G *req,
                                                 const X509_NAME *issuer,
                                                 const ASN1_INTEGER *serial);
 typedef int (*OSSL_CMP_SRV_genm_cb_t)(OSSL_CMP_SRV_CTX *srv_ctx,
                                       const OSSL_CMP_MSG *req,
                                       STACK_OF(OSSL_CMP_ITAV) *in,
                                       STACK_OF(OSSL_CMP_ITAV) **out);
 typedef void (*OSSL_CMP_SRV_error_cb_t)(OSSL_CMP_SRV_CTX *srv_ctx,
               