r26449: Support configuration without a known configuration dir.
[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 "heimdal/lib/krb5/krb5_locl.h"
26 #include "auth/kerberos/kerberos.h"
27 #include "lib/socket/socket.h"
28 #include "lib/stream/packet.h"
29 #include "system/network.h"
30 #include "lib/events/events.h"
31 #include "roken.h"
32 #include "param/param.h"
33 #include "libcli/resolve/resolve.h"
34
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 fd_event *fde;
43
44         NTSTATUS status;
45         DATA_BLOB request, reply;
46         
47         struct packet_context *packet;
48
49         size_t partial_read;
50
51         krb5_krbhst_info *hi;
52 };
53
54 static int smb_krb5_context_destroy_1(struct smb_krb5_context *ctx)
55 {
56         krb5_free_context(ctx->krb5_context); 
57         return 0;
58 }
59
60 static int smb_krb5_context_destroy_2(struct smb_krb5_context *ctx)
61 {
62         /* Otherwise krb5_free_context will try and close what we have already free()ed */
63         krb5_set_warn_dest(ctx->krb5_context, NULL);
64         krb5_closelog(ctx->krb5_context, ctx->logf);
65         smb_krb5_context_destroy_1(ctx);
66         return 0;
67 }
68
69 /* We never close down the DEBUG system, and no need to unreference the use */
70 static void smb_krb5_debug_close(void *private) {
71         return;
72 }
73
74 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private) 
75 {
76         DEBUG(2, ("Kerberos: %s\n", msg));
77 }
78
79 /*
80   handle recv events on a smb_krb5 socket
81 */
82 static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
83 {
84         TALLOC_CTX *tmp_ctx = talloc_new(smb_krb5);
85         DATA_BLOB blob;
86         size_t nread, dsize;
87
88         smb_krb5->status = socket_pending(smb_krb5->sock, &dsize);
89         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
90                 talloc_free(tmp_ctx);
91                 return;
92         }
93         
94         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
95         if (blob.data == NULL && dsize != 0) {
96                 smb_krb5->status = NT_STATUS_NO_MEMORY;
97                 talloc_free(tmp_ctx);
98                 return;
99         }
100         
101         smb_krb5->status = socket_recv(smb_krb5->sock, blob.data, blob.length, &nread);
102         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
103                 talloc_free(tmp_ctx);
104                 return;
105         }
106         blob.length = nread;
107         
108         if (nread == 0) {
109                 smb_krb5->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
110                 talloc_free(tmp_ctx);
111                 return;
112         }
113         
114         DEBUG(2,("Received smb_krb5 packet of length %d\n", 
115                  (int)blob.length));
116         
117         talloc_steal(smb_krb5, blob.data);
118         smb_krb5->reply = blob;
119         talloc_free(tmp_ctx);
120 }
121
122 static NTSTATUS smb_krb5_full_packet(void *private, DATA_BLOB data) 
123 {
124         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
125         talloc_steal(smb_krb5, data.data);
126         smb_krb5->reply = data;
127         smb_krb5->reply.length -= 4;
128         smb_krb5->reply.data += 4;
129         return NT_STATUS_OK;
130 }
131
132 /*
133   handle request timeouts
134 */
135 static void smb_krb5_request_timeout(struct event_context *event_ctx, 
136                                   struct timed_event *te, struct timeval t,
137                                   void *private)
138 {
139         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
140         DEBUG(5,("Timed out smb_krb5 packet\n"));
141         smb_krb5->status = NT_STATUS_IO_TIMEOUT;
142 }
143
144 static void smb_krb5_error_handler(void *private, NTSTATUS status) 
145 {
146         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
147         smb_krb5->status = status;
148 }
149
150 /*
151   handle send events on a smb_krb5 socket
152 */
153 static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
154 {
155         NTSTATUS status;
156
157         size_t len;
158         
159         len = smb_krb5->request.length;
160         status = socket_send(smb_krb5->sock, &smb_krb5->request, &len);
161
162         if (!NT_STATUS_IS_OK(status)) return;
163         
164         EVENT_FD_READABLE(smb_krb5->fde);
165
166         EVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
167         return;
168 }
169
170
171 /*
172   handle fd events on a smb_krb5_socket
173 */
