Getting authentication failed error from certain SSH servers

Discussion of open issues, suggestions and bugs regarding network security and data protection solution - SecureBridge
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snorkel
Posts: 384
Joined: Tue 08 Aug 2006 15:10
Location: Milwaukee WI USA

Getting authentication failed error from certain SSH servers

Post by snorkel » Thu 05 Feb 2009 15:58

Hi,
I recently added securebridge tunnel support to replace using putty plink.exe via create process and pipes.

I have one server that I can't connect to with securebridge, it simply returns a error that "Authentication Failed" and there is nothing in the logs on the server.

The server is Gentoo Linux, ssh -v returns:
OpenSSH_3.9p1, OpenSSL 0.9.7i 14 Oct 2005

I need to get this resolved as it's now affecting my customers.
Here is my sshd conf file for the server in question:
# $OpenBSD: sshd_config,v 1.69 2004/05/23 23:59:53 dtucker Exp $

# This is the sshd server system-wide configuration file. See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented. Uncommented options change a
# default value.

#Port 22
#Protocol 2
#ListenAddress 0.0.0.0
#ListenAddress ::

# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key

# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 768

# Logging
#obsoletes QuietMode and FascistLogging
#SyslogFacility AUTH
#LogLevel INFO

# Authentication:

#LoginGraceTime 2m
#PermitRootLogin yes
#StrictModes yes
#MaxAuthTries 6

#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

# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication mechanism.
# Depending on your PAM configuration, this may bypass the setting of
# PasswordAuthentication, PermitEmptyPasswords, and
# "PermitRootLogin without-password". If you just want the PAM account and
# session checks to run without PAM authentication, then enable this but set
# ChallengeResponseAuthentication=no
UsePAM yes
#AllowTcpForwarding yes
#GatewayPorts no
#X11Forwarding no
#X11DisplayOffset 10
#X11UseLocalhost yes
#PrintMotd yes
#PrintLastLog yes
#TCPKeepAlive yes
#UseLogin no
#UsePrivilegeSeparation yes
#PermitUserEnvironment no
#Compression yes
#ClientAliveInterval 0
#ClientAliveCountMax 3
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10

# no default banner path
#Banner /some/path

# override default of no subsystems
Subsystem sftp /usr/lib/misc/sftp-server

snorkel
Posts: 384
Joined: Tue 08 Aug 2006 15:10
Location: Milwaukee WI USA

Post by snorkel » Thu 05 Feb 2009 16:12

OK, I found the issue on the SSH server side.

if the following in the sshd config is set to no:

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

I can't connect with securebridge as a tunnel.

How can I handle the case when a users server has this set to no and they can't control the setting?
How can I get securebridge to send non clear text passwords?

Thanks,

Snorkel

Dimon
Devart Team
Posts: 2910
Joined: Mon 05 Mar 2007 16:32

Post by Dimon » Fri 06 Feb 2009 09:11

When PasswordAuthentication is disabled, you should use PubkeyAuthentication. To use it, you should set the TScSSHClient.Authentication property to atPublicKey and the TScSSHClient.PrivateKeyName property to valid key name.
You can find more detailed information about this in the description of the TScSSHClient.Authentication property the SecureBridge help documentation.

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