s3:utils: let smbstatus report anonymous signing/encryption explicitly
[samba.git] / source4 / auth / kerberos / krb5_init_context.c
index e3479b12d190d1a836b66dd5e3f2535221119599..0eb849c4ce0d171545676e738726c1377bddbcf0 100644 (file)
@@ -1,4 +1,4 @@
-/* 
+/*
    Unix SMB/CIFS implementation.
    Wrapper for krb5_init_context
 
    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 "system/kerberos.h"
-#include "heimdal/lib/krb5/krb5_locl.h"
+#include <tevent.h>
 #include "auth/kerberos/kerberos.h"
 #include "lib/socket/socket.h"
 #include "lib/stream/packet.h"
 #include "system/network.h"
-#include "lib/events/events.h"
-#include "roken.h"
 #include "param/param.h"
+#include "libcli/resolve/resolve.h"
+#include "../lib/tsocket/tsocket.h"
+#include "krb5_init_context.h"
+#ifdef SAMBA4_USES_HEIMDAL
+#include "../lib/dbwrap/dbwrap.h"
+#include "../lib/dbwrap/dbwrap_rbt.h"
+#include "../lib/util/util_tdb.h"
+#include <krb5/send_to_kdc_plugin.h>
+#endif
 
 /*
   context structure for operations on cldap packets
@@ -38,43 +45,53 @@ struct smb_krb5_socket {
        struct socket_context *sock;
 
        /* the fd event */
-       struct fd_event *fde;
+       struct tevent_fd *fde;
 
        NTSTATUS status;
        DATA_BLOB request, reply;
-       
+
        struct packet_context *packet;
 
        size_t partial_read;
-
+#ifdef SAMBA4_USES_HEIMDAL
        krb5_krbhst_info *hi;
+#endif
 };
 
-static int smb_krb5_context_destroy_1(struct smb_krb5_context *ctx)
+static krb5_error_code smb_krb5_context_destroy(struct smb_krb5_context *ctx)
 {
-       krb5_free_context(ctx->krb5_context); 
-       return 0;
-}
-
-static int smb_krb5_context_destroy_2(struct smb_krb5_context *ctx)
-{
-       /* Otherwise krb5_free_context will try and close what we have already free()ed */
-       krb5_set_warn_dest(ctx->krb5_context, NULL);
-       krb5_closelog(ctx->krb5_context, ctx->logf);
-       smb_krb5_context_destroy_1(ctx);
+#ifdef SAMBA4_USES_HEIMDAL
+       if (ctx->pvt_log_data) {
+               /* Otherwise krb5_free_context will try and close what we
+                * have already free()ed */
+               krb5_set_warn_dest(ctx->krb5_context, NULL);
+               krb5_closelog(ctx->krb5_context,
+                               (krb5_log_facility *)ctx->pvt_log_data);
+       }
+#endif
+       krb5_free_context(ctx->krb5_context);
        return 0;
 }
 
+#ifdef SAMBA4_USES_HEIMDAL
 /* We never close down the DEBUG system, and no need to unreference the use */
-static void smb_krb5_debug_close(void *private) {
+static void smb_krb5_debug_close(void *private_data) {
        return;
 }
+#endif
 
-static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private) 
+#ifdef SAMBA4_USES_HEIMDAL
+static void smb_krb5_debug_wrapper(
+#ifdef HAVE_KRB5_ADDLOG_FUNC_NEED_CONTEXT
+               krb5_context ctx,
+#endif /* HAVE_KRB5_ADDLOG_FUNC_NEED_CONTEXT */
+               const char *timestr, const char *msg, void *private_data)
 {
-       DEBUG(2, ("Kerberos: %s\n", msg));
+       DEBUGC(DBGC_KERBEROS, 3, ("Kerberos: %s\n", msg));
 }
+#endif
 
+#ifdef SAMBA4_USES_HEIMDAL
 /*
   handle recv events on a smb_krb5 socket
 */
@@ -89,38 +106,38 @@ static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
                talloc_free(tmp_ctx);
                return;
        }
-       
+
        blob = data_blob_talloc(tmp_ctx, NULL, dsize);
        if (blob.data == NULL && dsize != 0) {
                smb_krb5->status = NT_STATUS_NO_MEMORY;
                talloc_free(tmp_ctx);
                return;
        }
-       
+
        smb_krb5->status = socket_recv(smb_krb5->sock, blob.data, blob.length, &nread);
        if (!NT_STATUS_IS_OK(smb_krb5->status)) {
                talloc_free(tmp_ctx);
                return;
        }
        blob.length = nread;
-       
+
        if (nread == 0) {
                smb_krb5->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
                talloc_free(tmp_ctx);
                return;
        }
-       
-       DEBUG(2,("Received smb_krb5 packet of length %d\n", 
+
+       DEBUG(4,("Received smb_krb5 packet of length %d\n",
                 (int)blob.length));
-       
+
        talloc_steal(smb_krb5, blob.data);
        smb_krb5->reply = blob;
        talloc_free(tmp_ctx);
 }
 