174 static void smb_krb5_socket_handler(struct event_context *ev, struct fd_event *fde,
175                                  uint16_t flags, void *private)
176 {
177         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
178         switch (smb_krb5->hi->proto) {
179         case KRB5_KRBHST_UDP:
180                 if (flags & EVENT_FD_READ) {
181                         smb_krb5_socket_recv(smb_krb5);
182                         return;
183                 }
184                 if (flags & EVENT_FD_WRITE) {
185                         smb_krb5_socket_send(smb_krb5);
186                         return;
187                 }
188                 /* not reached */
189                 return;
190         case KRB5_KRBHST_TCP:
191                 if (flags & EVENT_FD_READ) {
192                         packet_recv(smb_krb5->packet);
193                         return;
194                 }
195                 if (flags & EVENT_FD_WRITE) {
196                         packet_queue_run(smb_krb5->packet);
197                         return;
198                 }
199                 /* not reached */
200                 return;
201         case KRB5_KRBHST_HTTP:
202                 /* can't happen */
203                 break;
204         }
205 }
206
207
208 krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
209                                             void *data,
210                                             krb5_krbhst_info *hi,
211                                             const krb5_data *send_buf,
212                                             krb5_data *recv_buf)
213 {
214         krb5_error_code ret;
215         NTSTATUS status;
216         struct socket_address *remote_addr;
217         const char *name;
218         struct addrinfo *ai, *a;
219         struct smb_krb5_socket *smb_krb5;
220
221         struct event_context *ev = talloc_get_type(data, struct event_context);
222
223         DATA_BLOB send_blob = data_blob_const(send_buf->data, send_buf->length);
224
225         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
226         if (ret) {
227                 return ret;
228         }
229
230         for (a = ai; a; a = ai->ai_next) {
231                 smb_krb5 = talloc(NULL, struct smb_krb5_socket);
232                 if (!smb_krb5) {
233                         return ENOMEM;
234                 }
235                 smb_krb5->hi = hi;
236                 
237                 switch (a->ai_family) {
238                 case PF_INET:
239                         name = "ipv4";
240                         break;
241 #ifdef HAVE_IPV6
242                 case PF_INET6:
243                         name = "ipv6";
244                         break;
245 #endif
246                 default:
247                         talloc_free(smb_krb5);
248                         return EINVAL;
249                 }
250                 
251                 status = NT_STATUS_INVALID_PARAMETER;
252                 switch (hi->proto) {
253                 case KRB5_KRBHST_UDP:
254                         if (lp_parm_bool(global_loadparm, NULL, "krb5", "udp", true)) {
255                                 status = socket_create(name, SOCKET_TYPE_DGRAM, &smb_krb5->sock, 0);
256                         }
257                         break;
258                 case KRB5_KRBHST_TCP:
259                         if (lp_parm_bool(global_loadparm, NULL, "krb5", "tcp", true)) {
260                                 status = socket_create(name, SOCKET_TYPE_STREAM, &smb_krb5->sock, 0);
261                         }
262                         break;
263                 case KRB5_KRBHST_HTTP:
264                         talloc_free(smb_krb5);
265                         return EINVAL;
266                 }
267                 if (!NT_STATUS_IS_OK(status)) {
268                         talloc_free(smb_krb5);
269                         continue;
270                 }
271
272                 talloc_steal(smb_krb5, smb_krb5->sock);
273                 
274                 remote_addr = socket_address_from_sockaddr(smb_krb5, a->ai_addr, a->ai_addrlen); 
275                 if (!remote_addr) {
276                         talloc_free(smb_krb5);
277                         continue;
278                 }
279
280                 status = socket_connect_ev(smb_krb5->sock, NULL, remote_addr, 0, 
281                                            NULL, ev); 
282                 if (!NT_STATUS_IS_OK(status)) {
283                         talloc_free(smb_krb5);
284                         continue;
285                 }
