krb5_derive_Ke
int krb5_derive_Ke(const struct krb5_enctype *krb5, const struct krb5_buffer *TK,
ret = krb5_derive_Ke(krb5, TK, usage, &Ke, gfp);
ret = krb5_derive_Ke(krb5, base_key, test->use, &result, GFP_KERNEL);