Commit | Line | Data |
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059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
80fea873 | 5 | /* Copyright (c) University of Cambridge 1995 - 2016 */ |
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> | |
10ca4f1c JH |
25 | #ifndef OPENSSL_NO_ECDH |
26 | # include <openssl/ec.h> | |
27 | #endif | |
f2de3a33 | 28 | #ifndef DISABLE_OCSP |
e51c7be2 | 29 | # include <openssl/ocsp.h> |
3f7eeb86 | 30 | #endif |
85098ee7 JH |
31 | #ifdef EXPERIMENTAL_DANE |
32 | # include <danessl.h> | |
33 | #endif | |
34 | ||
3f7eeb86 | 35 | |
f2de3a33 JH |
36 | #ifndef DISABLE_OCSP |
37 | # define EXIM_OCSP_SKEW_SECONDS (300L) | |
38 | # define EXIM_OCSP_MAX_AGE (-1L) | |
3f7eeb86 | 39 | #endif |
059ec3d9 | 40 | |
3bcbbbe2 | 41 | #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT) |
e51c7be2 | 42 | # define EXIM_HAVE_OPENSSL_TLSEXT |
3bcbbbe2 | 43 | #endif |
c8dfb21d JH |
44 | #if OPENSSL_VERSION_NUMBER >= 0x00908000L |
45 | # define EXIM_HAVE_RSA_GENKEY_EX | |
46 | #endif | |
47 | #if OPENSSL_VERSION_NUMBER >= 0x10100000L | |
48 | # define EXIM_HAVE_OCSP_RESP_COUNT | |
49 | #else | |
50 | # define EXIM_HAVE_EPHEM_RSA_KEX | |
51 | # define EXIM_HAVE_RAND_PSEUDO | |
52 | #endif | |
53 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
54 | # define EXIM_HAVE_SHA256 | |
55 | #endif | |
34e3241d PP |
56 | |
57 | /* | |
58 | * X509_check_host provides sane certificate hostname checking, but was added | |
59 | * to OpenSSL late, after other projects forked off the code-base. So in | |
60 | * addition to guarding against the base version number, beware that LibreSSL | |
61 | * does not (at this time) support this function. | |
62 | * | |
63 | * If LibreSSL gains a different API, perhaps via libtls, then we'll probably | |
64 | * opt to disentangle and ask a LibreSSL user to provide glue for a third | |
65 | * crypto provider for libtls instead of continuing to tie the OpenSSL glue | |
66 | * into even twistier knots. If LibreSSL gains the same API, we can just | |
67 | * change this guard and punt the issue for a while longer. | |
68 | */ | |
69 | #ifndef LIBRESSL_VERSION_NUMBER | |
70 | # if OPENSSL_VERSION_NUMBER >= 0x010100000L | |
71 | # define EXIM_HAVE_OPENSSL_CHECKHOST | |
72 | # endif | |
73 | # if OPENSSL_VERSION_NUMBER >= 0x010000000L \ | |
2dfb468b | 74 | && (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L |
34e3241d PP |
75 | # define EXIM_HAVE_OPENSSL_CHECKHOST |
76 | # endif | |
11aa88b0 | 77 | #endif |
10ca4f1c | 78 | |
11aa88b0 RA |
79 | #if !defined(LIBRESSL_VERSION_NUMBER) \ |
80 | || LIBRESSL_VERSION_NUMBER >= 0x20010000L | |
10ca4f1c JH |
81 | # if !defined(OPENSSL_NO_ECDH) |
82 | # if OPENSSL_VERSION_NUMBER >= 0x0090800fL | |
83 | # define EXIM_HAVE_ECDH | |
84 | # endif | |
85 | # if OPENSSL_VERSION_NUMBER >= 0x10002000L | |
c8dfb21d JH |
86 | # if OPENSSL_VERSION_NUMBER < 0x10100000L |
87 | # define EXIM_HAVE_OPENSSL_ECDH_AUTO | |
88 | # endif | |
10ca4f1c JH |
89 | # define EXIM_HAVE_OPENSSL_EC_NIST2NID |
90 | # endif | |
91 | # endif | |
2dfb468b | 92 | #endif |
3bcbbbe2 | 93 | |
67791ce4 JH |
94 | #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP) |
95 | # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile" | |
96 | # define DISABLE_OCSP | |
97 | #endif | |
98 | ||
059ec3d9 PH |
99 | /* Structure for collecting random data for seeding. */ |
100 | ||
101 | typedef struct randstuff { | |
9e3331ea TK |
102 | struct timeval tv; |
103 | pid_t p; | |
059ec3d9 PH |
104 | } randstuff; |
105 | ||
106 | /* Local static variables */ | |
107 | ||
a2ff477a JH |
108 | static BOOL client_verify_callback_called = FALSE; |
109 | static BOOL server_verify_callback_called = FALSE; | |
059ec3d9 PH |
110 | static const uschar *sid_ctx = US"exim"; |
111 | ||
d4f09789 PP |
112 | /* We have three different contexts to care about. |
113 | ||
114 | Simple case: client, `client_ctx` | |
115 | As a client, we can be doing a callout or cut-through delivery while receiving | |
116 | a message. So we have a client context, which should have options initialised | |
117 | from the SMTP Transport. | |
118 | ||
119 | Server: | |
120 | There are two cases: with and without ServerNameIndication from the client. | |
121 | Given TLS SNI, we can be using different keys, certs and various other | |
122 | configuration settings, because they're re-expanded with $tls_sni set. This | |
123 | allows vhosting with TLS. This SNI is sent in the handshake. | |
124 | A client might not send SNI, so we need a fallback, and an initial setup too. | |
125 | So as a server, we start out using `server_ctx`. | |
126 | If SNI is sent by the client, then we as server, mid-negotiation, try to clone | |
127 | `server_sni` from `server_ctx` and then initialise settings by re-expanding | |
128 | configuration. | |
129 | */ | |
130 | ||
817d9f57 JH |
131 | static SSL_CTX *client_ctx = NULL; |
132 | static SSL_CTX *server_ctx = NULL; | |
133 | static SSL *client_ssl = NULL; | |
134 | static SSL *server_ssl = NULL; | |
389ca47a | 135 | |
35731706 | 136 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 | 137 | static SSL_CTX *server_sni = NULL; |
35731706 | 138 | #endif |
059ec3d9 PH |
139 | |
140 | static char ssl_errstring[256]; | |
141 | ||
142 | static int ssl_session_timeout = 200; | |
a2ff477a JH |
143 | static BOOL client_verify_optional = FALSE; |
144 | static BOOL server_verify_optional = FALSE; | |
059ec3d9 | 145 | |
f5d78688 | 146 | static BOOL reexpand_tls_files_for_sni = FALSE; |
059ec3d9 PH |
147 | |
148 | ||
7be682ca PP |
149 | typedef struct tls_ext_ctx_cb { |
150 | uschar *certificate; | |
151 | uschar *privatekey; | |
f2de3a33 | 152 | #ifndef DISABLE_OCSP |
f5d78688 JH |
153 | BOOL is_server; |
154 | union { | |
155 | struct { | |
156 | uschar *file; | |
157 | uschar *file_expanded; | |
158 | OCSP_RESPONSE *response; | |
159 | } server; | |
160 | struct { | |
44662487 JH |
161 | X509_STORE *verify_store; /* non-null if status requested */ |
162 | BOOL verify_required; | |
f5d78688 JH |
163 | } client; |
164 | } u_ocsp; | |
3f7eeb86 | 165 | #endif |
7be682ca PP |
166 | uschar *dhparam; |
167 | /* these are cached from first expand */ | |
168 | uschar *server_cipher_list; | |
169 | /* only passed down to tls_error: */ | |
170 | host_item *host; | |
55414b25 | 171 | const uschar * verify_cert_hostnames; |
0cbf2b82 | 172 | #ifndef DISABLE_EVENT |
a7538db1 JH |
173 | uschar * event_action; |
174 | #endif | |
7be682ca PP |
175 | } tls_ext_ctx_cb; |
176 | ||
177 | /* should figure out a cleanup of API to handle state preserved per | |
178 | implementation, for various reasons, which can be void * in the APIs. | |
179 | For now, we hack around it. */ | |
817d9f57 JH |
180 | tls_ext_ctx_cb *client_static_cbinfo = NULL; |
181 | tls_ext_ctx_cb *server_static_cbinfo = NULL; | |
7be682ca PP |
182 | |
183 | static int | |
983207c1 JH |
184 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
185 | int (*cert_vfy_cb)(int, X509_STORE_CTX *) ); | |
059ec3d9 | 186 | |
3f7eeb86 | 187 | /* Callbacks */ |
3bcbbbe2 | 188 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
3f7eeb86 | 189 | static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg); |
3bcbbbe2 | 190 | #endif |
f2de3a33 | 191 | #ifndef DISABLE_OCSP |
f5d78688 | 192 | static int tls_server_stapling_cb(SSL *s, void *arg); |
3f7eeb86 PP |
193 | #endif |
194 | ||
059ec3d9 PH |
195 | |
196 | /************************************************* | |
197 | * Handle TLS error * | |
198 | *************************************************/ | |
199 | ||
200 | /* Called from lots of places when errors occur before actually starting to do | |
201 | the TLS handshake, that is, while the session is still in clear. Always returns | |
202 | DEFER for a server and FAIL for a client so that most calls can use "return | |
203 | tls_error(...)" to do this processing and then give an appropriate return. A | |
204 | single function is used for both server and client, because it is called from | |
205 | some shared functions. | |
206 | ||
207 | Argument: | |
208 | prefix text to include in the logged error | |
209 | host NULL if setting up a server; | |
210 | the connected host if setting up a client | |
7199e1ee | 211 | msg error message or NULL if we should ask OpenSSL |
059ec3d9 PH |
212 | |
213 | Returns: OK/DEFER/FAIL | |
214 | */ | |
215 | ||
216 | static int | |
23bb6982 | 217 | tls_error(uschar * prefix, const host_item * host, uschar * msg) |
059ec3d9 | 218 | { |
c562fd30 | 219 | if (!msg) |
7199e1ee TF |
220 | { |
221 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
5ca6d115 | 222 | msg = (uschar *)ssl_errstring; |
7199e1ee TF |
223 | } |
224 | ||
c562fd30 JH |
225 | if (host) |
226 | { | |
227 | log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection (%s): %s", | |
228 | host->name, host->address, prefix, msg); | |
229 | return FAIL; | |
230 | } | |
231 | else | |
059ec3d9 | 232 | { |
7199e1ee | 233 | uschar *conn_info = smtp_get_connection_info(); |
5ca6d115 | 234 | if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) |
7199e1ee | 235 | conn_info += 5; |
c562fd30 | 236 | /* I'd like to get separated H= here, but too hard for now */ |
7199e1ee TF |
237 | log_write(0, LOG_MAIN, "TLS error on %s (%s): %s", |
238 | conn_info, prefix, msg); | |
059ec3d9 PH |
239 | return DEFER; |
240 | } | |
059ec3d9 PH |
241 | } |
242 | ||
243 | ||
244 | ||
c8dfb21d | 245 | #ifdef EXIM_HAVE_EPHEM_RSA_KEX |
059ec3d9 PH |
246 | /************************************************* |
247 | * Callback to generate RSA key * | |
248 | *************************************************/ | |
249 | ||
250 | /* | |
251 | Arguments: | |
252 | s SSL connection | |
253 | export not used | |
254 | keylength keylength | |
255 | ||
256 | Returns: pointer to generated key | |
257 | */ | |
258 | ||
259 | static RSA * | |
260 | rsa_callback(SSL *s, int export, int keylength) | |
261 | { | |
262 | RSA *rsa_key; | |
c8dfb21d JH |
263 | #ifdef EXIM_HAVE_RSA_GENKEY_EX |
264 | BIGNUM *bn = BN_new(); | |
265 | #endif | |
266 | ||
059ec3d9 PH |
267 | export = export; /* Shut picky compilers up */ |
268 | DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength); | |
c8dfb21d JH |
269 | |
270 | #ifdef EXIM_HAVE_RSA_GENKEY_EX | |
271 | if ( !BN_set_word(bn, (unsigned long)RSA_F4) | |
f2cb6292 | 272 | || !(rsa_key = RSA_new()) |
c8dfb21d JH |
273 | || !RSA_generate_key_ex(rsa_key, keylength, bn, NULL) |
274 | ) | |
275 | #else | |
23bb6982 | 276 | if (!(rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL))) |
c8dfb21d JH |
277 | #endif |
278 | ||
059ec3d9 PH |
279 | { |
280 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
281 | log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s", | |
282 | ssl_errstring); | |
283 | return NULL; | |
284 | } | |
285 | return rsa_key; | |
286 | } | |
c8dfb21d | 287 | #endif |
059ec3d9 PH |
288 | |
289 | ||
290 | ||
f5d78688 | 291 | /* Extreme debug |
f2de3a33 | 292 | #ifndef DISABLE_OCSP |
f5d78688 JH |
293 | void |
294 | x509_store_dump_cert_s_names(X509_STORE * store) | |
295 | { | |
296 | STACK_OF(X509_OBJECT) * roots= store->objs; | |
297 | int i; | |
298 | static uschar name[256]; | |
299 | ||
300 | for(i= 0; i<sk_X509_OBJECT_num(roots); i++) | |
301 | { | |
302 | X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i); | |
303 | if(tmp_obj->type == X509_LU_X509) | |
304 | { | |
305 | X509 * current_cert= tmp_obj->data.x509; | |
306 | X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name)); | |
f69979cf | 307 | name[sizeof(name)-1] = '\0'; |
f5d78688 JH |
308 | debug_printf(" %s\n", name); |
309 | } | |
310 | } | |
311 | } | |
312 | #endif | |
313 | */ | |
314 | ||
059ec3d9 | 315 | |
0cbf2b82 | 316 | #ifndef DISABLE_EVENT |
f69979cf JH |
317 | static int |
318 | verify_event(tls_support * tlsp, X509 * cert, int depth, const uschar * dn, | |
319 | BOOL *calledp, const BOOL *optionalp, const uschar * what) | |
320 | { | |
321 | uschar * ev; | |
322 | uschar * yield; | |
323 | X509 * old_cert; | |
324 | ||
325 | ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action; | |
326 | if (ev) | |
327 | { | |
aaba7d03 | 328 | DEBUG(D_tls) debug_printf("verify_event: %s %d\n", what, depth); |
f69979cf JH |
329 | old_cert = tlsp->peercert; |
330 | tlsp->peercert = X509_dup(cert); | |
331 | /* NB we do not bother setting peerdn */ | |
332 | if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth)))) | |
333 | { | |
334 | log_write(0, LOG_MAIN, "[%s] %s verify denied by event-action: " | |
335 | "depth=%d cert=%s: %s", | |
336 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
337 | what, depth, dn, yield); | |
338 | *calledp = TRUE; | |
339 | if (!*optionalp) | |
340 | { | |
341 | if (old_cert) tlsp->peercert = old_cert; /* restore 1st failing cert */ | |
342 | return 1; /* reject (leaving peercert set) */ | |
343 | } | |
344 | DEBUG(D_tls) debug_printf("Event-action verify failure overridden " | |
345 | "(host in tls_try_verify_hosts)\n"); | |
346 | } | |
347 | X509_free(tlsp->peercert); | |
348 | tlsp->peercert = old_cert; | |
349 | } | |
350 | return 0; | |
351 | } | |
352 | #endif | |
353 | ||
059ec3d9 PH |
354 | /************************************************* |
355 | * Callback for verification * | |
356 | *************************************************/ | |
357 | ||
358 | /* The SSL library does certificate verification if set up to do so. This | |
359 | callback has the current yes/no state is in "state". If verification succeeded, | |
f69979cf JH |
360 | we set the certificate-verified flag. If verification failed, what happens |
361 | depends on whether the client is required to present a verifiable certificate | |
362 | or not. | |
059ec3d9 PH |
363 | |
364 | If verification is optional, we change the state to yes, but still log the | |
365 | verification error. For some reason (it really would help to have proper | |
366 | documentation of OpenSSL), this callback function then gets called again, this | |
f69979cf JH |
367 | time with state = 1. We must take care not to set the private verified flag on |
368 | the second time through. | |
059ec3d9 PH |
369 | |
370 | Note: this function is not called if the client fails to present a certificate | |
371 | when asked. We get here only if a certificate has been received. Handling of | |
372 | optional verification for this case is done when requesting SSL to verify, by | |
373 | setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case. | |
374 | ||
a7538db1 JH |
