derive_wbytes
ret = derive_wbytes(context, ch->group, st->initial_key, &wbytes);
ret = derive_wbytes(context, group, ikey, &wbytes);
ret = derive_wbytes(context, group, ikey, &wbytes);
check(derive_wbytes(ctx, t->group, ikey, &wbytes));
krb5_error_code derive_wbytes(krb5_context context, int32_t group,