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linuxsshopenwrtdropbear

openWRT Dropbear SSH key authentication fails with "unknown algo"

Good day, I'm trying to figure out how to get a user to ssh into openWRT with only a key. I followed these instructions: https://wiki.openwrt.org/oldwiki/dropbearpublickeyauthenticationhowto.

In short: On a Linux box: If you haven't already got a

.ssh/id_dsa.pub
ssh-keygen -t dsa
scp ~/.ssh/id_dsa.pub [email protected]:/tmp

On openWRT:

cd /etc/dropbear
cat /tmp/id_*.pub >> authorized_keys
chmod 0600 authorized_keys

When I try and ssh in, I get this error:

authpriv.warn dropbear[2085]: Pubkey auth attempt with unknown algo for 'MyUser' from 1.2.3.4:11111

I have tried generating a RSA key too, same result. I can log in as the user using a password:

authpriv.notice dropbear[2089]: Password auth succeeded for 'MyUser' from 1.2.3.4:11111

Solution

  • Maybe it's the problem of the OpenWRT version. Try ${HOME}/.ssh/authorized_keys instead.