Stuck with kerberos authentication to Sharepoint

I have to connect to MS IIS server using SPNEGO token with Kerberos ticket inside, exactly as Internet Explorer does it.

If I use java GSSManager.initiateContext() it does request tickets with incorrect KDCOptions, dates and some other params I cannot control.

I tried com.dstc.security lib, and was able to get tickets axactly as Internet Explorer with couple of lines:

prepare required KDCOptions;
Credential tgt = kerberos.requestTicketGrantingTicket(new KerberosPassword(password.getBytes()), kdo, new Date(), d, new InetAddress[] {InetAddress.getByName("somename")}, null);
Credential srvt = kerberos.requestServiceTicket(TGT, new PrincipalName(2, "HTTP/server.domain.net"), REALM, kdo);

But how can I use these credentials or tickets inside to create SPNEGO token same as I can get with GSSManager.initiateContext()?