-static NTSTATUS smb_krb5_full_packet(void *private, DATA_BLOB data) 
+static NTSTATUS smb_krb5_full_packet(void *private_data, DATA_BLOB data)
 {
-       struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
+       struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
        talloc_steal(smb_krb5, data.data);
        smb_krb5->reply = data;
        smb_krb5->reply.length -= 4;
@@ -131,18 +148,18 @@ static NTSTATUS smb_krb5_full_packet(void *private, DATA_BLOB data)
 /*
   handle request timeouts
 */
-static void smb_krb5_request_timeout(struct event_context *event_ctx, 
-                                 struct timed_event *te, struct timeval t,
-                                 void *private)
+static void smb_krb5_request_timeout(struct tevent_context *event_ctx,
+                                 struct tevent_timer *te, struct timeval t,
+                                 void *private_data)
 {
-       struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
+       struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
        DEBUG(5,("Timed out smb_krb5 packet\n"));
        smb_krb5->status = NT_STATUS_IO_TIMEOUT;
 }
 
-static void smb_krb5_error_handler(void *private, NTSTATUS status) 
+static void smb_krb5_error_handler(void *private_data, NTSTATUS status)
 {
-       struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
+       struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
        smb_krb5->status = status;
 }
 
@@ -154,15 +171,15 @@ static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
        NTSTATUS status;
 
        size_t len;
-       
+
        len = smb_krb5->request.length;
        status = socket_send(smb_krb5->sock, &smb_krb5->request, &len);
 
        if (!NT_STATUS_IS_OK(status)) return;
-       
-       EVENT_FD_READABLE(smb_krb5->fde);
 
-       EVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
+       TEVENT_FD_READABLE(smb_krb5->fde);
+
+       TEVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
        return;
 }
 
@@ -170,28 +187,28 @@ static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
 /*
   handle fd events on a smb_krb5_socket
 */
-static void smb_krb5_socket_handler(struct event_context *ev, struct fd_event *fde,
-                                uint16_t flags, void *private)
+static void smb_krb5_socket_handler(struct tevent_context *ev, struct tevent_fd *fde,
+                                uint16_t flags, void *private_data)
 {
-       struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
+       struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
        switch (smb_krb5->hi->proto) {
        case KRB5_KRBHST_UDP:
-               if (flags & EVENT_FD_READ) {
+               if (flags & TEVENT_FD_READ) {
                        smb_krb5_socket_recv(smb_krb5);
                        return;
                }
-               if (flags & EVENT_FD_WRITE) {
+               if (flags & TEVENT_FD_WRITE) {
                        smb_krb5_socket_send(smb_krb5);
                        return;
                }
                /* not reached */
                return;
        case KRB5_KRBHST_TCP:
-               if (flags & EVENT_FD_READ) {
+               if (flags & TEVENT_FD_READ) {
                        packet_recv(smb_krb5->packet);
                        return;
                }
-               if (flags & EVENT_FD_WRITE) {
+               if (flags & TEVENT_FD_WRITE) {
                        packet_queue_run(smb_krb5->packet);
                        return;
                }
@@ -203,36 +220,40 @@ static void smb_krb5_socket_handler(struct event_context *ev, struct fd_event *f
        }
 }
 
-
-krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
-                                           void *data,
-                                           krb5_krbhst_info *hi,
-                                           const krb5_data *send_buf,
-                                           krb5_data *recv_buf)
+static krb5_error_code smb_krb5_send_and_recv_func_int(struct smb_krb5_context *smb_krb5_context,
+                                                      struct tevent_context *ev,
+                                                      krb5_krbhst_info *hi,
+                                                      struct addrinfo *ai,
+                                                      smb_krb5_send_to_kdc_func func,
+                                                      void *data,
+                                                      time_t timeout,
+                                                      const krb5_data *send_buf,
+                                                      krb5_data *recv_buf)
 {
        krb5_error_code ret;
        NTSTATUS status;
-       struct socket_address *remote_addr;
        const char *name;
-       struct addrinfo *ai, *a;
+       struct addrinfo *a;
        struct smb_krb5_socket *smb_krb5;
 
-       struct event_context *ev = talloc_get_type(data, struct event_context);
-
-       DATA_BLOB send_blob = data_blob_const(send_buf->data, send_buf->length);
+       DATA_BLOB send_blob;
 
-       ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
-       if (ret) {
-               return ret;
+       TALLOC_CTX *frame = talloc_stackframe();
+       if (frame == NULL) {
+               return ENOMEM;
        }
 
