s4:lib/tevent: rename structs
[gd/samba-autobuild/.git] / source4 / lib / tls / tls.c
1 /* 
2    Unix SMB/CIFS implementation.
3
4    transport layer security handling code
5
6    Copyright (C) Andrew Tridgell 2004-2005
7    Copyright (C) Stefan Metzmacher 2004
8    Copyright (C) Andrew Bartlett 2006
9  
10    This program is free software; you can redistribute it and/or modify
11    it under the terms of the GNU General Public License as published by
12    the Free Software Foundation; either version 3 of the License, or
13    (at your option) any later version.
14    
15    This program is distributed in the hope that it will be useful,
16    but WITHOUT ANY WARRANTY; without even the implied warranty of
17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18    GNU General Public License for more details.
19    
20    You should have received a copy of the GNU General Public License
21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
22 */
23
24 #include "includes.h"
25 #include "lib/events/events.h"
26 #include "lib/socket/socket.h"
27 #include "lib/tls/tls.h"
28 #include "param/param.h"
29
30 #if ENABLE_GNUTLS
31 #include "gnutls/gnutls.h"
32
33 #define DH_BITS 1024
34
35 #if defined(HAVE_GNUTLS_DATUM) && !defined(HAVE_GNUTLS_DATUM_T)
36 typedef gnutls_datum gnutls_datum_t;
37 #endif
38
39 /* hold persistent tls data */
40 struct tls_params {
41         gnutls_certificate_credentials x509_cred;
42         gnutls_dh_params dh_params;
43         bool tls_enabled;
44 };
45 #endif
46
47 /* hold per connection tls data */
48 struct tls_context {
49         struct socket_context *socket;
50         struct tevent_fd *fde;
51         bool tls_enabled;
52 #if ENABLE_GNUTLS
53         gnutls_session session;
54         bool done_handshake;
55         bool have_first_byte;
56         uint8_t first_byte;
57         bool tls_detect;
58         const char *plain_chars;
59         bool output_pending;
60         gnutls_certificate_credentials xcred;
61         bool interrupted;
62 #endif
63 };
64
65 bool tls_enabled(struct socket_context *sock)
66 {
67         struct tls_context *tls;
68         if (!sock) {
69                 return false;
70         }
71         if (strcmp(sock->backend_name, "tls") != 0) {
72                 return false;
73         }
74         tls = talloc_get_type(sock->private_data, struct tls_context);
75         if (!tls) {
76                 return false;
77         }
78         return tls->tls_enabled;
79 }
80
81
82 #if ENABLE_GNUTLS
83
84 static const struct socket_ops tls_socket_ops;
85
86 static NTSTATUS tls_socket_init(struct socket_context *sock)
87 {
88         switch (sock->type) {
89         case SOCKET_TYPE_STREAM:
90                 break;
91         default:
92                 return NT_STATUS_INVALID_PARAMETER;
93         }
94
95         sock->backend_name = "tls";
96
97         return NT_STATUS_OK;
98 }
99
100 #define TLSCHECK(call) do { \
101         ret = call; \
102         if (ret < 0) { \
103                 DEBUG(0,("TLS %s - %s\n", #call, gnutls_strerror(ret))); \
104                 goto failed; \
105         } \
106 } while (0)
107
108
109 /*
110   callback for reading from a socket
111 */
112 static ssize_t tls_pull(gnutls_transport_ptr ptr, void *buf, size_t size)
113 {
114         struct tls_context *tls = talloc_get_type(ptr, struct tls_context);
115         NTSTATUS status;
116         size_t nread;
117         
118         if (tls->have_first_byte) {
119                 *(uint8_t *)buf = tls->first_byte;
120                 tls->have_first_byte = false;
121                 return 1;
122         }
123
124         status = socket_recv(tls->socket, buf, size, &nread);
125         if (NT_STATUS_EQUAL(status, NT_STATUS_END_OF_FILE)) {
126                 return 0;
127         }
128         if (NT_STATUS_IS_ERR(status)) {
129                 EVENT_FD_NOT_READABLE(tls->fde);
130                 EVENT_FD_NOT_WRITEABLE(tls->fde);
131                 errno = EBADF;
132                 return -1;
133         }
134         if (!NT_STATUS_IS_OK(status)) {
