I installed openSSH and using PuTTY on a Win2k machine.

I didn't setup any public key on the Linux for my user account. There is no ~/.ssh directory at all. But I can still login remotely. How come?

login as: user1
Server refused our key
Password:
Last login: Wed Apr 14 18:07:32 2004 from 1.2.3.4
Have a lot of fun...
user1@linux:~>

You are looking for YOUR keys in your home directory. These are the keys generated and employed for your use in connecting to an ssh server. The pub/private pair that the machine owns, and uses to facilitate and maintain incoming connections reside in /etc/ssh or /etc/sshd.

I am sorry I didn't phase the question properly. My question is, how come I can still login to Linux using PuTTY on port 22 without a correct public key copied to my Linux account?

Here is what I have done:
1. Linux SuSE 9.0 with openSSH installed.
2. WinNT with PuTTY and SSH enabled.
3. Generate public and private key on PuTTY.
4. *** Did not copy the public key to Linux ***
5. Use PuTTY connect to Linux port 22.
6. Somehow I can still login.

Why did it work? Is my login name and passwd transmitted in SSH? Is my session still inside SSH after I logged in?

You tried to send your private key but the server refused it bc it didnt have any public key for user1. So it asked for your linux password and u entered it -> u were successfully logged in.

You will have to configure your sshd to not accept password logins, else it will try password if the keys are missing/wrong.

Thanks for the explainations.

I attach my sshd_config here. As you can see, I already set "PasswordAuthentication no" Doesn't that turn off password auth?


# This is the sshd server system-wide configuration file. See
Port 22
Protocol 2
HostKey /etc/ssh/ssh_host_rsa_key

#RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile .ssh/authorized_keys

# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes

# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication no
#PermitEmptyPasswords no

# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCreds yes

# Set this to 'yes' to enable PAM authentication (via challenge-response)
# and session processing. Depending on your PAM configuration, this may
# bypass the setting of 'PasswordAuthentication'
UsePAM yes

#KeepAlive yes
#UseLogin no
UsePrivilegeSeparation no
#PermitUserEnvironment no
Compression yes

Subsystem sftp /usr/lib/ssh/sftp-server