-       for (a = ai; a; a = ai->ai_next) {
-               smb_krb5 = talloc(NULL, struct smb_krb5_socket);
+       send_blob = data_blob_const(send_buf->data, send_buf->length);
+
+       for (a = ai; a; a = a->ai_next) {
+               struct socket_address *remote_addr;
+               smb_krb5 = talloc(frame, struct smb_krb5_socket);
                if (!smb_krb5) {
+                       TALLOC_FREE(frame);
                        return ENOMEM;
                }
                smb_krb5->hi = hi;
-               
+
                switch (a->ai_family) {
                case PF_INET:
                        name = "ipv4";
@@ -243,24 +264,24 @@ krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
                        break;
 #endif
                default:
-                       talloc_free(smb_krb5);
+                       TALLOC_FREE(frame);
                        return EINVAL;
                }
-               
+
                status = NT_STATUS_INVALID_PARAMETER;
                switch (hi->proto) {
                case KRB5_KRBHST_UDP:
-                       if (lp_parm_bool(global_loadparm, NULL, "krb5", "udp", true)) {
-                               status = socket_create(name, SOCKET_TYPE_DGRAM, &smb_krb5->sock, 0);
-                       }
+                       status = socket_create(smb_krb5, name,
+                                              SOCKET_TYPE_DGRAM,
+                                              &smb_krb5->sock, 0);
                        break;
                case KRB5_KRBHST_TCP:
-                       if (lp_parm_bool(global_loadparm, NULL, "krb5", "tcp", true)) {
-                               status = socket_create(name, SOCKET_TYPE_STREAM, &smb_krb5->sock, 0);
-                       }
+                       status = socket_create(smb_krb5, name,
+                                              SOCKET_TYPE_STREAM,
+                                              &smb_krb5->sock, 0);
                        break;
                case KRB5_KRBHST_HTTP:
-                       talloc_free(smb_krb5);
+                       TALLOC_FREE(frame);
                        return EINVAL;
                }
                if (!NT_STATUS_IS_OK(status)) {
@@ -268,45 +289,41 @@ krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
                        continue;
                }
 
-               talloc_steal(smb_krb5, smb_krb5->sock);
-               
-               remote_addr = socket_address_from_sockaddr(smb_krb5, a->ai_addr, a->ai_addrlen); 
+               remote_addr = socket_address_from_sockaddr(smb_krb5, a->ai_addr, a->ai_addrlen);
                if (!remote_addr) {
                        talloc_free(smb_krb5);
                        continue;
                }
 
-               status = socket_connect_ev(smb_krb5->sock, NULL, remote_addr, 0, 
-                                          lp_name_resolve_order(global_loadparm), ev); 
+               status = socket_connect_ev(smb_krb5->sock, NULL, remote_addr, 0, ev);
                if (!NT_STATUS_IS_OK(status)) {
                        talloc_free(smb_krb5);
                        continue;
                }
-               talloc_free(remote_addr);
 
                /* Setup the FDE, start listening for read events
                 * from the start (otherwise we may miss a socket
                 * drop) and mark as AUTOCLOSE along with the fde */
 
-               /* Ths is equivilant to EVENT_FD_READABLE(smb_krb5->fde) */
-               smb_krb5->fde = event_add_fd(ev, smb_krb5->sock, 
-                                            socket_get_fd(smb_krb5->sock), 
-                                            EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
-                                            smb_krb5_socket_handler, smb_krb5);
+               /* This is equivalent to EVENT_FD_READABLE(smb_krb5->fde) */
+               smb_krb5->fde = tevent_add_fd(ev, smb_krb5->sock,
+                                             socket_get_fd(smb_krb5->sock),
+                                             TEVENT_FD_READ,
+                                             smb_krb5_socket_handler, smb_krb5);
                /* its now the job of the event layer to close the socket */
+               tevent_fd_set_close_fn(smb_krb5->fde, socket_tevent_fd_close_fn);
                socket_set_flags(smb_krb5->sock, SOCKET_FLAG_NOCLOSE);
 
-               event_add_timed(ev, smb_krb5, 
-                               timeval_current_ofs(context->kdc_timeout, 0),
-                               smb_krb5_request_timeout, smb_krb5);
+               tevent_add_timer(ev, smb_krb5,
+                                timeval_current_ofs(timeout, 0),
+                                smb_krb5_request_timeout, smb_krb5);
 
