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]; | |
440 | ||
441 | X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt)); | |
442 | ||
443 | DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s\n", txt); | |
444 | tls_out.peerdn = txt; | |
445 | tls_out.peercert = X509_dup(cert); | |
446 | ||
447 | if (state == 1) | |
53a7196b | 448 | tls_out.dane_verified = |
e5cccda9 JH |
449 | tls_out.certificate_verified = TRUE; |
450 | return 1; | |
451 | } | |
53a7196b JH |
452 | |
453 | #endif /*EXPERIMENTAL_DANE*/ | |
e5cccda9 | 454 | |
059ec3d9 PH |
455 | |
456 | /************************************************* | |
457 | * Information callback * | |
458 | *************************************************/ | |
459 | ||
460 | /* The SSL library functions call this from time to time to indicate what they | |
7be682ca PP |
461 | are doing. We copy the string to the debugging output when TLS debugging has |
462 | been requested. | |
059ec3d9 PH |
463 | |
464 | Arguments: | |
465 | s the SSL connection | |
466 | where | |
467 | ret | |
468 | ||
469 | Returns: nothing | |
470 | */ | |
471 | ||
472 | static void | |
473 | info_callback(SSL *s, int where, int ret) | |
474 | { | |
475 | where = where; | |
476 | ret = ret; | |
477 | DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s)); | |
478 | } | |
479 | ||
480 | ||
481 | ||
482 | /************************************************* | |
483 | * Initialize for DH * | |
484 | *************************************************/ | |
485 | ||
486 | /* If dhparam is set, expand it, and load up the parameters for DH encryption. | |
487 | ||
488 | Arguments: | |
a799883d | 489 | dhparam DH parameter file or fixed parameter identity string |
7199e1ee | 490 | host connected host, if client; NULL if server |
059ec3d9 PH |
491 | |
492 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
493 | */ | |
494 | ||
495 | static BOOL | |
a799883d | 496 | init_dh(SSL_CTX *sctx, uschar *dhparam, host_item *host) |
059ec3d9 | 497 | { |
059ec3d9 PH |
498 | BIO *bio; |
499 | DH *dh; | |
500 | uschar *dhexpanded; | |
a799883d | 501 | const char *pem; |
059ec3d9 PH |
502 | |
503 | if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded)) | |
504 | return FALSE; | |
505 | ||
0df4ab80 | 506 | if (!dhexpanded || !*dhexpanded) |
a799883d | 507 | bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1); |
a799883d | 508 | else if (dhexpanded[0] == '/') |
059ec3d9 | 509 | { |
0df4ab80 | 510 | if (!(bio = BIO_new_file(CS dhexpanded, "r"))) |
059ec3d9 | 511 | { |
7199e1ee | 512 | tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), |
a799883d PP |
513 | host, US strerror(errno)); |
514 | return FALSE; | |
059ec3d9 | 515 | } |
a799883d PP |
516 | } |
517 | else | |
518 | { | |
519 | if (Ustrcmp(dhexpanded, "none") == 0) | |
059ec3d9 | 520 | { |
a799883d PP |
521 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); |
522 | return TRUE; | |
059ec3d9 | 523 | } |
a799883d | 524 | |
0df4ab80 | 525 | if (!(pem = std_dh_prime_named(dhexpanded))) |
a799883d PP |
526 | { |
527 | tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded), | |
528 | host, US strerror(errno)); | |
529 | return FALSE; | |
530 | } | |
531 | bio = BIO_new_mem_buf(CS pem, -1); | |
532 | } | |
533 | ||
0df4ab80 | 534 | if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL))) |
a799883d | 535 | { |
059ec3d9 | 536 | BIO_free(bio); |
a799883d PP |
537 | tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded), |
538 | host, NULL); | |
539 | return FALSE; | |
540 | } | |
541 | ||
542 | /* Even if it is larger, we silently return success rather than cause things | |
543 | * to fail out, so that a too-large DH will not knock out all TLS; it's a | |
544 | * debatable choice. */ | |
545 | if ((8*DH_size(dh)) > tls_dh_max_bits) | |
546 | { | |
547 | DEBUG(D_tls) | |
548 | debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d", | |
549 | 8*DH_size(dh), tls_dh_max_bits); | |
550 | } | |
551 | else | |
552 | { | |
553 | SSL_CTX_set_tmp_dh(sctx, dh); | |
554 | DEBUG(D_tls) | |
555 | debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n", | |
556 | dhexpanded ? dhexpanded : US"default", 8*DH_size(dh)); | |
059ec3d9 PH |
557 | } |
558 | ||
a799883d PP |
559 | DH_free(dh); |
560 | BIO_free(bio); | |
561 | ||
562 | return TRUE; | |
059ec3d9 PH |
563 | } |
564 | ||
565 | ||
566 | ||
567 | ||
f2de3a33 | 568 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
569 | /************************************************* |
570 | * Load OCSP information into state * | |
571 | *************************************************/ | |
572 | ||
f5d78688 | 573 | /* Called to load the server OCSP response from the given file into memory, once |
3f7eeb86 PP |
574 | caller has determined this is needed. Checks validity. Debugs a message |
575 | if invalid. | |
576 | ||
577 | ASSUMES: single response, for single cert. | |
578 | ||
579 | Arguments: | |
580 | sctx the SSL_CTX* to update | |
581 | cbinfo various parts of session state | |
582 | expanded the filename putatively holding an OCSP response | |
583 | ||
584 | */ | |
585 | ||
586 | static void | |
f5d78688 | 587 | ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded) |
3f7eeb86 PP |
588 | { |
589 | BIO *bio; | |
590 | OCSP_RESPONSE *resp; | |
591 | OCSP_BASICRESP *basic_response; | |
592 | OCSP_SINGLERESP *single_response; | |
593 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
594 | X509_STORE *store; | |
595 | unsigned long verify_flags; | |
596 | int status, reason, i; | |
597 | ||
f5d78688 JH |
598 | cbinfo->u_ocsp.server.file_expanded = string_copy(expanded); |
599 | if (cbinfo->u_ocsp.server.response) | |
3f7eeb86 | 600 | { |
f5d78688 JH |
601 | OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response); |
602 | cbinfo->u_ocsp.server.response = NULL; | |
3f7eeb86 PP |
603 | } |
604 | ||
f5d78688 | 605 | bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb"); |
3f7eeb86 PP |
606 | if (!bio) |
607 | { | |
608 | DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", | |
f5d78688 | 609 | cbinfo->u_ocsp.server.file_expanded); |
3f7eeb86 PP |
610 | return; |
611 | } | |
612 | ||
613 | resp = d2i_OCSP_RESPONSE_bio(bio, NULL); | |
614 | BIO_free(bio); | |
615 | if (!resp) | |
616 | { | |
617 | DEBUG(D_tls) debug_printf("Error reading OCSP response.\n"); | |
618 | return; | |
619 | } | |
620 | ||
621 | status = OCSP_response_status(resp); | |
622 | if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) | |
623 | { | |
624 | DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", | |
625 | OCSP_response_status_str(status), status); | |
f5d78688 | 626 | goto bad; |
3f7eeb86 PP |
627 | } |
628 | ||
629 | basic_response = OCSP_response_get1_basic(resp); | |
630 | if (!basic_response) | |
631 | { | |
632 | DEBUG(D_tls) | |
633 | debug_printf("OCSP response parse error: unable to extract basic response.\n"); | |
f5d78688 | 634 | goto bad; |
3f7eeb86 PP |
635 | } |
636 | ||
637 | store = SSL_CTX_get_cert_store(sctx); | |
638 | verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ | |
639 | ||
640 | /* May need to expose ability to adjust those flags? | |
641 | OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT | |
642 | OCSP_TRUSTOTHER OCSP_NOINTERN */ | |
643 | ||
644 | i = OCSP_basic_verify(basic_response, NULL, store, verify_flags); | |
645 | if (i <= 0) | |
646 | { | |
647 | DEBUG(D_tls) { | |
648 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
649 | debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); | |
f5d78688 JH |
650 | } |
651 | goto bad; | |
3f7eeb86 PP |
652 | } |
653 | ||
654 | /* Here's the simplifying assumption: there's only one response, for the | |
655 | one certificate we use, and nothing for anything else in a chain. If this | |
656 | proves false, we need to extract a cert id from our issued cert | |
657 | (tls_certificate) and use that for OCSP_resp_find_status() (which finds the | |
658 | right cert in the stack and then calls OCSP_single_get0_status()). | |
659 | ||
660 | I'm hoping to avoid reworking a bunch more of how we handle state here. */ | |
661 | single_response = OCSP_resp_get0(basic_response, 0); | |
662 | if (!single_response) | |
663 | { | |
664 | DEBUG(D_tls) | |
665 | debug_printf("Unable to get first response from OCSP basic response.\n"); | |
f5d78688 | 666 | goto bad; |
3f7eeb86 PP |
667 | } |
668 | ||
669 | status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd); | |
f5d78688 | 670 | if (status != V_OCSP_CERTSTATUS_GOOD) |
3f7eeb86 | 671 | { |
f5d78688 JH |
672 | DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n", |
673 | OCSP_cert_status_str(status), status, | |
674 | OCSP_crl_reason_str(reason), reason); | |
675 | goto bad; | |
3f7eeb86 PP |
676 | } |
677 | ||
678 | if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
679 | { | |
680 | DEBUG(D_tls) debug_printf("OCSP status invalid times.\n"); | |
f5d78688 | 681 | goto bad; |
3f7eeb86 PP |
682 | } |
683 | ||
f5d78688 | 684 | supply_response: |
018058b2 | 685 | cbinfo->u_ocsp.server.response = resp; |
f5d78688 JH |
686 | return; |
687 | ||
688 | bad: | |
018058b2 JH |
689 | if (running_in_test_harness) |
690 | { | |
691 | extern char ** environ; | |
692 | uschar ** p; | |
693 | for (p = USS environ; *p != NULL; p++) | |
694 | if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) | |
695 | { | |
696 | DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n"); | |
697 | goto supply_response; | |
698 | } | |
699 | } | |
f5d78688 | 700 | return; |
3f7eeb86 | 701 | } |
f2de3a33 | 702 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
703 | |
704 | ||
705 | ||
706 | ||
7be682ca PP |
707 | /************************************************* |
708 | * Expand key and cert file specs * | |
709 | *************************************************/ | |
710 | ||
f5d78688 | 711 | /* Called once during tls_init and possibly again during TLS setup, for a |
7be682ca PP |
712 | new context, if Server Name Indication was used and tls_sni was seen in |
713 | the certificate string. | |
714 | ||
715 | Arguments: | |
716 | sctx the SSL_CTX* to update | |
717 | cbinfo various parts of session state | |
718 | ||
719 | Returns: OK/DEFER/FAIL | |
720 | */ | |
721 | ||
722 | static int | |
3f7eeb86 | 723 | tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo) |
7be682ca PP |
724 | { |
725 | uschar *expanded; | |
726 | ||
727 | if (cbinfo->certificate == NULL) | |
728 | return OK; | |
729 | ||
d9b2312b JH |
730 | if (Ustrstr(cbinfo->certificate, US"tls_sni") || |
731 | Ustrstr(cbinfo->certificate, US"tls_in_sni") || | |
732 | Ustrstr(cbinfo->certificate, US"tls_out_sni") | |
733 | ) | |
7be682ca PP |
734 | reexpand_tls_files_for_sni = TRUE; |
735 | ||
736 | if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded)) | |
737 | return DEFER; | |
738 | ||
739 | if (expanded != NULL) | |
740 | { | |
741 | DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); | |
742 | if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded)) | |
743 | return tls_error(string_sprintf( | |
744 | "SSL_CTX_use_certificate_chain_file file=%s", expanded), | |
745 | cbinfo->host, NULL); | |
746 | } | |
747 | ||
748 | if (cbinfo->privatekey != NULL && | |
749 | !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded)) | |
750 | return DEFER; | |
751 | ||
752 | /* If expansion was forced to fail, key_expanded will be NULL. If the result | |
753 | of the expansion is an empty string, ignore it also, and assume the private | |
754 | key is in the same file as the certificate. */ | |
755 | ||
756 | if (expanded != NULL && *expanded != 0) | |
757 | { | |
758 | DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); | |
759 | if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM)) | |
760 | return tls_error(string_sprintf( | |
761 | "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL); | |
762 | } | |
763 | ||
f2de3a33 | 764 | #ifndef DISABLE_OCSP |
f5d78688 | 765 | if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL) |
3f7eeb86 | 766 | { |
f5d78688 | 767 | if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded)) |
3f7eeb86 PP |
768 | return DEFER; |
769 | ||
770 | if (expanded != NULL && *expanded != 0) | |
771 | { | |
772 | DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded); | |
f5d78688 JH |
773 | if (cbinfo->u_ocsp.server.file_expanded && |
774 | (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0)) | |
3f7eeb86 PP |
775 | { |
776 | DEBUG(D_tls) | |
777 | debug_printf("tls_ocsp_file value unchanged, using existing values.\n"); | |
778 | } else { | |
779 | ocsp_load_response(sctx, cbinfo, expanded); | |
780 | } | |
781 | } | |
782 | } | |
783 | #endif | |
784 | ||
7be682ca PP |
785 | return OK; |
786 | } | |
787 | ||
788 | ||
789 | ||
790 | ||
791 | /************************************************* | |
792 | * Callback to handle SNI * | |
793 | *************************************************/ | |
794 | ||
795 | /* Called when acting as server during the TLS session setup if a Server Name | |
796 | Indication extension was sent by the client. | |
797 | ||
798 | API documentation is OpenSSL s_server.c implementation. | |
799 | ||
800 | Arguments: | |
801 | s SSL* of the current session | |
802 | ad unknown (part of OpenSSL API) (unused) | |
803 | arg Callback of "our" registered data | |
804 | ||
805 | Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK} | |
806 | */ | |
807 | ||
3bcbbbe2 | 808 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
7be682ca PP |
809 | static int |
810 | tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg) | |
811 | { | |
812 | const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); | |
3f7eeb86 | 813 | tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; |
7be682ca | 814 | int rc; |
3f0945ff | 815 | int old_pool = store_pool; |
7be682ca PP |
816 | |
817 | if (!servername) | |
818 | return SSL_TLSEXT_ERR_OK; | |
819 | ||
3f0945ff | 820 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername, |
7be682ca PP |
821 | reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)"); |
822 | ||
823 | /* Make the extension value available for expansion */ | |
3f0945ff | 824 | store_pool = POOL_PERM; |
817d9f57 | 825 | tls_in.sni = string_copy(US servername); |
3f0945ff | 826 | store_pool = old_pool; |
7be682ca PP |
827 | |
828 | if (!reexpand_tls_files_for_sni) | |
829 | return SSL_TLSEXT_ERR_OK; | |
830 | ||
831 | /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually; | |
832 | not confident that memcpy wouldn't break some internal reference counting. | |
833 | Especially since there's a references struct member, which would be off. */ | |
834 | ||
0df4ab80 | 835 | if (!(server_sni = SSL_CTX_new(SSLv23_server_method()))) |
7be682ca PP |
836 | { |
837 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
838 | DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring); | |
839 | return SSL_TLSEXT_ERR_NOACK; | |
840 | } | |
841 | ||
842 | /* Not sure how many of these are actually needed, since SSL object | |
843 | already exists. Might even need this selfsame callback, for reneg? */ | |
844 | ||
817d9f57 JH |
845 | SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx)); |
846 | SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx)); | |
847 | SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); | |
848 | SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); | |
849 | SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); | |
850 | SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); | |
7be682ca | 851 | if (cbinfo->server_cipher_list) |
817d9f57 | 852 | SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list); |
f2de3a33 | 853 | #ifndef DISABLE_OCSP |
f5d78688 | 854 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 855 | { |
f5d78688 | 856 | SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb); |
14c7b357 | 857 | SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo); |
3f7eeb86 PP |
858 | } |
859 | #endif | |
7be682ca | 860 | |
983207c1 | 861 | rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server); |
7be682ca PP |
862 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
863 | ||
3f7eeb86 PP |
864 | /* do this after setup_certs, because this can require the certs for verifying |
865 | OCSP information. */ | |
817d9f57 | 866 | rc = tls_expand_session_files(server_sni, cbinfo); |
7be682ca PP |
867 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
868 | ||
0df4ab80 JH |
869 | if (!init_dh(server_sni, cbinfo->dhparam, NULL)) |
870 | return SSL_TLSEXT_ERR_NOACK; | |
a799883d | 871 | |
7be682ca | 872 | DEBUG(D_tls) debug_printf("Switching SSL context.\n"); |
817d9f57 | 873 | SSL_set_SSL_CTX(s, server_sni); |
7be682ca PP |
874 | |
875 | return SSL_TLSEXT_ERR_OK; | |
876 | } | |
3bcbbbe2 | 877 | #endif /* EXIM_HAVE_OPENSSL_TLSEXT */ |
7be682ca PP |
878 | |
879 | ||
880 | ||
881 | ||
f2de3a33 | 882 | #ifndef DISABLE_OCSP |
f5d78688 | 883 | |
3f7eeb86 PP |
884 | /************************************************* |
885 | * Callback to handle OCSP Stapling * | |
886 | *************************************************/ | |
887 | ||
888 | /* Called when acting as server during the TLS session setup if the client | |
889 | requests OCSP information with a Certificate Status Request. | |
890 | ||
891 | Documentation via openssl s_server.c and the Apache patch from the OpenSSL | |
892 | project. | |
893 | ||
894 | */ | |
895 | ||
896 | static int | |
f5d78688 | 897 | tls_server_stapling_cb(SSL *s, void *arg) |
3f7eeb86 PP |
898 | { |
899 | const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; | |
900 | uschar *response_der; | |
901 | int response_der_len; | |
902 | ||
af4a1bca JH |
903 | DEBUG(D_tls) |
904 | debug_printf("Received TLS status request (OCSP stapling); %s response.", | |
f5d78688 JH |
905 | cbinfo->u_ocsp.server.response ? "have" : "lack"); |
906 | ||
44662487 | 907 | tls_in.ocsp = OCSP_NOT_RESP; |
f5d78688 | 908 | if (!cbinfo->u_ocsp.server.response) |
3f7eeb86 PP |
909 | return SSL_TLSEXT_ERR_NOACK; |
910 | ||
911 | response_der = NULL; | |
44662487 JH |
912 | response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response, |
913 | &response_der); | |
3f7eeb86 PP |
914 | if (response_der_len <= 0) |
915 | return SSL_TLSEXT_ERR_NOACK; | |
916 | ||
5e55c7a9 | 917 | SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len); |
44662487 | 918 | tls_in.ocsp = OCSP_VFIED; |
3f7eeb86 PP |
919 | return SSL_TLSEXT_ERR_OK; |
920 | } | |
921 | ||
3f7eeb86 | 922 | |
f5d78688 JH |
923 | static void |
924 | time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time) | |
925 | { | |
926 | BIO_printf(bp, "\t%s: ", str); | |
927 | ASN1_GENERALIZEDTIME_print(bp, time); | |
928 | BIO_puts(bp, "\n"); | |
929 | } | |
930 | ||
931 | static int | |
932 | tls_client_stapling_cb(SSL *s, void *arg) | |
933 | { | |
934 | tls_ext_ctx_cb * cbinfo = arg; | |
935 | const unsigned char * p; | |
936 | int len; | |
937 | OCSP_RESPONSE * rsp; | |
938 | OCSP_BASICRESP * bs; | |
939 | int i; | |
940 | ||
941 | DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):"); | |
942 | len = SSL_get_tlsext_status_ocsp_resp(s, &p); | |
943 | if(!p) | |
944 | { | |
44662487 JH |
945 | /* Expect this when we requested ocsp but got none */ |
946 | if ( cbinfo->u_ocsp.client.verify_required | |
947 | && log_extra_selector & LX_tls_cipher) | |
948 | log_write(0, LOG_MAIN, "Received TLS status callback, null content"); | |
f5d78688 JH |
949 | else |
950 | DEBUG(D_tls) debug_printf(" null\n"); | |
44662487 | 951 | return cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 952 | } |
018058b2 | 953 | |
f5d78688 JH |
954 | if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) |
955 | { | |
018058b2 | 956 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 | 957 | if (log_extra_selector & LX_tls_cipher) |
1eca31ca | 958 | log_write(0, LOG_MAIN, "Received TLS cert status response, parse error"); |
f5d78688 JH |
959 | else |
960 | DEBUG(D_tls) debug_printf(" parse error\n"); | |
961 | return 0; | |
962 | } | |
963 | ||
964 | if(!(bs = OCSP_response_get1_basic(rsp))) | |
965 | { | |
018058b2 | 966 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 | 967 | if (log_extra_selector & LX_tls_cipher) |
1eca31ca | 968 | log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response"); |
f5d78688 JH |
969 | else |
970 | DEBUG(D_tls) debug_printf(" error parsing response\n"); | |
971 | OCSP_RESPONSE_free(rsp); | |
972 | return 0; | |
973 | } | |
974 | ||
975 | /* We'd check the nonce here if we'd put one in the request. */ | |
976 | /* However that would defeat cacheability on the server so we don't. */ | |
977 | ||
f5d78688 JH |
978 | /* This section of code reworked from OpenSSL apps source; |
979 | The OpenSSL Project retains copyright: | |
980 | Copyright (c) 1999 The OpenSSL Project. All rights reserved. | |
981 | */ | |
982 | { | |
983 | BIO * bp = NULL; | |
f5d78688 JH |
984 | int status, reason; |
985 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
986 | ||
987 | DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE); | |
988 | ||
989 | /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */ | |
990 | ||
991 | /* Use the chain that verified the server cert to verify the stapled info */ | |
992 | /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */ | |
993 | ||
44662487 JH |
994 | if ((i = OCSP_basic_verify(bs, NULL, |
995 | cbinfo->u_ocsp.client.verify_store, 0)) <= 0) | |
f5d78688 | 996 | { |
018058b2 | 997 | tls_out.ocsp = OCSP_FAILED; |
