Commit | Line | Data |
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059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
5a66c31b | 5 | /* Copyright (c) University of Cambridge 1995 - 2014 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
f5d78688 JH |
8 | /* Portions Copyright (c) The OpenSSL Project 1999 */ |
9 | ||
059ec3d9 PH |
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> | |
f2de3a33 | 25 | #ifndef DISABLE_OCSP |
e51c7be2 | 26 | # include <openssl/ocsp.h> |
3f7eeb86 | 27 | #endif |
85098ee7 JH |
28 | #ifdef EXPERIMENTAL_DANE |
29 | # include <danessl.h> | |
30 | #endif | |
31 | ||
3f7eeb86 | 32 | |
f2de3a33 JH |
33 | #ifndef DISABLE_OCSP |
34 | # define EXIM_OCSP_SKEW_SECONDS (300L) | |
35 | # define EXIM_OCSP_MAX_AGE (-1L) | |
3f7eeb86 | 36 | #endif |
059ec3d9 | 37 | |
3bcbbbe2 | 38 | #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT) |
e51c7be2 | 39 | # define EXIM_HAVE_OPENSSL_TLSEXT |
3bcbbbe2 PP |
40 | #endif |
41 | ||
67791ce4 JH |
42 | #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP) |
43 | # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile" | |
44 | # define DISABLE_OCSP | |
45 | #endif | |
46 | ||
059ec3d9 PH |
47 | /* Structure for collecting random data for seeding. */ |
48 | ||
49 | typedef struct randstuff { | |
9e3331ea TK |
50 | struct timeval tv; |
51 | pid_t p; | |
059ec3d9 PH |
52 | } randstuff; |
53 | ||
54 | /* Local static variables */ | |
55 | ||
a2ff477a JH |
56 | static BOOL client_verify_callback_called = FALSE; |
57 | static BOOL server_verify_callback_called = FALSE; | |
059ec3d9 PH |
58 | static const uschar *sid_ctx = US"exim"; |
59 | ||
d4f09789 PP |
60 | /* We have three different contexts to care about. |
61 | ||
62 | Simple case: client, `client_ctx` | |
63 | As a client, we can be doing a callout or cut-through delivery while receiving | |
64 | a message. So we have a client context, which should have options initialised | |
65 | from the SMTP Transport. | |
66 | ||
67 | Server: | |
68 | There are two cases: with and without ServerNameIndication from the client. | |
69 | Given TLS SNI, we can be using different keys, certs and various other | |
70 | configuration settings, because they're re-expanded with $tls_sni set. This | |
71 | allows vhosting with TLS. This SNI is sent in the handshake. | |
72 | A client might not send SNI, so we need a fallback, and an initial setup too. | |
73 | So as a server, we start out using `server_ctx`. | |
74 | If SNI is sent by the client, then we as server, mid-negotiation, try to clone | |
75 | `server_sni` from `server_ctx` and then initialise settings by re-expanding | |
76 | configuration. | |
77 | */ | |
78 | ||
817d9f57 JH |
79 | static SSL_CTX *client_ctx = NULL; |
80 | static SSL_CTX *server_ctx = NULL; | |
81 | static SSL *client_ssl = NULL; | |
82 | static SSL *server_ssl = NULL; | |
389ca47a | 83 | |
35731706 | 84 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 | 85 | static SSL_CTX *server_sni = NULL; |
35731706 | 86 | #endif |
059ec3d9 PH |
87 | |
88 | static char ssl_errstring[256]; | |
89 | ||
90 | static int ssl_session_timeout = 200; | |
a2ff477a JH |
91 | static BOOL client_verify_optional = FALSE; |
92 | static BOOL server_verify_optional = FALSE; | |
059ec3d9 | 93 | |
f5d78688 | 94 | static BOOL reexpand_tls_files_for_sni = FALSE; |
059ec3d9 PH |
95 | |
96 | ||
7be682ca PP |
97 | typedef struct tls_ext_ctx_cb { |
98 | uschar *certificate; | |
99 | uschar *privatekey; | |
f2de3a33 | 100 | #ifndef DISABLE_OCSP |
f5d78688 JH |
101 | BOOL is_server; |
102 | union { | |
103 | struct { | |
104 | uschar *file; | |
105 | uschar *file_expanded; | |
106 | OCSP_RESPONSE *response; | |
107 | } server; | |
108 | struct { | |
44662487 JH |
109 | X509_STORE *verify_store; /* non-null if status requested */ |
110 | BOOL verify_required; | |
f5d78688 JH |
111 | } client; |
112 | } u_ocsp; | |
3f7eeb86 | 113 | #endif |
7be682ca PP |
114 | uschar *dhparam; |
115 | /* these are cached from first expand */ | |
116 | uschar *server_cipher_list; | |
117 | /* only passed down to tls_error: */ | |
118 | host_item *host; | |
e51c7be2 JH |
119 | |
120 | #ifdef EXPERIMENTAL_CERTNAMES | |
121 | uschar * verify_cert_hostnames; | |
122 | #endif | |
a7538db1 JH |
123 | #ifdef EXPERIMENTAL_TPDA |
124 | uschar * event_action; | |
125 | #endif | |
7be682ca PP |
126 | } tls_ext_ctx_cb; |
127 | ||
128 | /* should figure out a cleanup of API to handle state preserved per | |
129 | implementation, for various reasons, which can be void * in the APIs. | |
130 | For now, we hack around it. */ | |
817d9f57 JH |
131 | tls_ext_ctx_cb *client_static_cbinfo = NULL; |
132 | tls_ext_ctx_cb *server_static_cbinfo = NULL; | |
7be682ca PP |
133 | |
134 | static int | |
983207c1 JH |
135 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
136 | int (*cert_vfy_cb)(int, X509_STORE_CTX *) ); | |
059ec3d9 | 137 | |
3f7eeb86 | 138 | /* Callbacks */ |
3bcbbbe2 | 139 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
3f7eeb86 | 140 | static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg); |
3bcbbbe2 | 141 | #endif |
f2de3a33 | 142 | #ifndef DISABLE_OCSP |
f5d78688 | 143 | static int tls_server_stapling_cb(SSL *s, void *arg); |
3f7eeb86 PP |
144 | #endif |
145 | ||
059ec3d9 PH |
146 | |
147 | /************************************************* | |
148 | * Handle TLS error * | |
149 | *************************************************/ | |
150 | ||
151 | /* Called from lots of places when errors occur before actually starting to do | |
152 | the TLS handshake, that is, while the session is still in clear. Always returns | |
153 | DEFER for a server and FAIL for a client so that most calls can use "return | |
154 | tls_error(...)" to do this processing and then give an appropriate return. A | |
155 | single function is used for both server and client, because it is called from | |
156 | some shared functions. | |
157 | ||
158 | Argument: | |
159 | prefix text to include in the logged error | |
160 | host NULL if setting up a server; | |
161 | the connected host if setting up a client | |
7199e1ee | 162 | msg error message or NULL if we should ask OpenSSL |
059ec3d9 PH |
163 | |
164 | Returns: OK/DEFER/FAIL | |
165 | */ | |
166 | ||
167 | static int | |
7199e1ee | 168 | tls_error(uschar *prefix, host_item *host, uschar *msg) |
059ec3d9 | 169 | { |
7199e1ee TF |
170 | if (msg == NULL) |
171 | { | |
172 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
5ca6d115 | 173 | msg = (uschar *)ssl_errstring; |
7199e1ee TF |
174 | } |
175 | ||
059ec3d9 PH |
176 | if (host == NULL) |
177 | { | |
7199e1ee | 178 | uschar *conn_info = smtp_get_connection_info(); |
5ca6d115 | 179 | if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) |
7199e1ee TF |
180 | conn_info += 5; |
181 | log_write(0, LOG_MAIN, "TLS error on %s (%s): %s", | |
182 | conn_info, prefix, msg); | |
059ec3d9 PH |
183 | return DEFER; |
184 | } | |
185 | else | |
186 | { | |
187 | log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s): %s", | |
7199e1ee | 188 | host->name, host->address, prefix, msg); |
059ec3d9 PH |
189 | return FAIL; |
190 | } | |
191 | } | |
192 | ||
193 | ||
194 | ||
195 | /************************************************* | |
196 | * Callback to generate RSA key * | |
197 | *************************************************/ | |
198 | ||
199 | /* | |
200 | Arguments: | |
201 | s SSL connection | |
202 | export not used | |
203 | keylength keylength | |
204 | ||
205 | Returns: pointer to generated key | |
206 | */ | |
207 | ||
208 | static RSA * | |
209 | rsa_callback(SSL *s, int export, int keylength) | |
210 | { | |
211 | RSA *rsa_key; | |
212 | export = export; /* Shut picky compilers up */ | |
213 | DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength); | |
214 | rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL); | |
215 | if (rsa_key == NULL) | |
216 | { | |
217 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
218 | log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s", | |
219 | ssl_errstring); | |
220 | return NULL; | |
221 | } | |
222 | return rsa_key; | |
223 | } | |
224 | ||
225 | ||
226 | ||
f5d78688 | 227 | /* Extreme debug |
f2de3a33 | 228 | #ifndef DISABLE_OCSP |
f5d78688 JH |
229 | void |
230 | x509_store_dump_cert_s_names(X509_STORE * store) | |
231 | { | |
232 | STACK_OF(X509_OBJECT) * roots= store->objs; | |
233 | int i; | |
234 | static uschar name[256]; | |
235 | ||
236 | for(i= 0; i<sk_X509_OBJECT_num(roots); i++) | |
237 | { | |
238 | X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i); | |
239 | if(tmp_obj->type == X509_LU_X509) | |
240 | { | |
241 | X509 * current_cert= tmp_obj->data.x509; | |
242 | X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name)); | |
243 | debug_printf(" %s\n", name); | |
244 | } | |
245 | } | |
246 | } | |
247 | #endif | |
248 | */ | |
249 | ||
059ec3d9 PH |
250 | |
251 | /************************************************* | |
252 | * Callback for verification * | |
253 | *************************************************/ | |
254 | ||
255 | /* The SSL library does certificate verification if set up to do so. This | |
256 | callback has the current yes/no state is in "state". If verification succeeded, | |
257 | we set up the tls_peerdn string. If verification failed, what happens depends | |
258 | on whether the client is required to present a verifiable certificate or not. | |
259 | ||
260 | If verification is optional, we change the state to yes, but still log the | |
261 | verification error. For some reason (it really would help to have proper | |
262 | documentation of OpenSSL), this callback function then gets called again, this | |
263 | time with state = 1. In fact, that's useful, because we can set up the peerdn | |
264 | value, but we must take care not to set the private verified flag on the second | |
265 | time through. | |
266 | ||
267 | Note: this function is not called if the client fails to present a certificate | |
268 | when asked. We get here only if a certificate has been received. Handling of | |
269 | optional verification for this case is done when requesting SSL to verify, by | |
270 | setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case. | |
271 | ||
a7538db1 JH |
272 | May be called multiple times for different issues with a certificate, even |
273 | for a given "depth" in the certificate chain. | |
274 | ||
059ec3d9 PH |
275 | Arguments: |
276 | state current yes/no state as 1/0 | |
277 | x509ctx certificate information. | |
a2ff477a | 278 | client TRUE for client startup, FALSE for server startup |
059ec3d9 PH |
279 | |
280 | Returns: 1 if verified, 0 if not | |
281 | */ | |
282 | ||
283 | static int | |
421aff85 JH |
284 | verify_callback(int state, X509_STORE_CTX *x509ctx, |
285 | tls_support *tlsp, BOOL *calledp, BOOL *optionalp) | |
059ec3d9 | 286 | { |
421aff85 | 287 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); |
a7538db1 | 288 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
059ec3d9 PH |
289 | static uschar txt[256]; |
290 | ||
e51c7be2 | 291 | X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt)); |
059ec3d9 PH |
292 | |
293 | if (state == 0) | |
294 | { | |
295 | log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s", | |
a7538db1 | 296 | depth, |
421aff85 | 297 | X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), |
059ec3d9 | 298 | txt); |
a2ff477a JH |
299 | tlsp->certificate_verified = FALSE; |
300 | *calledp = TRUE; | |
9d1c15ef JH |
301 | if (!*optionalp) |
302 | { | |
421aff85 | 303 | tlsp->peercert = X509_dup(cert); |
9d1c15ef JH |
304 | return 0; /* reject */ |
305 | } | |
059ec3d9 PH |
306 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
307 | "tls_try_verify_hosts)\n"); | |
059ec3d9 PH |
308 | } |
309 | ||
a7538db1 | 310 | else if (depth != 0) |
059ec3d9 | 311 | { |
a7538db1 | 312 | DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, txt); |
f2de3a33 | 313 | #ifndef DISABLE_OCSP |
f5d78688 JH |
314 | if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store) |
315 | { /* client, wanting stapling */ | |
316 | /* Add the server cert's signing chain as the one | |
317 | for the verification of the OCSP stapled information. */ | |
318 | ||
319 | if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, | |
421aff85 | 320 | cert)) |
f5d78688 JH |
321 | ERR_clear_error(); |
322 | } | |
a7538db1 JH |
323 | #endif |
324 | #ifdef EXPERIMENTAL_TPDA | |
325 | if (tlsp == &tls_out && client_static_cbinfo->event_action) | |
326 | { | |
327 | tlsp->peercert = X509_dup(cert); | |
328 | if (tpda_raise_event(client_static_cbinfo->event_action, | |
329 | US"tls:cert", string_sprintf("%d", depth)) == DEFER) | |