375 | May be called multiple times for different issues with a certificate, even |
376 | for a given "depth" in the certificate chain. | |
377 | ||
059ec3d9 | 378 | Arguments: |
f2f2c91b JH |
379 | preverify_ok current yes/no state as 1/0 |
380 | x509ctx certificate information. | |
381 | tlsp per-direction (client vs. server) support data | |
382 | calledp has-been-called flag | |
383 | optionalp verification-is-optional flag | |
059ec3d9 | 384 | |
f2f2c91b | 385 | Returns: 0 if verification should fail, otherwise 1 |
059ec3d9 PH |
386 | */ |
387 | ||
388 | static int | |
f2f2c91b | 389 | verify_callback(int preverify_ok, X509_STORE_CTX *x509ctx, |
421aff85 | 390 | tls_support *tlsp, BOOL *calledp, BOOL *optionalp) |
059ec3d9 | 391 | { |
421aff85 | 392 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); |
a7538db1 | 393 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
f69979cf | 394 | uschar dn[256]; |
059ec3d9 | 395 | |
f69979cf JH |
396 | X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)); |
397 | dn[sizeof(dn)-1] = '\0'; | |
059ec3d9 | 398 | |
f2f2c91b | 399 | if (preverify_ok == 0) |
059ec3d9 | 400 | { |
4c01d6ab JH |
401 | log_write(0, LOG_MAIN, "[%s] SSL verify error: depth=%d error=%s cert=%s", |
402 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
a7538db1 | 403 | depth, |
421aff85 | 404 | X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), |
f69979cf | 405 | dn); |
a2ff477a | 406 | *calledp = TRUE; |
9d1c15ef JH |
407 | if (!*optionalp) |
408 | { | |
f69979cf JH |
409 | if (!tlsp->peercert) |
410 | tlsp->peercert = X509_dup(cert); /* record failing cert */ | |
411 | return 0; /* reject */ | |
9d1c15ef | 412 | } |
059ec3d9 PH |
413 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
414 | "tls_try_verify_hosts)\n"); | |
059ec3d9 PH |
415 | } |
416 | ||
a7538db1 | 417 | else if (depth != 0) |
059ec3d9 | 418 | { |
f69979cf | 419 | DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, dn); |
f2de3a33 | 420 | #ifndef DISABLE_OCSP |
f5d78688 JH |
421 | if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store) |
422 | { /* client, wanting stapling */ | |
423 | /* Add the server cert's signing chain as the one | |
424 | for the verification of the OCSP stapled information. */ | |
94431adb | 425 | |
f5d78688 | 426 | if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, |
421aff85 | 427 | cert)) |
f5d78688 JH |
428 | ERR_clear_error(); |
429 | } | |
a7538db1 | 430 | #endif |
0cbf2b82 | 431 | #ifndef DISABLE_EVENT |
f69979cf JH |
432 | if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) |
433 | return 0; /* reject, with peercert set */ | |
f5d78688 | 434 | #endif |
059ec3d9 PH |
435 | } |
436 | else | |
437 | { | |
55414b25 | 438 | const uschar * verify_cert_hostnames; |
e51c7be2 | 439 | |
e51c7be2 JH |
440 | if ( tlsp == &tls_out |
441 | && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames))) | |
442 | /* client, wanting hostname check */ | |
e51c7be2 | 443 | { |
f69979cf | 444 | |
740f36d4 | 445 | #ifdef EXIM_HAVE_OPENSSL_CHECKHOST |
f69979cf JH |
446 | # ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
447 | # define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0 | |
448 | # endif | |
449 | # ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS | |
450 | # define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0 | |
451 | # endif | |
e51c7be2 | 452 | int sep = 0; |
55414b25 | 453 | const uschar * list = verify_cert_hostnames; |
e51c7be2 | 454 | uschar * name; |
d8e7834a JH |
455 | int rc; |
456 | while ((name = string_nextinlist(&list, &sep, NULL, 0))) | |
f40d5be3 | 457 | if ((rc = X509_check_host(cert, CCS name, 0, |
8d692470 | 458 | X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
740f36d4 JH |
459 | | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS, |
460 | NULL))) | |
d8e7834a JH |
461 | { |
462 | if (rc < 0) | |
463 | { | |
93a6fce2 | 464 | log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", |
4c01d6ab | 465 | tlsp == &tls_out ? deliver_host_address : sender_host_address); |
d8e7834a JH |
466 | name = NULL; |
467 | } | |
e51c7be2 | 468 | break; |
d8e7834a | 469 | } |
e51c7be2 | 470 | if (!name) |
f69979cf | 471 | #else |
e51c7be2 | 472 | if (!tls_is_name_for_cert(verify_cert_hostnames, cert)) |
f69979cf | 473 | #endif |
e51c7be2 JH |
474 | { |
475 | log_write(0, LOG_MAIN, | |
93a6fce2 | 476 | "[%s] SSL verify error: certificate name mismatch: \"%s\"", |
4c01d6ab | 477 | tlsp == &tls_out ? deliver_host_address : sender_host_address, |
f69979cf | 478 | dn); |
a3ef7310 JH |
479 | *calledp = TRUE; |
480 | if (!*optionalp) | |
f69979cf JH |
481 | { |
482 | if (!tlsp->peercert) | |
483 | tlsp->peercert = X509_dup(cert); /* record failing cert */ | |
484 | return 0; /* reject */ | |
485 | } | |
a3ef7310 JH |
486 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
487 | "tls_try_verify_hosts)\n"); | |
e51c7be2 | 488 | } |
f69979cf | 489 | } |
e51c7be2 | 490 | |
0cbf2b82 | 491 | #ifndef DISABLE_EVENT |
f69979cf JH |
492 | if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) |
493 | return 0; /* reject, with peercert set */ | |
e51c7be2 JH |
494 | #endif |
495 | ||
93dcb1c2 | 496 | DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n", |
f69979cf | 497 | *calledp ? "" : " authenticated", dn); |
93dcb1c2 JH |
498 | if (!*calledp) tlsp->certificate_verified = TRUE; |
499 | *calledp = TRUE; | |
059ec3d9 PH |
500 | } |
501 | ||
a7538db1 | 502 | return 1; /* accept, at least for this level */ |
059ec3d9 PH |
503 | } |
504 | ||
a2ff477a | 505 | static int |
f2f2c91b | 506 | verify_callback_client(int preverify_ok, X509_STORE_CTX *x509ctx) |
a2ff477a | 507 | { |
f2f2c91b JH |
508 | return verify_callback(preverify_ok, x509ctx, &tls_out, |
509 | &client_verify_callback_called, &client_verify_optional); | |
a2ff477a JH |
510 | } |
511 | ||
512 | static int | |
f2f2c91b | 513 | verify_callback_server(int preverify_ok, X509_STORE_CTX *x509ctx) |
a2ff477a | 514 | { |
f2f2c91b JH |
515 | return verify_callback(preverify_ok, x509ctx, &tls_in, |
516 | &server_verify_callback_called, &server_verify_optional); | |
a2ff477a JH |
517 | } |
518 | ||
059ec3d9 | 519 | |
e5cccda9 | 520 | #ifdef EXPERIMENTAL_DANE |
53a7196b | 521 | |
e5cccda9 JH |
522 | /* This gets called *by* the dane library verify callback, which interposes |
523 | itself. | |
524 | */ | |
525 | static int | |
f2f2c91b | 526 | verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx) |
e5cccda9 JH |
527 | { |
528 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); | |
f69979cf | 529 | uschar dn[256]; |
0cbf2b82 | 530 | #ifndef DISABLE_EVENT |
83b27293 | 531 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
f69979cf | 532 | BOOL dummy_called, optional = FALSE; |
83b27293 | 533 | #endif |
e5cccda9 | 534 | |
f69979cf JH |
535 | X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)); |
536 | dn[sizeof(dn)-1] = '\0'; | |
e5cccda9 | 537 | |
f2f2c91b JH |
538 | DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n", |
539 | preverify_ok ? "ok":"BAD", depth, dn); | |
e5cccda9 | 540 | |
0cbf2b82 | 541 | #ifndef DISABLE_EVENT |
f69979cf JH |
542 | if (verify_event(&tls_out, cert, depth, dn, |
543 | &dummy_called, &optional, US"DANE")) | |
544 | return 0; /* reject, with peercert set */ | |
83b27293 JH |
545 | #endif |
546 | ||
f2f2c91b | 547 | if (preverify_ok == 1) |
53a7196b | 548 | tls_out.dane_verified = |
e5cccda9 | 549 | tls_out.certificate_verified = TRUE; |
f2f2c91b JH |
550 | else |
551 | { | |
552 | int err = X509_STORE_CTX_get_error(x509ctx); | |
553 | DEBUG(D_tls) | |
554 | debug_printf(" - err %d '%s'\n", err, X509_verify_cert_error_string(err)); | |
3c51463e | 555 | if (err == X509_V_ERR_APPLICATION_VERIFICATION) |
f2f2c91b JH |
556 | preverify_ok = 1; |
557 | } | |
558 | return preverify_ok; | |
e5cccda9 | 559 | } |
53a7196b JH |
560 | |
561 | #endif /*EXPERIMENTAL_DANE*/ | |
e5cccda9 | 562 | |
059ec3d9 PH |
563 | |
564 | /************************************************* | |
565 | * Information callback * | |
566 | *************************************************/ | |
567 | ||
568 | /* The SSL library functions call this from time to time to indicate what they | |
7be682ca PP |
569 | are doing. We copy the string to the debugging output when TLS debugging has |
570 | been requested. | |
059ec3d9 PH |
571 | |
572 | Arguments: | |
573 | s the SSL connection | |
574 | where | |
575 | ret | |
576 | ||
577 | Returns: nothing | |
578 | */ | |
579 | ||
580 | static void | |
581 | info_callback(SSL *s, int where, int ret) | |
582 | { | |
583 | where = where; | |
584 | ret = ret; | |
585 | DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s)); | |
586 | } | |
587 | ||
588 | ||
589 | ||
590 | /************************************************* | |
591 | * Initialize for DH * | |
592 | *************************************************/ | |
593 | ||
594 | /* If dhparam is set, expand it, and load up the parameters for DH encryption. | |
595 | ||
596 | Arguments: | |
038597d2 | 597 | sctx The current SSL CTX (inbound or outbound) |
a799883d | 598 | dhparam DH parameter file or fixed parameter identity string |
7199e1ee | 599 | host connected host, if client; NULL if server |
059ec3d9 PH |
600 | |
601 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
602 | */ | |
603 | ||
604 | static BOOL | |
b8b1b5cb | 605 | init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host) |
059ec3d9 | 606 | { |
059ec3d9 PH |
607 | BIO *bio; |
608 | DH *dh; | |
609 | uschar *dhexpanded; | |
a799883d | 610 | const char *pem; |
059ec3d9 PH |
611 | |
612 | if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded)) | |
613 | return FALSE; | |
614 | ||
0df4ab80 | 615 | if (!dhexpanded || !*dhexpanded) |
a799883d | 616 | bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1); |
a799883d | 617 | else if (dhexpanded[0] == '/') |
059ec3d9 | 618 | { |
0df4ab80 | 619 | if (!(bio = BIO_new_file(CS dhexpanded, "r"))) |
059ec3d9 | 620 | { |
7199e1ee | 621 | tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), |
a799883d PP |
622 | host, US strerror(errno)); |
623 | return FALSE; | |
059ec3d9 | 624 | } |
a799883d PP |
625 | } |
626 | else | |
627 | { | |
628 | if (Ustrcmp(dhexpanded, "none") == 0) | |
059ec3d9 | 629 | { |
a799883d PP |
630 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); |
631 | return TRUE; | |
059ec3d9 | 632 | } |
a799883d | 633 | |
0df4ab80 | 634 | if (!(pem = std_dh_prime_named(dhexpanded))) |
a799883d PP |
635 | { |
636 | tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded), | |
637 | host, US strerror(errno)); | |
638 | return FALSE; | |
639 | } | |
640 | bio = BIO_new_mem_buf(CS pem, -1); | |
641 | } | |
642 | ||
0df4ab80 | 643 | if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL))) |
a799883d | 644 | { |
059ec3d9 | 645 | BIO_free(bio); |
a799883d PP |
646 | tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded), |
647 | host, NULL); | |
648 | return FALSE; | |
649 | } | |
650 | ||
651 | /* Even if it is larger, we silently return success rather than cause things | |
652 | * to fail out, so that a too-large DH will not knock out all TLS; it's a | |
653 | * debatable choice. */ | |
654 | if ((8*DH_size(dh)) > tls_dh_max_bits) | |
655 | { | |
656 | DEBUG(D_tls) | |
657 | debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d", | |
658 | 8*DH_size(dh), tls_dh_max_bits); | |
659 | } | |
660 | else | |
661 | { | |
662 | SSL_CTX_set_tmp_dh(sctx, dh); | |
663 | DEBUG(D_tls) | |
664 | debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n", | |
665 | dhexpanded ? dhexpanded : US"default", 8*DH_size(dh)); | |
059ec3d9 PH |
666 | } |
667 | ||
a799883d PP |
668 | DH_free(dh); |
669 | BIO_free(bio); | |
670 | ||
671 | return TRUE; | |
059ec3d9 PH |
672 | } |
673 | ||
674 | ||
675 | ||
676 | ||
038597d2 PP |
677 | /************************************************* |
678 | * Initialize for ECDH * | |
679 | *************************************************/ | |
680 | ||
681 | /* Load parameters for ECDH encryption. | |
682 | ||
683 | For now, we stick to NIST P-256 because: it's simple and easy to configure; | |
684 | it avoids any patent issues that might bite redistributors; despite events in | |
685 | the news and concerns over curve choices, we're not cryptographers, we're not | |
686 | pretending to be, and this is "good enough" to be better than no support, | |
687 | protecting against most adversaries. Given another year or two, there might | |
688 | be sufficient clarity about a "right" way forward to let us make an informed | |
689 | decision, instead of a knee-jerk reaction. | |
690 | ||
691 | Longer-term, we should look at supporting both various named curves and | |
692 | external files generated with "openssl ecparam", much as we do for init_dh(). | |
693 | We should also support "none" as a value, to explicitly avoid initialisation. | |
694 | ||
695 | Patches welcome. | |
696 | ||
697 | Arguments: | |
698 | sctx The current SSL CTX (inbound or outbound) | |
699 | host connected host, if client; NULL if server | |
700 | ||
701 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
702 | */ | |
703 | ||
704 | static BOOL | |
10ca4f1c | 705 | init_ecdh(SSL_CTX * sctx, host_item * host) |
038597d2 | 706 | { |
63f0dbe0 JH |
707 | #ifdef OPENSSL_NO_ECDH |
708 | return TRUE; | |
709 | #else | |
710 | ||
10ca4f1c JH |
711 | EC_KEY * ecdh; |
712 | uschar * exp_curve; | |
713 | int nid; | |
714 | BOOL rv; | |
715 | ||
038597d2 PP |
716 | if (host) /* No ECDH setup for clients, only for servers */ |
717 | return TRUE; | |
718 | ||
10ca4f1c | 719 | # ifndef EXIM_HAVE_ECDH |
038597d2 PP |
720 | DEBUG(D_tls) |
721 | debug_printf("No OpenSSL API to define ECDH parameters, skipping\n"); | |
722 | return TRUE; | |
038597d2 | 723 | # else |
10ca4f1c JH |
724 | |
725 | if (!expand_check(tls_eccurve, US"tls_eccurve", &exp_curve)) | |
726 | return FALSE; | |
727 | if (!exp_curve || !*exp_curve) | |
728 | return TRUE; | |
729 | ||
730 | # ifdef EXIM_HAVE_OPENSSL_ECDH_AUTO | |
731 | /* check if new enough library to support auto ECDH temp key parameter selection */ | |
732 | if (Ustrcmp(exp_curve, "auto") == 0) | |
038597d2 | 733 | { |
10ca4f1c JH |
734 | DEBUG(D_tls) debug_printf( |
735 | "ECDH temp key parameter settings: OpenSSL 1.2+ autoselection\n"); | |
736 | SSL_CTX_set_ecdh_auto(sctx, 1); | |
737 | return TRUE; | |
738 | } | |
739 | # endif | |
038597d2 | 740 | |
10ca4f1c JH |
741 | DEBUG(D_tls) debug_printf("ECDH: curve '%s'\n", exp_curve); |
742 | if ( (nid = OBJ_sn2nid (CCS exp_curve)) == NID_undef | |
743 | # ifdef EXIM_HAVE_OPENSSL_EC_NIST2NID | |