286                 talloc_free(remote_addr);
287
288                 /* Setup the FDE, start listening for read events
289                  * from the start (otherwise we may miss a socket
290                  * drop) and mark as AUTOCLOSE along with the fde */
291
292                 /* Ths is equivilant to EVENT_FD_READABLE(smb_krb5->fde) */
293                 smb_krb5->fde = event_add_fd(ev, smb_krb5->sock, 
294                                              socket_get_fd(smb_krb5->sock), 
295                                              EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
296                                              smb_krb5_socket_handler, smb_krb5);
297                 /* its now the job of the event layer to close the socket */
298                 socket_set_flags(smb_krb5->sock, SOCKET_FLAG_NOCLOSE);
299
300                 event_add_timed(ev, smb_krb5, 
301                                 timeval_current_ofs(context->kdc_timeout, 0),
302                                 smb_krb5_request_timeout, smb_krb5);
303
304                 
305                 smb_krb5->status = NT_STATUS_OK;
306                 smb_krb5->reply = data_blob(NULL, 0);
307
308                 switch (hi->proto) {
309                 case KRB5_KRBHST_UDP:
310                         EVENT_FD_WRITEABLE(smb_krb5->fde);
311                         smb_krb5->request = send_blob;
312                         break;
313                 case KRB5_KRBHST_TCP:
314
315                         smb_krb5->packet = packet_init(smb_krb5);
316                         if (smb_krb5->packet == NULL) {
317                                 talloc_free(smb_krb5);
318                                 return ENOMEM;
319                         }
320                         packet_set_private(smb_krb5->packet, smb_krb5);
321                         packet_set_socket(smb_krb5->packet, smb_krb5->sock);
322                         packet_set_callback(smb_krb5->packet, smb_krb5_full_packet);
323                         packet_set_full_request(smb_krb5->packet, packet_full_request_u32);
324                         packet_set_error_handler(smb_krb5->packet, smb_krb5_error_handler);
325                         packet_set_event_context(smb_krb5->packet, ev);
326                         packet_set_fde(smb_krb5->packet, smb_krb5->fde);
327
328                         smb_krb5->request = data_blob_talloc(smb_krb5, NULL, send_blob.length + 4);
329                         RSIVAL(smb_krb5->request.data, 0, send_blob.length);
330                         memcpy(smb_krb5->request.data+4, send_blob.data, send_blob.length);
331                         packet_send(smb_krb5->packet, smb_krb5->request);
332                         break;
333                 case KRB5_KRBHST_HTTP:
334                         talloc_free(smb_krb5);
335                         return EINVAL;
336                 }
337                 while ((NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
338                         if (event_loop_once(ev) != 0) {
339                                 talloc_free(smb_krb5);
340                                 return EINVAL;
341                         }
342                 }
343                 if (NT_STATUS_EQUAL(smb_krb5->status, NT_STATUS_IO_TIMEOUT)) {
344                         talloc_free(smb_krb5);
345                         continue;
346                 }
347
348                 if (!NT_STATUS_IS_OK(smb_krb5->status)) {
349                         DEBUG(2,("Error reading smb_krb5 reply packet: %s\n", nt_errstr(smb_krb5->status)));
350                         talloc_free(smb_krb5);
351                         continue;
352                 }
353
354                 ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
355                 if (ret) {
356                         talloc_free(smb_krb5);
357                         return ret;
358                 }
359                 talloc_free(smb_krb5);
360                 
361                 break;
362         }
363         if (a) {
364                 return 0;
365         }
366         return KRB5_KDC_UNREACH;
367 }
368
369 krb5_error_code smb_krb5_init_context(void *parent_ctx, 
370                                       struct event_context *ev,
371                                       struct loadparm_context *lp_ctx,
372                                        struct smb_krb5_context **smb_krb5_context) 
373 {
374         krb5_error_code ret;
375         TALLOC_CTX *tmp_ctx;
376         char **config_files;
377         const char *config_file;
378         