-               
                smb_krb5->status = NT_STATUS_OK;
                smb_krb5->reply = data_blob(NULL, 0);
 
                switch (hi->proto) {
                case KRB5_KRBHST_UDP:
-                       EVENT_FD_WRITEABLE(smb_krb5->fde);
+                       TEVENT_FD_WRITEABLE(smb_krb5->fde);
                        smb_krb5->request = send_blob;
                        break;
                case KRB5_KRBHST_TCP:
@@ -330,14 +347,31 @@ krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
                        packet_send(smb_krb5->packet, smb_krb5->request);
                        break;
                case KRB5_KRBHST_HTTP:
-                       talloc_free(smb_krb5);
+                       TALLOC_FREE(frame);
                        return EINVAL;
                }
                while ((NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
-                       if (event_loop_once(ev) != 0) {
-                               talloc_free(smb_krb5);
+                       if (tevent_loop_once(ev) != 0) {
+                               TALLOC_FREE(frame);
                                return EINVAL;
                        }
+
+                        if (func) {
+                               /* After each and every event loop, reset the
+                                * send_to_kdc pointers to what they were when
+                                * we entered this loop.  That way, if a
+                                * nested event has invalidated them, we put
+                                * it back before we return to the heimdal
+                                * code */
+                               ret = smb_krb5_set_send_to_kdc_func(smb_krb5_context,
+                                                                   NULL, /* send_to_realm */
+                                                                   func,
+                                                                   data);
+                               if (ret != 0) {
+                                       TALLOC_FREE(frame);
+                                       return ret;
+                               }
+                       }
                }
                if (NT_STATUS_EQUAL(smb_krb5->status, NT_STATUS_IO_TIMEOUT)) {
                        talloc_free(smb_krb5);
@@ -345,138 +379,503 @@ krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
                }
 
                if (!NT_STATUS_IS_OK(smb_krb5->status)) {
-                       DEBUG(2,("Error reading smb_krb5 reply packet: %s\n", nt_errstr(smb_krb5->status)));
+                       struct tsocket_address *addr = socket_address_to_tsocket_address(smb_krb5, remote_addr);
+                       const char *addr_string = NULL;
+                       if (addr) {
+                               addr_string = tsocket_address_inet_addr_string(addr, smb_krb5);
+                       } else {
+                               addr_string = NULL;
+                       }
+                       DEBUG(2,("Error reading smb_krb5 reply packet: %s from %s\n", nt_errstr(smb_krb5->status),
+                                addr_string));
                        talloc_free(smb_krb5);
                        continue;
                }
 
                ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
                if (ret) {
-                       talloc_free(smb_krb5);
+                       TALLOC_FREE(frame);
                        return ret;
                }
                talloc_free(smb_krb5);
-               
+
                break;
        }
+       TALLOC_FREE(frame);
        if (a) {
                return 0;
        }
        return KRB5_KDC_UNREACH;
 }
 
-krb5_error_code smb_krb5_init_context(void *parent_ctx, 
-                                     struct event_context *ev,
-                                     struct loadparm_context *lp_ctx,
-                                      struct smb_krb5_context **smb_krb5_context) 
+krb5_error_code smb_krb5_send_and_recv_func(struct smb_krb5_context *smb_krb5_context,
+                                           void *data,
+                                           krb5_krbhst_info *hi,
+                                           time_t timeout,
+                                           const krb5_data *send_buf,
+                                           krb5_data *recv_buf)
 {
        krb5_error_code ret;
-       TALLOC_CTX *tmp_ctx;
-       char **config_files;
-       const char *config_file;
-       
-       initialize_krb5_error_table();
-       
-       tmp_ctx = talloc_new(parent_ctx);
-       *smb_krb5_context = talloc(tmp_ctx, struct smb_krb5_context);
+       struct addrinfo *ai;
 
-       if (!*smb_krb5_context || !tmp_ctx) {
-               talloc_free(tmp_ctx);
+       struct tevent_context *ev;
+       TALLOC_CTX *frame = talloc_stackframe();
+       if (frame == NULL) {
                return ENOMEM;
        }
 
-       ret = krb5_init_context(&(*smb_krb5_context)->krb5_context);
+       if (data == NULL) {
+               /* If no event context was available, then create one for this loop */
+               ev = samba_tevent_context_init(frame);
+               if (ev == NULL) {
+                       TALLOC_FREE(frame);
+                       return ENOMEM;
+               }
+       } else {
+               ev = talloc_get_type_abort(data, struct tevent_context);
+       }
+
+       ret = krb5_krbhst_get_addrinfo(smb_krb5_context->krb5_context, hi, &ai);
        if (ret) {
-               DEBUG(1,("krb5_init_context failed (%s)\n", 
-                        error_message(ret)));
-               talloc_free(tmp_ctx);
+               TALLOC_FREE(frame);
                return ret;
        }
 