330 | { | |
331 | log_write(0, LOG_MAIN, "SSL verify denied by event-action: " | |
332 | "depth=%d cert=%s", depth, txt); | |
333 | tlsp->certificate_verified = FALSE; | |
334 | *calledp = TRUE; | |
335 | return 0; /* reject */ | |
336 | } | |
337 | X509_free(tlsp->peercert); | |
338 | tlsp->peercert = NULL; | |
339 | } | |
f5d78688 | 340 | #endif |
059ec3d9 PH |
341 | } |
342 | else | |
343 | { | |
e51c7be2 JH |
344 | #ifdef EXPERIMENTAL_CERTNAMES |
345 | uschar * verify_cert_hostnames; | |
346 | #endif | |
347 | ||
a2ff477a | 348 | tlsp->peerdn = txt; |
421aff85 | 349 | tlsp->peercert = X509_dup(cert); |
e51c7be2 JH |
350 | |
351 | #ifdef EXPERIMENTAL_CERTNAMES | |
352 | if ( tlsp == &tls_out | |
353 | && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames))) | |
354 | /* client, wanting hostname check */ | |
355 | ||
356 | # if OPENSSL_VERSION_NUMBER >= 0x010100000L || OPENSSL_VERSION_NUMBER >= 0x010002000L | |
d8e7834a JH |
357 | # ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
358 | # define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0 | |
359 | # endif | |
e51c7be2 JH |
360 | { |
361 | int sep = 0; | |
362 | uschar * list = verify_cert_hostnames; | |
363 | uschar * name; | |
d8e7834a JH |
364 | int rc; |
365 | while ((name = string_nextinlist(&list, &sep, NULL, 0))) | |
366 | if ((rc = X509_check_host(cert, name, 0, | |
367 | X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS))) | |
368 | { | |
369 | if (rc < 0) | |
370 | { | |
371 | log_write(0, LOG_MAIN, "SSL verify error: internal error\n"); | |
372 | name = NULL; | |
373 | } | |
e51c7be2 | 374 | break; |
d8e7834a | 375 | } |
e51c7be2 JH |
376 | if (!name) |
377 | { | |
378 | log_write(0, LOG_MAIN, | |
379 | "SSL verify error: certificate name mismatch: \"%s\"\n", txt); | |
380 | return 0; /* reject */ | |
381 | } | |
382 | } | |
383 | # else | |
384 | if (!tls_is_name_for_cert(verify_cert_hostnames, cert)) | |
385 | { | |
386 | log_write(0, LOG_MAIN, | |
387 | "SSL verify error: certificate name mismatch: \"%s\"\n", txt); | |
388 | return 0; /* reject */ | |
389 | } | |
390 | # endif | |
e5cccda9 | 391 | #endif /*EXPERIMENTAL_CERTNAMES*/ |
e51c7be2 | 392 | |
a7538db1 JH |
393 | #ifdef EXPERIMENTAL_TPDA |
394 | if (tlsp == &tls_out) | |
395 | { | |
396 | if (tpda_raise_event(client_static_cbinfo->event_action, | |
397 | US"tls:cert", US"0") == DEFER) | |
398 | { | |
399 | log_write(0, LOG_MAIN, "SSL verify denied by event-action: " | |
400 | "depth=0 cert=%s", txt); | |
401 | tlsp->certificate_verified = FALSE; | |
402 | *calledp = TRUE; | |
403 | return 0; /* reject */ | |
404 | } | |
405 | } | |
e51c7be2 JH |
406 | #endif |
407 | ||
93dcb1c2 JH |
408 | DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n", |
409 | *calledp ? "" : " authenticated", txt); | |
410 | if (!*calledp) tlsp->certificate_verified = TRUE; | |
411 | *calledp = TRUE; | |
059ec3d9 PH |
412 | } |
413 | ||
a7538db1 | 414 | return 1; /* accept, at least for this level */ |
059ec3d9 PH |
415 | } |
416 | ||
a2ff477a JH |
417 | static int |
418 | verify_callback_client(int state, X509_STORE_CTX *x509ctx) | |
419 | { | |
f5d78688 | 420 | return verify_callback(state, x509ctx, &tls_out, &client_verify_callback_called, &client_verify_optional); |
a2ff477a JH |
421 | } |
422 | ||
423 | static int | |
424 | verify_callback_server(int state, X509_STORE_CTX *x509ctx) | |
425 | { | |
f5d78688 | 426 | return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, &server_verify_optional); |
a2ff477a JH |
427 | } |
428 | ||
059ec3d9 | 429 | |
e5cccda9 | 430 | #ifdef EXPERIMENTAL_DANE |
53a7196b | 431 | |
e5cccda9 JH |
432 | /* This gets called *by* the dane library verify callback, which interposes |
433 | itself. | |
434 | */ | |
435 | static int | |
436 | verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx) | |
437 | { | |
438 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); | |
439 | static uschar txt[256]; | |
83b27293 JH |
440 | #ifdef EXPERIMENTAL_TPDA |
441 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); | |
442 | #endif | |
e5cccda9 JH |
443 | |
444 | X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt)); | |
445 | ||
446 | DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s\n", txt); | |
447 | tls_out.peerdn = txt; | |
448 | tls_out.peercert = X509_dup(cert); | |
449 | ||
83b27293 JH |
450 | #ifdef EXPERIMENTAL_TPDA |
451 | if (client_static_cbinfo->event_action) | |
452 | { | |
453 | if (tpda_raise_event(client_static_cbinfo->event_action, | |
454 | US"tls:cert", string_sprintf("%d", depth)) == DEFER) | |
455 | { | |
456 | log_write(0, LOG_MAIN, "DANE verify denied by event-action: " | |
457 | "depth=%d cert=%s", depth, txt); | |
458 | tls_out.certificate_verified = FALSE; | |
459 | return 0; /* reject */ | |
460 | } | |
461 | if (depth != 0) | |
462 | { | |
463 | X509_free(tls_out.peercert); | |
464 | tls_out.peercert = NULL; | |
465 | } | |
466 | } | |
467 | #endif | |
468 | ||
e5cccda9 | 469 | if (state == 1) |
53a7196b | 470 | tls_out.dane_verified = |
e5cccda9 JH |
471 | tls_out.certificate_verified = TRUE; |
472 | return 1; | |
473 | } | |
53a7196b JH |
474 | |
475 | #endif /*EXPERIMENTAL_DANE*/ | |
e5cccda9 | 476 | |
059ec3d9 PH |
477 | |
478 | /************************************************* | |
479 | * Information callback * | |
480 | *************************************************/ | |
481 | ||
482 | /* The SSL library functions call this from time to time to indicate what they | |
7be682ca PP |
483 | are doing. We copy the string to the debugging output when TLS debugging has |
484 | been requested. | |
059ec3d9 PH |
485 | |
486 | Arguments: | |
487 | s the SSL connection | |
488 | where | |
489 | ret | |
490 | ||
491 | Returns: nothing | |
492 | */ | |
493 | ||
494 | static void | |
495 | info_callback(SSL *s, int where, int ret) | |
496 | { | |
497 | where = where; | |
498 | ret = ret; | |
499 | DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s)); | |
500 | } | |
501 | ||
502 | ||
503 | ||
504 | /************************************************* | |
505 | * Initialize for DH * | |
506 | *************************************************/ | |
507 | ||
508 | /* If dhparam is set, expand it, and load up the parameters for DH encryption. | |
509 | ||
510 | Arguments: | |
a799883d | 511 | dhparam DH parameter file or fixed parameter identity string |
7199e1ee | 512 | host connected host, if client; NULL if server |
059ec3d9 PH |
513 | |
514 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
515 | */ | |
516 | ||
517 | static BOOL | |
a799883d | 518 | init_dh(SSL_CTX *sctx, uschar *dhparam, host_item *host) |
059ec3d9 | 519 | { |
059ec3d9 PH |
520 | BIO *bio; |
521 | DH *dh; | |
522 | uschar *dhexpanded; | |
a799883d | 523 | const char *pem; |
059ec3d9 PH |
524 | |
525 | if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded)) | |
526 | return FALSE; | |
527 | ||
0df4ab80 | 528 | if (!dhexpanded || !*dhexpanded) |
a799883d | 529 | bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1); |
a799883d | 530 | else if (dhexpanded[0] == '/') |
059ec3d9 | 531 | { |
0df4ab80 | 532 | if (!(bio = BIO_new_file(CS dhexpanded, "r"))) |
059ec3d9 | 533 | { |
7199e1ee | 534 | tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), |
a799883d PP |
535 | host, US strerror(errno)); |
536 | return FALSE; | |
059ec3d9 | 537 | } |
a799883d PP |
538 | } |
539 | else | |
540 | { | |
541 | if (Ustrcmp(dhexpanded, "none") == 0) | |
059ec3d9 | 542 | { |
a799883d PP |
543 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); |
544 | return TRUE; | |
059ec3d9 | 545 | } |
a799883d | 546 | |
0df4ab80 | 547 | if (!(pem = std_dh_prime_named(dhexpanded))) |
a799883d PP |
548 | { |
549 | tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded), | |
550 | host, US strerror(errno)); | |
551 | return FALSE; | |
552 | } | |
553 | bio = BIO_new_mem_buf(CS pem, -1); | |
554 | } | |
555 | ||
0df4ab80 | 556 | if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL))) |
a799883d | 557 | { |
059ec3d9 | 558 | BIO_free(bio); |
a799883d PP |
559 | tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded), |
560 | host, NULL); | |
561 | return FALSE; | |
562 | } | |
563 | ||
564 | /* Even if it is larger, we silently return success rather than cause things | |
565 | * to fail out, so that a too-large DH will not knock out all TLS; it's a | |
566 | * debatable choice. */ | |
567 | if ((8*DH_size(dh)) > tls_dh_max_bits) | |
568 | { | |
569 | DEBUG(D_tls) | |
570 | debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d", | |
571 | 8*DH_size(dh), tls_dh_max_bits); | |
572 | } | |
573 | else | |
574 | { | |
575 | SSL_CTX_set_tmp_dh(sctx, dh); | |
576 | DEBUG(D_tls) | |
577 | debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n", | |
578 | dhexpanded ? dhexpanded : US"default", 8*DH_size(dh)); | |
059ec3d9 PH |
579 | } |
580 | ||
a799883d PP |
581 | DH_free(dh); |
582 | BIO_free(bio); | |
583 | ||
584 | return TRUE; | |
059ec3d9 PH |
585 | } |
586 | ||
587 | ||
588 | ||
589 | ||
f2de3a33 | 590 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
591 | /************************************************* |
592 | * Load OCSP information into state * | |
593 | *************************************************/ | |
594 | ||
f5d78688 | 595 | /* Called to load the server OCSP response from the given file into memory, once |
3f7eeb86 PP |
596 | caller has determined this is needed. Checks validity. Debugs a message |
597 | if invalid. | |
598 | ||
599 | ASSUMES: single response, for single cert. | |
600 | ||
601 | Arguments: | |
602 | sctx the SSL_CTX* to update | |
603 | cbinfo various parts of session state | |
604 | expanded the filename putatively holding an OCSP response | |
605 | ||
606 | */ | |
607 | ||
608 | static void | |
f5d78688 | 609 | ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded) |
3f7eeb86 PP |
610 | { |
611 | BIO *bio; | |
612 | OCSP_RESPONSE *resp; | |
613 | OCSP_BASICRESP *basic_response; | |
614 | OCSP_SINGLERESP *single_response; | |
615 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
616 | X509_STORE *store; | |
617 | unsigned long verify_flags; | |
618 | int status, reason, i; | |
619 | ||
f5d78688 JH |
620 | cbinfo->u_ocsp.server.file_expanded = string_copy(expanded); |
621 | if (cbinfo->u_ocsp.server.response) | |
3f7eeb86 | 622 | { |
f5d78688 JH |
623 | OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response); |
624 | cbinfo->u_ocsp.server.response = NULL; | |
3f7eeb86 PP |
625 | } |
626 | ||
f5d78688 | 627 | bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb"); |
3f7eeb86 PP |
628 | if (!bio) |
629 | { | |
630 | DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", | |
f5d78688 | 631 | cbinfo->u_ocsp.server.file_expanded); |
3f7eeb86 PP |
632 | return; |
633 | } | |
634 | ||
635 | resp = d2i_OCSP_RESPONSE_bio(bio, NULL); | |
636 | BIO_free(bio); | |
637 | if (!resp) | |
638 | { | |
639 | DEBUG(D_tls) debug_printf("Error reading OCSP response.\n"); | |
640 | return; | |
641 | } | |
642 | ||
643 | status = OCSP_response_status(resp); | |
644 | if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) | |
645 | { | |
646 | DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", | |
647 | OCSP_response_status_str(status), status); | |
f5d78688 | 648 | goto bad; |
3f7eeb86 PP |
649 | } |
650 | ||
651 | basic_response = OCSP_response_get1_basic(resp); | |
652 | if (!basic_response) | |
653 | { | |
654 | DEBUG(D_tls) | |
655 | debug_printf("OCSP response parse error: unable to extract basic response.\n"); | |
f5d78688 | 656 | goto bad; |
3f7eeb86 PP |
657 | } |
658 | ||
659 | store = SSL_CTX_get_cert_store(sctx); | |
660 | verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ | |
661 | ||
662 | /* May need to expose ability to adjust those flags? | |
663 | OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT | |
664 | OCSP_TRUSTOTHER OCSP_NOINTERN */ | |
665 | ||
666 | i = OCSP_basic_verify(basic_response, NULL, store, verify_flags); | |
667 | if (i <= 0) | |
668 | { | |
669 | DEBUG(D_tls) { | |
670 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
671 | debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); | |
f5d78688 JH |
672 | } |
673 | goto bad; | |
3f7eeb86 PP |
674 | } |
675 | ||
676 | /* Here's the simplifying assumption: there's only one response, for the | |
677 | one certificate we use, and nothing for anything else in a chain. If this | |
678 | proves false, we need to extract a cert id from our issued cert | |
679 | (tls_certificate) and use that for OCSP_resp_find_status() (which finds the | |
680 | right cert in the stack and then calls OCSP_single_get0_status()). | |
681 | ||