744 | && (nid = EC_curve_nist2nid(CCS exp_curve)) == NID_undef | |
745 | # endif | |
746 | ) | |
747 | { | |
748 | tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", | |
749 | exp_curve), | |
750 | host, NULL); | |
751 | return FALSE; | |
752 | } | |
038597d2 | 753 | |
10ca4f1c JH |
754 | if (!(ecdh = EC_KEY_new_by_curve_name(nid))) |
755 | { | |
aa7751be | 756 | tls_error(US"Unable to create ec curve", host, NULL); |
10ca4f1c | 757 | return FALSE; |
038597d2 | 758 | } |
10ca4f1c JH |
759 | |
760 | /* The "tmp" in the name here refers to setting a temporary key | |
761 | not to the stability of the interface. */ | |
762 | ||
763 | if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0)) | |
764 | tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), host, NULL); | |
765 | else | |
766 | DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve); | |
767 | ||
768 | EC_KEY_free(ecdh); | |
769 | return !rv; | |
770 | ||
771 | # endif /*EXIM_HAVE_ECDH*/ | |
772 | #endif /*OPENSSL_NO_ECDH*/ | |
038597d2 PP |
773 | } |
774 | ||
775 | ||
776 | ||
777 | ||
f2de3a33 | 778 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
779 | /************************************************* |
780 | * Load OCSP information into state * | |
781 | *************************************************/ | |
782 | ||
f5d78688 | 783 | /* Called to load the server OCSP response from the given file into memory, once |
3f7eeb86 PP |
784 | caller has determined this is needed. Checks validity. Debugs a message |
785 | if invalid. | |
786 | ||
787 | ASSUMES: single response, for single cert. | |
788 | ||
789 | Arguments: | |
790 | sctx the SSL_CTX* to update | |
791 | cbinfo various parts of session state | |
792 | expanded the filename putatively holding an OCSP response | |
793 | ||
794 | */ | |
795 | ||
796 | static void | |
f5d78688 | 797 | ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded) |
3f7eeb86 PP |
798 | { |
799 | BIO *bio; | |
800 | OCSP_RESPONSE *resp; | |
801 | OCSP_BASICRESP *basic_response; | |
802 | OCSP_SINGLERESP *single_response; | |
803 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
804 | X509_STORE *store; | |
805 | unsigned long verify_flags; | |
806 | int status, reason, i; | |
807 | ||
f5d78688 JH |
808 | cbinfo->u_ocsp.server.file_expanded = string_copy(expanded); |
809 | if (cbinfo->u_ocsp.server.response) | |
3f7eeb86 | 810 | { |
f5d78688 JH |
811 | OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response); |
812 | cbinfo->u_ocsp.server.response = NULL; | |
3f7eeb86 PP |
813 | } |
814 | ||
f5d78688 | 815 | bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb"); |
3f7eeb86 PP |
816 | if (!bio) |
817 | { | |
818 | DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", | |
f5d78688 | 819 | cbinfo->u_ocsp.server.file_expanded); |
3f7eeb86 PP |
820 | return; |
821 | } | |
822 | ||
823 | resp = d2i_OCSP_RESPONSE_bio(bio, NULL); | |
824 | BIO_free(bio); | |
825 | if (!resp) | |
826 | { | |
827 | DEBUG(D_tls) debug_printf("Error reading OCSP response.\n"); | |
828 | return; | |
829 | } | |
830 | ||
831 | status = OCSP_response_status(resp); | |
832 | if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) | |
833 | { | |
834 | DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", | |
835 | OCSP_response_status_str(status), status); | |
f5d78688 | 836 | goto bad; |
3f7eeb86 PP |
837 | } |
838 | ||
839 | basic_response = OCSP_response_get1_basic(resp); | |
840 | if (!basic_response) | |
841 | { | |
842 | DEBUG(D_tls) | |
843 | debug_printf("OCSP response parse error: unable to extract basic response.\n"); | |
f5d78688 | 844 | goto bad; |
3f7eeb86 PP |
845 | } |
846 | ||
847 | store = SSL_CTX_get_cert_store(sctx); | |
848 | verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ | |
849 | ||
850 | /* May need to expose ability to adjust those flags? | |
851 | OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT | |
852 | OCSP_TRUSTOTHER OCSP_NOINTERN */ | |
853 | ||
854 | i = OCSP_basic_verify(basic_response, NULL, store, verify_flags); | |
855 | if (i <= 0) | |
856 | { | |
857 | DEBUG(D_tls) { | |
858 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
859 | debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); | |
f5d78688 JH |
860 | } |
861 | goto bad; | |
3f7eeb86 PP |
862 | } |
863 | ||
864 | /* Here's the simplifying assumption: there's only one response, for the | |
865 | one certificate we use, and nothing for anything else in a chain. If this | |
866 | proves false, we need to extract a cert id from our issued cert | |
867 | (tls_certificate) and use that for OCSP_resp_find_status() (which finds the | |
868 | right cert in the stack and then calls OCSP_single_get0_status()). | |
869 | ||
870 | I'm hoping to avoid reworking a bunch more of how we handle state here. */ | |
871 | single_response = OCSP_resp_get0(basic_response, 0); | |
872 | if (!single_response) | |
873 | { | |
874 | DEBUG(D_tls) | |
875 | debug_printf("Unable to get first response from OCSP basic response.\n"); | |
f5d78688 | 876 | goto bad; |
3f7eeb86 PP |
877 | } |
878 | ||
879 | status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd); | |
f5d78688 | 880 | if (status != V_OCSP_CERTSTATUS_GOOD) |
3f7eeb86 | 881 | { |
f5d78688 JH |
882 | DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n", |
883 | OCSP_cert_status_str(status), status, | |
884 | OCSP_crl_reason_str(reason), reason); | |
885 | goto bad; | |
3f7eeb86 PP |
886 | } |
887 | ||
888 | if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
889 | { | |
890 | DEBUG(D_tls) debug_printf("OCSP status invalid times.\n"); | |
f5d78688 | 891 | goto bad; |
3f7eeb86 PP |
892 | } |
893 | ||
f5d78688 | 894 | supply_response: |
018058b2 | 895 | cbinfo->u_ocsp.server.response = resp; |
f5d78688 JH |
896 | return; |
897 | ||
898 | bad: | |
018058b2 JH |
899 | if (running_in_test_harness) |
900 | { | |
901 | extern char ** environ; | |
902 | uschar ** p; | |
bc3c7bb7 | 903 | if (environ) for (p = USS environ; *p != NULL; p++) |
018058b2 JH |
904 | if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) |
905 | { | |
906 | DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n"); | |
907 | goto supply_response; | |
908 | } | |
909 | } | |
f5d78688 | 910 | return; |
3f7eeb86 | 911 | } |
f2de3a33 | 912 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
913 | |
914 | ||
915 | ||
916 | ||
23bb6982 JH |
917 | /* Create and install a selfsigned certificate, for use in server mode */ |
918 | ||
919 | static int | |
920 | tls_install_selfsign(SSL_CTX * sctx) | |
921 | { | |
922 | X509 * x509 = NULL; | |
923 | EVP_PKEY * pkey; | |
924 | RSA * rsa; | |
925 | X509_NAME * name; | |
926 | uschar * where; | |
927 | ||
928 | where = US"allocating pkey"; | |
929 | if (!(pkey = EVP_PKEY_new())) | |
930 | goto err; | |
931 | ||
932 | where = US"allocating cert"; | |
933 | if (!(x509 = X509_new())) | |
934 | goto err; | |
935 | ||
936 | where = US"generating pkey"; | |
937 | /* deprecated, use RSA_generate_key_ex() */ | |
938 | if (!(rsa = RSA_generate_key(1024, RSA_F4, NULL, NULL))) | |
939 | goto err; | |
940 | ||
941 | where = US"assiging pkey"; | |
942 | if (!EVP_PKEY_assign_RSA(pkey, rsa)) | |
943 | goto err; | |
944 | ||
945 | X509_set_version(x509, 2); /* N+1 - version 3 */ | |
946 | ASN1_INTEGER_set(X509_get_serialNumber(x509), 0); | |
947 | X509_gmtime_adj(X509_get_notBefore(x509), 0); | |
948 | X509_gmtime_adj(X509_get_notAfter(x509), (long)60 * 60); /* 1 hour */ | |
949 | X509_set_pubkey(x509, pkey); | |
950 | ||
951 | name = X509_get_subject_name(x509); | |
952 | X509_NAME_add_entry_by_txt(name, "C", | |
953 | MBSTRING_ASC, "UK", -1, -1, 0); | |
954 | X509_NAME_add_entry_by_txt(name, "O", | |
955 | MBSTRING_ASC, "Exim Developers", -1, -1, 0); | |
956 | X509_NAME_add_entry_by_txt(name, "CN", | |
957 | MBSTRING_ASC, CS smtp_active_hostname, -1, -1, 0); | |
958 | X509_set_issuer_name(x509, name); | |
959 | ||
960 | where = US"signing cert"; | |
961 | if (!X509_sign(x509, pkey, EVP_md5())) | |
962 | goto err; | |
963 | ||
964 | where = US"installing selfsign cert"; | |
965 | if (!SSL_CTX_use_certificate(sctx, x509)) | |
966 | goto err; | |
967 | ||
968 | where = US"installing selfsign key"; | |
969 | if (!SSL_CTX_use_PrivateKey(sctx, pkey)) | |
970 | goto err; | |
971 | ||
972 | return OK; | |
973 | ||
974 | err: | |
975 | (void) tls_error(where, NULL, NULL); | |
976 | if (x509) X509_free(x509); | |
977 | if (pkey) EVP_PKEY_free(pkey); | |
978 | return DEFER; | |
979 | } | |
980 | ||
981 | ||
982 | ||
983 | ||
7be682ca PP |
984 | /************************************************* |
985 | * Expand key and cert file specs * | |
986 | *************************************************/ | |
987 | ||
f5d78688 | 988 | /* Called once during tls_init and possibly again during TLS setup, for a |
7be682ca PP |
989 | new context, if Server Name Indication was used and tls_sni was seen in |
990 | the certificate string. | |
991 | ||
992 | Arguments: | |
993 | sctx the SSL_CTX* to update | |
994 | cbinfo various parts of session state | |
995 | ||
996 | Returns: OK/DEFER/FAIL | |
997 | */ | |
998 | ||
999 | static int | |
3f7eeb86 | 1000 | tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo) |
7be682ca PP |
1001 | { |
1002 | uschar *expanded; | |
1003 | ||
23bb6982 | 1004 | if (!cbinfo->certificate) |
7be682ca | 1005 | { |
23bb6982 JH |
1006 | if (cbinfo->host) /* client */ |
1007 | return OK; | |
1008 | /* server */ | |
1009 | if (tls_install_selfsign(sctx) != OK) | |
1010 | return DEFER; | |
7be682ca | 1011 | } |
23bb6982 JH |
1012 | else |
1013 | { | |
1014 | if (Ustrstr(cbinfo->certificate, US"tls_sni") || | |
1015 | Ustrstr(cbinfo->certificate, US"tls_in_sni") || | |
1016 | Ustrstr(cbinfo->certificate, US"tls_out_sni") | |
1017 | ) | |
1018 | reexpand_tls_files_for_sni = TRUE; | |
7be682ca | 1019 | |
23bb6982 JH |
1020 | if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded)) |
1021 | return DEFER; | |
1022 | ||
1023 | if (expanded != NULL) | |
1024 | { | |
1025 | DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); | |
1026 | if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded)) | |
1027 | return tls_error(string_sprintf( | |
1028 | "SSL_CTX_use_certificate_chain_file file=%s", expanded), | |
1029 | cbinfo->host, NULL); | |
1030 | } | |
7be682ca | 1031 | |
23bb6982 JH |
1032 | if (cbinfo->privatekey != NULL && |
1033 | !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded)) | |
1034 | return DEFER; | |
7be682ca | 1035 | |
23bb6982 JH |
1036 | /* If expansion was forced to fail, key_expanded will be NULL. If the result |
1037 | of the expansion is an empty string, ignore it also, and assume the private | |
1038 | key is in the same file as the certificate. */ | |
1039 | ||
1040 | if (expanded && *expanded) | |
1041 | { | |
1042 | DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); | |
1043 | if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM)) | |
1044 | return tls_error(string_sprintf( | |
1045 | "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL); | |
1046 | } | |
7be682ca PP |
1047 | } |
1048 | ||
f2de3a33 | 1049 | #ifndef DISABLE_OCSP |
f40d5be3 | 1050 | if (cbinfo->is_server && cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1051 | { |
f5d78688 | 1052 | if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded)) |
3f7eeb86 PP |
1053 | return DEFER; |
1054 | ||
f40d5be3 | 1055 | if (expanded && *expanded) |
3f7eeb86 PP |
1056 | { |
1057 | DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded); | |
f40d5be3 JH |
1058 | if ( cbinfo->u_ocsp.server.file_expanded |
1059 | && (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0)) | |
3f7eeb86 | 1060 | { |
f40d5be3 JH |
1061 | DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n"); |
1062 | } | |
1063 | else | |
1064 | { | |
1065 | ocsp_load_response(sctx, cbinfo, expanded); | |
3f7eeb86 PP |
1066 | } |
1067 | } | |
1068 | } | |
1069 | #endif | |
1070 | ||
7be682ca PP |
1071 | return OK; |
1072 | } | |
1073 | ||
1074 | ||
1075 | ||
1076 | ||
1077 | /************************************************* | |
1078 | * Callback to handle SNI * | |
1079 | *************************************************/ | |
1080 | ||
1081 | /* Called when acting as server during the TLS session setup if a Server Name | |
1082 | Indication extension was sent by the client. | |
1083 | ||
1084 | API documentation is OpenSSL s_server.c implementation. | |
1085 | ||
1086 | Arguments: | |
1087 | s SSL* of the current session | |
1088 | ad unknown (part of OpenSSL API) (unused) | |
1089 | arg Callback of "our" registered data | |
1090 | ||
1091 | Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK} | |
1092 | */ | |
1093 | ||
3bcbbbe2 | 1094 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
7be682ca PP |
1095 | static int |
1096 | tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg) | |
1097 | { | |
1098 | const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); | |
3f7eeb86 | 1099 | tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; |
7be682ca | 1100 | int rc; |
3f0945ff | 1101 | int old_pool = store_pool; |
7be682ca PP |
1102 | |
1103 | if (!servername) | |
1104 | return SSL_TLSEXT_ERR_OK; | |
1105 | ||
3f0945ff | 1106 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername, |
7be682ca PP |
1107 | reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)"); |
1108 | ||
1109 | /* Make the extension value available for expansion */ | |
3f0945ff | 1110 | store_pool = POOL_PERM; |
817d9f57 | 1111 | tls_in.sni = string_copy(US servername); |
3f0945ff | 1112 | store_pool = old_pool; |
7be682ca PP |
1113 | |
1114 | if (!reexpand_tls_files_for_sni) | |
1115 | return SSL_TLSEXT_ERR_OK; | |
1116 | ||
1117 | /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually; | |
1118 | not confident that memcpy wouldn't break some internal reference counting. | |
1119 | Especially since there's a references struct member, which would be off. */ | |
1120 | ||
0df4ab80 | 1121 | if (!(server_sni = SSL_CTX_new(SSLv23_server_method()))) |
7be682ca PP |
1122 | { |
1123 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
1124 | DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring); | |
1125 | return SSL_TLSEXT_ERR_NOACK; | |
1126 | } | |
1127 | ||
1128 | /* Not sure how many of these are actually needed, since SSL object | |
1129 | already exists. Might even need this selfsame callback, for reneg? */ | |
1130 | ||
817d9f57 JH |
1131 | SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx)); |