-       talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_1);
+       ret = smb_krb5_send_and_recv_func_int(smb_krb5_context,
+                                             ev, hi, ai,
+                                             smb_krb5_send_and_recv_func,
+                                             data, timeout, send_buf, recv_buf);
+       TALLOC_FREE(frame);
+       return ret;
+}
+
+krb5_error_code smb_krb5_send_and_recv_func_forced_tcp(struct smb_krb5_context *smb_krb5_context,
+                                                      struct addrinfo *ai,
+                                                      time_t timeout,
+                                                      const krb5_data *send_buf,
+                                                      krb5_data *recv_buf)
+{
+       krb5_error_code k5ret;
+       krb5_krbhst_info hi = {
+               .proto = KRB5_KRBHST_TCP,
+       };
+       struct tevent_context *ev;
+       TALLOC_CTX *frame = talloc_stackframe();
+       if (frame == NULL) {
+               return ENOMEM;
+       }
+
+       /* no event context is passed in, create one for this loop */
+       ev = samba_tevent_context_init(frame);
+       if (ev == NULL) {
+               TALLOC_FREE(frame);
+               return ENOMEM;
+       }
+
+       /* No need to pass in send_and_recv functions, we won't nest on this private event loop */
+       k5ret = smb_krb5_send_and_recv_func_int(smb_krb5_context, ev, &hi, ai, NULL, NULL,
+                                               timeout, send_buf, recv_buf);
+       TALLOC_FREE(frame);
+       return k5ret;
+}
+
+static struct db_context *smb_krb5_plugin_db;
+
+struct smb_krb5_send_to_kdc_state {
+       intptr_t key_ptr;
+       struct smb_krb5_context *smb_krb5_context;
+       smb_krb5_send_to_realm_func send_to_realm;
+       smb_krb5_send_to_kdc_func send_to_kdc;
+       void *private_data;
+};
+
+static int smb_krb5_send_to_kdc_state_destructor(struct smb_krb5_send_to_kdc_state *state)
+{
+       TDB_DATA key = make_tdb_data((uint8_t *)&state->key_ptr, sizeof(state->key_ptr));
+       NTSTATUS status;
+
+       status = dbwrap_delete(smb_krb5_plugin_db, key);
+       if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
+               status = NT_STATUS_OK;
+       }
+       if (!NT_STATUS_IS_OK(status)) {
+               return -1;
+       }
+
+       state->smb_krb5_context = NULL;
+       return 0;
+}
+
+krb5_error_code smb_krb5_set_send_to_kdc_func(struct smb_krb5_context *smb_krb5_context,
+                                             smb_krb5_send_to_realm_func send_to_realm,
+                                             smb_krb5_send_to_kdc_func send_to_kdc,
+                                             void *private_data)
+{
+       intptr_t key_ptr = (intptr_t)smb_krb5_context->krb5_context;
+       TDB_DATA key = make_tdb_data((uint8_t *)&key_ptr, sizeof(key_ptr));
+       intptr_t value_ptr = (intptr_t)NULL;
+       TDB_DATA value = make_tdb_data(NULL, 0);
+       struct db_record *rec = NULL;
+       struct smb_krb5_send_to_kdc_state *state = NULL;
+       NTSTATUS status;
+
+       rec = dbwrap_fetch_locked(smb_krb5_plugin_db, smb_krb5_context, key);
+       if (rec == NULL) {
+               return ENOMEM;
+       }
+
+       value = dbwrap_record_get_value(rec);
+       if (value.dsize != 0) {
+               SMB_ASSERT(value.dsize == sizeof(value_ptr));
+               memcpy(&value_ptr, value.dptr, sizeof(value_ptr));
+               state = talloc_get_type_abort((const void *)value_ptr,
+                                             struct smb_krb5_send_to_kdc_state);
+               if (send_to_realm == NULL && send_to_kdc == NULL) {
+                       status = dbwrap_record_delete(rec);
+                       TALLOC_FREE(rec);
+                       if (!NT_STATUS_IS_OK(status)) {
+                               return EINVAL;
+                       }
+                       return 0;
+               }
+               state->send_to_realm = send_to_realm;
+               state->send_to_kdc = send_to_kdc;
+               state->private_data = private_data;
+               TALLOC_FREE(rec);
+               return 0;
+       }
+
+       if (send_to_kdc == NULL && send_to_realm == NULL) {
+               TALLOC_FREE(rec);
+               return 0;
+       }
+
+       state = talloc_zero(smb_krb5_context,
+                           struct smb_krb5_send_to_kdc_state);
+       if (state == NULL) {
+               TALLOC_FREE(rec);