682 | I'm hoping to avoid reworking a bunch more of how we handle state here. */ | |
683 | single_response = OCSP_resp_get0(basic_response, 0); | |
684 | if (!single_response) | |
685 | { | |
686 | DEBUG(D_tls) | |
687 | debug_printf("Unable to get first response from OCSP basic response.\n"); | |
f5d78688 | 688 | goto bad; |
3f7eeb86 PP |
689 | } |
690 | ||
691 | status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd); | |
f5d78688 | 692 | if (status != V_OCSP_CERTSTATUS_GOOD) |
3f7eeb86 | 693 | { |
f5d78688 JH |
694 | DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n", |
695 | OCSP_cert_status_str(status), status, | |
696 | OCSP_crl_reason_str(reason), reason); | |
697 | goto bad; | |
3f7eeb86 PP |
698 | } |
699 | ||
700 | if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
701 | { | |
702 | DEBUG(D_tls) debug_printf("OCSP status invalid times.\n"); | |
f5d78688 | 703 | goto bad; |
3f7eeb86 PP |
704 | } |
705 | ||
f5d78688 | 706 | supply_response: |
018058b2 | 707 | cbinfo->u_ocsp.server.response = resp; |
f5d78688 JH |
708 | return; |
709 | ||
710 | bad: | |
018058b2 JH |
711 | if (running_in_test_harness) |
712 | { | |
713 | extern char ** environ; | |
714 | uschar ** p; | |
715 | for (p = USS environ; *p != NULL; p++) | |
716 | if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) | |
717 | { | |
718 | DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n"); | |
719 | goto supply_response; | |
720 | } | |
721 | } | |
f5d78688 | 722 | return; |
3f7eeb86 | 723 | } |
f2de3a33 | 724 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
725 | |
726 | ||
727 | ||
728 | ||
7be682ca PP |
729 | /************************************************* |
730 | * Expand key and cert file specs * | |
731 | *************************************************/ | |
732 | ||
f5d78688 | 733 | /* Called once during tls_init and possibly again during TLS setup, for a |
7be682ca PP |
734 | new context, if Server Name Indication was used and tls_sni was seen in |
735 | the certificate string. | |
736 | ||
737 | Arguments: | |
738 | sctx the SSL_CTX* to update | |
739 | cbinfo various parts of session state | |
740 | ||
741 | Returns: OK/DEFER/FAIL | |
742 | */ | |
743 | ||
744 | static int | |
3f7eeb86 | 745 | tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo) |
7be682ca PP |
746 | { |
747 | uschar *expanded; | |
748 | ||
749 | if (cbinfo->certificate == NULL) | |
750 | return OK; | |
751 | ||
d9b2312b JH |
752 | if (Ustrstr(cbinfo->certificate, US"tls_sni") || |
753 | Ustrstr(cbinfo->certificate, US"tls_in_sni") || | |
754 | Ustrstr(cbinfo->certificate, US"tls_out_sni") | |
755 | ) | |
7be682ca PP |
756 | reexpand_tls_files_for_sni = TRUE; |
757 | ||
758 | if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded)) | |
759 | return DEFER; | |
760 | ||
761 | if (expanded != NULL) | |
762 | { | |
763 | DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); | |
764 | if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded)) | |
765 | return tls_error(string_sprintf( | |
766 | "SSL_CTX_use_certificate_chain_file file=%s", expanded), | |
767 | cbinfo->host, NULL); | |
768 | } | |
769 | ||
770 | if (cbinfo->privatekey != NULL && | |
771 | !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded)) | |
772 | return DEFER; | |
773 | ||
774 | /* If expansion was forced to fail, key_expanded will be NULL. If the result | |
775 | of the expansion is an empty string, ignore it also, and assume the private | |
776 | key is in the same file as the certificate. */ | |
777 | ||
778 | if (expanded != NULL && *expanded != 0) | |
779 | { | |
780 | DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); | |
781 | if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM)) | |
782 | return tls_error(string_sprintf( | |
783 | "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL); | |
784 | } | |
785 | ||
f2de3a33 | 786 | #ifndef DISABLE_OCSP |
f5d78688 | 787 | if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL) |
3f7eeb86 | 788 | { |
f5d78688 | 789 | if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded)) |
3f7eeb86 PP |
790 | return DEFER; |
791 | ||
792 | if (expanded != NULL && *expanded != 0) | |
793 | { | |
794 | DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded); | |
f5d78688 JH |
795 | if (cbinfo->u_ocsp.server.file_expanded && |
796 | (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0)) | |
3f7eeb86 PP |
797 | { |
798 | DEBUG(D_tls) | |
799 | debug_printf("tls_ocsp_file value unchanged, using existing values.\n"); | |
800 | } else { | |
801 | ocsp_load_response(sctx, cbinfo, expanded); | |
802 | } | |
803 | } | |
804 | } | |
805 | #endif | |
806 | ||
7be682ca PP |
807 | return OK; |
808 | } | |
809 | ||
810 | ||
811 | ||
812 | ||
813 | /************************************************* | |
814 | * Callback to handle SNI * | |
815 | *************************************************/ | |
816 | ||
817 | /* Called when acting as server during the TLS session setup if a Server Name | |
818 | Indication extension was sent by the client. | |
819 | ||
820 | API documentation is OpenSSL s_server.c implementation. | |
821 | ||
822 | Arguments: | |
823 | s SSL* of the current session | |
824 | ad unknown (part of OpenSSL API) (unused) | |
825 | arg Callback of "our" registered data | |
826 | ||
827 | Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK} | |
828 | */ | |
829 | ||
3bcbbbe2 | 830 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
7be682ca PP |
831 | static int |
832 | tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg) | |
833 | { | |
834 | const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); | |
3f7eeb86 | 835 | tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; |
7be682ca | 836 | int rc; |
3f0945ff | 837 | int old_pool = store_pool; |
7be682ca PP |
838 | |
839 | if (!servername) | |
840 | return SSL_TLSEXT_ERR_OK; | |
841 | ||
3f0945ff | 842 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername, |
7be682ca PP |
843 | reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)"); |
844 | ||
845 | /* Make the extension value available for expansion */ | |
3f0945ff | 846 | store_pool = POOL_PERM; |
817d9f57 | 847 | tls_in.sni = string_copy(US servername); |
3f0945ff | 848 | store_pool = old_pool; |
7be682ca PP |
849 | |
850 | if (!reexpand_tls_files_for_sni) | |
851 | return SSL_TLSEXT_ERR_OK; | |
852 | ||
853 | /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually; | |
854 | not confident that memcpy wouldn't break some internal reference counting. | |
855 | Especially since there's a references struct member, which would be off. */ | |
856 | ||
0df4ab80 | 857 | if (!(server_sni = SSL_CTX_new(SSLv23_server_method()))) |
7be682ca PP |
858 | { |
859 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
860 | DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring); | |
861 | return SSL_TLSEXT_ERR_NOACK; | |
862 | } | |
863 | ||
864 | /* Not sure how many of these are actually needed, since SSL object | |
865 | already exists. Might even need this selfsame callback, for reneg? */ | |
866 | ||
817d9f57 JH |
867 | SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx)); |
868 | SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx)); | |
869 | SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); | |
870 | SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); | |
871 | SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); | |
872 | SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); | |
7be682ca | 873 | if (cbinfo->server_cipher_list) |
817d9f57 | 874 | SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list); |
f2de3a33 | 875 | #ifndef DISABLE_OCSP |
f5d78688 | 876 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 877 | { |
f5d78688 | 878 | SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb); |
14c7b357 | 879 | SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo); |
3f7eeb86 PP |
880 | } |
881 | #endif | |
7be682ca | 882 | |
983207c1 | 883 | rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server); |
7be682ca PP |
884 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
885 | ||
3f7eeb86 PP |
886 | /* do this after setup_certs, because this can require the certs for verifying |
887 | OCSP information. */ | |
817d9f57 | 888 | rc = tls_expand_session_files(server_sni, cbinfo); |
7be682ca PP |
889 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
890 | ||
0df4ab80 JH |
891 | if (!init_dh(server_sni, cbinfo->dhparam, NULL)) |
892 | return SSL_TLSEXT_ERR_NOACK; | |
a799883d | 893 | |
7be682ca | 894 | DEBUG(D_tls) debug_printf("Switching SSL context.\n"); |
817d9f57 | 895 | SSL_set_SSL_CTX(s, server_sni); |
7be682ca PP |
896 | |
897 | return SSL_TLSEXT_ERR_OK; | |
898 | } | |
3bcbbbe2 | 899 | #endif /* EXIM_HAVE_OPENSSL_TLSEXT */ |
7be682ca PP |
900 | |
901 | ||
902 | ||
903 | ||
f2de3a33 | 904 | #ifndef DISABLE_OCSP |
f5d78688 | 905 | |
3f7eeb86 PP |
906 | /************************************************* |
907 | * Callback to handle OCSP Stapling * | |
908 | *************************************************/ | |
909 | ||
910 | /* Called when acting as server during the TLS session setup if the client | |
911 | requests OCSP information with a Certificate Status Request. | |
912 | ||
913 | Documentation via openssl s_server.c and the Apache patch from the OpenSSL | |
914 | project. | |
915 | ||
916 | */ | |
917 | ||
918 | static int | |
f5d78688 | 919 | tls_server_stapling_cb(SSL *s, void *arg) |
3f7eeb86 PP |
920 | { |
921 | const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; | |
922 | uschar *response_der; | |
923 | int response_der_len; | |
924 | ||
af4a1bca JH |
925 | DEBUG(D_tls) |
926 | debug_printf("Received TLS status request (OCSP stapling); %s response.", | |
f5d78688 JH |
927 | cbinfo->u_ocsp.server.response ? "have" : "lack"); |
928 | ||
44662487 | 929 | tls_in.ocsp = OCSP_NOT_RESP; |
f5d78688 | 930 | if (!cbinfo->u_ocsp.server.response) |
3f7eeb86 PP |
931 | return SSL_TLSEXT_ERR_NOACK; |
932 | ||
933 | response_der = NULL; | |
44662487 JH |
934 | response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response, |
935 | &response_der); | |
3f7eeb86 PP |
936 | if (response_der_len <= 0) |
937 | return SSL_TLSEXT_ERR_NOACK; | |
938 | ||
5e55c7a9 | 939 | SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len); |
44662487 | 940 | tls_in.ocsp = OCSP_VFIED; |
3f7eeb86 PP |
941 | return SSL_TLSEXT_ERR_OK; |
942 | } | |
943 | ||
3f7eeb86 | 944 | |
f5d78688 JH |
945 | static void |
946 | time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time) | |
947 | { | |
948 | BIO_printf(bp, "\t%s: ", str); | |
949 | ASN1_GENERALIZEDTIME_print(bp, time); | |
950 | BIO_puts(bp, "\n"); | |
951 | } | |
952 | ||
953 | static int | |
954 | tls_client_stapling_cb(SSL *s, void *arg) | |
955 | { | |
956 | tls_ext_ctx_cb * cbinfo = arg; | |
957 | const unsigned char * p; | |
958 | int len; | |
959 | OCSP_RESPONSE * rsp; | |
960 | OCSP_BASICRESP * bs; | |
961 | int i; | |
962 | ||
963 | DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):"); | |
964 | len = SSL_get_tlsext_status_ocsp_resp(s, &p); | |
965 | if(!p) | |
966 | { | |
44662487 JH |
967 | /* Expect this when we requested ocsp but got none */ |
968 | if ( cbinfo->u_ocsp.client.verify_required | |
969 | && log_extra_selector & LX_tls_cipher) | |
970 | log_write(0, LOG_MAIN, "Received TLS status callback, null content"); | |
f5d78688 JH |
971 | else |
972 | DEBUG(D_tls) debug_printf(" null\n"); | |
44662487 | 973 | return cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 974 | } |
018058b2 | 975 | |
f5d78688 JH |
976 | if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) |
977 | { | |
018058b2 | 978 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 | 979 | if (log_extra_selector & LX_tls_cipher) |
1eca31ca | 980 | log_write(0, LOG_MAIN, "Received TLS cert status response, parse error"); |
f5d78688 JH |
981 | else |
982 | DEBUG(D_tls) debug_printf(" parse error\n"); | |
983 | return 0; | |
984 | } | |
985 | ||
986 | if(!(bs = OCSP_response_get1_basic(rsp))) | |
987 | { | |
018058b2 | 988 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 | 989 | if (log_extra_selector & LX_tls_cipher) |
1eca31ca | 990 | log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response"); |
f5d78688 JH |
991 | else |
992 | DEBUG(D_tls) debug_printf(" error parsing response\n"); | |
993 | OCSP_RESPONSE_free(rsp); | |
994 | return 0; | |
995 | } | |
996 | ||
997 | /* We'd check the nonce here if we'd put one in the request. */ | |
998 | /* However that would defeat cacheability on the server so we don't. */ | |
999 | ||
f5d78688 JH |
1000 | /* This section of code reworked from OpenSSL apps source; |
