int serialize_spkm3_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf);
int serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf);
int serialize_spkm3_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf);
int serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf);