Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
d4e5e70b | 5 | /* Copyright (c) University of Cambridge 1995 - 2017 */ |
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 | |
6600985a | 49 | # define EXIM_HAVE_OPENSSL_DH_BITS |
c8dfb21d JH |
50 | #else |
51 | # define EXIM_HAVE_EPHEM_RSA_KEX | |
52 | # define EXIM_HAVE_RAND_PSEUDO | |
53 | #endif | |
54 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
55 | # define EXIM_HAVE_SHA256 | |
56 | #endif | |
34e3241d PP |
57 | |
58 | /* | |
59 | * X509_check_host provides sane certificate hostname checking, but was added | |
60 | * to OpenSSL late, after other projects forked off the code-base. So in | |
61 | * addition to guarding against the base version number, beware that LibreSSL | |
62 | * does not (at this time) support this function. | |
63 | * | |
64 | * If LibreSSL gains a different API, perhaps via libtls, then we'll probably | |
65 | * opt to disentangle and ask a LibreSSL user to provide glue for a third | |
66 | * crypto provider for libtls instead of continuing to tie the OpenSSL glue | |
67 | * into even twistier knots. If LibreSSL gains the same API, we can just | |
68 | * change this guard and punt the issue for a while longer. | |
69 | */ | |
70 | #ifndef LIBRESSL_VERSION_NUMBER | |
71 | # if OPENSSL_VERSION_NUMBER >= 0x010100000L | |
72 | # define EXIM_HAVE_OPENSSL_CHECKHOST | |
73 | # endif | |
74 | # if OPENSSL_VERSION_NUMBER >= 0x010000000L \ | |
2dfb468b | 75 | && (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L |
34e3241d PP |
76 | # define EXIM_HAVE_OPENSSL_CHECKHOST |
77 | # endif | |
11aa88b0 | 78 | #endif |
10ca4f1c | 79 | |
11aa88b0 RA |
80 | #if !defined(LIBRESSL_VERSION_NUMBER) \ |
81 | || LIBRESSL_VERSION_NUMBER >= 0x20010000L | |
10ca4f1c JH |
82 | # if !defined(OPENSSL_NO_ECDH) |
83 | # if OPENSSL_VERSION_NUMBER >= 0x0090800fL | |
84 | # define EXIM_HAVE_ECDH | |
85 | # endif | |
86 | # if OPENSSL_VERSION_NUMBER >= 0x10002000L | |
10ca4f1c JH |
87 | # define EXIM_HAVE_OPENSSL_EC_NIST2NID |
88 | # endif | |
89 | # endif | |
2dfb468b | 90 | #endif |
3bcbbbe2 | 91 | |
67791ce4 JH |
92 | #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP) |
93 | # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile" | |
94 | # define DISABLE_OCSP | |
95 | #endif | |
96 | ||
059ec3d9 PH |
97 | /* Structure for collecting random data for seeding. */ |
98 | ||
99 | typedef struct randstuff { | |
9e3331ea TK |
100 | struct timeval tv; |
101 | pid_t p; | |
059ec3d9 PH |
102 | } randstuff; |
103 | ||
104 | /* Local static variables */ | |
105 | ||
a2ff477a JH |
106 | static BOOL client_verify_callback_called = FALSE; |
107 | static BOOL server_verify_callback_called = FALSE; | |
059ec3d9 PH |
108 | static const uschar *sid_ctx = US"exim"; |
109 | ||
d4f09789 PP |
110 | /* We have three different contexts to care about. |
111 | ||
112 | Simple case: client, `client_ctx` | |
113 | As a client, we can be doing a callout or cut-through delivery while receiving | |
114 | a message. So we have a client context, which should have options initialised | |
115 | from the SMTP Transport. | |
116 | ||
117 | Server: | |
118 | There are two cases: with and without ServerNameIndication from the client. | |
119 | Given TLS SNI, we can be using different keys, certs and various other | |
120 | configuration settings, because they're re-expanded with $tls_sni set. This | |
121 | allows vhosting with TLS. This SNI is sent in the handshake. | |
122 | A client might not send SNI, so we need a fallback, and an initial setup too. | |
123 | So as a server, we start out using `server_ctx`. | |
124 | If SNI is sent by the client, then we as server, mid-negotiation, try to clone | |
125 | `server_sni` from `server_ctx` and then initialise settings by re-expanding | |
126 | configuration. | |
127 | */ | |
128 | ||
817d9f57 JH |
129 | static SSL_CTX *client_ctx = NULL; |
130 | static SSL_CTX *server_ctx = NULL; | |
131 | static SSL *client_ssl = NULL; | |
132 | static SSL *server_ssl = NULL; | |
389ca47a | 133 | |
35731706 | 134 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 | 135 | static SSL_CTX *server_sni = NULL; |
35731706 | 136 | #endif |
059ec3d9 PH |
137 | |
138 | static char ssl_errstring[256]; | |
139 | ||
140 | static int ssl_session_timeout = 200; | |
a2ff477a JH |
141 | static BOOL client_verify_optional = FALSE; |
