LDAP authentication with just sAMAccountName

["Florea, Cosmin Petre" <fosminclorea@gmail.com>]

Hello,

I have a LDAP Linux  client written with OpenLDAP and i need it to be 
able to authenticate a user only by username and password (no domain). 
By username i mean the sAMAccountName from the LDAP record. The bind 
succeeds  if i use "username@domain" or if i use the userPrincipalName 
(which is not equal to  sAMAccountName), but i am unable to make it work 
just with username. Anonymous ldap_bind followed by a ldap_search does 
not work (it works if the bind is not anonymous).

I have also a windows client (not using openldap library) implemented 
with DirectoryEntry from C#. The login with just the username works fine 
in that implementation (connected to the same LDAP server). In the LDAP 
log file on Windows i see (i put [...] to hide the server address):

        <Data Name="Message">ldap_bind called for connection 
0xd059b718: DN is (null). Method is 0x486. Synchronous is 0x1.
        <Data Name="Message">ldapBind found server is Windows 2003 or 
better AD on connection 0xd059b718
        <Data Name="Message">Connection-&gt;hostname is 
&apos;[.........]&apos;
        <Data Name="Message">Connection-&gt;DnsSuppliedNAme is 
&apos;[.........]&apos;
        <Data Name="Message">Connection-&gt;DomainName is 
&apos;(null)&apos;
        <Data Name="Message">LDAP: make spn returned 
&apos;ldap/[.........]&apos; with error 0
        <Data Name="Message">ldapBind found GSSAPI auth type on 
connection 0xd059b718
        <Data Name="Message">ldapBind found GSS-SPNEGO auth type on 
connection 0xd059b718
        <Data Name="Message">ldapBind found DIGEST auth type on 
connection 0xd059b718
        <Data Name="Message">ldap bind: Server is v3
        <Data Name="Message">ldap bind: Server supports both GSS-SPNEGO 
and GSSAPI
        <Data Name="Message">New servicename for bind is 
&apos;ldap/[.........]&apos;
        <Data Name="Message">wldap32:Server is capable of &apos;NTLM&apos;
        <Data Name="Message">ldap_bind returned 0x0 for connection 
0xd059b718.

So on windows it does ldap_bind 2 times , but i think it is using a 
different mechanism, probably Windows specific (i mean not ldap_search) 
to retrieve the userPrincipalName associated with the sAMAccountName 
from input.

I do not have an account that i can use to make the initial bind (my 
client should work with several distinct servers). My question is: how 
to do it  on linux with OpenLDAP? Is it possible?

Thank you.