1001 | The OpenSSL Project retains copyright: | |
1002 | Copyright (c) 1999 The OpenSSL Project. All rights reserved. | |
1003 | */ | |
1004 | { | |
1005 | BIO * bp = NULL; | |
f5d78688 JH |
1006 | int status, reason; |
1007 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
1008 | ||
1009 | DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE); | |
1010 | ||
1011 | /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */ | |
1012 | ||
1013 | /* Use the chain that verified the server cert to verify the stapled info */ | |
1014 | /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */ | |
1015 | ||
44662487 JH |
1016 | if ((i = OCSP_basic_verify(bs, NULL, |
1017 | cbinfo->u_ocsp.client.verify_store, 0)) <= 0) | |
f5d78688 | 1018 | { |
018058b2 | 1019 | tls_out.ocsp = OCSP_FAILED; |
1eca31ca JH |
1020 | if (log_extra_selector & LX_tls_cipher) |
1021 | log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable"); | |
f5d78688 JH |
1022 | BIO_printf(bp, "OCSP response verify failure\n"); |
1023 | ERR_print_errors(bp); | |
44662487 | 1024 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 JH |
1025 | goto out; |
1026 | } | |
1027 | ||
1028 | BIO_printf(bp, "OCSP response well-formed and signed OK\n"); | |
1029 | ||
1030 | { | |
1031 | STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; | |
1032 | OCSP_SINGLERESP * single; | |
1033 | ||
1034 | if (sk_OCSP_SINGLERESP_num(sresp) != 1) | |
1035 | { | |
018058b2 | 1036 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1037 | log_write(0, LOG_MAIN, "OCSP stapling " |
1038 | "with multiple responses not handled"); | |
1039 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
f5d78688 JH |
1040 | goto out; |
1041 | } | |
1042 | single = OCSP_resp_get0(bs, 0); | |
44662487 JH |
1043 | status = OCSP_single_get0_status(single, &reason, &rev, |
1044 | &thisupd, &nextupd); | |
f5d78688 JH |
1045 | } |
1046 | ||
f5d78688 JH |
1047 | DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd); |
1048 | DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd); | |
44662487 JH |
1049 | if (!OCSP_check_validity(thisupd, nextupd, |
1050 | EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
f5d78688 | 1051 | { |
018058b2 | 1052 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
1053 | DEBUG(D_tls) ERR_print_errors(bp); |
1054 | log_write(0, LOG_MAIN, "Server OSCP dates invalid"); | |
44662487 | 1055 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 1056 | } |
44662487 | 1057 | else |
f5d78688 | 1058 | { |
44662487 JH |
1059 | DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n", |
1060 | OCSP_cert_status_str(status)); | |
1061 | switch(status) | |
1062 | { | |
1063 | case V_OCSP_CERTSTATUS_GOOD: | |
44662487 | 1064 | tls_out.ocsp = OCSP_VFIED; |
018058b2 | 1065 | i = 1; |
44662487 JH |
1066 | break; |
1067 | case V_OCSP_CERTSTATUS_REVOKED: | |
018058b2 | 1068 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1069 | log_write(0, LOG_MAIN, "Server certificate revoked%s%s", |
1070 | reason != -1 ? "; reason: " : "", | |
1071 | reason != -1 ? OCSP_crl_reason_str(reason) : ""); | |
1072 | DEBUG(D_tls) time_print(bp, "Revocation Time", rev); | |
1073 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1074 | break; | |
1075 | default: | |
018058b2 | 1076 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1077 | log_write(0, LOG_MAIN, |
1078 | "Server certificate status unknown, in OCSP stapling"); | |
1079 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1080 | break; | |
1081 | } | |
f5d78688 JH |
1082 | } |
1083 | out: | |
1084 | BIO_free(bp); | |
1085 | } | |
1086 | ||
1087 | OCSP_RESPONSE_free(rsp); | |
1088 | return i; | |
1089 | } | |
f2de3a33 | 1090 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
1091 | |
1092 | ||
059ec3d9 PH |
1093 | /************************************************* |
1094 | * Initialize for TLS * | |
1095 | *************************************************/ | |
1096 | ||
e51c7be2 JH |
1097 | /* Called from both server and client code, to do preliminary initialization |
1098 | of the library. We allocate and return a context structure. | |
059ec3d9 PH |
1099 | |
1100 | Arguments: | |
946ecbe0 | 1101 | ctxp returned SSL context |
059ec3d9 PH |
1102 | host connected host, if client; NULL if server |
1103 | dhparam DH parameter file | |
1104 | certificate certificate file | |
1105 | privatekey private key | |
f5d78688 | 1106 | ocsp_file file of stapling info (server); flag for require ocsp (client) |
059ec3d9 | 1107 | addr address if client; NULL if server (for some randomness) |
946ecbe0 | 1108 | cbp place to put allocated callback context |
059ec3d9 PH |
1109 | |
1110 | Returns: OK/DEFER/FAIL | |
1111 | */ | |
1112 | ||
1113 | static int | |
817d9f57 | 1114 | tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate, |
3f7eeb86 | 1115 | uschar *privatekey, |
f2de3a33 | 1116 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1117 | uschar *ocsp_file, |
1118 | #endif | |
817d9f57 | 1119 | address_item *addr, tls_ext_ctx_cb ** cbp) |
059ec3d9 | 1120 | { |
77bb000f | 1121 | long init_options; |
7be682ca | 1122 | int rc; |
77bb000f | 1123 | BOOL okay; |
a7538db1 | 1124 | tls_ext_ctx_cb * cbinfo; |
7be682ca PP |
1125 | |
1126 | cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); | |
1127 | cbinfo->certificate = certificate; | |
1128 | cbinfo->privatekey = privatekey; | |
f2de3a33 | 1129 | #ifndef DISABLE_OCSP |
f5d78688 JH |
1130 | if ((cbinfo->is_server = host==NULL)) |
1131 | { | |
1132 | cbinfo->u_ocsp.server.file = ocsp_file; | |
1133 | cbinfo->u_ocsp.server.file_expanded = NULL; | |
1134 | cbinfo->u_ocsp.server.response = NULL; | |
1135 | } | |
1136 | else | |
1137 | cbinfo->u_ocsp.client.verify_store = NULL; | |
3f7eeb86 | 1138 | #endif |
7be682ca | 1139 | cbinfo->dhparam = dhparam; |
0df4ab80 | 1140 | cbinfo->server_cipher_list = NULL; |
7be682ca | 1141 | cbinfo->host = host; |
a7538db1 JH |
1142 | #ifdef EXPERIMENTAL_TPDA |
1143 | cbinfo->event_action = NULL; | |
1144 | #endif | |
77bb000f | 1145 | |
059ec3d9 PH |
1146 | SSL_load_error_strings(); /* basic set up */ |
1147 | OpenSSL_add_ssl_algorithms(); | |
1148 | ||
388d6564 | 1149 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) |
77bb000f | 1150 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the |
a0475b69 TK |
1151 | list of available digests. */ |
1152 | EVP_add_digest(EVP_sha256()); | |
cf1ef1a9 | 1153 | #endif |
a0475b69 | 1154 | |
f0f5a555 PP |
1155 | /* Create a context. |
1156 | The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant | |
1157 | negotiation in the different methods; as far as I can tell, the only | |
1158 | *_{server,client}_method which allows negotiation is SSLv23, which exists even | |
1159 | when OpenSSL is built without SSLv2 support. | |
1160 | By disabling with openssl_options, we can let admins re-enable with the | |
1161 | existing knob. */ | |
059ec3d9 | 1162 | |
817d9f57 | 1163 | *ctxp = SSL_CTX_new((host == NULL)? |
059ec3d9 PH |
1164 | SSLv23_server_method() : SSLv23_client_method()); |
1165 | ||
817d9f57 | 1166 | if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL); |
059ec3d9 PH |
1167 | |
1168 | /* It turns out that we need to seed the random number generator this early in | |
1169 | order to get the full complement of ciphers to work. It took me roughly a day | |
1170 | of work to discover this by experiment. | |
1171 | ||
1172 | On systems that have /dev/urandom, SSL may automatically seed itself from | |
1173 | there. Otherwise, we have to make something up as best we can. Double check | |
1174 | afterwards. */ | |
1175 | ||
1176 | if (!RAND_status()) | |
1177 | { | |
1178 | randstuff r; | |
9e3331ea | 1179 | gettimeofday(&r.tv, NULL); |
059ec3d9 PH |
1180 | r.p = getpid(); |
1181 | ||
1182 | RAND_seed((uschar *)(&r), sizeof(r)); | |
1183 | RAND_seed((uschar *)big_buffer, big_buffer_size); | |
1184 | if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr)); | |
1185 | ||
1186 | if (!RAND_status()) | |
7199e1ee | 1187 | return tls_error(US"RAND_status", host, |
5ca6d115 | 1188 | US"unable to seed random number generator"); |
059ec3d9 PH |
1189 | } |
1190 | ||
1191 | /* Set up the information callback, which outputs if debugging is at a suitable | |
1192 | level. */ | |
1193 | ||
817d9f57 | 1194 | SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback); |
059ec3d9 | 1195 | |
c80c5570 | 1196 | /* Automatically re-try reads/writes after renegotiation. */ |
817d9f57 | 1197 | (void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY); |
c80c5570 | 1198 | |
77bb000f PP |
1199 | /* Apply administrator-supplied work-arounds. |
1200 | Historically we applied just one requested option, | |
1201 | SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we | |
1202 | moved to an administrator-controlled list of options to specify and | |
1203 | grandfathered in the first one as the default value for "openssl_options". | |
059ec3d9 | 1204 | |
77bb000f PP |
1205 | No OpenSSL version number checks: the options we accept depend upon the |
1206 | availability of the option value macros from OpenSSL. */ | |
059ec3d9 | 1207 | |
77bb000f PP |
1208 | okay = tls_openssl_options_parse(openssl_options, &init_options); |
1209 | if (!okay) | |
73a46702 | 1210 | return tls_error(US"openssl_options parsing failed", host, NULL); |
77bb000f PP |
1211 | |
1212 | if (init_options) | |
1213 | { | |
1214 | DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); | |
817d9f57 | 1215 | if (!(SSL_CTX_set_options(*ctxp, init_options))) |
77bb000f PP |
1216 | return tls_error(string_sprintf( |
1217 | "SSL_CTX_set_option(%#lx)", init_options), host, NULL); | |
1218 | } | |
1219 | else | |
1220 | DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); | |
059ec3d9 PH |
1221 | |
1222 | /* Initialize with DH parameters if supplied */ | |
1223 | ||
817d9f57 | 1224 | if (!init_dh(*ctxp, dhparam, host)) return DEFER; |
059ec3d9 | 1225 | |
3f7eeb86 | 1226 | /* Set up certificate and key (and perhaps OCSP info) */ |
059ec3d9 | 1227 | |
817d9f57 | 1228 | rc = tls_expand_session_files(*ctxp, cbinfo); |
7be682ca | 1229 | if (rc != OK) return rc; |
c91535f3 | 1230 | |
7be682ca | 1231 | /* If we need to handle SNI, do so */ |
3bcbbbe2 | 1232 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
f5d78688 | 1233 | if (host == NULL) /* server */ |
3f0945ff | 1234 | { |
f2de3a33 | 1235 | # ifndef DISABLE_OCSP |
f5d78688 | 1236 | /* We check u_ocsp.server.file, not server.response, because we care about if |
3f7eeb86 PP |
1237 | the option exists, not what the current expansion might be, as SNI might |
1238 | change the certificate and OCSP file in use between now and the time the | |
1239 | callback is invoked. */ | |
f5d78688 | 1240 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1241 | { |
f5d78688 | 1242 | SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb); |
5e55c7a9 | 1243 | SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo); |
3f7eeb86 | 1244 | } |
f5d78688 | 1245 | # endif |
3f0945ff PP |
1246 | /* We always do this, so that $tls_sni is available even if not used in |
1247 | tls_certificate */ | |
817d9f57 JH |
1248 | SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb); |
1249 | SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo); | |
3f0945ff | 1250 | } |
f2de3a33 | 1251 | # ifndef DISABLE_OCSP |
f5d78688 JH |
1252 | else /* client */ |
1253 | if(ocsp_file) /* wanting stapling */ | |
1254 | { | |
1255 | if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new())) | |
1256 | { | |
1257 | DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n"); | |
1258 | return FAIL; | |
1259 | } | |
1260 | SSL_CTX_set_tlsext_status_cb(*ctxp, tls_client_stapling_cb); | |
1261 | SSL_CTX_set_tlsext_status_arg(*ctxp, cbinfo); | |
1262 | } | |
1263 | # endif | |
7be682ca | 1264 | #endif |
059ec3d9 | 1265 | |
e51c7be2 JH |
1266 | #ifdef EXPERIMENTAL_CERTNAMES |
1267 | cbinfo->verify_cert_hostnames = NULL; | |
1268 | #endif | |
1269 | ||
059ec3d9 PH |
1270 | /* Set up the RSA callback */ |
1271 | ||
817d9f57 | 1272 | SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback); |
059ec3d9 PH |
1273 | |
1274 | /* Finally, set the timeout, and we are done */ | |
1275 | ||
817d9f57 | 1276 | SSL_CTX_set_timeout(*ctxp, ssl_session_timeout); |
059ec3d9 | 1277 | DEBUG(D_tls) debug_printf("Initialized TLS\n"); |
7be682ca | 1278 | |
817d9f57 | 1279 | *cbp = cbinfo; |
7be682ca | 1280 | |
059ec3d9 PH |
1281 | return OK; |
1282 | } | |
1283 | ||
1284 | ||
1285 | ||
1286 | ||
1287 | /************************************************* | |
1288 | * Get name of cipher in use * | |
1289 | *************************************************/ | |
1290 | ||
817d9f57 | 1291 | /* |
059ec3d9 | 1292 | Argument: pointer to an SSL structure for the connection |
817d9f57 JH |
1293 | buffer to use for answer |
1294 | size of buffer | |
1295 | pointer to number of bits for cipher | |
059ec3d9 PH |
1296 | Returns: nothing |
1297 | */ | |
1298 | ||
1299 | static void | |
817d9f57 | 1300 | construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits) |
059ec3d9 | 1301 | { |
57b3a7f5 PP |
1302 | /* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't |
1303 | yet reflect that. It should be a safe change anyway, even 0.9.8 versions have | |
1304 | the accessor functions use const in the prototype. */ | |
1305 | const SSL_CIPHER *c; | |
d9784128 | 1306 | const uschar *ver; |
059ec3d9 | 1307 | |
d9784128 | 1308 | ver = (const uschar *)SSL_get_version(ssl); |
059ec3d9 | 1309 | |
57b3a7f5 | 1310 | c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); |
817d9f57 | 1311 | SSL_CIPHER_get_bits(c, bits); |
059ec3d9 | 1312 | |
817d9f57 JH |
1313 | string_format(cipherbuf, bsize, "%s:%s:%u", ver, |
1314 | SSL_CIPHER_get_name(c), *bits); | |
059ec3d9 PH |
1315 | |
1316 | DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf); | |
1317 | } | |
1318 | ||
1319 | ||
1320 | ||
1321 | ||
1322 | ||
1323 | /************************************************* | |
1324 | * Set up for verifying certificates * | |
1325 | *************************************************/ | |
1326 | ||
1327 | /* Called by both client and server startup | |
1328 | ||
1329 | Arguments: | |
7be682ca | 1330 | sctx SSL_CTX* to initialise |
059ec3d9 PH |
1331 | certs certs file or NULL |
1332 | crl CRL file or NULL | |
1333 | host NULL in a server; the remote host in a client | |
1334 | optional TRUE if called from a server for a host in tls_try_verify_hosts; | |
1335 | otherwise passed as FALSE | |
983207c1 | 1336 | cert_vfy_cb Callback function for certificate verification |
059ec3d9 PH |
1337 | |
1338 | Returns: OK/DEFER/FAIL | |
1339 | */ | |
1340 | ||
1341 | static int | |
983207c1 JH |
1342 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
1343 | int (*cert_vfy_cb)(int, X509_STORE_CTX *) ) | |
059ec3d9 PH |
1344 | { |
1345 | uschar *expcerts, *expcrl; | |
1346 | ||
1347 | if (!expand_check(certs, US"tls_verify_certificates", &expcerts)) | |
1348 | return DEFER; | |
1349 | ||
26e72755 | 1350 | if (expcerts != NULL && *expcerts != '\0') |
059ec3d9 PH |
1351 | { |
1352 | struct stat statbuf; | |
7be682ca | 1353 | if (!SSL_CTX_set_default_verify_paths(sctx)) |
7199e1ee | 1354 | return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL); |
059ec3d9 PH |
1355 | |
1356 | if (Ustat(expcerts, &statbuf) < 0) | |
1357 | { | |
1358 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1359 | "failed to stat %s for certificates", expcerts); | |
1360 | return DEFER; | |
1361 | } | |
1362 | else | |
1363 | { | |
1364 | uschar *file, *dir; | |
1365 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
1366 | { file = NULL; dir = expcerts; } | |
1367 | else | |
1368 | { file = expcerts; dir = NULL; } | |
1369 | ||
1370 | /* If a certificate file is empty, the next function fails with an | |
1371 | unhelpful error message. If we skip it, we get the correct behaviour (no | |
1372 | certificates are recognized, but the error message is still misleading (it | |
1373 | says no certificate was supplied.) But this is better. */ | |
1374 | ||
1375 | if ((file == NULL || statbuf.st_size > 0) && | |
7be682ca | 1376 | !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) |
7199e1ee | 1377 | return tls_error(US"SSL_CTX_load_verify_locations", host, NULL); |
059ec3d9 PH |
1378 | |
1379 | if (file != NULL) | |
1380 | { | |
7be682ca | 1381 | SSL_CTX_set_client_CA_list(sctx, SSL_load_client_CA_file(CS file)); |
059ec3d9 PH |
1382 | } |
1383 | } | |
1384 | ||
1385 | /* Handle a certificate revocation list. */ | |
1386 | ||
1387 | #if OPENSSL_VERSION_NUMBER > 0x00907000L | |
1388 | ||
8b417f2c PH |
1389 | /* This bit of code is now the version supplied by Lars Mainka. (I have |
1390 | * merely reformatted it into the Exim code style.) | |
1391 | ||
1392 | * "From here I changed the code to add support for multiple crl's | |
1393 | * in pem format in one file or to support hashed directory entries in | |
1394 | * pem format instead of a file. This method now uses the library function | |
1395 | * X509_STORE_load_locations to add the CRL location to the SSL context. | |
1396 | * OpenSSL will then handle the verify against CA certs and CRLs by | |
1397 | * itself in the verify callback." */ | |
1398 | ||
059ec3d9 PH |
1399 | if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER; |
1400 | if (expcrl != NULL && *expcrl != 0) | |
1401 | { | |
8b417f2c PH |
1402 | struct stat statbufcrl; |
1403 | if (Ustat(expcrl, &statbufcrl) < 0) | |
1404 | { | |
1405 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1406 | "failed to stat %s for certificates revocation lists", expcrl); | |
1407 | return DEFER; | |
1408 | } | |
1409 | else | |
059ec3d9 | 1410 | { |
8b417f2c PH |
1411 | /* is it a file or directory? */ |
1412 | uschar *file, *dir; | |
7be682ca | 1413 | X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx); |
8b417f2c | 1414 | if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR) |
059ec3d9 | 1415 | { |
8b417f2c PH |
1416 | file = NULL; |
1417 | dir = expcrl; | |
1418 | DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir); | |
059ec3d9 PH |
1419 | } |
1420 | else | |
1421 | { | |
8b417f2c PH |
1422 | file = expcrl; |
1423 | dir = NULL; | |
1424 | DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); | |
059ec3d9 | 1425 | } |
8b417f2c | 1426 | if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) |
7199e1ee | 1427 | return tls_error(US"X509_STORE_load_locations", host, NULL); |
8b417f2c PH |
1428 | |
1429 | /* setting the flags to check against the complete crl chain */ | |
1430 | ||
1431 | X509_STORE_set_flags(cvstore, | |
1432 | X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL); | |
059ec3d9 | 1433 | } |
059ec3d9 PH |
1434 | } |
1435 | ||
1436 | #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ | |
1437 | ||
1438 | /* If verification is optional, don't fail if no certificate */ | |
1439 | ||
7be682ca | 1440 | SSL_CTX_set_verify(sctx, |
059ec3d9 | 1441 | SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT), |
983207c1 | 1442 | cert_vfy_cb); |
059ec3d9 PH |
1443 | } |
1444 | ||
1445 | return OK; | |
1446 | } | |
1447 | ||
1448 | ||
1449 | ||
1450 | /************************************************* | |
1451 | * Start a TLS session in a server * | |
1452 | *************************************************/ | |
1453 | ||
1454 | /* This is called when Exim is running as a server, after having received | |
1455 | the STARTTLS command. It must respond to that command, and then negotiate | |
1456 | a TLS session. | |
1457 | ||
1458 | Arguments: | |
1459 | require_ciphers allowed ciphers | |
1460 | ||
1461 | Returns: OK on success | |
1462 | DEFER for errors before the start of the negotiation | |
1463 | FAIL for errors during the negotation; the server can't | |
1464 | continue running. | |
1465 | */ | |
1466 | ||
1467 | int | |
17c76198 | 1468 | tls_server_start(const uschar *require_ciphers) |
059ec3d9 PH |
1469 | { |
1470 | int rc; | |
1471 | uschar *expciphers; | |
7be682ca | 1472 | tls_ext_ctx_cb *cbinfo; |
817d9f57 | 1473 | static uschar cipherbuf[256]; |
059ec3d9 PH |
1474 | |
1475 | /* Check for previous activation */ | |
1476 | ||
817d9f57 | 1477 | if (tls_in.active >= 0) |
059ec3d9 | 1478 | { |
5ca6d115 | 1479 | tls_error(US"STARTTLS received after TLS started", NULL, US""); |
059ec3d9 PH |
1480 | smtp_printf("554 Already in TLS\r\n"); |
1481 | return FAIL; | |
1482 | } | |
1483 | ||
1484 | /* Initialize the SSL library. If it fails, it will already have logged | |
1485 | the error. */ | |
1486 | ||
817d9f57 | 1487 | rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey, |
f2de3a33 | 1488 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1489 | tls_ocsp_file, |
1490 | #endif | |
817d9f57 | 1491 | NULL, &server_static_cbinfo); |
059ec3d9 | 1492 | if (rc != OK) return rc; |
817d9f57 | 1493 | cbinfo = server_static_cbinfo; |
059ec3d9 PH |
1494 | |
1495 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers)) | |
1496 | return FAIL; | |
1497 | ||
1498 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
17c76198 PP |
1499 | were historically separated by underscores. So that I can use either form in my |
1500 | tests, and also for general convenience, we turn underscores into hyphens here. | |
1501 | */ | |
059ec3d9 PH |
1502 | |
1503 | if (expciphers != NULL) | |
1504 | { | |
1505 | uschar *s = expciphers; | |
1506 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1507 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1508 | if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) |
7199e1ee | 1509 | return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL); |
7be682ca | 1510 | cbinfo->server_cipher_list = expciphers; |
059ec3d9 PH |
1511 | } |
1512 | ||
1513 | /* If this is a host for which certificate verification is mandatory or | |
1514 | optional, set up appropriately. */ | |
1515 | ||
817d9f57 | 1516 | tls_in.certificate_verified = FALSE; |
53a7196b JH |
1517 | #ifdef EXPERIMENTAL_DANE |
1518 | tls_in.dane_verified = FALSE; | |
1519 | #endif | |
a2ff477a | 1520 | server_verify_callback_called = FALSE; |
059ec3d9 PH |
1521 | |
1522 | if (verify_check_host(&tls_verify_hosts) == OK) | |
1523 | { | |
983207c1 JH |
1524 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
1525 | FALSE, verify_callback_server); | |
059ec3d9 | 1526 | if (rc != OK) return rc; |
a2ff477a | 1527 | server_verify_optional = FALSE; |
059ec3d9 PH |
1528 | } |
1529 | else if (verify_check_host(&tls_try_verify_hosts) == OK) | |
1530 | { | |
983207c1 JH |
1531 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
1532 | TRUE, verify_callback_server); | |
059ec3d9 | 1533 | if (rc != OK) return rc; |
a2ff477a | 1534 | server_verify_optional = TRUE; |
059ec3d9 PH |
1535 | } |
1536 | ||
1537 | /* Prepare for new connection */ | |
1538 | ||
817d9f57 | 1539 | if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL); |
da3ad30d PP |
1540 | |
1541 | /* Warning: we used to SSL_clear(ssl) here, it was removed. | |
1542 | * | |
1543 | * With the SSL_clear(), we get strange interoperability bugs with | |
1544 | * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in | |
1545 | * OpenSSL itself, as a clear should not lead to inability to follow protocols. | |
1546 | * | |
1547 | * The SSL_clear() call is to let an existing SSL* be reused, typically after | |
1548 | * session shutdown. In this case, we have a brand new object and there's no | |
1549 | * obvious reason to immediately clear it. I'm guessing that this was | |
1550 | * originally added because of incomplete initialisation which the clear fixed, | |
1551 | * in some historic release. | |
1552 | */ | |
059ec3d9 PH |
1553 | |
1554 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
1555 | on connection, where outputting anything now upsets the clients and tends to | |
1556 | make them disconnect. We need to have an explicit fflush() here, to force out | |
1557 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
1558 | mode, the fflush() happens when smtp_getc() is called. */ | |
1559 | ||
817d9f57 JH |
1560 | SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1561 | if (!tls_in.on_connect) | |
059ec3d9 PH |
1562 | { |
1563 | smtp_printf("220 TLS go ahead\r\n"); | |
1564 | fflush(smtp_out); | |
1565 | } | |
1566 | ||
1567 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
1568 | that the OpenSSL library doesn't. */ | |
1569 | ||
817d9f57 JH |
1570 | SSL_set_wfd(server_ssl, fileno(smtp_out)); |
1571 | SSL_set_rfd(server_ssl, fileno(smtp_in)); | |
1572 | SSL_set_accept_state(server_ssl); | |
059ec3d9 PH |
1573 | |
1574 | DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); | |
1575 | ||
1576 | sigalrm_seen = FALSE; | |
1577 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 | 1578 | rc = SSL_accept(server_ssl); |
059ec3d9 PH |
1579 | alarm(0); |
1580 | ||
1581 | if (rc <= 0) | |
1582 | { | |
7199e1ee | 1583 | tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL); |
77bb000f PP |
1584 | if (ERR_get_error() == 0) |
1585 | log_write(0, LOG_MAIN, | |
a053d125 | 1586 | "TLS client disconnected cleanly (rejected our certificate?)"); |
059ec3d9 PH |
1587 | return FAIL; |
1588 | } | |
1589 | ||
1590 | DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); | |
1591 | ||
1592 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
1593 | and initialize things. */ | |
1594 | ||