142 | static BOOL server_verify_optional = FALSE; | |
059ec3d9 | 143 | |
f5d78688 | 144 | static BOOL reexpand_tls_files_for_sni = FALSE; |
059ec3d9 PH |
145 | |
146 | ||
7be682ca PP |
147 | typedef struct tls_ext_ctx_cb { |
148 | uschar *certificate; | |
149 | uschar *privatekey; | |
f2de3a33 | 150 | #ifndef DISABLE_OCSP |
f5d78688 | 151 | BOOL is_server; |
c3033f13 | 152 | STACK_OF(X509) *verify_stack; /* chain for verifying the proof */ |
f5d78688 JH |
153 | union { |
154 | struct { | |
155 | uschar *file; | |
156 | uschar *file_expanded; | |
157 | OCSP_RESPONSE *response; | |
158 | } server; | |
159 | struct { | |
44662487 JH |
160 | X509_STORE *verify_store; /* non-null if status requested */ |
161 | BOOL verify_required; | |
f5d78688 JH |
162 | } client; |
163 | } u_ocsp; | |
3f7eeb86 | 164 | #endif |
7be682ca PP |
165 | uschar *dhparam; |
166 | /* these are cached from first expand */ | |
167 | uschar *server_cipher_list; | |
168 | /* only passed down to tls_error: */ | |
169 | host_item *host; | |
55414b25 | 170 | const uschar * verify_cert_hostnames; |
0cbf2b82 | 171 | #ifndef DISABLE_EVENT |
a7538db1 JH |
172 | uschar * event_action; |
173 | #endif | |
7be682ca PP |
174 | } tls_ext_ctx_cb; |
175 | ||
176 | /* should figure out a cleanup of API to handle state preserved per | |
177 | implementation, for various reasons, which can be void * in the APIs. | |
178 | For now, we hack around it. */ | |
817d9f57 JH |
179 | tls_ext_ctx_cb *client_static_cbinfo = NULL; |
180 | tls_ext_ctx_cb *server_static_cbinfo = NULL; | |
7be682ca PP |
181 | |
182 | static int | |
983207c1 | 183 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
cf0c6164 | 184 | int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr ); |
059ec3d9 | 185 | |
3f7eeb86 | 186 | /* Callbacks */ |
3bcbbbe2 | 187 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
3f7eeb86 | 188 | static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg); |
3bcbbbe2 | 189 | #endif |
f2de3a33 | 190 | #ifndef DISABLE_OCSP |
f5d78688 | 191 | static int tls_server_stapling_cb(SSL *s, void *arg); |
3f7eeb86 PP |
192 | #endif |
193 | ||
059ec3d9 PH |
194 | |
195 | /************************************************* | |
196 | * Handle TLS error * | |
197 | *************************************************/ | |
198 | ||
199 | /* Called from lots of places when errors occur before actually starting to do | |
200 | the TLS handshake, that is, while the session is still in clear. Always returns | |
201 | DEFER for a server and FAIL for a client so that most calls can use "return | |
202 | tls_error(...)" to do this processing and then give an appropriate return. A | |
203 | single function is used for both server and client, because it is called from | |
204 | some shared functions. | |
205 | ||
206 | Argument: | |
207 | prefix text to include in the logged error | |
208 | host NULL if setting up a server; | |
209 | the connected host if setting up a client | |
7199e1ee | 210 | msg error message or NULL if we should ask OpenSSL |
cf0c6164 | 211 | errstr pointer to output error message |
059ec3d9 PH |
212 | |
213 | Returns: OK/DEFER/FAIL | |
214 | */ | |
215 | ||
216 | static int | |
cf0c6164 | 217 | tls_error(uschar * prefix, const host_item * host, uschar * msg, uschar ** errstr) |
059ec3d9 | 218 | { |
c562fd30 | 219 | if (!msg) |
7199e1ee TF |
220 | { |
221 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
cf0c6164 | 222 | msg = US ssl_errstring; |
7199e1ee TF |
223 | } |
224 | ||
cf0c6164 JH |
225 | if (errstr) *errstr = string_sprintf("(%s): %s", prefix, msg); |
226 | return host ? FAIL : DEFER; | |
059ec3d9 PH |
227 | } |
228 | ||
229 | ||
230 | ||
c8dfb21d | 231 | #ifdef EXIM_HAVE_EPHEM_RSA_KEX |
059ec3d9 PH |
232 | /************************************************* |
233 | * Callback to generate RSA key * | |
234 | *************************************************/ | |
235 | ||
236 | /* | |
237 | Arguments: | |
238 | s SSL connection | |
239 | export not used | |
240 | keylength keylength | |
241 | ||
242 | Returns: pointer to generated key | |
243 | */ | |
244 | ||
245 | static RSA * | |
246 | rsa_callback(SSL *s, int export, int keylength) | |
247 | { | |
248 | RSA *rsa_key; | |
c8dfb21d JH |
249 | #ifdef EXIM_HAVE_RSA_GENKEY_EX |
250 | BIGNUM *bn = BN_new(); | |
251 | #endif | |
252 | ||
059ec3d9 PH |
253 | export = export; /* Shut picky compilers up */ |
254 | DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength); | |
c8dfb21d JH |
255 | |
256 | #ifdef EXIM_HAVE_RSA_GENKEY_EX | |
257 | if ( !BN_set_word(bn, (unsigned long)RSA_F4) | |
f2cb6292 | 258 | || !(rsa_key = RSA_new()) |
c8dfb21d JH |
259 | || !RSA_generate_key_ex(rsa_key, keylength, bn, NULL) |
260 | ) | |
261 | #else | |
23bb6982 | 262 | if (!(rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL))) |
c8dfb21d JH |
263 | #endif |
264 | ||
059ec3d9 PH |
265 | { |
266 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
267 | log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s", | |
268 | ssl_errstring); | |
269 | return NULL; | |
270 | } | |
271 | return rsa_key; | |
272 | } | |
c8dfb21d | 273 | #endif |
059ec3d9 PH |
274 | |
275 | ||
276 | ||
f5d78688 | 277 | /* Extreme debug |
f2de3a33 | 278 | #ifndef DISABLE_OCSP |
f5d78688 JH |
279 | void |
280 | x509_store_dump_cert_s_names(X509_STORE * store) | |
281 | { | |
282 | STACK_OF(X509_OBJECT) * roots= store->objs; | |
283 | int i; | |
284 | static uschar name[256]; | |
285 | ||
286 | for(i= 0; i<sk_X509_OBJECT_num(roots); i++) | |
287 | { | |
288 | X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i); | |
289 | if(tmp_obj->type == X509_LU_X509) | |
290 | { | |
291 | X509 * current_cert= tmp_obj->data.x509; | |
292 | X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name)); | |
f69979cf | 293 | name[sizeof(name)-1] = '\0'; |
f5d78688 JH |
294 | debug_printf(" %s\n", name); |
295 | } | |
296 | } | |
297 | } | |
298 | #endif | |
299 | */ | |
300 | ||
059ec3d9 | 301 | |
0cbf2b82 | 302 | #ifndef DISABLE_EVENT |
f69979cf JH |
303 | static int |
304 | verify_event(tls_support * tlsp, X509 * cert, int depth, const uschar * dn, | |
305 | BOOL *calledp, const BOOL *optionalp, const uschar * what) | |
306 | { | |
307 | uschar * ev; | |
308 | uschar * yield; | |
309 | X509 * old_cert; | |
310 | ||
311 | ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action; | |
312 | if (ev) | |
313 | { | |
aaba7d03 | 314 | DEBUG(D_tls) debug_printf("verify_event: %s %d\n", what, depth); |
f69979cf JH |
315 | old_cert = tlsp->peercert; |
316 | tlsp->peercert = X509_dup(cert); | |
317 | /* NB we do not bother setting peerdn */ | |
318 | if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth)))) | |
319 | { | |
320 | log_write(0, LOG_MAIN, "[%s] %s verify denied by event-action: " | |
321 | "depth=%d cert=%s: %s", | |
322 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
323 | what, depth, dn, yield); | |
324 | *calledp = TRUE; | |
325 | if (!*optionalp) | |
326 | { | |
327 | if (old_cert) tlsp->peercert = old_cert; /* restore 1st failing cert */ | |
328 | return 1; /* reject (leaving peercert set) */ | |
329 | } | |
330 | DEBUG(D_tls) debug_printf("Event-action verify failure overridden " | |
331 | "(host in tls_try_verify_hosts)\n"); | |
332 | } | |
333 | X509_free(tlsp->peercert); | |
334 | tlsp->peercert = old_cert; | |
335 | } | |
336 | return 0; | |
337 | } | |
338 | #endif | |
339 | ||
059ec3d9 PH |
340 | /************************************************* |
341 | * Callback for verification * | |
342 | *************************************************/ | |
343 | ||
344 | /* The SSL library does certificate verification if set up to do so. This | |
345 | callback has the current yes/no state is in "state". If verification succeeded, | |
f69979cf JH |
346 | we set the certificate-verified flag. If verification failed, what happens |
347 | depends on whether the client is required to present a verifiable certificate | |
348 | or not. | |
059ec3d9 PH |
349 | |
350 | If verification is optional, we change the state to yes, but still log the | |
351 | verification error. For some reason (it really would help to have proper | |
352 | documentation of OpenSSL), this callback function then gets called again, this | |
f69979cf JH |
353 | time with state = 1. We must take care not to set the private verified flag on |
354 | the second time through. | |
059ec3d9 PH |
355 | |
356 | Note: this function is not called if the client fails to present a certificate | |
357 | when asked. We get here only if a certificate has been received. Handling of | |
358 | optional verification for this case is done when requesting SSL to verify, by | |
359 | setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case. | |
360 | ||
a7538db1 JH |
361 | May be called multiple times for different issues with a certificate, even |
