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SFTP auto login works one way only?

Hello all.

I have read many posts on auto login for SSH but can not figure this one out.

Code:

#ssh-keygen -t rsa



-rw-r--r-- 1 root root  415 2008-10-01 04:07 authorized_keys

-rw------- 1 root root 1.7K 2008-09-30 18:47 id_rsa

-rw-r--r-- 1 root root  413 2008-09-30 18:47 id_rsa.pub

-rw-r--r-- 1 root root  884 2008-10-01 03:33 known_hosts

Example:

Server A cannot auto login (sftp) to server B

Server B can auto login (sftp) to server A

Server A: Debian (etch)
Linux 2.6.18-4-amd64 #1 SMP Mon Mar 26 11:36:53 CEST 2007 x86_64 GNU/Linux

Server B: Debian (etch)
Linux 2.6.18-5-686 #1 SMP Fri Jun 1 00:47:00 UTC 2007 i686 GNU/Linux

My only thought is that something changed in the newest version of Etch.
Any ideas?

Jon

Hi.

Check the permissions on the home directories as well as the .ssh directories and the keys.

Also, try running ssh -vvv in both directions to see if there's anything interesting.

Dave

Thank you for the reply.

I keep getting blacklisted on the server I am trying to auto ssh to.
/var/logs/auth.log

Oct 1 10:43:50 www sshd[2444]: Public key 4f:d7:71:27:51:bf:5e:a9:b7:af:2c:82:0d:2a:bb:53 blacklisted (see ssh-vulnkey(1))

You got me on the right track, though it turns out it is a problem between the new version of open-ssh and prior versions. From what I read if both servers do not have the newest version it will not work. I upgraded both servers with openssl_0.9.8.

http://www.ducea.com/2008/05/14/ssh-vulnkey-a/

My problem is that my x86_64 version wil not upgrade to the newest version.

64 bit

Code:

ii  openssh-blacklist                0.1.1                                list of blacklisted OpenSSH RSA and DSA keys

ii  openssh-client                    1:4.7p1-8                            secure shell client, an rlogin/rsh/rcp repla

ii  openssh-server                    1:4.7p1-8                            secure shell server, an rshd replacement

ii  ssh                              1:5.1p1-2                            secure shell client and server (metapackage)

ii  openssl                          0.9.8c-4etch3                        Secure Socket Layer (SSL) binary and related

i686

Code:

ri  openssh-blacklist                0.1.1                                list of blacklisted OpenSSH RSA and DSA keys

ii  openssh-client                    4.3p2-9etch3                        Secure shell client, an rlogin/rsh/rcp repla

ii  openssh-server                    4.3p2-9etch3                        Secure shell server, an rshd replacement

ii  ssh                              4.3p2-9etch3                        Secure shell client and server (transitional

openssl                          0.9.8c-4etch3                        Secure Socket Layer (SSL) binary and related

Anyway to bypass the black list?

You can get around this by regenerating your host keys. Should be something like:

# ssh-keygen -f /etc/ssh/ssh_host_rsa_key -N '' -t rsa
# ssh-keygen -f /etc/ssh/ssh_host_dsa_key -N '' -t dsa

This will cause any client to shout about key fingerprints when the SSH/SFTP in, which may break automated pub-priv key logins until the new host fingerprints are accepted, so be warned.

Dave

Well I figured it out.

http://www.debian.org/security/2008/dsa-1571

http://wiki.debian.org/SSLkeys

Turns out that I needed to do this:

Code:

rm /etc/ssh/ssh_host_*

dpkg-reconfigure openssh-server

Then it recreated the keys without black listing them.

Thanks for your help Dave.
Your suggestions led me to the answer.

Jon

i am using fedora7 64 i want to login to other machine by rsh without password. there is no xinetd in my /etc dir. rsh appears only in /usr/bin/rsh or in pam.d directory.

please help me how can i configure rsh and login using rsh command?

Thanks

Saleemsupra

Hi saleemsupra.

I setup ssh using "ssh-keygen -t rsa", then copied the id_rsa.pub key to the authorized_keys file of the remote server/user to connect to. Manually login once using ssh or sftp to the remote server. After that is setup it seems to work well for me.

#rsh -l [remote user] -p [remote port] [url / IP] [command]

#rsh -l myuser -p 22 192.168.2.55 echo

I hope that helps to answer your question.

Jon