SSHD broken

Punker51 · 02-24-2004, 11:09 AM

I have my server running for one month and suddenly i cant connect to my sshd server anymore.

When i try to connect with putty, it asks me for my password. If i give the good password, the window disapear and the connection is closed.

When i try to connect with WINSCP on port 22
i get this window:

http://punker.brutalfield.com/uploads/screen1.bmp

I will post what i get when i execute "sshd punker@localhost:22" from the shell when i get home

Thanks a lot for replying
I really need to make it work again

colnago · 02-24-2004, 11:47 AM

If you can get to a real terminal, try 'ssh -v ...', as that will tell you most of what is going on with the authentication.

Punker51 · 02-24-2004, 01:23 PM

Quote:

Originally posted by colnago
If you can get to a real terminal, try 'ssh -v ...', as that will tell you most of what is going on with the authentication.

this is what i get when i run the command from the local shell

Code:

[root@justdome root]# ssh -v punker@localhost

OpenSSH_3.4p1, SSH protocols 1.5/2.0, OpenSSL 0x0090607f
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Rhosts Authentication disabled, originating port will not be trusted.
debug1: ssh_connect: needpriv 0
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: Remote protocol version 1.99, remote software version OpenSSH_3.4p1
debug1: match: OpenSSH_3.4p1 pat OpenSSH*
Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_3.4p1
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: dh_gen_key: priv key bits set: 131/256
debug1: bits set: 1549/3191
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'localhost' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:2
debug1: bits set: 1589/3191
debug1: ssh_rsa_verify: signature correct
debug1: kex_derive_keys
debug1: newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: waiting for SSH2_MSG_NEWKEYS
debug1: newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: done: ssh_kex2.
debug1: send SSH2_MSG_SERVICE_REQUEST
debug1: service_accept: ssh-userauth
debug1: got SSH2_MSG_SERVICE_ACCEPT
debug1: authentications that can continue: publickey,password,keyboard-interactive
debug1: next auth method to try is publickey
debug1: try privkey: /root/.ssh/identity
debug1: try privkey: /root/.ssh/id_rsa
debug1: try privkey: /root/.ssh/id_dsa
debug1: next auth method to try is keyboard-interactive
debug1: authentications that can continue: publickey,password,keyboard-interactive
debug1: next auth method to try is password
punker@localhost's password:
debug1: ssh-userauth2 successful: method password
debug1: channel 0: new [client-session]
debug1: send channel open 0
debug1: Entering interactive session.
debug1: channel_free: channel 0: client-session, nchannels 1
Connection to localhost closed by remote host.
Connection to localhost closed.
debug1: Transferred: stdin 0, stdout 0, stderr 81 bytes in 0.0 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 45151.9
debug1: Exit status -1

Punker51 · 02-24-2004, 01:38 PM

and here is my sshd_config file

Code:

#	$OpenBSD: sshd_config,v 1.56 2002/06/20 23:37:12 markus Exp $

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

# This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin

# 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 2,1
#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 3600
#ServerKeyBits 768

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

# Authentication:

#LoginGraceTime 600
#PermitRootLogin yes
#StrictModes yes

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

# rhosts authentication should not be used
#RhostsAuthentication no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes
# 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

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

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

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

#AFSTokenPassing no

# Kerberos TGT Passing only works with the AFS kaserver
#KerberosTgtPassing no

# Set this to 'yes' to enable PAM keyboard-interactive authentication 
# Warning: enabling this may bypass the setting of 'PasswordAuthentication'
#PAMAuthenticationViaKbdInt yes

X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#PrintMotd yes
#PrintLastLog yes
#KeepAlive yes
#UseLogin no
UsePrivilegeSeparation yes
#Compression yes

#MaxStartups 10
# no default banner path
#Banner /some/path
#VerifyReverseMapping no

# override default of no subsystems
Subsystem	sftp	/usr/lib/ssh/sftp-server
AllowUsers punker
PermitRootLogin no

Punker51 · 02-24-2004, 04:33 PM

for those that interests (if any)
i found the solution (with help from ppl on #linux on undernet)

all the passwords were still functioning but they were outdated
so i just changed my passwords and its working again

unSpawn · 02-24-2004, 05:53 PM

..in addition to that please:
1. DO NOT use protocol v1: it's not as secure as v2.
2. DO NOT log in as the root account user: use an unprivileged account, then use sudo/su to perform tasks that need root privileges.