362 | for a given "depth" in the certificate chain. | |
363 | ||
059ec3d9 | 364 | Arguments: |
f2f2c91b JH |
365 | preverify_ok current yes/no state as 1/0 |
366 | x509ctx certificate information. | |
367 | tlsp per-direction (client vs. server) support data | |
368 | calledp has-been-called flag | |
369 | optionalp verification-is-optional flag | |
059ec3d9 | 370 | |
f2f2c91b | 371 | Returns: 0 if verification should fail, otherwise 1 |
059ec3d9 PH |
372 | */ |
373 | ||
374 | static int | |
f2f2c91b | 375 | verify_callback(int preverify_ok, X509_STORE_CTX *x509ctx, |
421aff85 | 376 | tls_support *tlsp, BOOL *calledp, BOOL *optionalp) |
059ec3d9 | 377 | { |
421aff85 | 378 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); |
a7538db1 | 379 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
f69979cf | 380 | uschar dn[256]; |
059ec3d9 | 381 | |
f69979cf JH |
382 | X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)); |
383 | dn[sizeof(dn)-1] = '\0'; | |
059ec3d9 | 384 | |
f2f2c91b | 385 | if (preverify_ok == 0) |
059ec3d9 | 386 | { |
4c01d6ab JH |
387 | log_write(0, LOG_MAIN, "[%s] SSL verify error: depth=%d error=%s cert=%s", |
388 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
a7538db1 | 389 | depth, |
421aff85 | 390 | X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), |
f69979cf | 391 | dn); |
a2ff477a | 392 | *calledp = TRUE; |
9d1c15ef JH |
393 | if (!*optionalp) |
394 | { | |
f69979cf JH |
395 | if (!tlsp->peercert) |
396 | tlsp->peercert = X509_dup(cert); /* record failing cert */ | |
397 | return 0; /* reject */ | |
9d1c15ef | 398 | } |
059ec3d9 PH |
399 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
400 | "tls_try_verify_hosts)\n"); | |
059ec3d9 PH |
401 | } |
402 | ||
a7538db1 | 403 | else if (depth != 0) |
059ec3d9 | 404 | { |
f69979cf | 405 | DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, dn); |
f2de3a33 | 406 | #ifndef DISABLE_OCSP |
f5d78688 JH |
407 | if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store) |
408 | { /* client, wanting stapling */ | |
409 | /* Add the server cert's signing chain as the one | |
410 | for the verification of the OCSP stapled information. */ | |
94431adb | 411 | |
f5d78688 | 412 | if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, |
421aff85 | 413 | cert)) |
f5d78688 | 414 | ERR_clear_error(); |
c3033f13 | 415 | sk_X509_push(client_static_cbinfo->verify_stack, cert); |
f5d78688 | 416 | } |
a7538db1 | 417 | #endif |
0cbf2b82 | 418 | #ifndef DISABLE_EVENT |
f69979cf JH |
419 | if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) |
420 | return 0; /* reject, with peercert set */ | |
f5d78688 | 421 | #endif |
059ec3d9 PH |
422 | } |
423 | else | |
424 | { | |
55414b25 | 425 | const uschar * verify_cert_hostnames; |
e51c7be2 | 426 | |
e51c7be2 JH |
427 | if ( tlsp == &tls_out |
428 | && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames))) | |
429 | /* client, wanting hostname check */ | |
e51c7be2 | 430 | { |
f69979cf | 431 | |
740f36d4 | 432 | #ifdef EXIM_HAVE_OPENSSL_CHECKHOST |
f69979cf JH |
433 | # ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
434 | # define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0 | |
435 | # endif | |
436 | # ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS | |
437 | # define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0 | |
438 | # endif | |
e51c7be2 | 439 | int sep = 0; |
55414b25 | 440 | const uschar * list = verify_cert_hostnames; |
e51c7be2 | 441 | uschar * name; |
d8e7834a JH |
442 | int rc; |
443 | while ((name = string_nextinlist(&list, &sep, NULL, 0))) | |
f40d5be3 | 444 | if ((rc = X509_check_host(cert, CCS name, 0, |
8d692470 | 445 | X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
740f36d4 JH |
446 | | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS, |
447 | NULL))) | |
d8e7834a JH |
448 | { |
449 | if (rc < 0) | |
450 | { | |
93a6fce2 | 451 | log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", |
8cfd0f7b | 452 | deliver_host_address); |
d8e7834a JH |
453 | name = NULL; |
454 | } | |
e51c7be2 | 455 | break; |
d8e7834a | 456 | } |
e51c7be2 | 457 | if (!name) |
f69979cf | 458 | #else |
e51c7be2 | 459 | if (!tls_is_name_for_cert(verify_cert_hostnames, cert)) |
f69979cf | 460 | #endif |
e51c7be2 JH |
461 | { |
462 | log_write(0, LOG_MAIN, | |
b999c483 JH |
463 | "[%s] SSL verify error: certificate name mismatch: " |
