1.2.0.0 Plugin Problems

[mag]

I am trying this with a desktop and laptop side by side on the same network. The program works fine when not using the DSM plugin.

Both XP systems are using identical UltraVNC 1.0.2 distributions (verified by hash comparison). I'm just running from the program, not as a service.

I copied the MSRC4Plugin.dsm file from the plugins dir to the program directory on both machines. I generated a key on one of them, renamed it to rc4.key, and copied it over to the other machine. The keys are in the same directory as the program in both cases.

In the program options, the plugin is checked and selected. Clicking the options button shows that the key has been found in both instances. A VNC password is set on the server.

I've tried doing this both ways, with the two computers switching roles as client and server, but cannot connect. The following error appears:

Connection failed - Invalid protocol !

Possible causes:

- You've forgotten to select a DSMPlugin and the Server uses a DSMPlugin
- The selected DSMPlugin is not compatible with the one running on the Server
- The selected DSMPlugin is not correctly configured (also possibly on the Server)
- The password you've possibly entered is incorrect

In both cases I am not prompted for the server password. The status area says "Negotiate Protocol Version..."

I've tried enabling logging both of the normal server and the DSM logging and have not found anything that shows a plugin error, just a normal client disconnected message.

Any help on this would be greatly appreciated. Thanks

[redge]

How do you use encryption with vncviewer ?
suggest you copy your command line here

[scovel]

Re-start the service.

[mag]

I'm just using the GUI option for DSM in the viewer.

It is not running as a service.

[scovel]

The server end must be running as a service, right? Did you install the plugin and the key on the server end over a VNC connection? Reset the server service and you should be all set.

Sean

[mag]

No, it is not running as a service. It's running a user instance from the GUI. In any case, I've reset the server a few times and nothing helps.

[redge]

you can try without rc4.key at both side (vncviewer + winvnc)
because you have set a vnc password to vnc server
and use MSRC4Plugin_noreg.dsm 1.2.0 at both side (not search trough registry for find the rc4.key)

if this work without rc4.key, Maybe a corrupted key container
The tool for fix key containers KeyPal

[redge]

UltraVNC 1.0.2 (vncviewer + winvnc as application)
MSRC4Plugin_noreg.dsm 1.2.0.0
MSRC4plugin.dsm 1.2.0.0
all test without rc4.key

remember:
VNC password <=8 digits
(do no input more than 8 aphadigits otherwise always fail authentication with dsmplugin

unsuccessful with MSRC4Plugin at vncviewer and MSRC4Plugin_NoReg at winvnc
unsuccessful with MSRC4Plugin_noreg at vncviewer and MSRC4Plugin at winvnc

successful with MSRC4Plugin.dsm at both side
successful with MSRC4Plugin_noreg.dsm at both side

[redge]

XP Home SP2 LAN 100 Mbits/s <---> LAN 100 Mbits/s XP Professional SP2
UltraVNC 1.0.2 (vncviewer + winvnc as application)
MSRC4Plugin_noreg.dsm 1.2.0.0
MSRC4plugin.dsm 1.2.0.0
all test with rc4.key



VNC password and dsmplugin
<= 8 digits (authentication success with and without dsmplugin)
> 8 digits
without dsmplugin (exceed digits are just ignored and authentication success
with dsmplugin, do no input more than 8 aphadigits otherwise, authentication always fail


successful with MSRC4Plugin at vncviewer and MSRC4Plugin_NoReg at winvnc
successful with MSRC4Plugin_noreg at vncviewer and MSRC4Plugin at winvnc
successful with MSRC4Plugin.dsm at both side
successful with MSRC4Plugin_noreg.dsm at both side

[mag]

removing the key file from both ends did the trick

what's the purpose of the key then?

[scovel]

The plugin can be used with a pre-shared 128 bit random key. That is what is in the key file.

Historically this was the only way it worked. It used the key as the session key to encrypt the data. Since there is no mechanism in the DSM architecture to exchange keys, that was a way to get around it. At that point using the password only was a security risk since it is only 8 characters (less than 128 bits!).

Recently I added a way for the plugins to exchange some "randomness" and to use the password, the "randomness" (Initial Vector), and a hash to generate a more secure 128 bit session key from the password. Now the plugin can use a key, or not. Your choice.

Sounds like your keys didn't match?

Sean

[mag]

nope, they were identical (hashed them to be sure)

thanks

[scovel]

You are NOT making this easy!

No idea. Glad its working for you now. (Hope this doesn't come up again....)

Sean

[redge]

what's the purpose of the key then?

2 purposes

• for travelling and limited access to registry or read only.
  vncviewer+rc4.key+msrc4plugin_noreg.dsm on USB storage
• for SingleClick (SC) cannot use password not existing due reverse connection and need the key.
  otherwise, without rc4.key msrc4plugin ask password and authentication always fail.

[Arnie_75]

Is connecting via KEY more secure?

[scovel]

See this topic for more details [topic=6708][/topic]

Short answer, a little, because the key has more bits than the password can.

Key = 128 Bits
Password = 64 Bits

Both are hashed into a 128 Bit session key.

Sean

[StealthyC]

You are NOT making this easy!

No idea. Glad its working for you now. (Hope this doesn't come up again....)

Sean

Getting the same problem as posted above

Connection failed - Invalid protocol !

Possible causes:

- You've forgotten to select a DSMPlugin and the Server uses a DSMPlugin
- The selected DSMPlugin is not compatible with the one running on the Server
- The selected DSMPlugin is not correctly configured (also possibly on the Server)
- The password you've possibly entered is incorrect

Both with reg and no reg dsm.

Exact key on both ends, smae plugin as well.

[redge]

Getting the same problem as posted above

[topic=7123][/topic]

[redge]

[topic=7420][/topic]
Removed SALT for Windows 2000 bug.