ssh authorized keys to connect to AirOS 3.2 over ssh

[kawarmc]

Hi guys,

Do you know where do I have to save my ssh keys to be able to connect to a NanoStation or PowerStation without having to type any password?

Thanks

[UBNT-Mike.Ford]

Hello Kawa,

I'm asking my software engineer to jump in here.

Thanks,

Mike

[kawarmc]

Hi again guys.

Did you find any solution to the problem of how to store the authorized keys on the AirOS 3.2 firmware?

Thanks in advance.

[UBNT-keba]

All sshd (dropbear) keys are sitting in /etc/persistent/ directory.

[marc_dilasser]

All sshd (dropbear) keys are sitting in /etc/persistent/ directory.
Seems dropbear doesn't find authorized_keys in /etc/persistent, but search this file in $HOME/.ssh/. The $HOME of root (/) is not writable.
So you have to change the $HOME of root to /tmp, create /tmp/.ssh and copy authorized_keys to /tmp/.ssh.
You can do that in /etc/persistent/rc.poststart :


#!/bin/sh
if [ -f /etc/persistent/authorized_keys ]; then
sed -ie 's/inistrator:.*:\/bin\/sh/inistrator:\/tmp\/:\/bin\/sh/' /etc/passwd
mkdir -p /tmp/.ssh
cp /etc/persistent/authorized_keys /tmp/.ssh
fi


Copy your public key in /etc/persistent/authorized_keys

Save and reboot

cfgmtd -w -p /etc/
/sbin/reboot


It's running like that for me on AirOS 3.2.

[UBNT-keba]

marc_dilasser is absolutely right that / is not writable but there is a key in system.cfg that allows to specify home directory for the user:

users.<idx>.homedir=<home_direcotry>

default is /

Homedir key is available from v3.2.

So
users.1.homedir=/etc/persistent
in system.cfg and
/etc/persistent/.ssh/authorized_keys file should help there without any /etc/persistent/rc.poststart custom script.

I think we can reconfigure ssh to search for authorized_keys directly in /etc/persistent like it is doing with dropbear_dss_host_key and dropbear_rsa_host_key but it could be a problem with multi-user access.

[marc_dilasser]

marc_dilasser is absolutely right that / is not writable but there is a key in system.cfg that allows to specify home directory for the user:

users.<idx>.homedir=<home_direcotry>

default is /

Homedir key is available from v3.2.
...


Thanks for the key homedir, usefull for me.

Marc

[kawarmc]

Thank you very much guys.

I'll try all this later this evening...

[kawarmc]

Thank you guys. Everything is working right now.

I used the homedir aproach and everything is running smootly.

[baast]

Hey Guys,

When i try to change my home directory to "/etc/persistent" on my NanoStation5, i get the following error when trying to connect trough ssh after the save/reboot:

ubnt@192.168.1.20's password:
[273] Oct 21 22:04:38 exit after auth (ubnt): error changing directory
Connection to 192.168.1.20 closed.

I copied over the "users.1.homedir=/etc/persistent" line exactly into my system.cfg
After it failed the first time i restored the facotry defaults and then tried again, but no luck.

Im running the following firmware version: XS5.ar2313.v3.2.2.3891.081021.

Thx in advance for any help,

Tim.

[baast]

Its solved already, had to change my user to something other then root or ubnt.

Thx anyways,

Tim.

[UBNT-Mike.Ford]

Thanks for the update Tim.

Mike

[misiek1]

Hello

I got still problem with auth using public key

I done already :
on my comp:
michal@michal-HP530:~$ sudo su root
root@michal-HP530:/home/michal# ssh-keygen -t dsa
Your public key has been saved in /root/.ssh/id_dsa.pub


on NS2 XS2.ar2316.v3.6.4703.101129.1107:
mkdir -p /etc/persistent/.ssh
scp ~/.ssh/id_dsa.pub ubnt@10.1.0.103:/etc/persistent/.ssh/authorized_keys

added to /tmp/system.cfg on NS2:
users.1.homedir=/etc/persistent
users.1.name=ubnt
users.1.password=VvpvCwhccFv6Q
users.1.status=enabled

then:
cfgmtd -w -p /etc/
reboot

after that i got:
[307] Nov 29 11:12:26 exit after auth (ubnt): error changing directory
Connection to 10.1.0.103 closed.