5e771a87cc5cd103b6d0e601633893da4fc300c2
[kai/samba-autobuild/.git] / source4 / auth / kerberos / krb5_init_context.c
1 /*
2    Unix SMB/CIFS implementation.
3    Wrapper for krb5_init_context
4
5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
6    Copyright (C) Andrew Tridgell 2005
7    Copyright (C) Stefan Metzmacher 2004
8
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18
19    You should have received a copy of the GNU General Public License
20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include "includes.h"
24 #include "system/kerberos.h"
25 #include "system/gssapi.h"
26 #include <tevent.h>
27 #include "auth/kerberos/kerberos.h"
28 #include "lib/socket/socket.h"
29 #include "lib/stream/packet.h"
30 #include "system/network.h"
31 #include "param/param.h"
32 #include "libcli/resolve/resolve.h"
33 #include "../lib/tsocket/tsocket.h"
34 #include "krb5_init_context.h"
35 /*
36   context structure for operations on cldap packets
37 */
38 struct smb_krb5_socket {
39         struct socket_context *sock;
40
41         /* the fd event */
42         struct tevent_fd *fde;
43
44         NTSTATUS status;
45         DATA_BLOB request, reply;
46
47         struct packet_context *packet;
48
49         size_t partial_read;
50 #ifdef SAMBA4_USES_HEIMDAL
51         krb5_krbhst_info *hi;
52 #endif
53 };
54
55 static krb5_error_code smb_krb5_context_destroy(struct smb_krb5_context *ctx)
56 {
57 #ifdef SAMBA4_USES_HEIMDAL
58         if (ctx->pvt_log_data) {
59                 /* Otherwise krb5_free_context will try and close what we
60                  * have already free()ed */
61                 krb5_set_warn_dest(ctx->krb5_context, NULL);
62                 krb5_closelog(ctx->krb5_context,
63                                 (krb5_log_facility *)ctx->pvt_log_data);
64         }
65 #endif
66         krb5_free_context(ctx->krb5_context);
67         return 0;
68 }
69
70 #ifdef SAMBA4_USES_HEIMDAL
71 /* We never close down the DEBUG system, and no need to unreference the use */
72 static void smb_krb5_debug_close(void *private_data) {
73         return;
74 }
75 #endif
76
77 #ifdef SAMBA4_USES_HEIMDAL
78 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private_data)
79 {
80         DEBUGC(DBGC_KERBEROS, 3, ("Kerberos: %s\n", msg));
81 }
82 #endif
83
84 #ifdef SAMBA4_USES_HEIMDAL
85 /*
86   handle recv events on a smb_krb5 socket
87 */
88 static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
89 {
90         TALLOC_CTX *tmp_ctx = talloc_new(smb_krb5);
91         DATA_BLOB blob;
92         size_t nread, dsize;
93
94         smb_krb5->status = socket_pending(smb_krb5->sock, &dsize);
95         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
96                 talloc_free(tmp_ctx);
97                 return;
98         }
99
100         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
101         if (blob.data == NULL && dsize != 0) {
102                 smb_krb5->status = NT_STATUS_NO_MEMORY;
103                 talloc_free(tmp_ctx);
104                 return;
105         }
106
107         smb_krb5->status = socket_recv(smb_krb5->sock, blob.data, blob.length, &nread);
108         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
109                 talloc_free(tmp_ctx);
110                 return;
111         }
112         blob.length = nread;
113
114         if (nread == 0) {
115                 smb_krb5->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
116                 talloc_free(tmp_ctx);
117                 return;
118         }
119
120         DEBUG(4,("Received smb_krb5 packet of length %d\n",
121                  (int)blob.length));
122
123         talloc_steal(smb_krb5, blob.data);
124         smb_krb5->reply = blob;
125         talloc_free(tmp_ctx);
126 }
127
128 static NTSTATUS smb_krb5_full_packet(void *private_data, DATA_BLOB data)
129 {
130         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
131         talloc_steal(smb_krb5, data.data);
132         smb_krb5->reply = data;
133         smb_krb5->reply.length -= 4;
134         smb_krb5->reply.data += 4;
135         return NT_STATUS_OK;
136 }
137
138 /*
139   handle request timeouts
140 */
141 static void smb_krb5_request_timeout(struct tevent_context *event_ctx,
142                                   struct tevent_timer *te, struct timeval t,
143                                   void *private_data)
144 {
145         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
146         DEBUG(5,("Timed out smb_krb5 packet\n"));
147         smb_krb5->status = NT_STATUS_IO_TIMEOUT;
148 }
149
150 static void smb_krb5_error_handler(void *private_data, NTSTATUS status)
151 {
152         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
153         smb_krb5->status = status;
154 }
155
156 /*
157   handle send events on a smb_krb5 socket
158 */
159 static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
160 {
161         NTSTATUS status;
162
163         size_t len;
164
165         len = smb_krb5->request.length;
166         status = socket_send(smb_krb5->sock, &smb_krb5->request, &len);
167
168         if (!NT_STATUS_IS_OK(status)) return;
169
170         TEVENT_FD_READABLE(smb_krb5->fde);
171
