How do I set up passwordless RSA/DSA ssh connections under a linux server

Question

I've set up an linux server (32 bit), and would like to be able to ssh in as root based on RSA or DSA key trust. I've appended both public keys to ~/.ssh/authorized_keys and restarted the service; I am still prompted for a password. How do I enable key-based trust for ssh here?

Restarting sshd is not necessary when adding new keys to a server. — EEAA, Feb 24 '12 at 15:26
Beginner questions regarding Linux should be aimed at [unix.se] unless they have a strong System Administrator angle. — Chris S, Feb 24 '12 at 15:40
The checklist provided in @ErikA's answer I had all done. This isn't "I'm a beginner; what do I need to do to get this working;" it's "Why are the standard steps not working?" — Christos Hayward, Feb 24 '12 at 18:59
Add a `-v` to your ssh connect command and post the output. In particular we need to see the bits where key negotiation is happening. — Zoredache, Feb 25 '12 at 01:07
Can you login using a non-root user? If so, you may have `PermitRootLogin no` in your `sshd_config` file. — Khaled, Feb 25 '12 at 08:06

score 0 · Answer 1 · answered Feb 24 '12 at 15:29

0

~/.ssh should be owned by the user and mode 700.
~/.ssh/* should be owned by the user and mode 600.
Each public key should occupy one and only one line of the authorized_keys file.
RSAAuthentication yes should be in your sshd_config.

answered Feb 24 '12 at 15:29

EEAA

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I had all of these in place before asking; is there anything else? – Christos Hayward Feb 24 '12 at 17:03
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Check what gets logged both by the client (`$ ssh -vvv user@host`) and by the server ( in `/var/log/auth.log`) when the user tries to connect with a key. – EEAA Feb 24 '12 at 19:01

score 0 · Answer 2 · answered Feb 24 '12 at 15:32

Check to make sure following is true in the case of your SSHD server

PubkeyAuthentication yes
AuthorizedKeysFile  %h/.ssh/authorized_keys

Sometimes AuthorizedKeysFile switch is directed towards authorized_keys2 file

Then add your public keys under your

/your/home/.ssh/authorized_keys or /your/home/.ssh/authorized_keys2 depending on your configuration.

Yes and finally chmod authorized keys to 600.

****Please also check on "ErikA"'s answer

How do I set up passwordless RSA/DSA ssh connections under a linux server

2 Answers2