135                 EVENT_FD_READABLE(tls->fde);
136                 errno = EAGAIN;
137                 return -1;
138         }
139         if (tls->output_pending) {
140                 EVENT_FD_WRITEABLE(tls->fde);
141         }
142         if (size != nread) {
143                 EVENT_FD_READABLE(tls->fde);
144         }
145         return nread;
146 }
147
148 /*
149   callback for writing to a socket
150 */
151 static ssize_t tls_push(gnutls_transport_ptr ptr, const void *buf, size_t size)
152 {
153         struct tls_context *tls = talloc_get_type(ptr, struct tls_context);
154         NTSTATUS status;
155         size_t nwritten;
156         DATA_BLOB b;
157
158         if (!tls->tls_enabled) {
159                 return size;
160         }
161
162         b.data = discard_const(buf);
163         b.length = size;
164
165         status = socket_send(tls->socket, &b, &nwritten);
166         if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
167                 errno = EAGAIN;
168                 return -1;
169         }
170         if (!NT_STATUS_IS_OK(status)) {
171                 EVENT_FD_WRITEABLE(tls->fde);
172                 return -1;
173         }
174         if (size != nwritten) {
175                 EVENT_FD_WRITEABLE(tls->fde);
176         }
177         return nwritten;
178 }
179
180 /*
181   destroy a tls session
182  */
183 static int tls_destructor(struct tls_context *tls)
184 {
185         int ret;
186         ret = gnutls_bye(tls->session, GNUTLS_SHUT_WR);
187         if (ret < 0) {
188                 DEBUG(0,("TLS gnutls_bye failed - %s\n", gnutls_strerror(ret)));
189         }
190         return 0;
191 }
192
193
194 /*
195   possibly continue the handshake process
196 */
197 static NTSTATUS tls_handshake(struct tls_context *tls)
198 {
199         int ret;
200
201         if (tls->done_handshake) {
202                 return NT_STATUS_OK;
203         }
204         
205         ret = gnutls_handshake(tls->session);
206         if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
207                 if (gnutls_record_get_direction(tls->session) == 1) {
208                         EVENT_FD_WRITEABLE(tls->fde);
209                 }
210                 return STATUS_MORE_ENTRIES;
211         }
212         if (ret < 0) {
213                 DEBUG(0,("TLS gnutls_handshake failed - %s\n", gnutls_strerror(ret)));
214                 return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
215         }
216         tls->done_handshake = true;
217         return NT_STATUS_OK;
218 }
219
220 /*
221   possibly continue an interrupted operation
222 */
223 static NTSTATUS tls_interrupted(struct tls_context *tls)
224 {
225         int ret;
226
227         if (!tls->interrupted) {
228                 return NT_STATUS_OK;
229         }
230         if (gnutls_record_get_direction(tls->session) == 1) {
231                 ret = gnutls_record_send(tls->session, NULL, 0);
232         } else {
233                 ret = gnutls_record_recv(tls->session, NULL, 0);
234         }
235         if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
236                 return STATUS_MORE_ENTRIES;
237         }
238         tls->interrupted = false;
239         return NT_STATUS_OK;
240 }
241
242 /*
243   see how many bytes are pending on the connection
244 */
245 static NTSTATUS tls_socket_pending(struct socket_context *sock, size_t *npending)
246 {
247         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
248         if (!tls->tls_enabled || tls->tls_detect) {
249                 return socket_pending(tls->socket, npending);
250         }
251         *npending = gnutls_record_check_pending(tls->session);
252         if (*npending == 0) {
253                 NTSTATUS status = socket_pending(tls->socket, npending);
254                 if (*npending == 0) {
255                         /* seems to be a gnutls bug */
256                         (*npending) = 100;
257                 }
258                 return status;
259         }
260         return NT_STATUS_OK;
261 }
262
263 /*
