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IT22990: CHLAUTH rule fails to be applied as expected however error AMQ9557 reports 'User ID' in different case

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APAR status

  • Closed as program error.

Error description

  • If a user ID is flowed to MQ using a UserID structure, rather
    than an MQCSP structure, then any CHLAUTH rules applied prior to
    user adoption will evaluate the user ID in the case it is
    presented in the UserID structure.
    CHLAUTH rules which do not match the case of this user ID will
    not be applied.
    Despite this, the user ID printed in the AMQ9557 diagnostic
    message did not report the user ID in the case in which it was

Local fix

  • Verify user id case from client and ensure CHLAUTH rule uses
    same case.  Often userIDs from Windows platforms are flowed to
    the queue manager in upper case.

Problem summary

  • ****************************************************************
    This issue affects users of CHLAUTH rules which perform user
    mapping who provide user credentials using a userID flow. This
    includes users of compatibility mode for authentication in the
    MQ classes for Java, MQ classes for JMS or MQ Explorer.
    The issue is not observed if CHLAUTH early adopt is enabled.
    Platforms affected:
    There was no functional defect, however there was an difficulty
    troubleshooting this problem, because MQ does not report errors
    or warnings if a particular CHLAUTH rule could not be applied.
    In this case AMQ9557 does not report anything about the CHLAUTH
    rule that could not be applied, but it reports problem with the
    remote user id which is unable to connect to the queue manager.
    Error message:
      AMQ9557: Queue Manager User ID initialization failed for
    AMQ9557 error message prints 'user123' (in lowercase), however
    the actual client user id was 'USER123'.  AMQ9557 prints user id
    in lower case, because when a user is received by UNIX and Linux
    systems, the content of the LongMCAUserIdentifier field that is
    received from the client is changed to lowercase.
    This isuse was more often seen with Windows client application
    connecting to a Unix queue manager in since the user ID from
    Windows mostly comes in upper case.

Problem conclusion

  • MQ code has been modified to improve AMQ9557 error message,
    which will now additionally report the UserID in the case in
    which it was received, if a UserID flow is used.
    The fix is targeted for delivery in the following PTFs:
    Version    Maintenance Level
    v9.1 CD    9.1.3
    v9.1 LTS
    The latest available maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    If the maintenance level is not yet available information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'

Temporary fix


APAR Information

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  • Reported component ID


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  • PE




  • Special Attention

    NoSpecatt / Xsystem

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Fix information

  • Fixed component name


  • Fixed component ID


Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SS5K6E","label":"IBM MQ Appliance"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"901","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
28 February 2019