+               return ENOMEM;
+       }
+       state->key_ptr = key_ptr;
+       state->smb_krb5_context = smb_krb5_context;
+       state->send_to_realm = send_to_realm;
+       state->send_to_kdc = send_to_kdc;
+       state->private_data = private_data;
+
+       value_ptr = (intptr_t)state;
+       value = make_tdb_data((uint8_t *)&value_ptr, sizeof(value_ptr));
+
+       status = dbwrap_record_store(rec, value, TDB_INSERT);
+       TALLOC_FREE(rec);
+       if (!NT_STATUS_IS_OK(status)) {
+               return EINVAL;
+       }
+       talloc_set_destructor(state, smb_krb5_send_to_kdc_state_destructor);
+
+       return 0;
+}
+
+static krb5_error_code smb_krb5_plugin_init(krb5_context context, void **pctx)
+{
+       *pctx = NULL;
+       return 0;
+}
+
+static void smb_krb5_plugin_fini(void *ctx)
+{
+}
+
+static void smb_krb5_send_to_kdc_state_parser(TDB_DATA key, TDB_DATA value,
+                                             void *private_data)
+{
+       struct smb_krb5_send_to_kdc_state **state =
+               (struct smb_krb5_send_to_kdc_state **)private_data;
+       intptr_t value_ptr;
+
+       SMB_ASSERT(value.dsize == sizeof(value_ptr));
+       memcpy(&value_ptr, value.dptr, sizeof(value_ptr));
+       *state = talloc_get_type_abort((const void *)value_ptr,
+                                      struct smb_krb5_send_to_kdc_state);
+}
+
+static struct smb_krb5_send_to_kdc_state *
+smb_krb5_send_to_kdc_get_state(krb5_context context)
+{
+       intptr_t key_ptr = (intptr_t)context;
+       TDB_DATA key = make_tdb_data((uint8_t *)&key_ptr, sizeof(key_ptr));
+       struct smb_krb5_send_to_kdc_state *state = NULL;
+       NTSTATUS status;
+
+       status = dbwrap_parse_record(smb_krb5_plugin_db, key,
+                                    smb_krb5_send_to_kdc_state_parser,
+                                    &state);
+       if (!NT_STATUS_IS_OK(status)) {
+               return NULL;
+       }
+
+       return state;
+}
+
+static krb5_error_code smb_krb5_plugin_send_to_kdc(krb5_context context,
+                                                  void *ctx,
+                                                  krb5_krbhst_info *ho,
+                                                  time_t timeout,
+                                                  const krb5_data *in,
+                                                  krb5_data *out)
+{
+       struct smb_krb5_send_to_kdc_state *state = NULL;
+
+       state = smb_krb5_send_to_kdc_get_state(context);
+       if (state == NULL) {
+               return KRB5_PLUGIN_NO_HANDLE;
+       }
+
+       if (state->send_to_kdc == NULL) {
+               return KRB5_PLUGIN_NO_HANDLE;
+       }
+
+       return state->send_to_kdc(state->smb_krb5_context,
+                                 state->private_data,
+                                 ho, timeout, in, out);
+}
+
+static krb5_error_code smb_krb5_plugin_send_to_realm(krb5_context context,
+                                                    void *ctx,
+                                                    krb5_const_realm realm,
+                                                    time_t timeout,
+                                                    const krb5_data *in,
+                                                    krb5_data *out)
+{
+       struct smb_krb5_send_to_kdc_state *state = NULL;
+
+       state = smb_krb5_send_to_kdc_get_state(context);
+       if (state == NULL) {
+               return KRB5_PLUGIN_NO_HANDLE;
+       }
+
+       if (state->send_to_realm == NULL) {
+               return KRB5_PLUGIN_NO_HANDLE;
+       }
+
+       return state->send_to_realm(state->smb_krb5_context,
+                                   state->private_data,
+                                   realm, timeout, in, out);
+}
+
+static krb5plugin_send_to_kdc_ftable smb_krb5_plugin_ftable = {
+       KRB5_PLUGIN_SEND_TO_KDC_VERSION_2,
+       smb_krb5_plugin_init,
+       smb_krb5_plugin_fini,
+       smb_krb5_plugin_send_to_kdc,
+       smb_krb5_plugin_send_to_realm
+};
+#endif
+
+krb5_error_code
+smb_krb5_init_context_basic(TALLOC_CTX *tmp_ctx,
+                           struct loadparm_context *lp_ctx,
+                           krb5_context *_krb5_context)
+{
+       krb5_error_code ret;
+#ifdef SAMBA4_USES_HEIMDAL
+       char **config_files;
+       const char *config_file, *realm;
+#endif
+       krb5_context krb5_ctx;
+
+       ret = smb_krb5_init_context_common(&krb5_ctx);
+       if (ret) {
+               return ret;
+       }
 