264   receive data either by tls or normal socket_recv
265 */
266 static NTSTATUS tls_socket_recv(struct socket_context *sock, void *buf, 
267                                 size_t wantlen, size_t *nread)
268 {
269         int ret;
270         NTSTATUS status;
271         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
272
273         if (tls->tls_enabled && tls->tls_detect) {
274                 status = socket_recv(tls->socket, &tls->first_byte, 1, nread);
275                 NT_STATUS_NOT_OK_RETURN(status);
276                 if (*nread == 0) return NT_STATUS_OK;
277                 tls->tls_detect = false;
278                 /* look for the first byte of a valid HTTP operation */
279                 if (strchr(tls->plain_chars, tls->first_byte)) {
280                         /* not a tls link */
281                         tls->tls_enabled = false;
282                         *(uint8_t *)buf = tls->first_byte;
283                         return NT_STATUS_OK;
284                 }
285                 tls->have_first_byte = true;
286         }
287
288         if (!tls->tls_enabled) {
289                 return socket_recv(tls->socket, buf, wantlen, nread);
290         }
291
292         status = tls_handshake(tls);
293         NT_STATUS_NOT_OK_RETURN(status);
294
295         status = tls_interrupted(tls);
296         NT_STATUS_NOT_OK_RETURN(status);
297
298         ret = gnutls_record_recv(tls->session, buf, wantlen);
299         if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
300                 if (gnutls_record_get_direction(tls->session) == 1) {
301                         EVENT_FD_WRITEABLE(tls->fde);
302                 }
303                 tls->interrupted = true;
304                 return STATUS_MORE_ENTRIES;
305         }
306         if (ret < 0) {
307                 return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
308         }
309         *nread = ret;
310         return NT_STATUS_OK;
311 }
312
313
314 /*
315   send data either by tls or normal socket_recv
316 */
317 static NTSTATUS tls_socket_send(struct socket_context *sock, 
318                                 const DATA_BLOB *blob, size_t *sendlen)
319 {
320         NTSTATUS status;
321         int ret;
322         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
323
324         if (!tls->tls_enabled) {
325                 return socket_send(tls->socket, blob, sendlen);
326         }
327
328         status = tls_handshake(tls);
329         NT_STATUS_NOT_OK_RETURN(status);
330
331         status = tls_interrupted(tls);
332         NT_STATUS_NOT_OK_RETURN(status);
333
334         ret = gnutls_record_send(tls->session, blob->data, blob->length);
335         if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
336                 if (gnutls_record_get_direction(tls->session) == 1) {
337                         EVENT_FD_WRITEABLE(tls->fde);
338                 }
339                 tls->interrupted = true;
340                 return STATUS_MORE_ENTRIES;
341         }
342         if (ret < 0) {
343                 DEBUG(0,("gnutls_record_send of %d failed - %s\n", (int)blob->length, gnutls_strerror(ret)));
344                 return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
345         }
346         *sendlen = ret;
347         tls->output_pending = (ret < blob->length);
348         return NT_STATUS_OK;
349 }
350
351
352 /*
353   initialise global tls state
354 */
355 struct tls_params *tls_initialise(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx)
356 {
357         struct tls_params *params;
358         int ret;
359         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
360         const char *keyfile = lp_tls_keyfile(tmp_ctx, lp_ctx);
361         const char *certfile = lp_tls_certfile(tmp_ctx, lp_ctx);
362         const char *cafile = lp_tls_cafile(tmp_ctx, lp_ctx);
363         const char *crlfile = lp_tls_crlfile(tmp_ctx, lp_ctx);
364         const char *dhpfile = lp_tls_dhpfile(tmp_ctx, lp_ctx);
365         void tls_cert_generate(TALLOC_CTX *, const char *, const char *, const char *);
