Q316683: Cache Expiration Does Not Free All Associated Memory
Article: Q316683
Product(s): Microsoft Windows NT
Version(s): 4.0,4.0 SP6a
Operating System(s):
Keyword(s): kbWinNT400nospFix
Last Modified: 10-JUL-2002
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Windows NT Server versions 4.0, 4.0 SP6a
- Microsoft Windows NT Server, Enterprise Edition versions 4.0, 4.0 SP6a
-------------------------------------------------------------------------------
SYMPTOMS
========
Programs that use cryptographic functions that are provided by Schannel.dll may
show a memory leak. A function that is typically used at the beginning of the
sequence might be the AcquireCredentialsHandle function. Programs that make many
Secure Sockets Layer (SSL) connections rapidly may experience this leak. For
example, Microsoft Exchange 5.5 Service Pack 4 (SP4) experiences this leak.
CAUSE
=====
The problem is caused by the caching mechanism in Schannel.dll. Typically,
credentials are cached for a while in case a client wants to try a reconnection.
Reconnections are effectively a mini-SSL handshake, during which the client uses
the session keys from a previous session.
This behavior occurs when you access Exchange over IMAP4 SSL port 993. Using
IMAP4 port 143, which is not an SSL port, does not show the leak.
RESOLUTION
==========
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 systems
that are experiencing this specific problem.
To resolve this problem, 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:
http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS
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 usual 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:
Date Time Version Size File name
--------------------------------------------------------
09-Jul-2002 20:29 4.87.1964.1878 112,912 Sch128c.dll
09-Jul-2002 20:29 4.86.1964.1878 143,632 Schnlc.dll
NOTE: Because of file dependencies, this hotfix requires Microsoft Windows NT 4.0
Service Pack 6a.
STATUS
======
Microsoft has confirmed that this is a problem in the Microsoft products that
are listed at the beginning of this article.
Additional query words: 2655.68
======================================================================
Keywords : kbWinNT400nospFix
Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400sp6 kbWinNTS400search kbWinNTS400 kbWinNTSEnt400SP6a
Version : :4.0,4.0 SP6a
Hardware : ALPHA x86
Issue type : kbbug
Solution Type : kbfix
=============================================================================
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.
Copyright Microsoft Corporation 1986-2002.