379         initialize_krb5_error_table();
380         
381         tmp_ctx = talloc_new(parent_ctx);
382         *smb_krb5_context = talloc(tmp_ctx, struct smb_krb5_context);
383
384         if (!*smb_krb5_context || !tmp_ctx) {
385                 talloc_free(tmp_ctx);
386                 return ENOMEM;
387         }
388
389         ret = krb5_init_context(&(*smb_krb5_context)->krb5_context);
390         if (ret) {
391                 DEBUG(1,("krb5_init_context failed (%s)\n", 
392                          error_message(ret)));
393                 talloc_free(tmp_ctx);
394                 return ret;
395         }
396
397         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_1);
398
399         config_file = config_path(tmp_ctx, lp_ctx, "krb5.conf");
400         if (!config_file) {
401                 talloc_free(tmp_ctx);
402                 return ENOMEM;
403         }
404                 
405         /* Use our local krb5.conf file by default */
406         ret = krb5_prepend_config_files_default(config_file == NULL?"":config_file, &config_files);
407         if (ret) {
408                 DEBUG(1,("krb5_prepend_config_files_default failed (%s)\n", 
409                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
410                 talloc_free(tmp_ctx);
411                 return ret;
412         }
413
414         ret = krb5_set_config_files((*smb_krb5_context)->krb5_context, 
415                                     config_files);
416         krb5_free_config_files(config_files);
417         if (ret) {
418                 DEBUG(1,("krb5_set_config_files failed (%s)\n", 
419                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
420                 talloc_free(tmp_ctx);
421                 return ret;
422         }
423                                                 
424         if (lp_realm(lp_ctx) && *lp_realm(lp_ctx)) {
425                 char *upper_realm = strupper_talloc(tmp_ctx, lp_realm(lp_ctx));
426                 if (!upper_realm) {
427                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm(lp_ctx)));
428                         talloc_free(tmp_ctx);
429                         return ENOMEM;
430                 }
431                 ret = krb5_set_default_realm((*smb_krb5_context)->krb5_context, upper_realm);
432                 if (ret) {
433                         DEBUG(1,("krb5_set_default_realm failed (%s)\n", 
434                                  smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
435                         talloc_free(tmp_ctx);
436                         return ret;
437                 }
438         }
439
440         /* TODO: Should we have a different name here? */
441         ret = krb5_initlog((*smb_krb5_context)->krb5_context, "Samba", &(*smb_krb5_context)->logf);
442         
443         if (ret) {
444                 DEBUG(1,("krb5_initlog failed (%s)\n", 
445                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
446                 talloc_free(tmp_ctx);
447                 return ret;
448         }
449
450         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_2);
451
452         ret = krb5_addlog_func((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf, 0 /* min */, -1 /* max */, 
453                                smb_krb5_debug_wrapper, smb_krb5_debug_close, NULL);
454         if (ret) {
455                 DEBUG(1,("krb5_addlog_func failed (%s)\n", 
456                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
457                 talloc_free(tmp_ctx);
458                 return ret;
459         }
460         krb5_set_warn_dest((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf);
461
462         /* Set use of our socket lib */
463         ret = krb5_set_send_to_kdc_func((*smb_krb5_context)->krb5_context, 
464                                         smb_krb5_send_and_recv_func, 
465                                         ev);
466         if (ret) {
467                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n", 
468                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
469                 talloc_free(tmp_ctx);
470                 return ret;
471         }
472
473         talloc_steal(parent_ctx, *smb_krb5_context);
474         talloc_free(tmp_ctx);
475
476         /* Set options in kerberos */
477
478         krb5_set_dns_canonicalize_hostname((*smb_krb5_context)->krb5_context,
479                                            lp_parm_bool(lp_ctx, NULL, "krb5", "set_dns_canonicalize", false));
480
481         return 0;
482 }
483