817d9f57 JH |
1595 | construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits); |
1596 | tls_in.cipher = cipherbuf; | |
059ec3d9 PH |
1597 | |
1598 | DEBUG(D_tls) | |
1599 | { | |
1600 | uschar buf[2048]; | |
817d9f57 | 1601 | if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL) |
059ec3d9 PH |
1602 | debug_printf("Shared ciphers: %s\n", buf); |
1603 | } | |
1604 | ||
9d1c15ef JH |
1605 | /* Record the certificate we presented */ |
1606 | { | |
1607 | X509 * crt = SSL_get_certificate(server_ssl); | |
1608 | tls_in.ourcert = crt ? X509_dup(crt) : NULL; | |
1609 | } | |
059ec3d9 | 1610 | |
817d9f57 JH |
1611 | /* Only used by the server-side tls (tls_in), including tls_getc. |
1612 | Client-side (tls_out) reads (seem to?) go via | |
1613 | smtp_read_response()/ip_recv(). | |
1614 | Hence no need to duplicate for _in and _out. | |
1615 | */ | |
059ec3d9 PH |
1616 | ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
1617 | ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; | |
1618 | ssl_xfer_eof = ssl_xfer_error = 0; | |
1619 | ||
1620 | receive_getc = tls_getc; | |
1621 | receive_ungetc = tls_ungetc; | |
1622 | receive_feof = tls_feof; | |
1623 | receive_ferror = tls_ferror; | |
58eb016e | 1624 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 1625 | |
817d9f57 | 1626 | tls_in.active = fileno(smtp_out); |
059ec3d9 PH |
1627 | return OK; |
1628 | } | |
1629 | ||
1630 | ||
1631 | ||
1632 | ||
043b1248 JH |
1633 | static int |
1634 | tls_client_basic_ctx_init(SSL_CTX * ctx, | |
1635 | host_item * host, smtp_transport_options_block * ob | |
1636 | #ifdef EXPERIMENTAL_CERTNAMES | |
1637 | , tls_ext_ctx_cb * cbinfo | |
1638 | #endif | |
1639 | ) | |
1640 | { | |
1641 | int rc; | |
1642 | /* stick to the old behaviour for compatibility if tls_verify_certificates is | |
1643 | set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only | |
1644 | the specified host patterns if one of them is defined */ | |
1645 | ||
1646 | if ((!ob->tls_verify_hosts && !ob->tls_try_verify_hosts) || | |
1647 | (verify_check_host(&ob->tls_verify_hosts) == OK)) | |
1648 | { | |
1649 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
1650 | ob->tls_crl, host, FALSE, verify_callback_client)) != OK) | |
1651 | return rc; | |
1652 | client_verify_optional = FALSE; | |
1653 | ||
1654 | #ifdef EXPERIMENTAL_CERTNAMES | |
1655 | if (ob->tls_verify_cert_hostnames) | |
1656 | { | |
1657 | if (!expand_check(ob->tls_verify_cert_hostnames, | |
1658 | US"tls_verify_cert_hostnames", | |
1659 | &cbinfo->verify_cert_hostnames)) | |
1660 | return FAIL; | |
1661 | if (cbinfo->verify_cert_hostnames) | |
1662 | DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", | |
1663 | cbinfo->verify_cert_hostnames); | |
1664 | } | |
1665 | #endif | |
1666 | } | |
1667 | else if (verify_check_host(&ob->tls_try_verify_hosts) == OK) | |
1668 | { | |
1669 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
1670 | ob->tls_crl, host, TRUE, verify_callback_client)) != OK) | |
1671 | return rc; | |
1672 | client_verify_optional = TRUE; | |
1673 | } | |
1674 | ||
1675 | return OK; | |
1676 | } | |
059ec3d9 | 1677 | |
fde080a4 JH |
1678 | |
1679 | #ifdef EXPERIMENTAL_DANE | |
fde080a4 JH |
1680 | static int |
1681 | dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa) | |
1682 | { | |
1683 | dns_record * rr; | |
1684 | dns_scan dnss; | |
1685 | const char * hostnames[2] = { CS host->name, NULL }; | |
1686 | int found = 0; | |
1687 | ||
1688 | if (DANESSL_init(ssl, NULL, hostnames) != 1) | |
1689 | return tls_error(US"hostnames load", host, NULL); | |
1690 | ||
1691 | for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); | |
1692 | rr; | |
1693 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) | |
1694 | ) if (rr->type == T_TLSA) | |
1695 | { | |
1696 | uschar * p = rr->data; | |
1697 | uint8_t usage, selector, mtype; | |
1698 | const char * mdname; | |
1699 | ||
1700 | found++; | |
1701 | usage = *p++; | |
1702 | selector = *p++; | |
1703 | mtype = *p++; | |
1704 | ||
1705 | switch (mtype) | |
1706 | { | |
1707 | default: | |
1708 | log_write(0, LOG_MAIN, | |
1709 | "DANE error: TLSA record w/bad mtype 0x%x", mtype); | |
1710 | return FAIL; | |
1711 | case 0: mdname = NULL; break; | |
1712 | case 1: mdname = "sha256"; break; | |
1713 | case 2: mdname = "sha512"; break; | |
1714 | } | |
1715 | ||
1716 | switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3)) | |
1717 | { | |
1718 | default: | |
1719 | case 0: /* action not taken */ | |
1720 | return tls_error(US"tlsa load", host, NULL); | |
1721 | case 1: break; | |
1722 | } | |
594706ea JH |
1723 | |
1724 | tls_out.tlsa_usage |= 1<<usage; | |
fde080a4 JH |
1725 | } |
1726 | ||
1727 | if (found) | |
1728 | return OK; | |
1729 | ||
1730 | log_write(0, LOG_MAIN, "DANE error: No TLSA records"); | |
1731 | return FAIL; | |
1732 | } | |
1733 | #endif /*EXPERIMENTAL_DANE*/ | |
1734 | ||
1735 | ||
1736 | ||
059ec3d9 PH |
1737 | /************************************************* |
1738 | * Start a TLS session in a client * | |
1739 | *************************************************/ | |
1740 | ||
1741 | /* Called from the smtp transport after STARTTLS has been accepted. | |
1742 | ||
1743 | Argument: | |
1744 | fd the fd of the connection | |
1745 | host connected host (for messages) | |
83da1223 | 1746 | addr the first address |
a7538db1 | 1747 | tb transport (always smtp) |
0e66b3b6 | 1748 | tlsa_dnsa tlsa lookup, if DANE, else null |
059ec3d9 PH |
1749 | |
1750 | Returns: OK on success | |
1751 | FAIL otherwise - note that tls_error() will not give DEFER | |
1752 | because this is not a server | |
1753 | */ | |
1754 | ||
1755 | int | |
f5d78688 | 1756 | tls_client_start(int fd, host_item *host, address_item *addr, |
0e66b3b6 JH |
1757 | transport_instance *tb |
1758 | #ifdef EXPERIMENTAL_DANE | |
1759 | , dns_answer * tlsa_dnsa | |
1760 | #endif | |
1761 | ) | |
059ec3d9 | 1762 | { |
a7538db1 JH |
1763 | smtp_transport_options_block * ob = |
1764 | (smtp_transport_options_block *)tb->options_block; | |
059ec3d9 | 1765 | static uschar txt[256]; |
868f5672 JH |
1766 | uschar * expciphers; |
1767 | X509 * server_cert; | |
059ec3d9 | 1768 | int rc; |
817d9f57 | 1769 | static uschar cipherbuf[256]; |
043b1248 JH |
1770 | |
1771 | #ifndef DISABLE_OCSP | |
043b1248 | 1772 | BOOL request_ocsp = FALSE; |
6634ac8d | 1773 | BOOL require_ocsp = FALSE; |
043b1248 | 1774 | #endif |
043b1248 JH |
1775 | |
1776 | #ifdef EXPERIMENTAL_DANE | |
594706ea | 1777 | tls_out.tlsa_usage = 0; |
043b1248 JH |
1778 | #endif |
1779 | ||
f2de3a33 | 1780 | #ifndef DISABLE_OCSP |
043b1248 | 1781 | { |
fca41d5a JH |
1782 | if ((require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp, |
1783 | NULL, host->name, host->address, NULL) == OK)) | |
1784 | request_ocsp = TRUE; | |
1785 | else | |
1786 | { | |
1787 | # ifdef EXPERIMENTAL_DANE | |
0e66b3b6 | 1788 | if ( tlsa_dnsa |
fca41d5a JH |
1789 | && ob->hosts_request_ocsp[0] == '*' |
1790 | && ob->hosts_request_ocsp[1] == '\0' | |
1791 | ) | |
1792 | { | |
1793 | /* Unchanged from default. Use a safer one under DANE */ | |
1794 | request_ocsp = TRUE; | |
1795 | ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} " | |
1796 | " {= {4}{$tls_out_tlsa_usage}} } " | |
1797 | " {*}{}}"; | |
1798 | } | |
1799 | else | |
1800 | # endif | |
1801 | request_ocsp = verify_check_this_host(&ob->hosts_request_ocsp, | |
1802 | NULL, host->name, host->address, NULL) == OK; | |
1803 | } | |
043b1248 | 1804 | } |
f5d78688 | 1805 | #endif |
059ec3d9 | 1806 | |
65867078 JH |
1807 | rc = tls_init(&client_ctx, host, NULL, |
1808 | ob->tls_certificate, ob->tls_privatekey, | |
f2de3a33 | 1809 | #ifndef DISABLE_OCSP |
44662487 | 1810 | (void *)(long)request_ocsp, |
3f7eeb86 | 1811 | #endif |
817d9f57 | 1812 | addr, &client_static_cbinfo); |
059ec3d9 PH |
1813 | if (rc != OK) return rc; |
1814 | ||
817d9f57 | 1815 | tls_out.certificate_verified = FALSE; |
a2ff477a | 1816 | client_verify_callback_called = FALSE; |
059ec3d9 | 1817 | |
65867078 JH |
1818 | if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers", |
1819 | &expciphers)) | |
059ec3d9 PH |
1820 | return FAIL; |
1821 | ||
1822 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
1823 | are separated by underscores. So that I can use either form in my tests, and | |
1824 | also for general convenience, we turn underscores into hyphens here. */ | |
1825 | ||
1826 | if (expciphers != NULL) | |
1827 | { | |
1828 | uschar *s = expciphers; | |
1829 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1830 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1831 | if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers)) |
7199e1ee | 1832 | return tls_error(US"SSL_CTX_set_cipher_list", host, NULL); |
059ec3d9 PH |
1833 | } |
1834 | ||
043b1248 | 1835 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 | 1836 | if (tlsa_dnsa) |
a63be306 | 1837 | { |
e5cccda9 JH |
1838 | SSL_CTX_set_verify(client_ctx, SSL_VERIFY_PEER, verify_callback_client_dane); |
1839 | ||
043b1248 | 1840 | if (!DANESSL_library_init()) |
b4161d10 | 1841 | return tls_error(US"library init", host, NULL); |
043b1248 | 1842 | if (DANESSL_CTX_init(client_ctx) <= 0) |
b4161d10 | 1843 | return tls_error(US"context init", host, NULL); |
043b1248 JH |
1844 | } |
1845 | else | |
e51c7be2 | 1846 | |
043b1248 JH |
1847 | #endif |
1848 | ||
1849 | if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob | |
e51c7be2 | 1850 | #ifdef EXPERIMENTAL_CERTNAMES |
043b1248 | 1851 | , client_static_cbinfo |
e51c7be2 | 1852 | #endif |
043b1248 | 1853 | )) != OK) |
65867078 | 1854 | return rc; |
059ec3d9 | 1855 | |
65867078 JH |
1856 | if ((client_ssl = SSL_new(client_ctx)) == NULL) |
1857 | return tls_error(US"SSL_new", host, NULL); | |
817d9f57 JH |
1858 | SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1859 | SSL_set_fd(client_ssl, fd); | |
1860 | SSL_set_connect_state(client_ssl); | |
059ec3d9 | 1861 | |
65867078 | 1862 | if (ob->tls_sni) |
3f0945ff | 1863 | { |
65867078 | 1864 | if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni)) |
3f0945ff | 1865 | return FAIL; |
ec4b68e5 | 1866 | if (tls_out.sni == NULL) |
2c9a0e86 PP |
1867 | { |
1868 | DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n"); | |
1869 | } | |
ec4b68e5 | 1870 | else if (!Ustrlen(tls_out.sni)) |
817d9f57 | 1871 | tls_out.sni = NULL; |
3f0945ff PP |
1872 | else |
1873 | { | |
35731706 | 1874 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 JH |
1875 | DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni); |
1876 | SSL_set_tlsext_host_name(client_ssl, tls_out.sni); | |
35731706 PP |
1877 | #else |
1878 | DEBUG(D_tls) | |
1879 | debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n", | |
02d9264f | 1880 | tls_out.sni); |
35731706 | 1881 | #endif |
3f0945ff PP |
1882 | } |
1883 | } | |
1884 | ||
594706ea | 1885 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 JH |
1886 | if (tlsa_dnsa) |
1887 | if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa)) != OK) | |
594706ea JH |
1888 | return rc; |
1889 | #endif | |
1890 | ||
f2de3a33 | 1891 | #ifndef DISABLE_OCSP |
f5d78688 JH |
1892 | /* Request certificate status at connection-time. If the server |
1893 | does OCSP stapling we will get the callback (set in tls_init()) */ | |
b50c8b84 | 1894 | # ifdef EXPERIMENTAL_DANE |
594706ea JH |
1895 | if (request_ocsp) |
1896 | { | |
1897 | const uschar * s; | |
1898 | if ( (s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage") | |
1899 | || (s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage") | |
1900 | ) | |
1901 | { /* Re-eval now $tls_out_tlsa_usage is populated. If | |
1902 | this means we avoid the OCSP request, we wasted the setup | |
1903 | cost in tls_init(). */ | |
1904 | require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp, | |
1905 | NULL, host->name, host->address, NULL) == OK; | |
1906 | request_ocsp = require_ocsp ? TRUE | |
1907 | : verify_check_this_host(&ob->hosts_request_ocsp, | |
1908 | NULL, host->name, host->address, NULL) == OK; | |
1909 | } | |
1910 | } | |
b50c8b84 JH |
1911 | # endif |
1912 | ||
44662487 JH |
1913 | if (request_ocsp) |
1914 | { | |
f5d78688 | 1915 | SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp); |
44662487 JH |
1916 | client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp; |
1917 | tls_out.ocsp = OCSP_NOT_RESP; | |
1918 | } | |
f5d78688 JH |
1919 | #endif |
1920 | ||
a7538db1 JH |
1921 | #ifdef EXPERIMENTAL_TPDA |
1922 | client_static_cbinfo->event_action = tb->tpda_event_action; | |
1923 | #endif | |
043b1248 | 1924 | |
059ec3d9 PH |
1925 | /* There doesn't seem to be a built-in timeout on connection. */ |
1926 | ||
