/* Unix SMB/CIFS implementation. KDC Server startup Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2008 Copyright (C) Andrew Tridgell 2005 Copyright (C) Stefan Metzmacher 2005 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "includes.h" #include "smbd/service_task.h" #include "smbd/service.h" #include "smbd/service_stream.h" #include "smbd/process_model.h" #include "lib/events/events.h" #include "lib/socket/socket.h" #include "system/network.h" #include "../lib/util/dlinklist.h" #include "lib/messaging/irpc.h" #include "lib/stream/packet.h" #include "librpc/gen_ndr/samr.h" #include "librpc/gen_ndr/ndr_irpc.h" #include "librpc/gen_ndr/ndr_krb5pac.h" #include "lib/socket/netif.h" #include "param/param.h" #include "kdc/kdc.h" #include "librpc/gen_ndr/ndr_misc.h" /* Disgusting hack to get a mem_ctx and lp_ctx into the hdb plugin, when * used as a keytab */ TALLOC_CTX *hdb_samba4_mem_ctx; struct tevent_context *hdb_samba4_ev_ctx; struct loadparm_context *hdb_samba4_lp_ctx; /* hold all the info needed to send a reply */ struct kdc_reply { struct kdc_reply *next, *prev; struct socket_address *dest; DATA_BLOB packet; }; typedef bool (*kdc_process_fn_t)(struct kdc_server *kdc, TALLOC_CTX *mem_ctx, DATA_BLOB *input, DATA_BLOB *reply, struct socket_address *peer_addr, struct socket_address *my_addr, int datagram); /* hold information about one kdc socket */ struct kdc_socket { struct socket_context *sock; struct kdc_server *kdc; struct tevent_fd *fde; /* a queue of outgoing replies that have been deferred */ struct kdc_reply *send_queue; kdc_process_fn_t process; }; /* state of an open tcp connection */ struct kdc_tcp_connection { /* stream connection we belong to */ struct stream_connection *conn; /* the kdc_server the connection belongs to */ struct kdc_server *kdc; struct packet_context *packet; kdc_process_fn_t process; }; /* handle fd send events on a KDC socket */ static void kdc_send_handler(struct kdc_socket *kdc_socket) { while (kdc_socket->send_queue) { struct kdc_reply *rep = kdc_socket->send_queue; NTSTATUS status; size_t sendlen; status = socket_sendto(kdc_socket->sock, &rep->packet, &sendlen, rep->dest); if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) { break; } if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_BUFFER_SIZE)) { /* Replace with a krb err, response to big */ } DLIST_REMOVE(kdc_socket->send_queue, rep); talloc_free(rep); } if (kdc_socket->send_queue == NULL) { EVENT_FD_NOT_WRITEABLE(kdc_socket->fde); } } /* handle fd recv events on a KDC socket */ static void kdc_recv_handler(struct kdc_socket *kdc_socket) { NTSTATUS status; TALLOC_CTX *tmp_ctx = talloc_new(kdc_socket); DATA_BLOB blob; struct kdc_reply *rep; DATA_BLOB reply; size_t nread, dsize; struct socket_address *src; struct socket_address *my_addr; int ret; status = socket_pending(kdc_socket->sock, &dsize); if (!NT_STATUS_IS_OK(status)) { talloc_free(tmp_ctx); return; } blob = data_blob_talloc(tmp_ctx, NULL, dsize); if (blob.data == NULL) { /* hope this is a temporary low memory condition */ talloc_free(tmp_ctx); return; } status = socket_recvfrom(kdc_socket->sock, blob.data, blob.length, &nread, tmp_ctx, &src); if (!NT_STATUS_IS_OK(status)) { talloc_free(tmp_ctx); return; } blob.length = nread; DEBUG(10,("Received krb5 UDP packet of length %lu from %s:%u\n", (long)blob.length, src->addr, (uint16_t)src->port)); my_addr = socket_get_my_addr(kdc_socket->sock, tmp_ctx); if (!my_addr) { talloc_free(tmp_ctx); return; } /* Call krb5 */ ret = kdc_socket->process(kdc_socket->kdc, tmp_ctx, &blob, &reply, src, my_addr, 1 /* Datagram */); if (!ret) { talloc_free(tmp_ctx); return; } /* queue a pending reply */ rep = talloc(kdc_socket, struct kdc_reply); if (rep == NULL) { talloc_free(tmp_ctx); return; } rep->dest = talloc_steal(rep, src); rep->packet = reply; talloc_steal(rep, reply.data); if (rep->packet.data == NULL) { talloc_free(rep); talloc_free(tmp_ctx); return; } DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *); EVENT_FD_WRITEABLE(kdc_socket->fde); talloc_free(tmp_ctx); } /* handle fd events on a KDC socket */ static void kdc_socket_handler(struct tevent_context *ev, struct tevent_fd *fde, uint16_t flags, void *private_data) { struct kdc_socket *kdc_socket = talloc_get_type(private_data, struct kdc_socket); if (flags & EVENT_FD_WRITE) { kdc_send_handler(kdc_socket); } if (flags & EVENT_FD_READ) { kdc_recv_handler(kdc_socket); } } static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdcconn, const char *reason) { stream_terminate_connection(kdcconn->conn, reason); } /* receive a full packet on a KDC connection */ static NTSTATUS kdc_tcp_recv(void *private_data, DATA_BLOB blob) { struct kdc_tcp_connection *kdcconn = talloc_get_type(private_data, struct kdc_tcp_connection); NTSTATUS status = NT_STATUS_UNSUCCESSFUL; TALLOC_CTX *tmp_ctx = talloc_new(kdcconn); int ret; DATA_BLOB input, reply; struct socket_address *src_addr; struct socket_address *my_addr; talloc_steal(tmp_ctx, blob.data); src_addr = socket_get_peer_addr(kdcconn->conn->socket, tmp_ctx); if (!src_addr) { talloc_free(tmp_ctx); return NT_STATUS_NO_MEMORY; } my_addr = socket_get_my_addr(kdcconn->conn->socket, tmp_ctx); if (!my_addr) { talloc_free(tmp_ctx); return NT_STATUS_NO_MEMORY; } /* Call krb5 */ input = data_blob_const(blob.data + 4, blob.length - 4); ret = kdcconn->process(kdcconn->kdc, tmp_ctx, &input, &reply, src_addr, my_addr, 0 /* Not datagram */); if (!ret) { talloc_free(tmp_ctx); return NT_STATUS_INTERNAL_ERROR; } /* and now encode the reply */ blob = data_blob_talloc(kdcconn, NULL, reply.length + 4); if (!blob.data) { talloc_free(tmp_ctx); return NT_STATUS_NO_MEMORY; } RSIVAL(blob.data, 0, reply.length); memcpy(blob.data + 4, reply.data, reply.length); status = packet_send(kdcconn->packet, blob); if (!NT_STATUS_IS_OK(status)) { talloc_free(tmp_ctx); return status; } /* the call isn't needed any more */ talloc_free(tmp_ctx); return NT_STATUS_OK; } /* receive some data on a KDC connection */ static void kdc_tcp_recv_handler(struct stream_connection *conn, uint16_t flags) { struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data, struct kdc_tcp_connection); packet_recv(kdcconn->packet); } /* called on a tcp recv error */ static void kdc_tcp_recv_error(void *private_data, NTSTATUS status) { struct kdc_tcp_connection *kdcconn = talloc_get_type(private_data, struct kdc_tcp_connection); kdc_tcp_terminate_connection(kdcconn, nt_errstr(status)); } /* called when we can write to a connection */ static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags) { struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data, struct kdc_tcp_connection); packet_queue_run(kdcconn->packet); } /** Wrapper for krb5_kdc_process_krb5_request, converting to/from Samba calling conventions */ static bool kdc_process(struct kdc_server *kdc, TALLOC_CTX *mem_ctx, DATA_BLOB *input, DATA_BLOB *reply, struct socket_address *peer_addr, struct socket_address *my_addr, int datagram_reply) { int ret; krb5_data k5_reply; krb5_data_zero(&k5_reply); krb5_kdc_update_time(NULL); DEBUG(10,("Received KDC packet of length %lu from %s:%d\n", (long)input->length - 4, peer_addr->addr, peer_addr->port)); ret = krb5_kdc_process_krb5_request(kdc->smb_krb5_context->krb5_context, kdc->config, input->data, input->length, &k5_reply, peer_addr->addr, peer_addr->sockaddr, datagram_reply); if (ret == -1) { *reply = data_blob(NULL, 0); return false; } if (k5_reply.length) { *reply = data_blob_talloc(mem_ctx, k5_reply.data, k5_reply.length); krb5_data_free(&k5_reply); } else { *reply = data_blob(NULL, 0); } return true; } /* called when we get a new connection */ static void kdc_tcp_generic_accept(struct stream_connection *conn, kdc_process_fn_t process_fn) { struct