1132 | SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx)); | |
1133 | SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); | |
1134 | SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); | |
1135 | SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); | |
1136 | SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); | |
038597d2 PP |
1137 | |
1138 | if ( !init_dh(server_sni, cbinfo->dhparam, NULL) | |
1139 | || !init_ecdh(server_sni, NULL) | |
1140 | ) | |
1141 | return SSL_TLSEXT_ERR_NOACK; | |
1142 | ||
7be682ca | 1143 | if (cbinfo->server_cipher_list) |
817d9f57 | 1144 | SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list); |
f2de3a33 | 1145 | #ifndef DISABLE_OCSP |
f5d78688 | 1146 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1147 | { |
f5d78688 | 1148 | SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb); |
14c7b357 | 1149 | SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo); |
3f7eeb86 PP |
1150 | } |
1151 | #endif | |
7be682ca | 1152 | |
983207c1 | 1153 | rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server); |
7be682ca PP |
1154 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
1155 | ||
3f7eeb86 PP |
1156 | /* do this after setup_certs, because this can require the certs for verifying |
1157 | OCSP information. */ | |
038597d2 | 1158 | if ((rc = tls_expand_session_files(server_sni, cbinfo)) != OK) |
0df4ab80 | 1159 | return SSL_TLSEXT_ERR_NOACK; |
a799883d | 1160 | |
7be682ca | 1161 | DEBUG(D_tls) debug_printf("Switching SSL context.\n"); |
817d9f57 | 1162 | SSL_set_SSL_CTX(s, server_sni); |
7be682ca PP |
1163 | |
1164 | return SSL_TLSEXT_ERR_OK; | |
1165 | } | |
3bcbbbe2 | 1166 | #endif /* EXIM_HAVE_OPENSSL_TLSEXT */ |
7be682ca PP |
1167 | |
1168 | ||
1169 | ||
1170 | ||
f2de3a33 | 1171 | #ifndef DISABLE_OCSP |
f5d78688 | 1172 | |
3f7eeb86 PP |
1173 | /************************************************* |
1174 | * Callback to handle OCSP Stapling * | |
1175 | *************************************************/ | |
1176 | ||
1177 | /* Called when acting as server during the TLS session setup if the client | |
1178 | requests OCSP information with a Certificate Status Request. | |
1179 | ||
1180 | Documentation via openssl s_server.c and the Apache patch from the OpenSSL | |
1181 | project. | |
1182 | ||
1183 | */ | |
1184 | ||
1185 | static int | |
f5d78688 | 1186 | tls_server_stapling_cb(SSL *s, void *arg) |
3f7eeb86 PP |
1187 | { |
1188 | const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; | |
1189 | uschar *response_der; | |
1190 | int response_der_len; | |
1191 | ||
af4a1bca | 1192 | DEBUG(D_tls) |
b3ef41c9 | 1193 | debug_printf("Received TLS status request (OCSP stapling); %s response\n", |
f5d78688 JH |
1194 | cbinfo->u_ocsp.server.response ? "have" : "lack"); |
1195 | ||
44662487 | 1196 | tls_in.ocsp = OCSP_NOT_RESP; |
f5d78688 | 1197 | if (!cbinfo->u_ocsp.server.response) |
3f7eeb86 PP |
1198 | return SSL_TLSEXT_ERR_NOACK; |
1199 | ||
1200 | response_der = NULL; | |
44662487 JH |
1201 | response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response, |
1202 | &response_der); | |
3f7eeb86 PP |
1203 | if (response_der_len <= 0) |
1204 | return SSL_TLSEXT_ERR_NOACK; | |
1205 | ||
5e55c7a9 | 1206 | SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len); |
44662487 | 1207 | tls_in.ocsp = OCSP_VFIED; |
3f7eeb86 PP |
1208 | return SSL_TLSEXT_ERR_OK; |
1209 | } | |
1210 | ||
3f7eeb86 | 1211 | |
f5d78688 JH |
1212 | static void |
1213 | time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time) | |
1214 | { | |
1215 | BIO_printf(bp, "\t%s: ", str); | |
1216 | ASN1_GENERALIZEDTIME_print(bp, time); | |
1217 | BIO_puts(bp, "\n"); | |
1218 | } | |
1219 | ||
1220 | static int | |
1221 | tls_client_stapling_cb(SSL *s, void *arg) | |
1222 | { | |
1223 | tls_ext_ctx_cb * cbinfo = arg; | |
1224 | const unsigned char * p; | |
1225 | int len; | |
1226 | OCSP_RESPONSE * rsp; | |
1227 | OCSP_BASICRESP * bs; | |
1228 | int i; | |
1229 | ||
1230 | DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):"); | |
1231 | len = SSL_get_tlsext_status_ocsp_resp(s, &p); | |
1232 | if(!p) | |
1233 | { | |
44662487 | 1234 | /* Expect this when we requested ocsp but got none */ |
6c6d6e48 | 1235 | if (cbinfo->u_ocsp.client.verify_required && LOGGING(tls_cipher)) |
44662487 | 1236 | log_write(0, LOG_MAIN, "Received TLS status callback, null content"); |
f5d78688 JH |
1237 | else |
1238 | DEBUG(D_tls) debug_printf(" null\n"); | |
44662487 | 1239 | return cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 1240 | } |
018058b2 | 1241 | |
f5d78688 JH |
1242 | if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) |
1243 | { | |
018058b2 | 1244 | tls_out.ocsp = OCSP_FAILED; |
6c6d6e48 | 1245 | if (LOGGING(tls_cipher)) |
1eca31ca | 1246 | log_write(0, LOG_MAIN, "Received TLS cert status response, parse error"); |
f5d78688 JH |
1247 | else |
1248 | DEBUG(D_tls) debug_printf(" parse error\n"); | |
1249 | return 0; | |
1250 | } | |
1251 | ||
1252 | if(!(bs = OCSP_response_get1_basic(rsp))) | |
1253 | { | |
018058b2 | 1254 | tls_out.ocsp = OCSP_FAILED; |
6c6d6e48 | 1255 | if (LOGGING(tls_cipher)) |
1eca31ca | 1256 | log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response"); |
f5d78688 JH |
1257 | else |
1258 | DEBUG(D_tls) debug_printf(" error parsing response\n"); | |
1259 | OCSP_RESPONSE_free(rsp); | |
1260 | return 0; | |
1261 | } | |
1262 | ||
1263 | /* We'd check the nonce here if we'd put one in the request. */ | |
1264 | /* However that would defeat cacheability on the server so we don't. */ | |
1265 | ||
f5d78688 JH |
1266 | /* This section of code reworked from OpenSSL apps source; |
1267 | The OpenSSL Project retains copyright: | |
1268 | Copyright (c) 1999 The OpenSSL Project. All rights reserved. | |
1269 | */ | |
1270 | { | |
1271 | BIO * bp = NULL; | |
f5d78688 JH |
1272 | int status, reason; |
1273 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
1274 | ||
1275 | DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE); | |
1276 | ||
1277 | /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */ | |
1278 | ||
1279 | /* Use the chain that verified the server cert to verify the stapled info */ | |
1280 | /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */ | |
1281 | ||
44662487 JH |
1282 | if ((i = OCSP_basic_verify(bs, NULL, |
1283 | cbinfo->u_ocsp.client.verify_store, 0)) <= 0) | |
f5d78688 | 1284 | { |
018058b2 | 1285 | tls_out.ocsp = OCSP_FAILED; |
6c6d6e48 | 1286 | if (LOGGING(tls_cipher)) |
1eca31ca | 1287 | log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable"); |
f5d78688 JH |
1288 | BIO_printf(bp, "OCSP response verify failure\n"); |
1289 | ERR_print_errors(bp); | |
c8dfb21d | 1290 | goto failed; |
f5d78688 JH |
1291 | } |
1292 | ||
1293 | BIO_printf(bp, "OCSP response well-formed and signed OK\n"); | |
1294 | ||
c8dfb21d JH |
1295 | /*XXX So we have a good stapled OCSP status. How do we know |
1296 | it is for the cert of interest? OpenSSL 1.1.0 has a routine | |
1297 | OCSP_resp_find_status() which matches on a cert id, which presumably | |
1298 | we should use. Making an id needs OCSP_cert_id_new(), which takes | |
1299 | issuerName, issuerKey, serialNumber. Are they all in the cert? | |
1300 | ||
1301 | For now, carry on blindly accepting the resp. */ | |
1302 | ||
f5d78688 | 1303 | { |
f5d78688 JH |
1304 | OCSP_SINGLERESP * single; |
1305 | ||
c8dfb21d JH |
1306 | #ifdef EXIM_HAVE_OCSP_RESP_COUNT |
1307 | if (OCSP_resp_count(bs) != 1) | |
1308 | #else | |
1309 | STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; | |
f5d78688 | 1310 | if (sk_OCSP_SINGLERESP_num(sresp) != 1) |
c8dfb21d | 1311 | #endif |
f5d78688 | 1312 | { |
018058b2 | 1313 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1314 | log_write(0, LOG_MAIN, "OCSP stapling " |
1315 | "with multiple responses not handled"); | |
c8dfb21d | 1316 | goto failed; |
f5d78688 JH |
1317 | } |
1318 | single = OCSP_resp_get0(bs, 0); | |
44662487 JH |
1319 | status = OCSP_single_get0_status(single, &reason, &rev, |
1320 | &thisupd, &nextupd); | |
f5d78688 JH |
1321 | } |
1322 | ||
f5d78688 JH |
1323 | DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd); |
1324 | DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd); | |
44662487 JH |
1325 | if (!OCSP_check_validity(thisupd, nextupd, |
1326 | EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
f5d78688 | 1327 | { |
018058b2 | 1328 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
1329 | DEBUG(D_tls) ERR_print_errors(bp); |
1330 | log_write(0, LOG_MAIN, "Server OSCP dates invalid"); | |
f5d78688 | 1331 | } |
44662487 | 1332 | else |
f5d78688 | 1333 | { |
44662487 JH |
1334 | DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n", |
1335 | OCSP_cert_status_str(status)); | |
1336 | switch(status) | |
1337 | { | |
1338 | case V_OCSP_CERTSTATUS_GOOD: | |
44662487 | 1339 | tls_out.ocsp = OCSP_VFIED; |
018058b2 | 1340 | i = 1; |
c8dfb21d | 1341 | goto good; |
44662487 | 1342 | case V_OCSP_CERTSTATUS_REVOKED: |
018058b2 | 1343 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1344 | log_write(0, LOG_MAIN, "Server certificate revoked%s%s", |
1345 | reason != -1 ? "; reason: " : "", | |
1346 | reason != -1 ? OCSP_crl_reason_str(reason) : ""); | |
1347 | DEBUG(D_tls) time_print(bp, "Revocation Time", rev); | |
44662487 JH |
1348 | break; |
1349 | default: | |
018058b2 | 1350 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1351 | log_write(0, LOG_MAIN, |
1352 | "Server certificate status unknown, in OCSP stapling"); | |
44662487 JH |
1353 | break; |
1354 | } | |
f5d78688 | 1355 | } |
c8dfb21d JH |
1356 | failed: |
1357 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1358 | good: | |
f5d78688 JH |
1359 | BIO_free(bp); |
1360 | } | |
1361 | ||
1362 | OCSP_RESPONSE_free(rsp); | |
1363 | return i; | |
1364 | } | |
f2de3a33 | 1365 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
1366 | |
1367 | ||
059ec3d9 PH |
1368 | /************************************************* |
1369 | * Initialize for TLS * | |
1370 | *************************************************/ | |
1371 | ||
e51c7be2 JH |
1372 | /* Called from both server and client code, to do preliminary initialization |
1373 | of the library. We allocate and return a context structure. | |
059ec3d9 PH |
1374 | |
1375 | Arguments: | |
946ecbe0 | 1376 | ctxp returned SSL context |
059ec3d9 PH |
1377 | host connected host, if client; NULL if server |
1378 | dhparam DH parameter file | |
1379 | certificate certificate file | |
1380 | privatekey private key | |
f5d78688 | 1381 | ocsp_file file of stapling info (server); flag for require ocsp (client) |
059ec3d9 | 1382 | addr address if client; NULL if server (for some randomness) |
946ecbe0 | 1383 | cbp place to put allocated callback context |
059ec3d9 PH |
1384 | |
1385 | Returns: OK/DEFER/FAIL | |
1386 | */ | |
1387 | ||
1388 | static int | |
817d9f57 | 1389 | tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate, |
3f7eeb86 | 1390 | uschar *privatekey, |
f2de3a33 | 1391 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1392 | uschar *ocsp_file, |
1393 | #endif | |
817d9f57 | 1394 | address_item *addr, tls_ext_ctx_cb ** cbp) |
059ec3d9 | 1395 | { |
77bb000f | 1396 | long init_options; |
7be682ca | 1397 | int rc; |
77bb000f | 1398 | BOOL okay; |
a7538db1 | 1399 | tls_ext_ctx_cb * cbinfo; |
7be682ca PP |
1400 | |
1401 | cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); | |
1402 | cbinfo->certificate = certificate; | |
1403 | cbinfo->privatekey = privatekey; | |
f2de3a33 | 1404 | #ifndef DISABLE_OCSP |
f5d78688 JH |
1405 | if ((cbinfo->is_server = host==NULL)) |
1406 | { | |
1407 | cbinfo->u_ocsp.server.file = ocsp_file; | |
1408 | cbinfo->u_ocsp.server.file_expanded = NULL; | |
1409 | cbinfo->u_ocsp.server.response = NULL; | |
1410 | } | |
1411 | else | |
1412 | cbinfo->u_ocsp.client.verify_store = NULL; | |
3f7eeb86 | 1413 | #endif |
7be682ca | 1414 | cbinfo->dhparam = dhparam; |
0df4ab80 | 1415 | cbinfo->server_cipher_list = NULL; |
7be682ca | 1416 | cbinfo->host = host; |
0cbf2b82 | 1417 | #ifndef DISABLE_EVENT |
a7538db1 JH |
1418 | cbinfo->event_action = NULL; |
1419 | #endif | |
77bb000f | 1420 | |
059ec3d9 PH |
1421 | SSL_load_error_strings(); /* basic set up */ |
1422 | OpenSSL_add_ssl_algorithms(); | |
1423 | ||
c8dfb21d | 1424 | #ifdef EXIM_HAVE_SHA256 |
77bb000f | 1425 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the |
a0475b69 TK |
1426 | list of available digests. */ |
1427 | EVP_add_digest(EVP_sha256()); | |
cf1ef1a9 | 1428 | #endif |
a0475b69 | 1429 | |
f0f5a555 PP |
1430 | /* Create a context. |
1431 | The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant | |
1432 | negotiation in the different methods; as far as I can tell, the only | |
1433 | *_{server,client}_method which allows negotiation is SSLv23, which exists even | |
1434 | when OpenSSL is built without SSLv2 support. | |
1435 | By disabling with openssl_options, we can let admins re-enable with the | |
1436 | existing knob. */ | |
059ec3d9 | 1437 | |
c8dfb21d | 1438 | *ctxp = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method()); |
059ec3d9 | 1439 | |
c8dfb21d | 1440 | if (!*ctxp) return tls_error(US"SSL_CTX_new", host, NULL); |
059ec3d9 PH |
1441 | |
1442 | /* It turns out that we need to seed the random number generator this early in | |
1443 | order to get the full complement of ciphers to work. It took me roughly a day | |
1444 | of work to discover this by experiment. | |
1445 | ||
1446 | On systems that have /dev/urandom, SSL may automatically seed itself from | |
1447 | there. Otherwise, we have to make something up as best we can. Double check | |
1448 | afterwards. */ | |
1449 | ||
1450 | if (!RAND_status()) | |
1451 | { | |
1452 | randstuff r; | |
9e3331ea | 1453 | gettimeofday(&r.tv, NULL); |
059ec3d9 PH |
1454 | r.p = getpid(); |
1455 | ||
1456 | RAND_seed((uschar *)(&r), sizeof(r)); | |
1457 | RAND_seed((uschar *)big_buffer, big_buffer_size); | |
1458 | if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr)); | |
1459 | ||
1460 | if (!RAND_status()) | |
7199e1ee | 1461 | return tls_error(US"RAND_status", host, |
5ca6d115 | 1462 | US"unable to seed random number generator"); |
059ec3d9 PH |
1463 | } |
1464 | ||
1465 | /* Set up the information callback, which outputs if debugging is at a suitable | |
1466 | level. */ | |
1467 | ||
f69979cf | 1468 | DEBUG(D_tls) SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback); |
059ec3d9 | 1469 | |
c80c5570 | 1470 | /* Automatically re-try reads/writes after renegotiation. */ |
817d9f57 | 1471 | (void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY); |
c80c5570 | 1472 | |
77bb000f PP |
1473 | /* Apply administrator-supplied work-arounds. |
1474 | Historically we applied just one requested option, | |
1475 | SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we | |
1476 | moved to an administrator-controlled list of options to specify and | |
1477 | grandfathered in the first one as the default value for "openssl_options". | |
059ec3d9 | 1478 | |
77bb000f PP |
1479 | No OpenSSL version number checks: the options we accept depend upon the |
1480 | availability of the option value macros from OpenSSL. */ | |
059ec3d9 | 1481 | |
77bb000f PP |
1482 | okay = tls_openssl_options_parse(openssl_options, &init_options); |
1483 | if (!okay) | |
73a46702 | 1484 | return tls_error(US"openssl_options parsing failed", host, NULL); |
77bb000f PP |
1485 | |
1486 | if (init_options) | |
1487 | { | |
1488 | DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); | |
817d9f57 | 1489 | if (!(SSL_CTX_set_options(*ctxp, init_options))) |
77bb000f PP |
1490 | return tls_error(string_sprintf( |
1491 | "SSL_CTX_set_option(%#lx)", init_options), host, NULL); | |
1492 | } | |
1493 | else | |
1494 | DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); | |
059ec3d9 PH |
1495 | |
1496 | /* Initialize with DH parameters if supplied */ | |
10ca4f1c | 1497 | /* Initialize ECDH temp key parameter selection */ |
059ec3d9 | 1498 | |
038597d2 PP |
1499 | if ( !init_dh(*ctxp, dhparam, host) |
1500 | || !init_ecdh(*ctxp, host) | |
1501 | ) | |
1502 | return DEFER; | |
059ec3d9 | 1503 | |
3f7eeb86 | 1504 | /* Set up certificate and key (and perhaps OCSP info) */ |
059ec3d9 | 1505 | |
23bb6982 JH |
1506 | if ((rc = tls_expand_session_files(*ctxp, cbinfo)) != OK) |
1507 | return rc; | |
c91535f3 | 1508 | |
7be682ca | 1509 | /* If we need to handle SNI, do so */ |
3bcbbbe2 | 1510 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
f5d78688 | 1511 | if (host == NULL) /* server */ |
3f0945ff | 1512 | { |
f2de3a33 | 1513 | # ifndef DISABLE_OCSP |
f5d78688 | 1514 | /* We check u_ocsp.server.file, not server.response, because we care about if |
3f7eeb86 PP |
1515 | the option exists, not what the current expansion might be, as SNI might |
1516 | change the certificate and OCSP file in use between now and the time the | |
1517 | callback is invoked. */ | |
f5d78688 | 1518 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1519 | { |
f5d78688 | 1520 | SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb); |
5e55c7a9 | 1521 | SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo); |
3f7eeb86 | 1522 | } |
f5d78688 | 1523 | # endif |
3f0945ff PP |
1524 | /* We always do this, so that $tls_sni is available even if not used in |
1525 | tls_certificate */ | |
817d9f57 JH |
1526 | SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb); |
1527 | SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo); | |
3f0945ff | 1528 | } |
f2de3a33 | 1529 | # ifndef DISABLE_OCSP |
f5d78688 JH |
1530 | else /* client */ |
1531 | if(ocsp_file) /* wanting stapling */ | |
1532 | { | |
1533 | if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new())) | |
1534 | { | |
1535 | DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n"); | |
1536 | return FAIL; | |
1537 | } | |
1538 | SSL_CTX_set_tlsext_status_cb(*ctxp, tls_client_stapling_cb); | |
1539 | SSL_CTX_set_tlsext_status_arg(*ctxp, cbinfo); | |
1540 | } | |
1541 | # endif | |
7be682ca | 1542 | #endif |
059ec3d9 | 1543 | |
e51c7be2 | 1544 | cbinfo->verify_cert_hostnames = NULL; |
e51c7be2 | 1545 | |
c8dfb21d | 1546 | #ifdef EXIM_HAVE_EPHEM_RSA_KEX |
059ec3d9 | 1547 | /* Set up the RSA callback */ |
817d9f57 | 1548 | SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback); |
c8dfb21d | 1549 | #endif |
059ec3d9 PH |
1550 | |
1551 | /* Finally, set the timeout, and we are done */ | |
1552 | ||
817d9f57 | 1553 | SSL_CTX_set_timeout(*ctxp, ssl_session_timeout); |
059ec3d9 | 1554 | DEBUG(D_tls) debug_printf("Initialized TLS\n"); |
7be682ca | 1555 | |
817d9f57 | 1556 | *cbp = cbinfo; |
7be682ca | 1557 | |
059ec3d9 PH |
1558 | return OK; |
1559 | } | |
1560 | ||
1561 | ||
1562 | ||
1563 | ||
1564 | /************************************************* | |
1565 | * Get name of cipher in use * | |
1566 | *************************************************/ | |
1567 | ||
817d9f57 | 1568 | /* |
059ec3d9 | 1569 | Argument: pointer to an SSL structure for the connection |
817d9f57 JH |
1570 | buffer to use for answer |
1571 | size of buffer | |
1572 | pointer to number of bits for cipher | |
059ec3d9 PH |
1573 | Returns: nothing |
1574 | */ | |
1575 | ||
1576 | static void | |
817d9f57 | 1577 | construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits) |
059ec3d9 | 1578 | { |
57b3a7f5 PP |
1579 | /* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't |
1580 | yet reflect that. It should be a safe change anyway, even 0.9.8 versions have | |
1581 | the accessor functions use const in the prototype. */ | |
1582 | const SSL_CIPHER *c; | |
d9784128 | 1583 | const uschar *ver; |
059ec3d9 | 1584 | |
d9784128 | 1585 | ver = (const uschar *)SSL_get_version(ssl); |
059ec3d9 | 1586 | |
57b3a7f5 | 1587 | c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); |
817d9f57 | 1588 | SSL_CIPHER_get_bits(c, bits); |
059ec3d9 | 1589 | |
817d9f57 JH |
1590 | string_format(cipherbuf, bsize, "%s:%s:%u", ver, |
1591 | SSL_CIPHER_get_name(c), *bits); | |
059ec3d9 PH |
1592 | |
1593 | DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf); | |
1594 | } | |
1595 | ||
1596 | ||
f69979cf JH |
1597 | static void |
1598 | peer_cert(SSL * ssl, tls_support * tlsp, uschar * peerdn, unsigned bsize) | |
1599 | { | |
1600 | /*XXX we might consider a list-of-certs variable for the cert chain. | |
1601 | SSL_get_peer_cert_chain(SSL*). We'd need a new variable type and support | |
1602 | in list-handling functions, also consider the difference between the entire | |
1603 | chain and the elements sent by the peer. */ | |
1604 | ||
1605 | /* Will have already noted peercert on a verify fail; possibly not the leaf */ | |
1606 | if (!tlsp->peercert) | |
1607 | tlsp->peercert = SSL_get_peer_certificate(ssl); | |
1608 | /* Beware anonymous ciphers which lead to server_cert being NULL */ | |
1609 | if (tlsp->peercert) | |
1610 | { | |
1611 | X509_NAME_oneline(X509_get_subject_name(tlsp->peercert), CS peerdn, bsize); | |
1612 | peerdn[bsize-1] = '\0'; | |
1613 | tlsp->peerdn = peerdn; /*XXX a static buffer... */ | |
1614 | } | |
1615 | else | |
1616 | tlsp->peerdn = NULL; | |
1617 | } | |
1618 | ||
1619 | ||
059ec3d9 PH |
1620 | |
1621 | ||
1622 | ||
1623 | /************************************************* | |
1624 | * Set up for verifying certificates * | |
1625 | *************************************************/ | |
1626 | ||
1627 | /* Called by both client and server startup | |
1628 | ||
1629 | Arguments: | |
7be682ca | 1630 | sctx SSL_CTX* to initialise |
059ec3d9 PH |
1631 | certs certs file or NULL |
1632 | crl CRL file or NULL | |
1633 | host NULL in a server; the remote host in a client | |
1634 | optional TRUE if called from a server for a host in tls_try_verify_hosts; | |
1635 | otherwise passed as FALSE | |
983207c1 | 1636 | cert_vfy_cb Callback function for certificate verification |
059ec3d9 PH |
1637 | |
1638 | Returns: OK/DEFER/FAIL | |
1639 | */ | |
1640 | ||
1641 | static int | |
983207c1 JH |
1642 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
1643 | int (*cert_vfy_cb)(int, X509_STORE_CTX *) ) | |
059ec3d9 PH |
1644 | { |
1645 | uschar *expcerts, *expcrl; | |
1646 | ||
1647 | if (!expand_check(certs, US"tls_verify_certificates", &expcerts)) | |
1648 | return DEFER; | |
1649 | ||
10a831a3 | 1650 | if (expcerts && *expcerts) |
059ec3d9 | 1651 | { |
10a831a3 JH |
1652 | /* Tell the library to use its compiled-in location for the system default |
1653 | CA bundle. Then add the ones specified in the config, if any. */ | |
cb1d7830 | 1654 | |
10a831a3 JH |
1655 | if (!SSL_CTX_set_default_verify_paths(sctx)) |
1656 | return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL); | |
1657 | ||
1658 | if (Ustrcmp(expcerts, "system") != 0) | |
059ec3d9 | 1659 | { |
cb1d7830 JH |
1660 | struct stat statbuf; |
1661 | ||
cb1d7830 JH |
1662 | if (Ustat(expcerts, &statbuf) < 0) |
1663 | { | |
1664 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1665 | "failed to stat %s for certificates", expcerts); | |
1666 | return DEFER; | |
1667 | } | |
059ec3d9 | 1668 | else |
059ec3d9 | 1669 | { |
cb1d7830 JH |
1670 | uschar *file, *dir; |
1671 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
1672 | { file = NULL; dir = expcerts; } | |
1673 | else | |
1674 | { file = expcerts; dir = NULL; } | |
1675 | ||
1676 | /* If a certificate file is empty, the next function fails with an | |
1677 | unhelpful error message. If we skip it, we get the correct behaviour (no | |
1678 | certificates are recognized, but the error message is still misleading (it | |
1679 | says no certificate was supplied.) But this is better. */ | |
1680 | ||
f2f2c91b JH |
1681 | if ( (!file || statbuf.st_size > 0) |
1682 | && !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) | |
cb1d7830 JH |
1683 | return tls_error(US"SSL_CTX_load_verify_locations", host, NULL); |
1684 | ||
1685 | /* Load the list of CAs for which we will accept certs, for sending | |
1686 | to the client. This is only for the one-file tls_verify_certificates | |
1687 | variant. | |
1688 | If a list isn't loaded into the server, but | |
1689 | some verify locations are set, the server end appears to make | |
1690 | a wildcard reqest for client certs. | |
10a831a3 | 1691 | Meanwhile, the client library as default behaviour *ignores* the list |
cb1d7830 JH |
1692 | we send over the wire - see man SSL_CTX_set_client_cert_cb. |
1693 | Because of this, and that the dir variant is likely only used for | |
1694 | the public-CA bundle (not for a private CA), not worth fixing. | |
1695 | */ | |
f2f2c91b | 1696 | if (file) |
cb1d7830 JH |
1697 | { |
1698 | STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file); | |
f2f2c91b JH |
1699 | |
1700 | DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", | |
cb1d7830 JH |
1701 | sk_X509_NAME_num(names)); |
1702 | SSL_CTX_set_client_CA_list(sctx, names); | |
1703 | } | |
059ec3d9 PH |
1704 | } |
1705 | } | |
1706 | ||
1707 | /* Handle a certificate revocation list. */ | |
1708 | ||
10a831a3 | 1709 | #if OPENSSL_VERSION_NUMBER > 0x00907000L |
059ec3d9 | 1710 | |
8b417f2c | 1711 | /* This bit of code is now the version supplied by Lars Mainka. (I have |
10a831a3 | 1712 | merely reformatted it into the Exim code style.) |
8b417f2c | 1713 | |
10a831a3 JH |
1714 | "From here I changed the code to add support for multiple crl's |
1715 | in pem format in one file or to support hashed directory entries in | |
1716 | pem format instead of a file. This method now uses the library function | |
1717 | X509_STORE_load_locations to add the CRL location to the SSL context. | |
1718 | OpenSSL will then handle the verify against CA certs and CRLs by | |
1719 | itself in the verify callback." */ | |
8b417f2c | 1720 | |
059ec3d9 | 1721 | if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER; |
10a831a3 | 1722 | if (expcrl && *expcrl) |
059ec3d9 | 1723 | { |
8b417f2c PH |
1724 | struct stat statbufcrl; |
1725 | if (Ustat(expcrl, &statbufcrl) < 0) | |
1726 | { | |
1727 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1728 | "failed to stat %s for certificates revocation lists", expcrl); | |
1729 | return DEFER; | |
1730 | } | |
1731 | else | |
059ec3d9 | 1732 | { |
8b417f2c PH |
1733 | /* is it a file or directory? */ |
1734 | uschar *file, *dir; | |
7be682ca | 1735 | X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx); |
8b417f2c | 1736 | if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR) |
059ec3d9 | 1737 | { |
8b417f2c PH |
1738 | file = NULL; |
1739 | dir = expcrl; | |
1740 | DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir); | |
059ec3d9 PH |
1741 | } |
1742 | else | |
1743 | { | |
8b417f2c PH |
1744 | file = expcrl; |
1745 | dir = NULL; | |
1746 | DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); | |
059ec3d9 | 1747 | } |
8b417f2c | 1748 | if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) |
7199e1ee | 1749 | return tls_error(US"X509_STORE_load_locations", host, NULL); |
8b417f2c PH |
1750 | |
1751 | /* setting the flags to check against the complete crl chain */ | |
1752 | ||
1753 | X509_STORE_set_flags(cvstore, | |
1754 | X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL); | |
059ec3d9 | 1755 | } |
059ec3d9 PH |
1756 | } |
1757 | ||
10a831a3 | 1758 | #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ |
059ec3d9 PH |
1759 | |
1760 | /* If verification is optional, don't fail if no certificate */ | |
1761 | ||
7be682ca | 1762 | SSL_CTX_set_verify(sctx, |
059ec3d9 | 1763 | SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT), |
983207c1 | 1764 | cert_vfy_cb); |
059ec3d9 PH |
1765 | } |
1766 | ||
1767 | return OK; | |
1768 | } | |
1769 | ||
1770 | ||
1771 | ||
1772 | /************************************************* | |
1773 | * Start a TLS session in a server * | |
1774 | *************************************************/ | |
1775 | ||
1776 | /* This is called when Exim is running as a server, after having received | |
1777 | the STARTTLS command. It must respond to that command, and then negotiate | |
1778 | a TLS session. | |
1779 | ||
1780 | Arguments: | |
1781 | require_ciphers allowed ciphers | |
1782 | ||
1783 | Returns: OK on success | |
1784 | DEFER for errors before the start of the negotiation | |
1785 | FAIL for errors during the negotation; the server can't | |
1786 | continue running. | |
1787 | */ | |
1788 | ||
1789 | int | |
17c76198 | 1790 | tls_server_start(const uschar *require_ciphers) |
059ec3d9 PH |
1791 | { |
1792 | int rc; | |
1793 | uschar *expciphers; | |
7be682ca | 1794 | tls_ext_ctx_cb *cbinfo; |
f69979cf | 1795 | static uschar peerdn[256]; |
817d9f57 | 1796 | static uschar cipherbuf[256]; |
059ec3d9 PH |
1797 | |
1798 | /* Check for previous activation */ | |
1799 | ||
817d9f57 | 1800 | if (tls_in.active >= 0) |
059ec3d9 | 1801 | { |
5ca6d115 | 1802 | tls_error(US"STARTTLS received after TLS started", NULL, US""); |
059ec3d9 PH |
1803 | smtp_printf("554 Already in TLS\r\n"); |
1804 | return FAIL; | |
1805 | } | |
1806 | ||
1807 | /* Initialize the SSL library. If it fails, it will already have logged | |
