GSSAPI authentication

Hello all

We are running Postgres 14 on Ubuntu. Our Windows users connect passwordless using GSSAPI. This works great.

Now we want users on Linux client to also connect passwordless using GSSAPI. Users on Linux log on using their Active Directory credentials, as the Linux host (Ubuntu 22.04) is joined to the domain. Logon to Linux works fine, access to Windows cifs shares works fine authentication with Kerberos.

But psql won't connect using GSSAPI. It does hit the right pg_hba.conf line and the username is translated via pg_ident.conf, just fine. But psql says

psql: error: connection to server at "srvpostgres4.xxx.local" (172.30.33.30), port 1609 failed: could not initiate GSSAPI security context: Unspecified GSS failure. Minor code may provide more information: Server not found in Kerberos database connection to server at "srvpostgres4.xxx.local" (172.30.33.30), port 1609 failed: GSSAPI continuation error: Unspecified GSS failure. Minor code may provide more information: Server not found in Kerberos database

Server log is like this

2022-06-06 08:14:01.176 CEST,"yyy","db1",474094,"172.30.32.213:33556",627e83c9.73bee,2,"authentication",2022-06-06 08:14:01 CEST,2/14544,0,FATAL,28000,"GSSAPI authentication failed for user ""yyy""","Connection matched pg_hba.conf line 15: ""host all all 172.0.0.0/8 gss map=xxxlocal include_realm=0 krb_realm=""XXX.LOCAL""""",,,,,,,,"","client backend",,-3382135431624836920

We are a bit lost here. What are we missing?

Regards Niels Jespersen