172         TEVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
173         return;
174 }
175
176
177 /*
178   handle fd events on a smb_krb5_socket
179 */
180 static void smb_krb5_socket_handler(struct tevent_context *ev, struct tevent_fd *fde,
181                                  uint16_t flags, void *private_data)
182 {
183         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
184         switch (smb_krb5->hi->proto) {
185         case KRB5_KRBHST_UDP:
186                 if (flags & TEVENT_FD_READ) {
187                         smb_krb5_socket_recv(smb_krb5);
188                         return;
189                 }
190                 if (flags & TEVENT_FD_WRITE) {
191                         smb_krb5_socket_send(smb_krb5);
192                         return;
193                 }
194                 /* not reached */
195                 return;
196         case KRB5_KRBHST_TCP:
197                 if (flags & TEVENT_FD_READ) {
198                         packet_recv(smb_krb5->packet);
199                         return;
200                 }
201                 if (flags & TEVENT_FD_WRITE) {
202                         packet_queue_run(smb_krb5->packet);
203                         return;
204                 }
205                 /* not reached */
206                 return;
207         case KRB5_KRBHST_HTTP:
208                 /* can't happen */
209                 break;
210         }
211 }
212
213 static krb5_error_code smb_krb5_send_and_recv_func_int(krb5_context context,
214                                                        struct tevent_context *ev,
215                                                        krb5_krbhst_info *hi,
216                                                        struct addrinfo *ai,
217                                                        krb5_send_to_kdc_func func,
218                                                        void *data,
219                                                        time_t timeout,
220                                                        const krb5_data *send_buf,
221                                                        krb5_data *recv_buf)
222 {
223         krb5_error_code ret;
224         NTSTATUS status;
225         const char *name;
226         struct addrinfo *a;
227         struct smb_krb5_socket *smb_krb5;
228
229         DATA_BLOB send_blob;
230
231         TALLOC_CTX *frame = talloc_stackframe();
232         if (frame == NULL) {
233                 return ENOMEM;
234         }
235
236         send_blob = data_blob_const(send_buf->data, send_buf->length);
237
238         for (a = ai; a; a = a->ai_next) {
239                 struct socket_address *remote_addr;
240                 smb_krb5 = talloc(frame, struct smb_krb5_socket);
241                 if (!smb_krb5) {
242                         TALLOC_FREE(frame);
243                         return ENOMEM;
244                 }
245                 smb_krb5->hi = hi;
246
247                 switch (a->ai_family) {
248                 case PF_INET:
249                         name = "ipv4";
250                         break;
251 #ifdef HAVE_IPV6
252                 case PF_INET6:
253                         name = "ipv6";
254                         break;
255 #endif
256                 default:
257                         TALLOC_FREE(frame);
258                         return EINVAL;
259                 }
260
261                 status = NT_STATUS_INVALID_PARAMETER;
262                 switch (hi->proto) {
263                 case KRB5_KRBHST_UDP:
264                         status = socket_create(smb_krb5, name,
265                                                SOCKET_TYPE_DGRAM,
266                                                &smb_krb5->sock, 0);
267                         break;
268                 case KRB5_KRBHST_TCP:
269                         status = socket_create(smb_krb5, name,
270                                                SOCKET_TYPE_STREAM,
271                                                &smb_krb5->sock, 0);
272                         break;
273                 case KRB5_KRBHST_HTTP:
274                         TALLOC_FREE(frame);
275                         return EINVAL;
276                 }
277                 if (!NT_STATUS_IS_OK(status)) {
278                         talloc_free(smb_krb5);
279                         continue;
280                 }
281
282                 remote_addr = socket_address_from_sockaddr(smb_krb5, a->ai_addr, a->ai_addrlen);
283                 if (!remote_addr) {
284                         talloc_free(smb_krb5);
285                         continue;
286                 }
287
288                 status = socket_connect_ev(smb_krb5->sock, NULL, remote_addr, 0, ev);
289                 if (!NT_STATUS_IS_OK(status)) {
290                         talloc_free(smb_krb5);
291                         continue;
292                 }
293
294                 /* Setup the FDE, start listening for read events
295                  * from the start (otherwise we may miss a socket
296                  * drop) and mark as AUTOCLOSE along with the fde */
297
298                 /* Ths is equivilant to EVENT_FD_READABLE(smb_krb5->fde) */
