r23792: convert Samba4 to GPLv3
[ira/wip.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
28 #if ENABLE_GNUTLS
29 #include "gnutls/gnutls.h"
30
31 #define DH_BITS 1024
32
33 #if defined(HAVE_GNUTLS_DATUM) && !defined(HAVE_GNUTLS_DATUM_T)
34 typedef gnutls_datum gnutls_datum_t;
35 #endif
36
37 /* hold persistent tls data */
38 struct tls_params {
39         gnutls_certificate_credentials x509_cred;
40         gnutls_dh_params dh_params;
41         BOOL tls_enabled;
42 };
43 #endif
44
45 /* hold per connection tls data */
46 struct tls_context {
47         struct socket_context *socket;
48         struct fd_event *fde;
49         BOOL tls_enabled;
50 #if ENABLE_GNUTLS
51         gnutls_session session;
52         BOOL done_handshake;
53         BOOL have_first_byte;
54         uint8_t first_byte;
55         BOOL tls_detect;
56         const char *plain_chars;
57         BOOL output_pending;
58         gnutls_certificate_credentials xcred;
59         BOOL interrupted;
60 #endif
61 };
62
63 BOOL tls_enabled(struct socket_context *sock)
64 {
65         struct tls_context *tls;
66         if (!sock) {
67                 return False;
68         }
69         if (strcmp(sock->backend_name, "tls") != 0) {
70                 return False;
71         }
72         tls = talloc_get_type(sock->private_data, struct tls_context);
73         if (!tls) {
74                 return False;
75         }
76         return tls->tls_enabled;
77 }
78
79
80 #if ENABLE_GNUTLS
81
82 static const struct socket_ops tls_socket_ops;
83
84 static NTSTATUS tls_socket_init(struct socket_context *sock)
85 {
86         switch (sock->type) {
87         case SOCKET_TYPE_STREAM:
88                 break;
89         default:
90                 return NT_STATUS_INVALID_PARAMETER;
91         }
92
93         sock->backend_name = "tls";
94
95         return NT_STATUS_OK;
96 }
97
98 #define TLSCHECK(call) do { \
99         ret = call; \
100         if (ret < 0) { \
101                 DEBUG(0,("TLS %s - %s\n", #call, gnutls_strerror(ret))); \
102                 goto failed; \
103         } \
104 } while (0)
105
106
107 /*
108   callback for reading from a socket
109 */
110 static ssize_t tls_pull(gnutls_transport_ptr ptr, void *buf, size_t size)
111 {
112         struct tls_context *tls = talloc_get_type(ptr, struct tls_context);
113         NTSTATUS status;
114         size_t nread;
115         
116         if (tls->have_first_byte) {
117                 *(uint8_t *)buf = tls->first_byte;
118                 tls->have_first_byte = False;
119                 return 1;
120         }
121
122         status = socket_recv(tls->socket, buf, size, &nread);
123         if (NT_STATUS_EQUAL(status, NT_STATUS_END_OF_FILE)) {
124                 return 0;
125         }
126         if (NT_STATUS_IS_ERR(status)) {
127                 EVENT_FD_NOT_READABLE(tls->fde);
128                 EVENT_FD_NOT_WRITEABLE(tls->fde);
129                 errno = EBADF;
130                 return -1;
131         }
132         if (!NT_STATUS_IS_OK(status)) {
133                 EVENT_FD_READABLE(tls->fde);
134                 errno = EAGAIN;
135                 return -1;
136         }
137         if (tls->output_pending) {
138                 EVENT_FD_WRITEABLE(tls->fde);
139         }
140         if (size != nread) {
141                 EVENT_FD_READABLE(tls->fde);
142         }
143         return nread;
144 }
145
146 /*
147   callback for writing to a socket
148 */
149 static ssize_t tls_push(gnutls_transport_ptr ptr, const void *buf, size_t size)
150 {
151         struct tls_context *tls = talloc_get_type(ptr, struct tls_context);
152         NTSTATUS status;
153         size_t nwritten;
154         DATA_BLOB b;
155
156         if (!tls->tls_enabled) {
157                 return size;
158         }
159
160         b.data = discard_const(buf);
161         b.length = size;
162
163         status = socket_send(tls->socket, &b, &nwritten);
164         if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
165                 errno = EAGAIN;
166                 return -1;
167         }
168         if (!NT_STATUS_IS_OK(status)) {
169                 EVENT_FD_WRITEABLE(tls->fde);
170                 return -1;
171         }
172         if (size != nwritten) {
173                 EVENT_FD_WRITEABLE(tls->fde);
174         }
175         return nwritten;
176 }
177
178 /*
179   destroy a tls session
180  */
181 static int tls_destructor(struct tls_context *tls)
182 {
183         int ret;
184         ret = gnutls_bye(tls->session, GNUTLS_SHUT_WR);
185         if (ret < 0) {
186                 DEBUG(0,("TLS gnutls_bye failed - %s\n", gnutls_strerror(ret)));
187         }