1927 | DEBUG(D_tls) debug_printf("Calling SSL_connect\n"); | |
1928 | sigalrm_seen = FALSE; | |
65867078 | 1929 | alarm(ob->command_timeout); |
817d9f57 | 1930 | rc = SSL_connect(client_ssl); |
059ec3d9 PH |
1931 | alarm(0); |
1932 | ||
043b1248 | 1933 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 | 1934 | if (tlsa_dnsa) |
fde080a4 | 1935 | DANESSL_cleanup(client_ssl); |
043b1248 JH |
1936 | #endif |
1937 | ||
059ec3d9 | 1938 | if (rc <= 0) |
7199e1ee | 1939 | return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL); |
059ec3d9 PH |
1940 | |
1941 | DEBUG(D_tls) debug_printf("SSL_connect succeeded\n"); | |
1942 | ||
453a6645 | 1943 | /* Beware anonymous ciphers which lead to server_cert being NULL */ |
9d1c15ef | 1944 | /*XXX server_cert is never freed... use X509_free() */ |
817d9f57 | 1945 | server_cert = SSL_get_peer_certificate (client_ssl); |
453a6645 PP |
1946 | if (server_cert) |
1947 | { | |
817d9f57 | 1948 | tls_out.peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert), |
453a6645 | 1949 | CS txt, sizeof(txt)); |
9d1c15ef | 1950 | tls_out.peerdn = txt; /*XXX a static buffer... */ |
453a6645 PP |
1951 | } |
1952 | else | |
817d9f57 | 1953 | tls_out.peerdn = NULL; |
059ec3d9 | 1954 | |
817d9f57 JH |
1955 | construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits); |
1956 | tls_out.cipher = cipherbuf; | |
059ec3d9 | 1957 | |
9d1c15ef JH |
1958 | /* Record the certificate we presented */ |
1959 | { | |
1960 | X509 * crt = SSL_get_certificate(client_ssl); | |
1961 | tls_out.ourcert = crt ? X509_dup(crt) : NULL; | |
1962 | } | |
1963 | ||
817d9f57 | 1964 | tls_out.active = fd; |
059ec3d9 PH |
1965 | return OK; |
1966 | } | |
1967 | ||
1968 | ||
1969 | ||
1970 | ||
1971 | ||
1972 | /************************************************* | |
1973 | * TLS version of getc * | |
1974 | *************************************************/ | |
1975 | ||
1976 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
1977 | it refills the buffer via the SSL reading function. | |
1978 | ||
1979 | Arguments: none | |
1980 | Returns: the next character or EOF | |
817d9f57 JH |
1981 | |
1982 | Only used by the server-side TLS. | |
059ec3d9 PH |
1983 | */ |
1984 | ||
1985 | int | |
1986 | tls_getc(void) | |
1987 | { | |
1988 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) | |
1989 | { | |
1990 | int error; | |
1991 | int inbytes; | |
1992 | ||
817d9f57 | 1993 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl, |
c80c5570 | 1994 | ssl_xfer_buffer, ssl_xfer_buffer_size); |
059ec3d9 PH |
1995 | |
1996 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 JH |
1997 | inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size); |
1998 | error = SSL_get_error(server_ssl, inbytes); | |
059ec3d9 PH |
1999 | alarm(0); |
2000 | ||
2001 | /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been | |
2002 | closed down, not that the socket itself has been closed down. Revert to | |
2003 | non-SSL handling. */ | |
2004 | ||
2005 | if (error == SSL_ERROR_ZERO_RETURN) | |
2006 | { | |
2007 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2008 | ||
2009 | receive_getc = smtp_getc; | |
2010 | receive_ungetc = smtp_ungetc; | |
2011 | receive_feof = smtp_feof; | |
2012 | receive_ferror = smtp_ferror; | |
58eb016e | 2013 | receive_smtp_buffered = smtp_buffered; |
059ec3d9 | 2014 | |
817d9f57 JH |
2015 | SSL_free(server_ssl); |
2016 | server_ssl = NULL; | |
2017 | tls_in.active = -1; | |
2018 | tls_in.bits = 0; | |
2019 | tls_in.cipher = NULL; | |
2020 | tls_in.peerdn = NULL; | |
2021 | tls_in.sni = NULL; | |
059ec3d9 PH |
2022 | |
2023 | return smtp_getc(); | |
2024 | } | |
2025 | ||
2026 | /* Handle genuine errors */ | |
2027 | ||
ba084640 PP |
2028 | else if (error == SSL_ERROR_SSL) |
2029 | { | |
2030 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
89dd51cd | 2031 | log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); |
ba084640 PP |
2032 | ssl_xfer_error = 1; |
2033 | return EOF; | |
2034 | } | |
2035 | ||
059ec3d9 PH |
2036 | else if (error != SSL_ERROR_NONE) |
2037 | { | |
2038 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
2039 | ssl_xfer_error = 1; | |
2040 | return EOF; | |
2041 | } | |
c80c5570 | 2042 | |
80a47a2c TK |
2043 | #ifndef DISABLE_DKIM |
2044 | dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); | |
2045 | #endif | |
059ec3d9 PH |
2046 | ssl_xfer_buffer_hwm = inbytes; |
2047 | ssl_xfer_buffer_lwm = 0; | |
2048 | } | |
2049 | ||
2050 | /* Something in the buffer; return next uschar */ | |
2051 | ||
2052 | return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; | |
2053 | } | |
2054 | ||
2055 | ||
2056 | ||
2057 | /************************************************* | |
2058 | * Read bytes from TLS channel * | |
2059 | *************************************************/ | |
2060 | ||
2061 | /* | |
2062 | Arguments: | |
2063 | buff buffer of data | |
2064 | len size of buffer | |
2065 | ||
2066 | Returns: the number of bytes read | |
2067 | -1 after a failed read | |
817d9f57 JH |
2068 | |
2069 | Only used by the client-side TLS. | |
059ec3d9 PH |
2070 | */ |
2071 | ||
2072 | int | |
389ca47a | 2073 | tls_read(BOOL is_server, uschar *buff, size_t len) |
059ec3d9 | 2074 | { |
389ca47a | 2075 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 PH |
2076 | int inbytes; |
2077 | int error; | |
2078 | ||
389ca47a | 2079 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl, |
c80c5570 | 2080 | buff, (unsigned int)len); |
059ec3d9 | 2081 | |
389ca47a JH |
2082 | inbytes = SSL_read(ssl, CS buff, len); |
2083 | error = SSL_get_error(ssl, inbytes); | |
059ec3d9 PH |
2084 | |
2085 | if (error == SSL_ERROR_ZERO_RETURN) | |
2086 | { | |
2087 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2088 | return -1; | |
2089 | } | |
2090 | else if (error != SSL_ERROR_NONE) | |
2091 | { | |
2092 | return -1; | |
2093 | } | |
2094 | ||
2095 | return inbytes; | |
2096 | } | |
2097 | ||
2098 | ||
2099 | ||
2100 | ||
2101 | ||
2102 | /************************************************* | |
2103 | * Write bytes down TLS channel * | |
2104 | *************************************************/ | |
2105 | ||
2106 | /* | |
2107 | Arguments: | |
817d9f57 | 2108 | is_server channel specifier |
059ec3d9 PH |
2109 | buff buffer of data |
2110 | len number of bytes | |
2111 | ||
2112 | Returns: the number of bytes after a successful write, | |
2113 | -1 after a failed write | |
817d9f57 JH |
2114 | |
2115 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2116 | */ |
2117 | ||
2118 | int | |
817d9f57 | 2119 | tls_write(BOOL is_server, const uschar *buff, size_t len) |
059ec3d9 PH |
2120 | { |
2121 | int outbytes; | |
2122 | int error; | |
2123 | int left = len; | |
817d9f57 | 2124 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 | 2125 | |
c80c5570 | 2126 | DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left); |
059ec3d9 PH |
2127 | while (left > 0) |
2128 | { | |
c80c5570 | 2129 | DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left); |
059ec3d9 PH |
2130 | outbytes = SSL_write(ssl, CS buff, left); |
2131 | error = SSL_get_error(ssl, outbytes); | |
2132 | DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error); | |
2133 | switch (error) | |
2134 | { | |
2135 | case SSL_ERROR_SSL: | |
2136 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2137 | log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); | |
2138 | return -1; | |
2139 | ||
2140 | case SSL_ERROR_NONE: | |
2141 | left -= outbytes; | |
2142 | buff += outbytes; | |
2143 | break; | |
2144 | ||
2145 | case SSL_ERROR_ZERO_RETURN: | |
2146 | log_write(0, LOG_MAIN, "SSL channel closed on write"); | |
2147 | return -1; | |
2148 | ||
817d9f57 JH |
2149 | case SSL_ERROR_SYSCALL: |
2150 | log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", | |
2151 | sender_fullhost ? sender_fullhost : US"<unknown>", | |
2152 | strerror(errno)); | |
2153 | ||
059ec3d9 PH |
2154 | default: |
2155 | log_write(0, LOG_MAIN, "SSL_write error %d", error); | |
2156 | return -1; | |
2157 | } | |
2158 | } | |
2159 | return len; | |
2160 | } | |
2161 | ||
2162 | ||
2163 | ||
2164 | /************************************************* | |
2165 | * Close down a TLS session * | |
2166 | *************************************************/ | |
2167 | ||
2168 | /* This is also called from within a delivery subprocess forked from the | |
2169 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
2170 | would tamper with the SSL session in the parent process). | |
2171 | ||
2172 | Arguments: TRUE if SSL_shutdown is to be called | |
2173 | Returns: nothing | |
817d9f57 JH |
2174 | |
2175 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2176 | */ |
2177 | ||
2178 | void | |
817d9f57 | 2179 | tls_close(BOOL is_server, BOOL shutdown) |
059ec3d9 | 2180 | { |
817d9f57 | 2181 | SSL **sslp = is_server ? &server_ssl : &client_ssl; |
389ca47a | 2182 | int *fdp = is_server ? &tls_in.active : &tls_out.active; |
817d9f57 JH |
2183 | |
2184 | if (*fdp < 0) return; /* TLS was not active */ | |
059ec3d9 PH |
2185 | |
2186 | if (shutdown) | |
2187 | { | |
2188 | DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n"); | |
817d9f57 | 2189 | SSL_shutdown(*sslp); |
059ec3d9 PH |
2190 | } |
2191 | ||
817d9f57 JH |
2192 | SSL_free(*sslp); |
2193 | *sslp = NULL; | |
059ec3d9 | 2194 | |
817d9f57 | 2195 | *fdp = -1; |
059ec3d9 PH |
2196 | } |
2197 | ||
36f12725 NM |
2198 | |
2199 | ||
2200 | ||
3375e053 PP |
2201 | /************************************************* |
2202 | * Let tls_require_ciphers be checked at startup * | |
2203 | *************************************************/ | |
2204 | ||
2205 | /* The tls_require_ciphers option, if set, must be something which the | |
2206 | library can parse. | |
2207 | ||
2208 | Returns: NULL on success, or error message | |
2209 | */ | |
2210 | ||
2211 | uschar * | |
2212 | tls_validate_require_cipher(void) | |
2213 | { | |
2214 | SSL_CTX *ctx; | |
2215 | uschar *s, *expciphers, *err; | |
2216 | ||
2217 | /* this duplicates from tls_init(), we need a better "init just global | |
2218 | state, for no specific purpose" singleton function of our own */ | |
2219 | ||
2220 | SSL_load_error_strings(); | |
2221 | OpenSSL_add_ssl_algorithms(); | |
2222 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
2223 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the | |
2224 | list of available digests. */ | |
2225 | EVP_add_digest(EVP_sha256()); | |
2226 | #endif | |
2227 | ||
2228 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
2229 | return NULL; | |
2230 | ||
2231 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers)) | |
2232 | return US"failed to expand tls_require_ciphers"; | |
2233 | ||
2234 | if (!(expciphers && *expciphers)) | |
2235 | return NULL; | |
2236 | ||
2237 | /* normalisation ripped from above */ | |
2238 | s = expciphers; | |
2239 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
2240 | ||
2241 | err = NULL; | |
2242 | ||
2243 | ctx = SSL_CTX_new(SSLv23_server_method()); | |
2244 | if (!ctx) | |
2245 | { | |
2246 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2247 | return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring); | |
2248 | } | |
2249 | ||
2250 | DEBUG(D_tls) | |
2251 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
2252 | ||
2253 | if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) | |
2254 | { | |
2255 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2256 | err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers); | |
2257 | } | |
2258 | ||
2259 | SSL_CTX_free(ctx); | |
2260 | ||
2261 | return err; | |
2262 | } | |
2263 | ||
2264 | ||
2265 | ||
2266 | ||
36f12725 NM |
2267 | /************************************************* |
2268 | * Report the library versions. * | |
2269 | *************************************************/ | |
2270 | ||
2271 | /* There have historically been some issues with binary compatibility in | |
2272 | OpenSSL libraries; if Exim (like many other applications) is built against | |
2273 | one version of OpenSSL but the run-time linker picks up another version, | |
2274 | it can result in serious failures, including crashing with a SIGSEGV. So | |
2275 | report the version found by the compiler and the run-time version. | |
2276 | ||
f64a1e23 PP |
2277 | Note: some OS vendors backport security fixes without changing the version |
2278 | number/string, and the version date remains unchanged. The _build_ date | |
2279 | will change, so we can more usefully assist with version diagnosis by also | |
2280 | reporting the build date. | |
2281 | ||
36f12725 NM |
2282 | Arguments: a FILE* to print the results to |
2283 | Returns: nothing | |
2284 | */ | |
2285 | ||