kdc_server *kdc = talloc_get_type(conn->private_data, struct kdc_server); struct kdc_tcp_connection *kdcconn; kdcconn = talloc_zero(conn, struct kdc_tcp_connection); if (!kdcconn) { stream_terminate_connection(conn, "kdc_tcp_accept: out of memory"); return; } kdcconn->conn = conn; kdcconn->kdc = kdc; kdcconn->process = process_fn; conn->private_data = kdcconn; kdcconn->packet = packet_init(kdcconn); if (kdcconn->packet == NULL) { kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_accept: out of memory"); return; } packet_set_private(kdcconn->packet, kdcconn); packet_set_socket(kdcconn->packet, conn->socket); packet_set_callback(kdcconn->packet, kdc_tcp_recv); packet_set_full_request(kdcconn->packet, packet_full_request_u32); packet_set_error_handler(kdcconn->packet, kdc_tcp_recv_error); packet_set_event_context(kdcconn->packet, conn->event.ctx); packet_set_fde(kdcconn->packet, conn->event.fde); packet_set_serialise(kdcconn->packet); } static void kdc_tcp_accept(struct stream_connection *conn) { kdc_tcp_generic_accept(conn, kdc_process); } static const struct stream_server_ops kdc_tcp_stream_ops = { .name = "kdc_tcp", .accept_connection = kdc_tcp_accept, .recv_handler = kdc_tcp_recv_handler, .send_handler = kdc_tcp_send }; static void kpasswdd_tcp_accept(struct stream_connection *conn) { kdc_tcp_generic_accept(conn, kpasswdd_process); } static const struct stream_server_ops kpasswdd_tcp_stream_ops = { .name = "kpasswdd_tcp", .accept_connection = kpasswdd_tcp_accept, .recv_handler = kdc_tcp_recv_handler, .send_handler = kdc_tcp_send }; /* start listening on the given address */ static NTSTATUS kdc_add_socket(struct kdc_server *kdc, const char *address, uint16_t kdc_port, uint16_t kpasswd_port) { const struct model_ops *model_ops; struct kdc_socket *kdc_socket; struct kdc_socket *kpasswd_socket; struct socket_address *kdc_address, *kpasswd_address; NTSTATUS status; kdc_socket = talloc(kdc, struct kdc_socket); NT_STATUS_HAVE_NO_MEMORY(kdc_socket); kpasswd_socket = talloc(kdc, struct kdc_socket); NT_STATUS_HAVE_NO_MEMORY(kpasswd_socket); status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0); if (!NT_STATUS_IS_OK(status)) { talloc_free(kdc_socket); return status; } status = socket_create("ip", SOCKET_TYPE_DGRAM, &kpasswd_socket->sock, 0); if (!NT_STATUS_IS_OK(status)) { talloc_free(kpasswd_socket); return status; } kdc_socket->kdc = kdc; kdc_socket->send_queue = NULL; kdc_socket->process = kdc_process; talloc_steal(kdc_socket, kdc_socket->sock); kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc, socket_get_fd(kdc_socket->sock), EVENT_FD_READ, kdc_socket_handler, kdc_socket); kdc_address = socket_address_from_strings(kdc_socket, kdc_socket->sock->backend_name, address, kdc_port); NT_STATUS_HAVE_NO_MEMORY(kdc_address); status = socket_listen(kdc_socket->sock, kdc_address, 0, 0); if (!NT_STATUS_IS_OK(status)) { DEBUG(0,("Failed to bind to %s:%d UDP for kdc - %s\n", address, kdc_port, nt_errstr(status))); talloc_free(kdc_socket); return status; } kpasswd_socket->kdc = kdc; kpasswd_socket->send_queue = NULL; kpasswd_socket->process = kpasswdd_process; talloc_steal(kpasswd_socket, kpasswd_socket->sock); kpasswd_socket->fde = event_add_fd(kdc->task->event_ctx, kdc, socket_get_fd(kpasswd_socket->sock), EVENT_FD_READ, kdc_socket_handler, kpasswd_socket); kpasswd_address = socket_address_from_strings(kpasswd_socket, kpasswd_socket->sock->backend_name, address, kpasswd_port); NT_STATUS_HAVE_NO_MEMORY(kpasswd_address); status = socket_listen(kpasswd_socket->sock, kpasswd_address, 0, 0); if (!NT_STATUS_IS_OK(status)) { DEBUG(0,("Failed to bind to %s:%d UDP for kpasswd - %s\n", address, kpasswd_port, nt_errstr(status))); talloc_free(kpasswd_socket); return status; } /* within the kdc task we want to be a single process, so ask for the single process model ops and pass these to the