OpenSSH 3.7.1 compatibility problems on Linux

[Stanislav Malyshev]

I have build OpenSSH 3.7.1p1 on Linux from src.rpm available for download 
on the site, and after installation I have discovered that this version of 
openssh has many compatibility problems with old and third-party clients 
that previous versions did not have. 
For example:

PuTTY (very popular free Windows client) cannot authenticate user when 
using protocol version 1. Works with protocol version 2.

SecureCRT (another popular commercial Windows client) cannot authenticate 
with password authentication using both protocols 1 and 2, but succeeds 
using "keyboard interactive" authentication.

Various older Unix clients (such as SSH 2.0 or 1.2.27 from ssh.fi, etc.) 
fail to authenticate with both ptotocols 1 and 2. 

With newer clients, using protocol 1 gives very strange greeting - first
Password: 
Response: 
and then if password not given, <user>@<hostname>'s password:
Authentication with the latter never works, however works with the former.

I understand that somehow password authenticatiom method became broken or 
disabled. Is there a way to restore it?

I understand this is very hard to be compatible with all variety of 
existing SSH clients, however all mentioned applications were working 
flawlessly with previous versions of OpenSSH and only after upgrade to 
latest 3.7 version the problems started. Could you give an advice where to 
look for solution or what can be changed to make these clients work again? 
Is there any logging options that could help to see why the server fails 
to authenticate? Syslog shows just "Failed password for <username>" which 
is not very helpful.

-- 
Stanislav Malyshev, Zend Products Engineer   
stas at zend.com  http://www.zend.com/ +972-3-6139665 ext.109