VncViewer Listen crashes; SC claims connection

iamchris · Post by **iamchris** » 2005-05-25 19:21

SC 20.3; UVNC 20.6 (fixed) (also tried RC18 and RC 20.5) 20.5 and 20.6 both report 20.4 in the About Dialog.

I've created my SC with my RC4.key file and a properly written helpdesk.txt file. When the end-user executes the SC program, and double-clicks to connect to me, I receive the incoming request msgbox. I then select yes. I can see the initial loading screen, and then UVNC Listener disappears. Poof.

I am using the RC4 plugin. I've tried the version of the plugin that comes with UVNC 20.5 (plain and noreg), Plugin v 117 (plain and noreg), and the dsm plugin from inside the SC 7-zip archive (which is noreg).

I can't find a logging option in vncviewer to find out what's going on.

Please advise!! TIA!

Post by **Rudi De Vos** » 2005-05-25 20:10

You tried a lot of versions and plugins...

But did you tried it also without plugin ?
Did you tried it between 2 internal PC's ?

Hard to tell what cause it....we need first to narrow the problem

Firewall ?
Plugin problem ?

iamchris · Post by **iamchris** » 2005-05-27 12:55

Good suggestion. I hadn't thought about trying it without the plugin.

It works fine without the DSM plugin.

Of course, encryption is a must-have feature.

I have tried 5 different DSM plugins, 2 versions, plain and noreg, and the one distributed inside the SC executable.

Again, I need some direction.

Thanks!

Post by **Rudi De Vos** » 2005-05-27 13:38

Please check this, sombody posted an answer to the same question

[topic=2983][/topic]

scovel · Post by **scovel** » 2005-05-27 13:46

Rudi,

Is the name of the plugin hard-coded into the SC exe? Is it hard-coded to MSRC4Plugin.DSM? If so, this is going to be a problem going forward.

The MSRC4Plugin.DSM doesn't work with SC. The MSRC4Plugin_NoReg.DSM does. Actually, so do all the newer Beta plugins, with very different names. This is going to cause confusion, support issues, and loss of hair. Perhaps the plugin name could be passed in?

-plugin msrc4plugin_noreg.dsm

What do you think?

Sean

Post by **Rudi De Vos** » 2005-05-27 17:21

Yep,

Plugin name is hardcoded.
As long as the users rename there plugin to MSRC4Plugin.DSM before they add them to the zip it works..

Are MSRC4Plugin_NoReg.DSM and MSRC4Plugin.DSM not compatible.
Viewer use MSRC4Plugin.DSM and you add the MSRC4Plugin_NoReg.DSM
as MSRC4Plugin.DSM in SFX should work.

No plans to add extra command line options to SC...
If special things are needed helpdesk.txt is a better way.

scovel · Post by **scovel** » 2005-05-27 17:33

Rudi,

Plugin name is hardcoded.

Oy! That explains that...

Are MSRC4Plugin_NoReg.DSM and MSRC4Plugin.DSM not compatible.

Compatible, yes. The same, no. MSRC4Plugin.dsm is looking to read/write stuff in the registry. It will NEVER find the key file. It probably blows up big-time trying to create a key file if the registry isn't setup correctly...

No plans to add extra command line options to SC...
If special things are needed

Well, maybe you could change the hard-coded name to something generic? And make sure the docs say to "copy your plugin to xxxx.dsm" before creating your SFX file. That way it won't look like MSRC4Plugin.dsm works with SC.

Also, ARC4Plugin.dsm, AESPlugin.dsm, and AESV2Plugin.dsm will work with SC.

Sean

iamchris · Post by **iamchris** » 2005-05-27 21:05

Changed the DSM plugin to 117 on both the Viewer and SC sides, generated new keys, 7z'ed the files myself, and rebuilt the SFX using 7zS.sfx which runs winvnc.exe on execute.

Odd: It will function on a paricular Windows 2000 machine that I'm using for testing. It fails on a different Windows XP machine that I was using for testing.

I have some logs:

