LinuxAnswers - the LQ Linux tutorial section.
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 12-14-2009, 06:02 AM   #1
LQ Newbie
Registered: Dec 2009
Location: Budapest, Hungary
Distribution: MEPIS MX14
Posts: 19

Rep: Reputation: 0
ssh host key problem

I have a problem with a freshly installed openssh server on a MIPS based system (OpenWrt on ADM5120)
I can find both RSA and DSA host keys, but whenever I try to login the following error messages appear:

with putty:
Incoming packet was garbled on decryption

With tunnelier:
packet length toot large (267929772), may be decryption problem

I tried to generate new host keys, but nothing changed (except for the number in the error message of tunnelier)

The length of host keys are:

root@OpenWrt:/# ls -l /etc/ssh
-rw------- 1 root root 672 Jan 1 1970 ssh_host_dsa_key
-rw-r--r-- 1 root root 602 Jan 1 1970
-rw------- 1 root root 975 Jan 1 1970 ssh_host_key
-rw-r--r-- 1 root root 639 Jan 1 1970
-rw------- 1 root root 1675 Jan 1 1970 ssh_host_rsa_key
-rw-r--r-- 1 root root 394 Jan 1 1970
-rw-r--r-- 1 root root 3058 Sep 30 2007 sshd_config

sshd runs with defaults, the config file left intact after installation

Can anyone drop some hint that is this a misconfiguration or whatever ?
Thank you
Old 12-14-2009, 07:55 AM   #2
Registered: Oct 2006
Location: Kenya
Distribution: Ubuntu, RHEL, OpenBSD
Posts: 287

Rep: Reputation: 32
For putty this is what it says on the FAQ's

10.9 "Incoming packet was garbled on decryption"

This error occurs when PuTTY decrypts an SSH packet and the decrypted data makes no sense. This probably means something has gone wrong in the encryption or decryption process. It's difficult to tell from this error message whether the problem is in the client or in the server.
I know this doesnt help much but have you tried a reinstallation?

Last edited by immortaltechnique; 12-14-2009 at 07:56 AM.
Old 12-14-2009, 08:04 AM   #3
Registered: Mar 2002
Location: I can see you from here.
Distribution: Gentoo 1.3b
Posts: 182

Rep: Reputation: 34
Set the proper date/time and try again.
Old 12-14-2009, 10:27 AM   #4
LQ Newbie
Registered: Dec 2009
Location: Budapest, Hungary
Distribution: MEPIS MX14
Posts: 19

Original Poster
Rep: Reputation: 0
Thank you for posting.
I reinstalled sshd - no change
After setting proper date/time - no change.
proper time - reinstall - new key generation - neither of them helped :-(

I tried to connect locally with ssh client from ttyS0 and it was successful :-o
Maybe the algorithm of generating key pairs is different from the standard?

Last edited by Amaranthus; 12-14-2009 at 10:40 AM. Reason: add-on
Old 12-14-2009, 11:31 AM   #5
LQ Newbie
Registered: Dec 2009
Location: Budapest, Hungary
Distribution: MEPIS MX14
Posts: 19

Original Poster
Rep: Reputation: 0
More additions:
When trying to connect with tunnelier the following messages scroll in the status window:

Starting a new SSH2 session
Connecting to SSH2 server
Starting first key exchange
Server version string: SSH-1.99-OpenSSH_4.5
New host key received. Algorithm: ssh-rsa, Size:2048 bits, MD5 Fingerprint:
95:ad:3d:1d:2b:50:70:9c:d6:98:95:f7:52:59:d1:65, Bubble-Babble:
First key exchange completed.
Key exchange:diffie-hellman-group14-sha1. Session encryption: aes256-ctr,
MAC:hmac-sha1, compression: none.
Session terminated on client's behalf:
packet length too large (1460763132), may be decryption problem

The fingerprint above is exact the same as it was appearing when I connected locally

Every idea is welcome what the heck the problem is

Last edited by Amaranthus; 12-14-2009 at 12:22 PM. Reason: correction of spelling
Old 12-15-2009, 03:32 AM   #6
LQ Newbie
Registered: Dec 2009
Location: Budapest, Hungary
Distribution: MEPIS MX14
Posts: 19

Original Poster
Rep: Reputation: 0
Unfortunately, the problem still persists :-(
I discovered that sftp server was not installed despite that sshd_config had the reference to the nonexisting executable file.
However, correcting this did not solve the problem.
I browsed tons of google results on the subject which was obviously very useful, but not for the given problem.

You, guys can't be so heartless as leaving me alone with my stubborn OS, can you? :-)

Even condolences are welcome
Old 12-15-2009, 03:45 AM   #7
LQ Guru
Registered: Jan 2009
Location: Japan
Distribution: Mostly Debian and Scientific Linux
Posts: 5,753

Rep: Reputation: 1287Reputation: 1287Reputation: 1287Reputation: 1287Reputation: 1287Reputation: 1287Reputation: 1287Reputation: 1287Reputation: 1287
Some things you can do to try to understand your problem.

- Look at the logs from sshd (but maybe no logging on OpenWRT)
- Run sshd manual in debug mode: outputs verbose info to terminal
- Try to connect using a proper ssh client from a remote machine



Last edited by evo2; 12-15-2009 at 03:47 AM. Reason: OpenWRT specific
1 members found this post helpful.
Old 12-15-2009, 03:42 PM   #8
LQ Newbie
Registered: Dec 2009
Location: Budapest, Hungary
Distribution: MEPIS MX14
Posts: 19

Original Poster
Rep: Reputation: 0
Thank you very much for your advices.
I don't know, what the difference is between putty, and a Linux Mint ssh client that caused the error with putty.
I tried to connect with my notebook, which has a Mint8 installed and lo! ssh went smoothly.
It seems that there is some feature on a "normal" sshd which is not implemented in the OpenWrt version. Or simply the defaults are different. If the latter is the case, I have to figure out the correct settings.
I've been using putty for ages, without problems, whether connecting to a linux or a win ssh server.
However, I take this thread solved, since the ssh server works now.
Thank you again for your help.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Limit ssh session from a host with a particular Key file hemanshurpatel Linux - Security 13 07-24-2009 02:36 AM
How to know/find out/see my ssh host key khaos83 Red Hat 4 12-26-2007 03:35 AM
ssh Host Key ziox Linux - Networking 6 02-07-2005 02:57 PM
to 2.6.10 from 2.4.26 | ssh client | Host key verification failed kaN5300 Slackware 6 01-05-2005 10:04 PM
SSH rejects my host key for version 2 only. Travis86 Linux - Networking 19 08-08-2003 03:48 AM

All times are GMT -5. The time now is 11:23 AM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration