Test suite: disable OCSP for old openssl part 3
[exim.git] / src / src / tls-openssl.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2014 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Portions Copyright (c) The OpenSSL Project 1999 */
9
10 /* This module provides the TLS (aka SSL) support for Exim using the OpenSSL
11 library. It is #included into the tls.c file when that library is used. The
12 code herein is based on a patch that was originally contributed by Steve
13 Haslam. It was adapted from stunnel, a GPL program by Michal Trojnara.
14
15 No cryptographic code is included in Exim. All this module does is to call
16 functions from the OpenSSL library. */
17
18
19 /* Heading stuff */
20
21 #include <openssl/lhash.h>
22 #include <openssl/ssl.h>
23 #include <openssl/err.h>
24 #include <openssl/rand.h>
25 #ifndef DISABLE_OCSP
26 # include <openssl/ocsp.h>
27 #endif
28 #ifdef EXPERIMENTAL_DANE
29 # include <danessl.h>
30 #endif
31
32
33 #ifndef DISABLE_OCSP
34 # define EXIM_OCSP_SKEW_SECONDS (300L)
35 # define EXIM_OCSP_MAX_AGE (-1L)
36 #endif
37
38 #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
39 # define EXIM_HAVE_OPENSSL_TLSEXT
40 #endif
41 #if OPENSSL_VERSION_NUMBER >= 0x010100000L
42 # define EXIM_HAVE_OPENSSL_CHECKHOST
43 #endif
44 #if OPENSSL_VERSION_NUMBER >= 0x010000000L \
45 && (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L
46 # define EXIM_HAVE_OPENSSL_CHECKHOST
47 #endif
48
49 #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP)
50 # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile"
51 # define DISABLE_OCSP
52 #endif
53
54 /* Structure for collecting random data for seeding. */
55
56 typedef struct randstuff {
57 struct timeval tv;
58 pid_t p;
59 } randstuff;
60
61 /* Local static variables */
62
63 static BOOL client_verify_callback_called = FALSE;
64 static BOOL server_verify_callback_called = FALSE;
65 static const uschar *sid_ctx = US"exim";
66
67 /* We have three different contexts to care about.
68
69 Simple case: client, `client_ctx`
70 As a client, we can be doing a callout or cut-through delivery while receiving
71 a message. So we have a client context, which should have options initialised
72 from the SMTP Transport.
73
74 Server:
75 There are two cases: with and without ServerNameIndication from the client.
76 Given TLS SNI, we can be using different keys, certs and various other
77 configuration settings, because they're re-expanded with $tls_sni set. This
78 allows vhosting with TLS. This SNI is sent in the handshake.
79 A client might not send SNI, so we need a fallback, and an initial setup too.
80 So as a server, we start out using `server_ctx`.
81 If SNI is sent by the client, then we as server, mid-negotiation, try to clone
82 `server_sni` from `server_ctx` and then initialise settings by re-expanding
83 configuration.
84 */
85
86 static SSL_CTX *client_ctx = NULL;
87 static SSL_CTX *server_ctx = NULL;
88 static SSL *client_ssl = NULL;
89 static SSL *server_ssl = NULL;
90
91 #ifdef EXIM_HAVE_OPENSSL_TLSEXT
92 static SSL_CTX *server_sni = NULL;
93 #endif
94
95 static char ssl_errstring[256];
96
97 static int ssl_session_timeout = 200;
98 static BOOL client_verify_optional = FALSE;
99 static BOOL server_verify_optional = FALSE;
100
101 static BOOL reexpand_tls_files_for_sni = FALSE;
102
103
104 typedef struct tls_ext_ctx_cb {
105 uschar *certificate;
106 uschar *privatekey;
107 #ifndef DISABLE_OCSP
108 BOOL is_server;
109 union {
110 struct {
111 uschar *file;
112 uschar *file_expanded;
113 OCSP_RESPONSE *response;
114 } server;
115 struct {
116 X509_STORE *verify_store; /* non-null if status requested */
117 BOOL verify_required;
118 } client;
119 } u_ocsp;
120 #endif
121 uschar *dhparam;
122 /* these are cached from first expand */
123 uschar *server_cipher_list;
124 /* only passed down to tls_error: */
125 host_item *host;
126
127 #ifdef EXPERIMENTAL_CERTNAMES
128 uschar * verify_cert_hostnames;
129 #endif
130 #ifdef EXPERIMENTAL_EVENT
131 uschar * event_action;
132 #endif
133 } tls_ext_ctx_cb;
134
135 /* should figure out a cleanup of API to handle state preserved per
136 implementation, for various reasons, which can be void * in the APIs.
137 For now, we hack around it. */
138 tls_ext_ctx_cb *client_static_cbinfo = NULL;
139 tls_ext_ctx_cb *server_static_cbinfo = NULL;
140
141 static int
142 setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
143 int (*cert_vfy_cb)(int, X509_STORE_CTX *) );
144
145 /* Callbacks */
146 #ifdef EXIM_HAVE_OPENSSL_TLSEXT
147 static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg);
148 #endif
149 #ifndef DISABLE_OCSP
150 static int tls_server_stapling_cb(SSL *s, void *arg);
151 #endif
152
153
154 /*************************************************
155 * Handle TLS error *
156 *************************************************/
157
158 /* Called from lots of places when errors occur before actually starting to do
159 the TLS handshake, that is, while the session is still in clear. Always returns
160 DEFER for a server and FAIL for a client so that most calls can use "return
161 tls_error(...)" to do this processing and then give an appropriate return. A
162 single function is used for both server and client, because it is called from
163 some shared functions.
164
165 Argument:
166 prefix text to include in the logged error
167 host NULL if setting up a server;
168 the connected host if setting up a client
169 msg error message or NULL if we should ask OpenSSL
170
171 Returns: OK/DEFER/FAIL
172 */
173
174 static int
175 tls_error(uschar *prefix, host_item *host, uschar *msg)
176 {
177 if (!msg)
178 {
179 ERR_error_string(ERR_get_error(), ssl_errstring);
180 msg = (uschar *)ssl_errstring;
181 }
182
183 if (host)
184 {
185 log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection (%s): %s",
186 host->name, host->address, prefix, msg);
187 return FAIL;
188 }
189 else
190 {
191 uschar *conn_info = smtp_get_connection_info();
192 if (Ustrncmp(conn_info, US"SMTP ", 5) == 0)
193 conn_info += 5;
194 /* I'd like to get separated H= here, but too hard for now */
195 log_write(0, LOG_MAIN, "TLS error on %s (%s): %s",
196 conn_info, prefix, msg);
197 return DEFER;
198 }
199 }
200
201
202
203 /*************************************************
204 * Callback to generate RSA key *
205 *************************************************/
206
207 /*
208 Arguments:
209 s SSL connection
210 export not used
211 keylength keylength
212
213 Returns: pointer to generated key
214 */
215
216 static RSA *
217 rsa_callback(SSL *s, int export, int keylength)
218 {
219 RSA *rsa_key;
220 export = export; /* Shut picky compilers up */
221 DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength);
222 rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL);
223 if (rsa_key == NULL)
224 {
225 ERR_error_string(ERR_get_error(), ssl_errstring);
226 log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s",
227 ssl_errstring);
228 return NULL;
229 }
230 return rsa_key;
231 }
232
233
234
235 /* Extreme debug
236 #ifndef DISABLE_OCSP
237 void
238 x509_store_dump_cert_s_names(X509_STORE * store)
239 {
240 STACK_OF(X509_OBJECT) * roots= store->objs;
241 int i;
242 static uschar name[256];
243
244 for(i= 0; i<sk_X509_OBJECT_num(roots); i++)
245 {
246 X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i);
247 if(tmp_obj->type == X509_LU_X509)
248 {
249 X509 * current_cert= tmp_obj->data.x509;
250 X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name));
251 debug_printf(" %s\n", name);
252 }
253 }
254 }
255 #endif
256 */
257
258
259 /*************************************************
260 * Callback for verification *
261 *************************************************/
262
263 /* The SSL library does certificate verification if set up to do so. This
264 callback has the current yes/no state is in "state". If verification succeeded,
265 we set up the tls_peerdn string. If verification failed, what happens depends
266 on whether the client is required to present a verifiable certificate or not.
267
268 If verification is optional, we change the state to yes, but still log the
269 verification error. For some reason (it really would help to have proper
270 documentation of OpenSSL), this callback function then gets called again, this
271 time with state = 1. In fact, that's useful, because we can set up the peerdn
272 value, but we must take care not to set the private verified flag on the second
273 time through.
274
275 Note: this function is not called if the client fails to present a certificate
276 when asked. We get here only if a certificate has been received. Handling of
277 optional verification for this case is done when requesting SSL to verify, by
278 setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case.
279
280 May be called multiple times for different issues with a certificate, even
281 for a given "depth" in the certificate chain.
282
283 Arguments:
284 state current yes/no state as 1/0
285 x509ctx certificate information.
286 client TRUE for client startup, FALSE for server startup
287
288 Returns: 1 if verified, 0 if not
289 */
290
291 static int
292 verify_callback(int state, X509_STORE_CTX *x509ctx,
293 tls_support *tlsp, BOOL *calledp, BOOL *optionalp)
294 {
295 X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
296 int depth = X509_STORE_CTX_get_error_depth(x509ctx);
297 static uschar txt[256];
298 #ifdef EXPERIMENTAL_EVENT
299 uschar * ev;
300 uschar * yield;
301 #endif
302
303 X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt));
304
305 if (state == 0)
306 {
307 log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s",
308 depth,
309 X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)),
310 txt);
311 tlsp->certificate_verified = FALSE;
312 *calledp = TRUE;
313 if (!*optionalp)
314 {
315 tlsp->peercert = X509_dup(cert);
316 return 0; /* reject */
317 }
318 DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
319 "tls_try_verify_hosts)\n");
320 }
321
322 else if (depth != 0)
323 {
324 DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, txt);
325 #ifndef DISABLE_OCSP
326 if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store)
327 { /* client, wanting stapling */
328 /* Add the server cert's signing chain as the one
329 for the verification of the OCSP stapled information. */
330
331 if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store,
332 cert))
333 ERR_clear_error();
334 }
335 #endif
336 #ifdef EXPERIMENTAL_EVENT
337 ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action;
338 if (ev)
339 {
340 tlsp->peercert = X509_dup(cert);
341 if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth))))
342 {
343 log_write(0, LOG_MAIN, "SSL verify denied by event-action: "
344 "depth=%d cert=%s: %s", depth, txt, yield);
345 tlsp->certificate_verified = FALSE;
346 *calledp = TRUE;
347 return 0; /* reject */
348 }
349 X509_free(tlsp->peercert);
350 tlsp->peercert = NULL;
351 }
352 #endif
353 }
354 else
355 {
356 #ifdef EXPERIMENTAL_CERTNAMES
357 uschar * verify_cert_hostnames;
358 #endif
359
360 tlsp->peerdn = txt;
361 tlsp->peercert = X509_dup(cert);
362
363 #ifdef EXPERIMENTAL_CERTNAMES
364 if ( tlsp == &tls_out
365 && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames)))
366 /* client, wanting hostname check */
367
368 # if EXIM_HAVE_OPENSSL_CHECKHOST
369 # ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
370 # define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0
371 # endif
372 {
373 int sep = 0;
374 uschar * list = verify_cert_hostnames;
375 uschar * name;
376 int rc;
377 while ((name = string_nextinlist(&list, &sep, NULL, 0)))
378 if ((rc = X509_check_host(cert, name, 0,
379 X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)))
380 {
381 if (rc < 0)
382 {
383 log_write(0, LOG_MAIN, "SSL verify error: internal error\n");
384 name = NULL;
385 }
386 break;
387 }
388 if (!name)
389 {
390 log_write(0, LOG_MAIN,
391 "SSL verify error: certificate name mismatch: \"%s\"\n", txt);
392 return 0; /* reject */
393 }
394 }
395 # else
396 if (!tls_is_name_for_cert(verify_cert_hostnames, cert))
397 {
398 log_write(0, LOG_MAIN,
399 "SSL verify error: certificate name mismatch: \"%s\"\n", txt);
400 return 0; /* reject */
401 }
402 # endif
403 #endif /*EXPERIMENTAL_CERTNAMES*/
404
405 #ifdef EXPERIMENTAL_EVENT
406 ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action;
407 if (ev)
408 if ((yield = event_raise(ev, US"tls:cert", US"0")))
409 {
410 log_write(0, LOG_MAIN, "SSL verify denied by event-action: "
411 "depth=0 cert=%s: %s", txt, yield);
412 tlsp->certificate_verified = FALSE;
413 *calledp = TRUE;
414 return 0; /* reject */
415 }
416 #endif
417
418 DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n",
419 *calledp ? "" : " authenticated", txt);
420 if (!*calledp) tlsp->certificate_verified = TRUE;
421 *calledp = TRUE;
422 }
423
424 return 1; /* accept, at least for this level */
425 }
426
427 static int
428 verify_callback_client(int state, X509_STORE_CTX *x509ctx)
429 {
430 return verify_callback(state, x509ctx, &tls_out, &client_verify_callback_called, &client_verify_optional);
431 }
432
433 static int
434 verify_callback_server(int state, X509_STORE_CTX *x509ctx)
435 {
436 return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, &server_verify_optional);
437 }
438
439
440 #ifdef EXPERIMENTAL_DANE
441
442 /* This gets called *by* the dane library verify callback, which interposes
443 itself.
444 */
445 static int
446 verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx)
447 {
448 X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
449 static uschar txt[256];
450 #ifdef EXPERIMENTAL_EVENT
451 int depth = X509_STORE_CTX_get_error_depth(x509ctx);
452 uschar * yield;
453 #endif
454
455 X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt));
456
457 DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s\n", txt);
458 tls_out.peerdn = txt;
459 tls_out.peercert = X509_dup(cert);
460
461 #ifdef EXPERIMENTAL_EVENT
462 if (client_static_cbinfo->event_action)
463 {
464 if ((yield = event_raise(client_static_cbinfo->event_action,
465 US"tls:cert", string_sprintf("%d", depth))))
466 {
467 log_write(0, LOG_MAIN, "DANE verify denied by event-action: "
468 "depth=%d cert=%s: %s", depth, txt, yield);
469 tls_out.certificate_verified = FALSE;
470 return 0; /* reject */
471 }
472 if (depth != 0)
473 {
474 X509_free(tls_out.peercert);
475 tls_out.peercert = NULL;
476 }
477 }
478 #endif
479
480 if (state == 1)
481 tls_out.dane_verified =
482 tls_out.certificate_verified = TRUE;
483 return 1;
484 }
485
486 #endif /*EXPERIMENTAL_DANE*/
487
488
489 /*************************************************
490 * Information callback *
491 *************************************************/
492
493 /* The SSL library functions call this from time to time to indicate what they
494 are doing. We copy the string to the debugging output when TLS debugging has
495 been requested.
496
497 Arguments:
498 s the SSL connection
499 where
500 ret
501
502 Returns: nothing
503 */
504
505 static void
506 info_callback(SSL *s, int where, int ret)
507 {
508 where = where;
509 ret = ret;
510 DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s));
511 }
512
513
514
515 /*************************************************
516 * Initialize for DH *
517 *************************************************/
518
519 /* If dhparam is set, expand it, and load up the parameters for DH encryption.
520
521 Arguments:
522 dhparam DH parameter file or fixed parameter identity string
523 host connected host, if client; NULL if server
524
525 Returns: TRUE if OK (nothing to set up, or setup worked)
526 */
527
528 static BOOL
529 init_dh(SSL_CTX *sctx, uschar *dhparam, host_item *host)
530 {
531 BIO *bio;
532 DH *dh;
533 uschar *dhexpanded;
534 const char *pem;
535
536 if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded))
537 return FALSE;
538
539 if (!dhexpanded || !*dhexpanded)
540 bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1);
541 else if (dhexpanded[0] == '/')
542 {
543 if (!(bio = BIO_new_file(CS dhexpanded, "r")))
544 {
545 tls_error(string_sprintf("could not read dhparams file %s", dhexpanded),
546 host, US strerror(errno));
547 return FALSE;
548 }
549 }
550 else
551 {
552 if (Ustrcmp(dhexpanded, "none") == 0)
553 {
554 DEBUG(D_tls) debug_printf("Requested no DH parameters.\n");
555 return TRUE;
556 }
557
558 if (!(pem = std_dh_prime_named(dhexpanded)))
559 {
560 tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded),
561 host, US strerror(errno));
562 return FALSE;
563 }
564 bio = BIO_new_mem_buf(CS pem, -1);
565 }
566
567 if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL)))
568 {
569 BIO_free(bio);
570 tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded),
571 host, NULL);
572 return FALSE;
573 }
574
575 /* Even if it is larger, we silently return success rather than cause things
576 * to fail out, so that a too-large DH will not knock out all TLS; it's a
577 * debatable choice. */
578 if ((8*DH_size(dh)) > tls_dh_max_bits)
579 {
580 DEBUG(D_tls)
581 debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d",
582 8*DH_size(dh), tls_dh_max_bits);
583 }
584 else
585 {
586 SSL_CTX_set_tmp_dh(sctx, dh);
587 DEBUG(D_tls)
588 debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n",
589 dhexpanded ? dhexpanded : US"default", 8*DH_size(dh));
590 }
591
592 DH_free(dh);
593 BIO_free(bio);
594
595 return TRUE;
596 }
597
598
599
600
601 #ifndef DISABLE_OCSP
602 /*************************************************
603 * Load OCSP information into state *
604 *************************************************/
605
606 /* Called to load the server OCSP response from the given file into memory, once
607 caller has determined this is needed. Checks validity. Debugs a message
608 if invalid.
609
610 ASSUMES: single response, for single cert.
611
612 Arguments:
613 sctx the SSL_CTX* to update
614 cbinfo various parts of session state
615 expanded the filename putatively holding an OCSP response
616
617 */
618
619 static void
620 ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded)
621 {
622 BIO *bio;
623 OCSP_RESPONSE *resp;
624 OCSP_BASICRESP *basic_response;
625 OCSP_SINGLERESP *single_response;
626 ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
627 X509_STORE *store;
628 unsigned long verify_flags;
629 int status, reason, i;
630
631 cbinfo->u_ocsp.server.file_expanded = string_copy(expanded);
632 if (cbinfo->u_ocsp.server.response)
633 {
634 OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response);
635 cbinfo->u_ocsp.server.response = NULL;
636 }
637
638 bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb");
639 if (!bio)
640 {
641 DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n",
642 cbinfo->u_ocsp.server.file_expanded);
643 return;
644 }
645
646 resp = d2i_OCSP_RESPONSE_bio(bio, NULL);
647 BIO_free(bio);
648 if (!resp)
649 {
650 DEBUG(D_tls) debug_printf("Error reading OCSP response.\n");
651 return;
652 }
653
654 status = OCSP_response_status(resp);
655 if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL)
656 {
657 DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n",
658 OCSP_response_status_str(status), status);
659 goto bad;
660 }
661
662 basic_response = OCSP_response_get1_basic(resp);
663 if (!basic_response)
664 {
665 DEBUG(D_tls)
666 debug_printf("OCSP response parse error: unable to extract basic response.\n");
667 goto bad;
668 }
669
670 store = SSL_CTX_get_cert_store(sctx);
671 verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */
672
673 /* May need to expose ability to adjust those flags?
674 OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT
675 OCSP_TRUSTOTHER OCSP_NOINTERN */
676
677 i = OCSP_basic_verify(basic_response, NULL, store, verify_flags);
678 if (i <= 0)
679 {
680 DEBUG(D_tls) {
681 ERR_error_string(ERR_get_error(), ssl_errstring);
682 debug_printf("OCSP response verify failure: %s\n", US ssl_errstring);
683 }
684 goto bad;
685 }
686
687 /* Here's the simplifying assumption: there's only one response, for the
688 one certificate we use, and nothing for anything else in a chain. If this
689 proves false, we need to extract a cert id from our issued cert
690 (tls_certificate) and use that for OCSP_resp_find_status() (which finds the
691 right cert in the stack and then calls OCSP_single_get0_status()).
692
693 I'm hoping to avoid reworking a bunch more of how we handle state here. */
694 single_response = OCSP_resp_get0(basic_response, 0);
695 if (!single_response)
696 {
697 DEBUG(D_tls)
698 debug_printf("Unable to get first response from OCSP basic response.\n");
699 goto bad;
700 }
701
702 status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd);
703 if (status != V_OCSP_CERTSTATUS_GOOD)
704 {
705 DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n",
706 OCSP_cert_status_str(status), status,
707 OCSP_crl_reason_str(reason), reason);
708 goto bad;
709 }
710
711 if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
712 {
713 DEBUG(D_tls) debug_printf("OCSP status invalid times.\n");
714 goto bad;
715 }
716
717 supply_response:
718 cbinfo->u_ocsp.server.response = resp;
719 return;
720
721 bad:
722 if (running_in_test_harness)
723 {
724 extern char ** environ;
725 uschar ** p;
726 for (p = USS environ; *p != NULL; p++)
727 if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0)
728 {
729 DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n");
730 goto supply_response;
731 }
732 }
733 return;
734 }
735 #endif /*!DISABLE_OCSP*/
736
737
738
739
740 /*************************************************
741 * Expand key and cert file specs *
742 *************************************************/
743
744 /* Called once during tls_init and possibly again during TLS setup, for a
745 new context, if Server Name Indication was used and tls_sni was seen in
746 the certificate string.
747
748 Arguments:
749 sctx the SSL_CTX* to update
750 cbinfo various parts of session state
751
752 Returns: OK/DEFER/FAIL
753 */
754
755 static int
756 tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo)
757 {
758 uschar *expanded;
759
760 if (cbinfo->certificate == NULL)
761 return OK;
762
763 if (Ustrstr(cbinfo->certificate, US"tls_sni") ||
764 Ustrstr(cbinfo->certificate, US"tls_in_sni") ||
765 Ustrstr(cbinfo->certificate, US"tls_out_sni")
766 )
767 reexpand_tls_files_for_sni = TRUE;
768
769 if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded))
770 return DEFER;
771
772 if (expanded != NULL)
773 {
774 DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded);
775 if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded))
776 return tls_error(string_sprintf(
777 "SSL_CTX_use_certificate_chain_file file=%s", expanded),
778 cbinfo->host, NULL);
779 }
780
781 if (cbinfo->privatekey != NULL &&
782 !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded))
783 return DEFER;
784
785 /* If expansion was forced to fail, key_expanded will be NULL. If the result
786 of the expansion is an empty string, ignore it also, and assume the private
787 key is in the same file as the certificate. */
788
789 if (expanded != NULL && *expanded != 0)
790 {
791 DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded);
792 if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM))
793 return tls_error(string_sprintf(
794 "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL);
795 }
796
797 #ifndef DISABLE_OCSP
798 if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL)
799 {
800 if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded))
801 return DEFER;
802
803 if (expanded != NULL && *expanded != 0)
804 {
805 DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded);
806 if (cbinfo->u_ocsp.server.file_expanded &&
807 (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0))
808 {
809 DEBUG(D_tls)
810 debug_printf("tls_ocsp_file value unchanged, using existing values.\n");
811 } else {
812 ocsp_load_response(sctx, cbinfo, expanded);
813 }
814 }
815 }
816 #endif
817
818 return OK;
819 }
820
821
822
823
824 /*************************************************
825 * Callback to handle SNI *
826 *************************************************/
827
828 /* Called when acting as server during the TLS session setup if a Server Name
829 Indication extension was sent by the client.
830
831 API documentation is OpenSSL s_server.c implementation.
832
833 Arguments:
834 s SSL* of the current session
835 ad unknown (part of OpenSSL API) (unused)
836 arg Callback of "our" registered data
837
838 Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK}
839 */
840
841 #ifdef EXIM_HAVE_OPENSSL_TLSEXT
842 static int
843 tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg)
844 {
845 const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name);
846 tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
847 int rc;
848 int old_pool = store_pool;
849
850 if (!servername)
851 return SSL_TLSEXT_ERR_OK;
852
853 DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername,
854 reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)");
855
856 /* Make the extension value available for expansion */
857 store_pool = POOL_PERM;
858 tls_in.sni = string_copy(US servername);
859 store_pool = old_pool;
860
861 if (!reexpand_tls_files_for_sni)
862 return SSL_TLSEXT_ERR_OK;
863
864 /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually;
865 not confident that memcpy wouldn't break some internal reference counting.
866 Especially since there's a references struct member, which would be off. */
867
868 if (!(server_sni = SSL_CTX_new(SSLv23_server_method())))
869 {
870 ERR_error_string(ERR_get_error(), ssl_errstring);
871 DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring);
872 return SSL_TLSEXT_ERR_NOACK;
873 }
874
875 /* Not sure how many of these are actually needed, since SSL object
876 already exists. Might even need this selfsame callback, for reneg? */
877
878 SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx));
879 SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx));
880 SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx));
881 SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx));
882 SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb);
883 SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo);
884 if (cbinfo->server_cipher_list)
885 SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list);
886 #ifndef DISABLE_OCSP
887 if (cbinfo->u_ocsp.server.file)
888 {
889 SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb);
890 SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo);
891 }
892 #endif
893
894 rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server);
895 if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
896
897 /* do this after setup_certs, because this can require the certs for verifying
898 OCSP information. */
899 rc = tls_expand_session_files(server_sni, cbinfo);
900 if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
901
902 if (!init_dh(server_sni, cbinfo->dhparam, NULL))
903 return SSL_TLSEXT_ERR_NOACK;
904
905 DEBUG(D_tls) debug_printf("Switching SSL context.\n");
906 SSL_set_SSL_CTX(s, server_sni);
907
908 return SSL_TLSEXT_ERR_OK;
909 }
910 #endif /* EXIM_HAVE_OPENSSL_TLSEXT */
911
912
913
914
915 #ifndef DISABLE_OCSP
916
917 /*************************************************
918 * Callback to handle OCSP Stapling *
919 *************************************************/
920
921 /* Called when acting as server during the TLS session setup if the client
922 requests OCSP information with a Certificate Status Request.
923
924 Documentation via openssl s_server.c and the Apache patch from the OpenSSL
925 project.
926
927 */
928
929 static int
930 tls_server_stapling_cb(SSL *s, void *arg)
931 {
932 const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
933 uschar *response_der;
934 int response_der_len;
935
936 DEBUG(D_tls)
937 debug_printf("Received TLS status request (OCSP stapling); %s response.",
938 cbinfo->u_ocsp.server.response ? "have" : "lack");
939
940 tls_in.ocsp = OCSP_NOT_RESP;
941 if (!cbinfo->u_ocsp.server.response)
942 return SSL_TLSEXT_ERR_NOACK;
943
944 response_der = NULL;
945 response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response,
946 &response_der);
947 if (response_der_len <= 0)
948 return SSL_TLSEXT_ERR_NOACK;
949
950 SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len);
951 tls_in.ocsp = OCSP_VFIED;
952 return SSL_TLSEXT_ERR_OK;
953 }
954
955
956 static void
957 time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time)
958 {
959 BIO_printf(bp, "\t%s: ", str);
960 ASN1_GENERALIZEDTIME_print(bp, time);
961 BIO_puts(bp, "\n");
962 }
963
964 static int
965 tls_client_stapling_cb(SSL *s, void *arg)
966 {
967 tls_ext_ctx_cb * cbinfo = arg;
968 const unsigned char * p;
969 int len;
970 OCSP_RESPONSE * rsp;
971 OCSP_BASICRESP * bs;
972 int i;
973
974 DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):");
975 len = SSL_get_tlsext_status_ocsp_resp(s, &p);
976 if(!p)
977 {
978 /* Expect this when we requested ocsp but got none */
979 if ( cbinfo->u_ocsp.client.verify_required
980 && log_extra_selector & LX_tls_cipher)
981 log_write(0, LOG_MAIN, "Received TLS status callback, null content");
982 else
983 DEBUG(D_tls) debug_printf(" null\n");
984 return cbinfo->u_ocsp.client.verify_required ? 0 : 1;
985 }
986
987 if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
988 {
989 tls_out.ocsp = OCSP_FAILED;
990 if (log_extra_selector & LX_tls_cipher)
991 log_write(0, LOG_MAIN, "Received TLS cert status response, parse error");
992 else
993 DEBUG(D_tls) debug_printf(" parse error\n");
994 return 0;
995 }
996
997 if(!(bs = OCSP_response_get1_basic(rsp)))
998 {
999 tls_out.ocsp = OCSP_FAILED;
1000 if (log_extra_selector & LX_tls_cipher)
1001 log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response");
1002 else
1003 DEBUG(D_tls) debug_printf(" error parsing response\n");
1004 OCSP_RESPONSE_free(rsp);
1005 return 0;
1006 }
1007
1008 /* We'd check the nonce here if we'd put one in the request. */
1009 /* However that would defeat cacheability on the server so we don't. */
1010
1011 /* This section of code reworked from OpenSSL apps source;
1012 The OpenSSL Project retains copyright:
1013 Copyright (c) 1999 The OpenSSL Project. All rights reserved.
1014 */
1015 {
1016 BIO * bp = NULL;
1017 int status, reason;
1018 ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
1019
1020 DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE);
1021
1022 /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */
1023
1024 /* Use the chain that verified the server cert to verify the stapled info */
1025 /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */
1026
1027 if ((i = OCSP_basic_verify(bs, NULL,
1028 cbinfo->u_ocsp.client.verify_store, 0)) <= 0)
1029 {
1030 tls_out.ocsp = OCSP_FAILED;
1031 if (log_extra_selector & LX_tls_cipher)
1032 log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable");
1033 BIO_printf(bp, "OCSP response verify failure\n");
1034 ERR_print_errors(bp);
1035 i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
1036 goto out;
1037 }
1038
1039 BIO_printf(bp, "OCSP response well-formed and signed OK\n");
1040
1041 {
1042 STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses;
1043 OCSP_SINGLERESP * single;
1044
1045 if (sk_OCSP_SINGLERESP_num(sresp) != 1)
1046 {
1047 tls_out.ocsp = OCSP_FAILED;
1048 log_write(0, LOG_MAIN, "OCSP stapling "
1049 "with multiple responses not handled");
1050 i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
1051 goto out;
1052 }
1053 single = OCSP_resp_get0(bs, 0);
1054 status = OCSP_single_get0_status(single, &reason, &rev,
1055 &thisupd, &nextupd);
1056 }
1057
1058 DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd);
1059 DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd);
1060 if (!OCSP_check_validity(thisupd, nextupd,
1061 EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
1062 {
1063 tls_out.ocsp = OCSP_FAILED;
1064 DEBUG(D_tls) ERR_print_errors(bp);
1065 log_write(0, LOG_MAIN, "Server OSCP dates invalid");
1066 i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
1067 }
1068 else
1069 {
1070 DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n",
1071 OCSP_cert_status_str(status));
1072 switch(status)
1073 {
1074 case V_OCSP_CERTSTATUS_GOOD:
1075 tls_out.ocsp = OCSP_VFIED;
1076 i = 1;
1077 break;
1078 case V_OCSP_CERTSTATUS_REVOKED:
1079 tls_out.ocsp = OCSP_FAILED;
1080 log_write(0, LOG_MAIN, "Server certificate revoked%s%s",
1081 reason != -1 ? "; reason: " : "",
1082 reason != -1 ? OCSP_crl_reason_str(reason) : "");
1083 DEBUG(D_tls) time_print(bp, "Revocation Time", rev);
1084 i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
1085 break;
1086 default:
1087 tls_out.ocsp = OCSP_FAILED;
1088 log_write(0, LOG_MAIN,
1089 "Server certificate status unknown, in OCSP stapling");
1090 i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
1091 break;
1092 }
1093 }
1094 out:
1095 BIO_free(bp);
1096 }
1097
1098 OCSP_RESPONSE_free(rsp);
1099 return i;
1100 }
1101 #endif /*!DISABLE_OCSP*/
1102
1103
1104 /*************************************************
1105 * Initialize for TLS *
1106 *************************************************/
1107
1108 /* Called from both server and client code, to do preliminary initialization
1109 of the library. We allocate and return a context structure.
1110
1111 Arguments:
1112 ctxp returned SSL context
1113 host connected host, if client; NULL if server
1114 dhparam DH parameter file
1115 certificate certificate file
1116 privatekey private key
1117 ocsp_file file of stapling info (server); flag for require ocsp (client)
1118 addr address if client; NULL if server (for some randomness)
1119 cbp place to put allocated callback context
1120
1121 Returns: OK/DEFER/FAIL
1122 */
1123
1124 static int
1125 tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate,
1126 uschar *privatekey,
1127 #ifndef DISABLE_OCSP
1128 uschar *ocsp_file,
1129 #endif
1130 address_item *addr, tls_ext_ctx_cb ** cbp)
1131 {
1132 long init_options;
1133 int rc;
1134 BOOL okay;
1135 tls_ext_ctx_cb * cbinfo;
1136
1137 cbinfo = store_malloc(sizeof(tls_ext_ctx_cb));
1138 cbinfo->certificate = certificate;
1139 cbinfo->privatekey = privatekey;
1140 #ifndef DISABLE_OCSP
1141 if ((cbinfo->is_server = host==NULL))
1142 {
1143 cbinfo->u_ocsp.server.file = ocsp_file;
1144 cbinfo->u_ocsp.server.file_expanded = NULL;
1145 cbinfo->u_ocsp.server.response = NULL;
1146 }
1147 else
1148 cbinfo->u_ocsp.client.verify_store = NULL;
1149 #endif
1150 cbinfo->dhparam = dhparam;
1151 cbinfo->server_cipher_list = NULL;
1152 cbinfo->host = host;
1153 #ifdef EXPERIMENTAL_EVENT
1154 cbinfo->event_action = NULL;
1155 #endif
1156
1157 SSL_load_error_strings(); /* basic set up */
1158 OpenSSL_add_ssl_algorithms();
1159
1160 #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
1161 /* SHA256 is becoming ever more popular. This makes sure it gets added to the
1162 list of available digests. */
1163 EVP_add_digest(EVP_sha256());
1164 #endif
1165
1166 /* Create a context.
1167 The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant
1168 negotiation in the different methods; as far as I can tell, the only
1169 *_{server,client}_method which allows negotiation is SSLv23, which exists even
1170 when OpenSSL is built without SSLv2 support.
1171 By disabling with openssl_options, we can let admins re-enable with the
1172 existing knob. */
1173
1174 *ctxp = SSL_CTX_new((host == NULL)?
1175 SSLv23_server_method() : SSLv23_client_method());
1176
1177 if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL);
1178
1179 /* It turns out that we need to seed the random number generator this early in
1180 order to get the full complement of ciphers to work. It took me roughly a day
1181 of work to discover this by experiment.
1182
1183 On systems that have /dev/urandom, SSL may automatically seed itself from
1184 there. Otherwise, we have to make something up as best we can. Double check
1185 afterwards. */
1186
1187 if (!RAND_status())
1188 {
1189 randstuff r;
1190 gettimeofday(&r.tv, NULL);
1191 r.p = getpid();
1192
1193 RAND_seed((uschar *)(&r), sizeof(r));
1194 RAND_seed((uschar *)big_buffer, big_buffer_size);
1195 if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr));
1196
1197 if (!RAND_status())
1198 return tls_error(US"RAND_status", host,
1199 US"unable to seed random number generator");
1200 }
1201
1202 /* Set up the information callback, which outputs if debugging is at a suitable
1203 level. */
1204
1205 SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback);
1206
1207 /* Automatically re-try reads/writes after renegotiation. */
1208 (void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY);
1209
1210 /* Apply administrator-supplied work-arounds.
1211 Historically we applied just one requested option,
1212 SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we
1213 moved to an administrator-controlled list of options to specify and
1214 grandfathered in the first one as the default value for "openssl_options".
1215
1216 No OpenSSL version number checks: the options we accept depend upon the
1217 availability of the option value macros from OpenSSL. */
1218
1219 okay = tls_openssl_options_parse(openssl_options, &init_options);
1220 if (!okay)
1221 return tls_error(US"openssl_options parsing failed", host, NULL);
1222
1223 if (init_options)
1224 {
1225 DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options);
1226 if (!(SSL_CTX_set_options(*ctxp, init_options)))
1227 return tls_error(string_sprintf(
1228 "SSL_CTX_set_option(%#lx)", init_options), host, NULL);
1229 }
1230 else
1231 DEBUG(D_tls) debug_printf("no SSL CTX options to set\n");
1232
1233 /* Initialize with DH parameters if supplied */
1234
1235 if (!init_dh(*ctxp, dhparam, host)) return DEFER;
1236
1237 /* Set up certificate and key (and perhaps OCSP info) */
1238
1239 rc = tls_expand_session_files(*ctxp, cbinfo);
1240 if (rc != OK) return rc;
1241
1242 /* If we need to handle SNI, do so */
1243 #ifdef EXIM_HAVE_OPENSSL_TLSEXT
1244 if (host == NULL) /* server */
1245 {
1246 # ifndef DISABLE_OCSP
1247 /* We check u_ocsp.server.file, not server.response, because we care about if
1248 the option exists, not what the current expansion might be, as SNI might
1249 change the certificate and OCSP file in use between now and the time the
1250 callback is invoked. */
1251 if (cbinfo->u_ocsp.server.file)
1252 {
1253 SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb);
1254 SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo);
1255 }
1256 # endif
1257 /* We always do this, so that $tls_sni is available even if not used in
1258 tls_certificate */
1259 SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb);
1260 SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo);
1261 }
1262 # ifndef DISABLE_OCSP
1263 else /* client */
1264 if(ocsp_file) /* wanting stapling */
1265 {
1266 if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new()))
1267 {
1268 DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n");
1269 return FAIL;
1270 }
1271 SSL_CTX_set_tlsext_status_cb(*ctxp, tls_client_stapling_cb);
1272 SSL_CTX_set_tlsext_status_arg(*ctxp, cbinfo);
1273 }
1274 # endif
1275 #endif
1276
1277 #ifdef EXPERIMENTAL_CERTNAMES
1278 cbinfo->verify_cert_hostnames = NULL;
1279 #endif
1280
1281 /* Set up the RSA callback */
1282
1283 SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback);
1284
1285 /* Finally, set the timeout, and we are done */
1286
1287 SSL_CTX_set_timeout(*ctxp, ssl_session_timeout);
1288 DEBUG(D_tls) debug_printf("Initialized TLS\n");
1289
1290 *cbp = cbinfo;
1291
1292 return OK;
1293 }
1294
1295
1296
1297
1298 /*************************************************
1299 * Get name of cipher in use *
1300 *************************************************/
1301
1302 /*
1303 Argument: pointer to an SSL structure for the connection
1304 buffer to use for answer
1305 size of buffer
1306 pointer to number of bits for cipher
1307 Returns: nothing
1308 */
1309
1310 static void
1311 construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits)
1312 {
1313 /* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't
1314 yet reflect that. It should be a safe change anyway, even 0.9.8 versions have
1315 the accessor functions use const in the prototype. */
1316 const SSL_CIPHER *c;
1317 const uschar *ver;
1318
1319 ver = (const uschar *)SSL_get_version(ssl);
1320
1321 c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl);
1322 SSL_CIPHER_get_bits(c, bits);
1323
1324 string_format(cipherbuf, bsize, "%s:%s:%u", ver,
1325 SSL_CIPHER_get_name(c), *bits);
1326
1327 DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf);
1328 }
1329
1330
1331
1332
1333
1334 /*************************************************
1335 * Set up for verifying certificates *
1336 *************************************************/
1337
1338 /* Called by both client and server startup
1339
1340 Arguments:
1341 sctx SSL_CTX* to initialise
1342 certs certs file or NULL
1343 crl CRL file or NULL
1344 host NULL in a server; the remote host in a client
1345 optional TRUE if called from a server for a host in tls_try_verify_hosts;
1346 otherwise passed as FALSE
1347 cert_vfy_cb Callback function for certificate verification
1348
1349 Returns: OK/DEFER/FAIL
1350 */
1351
1352 static int
1353 setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
1354 int (*cert_vfy_cb)(int, X509_STORE_CTX *) )
1355 {
1356 uschar *expcerts, *expcrl;
1357
1358 if (!expand_check(certs, US"tls_verify_certificates", &expcerts))
1359 return DEFER;
1360
1361 if (expcerts != NULL && *expcerts != '\0')
1362 {
1363 struct stat statbuf;
1364 if (!SSL_CTX_set_default_verify_paths(sctx))
1365 return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL);
1366
1367 if (Ustat(expcerts, &statbuf) < 0)
1368 {
1369 log_write(0, LOG_MAIN|LOG_PANIC,
1370 "failed to stat %s for certificates", expcerts);
1371 return DEFER;
1372 }
1373 else
1374 {
1375 uschar *file, *dir;
1376 if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
1377 { file = NULL; dir = expcerts; }
1378 else
1379 { file = expcerts; dir = NULL; }
1380
1381 /* If a certificate file is empty, the next function fails with an
1382 unhelpful error message. If we skip it, we get the correct behaviour (no
1383 certificates are recognized, but the error message is still misleading (it
1384 says no certificate was supplied.) But this is better. */
1385
1386 if ((file == NULL || statbuf.st_size > 0) &&
1387 !SSL_CTX_load_verify_locations(sctx, CS file, CS dir))
1388 return tls_error(US"SSL_CTX_load_verify_locations", host, NULL);
1389
1390 /* Load the list of CAs for which we will accept certs, for sending
1391 to the client. This is only for the one-file tls_verify_certificates
1392 variant.
1393 If a list isn't loaded into the server, but
1394 some verify locations are set, the server end appears to make
1395 a wildcard reqest for client certs.
1396 Meanwhile, the client library as deafult behaviour *ignores* the list
1397 we send over the wire - see man SSL_CTX_set_client_cert_cb.
1398 Because of this, and that the dir variant is likely only used for
1399 the public-CA bundle (not for a private CA), not worth fixing.
1400 */
1401 if (file != NULL)
1402 {
1403 STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file);
1404 DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n",
1405 sk_X509_NAME_num(names));
1406 SSL_CTX_set_client_CA_list(sctx, names);
1407 }
1408 }
1409
1410 /* Handle a certificate revocation list. */
1411
1412 #if OPENSSL_VERSION_NUMBER > 0x00907000L
1413
1414 /* This bit of code is now the version supplied by Lars Mainka. (I have
1415 * merely reformatted it into the Exim code style.)
1416
1417 * "From here I changed the code to add support for multiple crl's
1418 * in pem format in one file or to support hashed directory entries in
1419 * pem format instead of a file. This method now uses the library function
1420 * X509_STORE_load_locations to add the CRL location to the SSL context.
1421 * OpenSSL will then handle the verify against CA certs and CRLs by
1422 * itself in the verify callback." */
1423
1424 if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER;
1425 if (expcrl != NULL && *expcrl != 0)
1426 {
1427 struct stat statbufcrl;
1428 if (Ustat(expcrl, &statbufcrl) < 0)
1429 {
1430 log_write(0, LOG_MAIN|LOG_PANIC,
1431 "failed to stat %s for certificates revocation lists", expcrl);
1432 return DEFER;
1433 }
1434 else
1435 {
1436 /* is it a file or directory? */
1437 uschar *file, *dir;
1438 X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx);
1439 if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR)
1440 {
1441 file = NULL;
1442 dir = expcrl;
1443 DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir);
1444 }
1445 else
1446 {
1447 file = expcrl;
1448 dir = NULL;
1449 DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file);
1450 }
1451 if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0)
1452 return tls_error(US"X509_STORE_load_locations", host, NULL);
1453
1454 /* setting the flags to check against the complete crl chain */
1455
1456 X509_STORE_set_flags(cvstore,
1457 X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL);
1458 }
1459 }
1460
1461 #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
1462
1463 /* If verification is optional, don't fail if no certificate */
1464
1465 SSL_CTX_set_verify(sctx,
1466 SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT),
1467 cert_vfy_cb);
1468 }
1469
1470 return OK;
1471 }
1472
1473
1474
1475 /*************************************************
1476 * Start a TLS session in a server *
1477 *************************************************/
1478
1479 /* This is called when Exim is running as a server, after having received
1480 the STARTTLS command. It must respond to that command, and then negotiate
1481 a TLS session.
1482
1483 Arguments:
1484 require_ciphers allowed ciphers
1485
1486 Returns: OK on success
1487 DEFER for errors before the start of the negotiation
1488 FAIL for errors during the negotation; the server can't
1489 continue running.
1490 */
1491
1492 int
1493 tls_server_start(const uschar *require_ciphers)
1494 {
1495 int rc;
1496 uschar *expciphers;
1497 tls_ext_ctx_cb *cbinfo;
1498 static uschar cipherbuf[256];
1499
1500 /* Check for previous activation */
1501
1502 if (tls_in.active >= 0)
1503 {
1504 tls_error(US"STARTTLS received after TLS started", NULL, US"");
1505 smtp_printf("554 Already in TLS\r\n");
1506 return FAIL;
1507 }
1508
1509 /* Initialize the SSL library. If it fails, it will already have logged
1510 the error. */
1511
1512 rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey,
1513 #ifndef DISABLE_OCSP
1514 tls_ocsp_file,
1515 #endif
1516 NULL, &server_static_cbinfo);
1517 if (rc != OK) return rc;
1518 cbinfo = server_static_cbinfo;
1519
1520 if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers))
1521 return FAIL;
1522
1523 /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
1524 were historically separated by underscores. So that I can use either form in my
1525 tests, and also for general convenience, we turn underscores into hyphens here.
1526 */
1527
1528 if (expciphers != NULL)
1529 {
1530 uschar *s = expciphers;
1531 while (*s != 0) { if (*s == '_') *s = '-'; s++; }
1532 DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers);
1533 if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers))
1534 return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL);
1535 cbinfo->server_cipher_list = expciphers;
1536 }
1537
1538 /* If this is a host for which certificate verification is mandatory or
1539 optional, set up appropriately. */
1540
1541 tls_in.certificate_verified = FALSE;
1542 #ifdef EXPERIMENTAL_DANE
1543 tls_in.dane_verified = FALSE;
1544 #endif
1545 server_verify_callback_called = FALSE;
1546
1547 if (verify_check_host(&tls_verify_hosts) == OK)
1548 {
1549 rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL,
1550 FALSE, verify_callback_server);
1551 if (rc != OK) return rc;
1552 server_verify_optional = FALSE;
1553 }
1554 else if (verify_check_host(&tls_try_verify_hosts) == OK)
1555 {
1556 rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL,
1557 TRUE, verify_callback_server);
1558 if (rc != OK) return rc;
1559 server_verify_optional = TRUE;
1560 }
1561
1562 /* Prepare for new connection */
1563
1564 if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL);
1565
1566 /* Warning: we used to SSL_clear(ssl) here, it was removed.
1567 *
1568 * With the SSL_clear(), we get strange interoperability bugs with
1569 * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in
1570 * OpenSSL itself, as a clear should not lead to inability to follow protocols.
1571 *
1572 * The SSL_clear() call is to let an existing SSL* be reused, typically after
1573 * session shutdown. In this case, we have a brand new object and there's no
1574 * obvious reason to immediately clear it. I'm guessing that this was
1575 * originally added because of incomplete initialisation which the clear fixed,
1576 * in some historic release.
1577 */
1578
1579 /* Set context and tell client to go ahead, except in the case of TLS startup
1580 on connection, where outputting anything now upsets the clients and tends to
1581 make them disconnect. We need to have an explicit fflush() here, to force out
1582 the response. Other smtp_printf() calls do not need it, because in non-TLS
1583 mode, the fflush() happens when smtp_getc() is called. */
1584
1585 SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx));
1586 if (!tls_in.on_connect)
1587 {
1588 smtp_printf("220 TLS go ahead\r\n");
1589 fflush(smtp_out);
1590 }
1591
1592 /* Now negotiate the TLS session. We put our own timer on it, since it seems
1593 that the OpenSSL library doesn't. */
1594
1595 SSL_set_wfd(server_ssl, fileno(smtp_out));
1596 SSL_set_rfd(server_ssl, fileno(smtp_in));
1597 SSL_set_accept_state(server_ssl);
1598
1599 DEBUG(D_tls) debug_printf("Calling SSL_accept\n");
1600
1601 sigalrm_seen = FALSE;
1602 if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
1603 rc = SSL_accept(server_ssl);
1604 alarm(0);
1605
1606 if (rc <= 0)
1607 {
1608 tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL);
1609 if (ERR_get_error() == 0)
1610 log_write(0, LOG_MAIN,
1611 "TLS client disconnected cleanly (rejected our certificate?)");
1612 return FAIL;
1613 }
1614
1615 DEBUG(D_tls) debug_printf("SSL_accept was successful\n");
1616
1617 /* TLS has been set up. Adjust the input functions to read via TLS,
1618 and initialize things. */
1619
1620 construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits);
1621 tls_in.cipher = cipherbuf;
1622
1623 DEBUG(D_tls)
1624 {
1625 uschar buf[2048];
1626 if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL)
1627 debug_printf("Shared ciphers: %s\n", buf);
1628 }
1629
1630 /* Record the certificate we presented */
1631 {
1632 X509 * crt = SSL_get_certificate(server_ssl);
1633 tls_in.ourcert = crt ? X509_dup(crt) : NULL;
1634 }
1635
1636 /* Only used by the server-side tls (tls_in), including tls_getc.
1637 Client-side (tls_out) reads (seem to?) go via
1638 smtp_read_response()/ip_recv().
1639 Hence no need to duplicate for _in and _out.
1640 */
1641 ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size);
1642 ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0;
1643 ssl_xfer_eof = ssl_xfer_error = 0;
1644
1645 receive_getc = tls_getc;
1646 receive_ungetc = tls_ungetc;
1647 receive_feof = tls_feof;
1648 receive_ferror = tls_ferror;
1649 receive_smtp_buffered = tls_smtp_buffered;
1650
1651 tls_in.active = fileno(smtp_out);
1652 return OK;
1653 }
1654
1655
1656
1657
1658 static int
1659 tls_client_basic_ctx_init(SSL_CTX * ctx,
1660 host_item * host, smtp_transport_options_block * ob
1661 #ifdef EXPERIMENTAL_CERTNAMES
1662 , tls_ext_ctx_cb * cbinfo
1663 #endif
1664 )
1665 {
1666 int rc;
1667 /* stick to the old behaviour for compatibility if tls_verify_certificates is
1668 set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only
1669 the specified host patterns if one of them is defined */
1670
1671 if ((!ob->tls_verify_hosts && !ob->tls_try_verify_hosts) ||
1672 (verify_check_host(&ob->tls_verify_hosts) == OK))
1673 {
1674 if ((rc = setup_certs(ctx, ob->tls_verify_certificates,
1675 ob->tls_crl, host, FALSE, verify_callback_client)) != OK)
1676 return rc;
1677 client_verify_optional = FALSE;
1678
1679 #ifdef EXPERIMENTAL_CERTNAMES
1680 if (ob->tls_verify_cert_hostnames)
1681 {
1682 if (!expand_check(ob->tls_verify_cert_hostnames,
1683 US"tls_verify_cert_hostnames",
1684 &cbinfo->verify_cert_hostnames))
1685 return FAIL;
1686 if (cbinfo->verify_cert_hostnames)
1687 DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n",
1688 cbinfo->verify_cert_hostnames);
1689 }
1690 #endif
1691 }
1692 else if (verify_check_host(&ob->tls_try_verify_hosts) == OK)
1693 {
1694 if ((rc = setup_certs(ctx, ob->tls_verify_certificates,
1695 ob->tls_crl, host, TRUE, verify_callback_client)) != OK)
1696 return rc;
1697 client_verify_optional = TRUE;
1698 }
1699
1700 return OK;
1701 }
1702
1703
1704 #ifdef EXPERIMENTAL_DANE
1705 static int
1706 dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa)
1707 {
1708 dns_record * rr;
1709 dns_scan dnss;
1710 const char * hostnames[2] = { CS host->name, NULL };
1711 int found = 0;
1712
1713 if (DANESSL_init(ssl, NULL, hostnames) != 1)
1714 return tls_error(US"hostnames load", host, NULL);
1715
1716 for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
1717 rr;
1718 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
1719 ) if (rr->type == T_TLSA)
1720 {
1721 uschar * p = rr->data;
1722 uint8_t usage, selector, mtype;
1723 const char * mdname;
1724
1725 usage = *p++;
1726
1727 /* Only DANE-TA(2) and DANE-EE(3) are supported */
1728 if (usage != 2 && usage != 3) continue;
1729
1730 selector = *p++;
1731 mtype = *p++;
1732
1733 switch (mtype)
1734 {
1735 default: continue; /* Only match-types 0, 1, 2 are supported */
1736 case 0: mdname = NULL; break;
1737 case 1: mdname = "sha256"; break;
1738 case 2: mdname = "sha512"; break;
1739 }
1740
1741 found++;
1742 switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3))
1743 {
1744 default:
1745 case 0: /* action not taken */
1746 return tls_error(US"tlsa load", host, NULL);
1747 case 1: break;
1748 }
1749
1750 tls_out.tlsa_usage |= 1<<usage;
1751 }
1752
1753 if (found)
1754 return OK;
1755
1756 log_write(0, LOG_MAIN, "DANE error: No usable TLSA records");
1757 return FAIL;
1758 }
1759 #endif /*EXPERIMENTAL_DANE*/
1760
1761
1762
1763 /*************************************************
1764 * Start a TLS session in a client *
1765 *************************************************/
1766
1767 /* Called from the smtp transport after STARTTLS has been accepted.
1768
1769 Argument:
1770 fd the fd of the connection
1771 host connected host (for messages)
1772 addr the first address
1773 tb transport (always smtp)
1774 tlsa_dnsa tlsa lookup, if DANE, else null
1775
1776 Returns: OK on success
1777 FAIL otherwise - note that tls_error() will not give DEFER
1778 because this is not a server
1779 */
1780
1781 int
1782 tls_client_start(int fd, host_item *host, address_item *addr,
1783 transport_instance *tb
1784 #ifdef EXPERIMENTAL_DANE
1785 , dns_answer * tlsa_dnsa
1786 #endif
1787 )
1788 {
1789 smtp_transport_options_block * ob =
1790 (smtp_transport_options_block *)tb->options_block;
1791 static uschar txt[256];
1792 uschar * expciphers;
1793 X509 * server_cert;
1794 int rc;
1795 static uschar cipherbuf[256];
1796
1797 #ifndef DISABLE_OCSP
1798 BOOL request_ocsp = FALSE;
1799 BOOL require_ocsp = FALSE;
1800 #endif
1801
1802 #ifdef EXPERIMENTAL_DANE
1803 tls_out.tlsa_usage = 0;
1804 #endif
1805
1806 #ifndef DISABLE_OCSP
1807 {
1808 # ifdef EXPERIMENTAL_DANE
1809 if ( tlsa_dnsa
1810 && ob->hosts_request_ocsp[0] == '*'
1811 && ob->hosts_request_ocsp[1] == '\0'
1812 )
1813 {
1814 /* Unchanged from default. Use a safer one under DANE */
1815 request_ocsp = TRUE;
1816 ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} "
1817 " {= {4}{$tls_out_tlsa_usage}} } "
1818 " {*}{}}";
1819 }
1820 # endif
1821
1822 if ((require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp,
1823 NULL, host->name, host->address, NULL) == OK))
1824 request_ocsp = TRUE;
1825 else
1826 # ifdef EXPERIMENTAL_DANE
1827 if (!request_ocsp)
1828 # endif
1829 request_ocsp = verify_check_this_host(&ob->hosts_request_ocsp,
1830 NULL, host->name, host->address, NULL) == OK;
1831 }
1832 #endif
1833
1834 rc = tls_init(&client_ctx, host, NULL,
1835 ob->tls_certificate, ob->tls_privatekey,
1836 #ifndef DISABLE_OCSP
1837 (void *)(long)request_ocsp,
1838 #endif
1839 addr, &client_static_cbinfo);
1840 if (rc != OK) return rc;
1841
1842 tls_out.certificate_verified = FALSE;
1843 client_verify_callback_called = FALSE;
1844
1845 if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers",
1846 &expciphers))
1847 return FAIL;
1848
1849 /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
1850 are separated by underscores. So that I can use either form in my tests, and
1851 also for general convenience, we turn underscores into hyphens here. */
1852
1853 if (expciphers != NULL)
1854 {
1855 uschar *s = expciphers;
1856 while (*s != 0) { if (*s == '_') *s = '-'; s++; }
1857 DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers);
1858 if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers))
1859 return tls_error(US"SSL_CTX_set_cipher_list", host, NULL);
1860 }
1861
1862 #ifdef EXPERIMENTAL_DANE
1863 if (tlsa_dnsa)
1864 {
1865 SSL_CTX_set_verify(client_ctx, SSL_VERIFY_PEER, verify_callback_client_dane);
1866
1867 if (!DANESSL_library_init())
1868 return tls_error(US"library init", host, NULL);
1869 if (DANESSL_CTX_init(client_ctx) <= 0)
1870 return tls_error(US"context init", host, NULL);
1871 }
1872 else
1873
1874 #endif
1875
1876 if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob
1877 #ifdef EXPERIMENTAL_CERTNAMES
1878 , client_static_cbinfo
1879 #endif
1880 )) != OK)
1881 return rc;
1882
1883 if ((client_ssl = SSL_new(client_ctx)) == NULL)
1884 return tls_error(US"SSL_new", host, NULL);
1885 SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx));
1886 SSL_set_fd(client_ssl, fd);
1887 SSL_set_connect_state(client_ssl);
1888
1889 if (ob->tls_sni)
1890 {
1891 if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni))
1892 return FAIL;
1893 if (tls_out.sni == NULL)
1894 {
1895 DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n");
1896 }
1897 else if (!Ustrlen(tls_out.sni))
1898 tls_out.sni = NULL;
1899 else
1900 {
1901 #ifdef EXIM_HAVE_OPENSSL_TLSEXT
1902 DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni);
1903 SSL_set_tlsext_host_name(client_ssl, tls_out.sni);
1904 #else
1905 DEBUG(D_tls)
1906 debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n",
1907 tls_out.sni);
1908 #endif
1909 }
1910 }
1911
1912 #ifdef EXPERIMENTAL_DANE
1913 if (tlsa_dnsa)
1914 if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa)) != OK)
1915 return rc;
1916 #endif
1917
1918 #ifndef DISABLE_OCSP
1919 /* Request certificate status at connection-time. If the server
1920 does OCSP stapling we will get the callback (set in tls_init()) */
1921 # ifdef EXPERIMENTAL_DANE
1922 if (request_ocsp)
1923 {
1924 const uschar * s;
1925 if ( ((s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage"))
1926 || ((s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage"))
1927 )
1928 { /* Re-eval now $tls_out_tlsa_usage is populated. If
1929 this means we avoid the OCSP request, we wasted the setup
1930 cost in tls_init(). */
1931 require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp,
1932 NULL, host->name, host->address, NULL) == OK;
1933 request_ocsp = require_ocsp ? TRUE
1934 : verify_check_this_host(&ob->hosts_request_ocsp,
1935 NULL, host->name, host->address, NULL) == OK;
1936 }
1937 }
1938 # endif
1939
1940 if (request_ocsp)
1941 {
1942 SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp);
1943 client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp;
1944 tls_out.ocsp = OCSP_NOT_RESP;
1945 }
1946 #endif
1947
1948 #ifdef EXPERIMENTAL_EVENT
1949 client_static_cbinfo->event_action = tb->event_action;
1950 #endif
1951
1952 /* There doesn't seem to be a built-in timeout on connection. */
1953
1954 DEBUG(D_tls) debug_printf("Calling SSL_connect\n");
1955 sigalrm_seen = FALSE;
1956 alarm(ob->command_timeout);
1957 rc = SSL_connect(client_ssl);
1958 alarm(0);
1959
1960 #ifdef EXPERIMENTAL_DANE
1961 if (tlsa_dnsa)
1962 DANESSL_cleanup(client_ssl);
1963 #endif
1964
1965 if (rc <= 0)
1966 return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL);
1967
1968 DEBUG(D_tls) debug_printf("SSL_connect succeeded\n");
1969
1970 /* Beware anonymous ciphers which lead to server_cert being NULL */
1971 /*XXX server_cert is never freed... use X509_free() */
1972 server_cert = SSL_get_peer_certificate (client_ssl);
1973 if (server_cert)
1974 {
1975 tls_out.peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert),
1976 CS txt, sizeof(txt));
1977 tls_out.peerdn = txt; /*XXX a static buffer... */
1978 }
1979 else
1980 tls_out.peerdn = NULL;
1981
1982 construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits);
1983 tls_out.cipher = cipherbuf;
1984
1985 /* Record the certificate we presented */
1986 {
1987 X509 * crt = SSL_get_certificate(client_ssl);
1988 tls_out.ourcert = crt ? X509_dup(crt) : NULL;
1989 }
1990
1991 tls_out.active = fd;
1992 return OK;
1993 }
1994
1995
1996
1997
1998
1999 /*************************************************
2000 * TLS version of getc *
2001 *************************************************/
2002
2003 /* This gets the next byte from the TLS input buffer. If the buffer is empty,
2004 it refills the buffer via the SSL reading function.