366         params = talloc(mem_ctx, struct tls_params);
367         if (params == NULL) {
368                 talloc_free(tmp_ctx);
369                 return NULL;
370         }
371
372         if (!lp_tls_enabled(lp_ctx) || keyfile == NULL || *keyfile == 0) {
373                 params->tls_enabled = false;
374                 talloc_free(tmp_ctx);
375                 return params;
376         }
377
378         if (!file_exist(cafile)) {
379                 tls_cert_generate(params, keyfile, certfile, cafile);
380         }
381
382         ret = gnutls_global_init();
383         if (ret < 0) goto init_failed;
384
385         gnutls_certificate_allocate_credentials(&params->x509_cred);
386         if (ret < 0) goto init_failed;
387
388         if (cafile && *cafile) {
389                 ret = gnutls_certificate_set_x509_trust_file(params->x509_cred, cafile, 
390                                                              GNUTLS_X509_FMT_PEM);      
391                 if (ret < 0) {
392                         DEBUG(0,("TLS failed to initialise cafile %s\n", cafile));
393                         goto init_failed;
394                 }
395         }
396
397         if (crlfile && *crlfile) {
398                 ret = gnutls_certificate_set_x509_crl_file(params->x509_cred, 
399                                                            crlfile, 
400                                                            GNUTLS_X509_FMT_PEM);
401                 if (ret < 0) {
402                         DEBUG(0,("TLS failed to initialise crlfile %s\n", crlfile));
403                         goto init_failed;
404                 }
405         }
406         
407         ret = gnutls_certificate_set_x509_key_file(params->x509_cred, 
408                                                    certfile, keyfile,
409                                                    GNUTLS_X509_FMT_PEM);
410         if (ret < 0) {
411                 DEBUG(0,("TLS failed to initialise certfile %s and keyfile %s\n", 
412                          certfile, keyfile));
413                 goto init_failed;
414         }
415         
416         
417         ret = gnutls_dh_params_init(&params->dh_params);
418         if (ret < 0) goto init_failed;
419
420         if (dhpfile && *dhpfile) {
421                 gnutls_datum_t dhparms;
422                 size_t size;
423                 dhparms.data = (uint8_t *)file_load(dhpfile, &size, 0, mem_ctx);
424
425                 if (!dhparms.data) {
426                         DEBUG(0,("Failed to read DH Parms from %s\n", dhpfile));
427                         goto init_failed;
428                 }
429                 dhparms.size = size;
430                         
431                 ret = gnutls_dh_params_import_pkcs3(params->dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
432                 if (ret < 0) goto init_failed;
433         } else {
434                 ret = gnutls_dh_params_generate2(params->dh_params, DH_BITS);
435                 if (ret < 0) goto init_failed;
436         }
437                 
438         gnutls_certificate_set_dh_params(params->x509_cred, params->dh_params);
439
440         params->tls_enabled = true;
441
442         talloc_free(tmp_ctx);
443         return params;
444
445 init_failed:
446         DEBUG(0,("GNUTLS failed to initialise - %s\n", gnutls_strerror(ret)));
447         params->tls_enabled = false;
448         talloc_free(tmp_ctx);
449         return params;
450 }
451
452
453 /*
454   setup for a new connection
455 */
456 struct socket_context *tls_init_server(struct tls_params *params, 
457                                        struct socket_context *socket_ctx,
458                                        struct tevent_fd *fde, 
459                                        const char *plain_chars)
460 {
461         struct tls_context *tls;
462         int ret;
463         struct socket_context *new_sock;
464         NTSTATUS nt_status;
465         
466         nt_status = socket_create_with_ops(socket_ctx, &tls_socket_ops, &new_sock, 