1808 | the error. */ | |
1809 | ||
817d9f57 | 1810 | rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey, |
f2de3a33 | 1811 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1812 | tls_ocsp_file, |
1813 | #endif | |
817d9f57 | 1814 | NULL, &server_static_cbinfo); |
059ec3d9 | 1815 | if (rc != OK) return rc; |
817d9f57 | 1816 | cbinfo = server_static_cbinfo; |
059ec3d9 PH |
1817 | |
1818 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers)) | |
1819 | return FAIL; | |
1820 | ||
1821 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
17c76198 PP |
1822 | were historically separated by underscores. So that I can use either form in my |
1823 | tests, and also for general convenience, we turn underscores into hyphens here. | |
1824 | */ | |
059ec3d9 PH |
1825 | |
1826 | if (expciphers != NULL) | |
1827 | { | |
1828 | uschar *s = expciphers; | |
1829 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1830 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1831 | if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) |
7199e1ee | 1832 | return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL); |
7be682ca | 1833 | cbinfo->server_cipher_list = expciphers; |
059ec3d9 PH |
1834 | } |
1835 | ||
1836 | /* If this is a host for which certificate verification is mandatory or | |
1837 | optional, set up appropriately. */ | |
1838 | ||
817d9f57 | 1839 | tls_in.certificate_verified = FALSE; |
53a7196b JH |
1840 | #ifdef EXPERIMENTAL_DANE |
1841 | tls_in.dane_verified = FALSE; | |
1842 | #endif | |
a2ff477a | 1843 | server_verify_callback_called = FALSE; |
059ec3d9 PH |
1844 | |
1845 | if (verify_check_host(&tls_verify_hosts) == OK) | |
1846 | { | |
983207c1 JH |
1847 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
1848 | FALSE, verify_callback_server); | |
059ec3d9 | 1849 | if (rc != OK) return rc; |
a2ff477a | 1850 | server_verify_optional = FALSE; |
059ec3d9 PH |
1851 | } |
1852 | else if (verify_check_host(&tls_try_verify_hosts) == OK) | |
1853 | { | |
983207c1 JH |
1854 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
1855 | TRUE, verify_callback_server); | |
059ec3d9 | 1856 | if (rc != OK) return rc; |
a2ff477a | 1857 | server_verify_optional = TRUE; |
059ec3d9 PH |
1858 | } |
1859 | ||
1860 | /* Prepare for new connection */ | |
1861 | ||
817d9f57 | 1862 | if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL); |
da3ad30d PP |
1863 | |
1864 | /* Warning: we used to SSL_clear(ssl) here, it was removed. | |
1865 | * | |
1866 | * With the SSL_clear(), we get strange interoperability bugs with | |
1867 | * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in | |
1868 | * OpenSSL itself, as a clear should not lead to inability to follow protocols. | |
1869 | * | |
1870 | * The SSL_clear() call is to let an existing SSL* be reused, typically after | |
1871 | * session shutdown. In this case, we have a brand new object and there's no | |
1872 | * obvious reason to immediately clear it. I'm guessing that this was | |
1873 | * originally added because of incomplete initialisation which the clear fixed, | |
1874 | * in some historic release. | |
1875 | */ | |
059ec3d9 PH |
1876 | |
1877 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
1878 | on connection, where outputting anything now upsets the clients and tends to | |
1879 | make them disconnect. We need to have an explicit fflush() here, to force out | |
1880 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
1881 | mode, the fflush() happens when smtp_getc() is called. */ | |
1882 | ||
817d9f57 JH |
1883 | SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1884 | if (!tls_in.on_connect) | |
059ec3d9 PH |
1885 | { |
1886 | smtp_printf("220 TLS go ahead\r\n"); | |
1887 | fflush(smtp_out); | |
1888 | } | |
1889 | ||
1890 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
1891 | that the OpenSSL library doesn't. */ | |
1892 | ||
817d9f57 JH |
1893 | SSL_set_wfd(server_ssl, fileno(smtp_out)); |
1894 | SSL_set_rfd(server_ssl, fileno(smtp_in)); | |
1895 | SSL_set_accept_state(server_ssl); | |
059ec3d9 PH |
1896 | |
1897 | DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); | |
1898 | ||
1899 | sigalrm_seen = FALSE; | |
1900 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 | 1901 | rc = SSL_accept(server_ssl); |
059ec3d9 PH |
1902 | alarm(0); |
1903 | ||
1904 | if (rc <= 0) | |
1905 | { | |
7199e1ee | 1906 | tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL); |
77bb000f PP |
1907 | if (ERR_get_error() == 0) |
1908 | log_write(0, LOG_MAIN, | |
a053d125 | 1909 | "TLS client disconnected cleanly (rejected our certificate?)"); |
059ec3d9 PH |
1910 | return FAIL; |
1911 | } | |
1912 | ||
1913 | DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); | |
1914 | ||
1915 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
1916 | and initialize things. */ | |
1917 | ||
f69979cf JH |
1918 | peer_cert(server_ssl, &tls_in, peerdn, sizeof(peerdn)); |
1919 | ||
817d9f57 JH |
1920 | construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits); |
1921 | tls_in.cipher = cipherbuf; | |
059ec3d9 PH |
1922 | |
1923 | DEBUG(D_tls) | |
1924 | { | |
1925 | uschar buf[2048]; | |
817d9f57 | 1926 | if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL) |
059ec3d9 PH |
1927 | debug_printf("Shared ciphers: %s\n", buf); |
1928 | } | |
1929 | ||
9d1c15ef JH |
1930 | /* Record the certificate we presented */ |
1931 | { | |
1932 | X509 * crt = SSL_get_certificate(server_ssl); | |
1933 | tls_in.ourcert = crt ? X509_dup(crt) : NULL; | |
1934 | } | |
059ec3d9 | 1935 | |
817d9f57 JH |
1936 | /* Only used by the server-side tls (tls_in), including tls_getc. |
1937 | Client-side (tls_out) reads (seem to?) go via | |
1938 | smtp_read_response()/ip_recv(). | |
1939 | Hence no need to duplicate for _in and _out. | |
1940 | */ | |
059ec3d9 PH |
1941 | ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
1942 | ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; | |
1943 | ssl_xfer_eof = ssl_xfer_error = 0; | |
1944 | ||
1945 | receive_getc = tls_getc; | |
584e96c6 | 1946 | receive_get_cache = tls_get_cache; |
059ec3d9 PH |
1947 | receive_ungetc = tls_ungetc; |
1948 | receive_feof = tls_feof; | |
1949 | receive_ferror = tls_ferror; | |
58eb016e | 1950 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 1951 | |
817d9f57 | 1952 | tls_in.active = fileno(smtp_out); |
059ec3d9 PH |
1953 | return OK; |
1954 | } | |
1955 | ||
1956 | ||
1957 | ||
1958 | ||
043b1248 JH |
1959 | static int |
1960 | tls_client_basic_ctx_init(SSL_CTX * ctx, | |
01a4a5c5 | 1961 | host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo |
043b1248 JH |
1962 | ) |
1963 | { | |
1964 | int rc; | |
94431adb | 1965 | /* stick to the old behaviour for compatibility if tls_verify_certificates is |
043b1248 JH |
1966 | set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only |
1967 | the specified host patterns if one of them is defined */ | |
1968 | ||
610ff438 JH |
1969 | if ( ( !ob->tls_verify_hosts |
1970 | && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) | |
1971 | ) | |
5130845b | 1972 | || (verify_check_given_host(&ob->tls_verify_hosts, host) == OK) |
aa2a70ba | 1973 | ) |
043b1248 | 1974 | client_verify_optional = FALSE; |
5130845b | 1975 | else if (verify_check_given_host(&ob->tls_try_verify_hosts, host) == OK) |
aa2a70ba JH |
1976 | client_verify_optional = TRUE; |
1977 | else | |
1978 | return OK; | |
1979 | ||
1980 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
1981 | ob->tls_crl, host, client_verify_optional, verify_callback_client)) != OK) | |
1982 | return rc; | |
043b1248 | 1983 | |
5130845b | 1984 | if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK) |
043b1248 | 1985 | { |
4af0d74a | 1986 | cbinfo->verify_cert_hostnames = |
8c5d388a | 1987 | #ifdef SUPPORT_I18N |
4af0d74a JH |
1988 | string_domain_utf8_to_alabel(host->name, NULL); |
1989 | #else | |
1990 | host->name; | |
1991 | #endif | |
aa2a70ba JH |
1992 | DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", |
1993 | cbinfo->verify_cert_hostnames); | |
043b1248 | 1994 | } |
043b1248 JH |
1995 | return OK; |
1996 | } | |
059ec3d9 | 1997 | |
fde080a4 JH |
1998 | |
1999 | #ifdef EXPERIMENTAL_DANE | |
fde080a4 JH |
2000 | static int |
2001 | dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa) | |
2002 | { | |
2003 | dns_record * rr; | |
2004 | dns_scan dnss; | |
2005 | const char * hostnames[2] = { CS host->name, NULL }; | |
2006 | int found = 0; | |
2007 | ||
2008 | if (DANESSL_init(ssl, NULL, hostnames) != 1) | |
2009 | return tls_error(US"hostnames load", host, NULL); | |
2010 | ||
2011 | for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); | |
2012 | rr; | |
2013 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) | |
2014 | ) if (rr->type == T_TLSA) | |
2015 | { | |
2016 | uschar * p = rr->data; | |
2017 | uint8_t usage, selector, mtype; | |
2018 | const char * mdname; | |
2019 | ||
fde080a4 | 2020 | usage = *p++; |
133d2546 JH |
2021 | |
2022 | /* Only DANE-TA(2) and DANE-EE(3) are supported */ | |
2023 | if (usage != 2 && usage != 3) continue; | |
2024 | ||
fde080a4 JH |
2025 | selector = *p++; |
2026 | mtype = *p++; | |
2027 | ||
2028 | switch (mtype) | |
2029 | { | |
133d2546 JH |
2030 | default: continue; /* Only match-types 0, 1, 2 are supported */ |
2031 | case 0: mdname = NULL; break; | |
2032 | case 1: mdname = "sha256"; break; | |
2033 | case 2: mdname = "sha512"; break; | |
fde080a4 JH |
2034 | } |
2035 | ||
133d2546 | 2036 | found++; |
fde080a4 JH |
2037 | switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3)) |
2038 | { | |
2039 | default: | |
fde080a4 | 2040 | return tls_error(US"tlsa load", host, NULL); |
c035b645 | 2041 | case 0: /* action not taken */ |
fde080a4 JH |
2042 | case 1: break; |
2043 | } | |
594706ea JH |
2044 | |
2045 | tls_out.tlsa_usage |= 1<<usage; | |
fde080a4 JH |
2046 | } |
2047 | ||
2048 | if (found) | |
2049 | return OK; | |
2050 | ||
133d2546 | 2051 | log_write(0, LOG_MAIN, "DANE error: No usable TLSA records"); |
6ebd79ec | 2052 | return DEFER; |
fde080a4 JH |
2053 | } |
2054 | #endif /*EXPERIMENTAL_DANE*/ | |
2055 | ||
2056 | ||
2057 | ||
059ec3d9 PH |
2058 | /************************************************* |
2059 | * Start a TLS session in a client * | |
2060 | *************************************************/ | |
2061 | ||
2062 | /* Called from the smtp transport after STARTTLS has been accepted. | |
2063 | ||
2064 | Argument: | |
2065 | fd the fd of the connection | |
2066 | host connected host (for messages) | |
83da1223 | 2067 | addr the first address |
a7538db1 | 2068 | tb transport (always smtp) |
0e66b3b6 | 2069 | tlsa_dnsa tlsa lookup, if DANE, else null |
059ec3d9 PH |
2070 | |
2071 | Returns: OK on success | |
2072 | FAIL otherwise - note that tls_error() will not give DEFER | |
2073 | because this is not a server | |
2074 | */ | |
2075 | ||
2076 | int | |
f5d78688 | 2077 | tls_client_start(int fd, host_item *host, address_item *addr, |
0e66b3b6 JH |
2078 | transport_instance *tb |
2079 | #ifdef EXPERIMENTAL_DANE | |
2080 | , dns_answer * tlsa_dnsa | |
2081 | #endif | |
2082 | ) | |
059ec3d9 | 2083 | { |
a7538db1 JH |
2084 | smtp_transport_options_block * ob = |
2085 | (smtp_transport_options_block *)tb->options_block; | |
f69979cf | 2086 | static uschar peerdn[256]; |
868f5672 | 2087 | uschar * expciphers; |
059ec3d9 | 2088 | int rc; |
817d9f57 | 2089 | static uschar cipherbuf[256]; |
043b1248 JH |
2090 | |
2091 | #ifndef DISABLE_OCSP | |
043b1248 | 2092 | BOOL request_ocsp = FALSE; |
6634ac8d | 2093 | BOOL require_ocsp = FALSE; |
043b1248 | 2094 | #endif |
043b1248 JH |
2095 | |
2096 | #ifdef EXPERIMENTAL_DANE | |
594706ea | 2097 | tls_out.tlsa_usage = 0; |
043b1248 JH |
2098 | #endif |
2099 | ||
f2de3a33 | 2100 | #ifndef DISABLE_OCSP |
043b1248 | 2101 | { |
4f59c424 JH |
2102 | # ifdef EXPERIMENTAL_DANE |
2103 | if ( tlsa_dnsa | |
2104 | && ob->hosts_request_ocsp[0] == '*' | |
2105 | && ob->hosts_request_ocsp[1] == '\0' | |
2106 | ) | |
2107 | { | |
2108 | /* Unchanged from default. Use a safer one under DANE */ | |
2109 | request_ocsp = TRUE; | |
2110 | ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} " | |
2111 | " {= {4}{$tls_out_tlsa_usage}} } " | |
2112 | " {*}{}}"; | |
2113 | } | |
2114 | # endif | |
2115 | ||
5130845b JH |
2116 | if ((require_ocsp = |
2117 | verify_check_given_host(&ob->hosts_require_ocsp, host) == OK)) | |
fca41d5a JH |
2118 | request_ocsp = TRUE; |
2119 | else | |
fca41d5a | 2120 | # ifdef EXPERIMENTAL_DANE |
4f59c424 | 2121 | if (!request_ocsp) |
fca41d5a | 2122 | # endif |
5130845b JH |
2123 | request_ocsp = |
2124 | verify_check_given_host(&ob->hosts_request_ocsp, host) == OK; | |
043b1248 | 2125 | } |
f5d78688 | 2126 | #endif |
059ec3d9 | 2127 | |
65867078 JH |
2128 | rc = tls_init(&client_ctx, host, NULL, |
2129 | ob->tls_certificate, ob->tls_privatekey, | |
f2de3a33 | 2130 | #ifndef DISABLE_OCSP |
44662487 | 2131 | (void *)(long)request_ocsp, |
3f7eeb86 | 2132 | #endif |
817d9f57 | 2133 | addr, &client_static_cbinfo); |
059ec3d9 PH |
2134 | if (rc != OK) return rc; |
2135 | ||
817d9f57 | 2136 | tls_out.certificate_verified = FALSE; |
a2ff477a | 2137 | client_verify_callback_called = FALSE; |
059ec3d9 | 2138 | |
65867078 JH |
2139 | if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers", |
2140 | &expciphers)) | |
059ec3d9 PH |
2141 | return FAIL; |
2142 | ||
2143 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
2144 | are separated by underscores. So that I can use either form in my tests, and | |
2145 | also for general convenience, we turn underscores into hyphens here. */ | |
2146 | ||
2147 | if (expciphers != NULL) | |
2148 | { | |
2149 | uschar *s = expciphers; | |
2150 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
2151 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 2152 | if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers)) |
7199e1ee | 2153 | return tls_error(US"SSL_CTX_set_cipher_list", host, NULL); |
059ec3d9 PH |
2154 | } |
2155 | ||
043b1248 | 2156 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 | 2157 | if (tlsa_dnsa) |
a63be306 | 2158 | { |
02af313d JH |
2159 | SSL_CTX_set_verify(client_ctx, |
2160 | SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, | |
2161 | verify_callback_client_dane); | |
e5cccda9 | 2162 | |
043b1248 | 2163 | if (!DANESSL_library_init()) |
b4161d10 | 2164 | return tls_error(US"library init", host, NULL); |
043b1248 | 2165 | if (DANESSL_CTX_init(client_ctx) <= 0) |
b4161d10 | 2166 | return tls_error(US"context init", host, NULL); |
043b1248 JH |
2167 | } |
2168 | else | |
e51c7be2 | 2169 | |
043b1248 JH |
2170 | #endif |
2171 | ||
01a4a5c5 JH |
2172 | if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob, client_static_cbinfo)) |
2173 | != OK) | |
65867078 | 2174 | return rc; |
059ec3d9 | 2175 | |
65867078 JH |
2176 | if ((client_ssl = SSL_new(client_ctx)) == NULL) |
2177 | return tls_error(US"SSL_new", host, NULL); | |
817d9f57 JH |
2178 | SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx)); |
2179 | SSL_set_fd(client_ssl, fd); | |
2180 | SSL_set_connect_state(client_ssl); | |
059ec3d9 | 2181 | |
65867078 | 2182 | if (ob->tls_sni) |
3f0945ff | 2183 | { |
65867078 | 2184 | if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni)) |
3f0945ff | 2185 | return FAIL; |
ec4b68e5 | 2186 | if (tls_out.sni == NULL) |
2c9a0e86 PP |
2187 | { |
2188 | DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n"); | |
2189 | } | |
ec4b68e5 | 2190 | else if (!Ustrlen(tls_out.sni)) |
817d9f57 | 2191 | tls_out.sni = NULL; |
3f0945ff PP |
2192 | else |
2193 | { | |
35731706 | 2194 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 JH |
2195 | DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni); |
2196 | SSL_set_tlsext_host_name(client_ssl, tls_out.sni); | |
35731706 | 2197 | #else |
66802652 | 2198 | log_write(0, LOG_MAIN, "SNI unusable with this OpenSSL library version; ignoring \"%s\"\n", |
02d9264f | 2199 | tls_out.sni); |
35731706 | 2200 | #endif |
3f0945ff PP |
2201 | } |
2202 | } | |
2203 | ||
594706ea | 2204 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 JH |
2205 | if (tlsa_dnsa) |
2206 | if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa)) != OK) | |
594706ea JH |
2207 | return rc; |
2208 | #endif | |
2209 | ||
f2de3a33 | 2210 | #ifndef DISABLE_OCSP |
f5d78688 JH |
2211 | /* Request certificate status at connection-time. If the server |
2212 | does OCSP stapling we will get the callback (set in tls_init()) */ | |
b50c8b84 | 2213 | # ifdef EXPERIMENTAL_DANE |
594706ea JH |
2214 | if (request_ocsp) |
2215 | { | |
2216 | const uschar * s; | |
41afb5cb JH |
2217 | if ( ((s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage")) |
2218 | || ((s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage")) | |
594706ea JH |
2219 | ) |
2220 | { /* Re-eval now $tls_out_tlsa_usage is populated. If | |
2221 | this means we avoid the OCSP request, we wasted the setup | |
2222 | cost in tls_init(). */ | |
5130845b JH |
2223 | require_ocsp = verify_check_given_host(&ob->hosts_require_ocsp, host) == OK; |
2224 | request_ocsp = require_ocsp | |
2225 | || verify_check_given_host(&ob->hosts_request_ocsp, host) == OK; | |
594706ea JH |
2226 | } |
2227 | } | |
b50c8b84 JH |
2228 | # endif |
2229 | ||
44662487 JH |
2230 | if (request_ocsp) |
2231 | { | |
f5d78688 | 2232 | SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp); |
44662487 JH |
2233 | client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp; |
2234 | tls_out.ocsp = OCSP_NOT_RESP; | |
2235 | } | |
f5d78688 JH |
2236 | #endif |
2237 | ||
0cbf2b82 | 2238 | #ifndef DISABLE_EVENT |
774ef2d7 | 2239 | client_static_cbinfo->event_action = tb->event_action; |
a7538db1 | 2240 | #endif |
043b1248 | 2241 | |
059ec3d9 PH |
2242 | /* There doesn't seem to be a built-in timeout on connection. */ |
2243 | ||
2244 | DEBUG(D_tls) debug_printf("Calling SSL_connect\n"); | |
2245 | sigalrm_seen = FALSE; | |
65867078 | 2246 | alarm(ob->command_timeout); |
817d9f57 | 2247 | rc = SSL_connect(client_ssl); |
059ec3d9 PH |
2248 | alarm(0); |
2249 | ||
043b1248 | 2250 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 | 2251 | if (tlsa_dnsa) |
fde080a4 | 2252 | DANESSL_cleanup(client_ssl); |
043b1248 JH |
2253 | #endif |
2254 | ||
059ec3d9 | 2255 | if (rc <= 0) |
7199e1ee | 2256 | return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL); |
059ec3d9 PH |
2257 | |
2258 | DEBUG(D_tls) debug_printf("SSL_connect succeeded\n"); | |
2259 | ||
f69979cf | 2260 | peer_cert(client_ssl, &tls_out, peerdn, sizeof(peerdn)); |
059ec3d9 | 2261 | |
817d9f57 JH |
2262 | construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits); |
2263 | tls_out.cipher = cipherbuf; | |
059ec3d9 | 2264 | |
9d1c15ef JH |
2265 | /* Record the certificate we presented */ |
2266 | { | |
2267 | X509 * crt = SSL_get_certificate(client_ssl); | |
2268 | tls_out.ourcert = crt ? X509_dup(crt) : NULL; | |
2269 | } | |
2270 | ||
817d9f57 | 2271 | tls_out.active = fd; |
059ec3d9 PH |
2272 | return OK; |
2273 | } | |
2274 | ||
2275 | ||
2276 | ||
2277 | ||
2278 | ||
2279 | /************************************************* | |
2280 | * TLS version of getc * | |
2281 | *************************************************/ | |
2282 | ||
2283 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
2284 | it refills the buffer via the SSL reading function. | |
2285 | ||
2286 | Arguments: none | |
2287 | Returns: the next character or EOF | |
817d9f57 JH |
2288 | |
2289 | Only used by the server-side TLS. | |
059ec3d9 PH |
2290 | */ |
2291 | ||
2292 | int | |
2293 | tls_getc(void) | |
2294 | { | |
2295 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) | |
2296 | { | |
2297 | int error; | |
2298 | int inbytes; | |
2299 | ||
817d9f57 | 2300 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl, |
c80c5570 | 2301 | ssl_xfer_buffer, ssl_xfer_buffer_size); |
059ec3d9 PH |
2302 | |
2303 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 JH |
2304 | inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size); |
2305 | error = SSL_get_error(server_ssl, inbytes); | |
059ec3d9 PH |
2306 | alarm(0); |
2307 | ||
2308 | /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been | |
2309 | closed down, not that the socket itself has been closed down. Revert to | |
2310 | non-SSL handling. */ | |
2311 | ||
2312 | if (error == SSL_ERROR_ZERO_RETURN) | |
2313 | { | |
2314 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2315 | ||
2316 | receive_getc = smtp_getc; | |
584e96c6 | 2317 | receive_get_cache = smtp_get_cache; |
059ec3d9 PH |
2318 | receive_ungetc = smtp_ungetc; |
2319 | receive_feof = smtp_feof; | |
2320 | receive_ferror = smtp_ferror; | |
58eb016e | 2321 | receive_smtp_buffered = smtp_buffered; |
059ec3d9 | 2322 | |
817d9f57 JH |
2323 | SSL_free(server_ssl); |
2324 | server_ssl = NULL; | |
2325 | tls_in.active = -1; | |
2326 | tls_in.bits = 0; | |
2327 | tls_in.cipher = NULL; | |
2328 | tls_in.peerdn = NULL; | |
2329 | tls_in.sni = NULL; | |
059ec3d9 PH |
2330 | |
2331 | return smtp_getc(); | |
2332 | } | |
2333 | ||
2334 | /* Handle genuine errors */ | |
2335 | ||
ba084640 PP |
2336 | else if (error == SSL_ERROR_SSL) |
2337 | { | |
2338 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
89dd51cd | 2339 | log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); |
ba084640 PP |
2340 | ssl_xfer_error = 1; |
2341 | return EOF; | |
2342 | } | |
2343 | ||
059ec3d9 PH |
2344 | else if (error != SSL_ERROR_NONE) |
2345 | { | |
2346 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
2347 | ssl_xfer_error = 1; | |
2348 | return EOF; | |
2349 | } | |
c80c5570 | 2350 | |
80a47a2c TK |
2351 | #ifndef DISABLE_DKIM |
2352 | dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); | |
2353 | #endif | |
059ec3d9 PH |
2354 | ssl_xfer_buffer_hwm = inbytes; |
2355 | ssl_xfer_buffer_lwm = 0; | |
2356 | } | |
2357 | ||
2358 | /* Something in the buffer; return next uschar */ | |
2359 | ||
2360 | return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; | |
2361 | } | |
2362 | ||
584e96c6 JH |
2363 | void |
2364 | tls_get_cache() | |
2365 | { | |
9960d1e5 | 2366 | #ifndef DISABLE_DKIM |
584e96c6 JH |
2367 | int n = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm; |
2368 | if (n > 0) | |
2369 | dkim_exim_verify_feed(ssl_xfer_buffer+ssl_xfer_buffer_lwm, n); | |
584e96c6 | 2370 | #endif |
9960d1e5 | 2371 | } |
584e96c6 | 2372 | |
059ec3d9 PH |
2373 | |
2374 | ||
2375 | /************************************************* | |
2376 | * Read bytes from TLS channel * | |
2377 | *************************************************/ | |
2378 | ||
2379 | /* | |
2380 | Arguments: | |
2381 | buff buffer of data | |
2382 | len size of buffer | |
2383 | ||
2384 | Returns: the number of bytes read | |
2385 | -1 after a failed read | |
817d9f57 JH |
2386 | |
2387 | Only used by the client-side TLS. | |
059ec3d9 PH |
2388 | */ |
2389 | ||
2390 | int | |
389ca47a | 2391 | tls_read(BOOL is_server, uschar *buff, size_t len) |
059ec3d9 | 2392 | { |
389ca47a | 2393 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 PH |
2394 | int inbytes; |
2395 | int error; | |
2396 | ||
389ca47a | 2397 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl, |
c80c5570 | 2398 | buff, (unsigned int)len); |
059ec3d9 | 2399 | |
389ca47a JH |
2400 | inbytes = SSL_read(ssl, CS buff, len); |
2401 | error = SSL_get_error(ssl, inbytes); | |
059ec3d9 PH |
2402 | |
2403 | if (error == SSL_ERROR_ZERO_RETURN) | |
2404 | { | |
2405 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2406 | return -1; | |
2407 | } | |
2408 | else if (error != SSL_ERROR_NONE) | |
2409 | { | |
2410 | return -1; | |
2411 | } | |
2412 | ||
2413 | return inbytes; | |
2414 | } | |
2415 | ||
2416 | ||
2417 | ||
2418 | ||
2419 | ||
2420 | /************************************************* | |
2421 | * Write bytes down TLS channel * | |
2422 | *************************************************/ | |
2423 | ||
2424 | /* | |
2425 | Arguments: | |
817d9f57 | 2426 | is_server channel specifier |
059ec3d9 PH |
2427 | buff buffer of data |
2428 | len number of bytes | |
2429 | ||
2430 | Returns: the number of bytes after a successful write, | |
2431 | -1 after a failed write | |
817d9f57 JH |
2432 | |
2433 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2434 | */ |
2435 | ||
2436 | int | |
817d9f57 | 2437 | tls_write(BOOL is_server, const uschar *buff, size_t len) |
059ec3d9 PH |
2438 | { |
2439 | int outbytes; | |
2440 | int error; | |
2441 | int left = len; | |
817d9f57 | 2442 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 | 2443 | |
c80c5570 | 2444 | DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left); |
059ec3d9 PH |
2445 | while (left > 0) |
2446 | { | |
c80c5570 | 2447 | DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left); |
059ec3d9 PH |
2448 | outbytes = SSL_write(ssl, CS buff, left); |
2449 | error = SSL_get_error(ssl, outbytes); | |
2450 | DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error); | |
2451 | switch (error) | |
2452 | { | |
2453 | case SSL_ERROR_SSL: | |
96f5fe4c JH |
2454 | ERR_error_string(ERR_get_error(), ssl_errstring); |
2455 | log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); | |
2456 | return -1; | |
059ec3d9 PH |
2457 | |
2458 | case SSL_ERROR_NONE: | |
96f5fe4c JH |
2459 | left -= outbytes; |
2460 | buff += outbytes; | |
2461 | break; | |
059ec3d9 PH |
2462 | |
2463 | case SSL_ERROR_ZERO_RETURN: | |
96f5fe4c JH |
2464 | log_write(0, LOG_MAIN, "SSL channel closed on write"); |
2465 | return -1; | |
059ec3d9 | 2466 | |
817d9f57 | 2467 | case SSL_ERROR_SYSCALL: |
96f5fe4c JH |
2468 | log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", |
2469 | sender_fullhost ? sender_fullhost : US"<unknown>", | |
2470 | strerror(errno)); | |
2471 | return -1; | |
817d9f57 | 2472 | |
059ec3d9 | 2473 | default: |
96f5fe4c JH |
2474 | log_write(0, LOG_MAIN, "SSL_write error %d", error); |
2475 | return -1; | |
059ec3d9 PH |
2476 | } |
2477 | } | |
2478 | return len; | |
2479 | } | |
2480 | ||
2481 | ||
2482 | ||
2483 | /************************************************* | |
2484 | * Close down a TLS session * | |
2485 | *************************************************/ | |
2486 | ||
2487 | /* This is also called from within a delivery subprocess forked from the | |
2488 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
2489 | would tamper with the SSL session in the parent process). | |
2490 | ||
2491 | Arguments: TRUE if SSL_shutdown is to be called | |
2492 | Returns: nothing | |
817d9f57 JH |
2493 | |
2494 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2495 | */ |
2496 | ||
2497 | void | |
817d9f57 | 2498 | tls_close(BOOL is_server, BOOL shutdown) |
059ec3d9 | 2499 | { |
817d9f57 | 2500 | SSL **sslp = is_server ? &server_ssl : &client_ssl; |
389ca47a | 2501 | int *fdp = is_server ? &tls_in.active : &tls_out.active; |
817d9f57 JH |
2502 | |
2503 | if (*fdp < 0) return; /* TLS was not active */ | |
059ec3d9 PH |
2504 | |
2505 | if (shutdown) | |
2506 | { | |
2507 | DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n"); | |
817d9f57 | 2508 | SSL_shutdown(*sslp); |
059ec3d9 PH |
2509 | } |
2510 | ||
817d9f57 JH |
2511 | SSL_free(*sslp); |
2512 | *sslp = NULL; | |
059ec3d9 | 2513 | |
817d9f57 | 2514 | *fdp = -1; |
059ec3d9 PH |
2515 | } |
2516 | ||
36f12725 NM |
2517 | |
2518 | ||
2519 | ||
3375e053 PP |
2520 | /************************************************* |
2521 | * Let tls_require_ciphers be checked at startup * | |
2522 | *************************************************/ | |
2523 | ||
2524 | /* The tls_require_ciphers option, if set, must be something which the | |
2525 | library can parse. | |
2526 | ||
2527 | Returns: NULL on success, or error message | |
2528 | */ | |
2529 | ||
2530 | uschar * | |
2531 | tls_validate_require_cipher(void) | |
2532 | { | |
2533 | SSL_CTX *ctx; | |
2534 | uschar *s, *expciphers, *err; | |
2535 | ||
2536 | /* this duplicates from tls_init(), we need a better "init just global | |
2537 | state, for no specific purpose" singleton function of our own */ | |
2538 | ||
2539 | SSL_load_error_strings(); | |
2540 | OpenSSL_add_ssl_algorithms(); | |
2541 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
2542 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the | |
2543 | list of available digests. */ | |
2544 | EVP_add_digest(EVP_sha256()); | |
2545 | #endif | |
2546 | ||
2547 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
2548 | return NULL; | |
2549 | ||
2550 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers)) | |
2551 | return US"failed to expand tls_require_ciphers"; | |
2552 | ||
2553 | if (!(expciphers && *expciphers)) | |
2554 | return NULL; | |
2555 | ||
2556 | /* normalisation ripped from above */ | |
2557 | s = expciphers; | |
2558 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
2559 | ||
2560 | err = NULL; | |
2561 | ||
2562 | ctx = SSL_CTX_new(SSLv23_server_method()); | |
2563 | if (!ctx) | |
2564 | { | |
2565 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2566 | return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring); | |