2005
2006 Arguments: none
2007 Returns: the next character or EOF
2008
2009 Only used by the server-side TLS.
2010 */
2011
2012 int
2013 tls_getc(void)
2014 {
2015 if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm)
2016 {
2017 int error;
2018 int inbytes;
2019
2020 DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl,
2021 ssl_xfer_buffer, ssl_xfer_buffer_size);
2022
2023 if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
2024 inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size);
2025 error = SSL_get_error(server_ssl, inbytes);
2026 alarm(0);
2027
2028 /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been
2029 closed down, not that the socket itself has been closed down. Revert to
2030 non-SSL handling. */
2031
2032 if (error == SSL_ERROR_ZERO_RETURN)
2033 {
2034 DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
2035
2036 receive_getc = smtp_getc;
2037 receive_ungetc = smtp_ungetc;
2038 receive_feof = smtp_feof;
2039 receive_ferror = smtp_ferror;
2040 receive_smtp_buffered = smtp_buffered;
2041
2042 SSL_free(server_ssl);
2043 server_ssl = NULL;
2044 tls_in.active = -1;
2045 tls_in.bits = 0;
2046 tls_in.cipher = NULL;
2047 tls_in.peerdn = NULL;
2048 tls_in.sni = NULL;
2049
2050 return smtp_getc();
2051 }
2052
2053 /* Handle genuine errors */
2054
2055 else if (error == SSL_ERROR_SSL)
2056 {
2057 ERR_error_string(ERR_get_error(), ssl_errstring);
2058 log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring);
2059 ssl_xfer_error = 1;
2060 return EOF;
2061 }
2062
2063 else if (error != SSL_ERROR_NONE)
2064 {
2065 DEBUG(D_tls) debug_printf("Got SSL error %d\n", error);
2066 ssl_xfer_error = 1;
2067 return EOF;
2068 }
2069
2070 #ifndef DISABLE_DKIM
2071 dkim_exim_verify_feed(ssl_xfer_buffer, inbytes);
2072 #endif
2073 ssl_xfer_buffer_hwm = inbytes;
2074 ssl_xfer_buffer_lwm = 0;
2075 }
2076
2077 /* Something in the buffer; return next uschar */
2078
2079 return ssl_xfer_buffer[ssl_xfer_buffer_lwm++];
2080 }
2081
2082
2083
2084 /*************************************************
2085 * Read bytes from TLS channel *
2086 *************************************************/
2087
2088 /*
2089 Arguments:
2090 buff buffer of data
2091 len size of buffer
2092
2093 Returns: the number of bytes read
2094 -1 after a failed read
2095
2096 Only used by the client-side TLS.
2097 */
2098
2099 int
2100 tls_read(BOOL is_server, uschar *buff, size_t len)
2101 {
2102 SSL *ssl = is_server ? server_ssl : client_ssl;
2103 int inbytes;
2104 int error;
2105
2106 DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl,
2107 buff, (unsigned int)len);
2108
2109 inbytes = SSL_read(ssl, CS buff, len);
2110 error = SSL_get_error(ssl, inbytes);
2111
2112 if (error == SSL_ERROR_ZERO_RETURN)
2113 {
2114 DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
2115 return -1;
2116 }
2117 else if (error != SSL_ERROR_NONE)
2118 {
2119 return -1;
2120 }
2121
2122 return inbytes;
2123 }
2124
2125
2126
2127
2128
2129 /*************************************************
2130 * Write bytes down TLS channel *
2131 *************************************************/
2132
2133 /*
2134 Arguments:
2135 is_server channel specifier
2136 buff buffer of data
2137 len number of bytes
2138
2139 Returns: the number of bytes after a successful write,
2140 -1 after a failed write
2141
2142 Used by both server-side and client-side TLS.
2143 */
2144
2145 int
2146 tls_write(BOOL is_server, const uschar *buff, size_t len)
2147 {
2148 int outbytes;
2149 int error;
2150 int left = len;
2151 SSL *ssl = is_server ? server_ssl : client_ssl;
2152
2153 DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left);
2154 while (left > 0)
2155 {
2156 DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left);
2157 outbytes = SSL_write(ssl, CS buff, left);
2158 error = SSL_get_error(ssl, outbytes);
2159 DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error);
2160 switch (error)
2161 {
2162 case SSL_ERROR_SSL:
2163 ERR_error_string(ERR_get_error(), ssl_errstring);
2164 log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring);
2165 return -1;
2166
2167 case SSL_ERROR_NONE:
2168 left -= outbytes;
2169 buff += outbytes;
2170 break;
2171
2172 case SSL_ERROR_ZERO_RETURN:
2173 log_write(0, LOG_MAIN, "SSL channel closed on write");
2174 return -1;
2175
2176 case SSL_ERROR_SYSCALL:
2177 log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s",
2178 sender_fullhost ? sender_fullhost : US"<unknown>",
2179 strerror(errno));
2180
2181 default:
2182 log_write(0, LOG_MAIN, "SSL_write error %d", error);
2183 return -1;
2184 }
2185 }
2186 return len;
2187 }
2188
2189
2190
2191 /*************************************************
2192 * Close down a TLS session *
2193 *************************************************/
2194
2195 /* This is also called from within a delivery subprocess forked from the
2196 daemon, to shut down the TLS library, without actually doing a shutdown (which
2197 would tamper with the SSL session in the parent process).
2198
2199 Arguments: TRUE if SSL_shutdown is to be called
2200 Returns: nothing
2201
2202 Used by both server-side and client-side TLS.
2203 */
2204
2205 void
2206 tls_close(BOOL is_server, BOOL shutdown)
2207 {
2208 SSL **sslp = is_server ? &server_ssl : &client_ssl;
2209 int *fdp = is_server ? &tls_in.active : &tls_out.active;
2210
2211 if (*fdp < 0) return; /* TLS was not active */
2212
2213 if (shutdown)
2214 {
2215 DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n");
2216 SSL_shutdown(*sslp);
2217 }
2218
2219 SSL_free(*sslp);
2220 *sslp = NULL;
2221
2222 *fdp = -1;
2223 }
2224
2225
2226
2227
2228 /*************************************************
2229 * Let tls_require_ciphers be checked at startup *
2230 *************************************************/
2231
2232 /* The tls_require_ciphers option, if set, must be something which the
2233 library can parse.
2234
2235 Returns: NULL on success, or error message
2236 */
2237
2238 uschar *
2239 tls_validate_require_cipher(void)
2240 {
2241 SSL_CTX *ctx;
2242 uschar *s, *expciphers, *err;
2243
2244 /* this duplicates from tls_init(), we need a better "init just global
2245 state, for no specific purpose" singleton function of our own */
2246
2247 SSL_load_error_strings();
2248 OpenSSL_add_ssl_algorithms();
2249 #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
2250 /* SHA256 is becoming ever more popular. This makes sure it gets added to the
2251 list of available digests. */
2252 EVP_add_digest(EVP_sha256());
2253 #endif
2254
2255 if (!(tls_require_ciphers && *tls_require_ciphers))
2256 return NULL;
2257
2258 if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers))
2259 return US"failed to expand tls_require_ciphers";
2260
2261 if (!(expciphers && *expciphers))
2262 return NULL;
2263
2264 /* normalisation ripped from above */
2265 s = expciphers;
2266 while (*s != 0) { if (*s == '_') *s = '-'; s++; }
2267
2268 err = NULL;
2269
2270 ctx = SSL_CTX_new(SSLv23_server_method());
2271 if (!ctx)
2272 {
2273 ERR_error_string(ERR_get_error(), ssl_errstring);
2274 return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring);
2275 }
2276
2277 DEBUG(D_tls)
2278 debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers);
2279
2280 if (!SSL_CTX_set_cipher_list(ctx, CS expciphers))
2281 {
2282 ERR_error_string(ERR_get_error(), ssl_errstring);
2283 err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers);
2284 }
2285
2286 SSL_CTX_free(ctx);
2287
2288 return err;
2289 }
2290
2291
2292
2293
2294 /*************************************************
2295 * Report the library versions. *
2296 *************************************************/
2297
2298 /* There have historically been some issues with binary compatibility in
2299 OpenSSL libraries; if Exim (like many other applications) is built against
2300 one version of OpenSSL but the run-time linker picks up another version,
2301 it can result in serious failures, including crashing with a SIGSEGV. So
2302 report the version found by the compiler and the run-time version.
