Windows 95 RPC Ignores Shutdown Packets

• Microsoft Windows 95

SYMPTOMS

When you are running a program using RPC in Windows 95, the program may report a packet integrity error or security interface error when the program receives a "Shutdown" packet from the RPC server.

This error is most likely to occur with a program that uses the Microsoft Security Support Provider interface, and to be reported as a security validation error.

CAUSE

The RPC run-time library in Windows 95 ignores Shutdown packets, instead of destroying the session and incrementing the received packet count as expected.

RESOLUTION

This issue is resolved by the following updated file for Windows 95, and later versions of this file:

   RPCLTC3.DLL  version 4.00.951  dated 1/24/96  7,568 bytes 

STATUS

Microsoft has confirmed this to be a problem in Microsoft Windows 95. An update to address this problem is now available, but is not fully regression tested and should be applied only to computers experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft does not recommend implementing this update at this time. Contact Microsoft Technical Support for additional information about the availability of this update.

This issue is resolved in Microsoft Windows 98.

MORE INFORMATION

Shutdown packets are specified in the Open Software Foundation (OSF) Distribution Computing Environment (DCE) specification, which defines the industry standard for implementing remote procedure calls (RPC). A DCE- compliant RPC client is expected to terminate the RPC session when it receives a Shutdown packet. In Windows 95, the RPC run-time library does not terminate the session when a Shutdown packet is received.

Also, the received packet count is not properly incremented when a Shut- down packet is received. The received packet count (MessageSequenceNumber counter) is used to calculate and validate checksums for programs that use the Microsoft Security Support Provider interface. The RPC run-time library does not calculate checksums correctly because of this error, and checksum validation can fail when called later.

Microsoft RPC run-time libraries do not generate Shutdown packets. Only non-Microsoft DCE servers (such as Unix servers) generate Shutdown packets.

For additional information about issues resolved by updates to this component, please see the following article in the Microsoft Knowledge Base:

Q149846 RPC Program Fails When Server Run Down Occurs

Q161020 Implementing Windows 95 Updates

Keywords : kbnetwork kbpolicy win95 kbRPC kbSDKPlatform kbGrpNet
Version : 95
Platform : WINDOWS
Issue type : kbprb