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OS Authentication Fails With ORA-12638 On Non-English Windows System (Doc ID 1280996.1)

Last updated on AUGUST 17, 2022

Applies to:

Oracle Database - Enterprise Edition - Version and later
Oracle Database Cloud Schema Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Generic Windows


- You are running Oracle on a Windows system with an non-English language (typically French, but may happen with other languages)
- sqlnet.ora parameter sqlnet.authentication_services = (NTS) for Active Directory authentication.
- The Oracle services run with the local system account (default)
- The Domain user is properly added to the local ORA_DBA group.
- When you try to connect with a Domain user it fails with the error ORA-12638

Advanced Symptoms:

When you trace the connection using sqlnet tracing at level 16, the following two additional symptoms can be observed in the client side trace file:

- There's a special character in the packet that contains the username received by the client:

[11-JANV.-2011 14:43:08:370] nsprecv: 15 00 00 47 52 4F 55 50 |...GROUP|
[11-JANV.-2011 14:43:08:370] nsprecv: 45 42 41 54 54 45 55 52 |<USERNAME>|
[11-JANV.-2011 14:43:08:370] nsprecv: 5C 53 79 73 74 E8 6D 65 |\|

- Further down in the trace file the following errors are recorded also:

[11-JANV.-2011 14:43:08:370] naun5authent: Authentication type is 0
[11-JANV.-2011 14:43:08:370] naun5authent: SSPI: 0x80090303 error in InitializeSecurityContext
[11-JANV.-2011 14:43:08:370] naun5authent: exit
[11-JANV.-2011 14:43:08:370] naunauthent: exit
[11-JANV.-2011 14:43:08:370] nau_ccn: get credentials function failed
[11-JANV.-2011 14:43:08:370] nau_ccn: failed with error 12638


So far this is observed with Oracle 11.2 on Windows systems configured with the French language, the Oracle service is running with the local system account.


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