SNA Server 3.0 Windows 95 Clients Hang when Using Encryption

• Microsoft SNA Server version 3.0

SYMPTOMS

Windows 95 SNA Server 3.0 clients appear to stop responding (hang) when they are trying to connect to an SNA Server that exists in a non-trusted Windows NT server domain.

This problem occurs under either of the following conditions:

Case 1: "Use Client/Server Encryption"

   The "Use Client/Server Encryption" option is selected for the configured
   users/groups in SNA Server Manager.

Case 2: "Use Windows NT Domain Password"

   The "Use Windows NT domain password" option is not selected in the
   Windows 95 SNA Server client configuration. This option is available
   by selecting the Advanced tab after running the SNA Client Configuration
   program.

CAUSE

There is a different cause for each condition described in the "Symptoms" section of this article.

Case 1: "Use Client/Server Encryption"

   If Client/Server Encryption is being used, the client/server encryption
   check fails because the client is in a non-trusted domain causing the
   client to hang.

Case 2: "Use Windows NT Domain Password"

   The Windows 95 SNA Server client uses the LsaLogonUser() call when
   attempting to log the user on, even though the "Use Windows NT domain
   password" option is not selected. This was causing the logon attempt to
   fail and this caused the Windows 95 client to hang.

RESOLUTION

Two problems were corrected to resolve the problem.

Case 1: "Use Client/Server Encryption"

   The SNA Server client transports were updated, such that the SNA
   Server client is disconnected if the client/server encryption check
   fails. The updated modules for this fix are:

      <Snaroot>\System\Snaat.dll
      <Snaroot>\System\Snabv.dll
      <Snaroot>\System\Snalm.dll
      <Snaroot>\System\Snalm.dll
      <Snaroot>\System\Snanb.dll
      <Snaroot>\System\Snanw.dll
      <Snaroot>\System\Snadmod.dll
      <Snaroot>\System\Snaevent.dll

Case 2: "Use Windows NT Domain Password"

   The Windows 95 SNA Server 3.0 client has been updated to use the
   NTLM logon process instead of the LsaLogonUser() logon procedure when
   the "Use Windows NT domain password" option is not selected. The updated
   modules for this fix are:

      <Snaroot>\System\Snabase.exe
      <Winroot>\System\Snakrnl.dll

STATUS

Microsoft has confirmed this to be a problem in SNA Server version 3.0. This problem was corrected in the latest Microsoft SNA Server 3.0 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):