1eca31ca JH |
998 | if (log_extra_selector & LX_tls_cipher) |
999 | log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable"); | |
f5d78688 JH |
1000 | BIO_printf(bp, "OCSP response verify failure\n"); |
1001 | ERR_print_errors(bp); | |
44662487 | 1002 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 JH |
1003 | goto out; |
1004 | } | |
1005 | ||
1006 | BIO_printf(bp, "OCSP response well-formed and signed OK\n"); | |
1007 | ||
1008 | { | |
1009 | STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; | |
1010 | OCSP_SINGLERESP * single; | |
1011 | ||
1012 | if (sk_OCSP_SINGLERESP_num(sresp) != 1) | |
1013 | { | |
018058b2 | 1014 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1015 | log_write(0, LOG_MAIN, "OCSP stapling " |
1016 | "with multiple responses not handled"); | |
1017 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
f5d78688 JH |
1018 | goto out; |
1019 | } | |
1020 | single = OCSP_resp_get0(bs, 0); | |
44662487 JH |
1021 | status = OCSP_single_get0_status(single, &reason, &rev, |
1022 | &thisupd, &nextupd); | |
f5d78688 JH |
1023 | } |
1024 | ||
f5d78688 JH |
1025 | DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd); |
1026 | DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd); | |
44662487 JH |
1027 | if (!OCSP_check_validity(thisupd, nextupd, |
1028 | EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
f5d78688 | 1029 | { |
018058b2 | 1030 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
1031 | DEBUG(D_tls) ERR_print_errors(bp); |
1032 | log_write(0, LOG_MAIN, "Server OSCP dates invalid"); | |
44662487 | 1033 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 1034 | } |
44662487 | 1035 | else |
f5d78688 | 1036 | { |
44662487 JH |
1037 | DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n", |
1038 | OCSP_cert_status_str(status)); | |
1039 | switch(status) | |
1040 | { | |
1041 | case V_OCSP_CERTSTATUS_GOOD: | |
44662487 | 1042 | tls_out.ocsp = OCSP_VFIED; |
018058b2 | 1043 | i = 1; |
44662487 JH |
1044 | break; |
1045 | case V_OCSP_CERTSTATUS_REVOKED: | |
018058b2 | 1046 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1047 | log_write(0, LOG_MAIN, "Server certificate revoked%s%s", |
1048 | reason != -1 ? "; reason: " : "", | |
1049 | reason != -1 ? OCSP_crl_reason_str(reason) : ""); | |
1050 | DEBUG(D_tls) time_print(bp, "Revocation Time", rev); | |
1051 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1052 | break; | |
1053 | default: | |
018058b2 | 1054 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1055 | log_write(0, LOG_MAIN, |
1056 | "Server certificate status unknown, in OCSP stapling"); | |
1057 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1058 | break; | |
1059 | } | |
f5d78688 JH |
1060 | } |
1061 | out: | |
1062 | BIO_free(bp); | |
1063 | } | |
1064 | ||
1065 | OCSP_RESPONSE_free(rsp); | |
1066 | return i; | |
1067 | } | |
f2de3a33 | 1068 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
1069 | |
1070 | ||
059ec3d9 PH |
1071 | /************************************************* |
1072 | * Initialize for TLS * | |
1073 | *************************************************/ | |
1074 | ||
e51c7be2 JH |
1075 | /* Called from both server and client code, to do preliminary initialization |
1076 | of the library. We allocate and return a context structure. | |
059ec3d9 PH |
1077 | |
1078 | Arguments: | |
946ecbe0 | 1079 | ctxp returned SSL context |
059ec3d9 PH |
1080 | host connected host, if client; NULL if server |
1081 | dhparam DH parameter file | |
1082 | certificate certificate file | |
1083 | privatekey private key | |
f5d78688 | 1084 | ocsp_file file of stapling info (server); flag for require ocsp (client) |
059ec3d9 | 1085 | addr address if client; NULL if server (for some randomness) |
946ecbe0 | 1086 | cbp place to put allocated callback context |
059ec3d9 PH |
1087 | |
1088 | Returns: OK/DEFER/FAIL | |
1089 | */ | |
1090 | ||
1091 | static int | |
817d9f57 | 1092 | tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate, |
3f7eeb86 | 1093 | uschar *privatekey, |
f2de3a33 | 1094 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1095 | uschar *ocsp_file, |
1096 | #endif | |
817d9f57 | 1097 | address_item *addr, tls_ext_ctx_cb ** cbp) |
059ec3d9 | 1098 | { |
77bb000f | 1099 | long init_options; |
7be682ca | 1100 | int rc; |
77bb000f | 1101 | BOOL okay; |
a7538db1 | 1102 | tls_ext_ctx_cb * cbinfo; |
7be682ca PP |
1103 | |
1104 | cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); | |
1105 | cbinfo->certificate = certificate; | |
1106 | cbinfo->privatekey = privatekey; | |
f2de3a33 | 1107 | #ifndef DISABLE_OCSP |
f5d78688 JH |
1108 | if ((cbinfo->is_server = host==NULL)) |
1109 | { | |
1110 | cbinfo->u_ocsp.server.file = ocsp_file; | |
1111 | cbinfo->u_ocsp.server.file_expanded = NULL; | |
1112 | cbinfo->u_ocsp.server.response = NULL; | |
1113 | } | |
1114 | else | |
1115 | cbinfo->u_ocsp.client.verify_store = NULL; | |
3f7eeb86 | 1116 | #endif |
7be682ca | 1117 | cbinfo->dhparam = dhparam; |
0df4ab80 | 1118 | cbinfo->server_cipher_list = NULL; |
7be682ca | 1119 | cbinfo->host = host; |
a7538db1 JH |
1120 | #ifdef EXPERIMENTAL_TPDA |
1121 | cbinfo->event_action = NULL; | |
1122 | #endif | |
77bb000f | 1123 | |
059ec3d9 PH |
1124 | SSL_load_error_strings(); /* basic set up */ |
1125 | OpenSSL_add_ssl_algorithms(); | |
1126 | ||
388d6564 | 1127 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) |
77bb000f | 1128 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the |
a0475b69 TK |
1129 | list of available digests. */ |
1130 | EVP_add_digest(EVP_sha256()); | |
cf1ef1a9 | 1131 | #endif |
a0475b69 | 1132 | |
f0f5a555 PP |
1133 | /* Create a context. |
1134 | The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant | |
1135 | negotiation in the different methods; as far as I can tell, the only | |
1136 | *_{server,client}_method which allows negotiation is SSLv23, which exists even | |
1137 | when OpenSSL is built without SSLv2 support. | |
1138 | By disabling with openssl_options, we can let admins re-enable with the | |
1139 | existing knob. */ | |
059ec3d9 | 1140 | |
817d9f57 | 1141 | *ctxp = SSL_CTX_new((host == NULL)? |
059ec3d9 PH |
1142 | SSLv23_server_method() : SSLv23_client_method()); |
1143 | ||
817d9f57 | 1144 | if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL); |
059ec3d9 PH |
1145 | |
1146 | /* It turns out that we need to seed the random number generator this early in | |
1147 | order to get the full complement of ciphers to work. It took me roughly a day | |
1148 | of work to discover this by experiment. | |
1149 | ||
1150 | On systems that have /dev/urandom, SSL may automatically seed itself from | |
1151 | there. Otherwise, we have to make something up as best we can. Double check | |
1152 | afterwards. */ | |
1153 | ||
1154 | if (!RAND_status()) | |
1155 | { | |
1156 | randstuff r; | |
9e3331ea | 1157 | gettimeofday(&r.tv, NULL); |
059ec3d9 PH |
1158 | r.p = getpid(); |
1159 | ||
1160 | RAND_seed((uschar *)(&r), sizeof(r)); | |
1161 | RAND_seed((uschar *)big_buffer, big_buffer_size); | |
1162 | if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr)); | |
1163 | ||
1164 | if (!RAND_status()) | |
7199e1ee | 1165 | return tls_error(US"RAND_status", host, |
5ca6d115 | 1166 | US"unable to seed random number generator"); |
059ec3d9 PH |
1167 | } |
1168 | ||
1169 | /* Set up the information callback, which outputs if debugging is at a suitable | |
1170 | level. */ | |
1171 | ||
817d9f57 | 1172 | SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback); |
059ec3d9 | 1173 | |
c80c5570 | 1174 | /* Automatically re-try reads/writes after renegotiation. */ |
817d9f57 | 1175 | (void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY); |
c80c5570 | 1176 | |
77bb000f PP |
1177 | /* Apply administrator-supplied work-arounds. |
1178 | Historically we applied just one requested option, | |
1179 | SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we | |
1180 | moved to an administrator-controlled list of options to specify and | |
1181 | grandfathered in the first one as the default value for "openssl_options". | |
059ec3d9 | 1182 | |
77bb000f PP |
1183 | No OpenSSL version number checks: the options we accept depend upon the |
1184 | availability of the option value macros from OpenSSL. */ | |
059ec3d9 | 1185 | |
77bb000f PP |
1186 | okay = tls_openssl_options_parse(openssl_options, &init_options); |
1187 | if (!okay) | |
73a46702 | 1188 | return tls_error(US"openssl_options parsing failed", host, NULL); |
77bb000f PP |
1189 | |
1190 | if (init_options) | |
1191 | { | |
1192 | DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); | |
817d9f57 | 1193 | if (!(SSL_CTX_set_options(*ctxp, init_options))) |
77bb000f PP |
1194 | return tls_error(string_sprintf( |
1195 | "SSL_CTX_set_option(%#lx)", init_options), host, NULL); | |
1196 | } | |
1197 | else | |
1198 | DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); | |
059ec3d9 PH |
1199 | |
1200 | /* Initialize with DH parameters if supplied */ | |
1201 | ||
817d9f57 | 1202 | if (!init_dh(*ctxp, dhparam, host)) return DEFER; |
059ec3d9 | 1203 | |
3f7eeb86 | 1204 | /* Set up certificate and key (and perhaps OCSP info) */ |
059ec3d9 | 1205 | |
817d9f57 | 1206 | rc = tls_expand_session_files(*ctxp, cbinfo); |
7be682ca | 1207 | if (rc != OK) return rc; |
c91535f3 | 1208 | |
7be682ca | 1209 | /* If we need to handle SNI, do so */ |
3bcbbbe2 | 1210 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
f5d78688 | 1211 | if (host == NULL) /* server */ |
3f0945ff | 1212 | { |
f2de3a33 | 1213 | # ifndef DISABLE_OCSP |
f5d78688 | 1214 | /* We check u_ocsp.server.file, not server.response, because we care about if |
3f7eeb86 PP |
1215 | the option exists, not what the current expansion might be, as SNI might |
1216 | change the certificate and OCSP file in use between now and the time the | |
1217 | callback is invoked. */ | |
f5d78688 | 1218 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1219 | { |
f5d78688 | 1220 | SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb); |
5e55c7a9 | 1221 | SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo); |
3f7eeb86 | 1222 | } |
f5d78688 | 1223 | # endif |
3f0945ff PP |
1224 | /* We always do this, so that $tls_sni is available even if not used in |
1225 | tls_certificate */ | |
817d9f57 JH |
1226 | SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb); |
1227 | SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo); | |
3f0945ff | 1228 | } |
f2de3a33 | 1229 | # ifndef DISABLE_OCSP |
f5d78688 JH |
1230 | else /* client */ |
1231 | if(ocsp_file) /* wanting stapling */ | |
1232 | { | |
1233 | if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new())) | |
1234 | { | |
1235 | DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n"); | |