299                 smb_krb5->fde = tevent_add_fd(ev, smb_krb5->sock,
300                                               socket_get_fd(smb_krb5->sock),
301                                               TEVENT_FD_READ,
302                                               smb_krb5_socket_handler, smb_krb5);
303                 /* its now the job of the event layer to close the socket */
304                 tevent_fd_set_close_fn(smb_krb5->fde, socket_tevent_fd_close_fn);
305                 socket_set_flags(smb_krb5->sock, SOCKET_FLAG_NOCLOSE);
306
307                 tevent_add_timer(ev, smb_krb5,
308                                  timeval_current_ofs(timeout, 0),
309                                  smb_krb5_request_timeout, smb_krb5);
310
311                 smb_krb5->status = NT_STATUS_OK;
312                 smb_krb5->reply = data_blob(NULL, 0);
313
314                 switch (hi->proto) {
315                 case KRB5_KRBHST_UDP:
316                         TEVENT_FD_WRITEABLE(smb_krb5->fde);
317                         smb_krb5->request = send_blob;
318                         break;
319                 case KRB5_KRBHST_TCP:
320
321                         smb_krb5->packet = packet_init(smb_krb5);
322                         if (smb_krb5->packet == NULL) {
323                                 talloc_free(smb_krb5);
324                                 return ENOMEM;
325                         }
326                         packet_set_private(smb_krb5->packet, smb_krb5);
327                         packet_set_socket(smb_krb5->packet, smb_krb5->sock);
328                         packet_set_callback(smb_krb5->packet, smb_krb5_full_packet);
329                         packet_set_full_request(smb_krb5->packet, packet_full_request_u32);
330                         packet_set_error_handler(smb_krb5->packet, smb_krb5_error_handler);
331                         packet_set_event_context(smb_krb5->packet, ev);
332                         packet_set_fde(smb_krb5->packet, smb_krb5->fde);
333
334                         smb_krb5->request = data_blob_talloc(smb_krb5, NULL, send_blob.length + 4);
335                         RSIVAL(smb_krb5->request.data, 0, send_blob.length);
336                         memcpy(smb_krb5->request.data+4, send_blob.data, send_blob.length);
337                         packet_send(smb_krb5->packet, smb_krb5->request);
338                         break;
339                 case KRB5_KRBHST_HTTP:
340                         TALLOC_FREE(frame);
341                         return EINVAL;
342                 }
343                 while ((NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
344                         if (tevent_loop_once(ev) != 0) {
345                                 TALLOC_FREE(frame);
346                                 return EINVAL;
347                         }
348
349                         if (func) {
350                                 /* After each and every event loop, reset the
351                                  * send_to_kdc pointers to what they were when
352                                  * we entered this loop.  That way, if a
353                                  * nested event has invalidated them, we put
354                                  * it back before we return to the heimdal
355                                  * code */
356                                 ret = krb5_set_send_to_kdc_func(context,
357                                                                 func,
358                                                                 data);
359                                 if (ret != 0) {
360                                         TALLOC_FREE(frame);
361                                         return ret;
362                                 }
363                         }
364                 }
365                 if (NT_STATUS_EQUAL(smb_krb5->status, NT_STATUS_IO_TIMEOUT)) {
366                         talloc_free(smb_krb5);
367                         continue;
368                 }
369
370                 if (!NT_STATUS_IS_OK(smb_krb5->status)) {
371                         struct tsocket_address *addr = socket_address_to_tsocket_address(smb_krb5, remote_addr);
372                         const char *addr_string = NULL;
373                         if (addr) {
374                                 addr_string = tsocket_address_inet_addr_string(addr, smb_krb5);
375                         } else {
376                                 addr_string = NULL;
377                         }
378                         DEBUG(2,("Error reading smb_krb5 reply packet: %s from %s\n", nt_errstr(smb_krb5->status),
379                                  addr_string));
380                         talloc_free(smb_krb5);
381                         continue;
382                 }
383
384                 ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
385                 if (ret) {
386                         TALLOC_FREE(frame);
387                         return ret;
388                 }
389                 talloc_free(smb_krb5);
390
391                 break;
392         }
393         TALLOC_FREE(frame);
394         if (a) {
395                 return 0;