467                                            SOCKET_TYPE_STREAM, 
468                                            socket_ctx->flags | SOCKET_FLAG_ENCRYPT);
469         if (!NT_STATUS_IS_OK(nt_status)) {
470                 return NULL;
471         }
472
473         tls = talloc(new_sock, struct tls_context);
474         if (tls == NULL) {
475                 return NULL;
476         }
477
478         tls->socket          = socket_ctx;
479         tls->fde             = fde;
480         if (talloc_reference(tls, fde) == NULL) {
481                 talloc_free(new_sock);
482                 return NULL;
483         }
484         if (talloc_reference(tls, socket_ctx) == NULL) {
485                 talloc_free(new_sock);
486                 return NULL;
487         }
488
489         new_sock->private_data    = tls;
490
491         if (!params->tls_enabled) {
492                 talloc_free(new_sock);
493                 return NULL;
494         }
495
496         TLSCHECK(gnutls_init(&tls->session, GNUTLS_SERVER));
497
498         talloc_set_destructor(tls, tls_destructor);
499
500         TLSCHECK(gnutls_set_default_priority(tls->session));
501         TLSCHECK(gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, 
502                                         params->x509_cred));
503         gnutls_certificate_server_set_request(tls->session, GNUTLS_CERT_REQUEST);
504         gnutls_dh_set_prime_bits(tls->session, DH_BITS);
505         gnutls_transport_set_ptr(tls->session, (gnutls_transport_ptr)tls);
506         gnutls_transport_set_pull_function(tls->session, (gnutls_pull_func)tls_pull);
507         gnutls_transport_set_push_function(tls->session, (gnutls_push_func)tls_push);
508         gnutls_transport_set_lowat(tls->session, 0);
509
510         tls->plain_chars = plain_chars;
511         if (plain_chars) {
512                 tls->tls_detect = true;
513         } else {
514                 tls->tls_detect = false;
515         }
516
517         tls->output_pending  = false;
518         tls->done_handshake  = false;
519         tls->have_first_byte = false;
520         tls->tls_enabled     = true;
521         tls->interrupted     = false;
522         
523         new_sock->state = SOCKET_STATE_SERVER_CONNECTED;
524
525         return new_sock;
526
527 failed:
528         DEBUG(0,("TLS init connection failed - %s\n", gnutls_strerror(ret)));
529         talloc_free(new_sock);
530         return NULL;
531 }
532
533
534 /*
535   setup for a new client connection
536 */
537 struct socket_context *tls_init_client(struct socket_context *socket_ctx,
538                                        struct tevent_fd *fde,
539                                        const char *ca_path)
540 {
541         struct tls_context *tls;
542         int ret = 0;
543         const int cert_type_priority[] = { GNUTLS_CRT_X509, GNUTLS_CRT_OPENPGP, 0 };
544         char *cafile;
545         struct socket_context *new_sock;
546         NTSTATUS nt_status;
547         
548         nt_status = socket_create_with_ops(socket_ctx, &tls_socket_ops, &new_sock, 
549                                            SOCKET_TYPE_STREAM, 
550                                            socket_ctx->flags | SOCKET_FLAG_ENCRYPT);
551         if (!NT_STATUS_IS_OK(nt_status)) {
552                 return NULL;
553         }
554
555         tls = talloc(new_sock, struct tls_context);
556         if (tls == NULL) return NULL;
557
558         tls->socket          = socket_ctx;
559         tls->fde             = fde;
560         if (talloc_reference(tls, fde) == NULL) {
561                 return NULL;
562         }
563         if (talloc_reference(tls, socket_ctx) == NULL) {
564                 return NULL;
565         }
566         new_sock->private_data    = tls;
567
568         gnutls_global_init();
569
570         gnutls_certificate_allocate_credentials(&tls->xcred);
571         gnutls_certificate_set_x509_trust_file(tls->xcred, cafile, GNUTLS_X509_FMT_PEM);
572         TLSCHECK(gnutls_init(&tls->session, GNUTLS_CLIENT));