464 | "DN=\"%s\" H=\"%s\"", | |
465 | deliver_host_address, dn, verify_cert_hostnames); | |
a3ef7310 JH |
466 | *calledp = TRUE; |
467 | if (!*optionalp) | |
f69979cf JH |
468 | { |
469 | if (!tlsp->peercert) | |
470 | tlsp->peercert = X509_dup(cert); /* record failing cert */ | |
471 | return 0; /* reject */ | |
472 | } | |
a3ef7310 JH |
473 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
474 | "tls_try_verify_hosts)\n"); | |
e51c7be2 | 475 | } |
f69979cf | 476 | } |
e51c7be2 | 477 | |
0cbf2b82 | 478 | #ifndef DISABLE_EVENT |
f69979cf JH |
479 | if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) |
480 | return 0; /* reject, with peercert set */ | |
e51c7be2 JH |
481 | #endif |
482 | ||
93dcb1c2 | 483 | DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n", |
f69979cf | 484 | *calledp ? "" : " authenticated", dn); |
93dcb1c2 JH |
485 | if (!*calledp) tlsp->certificate_verified = TRUE; |
486 | *calledp = TRUE; | |
059ec3d9 PH |
487 | } |
488 | ||
a7538db1 | 489 | return 1; /* accept, at least for this level */ |
059ec3d9 PH |
490 | } |
491 | ||
a2ff477a | 492 | static int |
f2f2c91b | 493 | verify_callback_client(int preverify_ok, X509_STORE_CTX *x509ctx) |
a2ff477a | 494 | { |
f2f2c91b JH |
495 | return verify_callback(preverify_ok, x509ctx, &tls_out, |
496 | &client_verify_callback_called, &client_verify_optional); | |
a2ff477a JH |
497 | } |
498 | ||
499 | static int | |
f2f2c91b | 500 | verify_callback_server(int preverify_ok, X509_STORE_CTX *x509ctx) |
a2ff477a | 501 | { |
f2f2c91b JH |
502 | return verify_callback(preverify_ok, x509ctx, &tls_in, |
503 | &server_verify_callback_called, &server_verify_optional); | |
a2ff477a JH |
504 | } |
505 | ||
059ec3d9 | 506 | |
e5cccda9 | 507 | #ifdef EXPERIMENTAL_DANE |
53a7196b | 508 | |
e5cccda9 JH |
509 | /* This gets called *by* the dane library verify callback, which interposes |
510 | itself. | |
511 | */ | |
512 | static int | |
f2f2c91b | 513 | verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx) |
e5cccda9 JH |
514 | { |
515 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); | |
f69979cf | 516 | uschar dn[256]; |
83b27293 | 517 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
5c75db2e | 518 | #ifndef DISABLE_EVENT |
f69979cf | 519 | BOOL dummy_called, optional = FALSE; |
83b27293 | 520 | #endif |
e5cccda9 | 521 | |
f69979cf JH |
522 | X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)); |
523 | dn[sizeof(dn)-1] = '\0'; | |
e5cccda9 | 524 | |
f2f2c91b JH |
525 | DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n", |
526 | preverify_ok ? "ok":"BAD", depth, dn); | |
e5cccda9 | 527 | |
0cbf2b82 | 528 | #ifndef DISABLE_EVENT |
f69979cf JH |
529 | if (verify_event(&tls_out, cert, depth, dn, |
530 | &dummy_called, &optional, US"DANE")) | |
531 | return 0; /* reject, with peercert set */ | |
83b27293 JH |
532 | #endif |
533 | ||
f2f2c91b | 534 | if (preverify_ok == 1) |
53a7196b | 535 | tls_out.dane_verified = |
e5cccda9 | 536 | tls_out.certificate_verified = TRUE; |
f2f2c91b JH |
537 | else |
538 | { | |
539 | int err = X509_STORE_CTX_get_error(x509ctx); | |
540 | DEBUG(D_tls) | |
541 | debug_printf(" - err %d '%s'\n", err, X509_verify_cert_error_string(err)); | |
3c51463e | 542 | if (err == X509_V_ERR_APPLICATION_VERIFICATION) |
f2f2c91b JH |
543 | preverify_ok = 1; |
544 | } | |
545 | return preverify_ok; | |
e5cccda9 | 546 | } |
53a7196b JH |
547 | |
548 | #endif /*EXPERIMENTAL_DANE*/ | |
e5cccda9 | 549 | |
059ec3d9 PH |
550 | |
551 | /************************************************* | |
552 | * Information callback * | |
553 | *************************************************/ | |
554 | ||
555 | /* The SSL library functions call this from time to time to indicate what they | |
7be682ca PP |
556 | are doing. We copy the string to the debugging output when TLS debugging has |
557 | been requested. | |
059ec3d9 PH |
558 | |
559 | Arguments: | |
560 | s the SSL connection | |
561 | where | |
562 | ret | |
563 | ||
564 | Returns: nothing | |
565 | */ | |
566 | ||
567 | static void | |
568 | info_callback(SSL *s, int where, int ret) | |
569 | { | |
570 | where = where; | |
571 | ret = ret; | |
572 | DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s)); | |
573 | } | |
574 | ||
575 | ||
576 | ||
577 | /************************************************* | |
578 | * Initialize for DH * | |
579 | *************************************************/ | |
580 | ||
581 | /* If dhparam is set, expand it, and load up the parameters for DH encryption. | |
582 | ||
583 | Arguments: | |
038597d2 | 584 | sctx The current SSL CTX (inbound or outbound) |
a799883d | 585 | dhparam DH parameter file or fixed parameter identity string |
7199e1ee | 586 | host connected host, if client; NULL if server |
cf0c6164 | 587 | errstr error string pointer |
059ec3d9 PH |
588 | |
589 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
590 | */ | |
591 | ||
592 | static BOOL | |
cf0c6164 | 593 | init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host, uschar ** errstr) |
059ec3d9 | 594 | { |
059ec3d9 PH |
595 | BIO *bio; |
596 | DH *dh; | |
597 | uschar *dhexpanded; | |
a799883d | 598 | const char *pem; |
6600985a | 599 | int dh_bitsize; |
059ec3d9 | 600 | |
cf0c6164 | 601 | if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded, errstr)) |
059ec3d9 PH |
602 | return FALSE; |
603 | ||
0df4ab80 | 604 | if (!dhexpanded || !*dhexpanded) |
a799883d | 605 | bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1); |
a799883d | 606 | else if (dhexpanded[0] == '/') |
059ec3d9 | 607 | { |
0df4ab80 | 608 | if (!(bio = BIO_new_file(CS dhexpanded, "r"))) |
059ec3d9 | 609 | { |
7199e1ee | 610 | tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), |
cf0c6164 | 611 | host, US strerror(errno), errstr); |
a799883d | 612 | return FALSE; |
059ec3d9 | 613 | } |
a799883d PP |
614 | } |
615 | else | |
616 | { | |
617 | if (Ustrcmp(dhexpanded, "none") == 0) | |
059ec3d9 | 618 | { |
a799883d PP |
619 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); |
620 | return TRUE; | |
059ec3d9 | 621 | } |
a799883d | 622 | |
0df4ab80 | 623 | if (!(pem = std_dh_prime_named(dhexpanded))) |
a799883d PP |
624 | { |
625 | tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded), | |
cf0c6164 | 626 | host, US strerror(errno), errstr); |
a799883d PP |
627 | return FALSE; |
628 | } | |
629 | bio = BIO_new_mem_buf(CS pem, -1); | |
630 | } | |
631 | ||
0df4ab80 | 632 | if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL))) |
a799883d | 633 | { |
059ec3d9 | 634 | BIO_free(bio); |
a799883d | 635 | tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded), |
cf0c6164 | 636 | host, NULL, errstr); |
a799883d PP |
637 | return FALSE; |
638 | } | |
639 | ||
6600985a PP |
640 | /* note: our default limit of 2236 is not a multiple of 8; the limit comes from |
641 | * an NSS limit, and the GnuTLS APIs handle bit-sizes fine, so we went with | |
642 | * 2236. But older OpenSSL can only report in bytes (octets), not bits. | |
643 | * If someone wants to dance at the edge, then they can raise the limit or use | |
644 | * current libraries. */ | |
645 | #ifdef EXIM_HAVE_OPENSSL_DH_BITS | |
646 | /* Added in commit 26c79d5641d; `git describe --contains` says OpenSSL_1_1_0-pre1~1022 | |
647 | * This predates OpenSSL_1_1_0 (before a, b, ...) so is in all 1.1.0 */ | |
648 | dh_bitsize = DH_bits(dh); | |
649 | #else | |
650 | dh_bitsize = 8 * DH_size(dh); | |
651 | #endif | |
652 | ||
a799883d PP |
653 | /* Even if it is larger, we silently return success rather than cause things |
654 | * to fail out, so that a too-large DH will not knock out all TLS; it's a | |
655 | * debatable choice. */ | |
6600985a | 656 | if (dh_bitsize > tls_dh_max_bits) |
a799883d PP |
657 | { |
658 | DEBUG(D_tls) | |
170f4904 | 659 | debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d\n", |
6600985a | 660 | dh_bitsize, tls_dh_max_bits); |
a799883d PP |
661 | } |
662 | else | |
663 | { | |
664 | SSL_CTX_set_tmp_dh(sctx, dh); | |
665 | DEBUG(D_tls) | |
666 | debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n", | |
6600985a | 667 | dhexpanded ? dhexpanded : US"default", dh_bitsize); |
059ec3d9 PH |
668 | } |
669 | ||
a799883d PP |
670 | DH_free(dh); |
671 | BIO_free(bio); | |
672 | ||
673 | return TRUE; | |
059ec3d9 PH |
674 | } |
675 | ||
676 | ||
677 | ||
678 | ||
038597d2 PP |
679 | /************************************************* |
680 | * Initialize for ECDH * | |
681 | *************************************************/ | |
682 | ||
683 | /* Load parameters for ECDH encryption. | |
684 | ||
685 | For now, we stick to NIST P-256 because: it's simple and easy to configure; | |
686 | it avoids any patent issues that might bite redistributors; despite events in | |