-       config_file = config_path(tmp_ctx, lp_ctx, "krb5.conf");
+       /* The MIT Kerberos build relies on using the system krb5.conf file.
+        * If you really want to use another file please set KRB5_CONFIG
+        * accordingly. */
+#ifdef SAMBA4_USES_HEIMDAL
+       config_file = lpcfg_config_path(tmp_ctx, lp_ctx, "krb5.conf");
        if (!config_file) {
-               talloc_free(tmp_ctx);
+               krb5_free_context(krb5_ctx);
                return ENOMEM;
        }
-               
+
        /* Use our local krb5.conf file by default */
        ret = krb5_prepend_config_files_default(config_file, &config_files);
        if (ret) {
-               DEBUG(1,("krb5_prepend_config_files_default failed (%s)\n", 
-                        smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
-               talloc_free(tmp_ctx);
+               DEBUG(1,("krb5_prepend_config_files_default failed (%s)\n",
+                        smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
+               krb5_free_context(krb5_ctx);
                return ret;
        }
 
-       ret = krb5_set_config_files((*smb_krb5_context)->krb5_context, 
-                                   config_files);
+       ret = krb5_set_config_files(krb5_ctx, config_files);
        krb5_free_config_files(config_files);
        if (ret) {
-               DEBUG(1,("krb5_set_config_files failed (%s)\n", 
-                        smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
-               talloc_free(tmp_ctx);
+               DEBUG(1,("krb5_set_config_files failed (%s)\n",
+                        smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
+               krb5_free_context(krb5_ctx);
                return ret;
        }
-                                               
-       if (lp_realm(lp_ctx) && *lp_realm(lp_ctx)) {
-               char *upper_realm = strupper_talloc(tmp_ctx, lp_realm(lp_ctx));
-               if (!upper_realm) {
-                       DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm(lp_ctx)));
-                       talloc_free(tmp_ctx);
-                       return ENOMEM;
+
+       /*
+        * This is already called in smb_krb5_init_context_common(),
+        * but krb5_set_config_files() may resets it.
+        */
+       krb5_set_dns_canonicalize_hostname(krb5_ctx, false);
+
+       realm = lpcfg_realm(lp_ctx);
+       if (realm != NULL) {
+               ret = krb5_set_default_realm(krb5_ctx, realm);
+               if (ret) {
+                       DEBUG(1,("krb5_set_default_realm failed (%s)\n",
+                                smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
+                       krb5_free_context(krb5_ctx);
+                       return ret;
                }
-               ret = krb5_set_default_realm((*smb_krb5_context)->krb5_context, upper_realm);
+       }
+
+       if (smb_krb5_plugin_db == NULL) {
+               /*
+                * while krb5_plugin_register() takes a krb5_context,
+                * plugins are registered into a global list, so
+                * we only do that once
+                *
+                * We maintain a separate dispatch table for per
+                * krb5_context state.
+                */
+               ret = krb5_plugin_register(krb5_ctx, PLUGIN_TYPE_DATA,
+                                    KRB5_PLUGIN_SEND_TO_KDC,
+                                    &smb_krb5_plugin_ftable);
                if (ret) {
-                       DEBUG(1,("krb5_set_default_realm failed (%s)\n", 
-                                smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
-                       talloc_free(tmp_ctx);
+                       DEBUG(1,("krb5_plugin_register(KRB5_PLUGIN_SEND_TO_KDC) failed (%s)\n",
+                                smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
+                       krb5_free_context(krb5_ctx);
                        return ret;
                }
+               smb_krb5_plugin_db = db_open_rbt(NULL);
+               if (smb_krb5_plugin_db == NULL) {
+                       DEBUG(1,("db_open_rbt() failed\n"));
+                       krb5_free_context(krb5_ctx);
+                       return ENOMEM;
+               }
        }
+#endif
+       *_krb5_context = krb5_ctx;
+       return 0;
+}
 
-       /* TODO: Should we have a different name here? */
-       ret = krb5_initlog((*smb_krb5_context)->krb5_context, "Samba", &(*smb_krb5_context)->logf);
-       
+krb5_error_code smb_krb5_init_context(void *parent_ctx,
+                                     struct loadparm_context *lp_ctx,
+                                     struct smb_krb5_context **smb_krb5_context)
+{
+       krb5_error_code ret;
+       TALLOC_CTX *tmp_ctx;
+       krb5_context kctx;
+#ifdef SAMBA4_USES_HEIMDAL
+       krb5_log_facility *logf;
+#endif
+
+       tmp_ctx = talloc_new(parent_ctx);
+       *smb_krb5_context = talloc_zero(tmp_ctx, struct smb_krb5_context);
+
+       if (!*smb_krb5_context || !tmp_ctx) {
+               talloc_free(tmp_ctx);
+               return ENOMEM;
+       }
+
+       ret = smb_krb5_init_context_basic(tmp_ctx, lp_ctx, &kctx);
        if (ret) {
-               DEBUG(1,("krb5_initlog failed (%s)\n", 
-                        smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
+               DEBUG(1,("smb_krb5_context_init_basic failed (%s)\n",
+                        error_message(ret)));
                talloc_free(tmp_ctx);
                return ret;
        }
+       (*smb_krb5_context)->krb5_context = kctx;
+
+       talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy);
 
