krb5_check_clockskew
ret = krb5_check_clockskew(context, ts->patimestamp);
retval = krb5_check_clockskew(context, pa_enc->patimestamp);
ret = krb5_check_clockskew(context, rdata->timestamp);
if ((retval = krb5_check_clockskew(context, (*auth_context)->authentp->ctime)))
retval = krb5_check_clockskew(ctx, ts);
retval = krb5_check_clockskew(ctx, et->patimestamp);
retval = krb5_check_clockskew(context, pka->ctime);