msrc4.log

05/27/05 16:18:20 : StartUp
05/27/05 16:18:20 : NOREG MS RC4 Plugin,Sean E. Covel,Mar 12 2005,1.1.7.0,MSRC4Plugin.dsm
05/27/05 16:18:20 : GetEnvVar (getenv) dsmdebug = 1
05/27/05 16:18:20 : dsmdebug = 1
05/27/05 16:18:20 : Set Params
05/27/05 16:18:20 : NOREG MS RC4 Plugin,Sean E. Covel,Mar 12 2005,1.1.7.0,MSRC4Plugin.dsm
05/27/05 16:18:20 : InitVars
05/27/05 16:18:20 : GetCryptoVersion.
05/27/05 16:18:20 : Acquiring the Crypto Context.
05/27/05 16:18:20 : Crypto acquired a Crypto Provider Context.
05/27/05 16:18:20 : Crypto Version = 2
05/27/05 16:18:20 : OS is 'Windows XP'
05/27/05 16:18:20 : Using provider ''
05/27/05 16:18:20 : Max Key Length 128
05/27/05 16:18:20 : SetParams - StartUp.
05/27/05 16:18:20 : ***** VIEWER Application *****
05/27/05 16:18:20 : Trying to find the key file
05/27/05 16:18:20 : Looking at msrc4pluginkey
05/27/05 16:18:20 : GetEnvVar (getenv) msrc4pluginkey = "c:\program files\UltraVNC\rc4.key"
05/27/05 16:18:20 : msrcpluginkey "c:\program files\UltraVNC\rc4.key"
05/27/05 16:18:20 : Looking for rc4.key
05/27/05 16:18:20 : Found key at rc4.key
05/27/05 16:18:20 : CryptAcquireContext |14076496| || || |1| |-268435456|
05/27/05 16:18:20 : CryptAcquireContext |14076500| || || |1| |-268435456|
05/27/05 16:18:20 : Reading KeyBlob
05/27/05 16:18:20 : Importing ExponentOfOne KeyBlob
05/27/05 16:18:20 : Importing KEY KeyBlob
05/27/05 16:18:20 : Reading KeyBlob
05/27/05 16:18:20 : Importing ExponentOfOne KeyBlob
05/27/05 16:18:20 : Importing KEY KeyBlob
05/27/05 16:18:20 : Key File Read.
05/27/05 16:18:44 : Shutting Down.

vncviewer.log

Started and Winsock (v 2) initialised
In listening mode - staring daemons
Adding tray icon
Checking tray icon
bufsize expanded to 4352
Registered connection with app
RFB server supports protocol version 3.16
Connected to RFB server, using protocol version 3.4
No authentication needed
Clipboard changed
Don't send initial clipboard!
Desktop name "WinVNC "
Geometry 1280 x 1024 depth 32
Screen work area is 1280 x 960
Cache: Cache buffer bitmap creation
Screen work area is 1280 x 960
Update-processing thread started
Screen work area is 1280 x 960
Screen work area is 1280 x 960
bufsize expanded to 16640
Receiving cursor shape update, cursor 32x32
Receiving cursor shape update, cursor 32x32
Checking tray icon
Receiving cursor shape update, cursor 32x32
Checking tray icon
rdr::Exception (2): rdr::SystemException: read: Unknown error (10004)
Update-processing thread finishing
Deregistered connection from app
Checking tray icon
Exiting
Deleting tray icon
VNC viewer closing down

Could it have something to do with cached files from my previous testing attempts?

Maybe someone knows what the "Unknown Error" is...

redge · Post by **redge** » 2005-05-27 21:21

what style of your connection ?

LAN <--> LAN
WLAN <--> LAN
WLAN <--> WLAN
WAN <--> Internet <---> WAN

iamchris · Post by **iamchris** » 2005-05-31 12:44

what style of your connection ?

LAN <--> LAN
WLAN <--> LAN
WLAN <--> WLAN
WAN <--> Internet <---> WAN

Given the choices from above I would say it is

WAN <--> Internet <---> WAN

However, the network connectivity doesn't seem to be the deciding factor. Originating from the same remote LAN, connecting to my Viewer (running Windows XP), a Windows 2000 workstation connects flawlessly, and a WindowsXP Professional workstation exhibits the "Unknown Error" crash.

iamchris · Post by **iamchris** » 2005-06-01 19:21

Here's some more info...

The viewer is the 206 (fixed) version, although it reports 204 in the "About" dialog. I've tried many combinations of server and viewer.

I can't figure out how to make winvnc record a log on the remote side. That functionality doesn't seem to be available in the SC version. Logging from DSM is a snap if I can control the environment variables. There's nothing different of consequence in the remote DSM logs.

Rebooting is always #1 on my troubleshoot list. It had no effect. As I monitor my resources in real-time on my local PC, it appears that there's no starvation going on.

Network topology:

Client <--> Switch <--> Firewall (with Generic Service Proxy) <--> Router <--> (internet) <--> (who knows what ...) <--> Client

Network topology doesn't seem to have an effect on the problem. Both connections over my lan and connections to a remote lan fail. Also, I can utilize a non-encrypted connection without problem both an local and remote connections. Additionally, this problem does not occur on Windows 2000 Pro, yet if fails on Windows XP Pro.

The _only_ combination I have found to work with rc4 encryption is SC 20 and VncViewer RC18. Thes keeps me from being able to do remote support for Windows98'ers. VncViewer 203, 205 and 206 don't work with SC20. SC 203 + any version of VncViewer crashes when encryption is turned on.

I really think there's a problem here.

Please advise! Thanks!