SSO Fails If Attach Message Does Not Contain LUWID or Other Subfield (313202)



The information in this article applies to:

  • Microsoft SNA Server 4.0
  • Microsoft SNA Server 4.0 SP1
  • Microsoft SNA Server 4.0 SP2
  • Microsoft SNA Server 4.0 SP3
  • Microsoft SNA Server 4.0 SP4
  • Microsoft Host Integration Server 2000

This article was previously published under Q313202

SYMPTOMS

Advanced Program-to-Program Communications (APPC) or Common Programming Interface for Communications (CPI-C) applications that are configured to use the Single Sign-On (SSO) feature may fail to connect to a host system if the FMH-5 (function management header) Attach message does not contain one or more of the following subfields:
  • Logical Unit of Work Identifier (LUWID) subfield
  • Conversation Correlator field
  • Password subfield (a subfield in the Access Security Information subfield, which also ordinarily includes a User ID subfield)

CAUSE

The SNA Server service (Snaservr.exe) fails to correctly parse short FMH-5 Attach messages. The FMH-5 Attach messages are short because they lack one or more subfields.

RESOLUTION

SNA Server 4.0

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft SNA Server version 4.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix should have the following file attributes or later:

File nameDateTime
Snaservr.exe07-December-20017:50 A.M.

NOTE: Because of file dependencies, the most recent fix that contains the preceding files may also contain additional files.

Host Integration Server 2000

No fix is available for this problem in Host Integration Server 2000 at this time.

STATUS

SNA Server 4.0

Microsoft has confirmed that this is a problem in SNA Server versions 4.0, 4.0 Service Pack (SP) 1, 4.0 SP2, 4.0 SP3, and 4.0 SP4.

Host Integration Server 2000

Microsoft has confirmed that this is a problem in Host Integration Server 2000.

MORE INFORMATION

The following are configuration settings that result in an FMH-5 Attach message that does not include one or more of the necessary fields:
  • If the APPC or CPI-C application is running on an SNA Server 4.0 client or SNA Server 4.0 system that is configured with registry entry LUWIDSUP=NO, the APPC dynamic link library (DLL) will not ask the SNA Server service to generate an LUWID. The resulting FMH-5 Attach message will not include the Logical Unit of Work Identifier subfield.
  • If an APPC or CPI-C application is designed to use a security type of AP_SAME or CM_SECURITY_SAME, the FMH-5 Attach message may not include the password subfield as part of the Access Security Information subfield.
For more information on these and other fields and parameters that are included in FMH-5 Attach messages, see "FM Headers" in the IBM SNA Formats guide (GA27-3136).

Modification Type:MinorLast Reviewed:10/6/2005
Keywords:kbBug kbfix kbQFE KB313202