To use a default credential when initiating a security context, an application calls the gss_init_sec_context( ) routine and specifies GSS_C_NO_CREDENTIAL as the input claimant credential handle to the routine. The routine uses the initiator's DCE default login context to generate the default credential. The credential is an INITIATE type credential.
You can change the default login context by calling the DCE sec_login_*( ) routines. For information on these routines, see the appropriate sec_login_*(3sec) reference page.