396         }
397         return KRB5_KDC_UNREACH;
398 }
399
400 krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
401                                             void *data,
402                                             krb5_krbhst_info *hi,
403                                             time_t timeout,
404                                             const krb5_data *send_buf,
405                                             krb5_data *recv_buf)
406 {
407         krb5_error_code ret;
408         struct addrinfo *ai;
409
410         struct tevent_context *ev;
411         TALLOC_CTX *frame = talloc_stackframe();
412         if (frame == NULL) {
413                 return ENOMEM;
414         }
415
416         if (data == NULL) {
417                 /* If no event context was available, then create one for this loop */
418                 ev = samba_tevent_context_init(frame);
419                 if (ev == NULL) {
420                         TALLOC_FREE(frame);
421                         return ENOMEM;
422                 }
423         } else {
424                 ev = talloc_get_type_abort(data, struct tevent_context);
425         }
426
427         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
428         if (ret) {
429                 TALLOC_FREE(frame);
430                 return ret;
431         }
432
433         ret = smb_krb5_send_and_recv_func_int(context, ev, hi, ai, smb_krb5_send_and_recv_func, data, timeout, send_buf, recv_buf);
434         TALLOC_FREE(frame);
435         return ret;
436 }
437
438 krb5_error_code smb_krb5_send_and_recv_func_forced(krb5_context context,
439                                                    void *data, /* struct addrinfo */
440                                                    krb5_krbhst_info *hi,
441                                                    time_t timeout,
442                                                    const krb5_data *send_buf,
443                                                    krb5_data *recv_buf)
444 {
445         krb5_error_code k5ret;
446         struct addrinfo *ai = data;
447
448         struct tevent_context *ev;
449         TALLOC_CTX *frame = talloc_stackframe();
450         if (frame == NULL) {
451                 return ENOMEM;
452         }
453
454         /* no event context is passed in, create one for this loop */
455         ev = samba_tevent_context_init(frame);
456         if (ev == NULL) {
457                 TALLOC_FREE(frame);
458                 return ENOMEM;
459         }
460
461         /* No need to pass in send_and_recv functions, we won't nest on this private event loop */
462         k5ret = smb_krb5_send_and_recv_func_int(context, ev, hi, ai, NULL, NULL,
463                                                 timeout, send_buf, recv_buf);
464         TALLOC_FREE(frame);
465         return k5ret;
466 }
467 #endif
468
469 krb5_error_code
470 smb_krb5_init_context_basic(TALLOC_CTX *tmp_ctx,
471                             struct loadparm_context *lp_ctx,
472                             krb5_context *_krb5_context)
473 {
474         krb5_error_code ret;
475 #ifdef SAMBA4_USES_HEIMDAL
476         char **config_files;
477         const char *config_file, *realm;
478 #endif
479         krb5_context krb5_ctx;
480
481         initialize_krb5_error_table();
482
483         ret = krb5_init_context(&krb5_ctx);
484         if (ret) {
485                 DEBUG(1,("krb5_init_context failed (%s)\n",
486                          error_message(ret)));
487                 return ret;
488         }
489
490         /* The MIT Kerberos build relies on using the system krb5.conf file.
491          * If you really want to use another file please set KRB5_CONFIG
492          * accordingly. */
493 #ifdef SAMBA4_USES_HEIMDAL
494         config_file = lpcfg_config_path(tmp_ctx, lp_ctx, "krb5.conf");
495         if (!config_file) {
496                 krb5_free_context(krb5_ctx);
497                 return ENOMEM;
498         }
499
500         /* Use our local krb5.conf file by default */
501         ret = krb5_prepend_config_files_default(config_file, &config_files);
502         if (ret) {
503                 DEBUG(1,("krb5_prepend_config_files_default failed (%s)\n",
504                          smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
505                 krb5_free_context(krb5_ctx);
506                 return ret;
507         }
508
509         ret = krb5_set_config_files(krb5_ctx, config_files);
510         krb5_free_config_files(config_files);
511         if (ret) {
512                 DEBUG(1,("krb5_set_config_files failed (%s)\n",
513                          smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
514                 krb5_free_context(krb5_ctx);
515                 return ret;
516         }
517
518         realm = lpcfg_realm(lp_ctx);
519         if (realm != NULL) {
520                 ret = krb5_set_default_realm(krb5_ctx, realm);
521                 if (ret) {
522                         DEBUG(1,("krb5_set_default_realm failed (%s)\n",
523                                  smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
524                         krb5_free_context(krb5_ctx);