2303
2304 Note: some OS vendors backport security fixes without changing the version
2305 number/string, and the version date remains unchanged. The _build_ date
2306 will change, so we can more usefully assist with version diagnosis by also
2307 reporting the build date.
2308
2309 Arguments: a FILE* to print the results to
2310 Returns: nothing
2311 */
2312
2313 void
2314 tls_version_report(FILE *f)
2315 {
2316 fprintf(f, "Library version: OpenSSL: Compile: %s\n"
2317 " Runtime: %s\n"
2318 " : %s\n",
2319 OPENSSL_VERSION_TEXT,
2320 SSLeay_version(SSLEAY_VERSION),
2321 SSLeay_version(SSLEAY_BUILT_ON));
2322 /* third line is 38 characters for the %s and the line is 73 chars long;
2323 the OpenSSL output includes a "built on: " prefix already. */
2324 }
2325
2326
2327
2328
2329 /*************************************************
2330 * Random number generation *
2331 *************************************************/
2332
2333 /* Pseudo-random number generation. The result is not expected to be
2334 cryptographically strong but not so weak that someone will shoot themselves
2335 in the foot using it as a nonce in input in some email header scheme or
2336 whatever weirdness they'll twist this into. The result should handle fork()
2337 and avoid repeating sequences. OpenSSL handles that for us.
2338
2339 Arguments:
2340 max range maximum
2341 Returns a random number in range [0, max-1]
2342 */
2343
2344 int
2345 vaguely_random_number(int max)
2346 {
2347 unsigned int r;
2348 int i, needed_len;
2349 static pid_t pidlast = 0;
2350 pid_t pidnow;
2351 uschar *p;
2352 uschar smallbuf[sizeof(r)];
2353
2354 if (max <= 1)
2355 return 0;
2356
2357 pidnow = getpid();
2358 if (pidnow != pidlast)
2359 {
2360 /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state
2361 is unique for each thread", this doesn't apparently apply across processes,
2362 so our own warning from vaguely_random_number_fallback() applies here too.
2363 Fix per PostgreSQL. */
2364 if (pidlast != 0)
2365 RAND_cleanup();
2366 pidlast = pidnow;
2367 }
2368
2369 /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */
2370 if (!RAND_status())
2371 {
2372 randstuff r;
2373 gettimeofday(&r.tv, NULL);
2374 r.p = getpid();
2375
2376 RAND_seed((uschar *)(&r), sizeof(r));
2377 }
2378 /* We're after pseudo-random, not random; if we still don't have enough data
2379 in the internal PRNG then our options are limited. We could sleep and hope
2380 for entropy to come along (prayer technique) but if the system is so depleted
2381 in the first place then something is likely to just keep taking it. Instead,
2382 we'll just take whatever little bit of pseudo-random we can still manage to
2383 get. */
2384
2385 needed_len = sizeof(r);
2386 /* Don't take 8 times more entropy than needed if int is 8 octets and we were
2387 asked for a number less than 10. */
2388 for (r = max, i = 0; r; ++i)
2389 r >>= 1;
2390 i = (i + 7) / 8;
2391 if (i < needed_len)
2392 needed_len = i;
2393
2394 /* We do not care if crypto-strong */
2395 i = RAND_pseudo_bytes(smallbuf, needed_len);
2396 if (i < 0)
2397 {
2398 DEBUG(D_all)
2399 debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n");
2400 return vaguely_random_number_fallback(max);
2401 }
2402
2403 r = 0;
2404 for (p = smallbuf; needed_len; --needed_len, ++p)
2405 {
2406 r *= 256;
2407 r += *p;
2408 }
2409
2410 /* We don't particularly care about weighted results; if someone wants
2411 smooth distribution and cares enough then they should submit a patch then. */
2412 return r % max;
2413 }
2414
2415
2416
2417
2418 /*************************************************
2419 * OpenSSL option parse *
2420 *************************************************/
2421
2422 /* Parse one option for tls_openssl_options_parse below
2423
2424 Arguments:
2425 name one option name
2426 value place to store a value for it
2427 Returns success or failure in parsing
2428 */
2429
2430 struct exim_openssl_option {
2431 uschar *name;
2432 long value;
2433 };
2434 /* We could use a macro to expand, but we need the ifdef and not all the
2435 options document which version they were introduced in. Policylet: include
2436 all options unless explicitly for DTLS, let the administrator choose which
2437 to apply.
2438
2439 This list is current as of:
2440 ==> 1.0.1b <==
2441 Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev
2442 */
2443 static struct exim_openssl_option exim_openssl_options[] = {
2444 /* KEEP SORTED ALPHABETICALLY! */
2445 #ifdef SSL_OP_ALL
2446 { US"all", SSL_OP_ALL },
2447 #endif
2448 #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
2449 { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION },
2450 #endif
2451 #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE
2452 { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE },
2453 #endif
2454 #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
2455 { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS },
2456 #endif
2457 #ifdef SSL_OP_EPHEMERAL_RSA
2458 { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA },
2459 #endif
2460 #ifdef SSL_OP_LEGACY_SERVER_CONNECT
2461 { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT },
2462 #endif
2463 #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
2464 { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER },
2465 #endif
2466 #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG
2467 { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG },
2468 #endif
2469 #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING
2470 { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING },
2471 #endif
2472 #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG
2473 { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG },
2474 #endif
2475 #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
2476 { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG },
2477 #endif
2478 #ifdef SSL_OP_NO_COMPRESSION
2479 { US"no_compression", SSL_OP_NO_COMPRESSION },
2480 #endif
2481 #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
2482 { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION },
2483 #endif
2484 #ifdef SSL_OP_NO_SSLv2
2485 { US"no_sslv2", SSL_OP_NO_SSLv2 },
2486 #endif
2487 #ifdef SSL_OP_NO_SSLv3
2488 { US"no_sslv3", SSL_OP_NO_SSLv3 },
2489 #endif
2490 #ifdef SSL_OP_NO_TICKET
2491 { US"no_ticket", SSL_OP_NO_TICKET },
2492 #endif
2493 #ifdef SSL_OP_NO_TLSv1
2494 { US"no_tlsv1", SSL_OP_NO_TLSv1 },
2495 #endif
2496 #ifdef SSL_OP_NO_TLSv1_1
2497 #if SSL_OP_NO_TLSv1_1 == 0x00000400L
2498 /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */
2499 #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring
2500 #else
2501 { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 },
2502 #endif
2503 #endif
2504 #ifdef SSL_OP_NO_TLSv1_2
2505 { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 },
2506 #endif
2507 #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG
2508 { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG },
2509 #endif
2510 #ifdef SSL_OP_SINGLE_DH_USE
2511 { US"single_dh_use", SSL_OP_SINGLE_DH_USE },
2512 #endif
2513 #ifdef SSL_OP_SINGLE_ECDH_USE
2514 { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE },
2515 #endif
2516 #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG
2517 { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG },
2518 #endif
2519 #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
2520 { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG },
2521 #endif
2522 #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG
2523 { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG },
2524 #endif
2525 #ifdef SSL_OP_TLS_D5_BUG
2526 { US"tls_d5_bug", SSL_OP_TLS_D5_BUG },
2527 #endif
2528 #ifdef SSL_OP_TLS_ROLLBACK_BUG
2529 { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG },
2530 #endif
2531 };
2532 static int exim_openssl_options_size =
2533 sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option);
2534
2535
2536 static BOOL
2537 tls_openssl_one_option_parse(uschar *name, long *value)
2538 {
2539 int first = 0;
2540 int last = exim_openssl_options_size;
2541 while (last > first)
2542 {
2543 int middle = (first + last)/2;
2544 int c = Ustrcmp(name, exim_openssl_options[middle].name);
2545 if (c == 0)
2546 {
2547 *value = exim_openssl_options[middle].value;
2548 return TRUE;
2549 }
2550 else if (c > 0)
2551 first = middle + 1;
2552 else
2553 last = middle;
2554 }
2555 return FALSE;
2556 }
2557
2558
2559
2560
2561 /*************************************************
2562 * OpenSSL option parsing logic *
2563 *************************************************/
2564
2565 /* OpenSSL has a number of compatibility options which an administrator might
2566 reasonably wish to set. Interpret a list similarly to decode_bits(), so that
2567 we look like log_selector.
2568
2569 Arguments:
2570 option_spec the administrator-supplied string of options
2571 results ptr to long storage for the options bitmap
2572 Returns success or failure
2573 */
2574
2575 BOOL
2576 tls_openssl_options_parse(uschar *option_spec, long *results)
2577 {
2578 long result, item;
2579 uschar *s, *end;
2580 uschar keep_c;
2581 BOOL adding, item_parsed;
2582
2583 result = 0L;
2584 /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed
2585 * from default because it increases BEAST susceptibility. */
2586 #ifdef SSL_OP_NO_SSLv2
2587 result |= SSL_OP_NO_SSLv2;
2588 #endif
2589
2590 if (option_spec == NULL)
2591 {
2592 *results = result;
2593 return TRUE;
2594 }
2595
2596 for (s=option_spec; *s != '\0'; /**/)
2597 {
2598 while (isspace(*s)) ++s;
2599 if (*s == '\0')
2600 break;
2601 if (*s != '+' && *s != '-')
2602 {
2603 DEBUG(D_tls) debug_printf("malformed openssl option setting: "
2604 "+ or - expected but found \"%s\"\n", s);
2605 return FALSE;
2606 }
2607 adding = *s++ == '+';
2608 for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ;
2609 keep_c = *end;
2610 *end = '\0';
2611 item_parsed = tls_openssl_one_option_parse(s, &item);
2612 if (!item_parsed)
2613 {
2614 DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s);
2615 return FALSE;
2616 }
2617 DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n",
2618 adding ? "adding" : "removing", result, item, s);
2619 if (adding)
2620 result |= item;
2621 else
2622 result &= ~item;
2623 *end = keep_c;
2624 s = end;
2625 }
2626
2627 *results = result;
2628 return TRUE;
2629 }
2630
2631 /* vi: aw ai sw=2
2632 */
2633 /* End of tls-openssl.c */