stream_setup_socket() call. */ model_ops = process_model_startup(kdc->task->event_ctx, "single"); if (!model_ops) { DEBUG(0,("Can't find 'single' process model_ops\n")); talloc_free(kdc_socket); return NT_STATUS_INTERNAL_ERROR; } status = stream_setup_socket(kdc->task->event_ctx, kdc->task->lp_ctx, model_ops, &kdc_tcp_stream_ops, "ip", address, &kdc_port, lp_socket_options(kdc->task->lp_ctx), kdc); if (!NT_STATUS_IS_OK(status)) { DEBUG(0,("Failed to bind to %s:%u TCP - %s\n", address, kdc_port, nt_errstr(status))); talloc_free(kdc_socket); return status; } status = stream_setup_socket(kdc->task->event_ctx, kdc->task->lp_ctx, model_ops, &kpasswdd_tcp_stream_ops, "ip", address, &kpasswd_port, lp_socket_options(kdc->task->lp_ctx), kdc); if (!NT_STATUS_IS_OK(status)) { DEBUG(0,("Failed to bind to %s:%u TCP - %s\n", address, kpasswd_port, nt_errstr(status))); talloc_free(kdc_socket); return status; } return NT_STATUS_OK; } /* setup our listening sockets on the configured network interfaces */ static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc, struct loadparm_context *lp_ctx, struct interface *ifaces) { int num_interfaces; TALLOC_CTX *tmp_ctx = talloc_new(kdc); NTSTATUS status; int i; num_interfaces = iface_count(ifaces); for (i=0; i<num_interfaces; i++) { const char *address = talloc_strdup(tmp_ctx, iface_n_ip(ifaces, i)); status = kdc_add_socket(kdc, address, lp_krb5_port(lp_ctx), lp_kpasswd_port(lp_ctx)); NT_STATUS_NOT_OK_RETURN(status); } talloc_free(tmp_ctx); return NT_STATUS_OK; } static NTSTATUS kdc_check_generic_kerberos(struct irpc_message *msg, struct kdc_check_generic_kerberos *r) { struct PAC_Validate pac_validate; DATA_BLOB srv_sig; struct PAC_SIGNATURE_DATA kdc_sig; struct kdc_server *kdc = talloc_get_type(msg->private_data, struct kdc_server); enum ndr_err_code ndr_err; krb5_enctype etype; int ret; hdb_entry_ex ent; krb5_principal principal; krb5_keyblock keyblock; Key *key; /* There is no reply to this request */ r->out.generic_reply = data_blob(NULL, 0); ndr_err = ndr_pull_struct_blob(&r->in.generic_request, msg, lp_iconv_convenience(kdc->task->lp_ctx), &pac_validate, (ndr_pull_flags_fn_t)ndr_pull_PAC_Validate); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { return NT_STATUS_INVALID_PARAMETER; } if (pac_validate.MessageType != 3) { /* We don't implement any other message types - such as certificate validation - yet */ return NT_STATUS_INVALID_PARAMETER; } if (pac_validate.ChecksumAndSignature.length != (pac_validate.ChecksumLength + pac_validate.SignatureLength) || pac_validate.ChecksumAndSignature.length < pac_validate.ChecksumLength || pac_validate.ChecksumAndSignature.length < pac_validate.SignatureLength ) { return NT_STATUS_INVALID_PARAMETER; } srv_sig = data_blob_const(pac_validate.ChecksumAndSignature.data, pac_validate.ChecksumLength); if (pac_validate.SignatureType == CKSUMTYPE_HMAC_MD5) { etype = ETYPE_ARCFOUR_HMAC_MD5; } else { ret = krb5_cksumtype_to_enctype(kdc->smb_krb5_context->krb5_context, pac_validate.SignatureType, &etype); if (ret != 0) { return NT_STATUS_LOGON_FAILURE; } } ret = krb5_make_principal(kdc->smb_krb5_context->krb5_context, &principal, lp_realm(kdc->task->lp_ctx), "krbtgt", lp_realm(kdc->task->lp_ctx), NULL); if (ret != 0) { return NT_STATUS_NO_MEMORY; } ret = kdc->config->db[0]->hdb_fetch(kdc->smb_krb5_context->krb5_context, kdc->config->db[0], principal, HDB_F_GET_KRBTGT | HDB_F_DECRYPT, &ent); if (ret != 0) { hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent); krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal); return NT_STATUS_LOGON_FAILURE; } ret = hdb_enctype2key(kdc->smb_krb5_context->krb5_context, &ent.entry, etype, &key); if (ret != 0) { hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent); krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal); return NT_STATUS_LOGON_FAILURE; } keyblock = key->key; kdc_sig.type = pac_validate.SignatureType; kdc_sig.signature = data_blob_const(&pac_validate.ChecksumAndSignature.data[pac_validate.ChecksumLength], pac_validate.SignatureLength); ret = check_pac_checksum(msg, srv_sig, &kdc_sig, kdc->smb_krb5_context->krb5_context, &keyblock); hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent); krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal); if (ret != 0) { return NT_STATUS_LOGON_FAILURE; } return NT_STATUS_OK; } /* startup the kdc task */ static void kdc_task_init(struct task_server *task) { struct kdc_server *kdc; NTSTATUS status; krb5_error_code ret; struct interface *ifaces; switch (lp_server_role(task->lp_ctx)) { case ROLE_STANDALONE: task_server_terminate(task, "kdc: no KDC required in standalone configuration"); return; case ROLE_DOMAIN_MEMBER: task_server_terminate(task, "kdc: no KDC required in member server configuration"); return; case ROLE_DOMAIN_CONTROLLER: /* Yes, we want a KDC */ break; } load_interfaces(task, lp_interfaces(task->lp_ctx), &ifaces); if (iface_count(ifaces) == 0) { task_server_terminate(task, "kdc: no network interfaces configured"); return; } task_server_set_title(task, "task[kdc]"); kdc = talloc(task, struct kdc_server); if (kdc == NULL) { task_server_terminate(task, "kdc: out of memory"); return; } kdc->task = task; initialize_krb5_error_table(); ret = smb_krb5_init_context(kdc, task->event_ctx, task->lp_ctx, &kdc->smb_krb5_context); if (ret) { DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n", error_message(ret))); task_server_terminate(task, "kdc: krb5_init_context failed"); return; } krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r); ret = krb5_kdc_get_config(kdc->smb_krb5_context->krb5_context, &kdc->config); if(ret) { task_server_terminate(task, "kdc: failed to get KDC configuration"); return; } kdc->config->logf = kdc->smb_krb5_context->logf; kdc->config->db = talloc(kdc, struct HDB *); if (!kdc->config->db) { task_server_terminate(task, "kdc: out of memory"); return; } kdc->config->num_db = 1; status = hdb_samba4_create_kdc(kdc, task->event_ctx, task->lp_ctx, kdc->smb_krb5_context->krb5_context, &kdc->config->db[0]); if (!NT_STATUS_IS_OK(status)) { task_server_terminate(task, "kdc: hdb_samba4_create_kdc (setup KDC database) failed"); return; } /* Register hdb-samba4 hooks for use as a keytab */ kdc->hdb_samba4_context = talloc(kdc, struct hdb_samba4_context); if (!kdc->hdb_samba4_context) { task_server_terminate(task, "kdc: out of memory"); return; } kdc->hdb_samba4_context->ev_ctx = task->event_ctx; kdc->hdb_samba4_context->lp_ctx = task->lp_ctx; ret = krb5_plugin_register(kdc->smb_krb5_context->krb5_context, PLUGIN_TYPE_DATA, "hdb", &hdb_samba4); if(ret) { task_server_terminate(task, "kdc: failed to register hdb keytab"); return; } ret = krb5_kt_register(kdc->smb_krb5_context->krb5_context, &hdb_kt_ops); if(ret) { task_server_terminate(task, "kdc: failed to register hdb keytab"); return; } /* Registar WinDC hooks */ ret = krb5_plugin_register(kdc->smb_krb5_context->krb5_context, PLUGIN_TYPE_DATA, "windc", &windc_plugin_table); if(ret) { task_server_terminate(task, "kdc: failed to register hdb keytab"); return; } krb5_kdc_windc_init(kdc->smb_krb5_context->krb5_context); /* start listening on the configured network interfaces */ status = kdc_startup_interfaces(kdc, task->lp_ctx, ifaces); if (!NT_STATUS_IS_OK(status)) { task_server_terminate(task, "kdc failed to setup interfaces"); return; } status = IRPC_REGISTER(task->msg_ctx, irpc, KDC_CHECK_GENERIC_KERBEROS, kdc_check_generic_kerberos, kdc); if (!NT_STATUS_IS_OK(status)) { task_server_terminate(task, "nbtd failed to setup monitoring"); return; } irpc_add_name(task->msg_ctx, "kdc_server"); } /* called at smbd startup - register ourselves as a server service */ NTSTATUS server_service_kdc_init(void) { return register_server_service("kdc", kdc_task_init); }