-       talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_2);
+#ifdef SAMBA4_USES_HEIMDAL
+       /* TODO: Should we have a different name here? */
+       ret = krb5_initlog(kctx, "Samba", &logf);
 
-       ret = krb5_addlog_func((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf, 0 /* min */, -1 /* max */, 
-                              smb_krb5_debug_wrapper, smb_krb5_debug_close, NULL);
        if (ret) {
-               DEBUG(1,("krb5_addlog_func failed (%s)\n", 
-                        smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
+               DEBUG(1,("krb5_initlog failed (%s)\n",
+                        smb_get_krb5_error_message(kctx, ret, tmp_ctx)));
                talloc_free(tmp_ctx);
                return ret;
        }
-       krb5_set_warn_dest((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf);
+       (*smb_krb5_context)->pvt_log_data = logf;
 
-       /* Set use of our socket lib */
-       ret = krb5_set_send_to_kdc_func((*smb_krb5_context)->krb5_context, 
-                                       smb_krb5_send_and_recv_func, 
-                                       ev);
+       ret = krb5_addlog_func(kctx, logf, 0 /* min */, -1 /* max */,
+                              smb_krb5_debug_wrapper,
+                               smb_krb5_debug_close, NULL);
        if (ret) {
-               DEBUG(1,("krb5_set_send_recv_func failed (%s)\n", 
-                        smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
+               DEBUG(1,("krb5_addlog_func failed (%s)\n",
+                        smb_get_krb5_error_message(kctx, ret, tmp_ctx)));
                talloc_free(tmp_ctx);
                return ret;
        }
-
+       krb5_set_warn_dest(kctx, logf);
+#endif
        talloc_steal(parent_ctx, *smb_krb5_context);
        talloc_free(tmp_ctx);
 
-       /* Set options in kerberos */
+       return 0;
+}
 
-       krb5_set_dns_canonicalize_hostname((*smb_krb5_context)->krb5_context,
-                                          lp_parm_bool(lp_ctx, NULL, "krb5", "set_dns_canonicalize", false));
+#ifdef SAMBA4_USES_HEIMDAL
+krb5_error_code smb_krb5_context_set_event_ctx(struct smb_krb5_context *smb_krb5_context,
+                                              struct tevent_context *ev,
+                                              struct tevent_context **previous_ev)
+{
+       int ret;
+       if (!ev) {
+               return EINVAL;
+       }
+
+       *previous_ev = smb_krb5_context->current_ev;
+
+       smb_krb5_context->current_ev = talloc_reference(smb_krb5_context, ev);
+       if (!smb_krb5_context->current_ev) {
+               return ENOMEM;
+       }
 
+       /* Set use of our socket lib */
+       ret = smb_krb5_set_send_to_kdc_func(smb_krb5_context,
+                                           NULL, /* send_to_realm */
+                                           smb_krb5_send_and_recv_func,
+                                           ev);
+       if (ret) {
+               TALLOC_CTX *tmp_ctx = talloc_new(NULL);
+               DEBUG(1,("smb_krb5_set_send_recv_func failed (%s)\n",
+                        smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, tmp_ctx)));
+               talloc_free(tmp_ctx);
+               talloc_unlink(smb_krb5_context, smb_krb5_context->current_ev);
+               smb_krb5_context->current_ev = NULL;
+               return ret;
+       }
        return 0;
 }
 
+krb5_error_code smb_krb5_context_remove_event_ctx(struct smb_krb5_context *smb_krb5_context,
+                                                 struct tevent_context *previous_ev,
+                                                 struct tevent_context *ev)
+{
+       int ret;
+       talloc_unlink(smb_krb5_context, ev);
+       /* If there was a mismatch with things happening on a stack, then don't wipe things */
+       smb_krb5_context->current_ev = previous_ev;
+       /* Set use of our socket lib */
+       ret = smb_krb5_set_send_to_kdc_func(smb_krb5_context,
+                                           NULL, /* send_to_realm */
+                                           smb_krb5_send_and_recv_func,
+                                           previous_ev);
+       if (ret) {
+               TALLOC_CTX *tmp_ctx = talloc_new(NULL);
+               DEBUG(1,("smb_krb5_set_send_recv_func failed (%s)\n",
+                        smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, tmp_ctx)));
+               talloc_free(tmp_ctx);
+               return ret;
+       }
+       return 0;
+}
+#endif