2567 | } | |
2568 | ||
2569 | DEBUG(D_tls) | |
2570 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
2571 | ||
2572 | if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) | |
2573 | { | |
2574 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2575 | err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers); | |
2576 | } | |
2577 | ||
2578 | SSL_CTX_free(ctx); | |
2579 | ||
2580 | return err; | |
2581 | } | |
2582 | ||
2583 | ||
2584 | ||
2585 | ||
36f12725 NM |
2586 | /************************************************* |
2587 | * Report the library versions. * | |
2588 | *************************************************/ | |
2589 | ||
2590 | /* There have historically been some issues with binary compatibility in | |
2591 | OpenSSL libraries; if Exim (like many other applications) is built against | |
2592 | one version of OpenSSL but the run-time linker picks up another version, | |
2593 | it can result in serious failures, including crashing with a SIGSEGV. So | |
2594 | report the version found by the compiler and the run-time version. | |
2595 | ||
f64a1e23 PP |
2596 | Note: some OS vendors backport security fixes without changing the version |
2597 | number/string, and the version date remains unchanged. The _build_ date | |
2598 | will change, so we can more usefully assist with version diagnosis by also | |
2599 | reporting the build date. | |
2600 | ||
36f12725 NM |
2601 | Arguments: a FILE* to print the results to |
2602 | Returns: nothing | |
2603 | */ | |
2604 | ||
2605 | void | |
2606 | tls_version_report(FILE *f) | |
2607 | { | |
754a0503 | 2608 | fprintf(f, "Library version: OpenSSL: Compile: %s\n" |
f64a1e23 PP |
2609 | " Runtime: %s\n" |
2610 | " : %s\n", | |
754a0503 | 2611 | OPENSSL_VERSION_TEXT, |
f64a1e23 PP |
2612 | SSLeay_version(SSLEAY_VERSION), |
2613 | SSLeay_version(SSLEAY_BUILT_ON)); | |
2614 | /* third line is 38 characters for the %s and the line is 73 chars long; | |
2615 | the OpenSSL output includes a "built on: " prefix already. */ | |
36f12725 NM |
2616 | } |
2617 | ||
9e3331ea TK |
2618 | |
2619 | ||
2620 | ||
2621 | /************************************************* | |
17c76198 | 2622 | * Random number generation * |
9e3331ea TK |
2623 | *************************************************/ |
2624 | ||
2625 | /* Pseudo-random number generation. The result is not expected to be | |
2626 | cryptographically strong but not so weak that someone will shoot themselves | |
2627 | in the foot using it as a nonce in input in some email header scheme or | |
2628 | whatever weirdness they'll twist this into. The result should handle fork() | |
2629 | and avoid repeating sequences. OpenSSL handles that for us. | |
2630 | ||
2631 | Arguments: | |
2632 | max range maximum | |
2633 | Returns a random number in range [0, max-1] | |
2634 | */ | |
2635 | ||
2636 | int | |
17c76198 | 2637 | vaguely_random_number(int max) |
9e3331ea TK |
2638 | { |
2639 | unsigned int r; | |
2640 | int i, needed_len; | |
de6135a0 PP |
2641 | static pid_t pidlast = 0; |
2642 | pid_t pidnow; | |
9e3331ea TK |
2643 | uschar *p; |
2644 | uschar smallbuf[sizeof(r)]; | |
2645 | ||
2646 | if (max <= 1) | |
2647 | return 0; | |
2648 | ||
de6135a0 PP |
2649 | pidnow = getpid(); |
2650 | if (pidnow != pidlast) | |
2651 | { | |
2652 | /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state | |
2653 | is unique for each thread", this doesn't apparently apply across processes, | |
2654 | so our own warning from vaguely_random_number_fallback() applies here too. | |
2655 | Fix per PostgreSQL. */ | |
2656 | if (pidlast != 0) | |
2657 | RAND_cleanup(); | |
2658 | pidlast = pidnow; | |
2659 | } | |
2660 | ||
9e3331ea TK |
2661 | /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ |
2662 | if (!RAND_status()) | |
2663 | { | |
2664 | randstuff r; | |
2665 | gettimeofday(&r.tv, NULL); | |
2666 | r.p = getpid(); | |
2667 | ||
2668 | RAND_seed((uschar *)(&r), sizeof(r)); | |
2669 | } | |
2670 | /* We're after pseudo-random, not random; if we still don't have enough data | |
2671 | in the internal PRNG then our options are limited. We could sleep and hope | |
2672 | for entropy to come along (prayer technique) but if the system is so depleted | |
2673 | in the first place then something is likely to just keep taking it. Instead, | |
2674 | we'll just take whatever little bit of pseudo-random we can still manage to | |
2675 | get. */ | |
2676 | ||
2677 | needed_len = sizeof(r); | |
2678 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
2679 | asked for a number less than 10. */ | |
2680 | for (r = max, i = 0; r; ++i) | |
2681 | r >>= 1; | |
2682 | i = (i + 7) / 8; | |
2683 | if (i < needed_len) | |
2684 | needed_len = i; | |
2685 | ||
c8dfb21d | 2686 | #ifdef EXIM_HAVE_RAND_PSEUDO |
9e3331ea | 2687 | /* We do not care if crypto-strong */ |
17c76198 | 2688 | i = RAND_pseudo_bytes(smallbuf, needed_len); |
c8dfb21d JH |
2689 | #else |
2690 | i = RAND_bytes(smallbuf, needed_len); | |
2691 | #endif | |
2692 | ||
17c76198 PP |
2693 | if (i < 0) |
2694 | { | |
2695 | DEBUG(D_all) | |
2696 | debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n"); | |
2697 | return vaguely_random_number_fallback(max); | |
2698 | } | |
2699 | ||
9e3331ea TK |
2700 | r = 0; |
2701 | for (p = smallbuf; needed_len; --needed_len, ++p) | |
2702 | { | |
2703 | r *= 256; | |
2704 | r += *p; | |
2705 | } | |
2706 | ||
2707 | /* We don't particularly care about weighted results; if someone wants | |
2708 | smooth distribution and cares enough then they should submit a patch then. */ | |
2709 | return r % max; | |
2710 | } | |
2711 | ||
77bb000f PP |
2712 | |
2713 | ||
2714 | ||
2715 | /************************************************* | |
2716 | * OpenSSL option parse * | |
2717 | *************************************************/ | |
2718 | ||
2719 | /* Parse one option for tls_openssl_options_parse below | |
2720 | ||
2721 | Arguments: | |
2722 | name one option name | |
2723 | value place to store a value for it | |
2724 | Returns success or failure in parsing | |
2725 | */ | |
2726 | ||
2727 | struct exim_openssl_option { | |
2728 | uschar *name; | |
2729 | long value; | |
2730 | }; | |
2731 | /* We could use a macro to expand, but we need the ifdef and not all the | |
2732 | options document which version they were introduced in. Policylet: include | |
2733 | all options unless explicitly for DTLS, let the administrator choose which | |
2734 | to apply. | |
2735 | ||
2736 | This list is current as of: | |
e2fbf4a2 PP |
2737 | ==> 1.0.1b <== |
2738 | Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev | |
2739 | */ | |
77bb000f PP |
2740 | static struct exim_openssl_option exim_openssl_options[] = { |
2741 | /* KEEP SORTED ALPHABETICALLY! */ | |
2742 | #ifdef SSL_OP_ALL | |
73a46702 | 2743 | { US"all", SSL_OP_ALL }, |
77bb000f PP |
2744 | #endif |
2745 | #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION | |
73a46702 | 2746 | { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, |
77bb000f PP |
2747 | #endif |
2748 | #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE | |
73a46702 | 2749 | { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, |
77bb000f PP |
2750 | #endif |
2751 | #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS | |
73a46702 | 2752 | { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, |
77bb000f PP |
2753 | #endif |
2754 | #ifdef SSL_OP_EPHEMERAL_RSA | |
73a46702 | 2755 | { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, |
77bb000f PP |
2756 | #endif |
2757 | #ifdef SSL_OP_LEGACY_SERVER_CONNECT | |
73a46702 | 2758 | { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, |
77bb000f PP |
2759 | #endif |
2760 | #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER | |
73a46702 | 2761 | { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, |
77bb000f PP |
2762 | #endif |
2763 | #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG | |
73a46702 | 2764 | { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, |
77bb000f PP |
2765 | #endif |
2766 | #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING | |
73a46702 | 2767 | { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, |
77bb000f PP |
2768 | #endif |
2769 | #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG | |
73a46702 | 2770 | { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, |
77bb000f PP |
2771 | #endif |
2772 | #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG | |
73a46702 | 2773 | { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, |
77bb000f | 2774 | #endif |
c80c5570 PP |
2775 | #ifdef SSL_OP_NO_COMPRESSION |
2776 | { US"no_compression", SSL_OP_NO_COMPRESSION }, | |
2777 | #endif | |
77bb000f | 2778 | #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |
73a46702 | 2779 | { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, |
77bb000f | 2780 | #endif |
c0c7b2da PP |
2781 | #ifdef SSL_OP_NO_SSLv2 |
2782 | { US"no_sslv2", SSL_OP_NO_SSLv2 }, | |
2783 | #endif | |
2784 | #ifdef SSL_OP_NO_SSLv3 | |
2785 | { US"no_sslv3", SSL_OP_NO_SSLv3 }, | |
2786 | #endif | |
2787 | #ifdef SSL_OP_NO_TICKET | |
2788 | { US"no_ticket", SSL_OP_NO_TICKET }, | |
2789 | #endif | |
2790 | #ifdef SSL_OP_NO_TLSv1 | |
2791 | { US"no_tlsv1", SSL_OP_NO_TLSv1 }, | |
2792 | #endif | |
c80c5570 PP |
2793 | #ifdef SSL_OP_NO_TLSv1_1 |
2794 | #if SSL_OP_NO_TLSv1_1 == 0x00000400L | |
2795 | /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */ | |
2796 | #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring | |
2797 | #else | |
2798 | { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 }, | |
2799 | #endif | |
2800 | #endif | |
2801 | #ifdef SSL_OP_NO_TLSv1_2 | |
2802 | { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 }, | |
2803 | #endif | |
e2fbf4a2 PP |
2804 | #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG |
2805 | { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG }, | |
2806 | #endif | |
77bb000f | 2807 | #ifdef SSL_OP_SINGLE_DH_USE |
73a46702 | 2808 | { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, |
77bb000f PP |
2809 | #endif |
2810 | #ifdef SSL_OP_SINGLE_ECDH_USE | |
73a46702 | 2811 | { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, |
77bb000f PP |
2812 | #endif |
2813 | #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG | |
73a46702 | 2814 | { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, |
77bb000f PP |
2815 | #endif |
2816 | #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG | |
73a46702 | 2817 | { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, |
77bb000f PP |
2818 | #endif |
2819 | #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG | |
73a46702 | 2820 | { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, |
77bb000f PP |
2821 | #endif |
2822 | #ifdef SSL_OP_TLS_D5_BUG | |
73a46702 | 2823 | { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, |
77bb000f PP |
2824 | #endif |
2825 | #ifdef SSL_OP_TLS_ROLLBACK_BUG | |
73a46702 | 2826 | { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, |
77bb000f PP |
2827 | #endif |
2828 | }; | |
2829 | static int exim_openssl_options_size = | |
2830 | sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option); | |
2831 | ||
c80c5570 | 2832 | |
77bb000f PP |
2833 | static BOOL |
2834 | tls_openssl_one_option_parse(uschar *name, long *value) | |
2835 | { | |
2836 | int first = 0; | |
2837 | int last = exim_openssl_options_size; | |
2838 | while (last > first) | |
2839 | { | |
2840 | int middle = (first + last)/2; | |
2841 | int c = Ustrcmp(name, exim_openssl_options[middle].name); | |
2842 | if (c == 0) | |
2843 | { | |
2844 | *value = exim_openssl_options[middle].value; | |
2845 | return TRUE; | |
2846 | } | |
2847 | else if (c > 0) | |
2848 | first = middle + 1; | |
2849 | else | |
2850 | last = middle; | |
2851 | } | |
2852 | return FALSE; | |
2853 | } | |
2854 | ||
2855 | ||
2856 | ||
2857 | ||
2858 | /************************************************* | |
2859 | * OpenSSL option parsing logic * | |
2860 | *************************************************/ | |
2861 | ||
2862 | /* OpenSSL has a number of compatibility options which an administrator might | |
2863 | reasonably wish to set. Interpret a list similarly to decode_bits(), so that | |
2864 | we look like log_selector. | |
2865 | ||
2866 | Arguments: | |
2867 | option_spec the administrator-supplied string of options | |
2868 | results ptr to long storage for the options bitmap | |
2869 | Returns success or failure | |
2870 | */ | |
2871 | ||
2872 | BOOL | |
2873 | tls_openssl_options_parse(uschar *option_spec, long *results) | |
2874 | { | |
2875 | long result, item; | |
2876 | uschar *s, *end; | |
2877 | uschar keep_c; | |
2878 | BOOL adding, item_parsed; | |
2879 | ||
0e944a0d | 2880 | result = 0L; |
b1770b6e | 2881 | /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed |
da3ad30d | 2882 | * from default because it increases BEAST susceptibility. */ |
f0f5a555 PP |
2883 | #ifdef SSL_OP_NO_SSLv2 |
2884 | result |= SSL_OP_NO_SSLv2; | |
2885 | #endif | |
a57b6200 JH |
2886 | #ifdef SSL_OP_SINGLE_DH_USE |
2887 | result |= SSL_OP_SINGLE_DH_USE; | |
2888 | #endif | |
77bb000f PP |
2889 | |
2890 | if (option_spec == NULL) | |
2891 | { | |
2892 | *results = result; | |
2893 | return TRUE; | |
2894 | } | |
2895 | ||
2896 | for (s=option_spec; *s != '\0'; /**/) | |
2897 | { | |
2898 | while (isspace(*s)) ++s; | |
2899 | if (*s == '\0') | |
2900 | break; | |
2901 | if (*s != '+' && *s != '-') | |
2902 | { | |
2903 | DEBUG(D_tls) debug_printf("malformed openssl option setting: " | |
0e944a0d | 2904 | "+ or - expected but found \"%s\"\n", s); |
77bb000f PP |
2905 | return FALSE; |
2906 | } | |
2907 | adding = *s++ == '+'; | |
2908 | for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; | |
2909 | keep_c = *end; | |
2910 | *end = '\0'; | |
2911 | item_parsed = tls_openssl_one_option_parse(s, &item); | |
96f5fe4c | 2912 | *end = keep_c; |
77bb000f PP |
2913 | if (!item_parsed) |
2914 | { | |
0e944a0d | 2915 | DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); |
77bb000f PP |
2916 | return FALSE; |
2917 | } | |
2918 | DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n", | |
2919 | adding ? "adding" : "removing", result, item, s); | |
2920 | if (adding) | |
2921 | result |= item; | |
2922 | else | |
2923 | result &= ~item; | |
77bb000f PP |
2924 | s = end; |
2925 | } | |
2926 | ||
2927 | *results = result; | |
2928 | return TRUE; | |
2929 | } | |
2930 | ||
9d1c15ef JH |
2931 | /* vi: aw ai sw=2 |
2932 | */ | |
059ec3d9 | 2933 | /* End of tls-openssl.c */ |