573         TLSCHECK(gnutls_set_default_priority(tls->session));
574         gnutls_certificate_type_set_priority(tls->session, cert_type_priority);
575         TLSCHECK(gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, tls->xcred));
576
577         talloc_set_destructor(tls, tls_destructor);
578
579         gnutls_transport_set_ptr(tls->session, (gnutls_transport_ptr)tls);
580         gnutls_transport_set_pull_function(tls->session, (gnutls_pull_func)tls_pull);
581         gnutls_transport_set_push_function(tls->session, (gnutls_push_func)tls_push);
582         gnutls_transport_set_lowat(tls->session, 0);
583         tls->tls_detect = false;
584
585         tls->output_pending  = false;
586         tls->done_handshake  = false;
587         tls->have_first_byte = false;
588         tls->tls_enabled     = true;
589         tls->interrupted     = false;
590         
591         new_sock->state = SOCKET_STATE_CLIENT_CONNECTED;
592
593         return new_sock;
594
595 failed:
596         DEBUG(0,("TLS init connection failed - %s\n", gnutls_strerror(ret)));
597         tls->tls_enabled = false;
598         return new_sock;
599 }
600
601 static NTSTATUS tls_socket_set_option(struct socket_context *sock, const char *option, const char *val)
602 {
603         set_socket_options(socket_get_fd(sock), option);
604         return NT_STATUS_OK;
605 }
606
607 static char *tls_socket_get_peer_name(struct socket_context *sock, TALLOC_CTX *mem_ctx)
608 {
609         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
610         return socket_get_peer_name(tls->socket, mem_ctx);
611 }
612
613 static struct socket_address *tls_socket_get_peer_addr(struct socket_context *sock, TALLOC_CTX *mem_ctx)
614 {
615         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
616         return socket_get_peer_addr(tls->socket, mem_ctx);
617 }
618
619 static struct socket_address *tls_socket_get_my_addr(struct socket_context *sock, TALLOC_CTX *mem_ctx)
620 {
621         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
622         return socket_get_my_addr(tls->socket, mem_ctx);
623 }
624
625 static int tls_socket_get_fd(struct socket_context *sock)
626 {
627         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
628         return socket_get_fd(tls->socket);
629 }
630
631 static const struct socket_ops tls_socket_ops = {
632         .name                   = "tls",
633         .fn_init                = tls_socket_init,
634         .fn_recv                = tls_socket_recv,
635         .fn_send                = tls_socket_send,
636         .fn_pending             = tls_socket_pending,
637
638         .fn_set_option          = tls_socket_set_option,
639
640         .fn_get_peer_name       = tls_socket_get_peer_name,
641         .fn_get_peer_addr       = tls_socket_get_peer_addr,
642         .fn_get_my_addr         = tls_socket_get_my_addr,
643         .fn_get_fd              = tls_socket_get_fd
644 };
645
646 bool tls_support(struct tls_params *params)
647 {
648         return params->tls_enabled;
649 }
650
651 #else
652
653 /* for systems without tls we just fail the operations, and the caller
654  * will retain the original socket */
655
656 struct tls_params *tls_initialise(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx)
657 {
658         return talloc_new(mem_ctx);
659 }
660
661 /*
662   setup for a new connection
663 */
664 struct socket_context *tls_init_server(struct tls_params *params, 
665                                     struct socket_context *socket,
666                                     struct tevent_fd *fde, 
667                                     const char *plain_chars)
668 {
669         return NULL;
670 }
671
672
673 /*
674   setup for a new client connection
675 */
676 struct socket_context *tls_init_client(struct socket_context *socket,
677                                        struct tevent_fd *fde,
678                                        const char *ca_path)
679 {
680         return NULL;
681 }
682
683 bool tls_support(struct tls_params *params)
684 {
685         return false;
686 }
687
688 #endif
689