188         return 0;
189 }
190
191
192 /*
193   possibly continue the handshake process
194 */
195 static NTSTATUS tls_handshake(struct tls_context *tls)
196 {
197         int ret;
198
199         if (tls->done_handshake) {
200                 return NT_STATUS_OK;
201         }
202         
203         ret = gnutls_handshake(tls->session);
204         if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
205                 if (gnutls_record_get_direction(tls->session) == 1) {
206                         EVENT_FD_WRITEABLE(tls->fde);
207                 }
208                 return STATUS_MORE_ENTRIES;
209         }
210         if (ret < 0) {
211                 DEBUG(0,("TLS gnutls_handshake failed - %s\n", gnutls_strerror(ret)));
212                 return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
213         }
214         tls->done_handshake = True;
215         return NT_STATUS_OK;
216 }
217
218 /*
219   possibly continue an interrupted operation
220 */
221 static NTSTATUS tls_interrupted(struct tls_context *tls)
222 {
223         int ret;
224
225         if (!tls->interrupted) {
226                 return NT_STATUS_OK;
227         }
228         if (gnutls_record_get_direction(tls->session) == 1) {
229                 ret = gnutls_record_send(tls->session, NULL, 0);
230         } else {
231                 ret = gnutls_record_recv(tls->session, NULL, 0);
232         }
233         if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
234                 return STATUS_MORE_ENTRIES;
235         }
236         tls->interrupted = False;
237         return NT_STATUS_OK;
238 }
239
240 /*
241   see how many bytes are pending on the connection
242 */
243 static NTSTATUS tls_socket_pending(struct socket_context *sock, size_t *npending)
244 {
245         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
246         if (!tls->tls_enabled || tls->tls_detect) {
247                 return socket_pending(tls->socket, npending);
248         }
249         *npending = gnutls_record_check_pending(tls->session);
250         if (*npending == 0) {
251                 NTSTATUS status = socket_pending(tls->socket, npending);
252                 if (*npending == 0) {
253                         /* seems to be a gnutls bug */
254                         (*npending) = 100;
255                 }
256                 return status;
257         }
258         return NT_STATUS_OK;
259 }
260
261 /*
262   receive data either by tls or normal socket_recv
263 */
264 static NTSTATUS tls_socket_recv(struct socket_context *sock, void *buf, 
265                                 size_t wantlen, size_t *nread)
266 {
267         int ret;
268         NTSTATUS status;
269         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
270
271         if (tls->tls_enabled && tls->tls_detect) {
272                 status = socket_recv(tls->socket, &tls->first_byte, 1, nread);
273                 NT_STATUS_NOT_OK_RETURN(status);
274                 if (*nread == 0) return NT_STATUS_OK;
275                 tls->tls_detect = False;
276                 /* look for the first byte of a valid HTTP operation */
277                 if (strchr(tls->plain_chars, tls->first_byte)) {
278                         /* not a tls link */
279                         tls->tls_enabled = False;
280                         *(uint8_t *)buf = tls->first_byte;
281                         return NT_STATUS_OK;
282                 }
283                 tls->have_first_byte = True;
284         }
285
286         if (!tls->tls_enabled) {
287                 return socket_recv(tls->socket, buf, wantlen, nread);
288         }
289
290         status = tls_handshake(tls);
291         NT_STATUS_NOT_OK_RETURN(status);
292
293         status = tls_interrupted(tls);
294         NT_STATUS_NOT_OK_RETURN(status);
295
296         ret = gnutls_record_recv(tls->session, buf, wantlen);
297         if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
298                 if (gnutls_record_get_direction(tls->session) == 1) {
299                         EVENT_FD_WRITEABLE(tls->fde);
300                 }
301                 tls->interrupted = True;
302                 return STATUS_MORE_ENTRIES;
303         }
304         if (ret < 0) {
305                 return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
306         }
307         *nread = ret;
308         return NT_STATUS_OK;
309 }
310
311
312 /*
313   send data either by tls or normal socket_recv
314 */
315 static NTSTATUS tls_socket_send(struct socket_context *sock, 
316                                 const DATA_BLOB *blob, size_t *sendlen)
317 {
318         NTSTATUS status;
319         int ret;