687 | the news and concerns over curve choices, we're not cryptographers, we're not | |
688 | pretending to be, and this is "good enough" to be better than no support, | |
689 | protecting against most adversaries. Given another year or two, there might | |
690 | be sufficient clarity about a "right" way forward to let us make an informed | |
691 | decision, instead of a knee-jerk reaction. | |
692 | ||
693 | Longer-term, we should look at supporting both various named curves and | |
694 | external files generated with "openssl ecparam", much as we do for init_dh(). | |
695 | We should also support "none" as a value, to explicitly avoid initialisation. | |
696 | ||
697 | Patches welcome. | |
698 | ||
699 | Arguments: | |
700 | sctx The current SSL CTX (inbound or outbound) | |
701 | host connected host, if client; NULL if server | |
cf0c6164 | 702 | errstr error string pointer |
038597d2 PP |
703 | |
704 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
705 | */ | |
706 | ||
707 | static BOOL | |
cf0c6164 | 708 | init_ecdh(SSL_CTX * sctx, host_item * host, uschar ** errstr) |
038597d2 | 709 | { |
63f0dbe0 JH |
710 | #ifdef OPENSSL_NO_ECDH |
711 | return TRUE; | |
712 | #else | |
713 | ||
10ca4f1c JH |
714 | EC_KEY * ecdh; |
715 | uschar * exp_curve; | |
716 | int nid; | |
717 | BOOL rv; | |
718 | ||
038597d2 PP |
719 | if (host) /* No ECDH setup for clients, only for servers */ |
720 | return TRUE; | |
721 | ||
10ca4f1c | 722 | # ifndef EXIM_HAVE_ECDH |
038597d2 PP |
723 | DEBUG(D_tls) |
724 | debug_printf("No OpenSSL API to define ECDH parameters, skipping\n"); | |
725 | return TRUE; | |
038597d2 | 726 | # else |
10ca4f1c | 727 | |
cf0c6164 | 728 | if (!expand_check(tls_eccurve, US"tls_eccurve", &exp_curve, errstr)) |
10ca4f1c JH |
729 | return FALSE; |
730 | if (!exp_curve || !*exp_curve) | |
731 | return TRUE; | |
732 | ||
8e53a4fc | 733 | /* "auto" needs to be handled carefully. |
4c04137d | 734 | * OpenSSL < 1.0.2: we do not select anything, but fallback to prime256v1 |
8e53a4fc | 735 | * OpenSSL < 1.1.0: we have to call SSL_CTX_set_ecdh_auto |
4c04137d | 736 | * (openssl/ssl.h defines SSL_CTRL_SET_ECDH_AUTO) |
8e53a4fc HSHR |
737 | * OpenSSL >= 1.1.0: we do not set anything, the libray does autoselection |
738 | * https://github.com/openssl/openssl/commit/fe6ef2472db933f01b59cad82aa925736935984b | |
739 | */ | |
10ca4f1c | 740 | if (Ustrcmp(exp_curve, "auto") == 0) |
038597d2 | 741 | { |
8e53a4fc | 742 | #if OPENSSL_VERSION_NUMBER < 0x10002000L |
10ca4f1c | 743 | DEBUG(D_tls) debug_printf( |
8e53a4fc | 744 | "ECDH OpenSSL < 1.0.2: temp key parameter settings: overriding \"auto\" with \"prime256v1\"\n"); |
78a3bbd5 | 745 | exp_curve = US"prime256v1"; |
8e53a4fc HSHR |
746 | #else |
747 | # if defined SSL_CTRL_SET_ECDH_AUTO | |
748 | DEBUG(D_tls) debug_printf( | |
749 | "ECDH OpenSSL 1.0.2+ temp key parameter settings: autoselection\n"); | |
10ca4f1c JH |
750 | SSL_CTX_set_ecdh_auto(sctx, 1); |
751 | return TRUE; | |
8e53a4fc HSHR |
752 | # else |
753 | DEBUG(D_tls) debug_printf( | |
754 | "ECDH OpenSSL 1.1.0+ temp key parameter settings: default selection\n"); | |
755 | return TRUE; | |
756 | # endif | |
757 | #endif | |
10ca4f1c | 758 | } |
038597d2 | 759 | |
10ca4f1c JH |
760 | DEBUG(D_tls) debug_printf("ECDH: curve '%s'\n", exp_curve); |
761 | if ( (nid = OBJ_sn2nid (CCS exp_curve)) == NID_undef | |
762 | # ifdef EXIM_HAVE_OPENSSL_EC_NIST2NID | |
763 | && (nid = EC_curve_nist2nid(CCS exp_curve)) == NID_undef | |
764 | # endif | |
765 | ) | |
766 | { | |
cf0c6164 JH |
767 | tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", exp_curve), |
768 | host, NULL, errstr); | |
10ca4f1c JH |
769 | return FALSE; |
770 | } | |
038597d2 | 771 | |
10ca4f1c JH |
772 | if (!(ecdh = EC_KEY_new_by_curve_name(nid))) |
773 | { | |
cf0c6164 | 774 | tls_error(US"Unable to create ec curve", host, NULL, errstr); |
10ca4f1c | 775 | return FALSE; |
038597d2 | 776 | } |
10ca4f1c JH |
777 | |
778 | /* The "tmp" in the name here refers to setting a temporary key | |
779 | not to the stability of the interface. */ | |
780 | ||
781 | if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0)) | |
cf0c6164 | 782 | tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), host, NULL, errstr); |
10ca4f1c JH |
783 | else |
784 | DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve); | |
785 | ||
786 | EC_KEY_free(ecdh); | |
787 | return !rv; | |
