dprov_ctx_dual_t
(((dprov_ctx_dual_t *)(_ctx)->cc_provider_private)->cd_cipher_ctx)
(((dprov_ctx_dual_t *)(_ctx)->cc_provider_private)->cd_mac_ctx)
dprov_private = kmem_zalloc(sizeof (dprov_ctx_dual_t),
kmem_free(ctx_single, sizeof (dprov_ctx_dual_t));