XIMS: AUTH LOGIN Command Must Use Base-64-Encoded User Name and Password

ID: Q235627

The information in this article applies to:
IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SUMMARY

Microsoft Exchange Server 5.5 supports the AUTH LOGIN command for clear text authentication using a base-64-encoded user name and password. It does not accept the AUTH LOGIN command if the user name and password are in an X.500 Distinguished Name (DN) format. If the AUTH LOGIN command is sent in this manner, the following event may appear in the event log on the Exchange Server computer, indicating that the authentication attempt was not successful:

Event ID: 4183
Description: Authentication attempt (AUTH LOGIN) from hostname as username failed: LogonUser() call failed with error: Logon failure: unknown user name or bad password.
Note that when responding to an EHLO command, Exchange Server always indicates that it supports the AUTH LOGIN command.


MORE INFORMATION

Microsoft recognizes the fact that some e-mail clients and servers send the AUTH LOGIN command with a user name and password in an X.500 DN format. We have modified the Internet Mail Service so it can be configured to behave in the following manner:

This supported feature is now available from Microsoft, but has not been fully regression tested and should be applied only to systems having a specific need for it. If you are not severely affected by the lack of this feature, Microsoft recommends that you wait for the next Microsoft Exchange Server version 5.5 service pack that contains this feature.

To obtain this feature immediately, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:
http://www.microsoft.com/support/supportnet/overview/overview.asp
The English version of this feature should have the following file attributes or later:

Component: Internet Mail Service

File name Version
Imcmsg.dll 5.5.2638.0
Msexcimc.exe 5.5.2638.0

This hotfix has been posted to the following Internet location as Psp2imca.zip and Psp2imci.zip:
ftp://ftp.microsoft.com/bussys/exchange/exchange-public/fixes/Eng/Exchg5.5/PostSP2/imc-fix

NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this feature, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this feature, and if it is determined that you only require the feature you requested, no fee will be charged. However, if you request additional technical support, and if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support, you may be charged a non-refundable fee.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:
Q154871 Determining If You Are Eligible for No-Charge Technical Support
After you obtain this feature, to modify the behavior of the Internet Mail Service:

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).
  1. Start Registry Editor (Regedt32.exe).


  2. Locate the following key in the registry:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIMC\Parameters
    NOTE: The above registry key is one path; it has been wrapped for readability.


  3. On the Edit menu, click Add Value, and then add the following registry value:


    4. Value Name: DisableAuth
    Data Type: REG_DWORD
    Value: 1 (or any other non-zero value)
  4. Quit Registry Editor.


Additional query words: fail 


Keywords          : exc55 
Version           : winnt:5.5
Platform          : winnt 
Issue type        : kbinfo

Last Reviewed: August 2, 1999