Ssh – Temporarily disable ssh public key authentication from client

sshssh-keys

Is there a way to temporarily disable public key authentication when ssh'ing, and use password authentication instead?

I currently want to access remote server, but I'm using another laptop, not mine.

Browsing that link, I found that the command ssh -o PreferredAuthentications=keyboard-interactive -o PubkeyAuthentication=no host1.example.org doesn't work everywhere. And yes, it doesn't work for me. I'm using: OpenSSH_5.9p1 Debian-5ubuntu1, OpenSSL 1.0.1 14 Mar 2012

Edit: I also tried to type ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no
but still have "Permission denied (publickey)".

So, is there a specific configuration to do in the remote server, for that command to work?
Or, when that command will work as expected?

Thanks a lot for advices.

Best Answer

This sounds like a configuration issue on the server side.

If the server allows both public key and password authentication then even if you try to connect without a private key file present on the client, it should prompt you for a password.

If you are getting the error message "Permission denied (publickey)" then it sounds like password authentication is not supported on your server.

Without seeing the /etc/sshd_config file, it is difficult to know but my guess would be that you need to make sure the following line exists:

PasswordAuthentication yes

Restart the ssh server, and when you connect from the client you should be prompted for a password if there is no private key present, or if the private key doesn't match the public key on the server.

A more secure alternative to this of course would be to copy your private key to the laptop which you are using, or in-fact generate a new private key to be used on that laptop and add the public key to .ssh/authorized_keys

Related Solutions

SSH Key – How to Create a Public Key from a Private Key

Use the -y option to ssh-keygen:

ssh-keygen -f ~/.ssh/id_rsa -y > ~/.ssh/id_rsa.pub

From the 'man ssh-keygen'

 -y      This option will read a private OpenSSH format file and print an
         OpenSSH public key to stdout.

Specify the private key with the -f option, yours might be dsa instead of rsa. The name of your private key probably contains which you used. The newly generated public key should be the same as the one you generated before.

Ssh – Ubuntu 9.10 RSA authentication: ssh fails, filezilla runs fine

Your first trace looks somewhat strange. As jneves points out ssh assumes that the file contains your public and private keys. The documentation says that the "identity" is the private key.

 -i identity_file
         Selects a file from which the identity (private key) for RSA or DSA authentication is
         read.

If you do indeed have two keys in one file (had no idea it is possible) you should probably separate them. In any case it seems like you are not conforming to the documentation.

Best Answer

Related Solutions

SSH Key – How to Create a Public Key from a Private Key

Ssh – Ubuntu 9.10 RSA authentication: ssh fails, filezilla runs fine

Related Topic