I am trying to enable Windows Authentication on a remote Firebird 2.5 database. I modified the Firebird config file and changed the authentication method to 'MIXED', restarted the Firebird services but so far have still not been able to use Windows credentials. Is there additional steps to get this working?

1 Answer 1


Few basic things things to check -

  • Check user name length. Like in few other databases, this could be failing if the Windows user name length is greater than the permitted limit. From FireBird's documentation this seems to be 31.
  • Try using Trusted mode and if needed enforce Windows authentication.

Is this a web application connecting which is connecting to this database? If so what's the browser being currently used.

  • Thank you for the pointers. The qualified name being used to authenticate is only 15 characters and yes, Trusted mode has been tried and yields to the same error. What does enforcing Windows authentication mean and how is it done? I just recently downloaded Firebird and I see the same message when I atttempt to connect to the same server.
    – dbakuno
    Nov 9, 2016 at 23:56
  • The error message is: Engine Error (code 335544472) with message 'Your username and password are not defined ... ' and SQL Error code = -902. which I have looked up in the Firebird book of error codes, I still don't have a clue what to do.
    – dbakuno
    Nov 10, 2016 at 0:04
  • Firebird documentation for forcing trusted authentication - firebirdsql.org/rlsnotesh/rnfb210-wintrusted.html.
    – thinkster
    Nov 10, 2016 at 13:46
  • The error code implies that a valid login has not been configured. Is the Firebird database on a Windows server? I assume you have full rights to install and configure databases.
    – thinkster
    Nov 10, 2016 at 13:46
  • Thank you @thinkster. Yes, the server is on Windows and the user I am using is an Administrator to the machine with full privileges.
    – dbakuno
    Nov 11, 2016 at 0:46

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