -type f | egrep -v '\.pub$')

The problem seems to be that when I startup, ssh-agent is run alright, but KDE doesn't hold onto the output and store it in the environment, so for every Konsole session, I have to run ps to find the PID and then manually type:

SSH_AUTH_SOCK=/tmp/ssh-YtvdiEtW3065/agent.3065; export SSH_AUTH_SOCK;
SSH_AGENT_PID=<pidnumber>; export SSH_AGENT_PID;

…just to get it to work, and it does… just in that Konsole window.

I've tried removing the aforementioned symlink and just havining the ssh script look like this:

/usr/bin/ssh-agent | sh
/usr/bin/ssh-add $(find $HOME/.ssh/keys -type f | egrep -v '\.pub$')

But still, the agent variables aren't in the session and I'm never prompted for the password to my keys.

I'm obviously missing something, but what is it?

Best Answer

My simple solution is to just run one ssh-agent and always keep it running. You can kill it on log-out if you really want to. The key is to just use a fixed socket. Add ssh-agent -a /tmp/$USER.agent to an Autostart script. Then do "export SSH_AUTH_SOCK=/tmp/$USER.agent" followed by ssh-add. Also, you can add that export to your .bashrc, .profile or other shell log-in script and always have access to the agent even when using a remote ssh in.

Related Solutions

Ssh-agent forwarding and sudo to another user

As you mentioned, the environment variables are removed by sudo, for security reasons.

But fortunately sudo is quite configurable: you can tell it precisely which environment variables you want to keep thanks to the env_keep configuration option in /etc/sudoers.

For agent forwarding, you need to keep the SSH_AUTH_SOCK environment variable. To do so, simply edit your /etc/sudoers configuration file (always using visudo) and set the env_keep option to the appropriate users. If you want this option to be set for all users, use the Defaults line like this:

Defaults    env_keep+=SSH_AUTH_SOCK

man sudoers for more details.

You should now be able to do something like this (provided user1's public key is present in ~/.ssh/authorized_keys in user1@serverA and user2@serverB, and serverA's /etc/sudoers file is setup as indicated above):

user1@mymachine> eval `ssh-agent`  # starts ssh-agent
user1@mymachine> ssh-add           # add user1's key to agent (requires pwd)
user1@mymachine> ssh -A serverA    # no pwd required + agent forwarding activated
user1@serverA> sudo su - user2     # sudo keeps agent forwarding active :-)
user2@serverA> ssh serverB         # goto user2@serverB w/o typing pwd again...
user2@serverB>                     # ...because forwarding still works

Ssh – How to activate ssh-agent confirmation in MacOSX Leopard

The agent tries to run a helper program to prompt. On OS X this is not in place by default, so you'll need to provide one (at /usr/libexec/ssh-askpass). I'm currently using one similar to this:

#! /bin/sh  

#  
# An SSH_ASKPASS command for MacOS X  
#  
# Based on script by Joseph Mocker, Sun Microsystems


TITLE=${MACOS_ASKPASS_TITLE:-"SSH Agent"}  

DIALOG="display dialog \"$@\" buttons {\"Deny\", \"Allow\"} default button 2"
DIALOG="$DIALOG with title \"$TITLE\" with icon caution"  

result=`osascript -e 'tell application "Terminal"' -e "$DIALOG" -e 'end tell'`  

if [ "$result" = "button returned:Allow" ]; then
    exit 0 
else  
    exit 1  
fi

Best Answer

Related Solutions

Ssh-agent forwarding and sudo to another user

Ssh – How to activate ssh-agent confirmation in MacOSX Leopard

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