525                         return ret;
526                 }
527         }
528 #endif
529         *_krb5_context = krb5_ctx;
530         return 0;
531 }
532
533 krb5_error_code smb_krb5_init_context(void *parent_ctx,
534                                       struct loadparm_context *lp_ctx,
535                                       struct smb_krb5_context **smb_krb5_context)
536 {
537         krb5_error_code ret;
538         TALLOC_CTX *tmp_ctx;
539         krb5_context kctx;
540 #ifdef SAMBA4_USES_HEIMDAL
541         krb5_log_facility *logf;
542 #endif
543
544         initialize_krb5_error_table();
545
546         tmp_ctx = talloc_new(parent_ctx);
547         *smb_krb5_context = talloc_zero(tmp_ctx, struct smb_krb5_context);
548
549         if (!*smb_krb5_context || !tmp_ctx) {
550                 talloc_free(tmp_ctx);
551                 return ENOMEM;
552         }
553
554         ret = smb_krb5_init_context_basic(tmp_ctx, lp_ctx, &kctx);
555         if (ret) {
556                 DEBUG(1,("smb_krb5_context_init_basic failed (%s)\n",
557                          error_message(ret)));
558                 talloc_free(tmp_ctx);
559                 return ret;
560         }
561         (*smb_krb5_context)->krb5_context = kctx;
562
563         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy);
564
565 #ifdef SAMBA4_USES_HEIMDAL
566         /* TODO: Should we have a different name here? */
567         ret = krb5_initlog(kctx, "Samba", &logf);
568
569         if (ret) {
570                 DEBUG(1,("krb5_initlog failed (%s)\n",
571                          smb_get_krb5_error_message(kctx, ret, tmp_ctx)));
572                 talloc_free(tmp_ctx);
573                 return ret;
574         }
575         (*smb_krb5_context)->pvt_log_data = logf;
576
577         ret = krb5_addlog_func(kctx, logf, 0 /* min */, -1 /* max */,
578                                smb_krb5_debug_wrapper,
579                                 smb_krb5_debug_close, NULL);
580         if (ret) {
581                 DEBUG(1,("krb5_addlog_func failed (%s)\n",
582                          smb_get_krb5_error_message(kctx, ret, tmp_ctx)));
583                 talloc_free(tmp_ctx);
584                 return ret;
585         }
586         krb5_set_warn_dest(kctx, logf);
587
588         /* Set options in kerberos */
589
590         krb5_set_dns_canonicalize_hostname(kctx,
591                         lpcfg_parm_bool(lp_ctx, NULL, "krb5",
592                                         "set_dns_canonicalize", false));
593 #endif
594         talloc_steal(parent_ctx, *smb_krb5_context);
595         talloc_free(tmp_ctx);
596
597         return 0;
598 }
599
600 #ifdef SAMBA4_USES_HEIMDAL
601 krb5_error_code smb_krb5_context_set_event_ctx(struct smb_krb5_context *smb_krb5_context,
602                                                struct tevent_context *ev,
603                                                struct tevent_context **previous_ev)
604 {
605         int ret;
606         if (!ev) {
607                 return EINVAL;
608         }
609
610         *previous_ev = smb_krb5_context->current_ev;
611
612         smb_krb5_context->current_ev = talloc_reference(smb_krb5_context, ev);
613         if (!smb_krb5_context->current_ev) {
614                 return ENOMEM;
615         }
616
617         /* Set use of our socket lib */
618         ret = krb5_set_send_to_kdc_func(smb_krb5_context->krb5_context,
619                                         smb_krb5_send_and_recv_func,
620                                         ev);
621         if (ret) {
622                 TALLOC_CTX *tmp_ctx = talloc_new(NULL);
623                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
624                          smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, tmp_ctx)));
625                 talloc_free(tmp_ctx);
626                 talloc_unlink(smb_krb5_context, smb_krb5_context->current_ev);
627                 smb_krb5_context->current_ev = NULL;
628                 return ret;
629         }
630         return 0;
631 }
632
633 krb5_error_code smb_krb5_context_remove_event_ctx(struct smb_krb5_context *smb_krb5_context,
634                                                   struct tevent_context *previous_ev,
635                                                   struct tevent_context *ev)
636 {
637         int ret;
638         talloc_unlink(smb_krb5_context, ev);
639         /* If there was a mismatch with things happening on a stack, then don't wipe things */
640         smb_krb5_context->current_ev = previous_ev;
641         /* Set use of our socket lib */
642         ret = krb5_set_send_to_kdc_func(smb_krb5_context->krb5_context,
643                                         smb_krb5_send_and_recv_func,
644                                         previous_ev);
645         if (ret) {
646                 TALLOC_CTX *tmp_ctx = talloc_new(NULL);
647                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
648                          smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, tmp_ctx)));
649                 talloc_free(tmp_ctx);
650                 return ret;
651         }
652         return 0;
653 }
654 #endif