1236 | return FAIL; | |
1237 | } | |
1238 | SSL_CTX_set_tlsext_status_cb(*ctxp, tls_client_stapling_cb); | |
1239 | SSL_CTX_set_tlsext_status_arg(*ctxp, cbinfo); | |
1240 | } | |
1241 | # endif | |
7be682ca | 1242 | #endif |
059ec3d9 | 1243 | |
e51c7be2 JH |
1244 | #ifdef EXPERIMENTAL_CERTNAMES |
1245 | cbinfo->verify_cert_hostnames = NULL; | |
1246 | #endif | |
1247 | ||
059ec3d9 PH |
1248 | /* Set up the RSA callback */ |
1249 | ||
817d9f57 | 1250 | SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback); |
059ec3d9 PH |
1251 | |
1252 | /* Finally, set the timeout, and we are done */ | |
1253 | ||
817d9f57 | 1254 | SSL_CTX_set_timeout(*ctxp, ssl_session_timeout); |
059ec3d9 | 1255 | DEBUG(D_tls) debug_printf("Initialized TLS\n"); |
7be682ca | 1256 | |
817d9f57 | 1257 | *cbp = cbinfo; |
7be682ca | 1258 | |
059ec3d9 PH |
1259 | return OK; |
1260 | } | |
1261 | ||
1262 | ||
1263 | ||
1264 | ||
1265 | /************************************************* | |
1266 | * Get name of cipher in use * | |
1267 | *************************************************/ | |
1268 | ||
817d9f57 | 1269 | /* |
059ec3d9 | 1270 | Argument: pointer to an SSL structure for the connection |
817d9f57 JH |
1271 | buffer to use for answer |
1272 | size of buffer | |
1273 | pointer to number of bits for cipher | |
059ec3d9 PH |
1274 | Returns: nothing |
1275 | */ | |
1276 | ||
1277 | static void | |
817d9f57 | 1278 | construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits) |
059ec3d9 | 1279 | { |
57b3a7f5 PP |
1280 | /* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't |
1281 | yet reflect that. It should be a safe change anyway, even 0.9.8 versions have | |
1282 | the accessor functions use const in the prototype. */ | |
1283 | const SSL_CIPHER *c; | |
d9784128 | 1284 | const uschar *ver; |
059ec3d9 | 1285 | |
d9784128 | 1286 | ver = (const uschar *)SSL_get_version(ssl); |
059ec3d9 | 1287 | |
57b3a7f5 | 1288 | c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); |
817d9f57 | 1289 | SSL_CIPHER_get_bits(c, bits); |
059ec3d9 | 1290 | |
817d9f57 JH |
1291 | string_format(cipherbuf, bsize, "%s:%s:%u", ver, |
1292 | SSL_CIPHER_get_name(c), *bits); | |
059ec3d9 PH |
1293 | |
1294 | DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf); | |
1295 | } | |
1296 | ||
1297 | ||
1298 | ||
1299 | ||
1300 | ||
1301 | /************************************************* | |
1302 | * Set up for verifying certificates * | |
1303 | *************************************************/ | |
1304 | ||
1305 | /* Called by both client and server startup | |
1306 | ||
1307 | Arguments: | |
7be682ca | 1308 | sctx SSL_CTX* to initialise |
059ec3d9 PH |
1309 | certs certs file or NULL |
1310 | crl CRL file or NULL | |
1311 | host NULL in a server; the remote host in a client | |
1312 | optional TRUE if called from a server for a host in tls_try_verify_hosts; | |
1313 | otherwise passed as FALSE | |
983207c1 | 1314 | cert_vfy_cb Callback function for certificate verification |
059ec3d9 PH |
1315 | |
1316 | Returns: OK/DEFER/FAIL | |
1317 | */ | |
1318 | ||
1319 | static int | |
983207c1 JH |
1320 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
1321 | int (*cert_vfy_cb)(int, X509_STORE_CTX *) ) | |
059ec3d9 PH |
1322 | { |
1323 | uschar *expcerts, *expcrl; | |
1324 | ||
1325 | if (!expand_check(certs, US"tls_verify_certificates", &expcerts)) | |
1326 | return DEFER; | |
1327 | ||
26e72755 | 1328 | if (expcerts != NULL && *expcerts != '\0') |
059ec3d9 PH |
1329 | { |
1330 | struct stat statbuf; | |
7be682ca | 1331 | if (!SSL_CTX_set_default_verify_paths(sctx)) |
7199e1ee | 1332 | return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL); |
059ec3d9 PH |
1333 | |
1334 | if (Ustat(expcerts, &statbuf) < 0) | |
1335 | { | |
1336 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1337 | "failed to stat %s for certificates", expcerts); | |
1338 | return DEFER; | |
1339 | } | |
1340 | else | |
1341 | { | |
1342 | uschar *file, *dir; | |
1343 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
1344 | { file = NULL; dir = expcerts; } | |
1345 | else | |
1346 | { file = expcerts; dir = NULL; } | |
1347 | ||
1348 | /* If a certificate file is empty, the next function fails with an | |
1349 | unhelpful error message. If we skip it, we get the correct behaviour (no | |
1350 | certificates are recognized, but the error message is still misleading (it | |
1351 | says no certificate was supplied.) But this is better. */ | |
1352 | ||
1353 | if ((file == NULL || statbuf.st_size > 0) && | |
7be682ca | 1354 | !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) |
7199e1ee | 1355 | return tls_error(US"SSL_CTX_load_verify_locations", host, NULL); |
059ec3d9 PH |
1356 | |
1357 | if (file != NULL) | |
1358 | { | |
7be682ca | 1359 | SSL_CTX_set_client_CA_list(sctx, SSL_load_client_CA_file(CS file)); |
059ec3d9 PH |
1360 | } |
1361 | } | |
1362 | ||
1363 | /* Handle a certificate revocation list. */ | |
1364 | ||
1365 | #if OPENSSL_VERSION_NUMBER > 0x00907000L | |
1366 | ||
8b417f2c PH |
1367 | /* This bit of code is now the version supplied by Lars Mainka. (I have |
1368 | * merely reformatted it into the Exim code style.) | |
1369 | ||
1370 | * "From here I changed the code to add support for multiple crl's | |
1371 | * in pem format in one file or to support hashed directory entries in | |
1372 | * pem format instead of a file. This method now uses the library function | |
1373 | * X509_STORE_load_locations to add the CRL location to the SSL context. | |
1374 | * OpenSSL will then handle the verify against CA certs and CRLs by | |
1375 | * itself in the verify callback." */ | |
1376 | ||
059ec3d9 PH |
1377 | if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER; |
1378 | if (expcrl != NULL && *expcrl != 0) | |
1379 | { | |
8b417f2c PH |
1380 | struct stat statbufcrl; |
1381 | if (Ustat(expcrl, &statbufcrl) < 0) | |
1382 | { | |
1383 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1384 | "failed to stat %s for certificates revocation lists", expcrl); | |
1385 | return DEFER; | |
1386 | } | |
1387 | else | |
059ec3d9 | 1388 | { |
8b417f2c PH |
1389 | /* is it a file or directory? */ |
1390 | uschar *file, *dir; | |
7be682ca | 1391 | X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx); |
8b417f2c | 1392 | if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR) |
059ec3d9 | 1393 | { |
8b417f2c PH |
1394 | file = NULL; |
1395 | dir = expcrl; | |
1396 | DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir); | |
059ec3d9 PH |
1397 | } |
1398 | else | |
1399 | { | |
8b417f2c PH |
1400 | file = expcrl; |
1401 | dir = NULL; | |
1402 | DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); | |
059ec3d9 | 1403 | } |
8b417f2c | 1404 | if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) |
7199e1ee | 1405 | return tls_error(US"X509_STORE_load_locations", host, NULL); |
8b417f2c PH |
1406 | |
1407 | /* setting the flags to check against the complete crl chain */ | |
1408 | ||
1409 | X509_STORE_set_flags(cvstore, | |
1410 | X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL); | |
059ec3d9 | 1411 | } |
059ec3d9 PH |
1412 | } |
1413 | ||
1414 | #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ | |
1415 | ||
1416 | /* If verification is optional, don't fail if no certificate */ | |
1417 | ||
7be682ca | 1418 | SSL_CTX_set_verify(sctx, |
059ec3d9 | 1419 | SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT), |
983207c1 | 1420 | cert_vfy_cb); |
059ec3d9 PH |
1421 | } |
1422 | ||
1423 | return OK; | |
1424 | } | |
1425 | ||
1426 | ||
1427 | ||
1428 | /************************************************* | |
1429 | * Start a TLS session in a server * | |
1430 | *************************************************/ | |
1431 | ||
1432 | /* This is called when Exim is running as a server, after having received | |
1433 | the STARTTLS command. It must respond to that command, and then negotiate | |
1434 | a TLS session. | |
1435 | ||
1436 | Arguments: | |
1437 | require_ciphers allowed ciphers | |
1438 | ||
1439 | Returns: OK on success | |
1440 | DEFER for errors before the start of the negotiation | |
1441 | FAIL for errors during the negotation; the server can't | |
1442 | continue running. | |
1443 | */ | |
1444 | ||
1445 | int | |
17c76198 | 1446 | tls_server_start(const uschar *require_ciphers) |
059ec3d9 PH |
1447 | { |
1448 | int rc; | |
1449 | uschar *expciphers; | |
7be682ca | 1450 | tls_ext_ctx_cb *cbinfo; |
817d9f57 | 1451 | static uschar cipherbuf[256]; |
059ec3d9 PH |
1452 | |
1453 | /* Check for previous activation */ | |
1454 | ||
817d9f57 | 1455 | if (tls_in.active >= 0) |
059ec3d9 | 1456 | { |
5ca6d115 | 1457 | tls_error(US"STARTTLS received after TLS started", NULL, US""); |
059ec3d9 PH |
1458 | smtp_printf("554 Already in TLS\r\n"); |
1459 | return FAIL; | |
1460 | } | |
1461 | ||
1462 | /* Initialize the SSL library. If it fails, it will already have logged | |
1463 | the error. */ | |
1464 | ||
817d9f57 | 1465 | rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey, |
f2de3a33 | 1466 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1467 | tls_ocsp_file, |
1468 | #endif | |
817d9f57 | 1469 | NULL, &server_static_cbinfo); |
059ec3d9 | 1470 | if (rc != OK) return rc; |
817d9f57 | 1471 | cbinfo = server_static_cbinfo; |
059ec3d9 PH |
1472 | |
1473 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers)) | |
1474 | return FAIL; | |
1475 | ||
1476 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
17c76198 PP |
1477 | were historically separated by underscores. So that I can use either form in my |
1478 | tests, and also for general convenience, we turn underscores into hyphens here. | |
1479 | */ | |
059ec3d9 PH |
1480 | |
1481 | if (expciphers != NULL) | |
1482 | { | |
1483 | uschar *s = expciphers; | |
1484 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1485 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1486 | if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) |
7199e1ee | 1487 | return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL); |
7be682ca | 1488 | cbinfo->server_cipher_list = expciphers; |
059ec3d9 PH |
1489 | } |
1490 | ||
1491 | /* If this is a host for which certificate verification is mandatory or | |
1492 | optional, set up appropriately. */ | |
1493 | ||
817d9f57 | 1494 | tls_in.certificate_verified = FALSE; |
53a7196b JH |
1495 | #ifdef EXPERIMENTAL_DANE |
1496 | tls_in.dane_verified = FALSE; | |
1497 | #endif | |
a2ff477a | 1498 | server_verify_callback_called = FALSE; |
059ec3d9 PH |
1499 | |
1500 | if (verify_check_host(&tls_verify_hosts) == OK) | |
1501 | { | |
983207c1 JH |
1502 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
1503 | FALSE, verify_callback_server); | |
