Password Authentication Issue With Older VNC Servers

[Aergan]

Hi,

I am planning on deploying UltraVNC viewer & server (Currently 1.0.9.5) to our new Windows 7 x86 systems to take advantage of Microsoft ACL authentication for our domain environment.

We have been having major issues with the viewer from 1.0.9.1 to 1.0.9.5L when connecting to our WYSE V10L thin client boxes which run an unknown version of TightVNC server and a single password. Unfortunately, the operating system is propriety and we are unable to do anything with the VNC software other than change the password used.
Instead of getting a password prompt as expected, the Viewer Status says "Password requested" but no prompt displays.

If I downgrade the UltraVNC viewer to version 1.0.8.2 it works as expected and also allows me to connect to UltraVNC 1.0.9.5 servers via ACL but doesn't offer the same level of functionality (e.g. Chat, File Transfer, etc).

Any suggestions to resolve this issue please?

[SteveCena]

I'm having the exact same issue. Windows 7 system and UltraVNC 1.0.95 trying to connect up to VNC 3.3.7. I get the "Password requested" in the notification window, but no password box appears. I've tried making a shortcut on my desktop and using the -password <mypassword> but it doesn't work either.

[SteveCena]

I just downloaded 1.0.8.2, and the password authentication works.

[redge]

delete lang.dll from folder \windows\system32

[diri]

I must confirm the issue:

No password prompt when trying to connect to elder versions.

Tested on Windows XP and 7.

It works when trying to connect to another 1.0.9.5 server. There is no lang.dll envolved on any system.

[Aergan]

delete lang.dll from folder \windows\system32

I am unable to find this file at all on any of the machines.

[yn0t]

I'm seeing the exact issue when talking to our Wyse Thin Clients. It just hangs at the status "password requested". I've setup a test configuration (one without a password) and and am still getting the "password requested" status.

[Rudi De Vos]

Are all the servers with this problem running rfb 3.3.7 ?

[Aergan]

Are all the servers with this problem running rfb 3.3.7 ?

Hi Rudi, I believe the issue may be due to the order the authentication/acceptance is currently using after 1.0.8.2.

In 1.0.8.2:

You send an acceptance request to the user session on the server
Server accepts
You supply valid login details
Server presents you a VNC viewing session.

In 1.0.9.X:

You supply valid login details for session
Server verifies
You send an acceptance request to the user session on the server
Server presents you a VNC viewing session.

[Rudi De Vos]

The bug was actual realvnc 3.3.7 use rfb 3.3
Our viewer handled all rfb except the default old 3.3

Viewer kept waiting on password
Update

http://www.uvnc.eu/download/ultravnc_viewer_10951Q.zip

[pgb00]

Hello

I download the viewer 10951Q and i am the same problem
With version 1095x, we need enter valid login and password before the user accept the session (with older version, it was acceptation and after login)
In normal mode, i have no problem with that but in mode Listenning, it's a problem.

This mode of use is now the normal use of UltraVNC or it's a bug ?

Thanks for your help

[Rudi De Vos]

logon accept is the new order, no bug.

The reason behind this is that we are adding some session selection
( #rdp1, console ...). The popup in that case need to be displayed on
the selected session and we only allow the session selection after the
password check.

But, the server need to switch (if ultravnc viewer or not) to use this new order.
I will test again the invers connection.

[Rudi De Vos]

pgb00

I don't understand the actual problem.

[redge]

In normal mode, i have no problem with that but in mode Listenning, it's a problem.

did you do from vnc server... add new client (initiate connection) to vncviewer listening ?
or
you just run vncviewer -listen for easy and quick acces from system tray without reverse connection and you just do direct connect to vnc server ?

[pgb00]

Hello,

Side Server, I do "Add new client"
Side Viewer, I do viewer.exe /listen

Before 1.0.9.5, i haven't need to login and it was useful for normal users.
I use login with AD with a special group for assistance. But, normal user (who aren't in this group) must do connection in mode Listen
With 1.0.9.5, mode listen need login and it's a problem for me in my use.

Thanks for your help

[Rudi De Vos]

Are you using encryption plugins ?

[Aergan]

The bug was actual realvnc 3.3.7 use rfb 3.3
Our viewer handled all rfb except the default old 3.3

Viewer kept waiting on password
Update

http://www.uvnc.eu/download/ultravnc_viewer_10951Q.zip

This version is working perfectly and has resolved our issue with older VNC versions, thank you very much!
Confirmed working with current builds of our WYSE V10L thinclients.

Looking forward to the next stable release.

[pgb00]

Hello

I install upgrade 10951S and i haven't no more login in Listen mode between server and viewer 10951S

Thanks for all

[pgb00]

Hello,

I re-test with 10951S an d I have again the pb.
I use version 10951S viewer and server with SecurVNCPlugin.dsm
I take the viewer in mode listen and i add a new client side server.
I need a authentification.

With older version, no identification in listen mode. With ARC4plugin.dsm and version 10951S, no identification in listen mode.

Thanks for your help

[Rudi De Vos]

If you use an encryption plugin that require the vncpasswd as part of the
encryption mechanism both server and viewer need to know the passwd.
The request for the password is done by the plugin, not vnc.
Independed of the direction of connection. ( invers/normal)

SecurVNCPlugin.dsm ( see http://adamwalling.com/SecureVNC/ )
+use a key
+use a long passwd ( >8 chars vnc passwd)
+use the vnc passwd "default"
I think it also use a random key, in combination with the passwd.
Config plugin to set value.

ARC4plugin.dsm
+generate a random key

MSRC4plugin
+key
+vncpasswd
Config plugin to set value.

[diri]

http://www.uvnc.eu/download/ultravnc_viewer_10951Q.zip

Quick test on Windows XP connecting with Linux and OS/2:

Works now. Password prompt appears.

Thank you!

cu, diri

[pgb00]

Hello

I used VNCPassword for my tests
With VNC Password, and SecureVNC plugin and mode Listen, i must type the vncpassword

I activate MSLOGON II.
With SecureVNC plugin and mode listen, no need to enter a login / password.

I haven't more problem with that

Thanks for your help