2286 | void | |
2287 | tls_version_report(FILE *f) | |
2288 | { | |
754a0503 | 2289 | fprintf(f, "Library version: OpenSSL: Compile: %s\n" |
f64a1e23 PP |
2290 | " Runtime: %s\n" |
2291 | " : %s\n", | |
754a0503 | 2292 | OPENSSL_VERSION_TEXT, |
f64a1e23 PP |
2293 | SSLeay_version(SSLEAY_VERSION), |
2294 | SSLeay_version(SSLEAY_BUILT_ON)); | |
2295 | /* third line is 38 characters for the %s and the line is 73 chars long; | |
2296 | the OpenSSL output includes a "built on: " prefix already. */ | |
36f12725 NM |
2297 | } |
2298 | ||
9e3331ea TK |
2299 | |
2300 | ||
2301 | ||
2302 | /************************************************* | |
17c76198 | 2303 | * Random number generation * |
9e3331ea TK |
2304 | *************************************************/ |
2305 | ||
2306 | /* Pseudo-random number generation. The result is not expected to be | |
2307 | cryptographically strong but not so weak that someone will shoot themselves | |
2308 | in the foot using it as a nonce in input in some email header scheme or | |
2309 | whatever weirdness they'll twist this into. The result should handle fork() | |
2310 | and avoid repeating sequences. OpenSSL handles that for us. | |
2311 | ||
2312 | Arguments: | |
2313 | max range maximum | |
2314 | Returns a random number in range [0, max-1] | |
2315 | */ | |
2316 | ||
2317 | int | |
17c76198 | 2318 | vaguely_random_number(int max) |
9e3331ea TK |
2319 | { |
2320 | unsigned int r; | |
2321 | int i, needed_len; | |
de6135a0 PP |
2322 | static pid_t pidlast = 0; |
2323 | pid_t pidnow; | |
9e3331ea TK |
2324 | uschar *p; |
2325 | uschar smallbuf[sizeof(r)]; | |
2326 | ||
2327 | if (max <= 1) | |
2328 | return 0; | |
2329 | ||
de6135a0 PP |
2330 | pidnow = getpid(); |
2331 | if (pidnow != pidlast) | |
2332 | { | |
2333 | /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state | |
2334 | is unique for each thread", this doesn't apparently apply across processes, | |
2335 | so our own warning from vaguely_random_number_fallback() applies here too. | |
2336 | Fix per PostgreSQL. */ | |
2337 | if (pidlast != 0) | |
2338 | RAND_cleanup(); | |
2339 | pidlast = pidnow; | |
2340 | } | |
2341 | ||
9e3331ea TK |
2342 | /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ |
2343 | if (!RAND_status()) | |
2344 | { | |
2345 | randstuff r; | |
2346 | gettimeofday(&r.tv, NULL); | |
2347 | r.p = getpid(); | |
2348 | ||
2349 | RAND_seed((uschar *)(&r), sizeof(r)); | |
2350 | } | |
2351 | /* We're after pseudo-random, not random; if we still don't have enough data | |
2352 | in the internal PRNG then our options are limited. We could sleep and hope | |
2353 | for entropy to come along (prayer technique) but if the system is so depleted | |
2354 | in the first place then something is likely to just keep taking it. Instead, | |
2355 | we'll just take whatever little bit of pseudo-random we can still manage to | |
2356 | get. */ | |
2357 | ||
2358 | needed_len = sizeof(r); | |
2359 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
2360 | asked for a number less than 10. */ | |
2361 | for (r = max, i = 0; r; ++i) | |
2362 | r >>= 1; | |
2363 | i = (i + 7) / 8; | |
2364 | if (i < needed_len) | |
2365 | needed_len = i; | |
2366 | ||
2367 | /* We do not care if crypto-strong */ | |
17c76198 PP |
2368 | i = RAND_pseudo_bytes(smallbuf, needed_len); |
2369 | if (i < 0) | |
2370 | { | |
2371 | DEBUG(D_all) | |
2372 | debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n"); | |
2373 | return vaguely_random_number_fallback(max); | |
2374 | } | |
2375 | ||
9e3331ea TK |
2376 | r = 0; |
2377 | for (p = smallbuf; needed_len; --needed_len, ++p) | |
2378 | { | |
2379 | r *= 256; | |
2380 | r += *p; | |
2381 | } | |
2382 | ||
2383 | /* We don't particularly care about weighted results; if someone wants | |
2384 | smooth distribution and cares enough then they should submit a patch then. */ | |
2385 | return r % max; | |
2386 | } | |
2387 | ||
77bb000f PP |
2388 | |
2389 | ||
2390 | ||
2391 | /************************************************* | |
2392 | * OpenSSL option parse * | |
2393 | *************************************************/ | |
2394 | ||
2395 | /* Parse one option for tls_openssl_options_parse below | |
2396 | ||
2397 | Arguments: | |
2398 | name one option name | |
2399 | value place to store a value for it | |
2400 | Returns success or failure in parsing | |
2401 | */ | |
2402 | ||
2403 | struct exim_openssl_option { | |
2404 | uschar *name; | |
2405 | long value; | |
2406 | }; | |
2407 | /* We could use a macro to expand, but we need the ifdef and not all the | |
2408 | options document which version they were introduced in. Policylet: include | |
2409 | all options unless explicitly for DTLS, let the administrator choose which | |
2410 | to apply. | |
2411 | ||
2412 | This list is current as of: | |
e2fbf4a2 PP |
2413 | ==> 1.0.1b <== |
2414 | Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev | |
2415 | */ | |
77bb000f PP |
2416 | static struct exim_openssl_option exim_openssl_options[] = { |
2417 | /* KEEP SORTED ALPHABETICALLY! */ | |
2418 | #ifdef SSL_OP_ALL | |
73a46702 | 2419 | { US"all", SSL_OP_ALL }, |
77bb000f PP |
2420 | #endif |
2421 | #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION | |
73a46702 | 2422 | { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, |
77bb000f PP |
2423 | #endif |
2424 | #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE | |
73a46702 | 2425 | { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, |
77bb000f PP |
2426 | #endif |
2427 | #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS | |
73a46702 | 2428 | { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, |
77bb000f PP |
2429 | #endif |
2430 | #ifdef SSL_OP_EPHEMERAL_RSA | |
73a46702 | 2431 | { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, |
77bb000f PP |
2432 | #endif |
2433 | #ifdef SSL_OP_LEGACY_SERVER_CONNECT | |
73a46702 | 2434 | { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, |
77bb000f PP |
2435 | #endif |
2436 | #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER | |
73a46702 | 2437 | { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, |
77bb000f PP |
2438 | #endif |
2439 | #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG | |
73a46702 | 2440 | { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, |
77bb000f PP |
2441 | #endif |
2442 | #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING | |
73a46702 | 2443 | { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, |
77bb000f PP |
2444 | #endif |
2445 | #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG | |
73a46702 | 2446 | { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, |
77bb000f PP |
2447 | #endif |
2448 | #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG | |
73a46702 | 2449 | { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, |
77bb000f | 2450 | #endif |
c80c5570 PP |
2451 | #ifdef SSL_OP_NO_COMPRESSION |
2452 | { US"no_compression", SSL_OP_NO_COMPRESSION }, | |
2453 | #endif | |
77bb000f | 2454 | #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |
73a46702 | 2455 | { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, |
77bb000f | 2456 | #endif |
c0c7b2da PP |
2457 | #ifdef SSL_OP_NO_SSLv2 |
2458 | { US"no_sslv2", SSL_OP_NO_SSLv2 }, | |
2459 | #endif | |
2460 | #ifdef SSL_OP_NO_SSLv3 | |
2461 | { US"no_sslv3", SSL_OP_NO_SSLv3 }, | |
2462 | #endif | |
2463 | #ifdef SSL_OP_NO_TICKET | |
2464 | { US"no_ticket", SSL_OP_NO_TICKET }, | |
2465 | #endif | |
2466 | #ifdef SSL_OP_NO_TLSv1 | |
2467 | { US"no_tlsv1", SSL_OP_NO_TLSv1 }, | |
2468 | #endif | |
c80c5570 PP |
2469 | #ifdef SSL_OP_NO_TLSv1_1 |
2470 | #if SSL_OP_NO_TLSv1_1 == 0x00000400L | |
2471 | /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */ | |
2472 | #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring | |
2473 | #else | |
2474 | { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 }, | |
2475 | #endif | |
2476 | #endif | |
2477 | #ifdef SSL_OP_NO_TLSv1_2 | |
2478 | { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 }, | |
2479 | #endif | |
e2fbf4a2 PP |
2480 | #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG |
2481 | { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG }, | |
2482 | #endif | |
77bb000f | 2483 | #ifdef SSL_OP_SINGLE_DH_USE |
73a46702 | 2484 | { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, |
77bb000f PP |
2485 | #endif |
2486 | #ifdef SSL_OP_SINGLE_ECDH_USE | |
73a46702 | 2487 | { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, |
77bb000f PP |
2488 | #endif |
2489 | #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG | |
73a46702 | 2490 | { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, |
77bb000f PP |
2491 | #endif |
2492 | #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG | |
73a46702 | 2493 | { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, |
77bb000f PP |
2494 | #endif |
2495 | #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG | |
73a46702 | 2496 | { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, |
77bb000f PP |
2497 | #endif |
2498 | #ifdef SSL_OP_TLS_D5_BUG | |
73a46702 | 2499 | { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, |
77bb000f PP |
2500 | #endif |
2501 | #ifdef SSL_OP_TLS_ROLLBACK_BUG | |
73a46702 | 2502 | { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, |
77bb000f PP |
2503 | #endif |
2504 | }; | |
2505 | static int exim_openssl_options_size = | |
2506 | sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option); | |
2507 | ||
c80c5570 | 2508 | |
77bb000f PP |
2509 | static BOOL |
2510 | tls_openssl_one_option_parse(uschar *name, long *value) | |
2511 | { | |
2512 | int first = 0; | |
2513 | int last = exim_openssl_options_size; | |
2514 | while (last > first) | |
2515 | { | |
2516 | int middle = (first + last)/2; | |
2517 | int c = Ustrcmp(name, exim_openssl_options[middle].name); | |
2518 | if (c == 0) | |
2519 | { | |
2520 | *value = exim_openssl_options[middle].value; | |
2521 | return TRUE; | |
2522 | } | |
2523 | else if (c > 0) | |
2524 | first = middle + 1; | |
2525 | else | |
2526 | last = middle; | |
2527 | } | |
2528 | return FALSE; | |
2529 | } | |
2530 | ||
2531 | ||
2532 | ||
2533 | ||
2534 | /************************************************* | |
2535 | * OpenSSL option parsing logic * | |
2536 | *************************************************/ | |
2537 | ||
2538 | /* OpenSSL has a number of compatibility options which an administrator might | |
2539 | reasonably wish to set. Interpret a list similarly to decode_bits(), so that | |
2540 | we look like log_selector. | |
2541 | ||
2542 | Arguments: | |
2543 | option_spec the administrator-supplied string of options | |
2544 | results ptr to long storage for the options bitmap | |
2545 | Returns success or failure | |
2546 | */ | |
2547 | ||
2548 | BOOL | |
2549 | tls_openssl_options_parse(uschar *option_spec, long *results) | |
2550 | { | |
2551 | long result, item; | |
2552 | uschar *s, *end; | |
2553 | uschar keep_c; | |
2554 | BOOL adding, item_parsed; | |
2555 | ||
0e944a0d | 2556 | result = 0L; |
b1770b6e | 2557 | /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed |
da3ad30d | 2558 | * from default because it increases BEAST susceptibility. */ |
f0f5a555 PP |
2559 | #ifdef SSL_OP_NO_SSLv2 |
2560 | result |= SSL_OP_NO_SSLv2; | |
2561 | #endif | |
77bb000f PP |
2562 | |
2563 | if (option_spec == NULL) | |
2564 | { | |
2565 | *results = result; | |
2566 | return TRUE; | |
2567 | } | |
2568 | ||
2569 | for (s=option_spec; *s != '\0'; /**/) | |
2570 | { | |
2571 | while (isspace(*s)) ++s; | |
2572 | if (*s == '\0') | |
2573 | break; | |
2574 | if (*s != '+' && *s != '-') | |
2575 | { | |
2576 | DEBUG(D_tls) debug_printf("malformed openssl option setting: " | |
0e944a0d | 2577 | "+ or - expected but found \"%s\"\n", s); |
77bb000f PP |
2578 | return FALSE; |
2579 | } | |
2580 | adding = *s++ == '+'; | |
2581 | for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; | |
2582 | keep_c = *end; | |
2583 | *end = '\0'; | |
2584 | item_parsed = tls_openssl_one_option_parse(s, &item); | |
2585 | if (!item_parsed) | |
2586 | { | |
0e944a0d | 2587 | DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); |
77bb000f PP |
2588 | return FALSE; |
2589 | } | |
2590 | DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n", | |
2591 | adding ? "adding" : "removing", result, item, s); | |
2592 | if (adding) | |
2593 | result |= item; | |
2594 | else | |
2595 | result &= ~item; | |
2596 | *end = keep_c; | |
2597 | s = end; | |
2598 | } | |
2599 | ||
2600 | *results = result; | |
2601 | return TRUE; | |
2602 | } | |
2603 | ||
9d1c15ef JH |
2604 | /* vi: aw ai sw=2 |
2605 | */ | |
059ec3d9 | 2606 | /* End of tls-openssl.c */ |