CVE-2021-3738 s4:rpc_server/samr: make use of dcesrv_samdb_connect_as_*() helper
This avoids a crash that's triggered by windows clients using
handles from samr_Connect*() on across multiple connections within
an association group.
In other cases is not strictly required, but it makes it easier to audit that
source4/rpc_server no longer calls samdb_connect() directly and also
improves the auditing for the dcesrv_samdb_connect_as_system() case.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14468
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
[abartlet@samba.org Backported from master as Samba 4.13 does not
call dcerpc_is_transport_encrypted() and so session_info becomes
unused.]