320         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
321
322         if (!tls->tls_enabled) {
323                 return socket_send(tls->socket, blob, sendlen);
324         }
325
326         status = tls_handshake(tls);
327         NT_STATUS_NOT_OK_RETURN(status);
328
329         status = tls_interrupted(tls);
330         NT_STATUS_NOT_OK_RETURN(status);
331
332         ret = gnutls_record_send(tls->session, blob->data, blob->length);
333         if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
334                 if (gnutls_record_get_direction(tls->session) == 1) {
335                         EVENT_FD_WRITEABLE(tls->fde);
336                 }
337                 tls->interrupted = True;
338                 return STATUS_MORE_ENTRIES;
339         }
340         if (ret < 0) {
341                 DEBUG(0,("gnutls_record_send of %d failed - %s\n", (int)blob->length, gnutls_strerror(ret)));
342                 return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
343         }
344         *sendlen = ret;
345         tls->output_pending = (ret < blob->length);
346         return NT_STATUS_OK;
347 }
348
349
350 /*
351   initialise global tls state
352 */
353 struct tls_params *tls_initialise(TALLOC_CTX *mem_ctx)
354 {
355         struct tls_params *params;
356         int ret;
357         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
358         const char *keyfile = private_path(tmp_ctx, lp_tls_keyfile());
359         const char *certfile = private_path(tmp_ctx, lp_tls_certfile());
360         const char *cafile = private_path(tmp_ctx, lp_tls_cafile());
361         const char *crlfile = private_path(tmp_ctx, lp_tls_crlfile());
362         const char *dhpfile = private_path(tmp_ctx, lp_tls_dhpfile());
363         void tls_cert_generate(TALLOC_CTX *, const char *, const char *, const char *);
364
365         params = talloc(mem_ctx, struct tls_params);
366         if (params == NULL) {
367                 talloc_free(tmp_ctx);
368                 return NULL;
369         }
370
371         if (!lp_tls_enabled() || keyfile == NULL || *keyfile == 0) {
372                 params->tls_enabled = False;
373                 talloc_free(tmp_ctx);
374                 return params;
375         }
376
377         if (!file_exist(cafile)) {
378                 tls_cert_generate(params, keyfile, certfile, cafile);
379         }
380
381         ret = gnutls_global_init();
382         if (ret < 0) goto init_failed;
383
384         gnutls_certificate_allocate_credentials(&params->x509_cred);
385         if (ret < 0) goto init_failed;
386
387         if (cafile && *cafile) {
388                 ret = gnutls_certificate_set_x509_trust_file(params->x509_cred, cafile, 
389                                                              GNUTLS_X509_FMT_PEM);      
390                 if (ret < 0) {
391                         DEBUG(0,("TLS failed to initialise cafile %s\n", cafile));
392                         goto init_failed;
393                 }
394         }
395
396         if (crlfile && *crlfile) {
397                 ret = gnutls_certificate_set_x509_crl_file(params->x509_cred, 
398                                                            crlfile, 
399                                                            GNUTLS_X509_FMT_PEM);
400                 if (ret < 0) {
401                         DEBUG(0,("TLS failed to initialise crlfile %s\n", crlfile));
402                         goto init_failed;
403                 }
404         }
405         
406         ret = gnutls_certificate_set_x509_key_file(params->x509_cred, 
407                                                    certfile, keyfile,
408                                                    GNUTLS_X509_FMT_PEM);
409         if (ret < 0) {
410                 DEBUG(0,("TLS failed to initialise certfile %s and keyfile %s\n", 
411                          certfile, keyfile));
412                 goto init_failed;
413         }
414         
415         
416         ret = gnutls_dh_params_init(&params->dh_params);
417         if (ret < 0) goto init_failed;
418
419         if (dhpfile && *dhpfile) {
420                 gnutls_datum_t dhparms;
421                 size_t size;
422                 dhparms.data = (uint8_t *)file_load(dhpfile, &size, mem_ctx);
423
424                 if (!dhparms.data) {
425                         DEBUG(0,("Failed to read DH Parms from %s\n", dhpfile));
426                         goto init_failed;
427                 }
428                 dhparms.size = size;
429                         
430                 ret = gnutls_dh_params_import_pkcs3(params->dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