059ec3d9 | 1504 | if (rc != OK) return rc; |
a2ff477a | 1505 | server_verify_optional = FALSE; |
059ec3d9 PH |
1506 | } |
1507 | else if (verify_check_host(&tls_try_verify_hosts) == OK) | |
1508 | { | |
983207c1 JH |
1509 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
1510 | TRUE, verify_callback_server); | |
059ec3d9 | 1511 | if (rc != OK) return rc; |
a2ff477a | 1512 | server_verify_optional = TRUE; |
059ec3d9 PH |
1513 | } |
1514 | ||
1515 | /* Prepare for new connection */ | |
1516 | ||
817d9f57 | 1517 | if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL); |
da3ad30d PP |
1518 | |
1519 | /* Warning: we used to SSL_clear(ssl) here, it was removed. | |
1520 | * | |
1521 | * With the SSL_clear(), we get strange interoperability bugs with | |
1522 | * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in | |
1523 | * OpenSSL itself, as a clear should not lead to inability to follow protocols. | |
1524 | * | |
1525 | * The SSL_clear() call is to let an existing SSL* be reused, typically after | |
1526 | * session shutdown. In this case, we have a brand new object and there's no | |
1527 | * obvious reason to immediately clear it. I'm guessing that this was | |
1528 | * originally added because of incomplete initialisation which the clear fixed, | |
1529 | * in some historic release. | |
1530 | */ | |
059ec3d9 PH |
1531 | |
1532 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
1533 | on connection, where outputting anything now upsets the clients and tends to | |
1534 | make them disconnect. We need to have an explicit fflush() here, to force out | |
1535 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
1536 | mode, the fflush() happens when smtp_getc() is called. */ | |
1537 | ||
817d9f57 JH |
1538 | SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1539 | if (!tls_in.on_connect) | |
059ec3d9 PH |
1540 | { |
1541 | smtp_printf("220 TLS go ahead\r\n"); | |
1542 | fflush(smtp_out); | |
1543 | } | |
1544 | ||
1545 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
1546 | that the OpenSSL library doesn't. */ | |
1547 | ||
817d9f57 JH |
1548 | SSL_set_wfd(server_ssl, fileno(smtp_out)); |
1549 | SSL_set_rfd(server_ssl, fileno(smtp_in)); | |
1550 | SSL_set_accept_state(server_ssl); | |
059ec3d9 PH |
1551 | |
1552 | DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); | |
1553 | ||
1554 | sigalrm_seen = FALSE; | |
1555 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 | 1556 | rc = SSL_accept(server_ssl); |
059ec3d9 PH |
1557 | alarm(0); |
1558 | ||
1559 | if (rc <= 0) | |
1560 | { | |
7199e1ee | 1561 | tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL); |
77bb000f PP |
1562 | if (ERR_get_error() == 0) |
1563 | log_write(0, LOG_MAIN, | |
a053d125 | 1564 | "TLS client disconnected cleanly (rejected our certificate?)"); |
059ec3d9 PH |
1565 | return FAIL; |
1566 | } | |
1567 | ||
1568 | DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); | |
1569 | ||
1570 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
1571 | and initialize things. */ | |
1572 | ||
817d9f57 JH |
1573 | construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits); |
1574 | tls_in.cipher = cipherbuf; | |
059ec3d9 PH |
1575 | |
1576 | DEBUG(D_tls) | |
1577 | { | |
1578 | uschar buf[2048]; | |
817d9f57 | 1579 | if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL) |
059ec3d9 PH |
1580 | debug_printf("Shared ciphers: %s\n", buf); |
1581 | } | |
1582 | ||
9d1c15ef JH |
1583 | /* Record the certificate we presented */ |
1584 | { | |
1585 | X509 * crt = SSL_get_certificate(server_ssl); | |
1586 | tls_in.ourcert = crt ? X509_dup(crt) : NULL; | |
1587 | } | |
059ec3d9 | 1588 | |
817d9f57 JH |
1589 | /* Only used by the server-side tls (tls_in), including tls_getc. |
1590 | Client-side (tls_out) reads (seem to?) go via | |
1591 | smtp_read_response()/ip_recv(). | |
1592 | Hence no need to duplicate for _in and _out. | |
1593 | */ | |
059ec3d9 PH |
1594 | ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
1595 | ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; | |
1596 | ssl_xfer_eof = ssl_xfer_error = 0; | |
1597 | ||
1598 | receive_getc = tls_getc; | |
1599 | receive_ungetc = tls_ungetc; | |
1600 | receive_feof = tls_feof; | |
1601 | receive_ferror = tls_ferror; | |
58eb016e | 1602 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 1603 | |
817d9f57 | 1604 | tls_in.active = fileno(smtp_out); |
059ec3d9 PH |
1605 | return OK; |
1606 | } | |
1607 | ||
1608 | ||
1609 | ||
1610 | ||
043b1248 JH |
1611 | static int |
1612 | tls_client_basic_ctx_init(SSL_CTX * ctx, | |
1613 | host_item * host, smtp_transport_options_block * ob | |
1614 | #ifdef EXPERIMENTAL_CERTNAMES | |
1615 | , tls_ext_ctx_cb * cbinfo | |
1616 | #endif | |
1617 | ) | |
1618 | { | |
1619 | int rc; | |
1620 | /* stick to the old behaviour for compatibility if tls_verify_certificates is | |
1621 | set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only | |
1622 | the specified host patterns if one of them is defined */ | |
1623 | ||
1624 | if ((!ob->tls_verify_hosts && !ob->tls_try_verify_hosts) || | |
1625 | (verify_check_host(&ob->tls_verify_hosts) == OK)) | |
1626 | { | |
1627 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
1628 | ob->tls_crl, host, FALSE, verify_callback_client)) != OK) | |
1629 | return rc; | |
1630 | client_verify_optional = FALSE; | |
1631 | ||
1632 | #ifdef EXPERIMENTAL_CERTNAMES | |
1633 | if (ob->tls_verify_cert_hostnames) | |
1634 | { | |
1635 | if (!expand_check(ob->tls_verify_cert_hostnames, | |
1636 | US"tls_verify_cert_hostnames", | |
1637 | &cbinfo->verify_cert_hostnames)) | |
1638 | return FAIL; | |
1639 | if (cbinfo->verify_cert_hostnames) | |
1640 | DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", | |
1641 | cbinfo->verify_cert_hostnames); | |
1642 | } | |
1643 | #endif | |
1644 | } | |
1645 | else if (verify_check_host(&ob->tls_try_verify_hosts) == OK) | |
1646 | { | |
1647 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
1648 | ob->tls_crl, host, TRUE, verify_callback_client)) != OK) | |
1649 | return rc; | |
1650 | client_verify_optional = TRUE; | |
1651 | } | |
1652 | ||
1653 | return OK; | |
1654 | } | |
059ec3d9 | 1655 | |
fde080a4 JH |
1656 | |
1657 | #ifdef EXPERIMENTAL_DANE | |
1658 | static int | |
1659 | tlsa_lookup(host_item * host, dns_answer * dnsa, | |
1660 | BOOL dane_required, BOOL * dane) | |
1661 | { | |
1662 | /* move this out to host.c given the similarity to dns_lookup() ? */ | |
1663 | uschar buffer[300]; | |
1664 | uschar * fullname = buffer; | |
1665 | ||
1666 | /* TLSA lookup string */ | |
1667 | (void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port, host->name); | |
1668 | ||
1669 | switch (dns_lookup(dnsa, buffer, T_TLSA, &fullname)) | |
1670 | { | |
1671 | case DNS_AGAIN: | |
1672 | return DEFER; /* just defer this TLS'd conn */ | |
1673 | ||
1674 | default: | |
1675 | case DNS_FAIL: | |
1676 | if (dane_required) | |
1677 | { | |
1678 | log_write(0, LOG_MAIN, "DANE error: TLSA lookup failed"); | |
1679 | return FAIL; | |
1680 | } | |
1681 | break; | |
1682 | ||
1683 | case DNS_SUCCEED: | |
1684 | if (!dns_is_secure(dnsa)) | |
1685 | { | |
1686 | log_write(0, LOG_MAIN, "DANE error: TLSA lookup not DNSSEC"); | |
1687 | return DEFER; | |
1688 | } | |
1689 | *dane = TRUE; | |
1690 | break; | |
1691 | } | |
1692 | return OK; | |
1693 | } | |
1694 | ||
1695 | ||
1696 | static int | |
1697 | dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa) | |
1698 | { | |
1699 | dns_record * rr; | |
1700 | dns_scan dnss; | |
1701 | const char * hostnames[2] = { CS host->name, NULL }; | |
1702 | int found = 0; | |
1703 | ||
1704 | if (DANESSL_init(ssl, NULL, hostnames) != 1) | |
1705 | return tls_error(US"hostnames load", host, NULL); | |
1706 | ||
1707 | for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); | |
1708 | rr; | |
1709 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) | |
1710 | ) if (rr->type == T_TLSA) | |
1711 | { | |
1712 | uschar * p = rr->data; | |
1713 | uint8_t usage, selector, mtype; | |
1714 | const char * mdname; | |
1715 | ||
1716 | found++; | |
1717 | usage = *p++; | |
1718 | selector = *p++; | |
1719 | mtype = *p++; | |
1720 | ||
1721 | switch (mtype) | |
1722 | { | |
1723 | default: | |
1724 | log_write(0, LOG_MAIN, | |
1725 | "DANE error: TLSA record w/bad mtype 0x%x", mtype); | |
1726 | return FAIL; | |
1727 | case 0: mdname = NULL; break; | |
1728 | case 1: mdname = "sha256"; break; | |
1729 | case 2: mdname = "sha512"; break; | |
1730 | } | |
1731 | ||
1732 | switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3)) | |
1733 | { | |
1734 | default: | |
1735 | case 0: /* action not taken */ | |
1736 | return tls_error(US"tlsa load", host, NULL); | |
1737 | case 1: break; | |
1738 | } | |
594706ea JH |
1739 | |
1740 | tls_out.tlsa_usage |= 1<<usage; | |
fde080a4 JH |
1741 | } |
1742 | ||
1743 | if (found) | |
1744 | return OK; | |
1745 | ||
1746 | log_write(0, LOG_MAIN, "DANE error: No TLSA records"); | |
1747 | return FAIL; | |
1748 | } | |
1749 | #endif /*EXPERIMENTAL_DANE*/ | |
1750 | ||
1751 | ||
1752 | ||
059ec3d9 PH |
1753 | /************************************************* |
1754 | * Start a TLS session in a client * | |
1755 | *************************************************/ | |
1756 | ||
1757 | /* Called from the smtp transport after STARTTLS has been accepted. | |
1758 | ||
1759 | Argument: | |
1760 | fd the fd of the connection | |
1761 | host connected host (for messages) | |
83da1223 | 1762 | addr the first address |
a7538db1 | 1763 | tb transport (always smtp) |
059ec3d9 PH |
1764 | |
1765 | Returns: OK on success | |
1766 | FAIL otherwise - note that tls_error() will not give DEFER | |
1767 | because this is not a server | |
1768 | */ | |
1769 | ||
1770 | int | |
f5d78688 | 1771 | tls_client_start(int fd, host_item *host, address_item *addr, |
a7538db1 | 1772 | transport_instance *tb) |
059ec3d9 | 1773 | { |
a7538db1 JH |
1774 | smtp_transport_options_block * ob = |
1775 | (smtp_transport_options_block *)tb->options_block; | |
059ec3d9 | 1776 | static uschar txt[256]; |
868f5672 JH |
1777 | uschar * expciphers; |
1778 | X509 * server_cert; | |
059ec3d9 | 1779 | int rc; |
817d9f57 | 1780 | static uschar cipherbuf[256]; |
043b1248 JH |
1781 | |
1782 | #ifndef DISABLE_OCSP | |
043b1248 | 1783 | BOOL request_ocsp = FALSE; |
6634ac8d | 1784 | BOOL require_ocsp = FALSE; |
043b1248 JH |
1785 | #endif |
1786 | #ifdef EXPERIMENTAL_DANE | |
868f5672 JH |
1787 | dns_answer tlsa_dnsa; |
1788 | BOOL dane = FALSE; | |
1789 | BOOL dane_required; | |
043b1248 JH |
1790 | #endif |
1791 | ||
1792 | #ifdef EXPERIMENTAL_DANE | |
fde080a4 | 1793 | tls_out.dane_verified = FALSE; |
594706ea | 1794 | tls_out.tlsa_usage = 0; |
868f5672 JH |
1795 | dane_required = verify_check_this_host(&ob->hosts_require_dane, NULL, |
1796 | host->name, host->address, NULL) == OK; | |
868f5672 JH |
1797 | |
1798 | if (host->dnssec == DS_YES) | |
1799 | { | |
1800 | if( dane_required | |
1801 | || verify_check_this_host(&ob->hosts_try_dane, NULL, | |
1802 | host->name, host->address, NULL) == OK | |
1803 | ) | |
fde080a4 JH |
1804 | if ((rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK) |
1805 | return rc; | |
868f5672 | 1806 | } |
7a31d643 | 1807 | else if (dane_required) |
868f5672 | 1808 | { |
cf2b569e | 1809 | /*XXX a shame we only find this after making tcp & smtp connection */ |
b4161d10 | 1810 | /* move the test earlier? */ |
7a31d643 | 1811 | log_write(0, LOG_MAIN, "DANE error: previous lookup not DNSSEC"); |
868f5672 JH |
1812 | return FAIL; |
1813 | } | |
043b1248 JH |
1814 | #endif |
1815 | ||
f2de3a33 | 1816 | #ifndef DISABLE_OCSP |
043b1248 | 1817 | { |
fca41d5a JH |
1818 | if ((require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp, |
1819 | NULL, host->name, host->address, NULL) == OK)) | |
1820 | request_ocsp = TRUE; | |
1821 | else | |
1822 | { | |
1823 | # ifdef EXPERIMENTAL_DANE | |
1824 | if ( dane | |
1825 | && ob->hosts_request_ocsp[0] == '*' | |
1826 | && ob->hosts_request_ocsp[1] == '\0' | |
1827 | ) | |
1828 | { | |
1829 | /* Unchanged from default. Use a safer one under DANE */ | |
1830 | request_ocsp = TRUE; | |
1831 | ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} " | |
1832 | " {= {4}{$tls_out_tlsa_usage}} } " | |
1833 | " {*}{}}"; | |
1834 | } | |
1835 | else | |
1836 | # endif | |
1837 | request_ocsp = verify_check_this_host(&ob->hosts_request_ocsp, | |
1838 | NULL, host->name, host->address, NULL) == OK; | |
1839 | } | |
043b1248 | 1840 | } |
f5d78688 | 1841 | #endif |
059ec3d9 | 1842 | |
65867078 JH |
1843 | rc = tls_init(&client_ctx, host, NULL, |
1844 | ob->tls_certificate, ob->tls_privatekey, | |
f2de3a33 | 1845 | #ifndef DISABLE_OCSP |
44662487 | 1846 | (void *)(long)request_ocsp, |
3f7eeb86 | 1847 | #endif |
817d9f57 | 1848 | addr, &client_static_cbinfo); |
059ec3d9 PH |
1849 | if (rc != OK) return rc; |
1850 | ||
817d9f57 | 1851 | tls_out.certificate_verified = FALSE; |
a2ff477a | 1852 | client_verify_callback_called = FALSE; |
059ec3d9 | 1853 | |
65867078 JH |
1854 | if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers", |
1855 | &expciphers)) | |
059ec3d9 PH |
1856 | return FAIL; |
1857 | ||
1858 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
1859 | are separated by underscores. So that I can use either form in my tests, and | |
1860 | also for general convenience, we turn underscores into hyphens here. */ | |
1861 | ||
1862 | if (expciphers != NULL) | |
1863 | { | |
1864 | uschar *s = expciphers; | |
1865 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1866 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1867 | if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers)) |
7199e1ee | 1868 | return tls_error(US"SSL_CTX_set_cipher_list", host, NULL); |
059ec3d9 PH |
1869 | } |
1870 | ||
043b1248 | 1871 | #ifdef EXPERIMENTAL_DANE |
868f5672 | 1872 | if (dane) |
a63be306 | 1873 | { |
e5cccda9 JH |
1874 | SSL_CTX_set_verify(client_ctx, SSL_VERIFY_PEER, verify_callback_client_dane); |
1875 | ||
043b1248 | 1876 | if (!DANESSL_library_init()) |
b4161d10 | 1877 | return tls_error(US"library init", host, NULL); |
043b1248 | 1878 | if (DANESSL_CTX_init(client_ctx) <= 0) |
b4161d10 | 1879 | return tls_error(US"context init", host, NULL); |
043b1248 JH |
1880 | } |
1881 | else | |
e51c7be2 | 1882 | |
043b1248 JH |
1883 | #endif |
1884 | ||
1885 | if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob | |
e51c7be2 | 1886 | #ifdef EXPERIMENTAL_CERTNAMES |
043b1248 | 1887 | , client_static_cbinfo |
e51c7be2 | 1888 | #endif |
043b1248 | 1889 | )) != OK) |
65867078 | 1890 | return rc; |
059ec3d9 | 1891 | |
65867078 JH |
1892 | if ((client_ssl = SSL_new(client_ctx)) == NULL) |
1893 | return tls_error(US"SSL_new", host, NULL); | |
817d9f57 JH |
1894 | SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1895 | SSL_set_fd(client_ssl, fd); | |
1896 | SSL_set_connect_state(client_ssl); | |
059ec3d9 | 1897 | |
65867078 | 1898 | if (ob->tls_sni) |
3f0945ff | 1899 | { |
65867078 | 1900 | if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni)) |
3f0945ff | 1901 | return FAIL; |
ec4b68e5 | 1902 | if (tls_out.sni == NULL) |
2c9a0e86 PP |
1903 | { |
1904 | DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n"); | |
1905 | } | |
ec4b68e5 | 1906 | else if (!Ustrlen(tls_out.sni)) |
817d9f57 | 1907 | tls_out.sni = NULL; |
3f0945ff PP |
1908 | else |
1909 | { | |
35731706 | 1910 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 JH |
1911 | DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni); |
1912 | SSL_set_tlsext_host_name(client_ssl, tls_out.sni); | |
35731706 PP |
1913 | #else |
1914 | DEBUG(D_tls) | |
1915 | debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n", | |
02d9264f | 1916 | tls_out.sni); |
35731706 | 1917 | #endif |
3f0945ff PP |
1918 | } |
1919 | } | |
1920 | ||
594706ea JH |
1921 | #ifdef EXPERIMENTAL_DANE |
1922 | if (dane) | |
1923 | if ((rc = dane_tlsa_load(client_ssl, host, &tlsa_dnsa)) != OK) | |
1924 | return rc; | |
1925 | #endif | |
1926 | ||
f2de3a33 | 1927 | #ifndef DISABLE_OCSP |
f5d78688 JH |
1928 | /* Request certificate status at connection-time. If the server |
1929 | does OCSP stapling we will get the callback (set in tls_init()) */ | |
b50c8b84 | 1930 | # ifdef EXPERIMENTAL_DANE |
594706ea JH |
1931 | if (request_ocsp) |
1932 | { | |
1933 | const uschar * s; | |
1934 | if ( (s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage") | |
1935 | || (s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage") | |
1936 | ) | |
1937 | { /* Re-eval now $tls_out_tlsa_usage is populated. If | |
1938 | this means we avoid the OCSP request, we wasted the setup | |
1939 | cost in tls_init(). */ | |
1940 | require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp, | |
1941 | NULL, host->name, host->address, NULL) == OK; | |
1942 | request_ocsp = require_ocsp ? TRUE | |
1943 | : verify_check_this_host(&ob->hosts_request_ocsp, | |
1944 | NULL, host->name, host->address, NULL) == OK; | |
1945 | } | |
1946 | } | |
b50c8b84 JH |
1947 | # endif |
1948 | ||
44662487 JH |
1949 | if (request_ocsp) |
1950 | { | |
f5d78688 | 1951 | SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp); |
44662487 JH |
1952 | client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp; |
1953 | tls_out.ocsp = OCSP_NOT_RESP; | |
1954 | } | |
f5d78688 JH |
1955 | #endif |
1956 | ||
a7538db1 JH |
1957 | #ifdef EXPERIMENTAL_TPDA |
1958 | client_static_cbinfo->event_action = tb->tpda_event_action; | |
1959 | #endif | |
043b1248 | 1960 | |
059ec3d9 PH |
1961 | /* There doesn't seem to be a built-in timeout on connection. */ |
1962 | ||
1963 | DEBUG(D_tls) debug_printf("Calling SSL_connect\n"); | |
1964 | sigalrm_seen = FALSE; | |
65867078 | 1965 | alarm(ob->command_timeout); |
817d9f57 | 1966 | rc = SSL_connect(client_ssl); |
059ec3d9 PH |
1967 | alarm(0); |
1968 | ||
043b1248 | 1969 | #ifdef EXPERIMENTAL_DANE |
12ee8cf9 | 1970 | if (dane) |
fde080a4 | 1971 | DANESSL_cleanup(client_ssl); |
043b1248 JH |
1972 | #endif |
1973 | ||
059ec3d9 | 1974 | if (rc <= 0) |
7199e1ee | 1975 | return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL); |
059ec3d9 PH |
1976 | |
1977 | DEBUG(D_tls) debug_printf("SSL_connect succeeded\n"); | |
1978 | ||
453a6645 | 1979 | /* Beware anonymous ciphers which lead to server_cert being NULL */ |
9d1c15ef | 1980 | /*XXX server_cert is never freed... use X509_free() */ |
817d9f57 | 1981 | server_cert = SSL_get_peer_certificate (client_ssl); |
453a6645 PP |
1982 | if (server_cert) |
1983 | { | |
817d9f57 | 1984 | tls_out.peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert), |
453a6645 | 1985 | CS txt, sizeof(txt)); |
9d1c15ef | 1986 | tls_out.peerdn = txt; /*XXX a static buffer... */ |
453a6645 PP |
1987 | } |
1988 | else | |
817d9f57 | 1989 | tls_out.peerdn = NULL; |
059ec3d9 | 1990 | |
817d9f57 JH |
1991 | construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits); |
1992 | tls_out.cipher = cipherbuf; | |
059ec3d9 | 1993 | |
9d1c15ef JH |
1994 | /* Record the certificate we presented */ |
1995 | { | |
1996 | X509 * crt = SSL_get_certificate(client_ssl); | |
1997 | tls_out.ourcert = crt ? X509_dup(crt) : NULL; | |
1998 | } | |
1999 | ||
817d9f57 | 2000 | tls_out.active = fd; |
059ec3d9 PH |
2001 | return OK; |
2002 | } | |
2003 | ||
2004 | ||
2005 | ||
2006 | ||
2007 | ||
2008 | /************************************************* | |
2009 | * TLS version of getc * | |
2010 | *************************************************/ | |
2011 | ||
2012 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
2013 | it refills the buffer via the SSL reading function. | |
2014 | ||
2015 | Arguments: none | |
2016 | Returns: the next character or EOF | |
817d9f57 JH |
2017 | |
2018 | Only used by the server-side TLS. | |
059ec3d9 PH |
2019 | */ |
2020 | ||
2021 | int | |
2022 | tls_getc(void) | |
2023 | { | |
2024 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) | |
2025 | { | |
2026 | int error; | |
2027 | int inbytes; | |
2028 | ||
817d9f57 | 2029 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl, |
c80c5570 | 2030 | ssl_xfer_buffer, ssl_xfer_buffer_size); |
059ec3d9 PH |
2031 | |
2032 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 JH |
2033 | inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size); |
2034 | error = SSL_get_error(server_ssl, inbytes); | |
059ec3d9 PH |
2035 | alarm(0); |
2036 | ||
2037 | /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been | |
2038 | closed down, not that the socket itself has been closed down. Revert to | |
2039 | non-SSL handling. */ | |
2040 | ||
2041 | if (error == SSL_ERROR_ZERO_RETURN) | |
2042 | { | |
2043 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2044 | ||
2045 | receive_getc = smtp_getc; | |
2046 | receive_ungetc = smtp_ungetc; | |
2047 | receive_feof = smtp_feof; | |
2048 | receive_ferror = smtp_ferror; | |
58eb016e | 2049 | receive_smtp_buffered = smtp_buffered; |
059ec3d9 | 2050 | |
817d9f57 JH |
2051 | SSL_free(server_ssl); |
2052 | server_ssl = NULL; | |
2053 | tls_in.active = -1; | |
2054 | tls_in.bits = 0; | |
2055 | tls_in.cipher = NULL; | |
2056 | tls_in.peerdn = NULL; | |
2057 | tls_in.sni = NULL; | |
059ec3d9 PH |
2058 | |
2059 | return smtp_getc(); | |
2060 | } | |
2061 | ||
2062 | /* Handle genuine errors */ | |
2063 | ||
ba084640 PP |
2064 | else if (error == SSL_ERROR_SSL) |
2065 | { | |
2066 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
89dd51cd | 2067 | log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); |
ba084640 PP |
2068 | ssl_xfer_error = 1; |
2069 | return EOF; | |
2070 | } | |
2071 | ||
059ec3d9 PH |
2072 | else if (error != SSL_ERROR_NONE) |
2073 | { | |
2074 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
2075 | ssl_xfer_error = 1; | |
2076 | return EOF; | |
2077 | } | |
c80c5570 | 2078 | |
80a47a2c TK |
2079 | #ifndef DISABLE_DKIM |
2080 | dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); | |
2081 | #endif | |
059ec3d9 PH |
2082 | ssl_xfer_buffer_hwm = inbytes; |
2083 | ssl_xfer_buffer_lwm = 0; | |
2084 | } | |
2085 | ||
2086 | /* Something in the buffer; return next uschar */ | |
2087 | ||
2088 | return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; | |
2089 | } | |
2090 | ||
2091 | ||
2092 | ||
2093 | /************************************************* | |
2094 | * Read bytes from TLS channel * | |
2095 | *************************************************/ | |
2096 | ||
2097 | /* | |
2098 | Arguments: | |
2099 | buff buffer of data | |
2100 | len size of buffer | |
2101 | ||
2102 | Returns: the number of bytes read | |
2103 | -1 after a failed read | |
817d9f57 JH |
2104 | |
2105 | Only used by the client-side TLS. | |
059ec3d9 PH |
2106 | */ |
2107 | ||
2108 | int | |
389ca47a | 2109 | tls_read(BOOL is_server, uschar *buff, size_t len) |
059ec3d9 | 2110 | { |
389ca47a | 2111 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 PH |
2112 | int inbytes; |
2113 | int error; | |
2114 | ||
389ca47a | 2115 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl, |
c80c5570 | 2116 | buff, (unsigned int)len); |
059ec3d9 | 2117 | |
389ca47a JH |
2118 | inbytes = SSL_read(ssl, CS buff, len); |
2119 | error = SSL_get_error(ssl, inbytes); | |
059ec3d9 PH |
2120 | |
2121 | if (error == SSL_ERROR_ZERO_RETURN) | |
2122 | { | |
2123 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2124 | return -1; | |
2125 | } | |
2126 | else if (error != SSL_ERROR_NONE) | |
2127 | { | |
2128 | return -1; | |
2129 | } | |
2130 | ||
2131 | return inbytes; | |
2132 | } | |
2133 | ||
2134 | ||
2135 | ||
2136 | ||
2137 | ||
2138 | /************************************************* | |
2139 | * Write bytes down TLS channel * | |
2140 | *************************************************/ | |
2141 | ||
2142 | /* | |
2143 | Arguments: | |
817d9f57 | 2144 | is_server channel specifier |
059ec3d9 PH |
2145 | buff buffer of data |
2146 | len number of bytes | |
2147 | ||
2148 | Returns: the number of bytes after a successful write, | |
2149 | -1 after a failed write | |
817d9f57 JH |
2150 | |
2151 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2152 | */ |
2153 | ||
2154 | int | |
817d9f57 | 2155 | tls_write(BOOL is_server, const uschar *buff, size_t len) |
059ec3d9 PH |
2156 | { |
2157 | int outbytes; | |
2158 | int error; | |
2159 | int left = len; | |
817d9f57 | 2160 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 | 2161 | |
c80c5570 | 2162 | DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left); |
059ec3d9 PH |
2163 | while (left > 0) |
2164 | { | |
c80c5570 | 2165 | DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left); |
059ec3d9 PH |
2166 | outbytes = SSL_write(ssl, CS buff, left); |
2167 | error = SSL_get_error(ssl, outbytes); | |
2168 | DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error); | |
2169 | switch (error) | |
2170 | { | |
2171 | case SSL_ERROR_SSL: | |
2172 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2173 | log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); | |
2174 | return -1; | |
2175 | ||
2176 | case SSL_ERROR_NONE: | |
2177 | left -= outbytes; | |
2178 | buff += outbytes; | |
2179 | break; | |
2180 | ||
2181 | case SSL_ERROR_ZERO_RETURN: | |
2182 | log_write(0, LOG_MAIN, "SSL channel closed on write"); | |
2183 | return -1; | |
2184 | ||
817d9f57 JH |
2185 | case SSL_ERROR_SYSCALL: |
2186 | log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", | |
2187 | sender_fullhost ? sender_fullhost : US"<unknown>", | |
2188 | strerror(errno)); | |
2189 | ||
059ec3d9 PH |
2190 | default: |
2191 | log_write(0, LOG_MAIN, "SSL_write error %d", error); | |
2192 | return -1; | |
2193 | } | |
2194 | } | |
2195 | return len; | |
2196 | } | |
2197 | ||
2198 | ||
2199 | ||
2200 | /************************************************* | |
2201 | * Close down a TLS session * | |
2202 | *************************************************/ | |
2203 | ||
2204 | /* This is also called from within a delivery subprocess forked from the | |
2205 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
2206 | would tamper with the SSL session in the parent process). | |
2207 | ||
2208 | Arguments: TRUE if SSL_shutdown is to be called | |
2209 | Returns: nothing | |
817d9f57 JH |
2210 | |
2211 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2212 | */ |
2213 | ||
2214 | void | |
817d9f57 | 2215 | tls_close(BOOL is_server, BOOL shutdown) |
059ec3d9 | 2216 | { |
817d9f57 | 2217 | SSL **sslp = is_server ? &server_ssl : &client_ssl; |
389ca47a | 2218 | int *fdp = is_server ? &tls_in.active : &tls_out.active; |
817d9f57 JH |
2219 | |
2220 | if (*fdp < 0) return; /* TLS was not active */ | |
059ec3d9 PH |
2221 | |
2222 | if (shutdown) | |
2223 | { | |
2224 | DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n"); | |
817d9f57 | 2225 | SSL_shutdown(*sslp); |
059ec3d9 PH |
2226 | } |
2227 | ||
817d9f57 JH |
2228 | SSL_free(*sslp); |
2229 | *sslp = NULL; | |
059ec3d9 | 2230 | |
817d9f57 | 2231 | *fdp = -1; |
059ec3d9 PH |
2232 | } |
2233 | ||
36f12725 NM |
2234 | |
2235 | ||
2236 | ||
3375e053 PP |
2237 | /************************************************* |
2238 | * Let tls_require_ciphers be checked at startup * | |
2239 | *************************************************/ | |
2240 | ||
2241 | /* The tls_require_ciphers option, if set, must be something which the | |
2242 | library can parse. | |
2243 | ||
2244 | Returns: NULL on success, or error message | |
2245 | */ | |
2246 | ||
2247 | uschar * | |
2248 | tls_validate_require_cipher(void) | |
2249 | { | |
2250 | SSL_CTX *ctx; | |
2251 | uschar *s, *expciphers, *err; | |
2252 | ||
2253 | /* this duplicates from tls_init(), we need a better "init just global | |
2254 | state, for no specific purpose" singleton function of our own */ | |
2255 | ||
2256 | SSL_load_error_strings(); | |
2257 | OpenSSL_add_ssl_algorithms(); | |
2258 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
2259 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the | |
2260 | list of available digests. */ | |
2261 | EVP_add_digest(EVP_sha256()); | |
2262 | #endif | |
2263 | ||
2264 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
2265 | return NULL; | |
2266 | ||
2267 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers)) | |
2268 | return US"failed to expand tls_require_ciphers"; | |
2269 | ||
2270 | if (!(expciphers && *expciphers)) | |
2271 | return NULL; | |
2272 | ||
2273 | /* normalisation ripped from above */ | |
2274 | s = expciphers; | |
2275 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
2276 | ||
2277 | err = NULL; | |
2278 | ||
2279 | ctx = SSL_CTX_new(SSLv23_server_method()); | |
2280 | if (!ctx) | |
2281 | { | |
2282 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2283 | return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring); | |
2284 | } | |
2285 | ||
2286 | DEBUG(D_tls) | |
2287 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
2288 | ||
2289 | if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) | |
2290 | { | |
2291 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2292 | err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers); | |
2293 | } | |
2294 | ||
2295 | SSL_CTX_free(ctx); | |
2296 | ||
2297 | return err; | |
2298 | } | |
2299 | ||
2300 | ||
2301 | ||
2302 | ||
36f12725 NM |
2303 | /************************************************* |
2304 | * Report the library versions. * | |
2305 | *************************************************/ | |
2306 | ||
2307 | /* There have historically been some issues with binary compatibility in | |
2308 | OpenSSL libraries; if Exim (like many other applications) is built against | |
2309 | one version of OpenSSL but the run-time linker picks up another version, | |
2310 | it can result in serious failures, including crashing with a SIGSEGV. So | |
2311 | report the version found by the compiler and the run-time version. | |
2312 | ||
f64a1e23 PP |
2313 | Note: some OS vendors backport security fixes without changing the version |
2314 | number/string, and the version date remains unchanged. The _build_ date | |
2315 | will change, so we can more usefully assist with version diagnosis by also | |
2316 | reporting the build date. | |
2317 | ||
36f12725 NM |
2318 | Arguments: a FILE* to print the results to |
2319 | Returns: nothing | |
2320 | */ | |
2321 | ||
2322 | void | |
2323 | tls_version_report(FILE *f) | |
2324 | { | |
754a0503 | 2325 | fprintf(f, "Library version: OpenSSL: Compile: %s\n" |
f64a1e23 PP |
2326 | " Runtime: %s\n" |
2327 | " : %s\n", | |
754a0503 | 2328 | OPENSSL_VERSION_TEXT, |
f64a1e23 PP |
2329 | SSLeay_version(SSLEAY_VERSION), |
2330 | SSLeay_version(SSLEAY_BUILT_ON)); | |
2331 | /* third line is 38 characters for the %s and the line is 73 chars long; | |
2332 | the OpenSSL output includes a "built on: " prefix already. */ | |
36f12725 NM |
2333 | } |
2334 | ||
9e3331ea TK |
2335 | |
2336 | ||
2337 | ||
2338 | /************************************************* | |
17c76198 | 2339 | * Random number generation * |
9e3331ea TK |
2340 | *************************************************/ |
2341 | ||
2342 | /* Pseudo-random number generation. The result is not expected to be | |
2343 | cryptographically strong but not so weak that someone will shoot themselves | |
2344 | in the foot using it as a nonce in input in some email header scheme or | |
2345 | whatever weirdness they'll twist this into. The result should handle fork() | |
2346 | and avoid repeating sequences. OpenSSL handles that for us. | |
2347 | ||
2348 | Arguments: | |
2349 | max range maximum | |
2350 | Returns a random number in range [0, max-1] | |
2351 | */ | |
2352 | ||
2353 | int | |
17c76198 | 2354 | vaguely_random_number(int max) |
9e3331ea TK |
2355 | { |
2356 | unsigned int r; | |
2357 | int i, needed_len; | |
de6135a0 PP |
2358 | static pid_t pidlast = 0; |
2359 | pid_t pidnow; | |
9e3331ea TK |
2360 | uschar *p; |
2361 | uschar smallbuf[sizeof(r)]; | |
2362 | ||
2363 | if (max <= 1) | |
2364 | return 0; | |
2365 | ||
de6135a0 PP |
2366 | pidnow = getpid(); |
2367 | if (pidnow != pidlast) | |
2368 | { | |
2369 | /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state | |
2370 | is unique for each thread", this doesn't apparently apply across processes, | |
2371 | so our own warning from vaguely_random_number_fallback() applies here too. | |
2372 | Fix per PostgreSQL. */ | |
2373 | if (pidlast != 0) | |
2374 | RAND_cleanup(); | |
2375 | pidlast = pidnow; | |
2376 | } | |
2377 | ||
9e3331ea TK |
2378 | /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ |
2379 | if (!RAND_status()) | |
2380 | { | |
2381 | randstuff r; | |
2382 | gettimeofday(&r.tv, NULL); | |
2383 | r.p = getpid(); | |
2384 | ||
2385 | RAND_seed((uschar *)(&r), sizeof(r)); | |
2386 | } | |
2387 | /* We're after pseudo-random, not random; if we still don't have enough data | |
2388 | in the internal PRNG then our options are limited. We could sleep and hope | |
2389 | for entropy to come along (prayer technique) but if the system is so depleted | |
2390 | in the first place then something is likely to just keep taking it. Instead, | |
2391 | we'll just take whatever little bit of pseudo-random we can still manage to | |
2392 | get. */ | |
2393 | ||
2394 | needed_len = sizeof(r); | |
2395 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
2396 | asked for a number less than 10. */ | |
2397 | for (r = max, i = 0; r; ++i) | |
2398 | r >>= 1; | |
2399 | i = (i + 7) / 8; | |
2400 | if (i < needed_len) | |
2401 | needed_len = i; | |
2402 | ||
2403 | /* We do not care if crypto-strong */ | |
17c76198 PP |
2404 | i = RAND_pseudo_bytes(smallbuf, needed_len); |
2405 | if (i < 0) | |
2406 | { | |
2407 | DEBUG(D_all) | |
2408 | debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n"); | |
2409 | return vaguely_random_number_fallback(max); | |
2410 | } | |
2411 | ||
9e3331ea TK |
2412 | r = 0; |
2413 | for (p = smallbuf; needed_len; --needed_len, ++p) | |
2414 | { | |
2415 | r *= 256; | |
2416 | r += *p; | |
2417 | } | |
2418 | ||
2419 | /* We don't particularly care about weighted results; if someone wants | |
2420 | smooth distribution and cares enough then they should submit a patch then. */ | |
2421 | return r % max; | |
2422 | } | |
2423 | ||
77bb000f PP |
2424 | |
2425 | ||
2426 | ||
2427 | /************************************************* | |
2428 | * OpenSSL option parse * | |
2429 | *************************************************/ | |
2430 | ||
2431 | /* Parse one option for tls_openssl_options_parse below | |
2432 | ||
2433 | Arguments: | |
2434 | name one option name | |
2435 | value place to store a value for it | |
2436 | Returns success or failure in parsing | |
2437 | */ | |
2438 | ||
2439 | struct exim_openssl_option { | |
2440 | uschar *name; | |
2441 | long value; | |
2442 | }; | |
2443 | /* We could use a macro to expand, but we need the ifdef and not all the | |
2444 | options document which version they were introduced in. Policylet: include | |
2445 | all options unless explicitly for DTLS, let the administrator choose which | |
2446 | to apply. | |
2447 | ||
2448 | This list is current as of: | |
e2fbf4a2 PP |
2449 | ==> 1.0.1b <== |
2450 | Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev | |
2451 | */ | |
77bb000f PP |
2452 | static struct exim_openssl_option exim_openssl_options[] = { |
2453 | /* KEEP SORTED ALPHABETICALLY! */ | |
2454 | #ifdef SSL_OP_ALL | |
73a46702 | 2455 | { US"all", SSL_OP_ALL }, |
77bb000f PP |
2456 | #endif |
2457 | #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION | |
73a46702 | 2458 | { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, |
77bb000f PP |
2459 | #endif |
2460 | #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE | |
73a46702 | 2461 | { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, |
77bb000f PP |
2462 | #endif |
2463 | #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS | |
73a46702 | 2464 | { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, |
77bb000f PP |
2465 | #endif |
2466 | #ifdef SSL_OP_EPHEMERAL_RSA | |
73a46702 | 2467 | { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, |
77bb000f PP |
2468 | #endif |
2469 | #ifdef SSL_OP_LEGACY_SERVER_CONNECT | |
73a46702 | 2470 | { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, |
77bb000f PP |
2471 | #endif |
2472 | #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER | |
73a46702 | 2473 | { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, |
77bb000f PP |
2474 | #endif |
2475 | #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG | |
73a46702 | 2476 | { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, |
77bb000f PP |
2477 | #endif |
2478 | #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING | |
73a46702 | 2479 | { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, |
77bb000f PP |
2480 | #endif |
2481 | #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG | |
73a46702 | 2482 | { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, |
77bb000f PP |
2483 | #endif |
2484 | #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG | |
73a46702 | 2485 | { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, |
77bb000f | 2486 | #endif |
c80c5570 PP |
2487 | #ifdef SSL_OP_NO_COMPRESSION |
2488 | { US"no_compression", SSL_OP_NO_COMPRESSION }, | |
2489 | #endif | |
77bb000f | 2490 | #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |
73a46702 | 2491 | { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, |
77bb000f | 2492 | #endif |
c0c7b2da PP |
2493 | #ifdef SSL_OP_NO_SSLv2 |
2494 | { US"no_sslv2", SSL_OP_NO_SSLv2 }, | |
2495 | #endif | |
2496 | #ifdef SSL_OP_NO_SSLv3 | |
2497 | { US"no_sslv3", SSL_OP_NO_SSLv3 }, | |
2498 | #endif | |
2499 | #ifdef SSL_OP_NO_TICKET | |
2500 | { US"no_ticket", SSL_OP_NO_TICKET }, | |
2501 | #endif | |
2502 | #ifdef SSL_OP_NO_TLSv1 | |
2503 | { US"no_tlsv1", SSL_OP_NO_TLSv1 }, | |
2504 | #endif | |
c80c5570 PP |
2505 | #ifdef SSL_OP_NO_TLSv1_1 |
2506 | #if SSL_OP_NO_TLSv1_1 == 0x00000400L | |
2507 | /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */ | |
2508 | #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring | |
2509 | #else | |
2510 | { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 }, | |
2511 | #endif | |
2512 | #endif | |
2513 | #ifdef SSL_OP_NO_TLSv1_2 | |
2514 | { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 }, | |
2515 | #endif | |
e2fbf4a2 PP |
2516 | #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG |
2517 | { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG }, | |
2518 | #endif | |
77bb000f | 2519 | #ifdef SSL_OP_SINGLE_DH_USE |
73a46702 | 2520 | { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, |
77bb000f PP |
2521 | #endif |
2522 | #ifdef SSL_OP_SINGLE_ECDH_USE | |
73a46702 | 2523 | { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, |
77bb000f PP |
2524 | #endif |
2525 | #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG | |
73a46702 | 2526 | { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, |
77bb000f PP |
2527 | #endif |
2528 | #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG | |
73a46702 | 2529 | { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, |
77bb000f PP |
2530 | #endif |
2531 | #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG | |
73a46702 | 2532 | { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, |
77bb000f PP |
2533 | #endif |
2534 | #ifdef SSL_OP_TLS_D5_BUG | |
73a46702 | 2535 | { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, |
77bb000f PP |
2536 | #endif |
2537 | #ifdef SSL_OP_TLS_ROLLBACK_BUG | |
73a46702 | 2538 | { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, |
77bb000f PP |
2539 | #endif |
2540 | }; | |
2541 | static int exim_openssl_options_size = | |
2542 | sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option); | |
2543 | ||
c80c5570 | 2544 | |
77bb000f PP |
2545 | static BOOL |
2546 | tls_openssl_one_option_parse(uschar *name, long *value) | |
2547 | { | |
2548 | int first = 0; | |
2549 | int last = exim_openssl_options_size; | |
2550 | while (last > first) | |
2551 | { | |
2552 | int middle = (first + last)/2; | |
2553 | int c = Ustrcmp(name, exim_openssl_options[middle].name); | |
2554 | if (c == 0) | |
2555 | { | |
2556 | *value = exim_openssl_options[middle].value; | |
2557 | return TRUE; | |
2558 | } | |
2559 | else if (c > 0) | |
2560 | first = middle + 1; | |
2561 | else | |
2562 | last = middle; | |
2563 | } | |
2564 | return FALSE; | |
2565 | } | |
2566 | ||
2567 | ||
2568 | ||
2569 | ||
2570 | /************************************************* | |
2571 | * OpenSSL option parsing logic * | |
2572 | *************************************************/ | |
2573 | ||
2574 | /* OpenSSL has a number of compatibility options which an administrator might | |
2575 | reasonably wish to set. Interpret a list similarly to decode_bits(), so that | |
2576 | we look like log_selector. | |
2577 | ||
2578 | Arguments: | |
2579 | option_spec the administrator-supplied string of options | |
2580 | results ptr to long storage for the options bitmap | |
2581 | Returns success or failure | |
2582 | */ | |
2583 | ||
2584 | BOOL | |
2585 | tls_openssl_options_parse(uschar *option_spec, long *results) | |
2586 | { | |
2587 | long result, item; | |
2588 | uschar *s, *end; | |
2589 | uschar keep_c; | |
2590 | BOOL adding, item_parsed; | |
2591 | ||
0e944a0d | 2592 | result = 0L; |
b1770b6e | 2593 | /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed |
da3ad30d | 2594 | * from default because it increases BEAST susceptibility. */ |
f0f5a555 PP |
2595 | #ifdef SSL_OP_NO_SSLv2 |
2596 | result |= SSL_OP_NO_SSLv2; | |
2597 | #endif | |
77bb000f PP |
2598 | |
2599 | if (option_spec == NULL) | |
2600 | { | |
2601 | *results = result; | |
2602 | return TRUE; | |
2603 | } | |
2604 | ||
2605 | for (s=option_spec; *s != '\0'; /**/) | |
2606 | { | |
2607 | while (isspace(*s)) ++s; | |
2608 | if (*s == '\0') | |
2609 | break; | |
2610 | if (*s != '+' && *s != '-') | |
2611 | { | |
2612 | DEBUG(D_tls) debug_printf("malformed openssl option setting: " | |
0e944a0d | 2613 | "+ or - expected but found \"%s\"\n", s); |
77bb000f PP |
2614 | return FALSE; |
2615 | } | |
2616 | adding = *s++ == '+'; | |
2617 | for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; | |
2618 | keep_c = *end; | |
2619 | *end = '\0'; | |
2620 | item_parsed = tls_openssl_one_option_parse(s, &item); | |
2621 | if (!item_parsed) | |
2622 | { | |
0e944a0d | 2623 | DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); |
77bb000f PP |
2624 | return FALSE; |
2625 | } | |
2626 | DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n", | |
2627 | adding ? "adding" : "removing", result, item, s); | |
2628 | if (adding) | |
2629 | result |= item; | |
2630 | else | |
2631 | result &= ~item; | |
2632 | *end = keep_c; | |
2633 | s = end; | |
2634 | } | |
2635 | ||
2636 | *results = result; | |
2637 | return TRUE; | |
2638 | } | |
2639 | ||
9d1c15ef JH |
2640 | /* vi: aw ai sw=2 |
2641 | */ | |
059ec3d9 | 2642 | /* End of tls-openssl.c */ |