use_conf_ktypes

[Mike Patnode]

Can someone explain the thinking behind use_conf_ktypes?  I'm trying to
eliminate the repeated parsing of krb5.conf on every ticket request by
configuring my context appropriately, and found the code doesn't want me
to do that.   Here from init_ctx.c: krb5_get_tgs_ktypes()

 

    if (context->use_conf_ktypes)

        /* This one is set *only* by reading the config file; it's not

           set by the application.  */

        return(get_profile_etype_list(context, ktypes,
"default_tgs_enctypes",

                                      0, NULL));

    else

        return(get_profile_etype_list(context, ktypes,
"default_tgs_enctypes",

                                      context->tgs_ktype_count,

                                      context->tgs_ktypes));

 

Then in krb5_fwd_tgt_creds():

 

    /* fetch tgt directly from cache */

    context->use_conf_ktypes = 1;

    retval = krb5_cc_retrieve_cred (context, cc,
KRB5_TC_SUPPORTED_KTYPES,

                    &creds, &tgt);

    context->use_conf_ktypes = old_use_conf_ktypes;

 

 

Why in this case is it necessary to ignore the application's supported
encryption type list?