431                 if (ret < 0) goto init_failed;
432         } else {
433                 ret = gnutls_dh_params_generate2(params->dh_params, DH_BITS);
434                 if (ret < 0) goto init_failed;
435         }
436                 
437         gnutls_certificate_set_dh_params(params->x509_cred, params->dh_params);
438
439         params->tls_enabled = True;
440
441         talloc_free(tmp_ctx);
442         return params;
443
444 init_failed:
445         DEBUG(0,("GNUTLS failed to initialise - %s\n", gnutls_strerror(ret)));
446         params->tls_enabled = False;
447         talloc_free(tmp_ctx);
448         return params;
449 }
450
451
452 /*
453   setup for a new connection
454 */
455 struct socket_context *tls_init_server(struct tls_params *params, 
456                                        struct socket_context *socket,
457                                        struct fd_event *fde, 
458                                        const char *plain_chars)
459 {
460         struct tls_context *tls;
461         int ret;
462         struct socket_context *new_sock;
463         NTSTATUS nt_status;
464         
465         nt_status = socket_create_with_ops(socket, &tls_socket_ops, &new_sock, 
466                                            SOCKET_TYPE_STREAM, 
467                                            socket->flags | SOCKET_FLAG_ENCRYPT);
468         if (!NT_STATUS_IS_OK(nt_status)) {
469                 return NULL;
470         }
471
472         tls = talloc(new_sock, struct tls_context);
473         if (tls == NULL) {
474                 return NULL;
475         }
476
477         tls->socket          = socket;
478         tls->fde             = fde;
479         if (talloc_reference(tls, fde) == NULL) {
480                 talloc_free(new_sock);
481                 return NULL;
482         }
483         if (talloc_reference(tls, socket) == NULL) {
484                 talloc_free(new_sock);
485                 return NULL;
486         }
487
488         new_sock->private_data    = tls;
489
490         if (!params->tls_enabled) {
491                 talloc_free(new_sock);
492                 return NULL;
493         }
494
495         TLSCHECK(gnutls_init(&tls->session, GNUTLS_SERVER));
496
497         talloc_set_destructor(tls, tls_destructor);
498
499         TLSCHECK(gnutls_set_default_priority(tls->session));
500         TLSCHECK(gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, 
501                                         params->x509_cred));
502         gnutls_certificate_server_set_request(tls->session, GNUTLS_CERT_REQUEST);
503         gnutls_dh_set_prime_bits(tls->session, DH_BITS);
504         gnutls_transport_set_ptr(tls->session, (gnutls_transport_ptr)tls);
505         gnutls_transport_set_pull_function(tls->session, (gnutls_pull_func)tls_pull);
506         gnutls_transport_set_push_function(tls->session, (gnutls_push_func)tls_push);
507         gnutls_transport_set_lowat(tls->session, 0);
508
509         tls->plain_chars = plain_chars;
510         if (plain_chars) {
511                 tls->tls_detect = True;
512         } else {
513                 tls->tls_detect = False;
514         }
515
516         tls->output_pending  = False;
517         tls->done_handshake  = False;
518         tls->have_first_byte = False;
519         tls->tls_enabled     = True;
520         tls->interrupted     = False;
521         
522         new_sock->state = SOCKET_STATE_SERVER_CONNECTED;
523
524         return new_sock;
525
526 failed:
527         DEBUG(0,("TLS init connection failed - %s\n", gnutls_strerror(ret)));
528         talloc_free(new_sock);
529         return NULL;
530 }
531
532
533 /*
534   setup for a new client connection
535 */
536 struct socket_context *tls_init_client(struct socket_context *socket,
537                                        struct fd_event *fde)
538 {
539         struct tls_context *tls;
540         int ret = 0;
541         const int cert_type_priority[] = { GNUTLS_CRT_X509, GNUTLS_CRT_OPENPGP, 0 };
542         char *cafile;
543         struct socket_context *new_sock;
544         NTSTATUS nt_status;
545         
546         nt_status = socket_create_with_ops(socket, &tls_socket_ops, &new_sock, 
547                                            SOCKET_TYPE_STREAM, 
548                                            socket->flags | SOCKET_FLAG_ENCRYPT);
549         if (!NT_STATUS_IS_OK(nt_status)) {
550                 return NULL;
551         }
552
553         tls = talloc(new_sock, struct tls_context);
554         if (tls == NULL) return NULL;
555
556         tls->socket          = socket;
557         tls->fde             = fde;
558         if (talloc_reference(tls, fde) == NULL) {
559                 return NULL;
560         }
561         if (talloc_reference(tls, socket) == NULL) {
562                 return NULL;
563         }
564         new_sock->private_data    = tls;
565
566         cafile = private_path(tls, lp_tls_cafile());
567         if (!cafile || !*cafile) {
568                 goto failed;
569         }
570
571         gnutls_global_init();
572
573         gnutls_certificate_allocate_credentials(&tls->xcred);
574         gnutls_certificate_set_x509_trust_file(tls->xcred, cafile, GNUTLS_X509_FMT_PEM);
575         talloc_free(cafile);
576         TLSCHECK(gnutls_init(&tls->session, GNUTLS_CLIENT));
577         TLSCHECK(gnutls_set_default_priority(tls->session));
578         gnutls_certificate_type_set_priority(tls->session, cert_type_priority);
579         TLSCHECK(gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, tls->xcred));
580
581         talloc_set_destructor(tls, tls_destructor);
582
583         gnutls_transport_set_ptr(tls->session, (gnutls_transport_ptr)tls);
584         gnutls_transport_set_pull_function(tls->session, (gnutls_pull_func)tls_pull);
585         gnutls_transport_set_push_function(tls->session, (gnutls_push_func)tls_push);
586         gnutls_transport_set_lowat(tls->session, 0);
587         tls->tls_detect = False;
588
589         tls->output_pending  = False;
590         tls->done_handshake  = False;
591         tls->have_first_byte = False;
592         tls->tls_enabled     = True;
593         tls->interrupted     = False;
594         
595         new_sock->state = SOCKET_STATE_CLIENT_CONNECTED;
596
597         return new_sock;
598
599 failed:
600         DEBUG(0,("TLS init connection failed - %s\n", gnutls_strerror(ret)));
601         tls->tls_enabled = False;
602         return new_sock;
603 }
604
605 static NTSTATUS tls_socket_set_option(struct socket_context *sock, const char *option, const char *val)
606 {
607         set_socket_options(socket_get_fd(sock), option);
608         return NT_STATUS_OK;
609 }
610
611 static char *tls_socket_get_peer_name(struct socket_context *sock, TALLOC_CTX *mem_ctx)
612 {
613         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
614         return socket_get_peer_name(tls->socket, mem_ctx);
615 }
616
617 static struct socket_address *tls_socket_get_peer_addr(struct socket_context *sock, TALLOC_CTX *mem_ctx)
618 {
619         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
620         return socket_get_peer_addr(tls->socket, mem_ctx);
621 }
622
623 static struct socket_address *tls_socket_get_my_addr(struct socket_context *sock, TALLOC_CTX *mem_ctx)
624 {
625         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
626         return socket_get_my_addr(tls->socket, mem_ctx);
627 }
628
629 static int tls_socket_get_fd(struct socket_context *sock)
630 {
631         struct tls_context *tls = talloc_get_type(sock->private_data, struct tls_context);
632         return socket_get_fd(tls->socket);
633 }
634
635 static const struct socket_ops tls_socket_ops = {
636         .name                   = "tls",
637         .fn_init                = tls_socket_init,
638         .fn_recv                = tls_socket_recv,
639         .fn_send                = tls_socket_send,
640         .fn_pending             = tls_socket_pending,
641
642         .fn_set_option          = tls_socket_set_option,
643
644         .fn_get_peer_name       = tls_socket_get_peer_name,
645         .fn_get_peer_addr       = tls_socket_get_peer_addr,
646         .fn_get_my_addr         = tls_socket_get_my_addr,
647         .fn_get_fd              = tls_socket_get_fd
648 };
649
650 BOOL tls_support(struct tls_params *params)
651 {
652         return params->tls_enabled;
653 }
654
655 #else
656
657 /* for systems without tls we just fail the operations, and the caller
658  * will retain the original socket */
659
660 struct tls_params *tls_initialise(TALLOC_CTX *mem_ctx)
661 {
662         return talloc_new(mem_ctx);
663 }
664
665 /*
666   setup for a new connection
667 */
668 struct socket_context *tls_init_server(struct tls_params *params, 
669                                     struct socket_context *socket,
670                                     struct fd_event *fde, 
671                                     const char *plain_chars)
672 {
673         return NULL;
674 }
675
676
677 /*
678   setup for a new client connection
679 */
680 struct socket_context *tls_init_client(struct socket_context *socket,
681                                        struct fd_event *fde)
682 {
683         return NULL;
684 }
685
686 BOOL tls_support(struct tls_params *params)
687 {
688         return False;
689 }
690
691 #endif
692