788 | ||
789 | # endif /*EXIM_HAVE_ECDH*/ | |
790 | #endif /*OPENSSL_NO_ECDH*/ | |
038597d2 PP |
791 | } |
792 | ||
793 | ||
794 | ||
795 | ||
f2de3a33 | 796 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
797 | /************************************************* |
798 | * Load OCSP information into state * | |
799 | *************************************************/ | |
f5d78688 | 800 | /* Called to load the server OCSP response from the given file into memory, once |
3f7eeb86 PP |
801 | caller has determined this is needed. Checks validity. Debugs a message |
802 | if invalid. | |
803 | ||
804 | ASSUMES: single response, for single cert. | |
805 | ||
806 | Arguments: | |
807 | sctx the SSL_CTX* to update | |
808 | cbinfo various parts of session state | |
809 | expanded the filename putatively holding an OCSP response | |
810 | ||
811 | */ | |
812 | ||
813 | static void | |
f5d78688 | 814 | ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded) |
3f7eeb86 | 815 | { |
ee5b1e28 JH |
816 | BIO * bio; |
817 | OCSP_RESPONSE * resp; | |
818 | OCSP_BASICRESP * basic_response; | |
819 | OCSP_SINGLERESP * single_response; | |
820 | ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd; | |
ee5b1e28 | 821 | STACK_OF(X509) * sk; |
3f7eeb86 PP |
822 | unsigned long verify_flags; |
823 | int status, reason, i; | |
824 | ||
f5d78688 JH |
825 | cbinfo->u_ocsp.server.file_expanded = string_copy(expanded); |
826 | if (cbinfo->u_ocsp.server.response) | |
3f7eeb86 | 827 | { |
f5d78688 JH |
828 | OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response); |
829 | cbinfo->u_ocsp.server.response = NULL; | |
3f7eeb86 PP |
830 | } |
831 | ||
ee5b1e28 | 832 | if (!(bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb"))) |
3f7eeb86 PP |
833 | { |
834 | DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", | |
f5d78688 | 835 | cbinfo->u_ocsp.server.file_expanded); |
3f7eeb86 PP |
836 | return; |
837 | } | |
838 | ||
839 | resp = d2i_OCSP_RESPONSE_bio(bio, NULL); | |
840 | BIO_free(bio); | |
841 | if (!resp) | |
842 | { | |
843 | DEBUG(D_tls) debug_printf("Error reading OCSP response.\n"); | |
844 | return; | |
845 | } | |
846 | ||
ee5b1e28 | 847 | if ((status = OCSP_response_status(resp)) != OCSP_RESPONSE_STATUS_SUCCESSFUL) |
3f7eeb86 PP |
848 | { |
849 | DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", | |
850 | OCSP_response_status_str(status), status); | |
f5d78688 | 851 | goto bad; |
3f7eeb86 PP |
852 | } |
853 | ||
ee5b1e28 | 854 | if (!(basic_response = OCSP_response_get1_basic(resp))) |
3f7eeb86 PP |
855 | { |
856 | DEBUG(D_tls) | |
857 | debug_printf("OCSP response parse error: unable to extract basic response.\n"); | |
f5d78688 | 858 | goto bad; |
3f7eeb86 PP |
859 | } |
860 | ||
c3033f13 | 861 | sk = cbinfo->verify_stack; |
3f7eeb86 PP |
862 | verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ |
863 | ||
864 | /* May need to expose ability to adjust those flags? | |
865 | OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT | |
866 | OCSP_TRUSTOTHER OCSP_NOINTERN */ | |
867 | ||
4c04137d | 868 | /* This does a full verify on the OCSP proof before we load it for serving |
ee5b1e28 JH |
869 | up; possibly overkill - just date-checks might be nice enough. |
870 | ||
871 | OCSP_basic_verify takes a "store" arg, but does not | |
872 | use it for the chain verification, which is all we do | |
873 | when OCSP_NOVERIFY is set. The content from the wire | |
874 | "basic_response" and a cert-stack "sk" are all that is used. | |
875 | ||
c3033f13 JH |
876 | We have a stack, loaded in setup_certs() if tls_verify_certificates |
877 | was a file (not a directory, or "system"). It is unfortunate we | |
878 | cannot used the connection context store, as that would neatly | |
879 | handle the "system" case too, but there seems to be no library | |
880 | function for getting a stack from a store. | |
e3555426 | 881 | [ In OpenSSL 1.1 - ? X509_STORE_CTX_get0_chain(ctx) ? ] |
c3033f13 JH |
882 | We do not free the stack since it could be needed a second time for |
883 | SNI handling. | |
884 | ||
4c04137d | 885 | Separately we might try to replace using OCSP_basic_verify() - which seems to not |
ee5b1e28 JH |
886 | be a public interface into the OpenSSL library (there's no manual entry) - |
887 | But what with? We also use OCSP_basic_verify in the client stapling callback. | |
4c04137d | 888 | And there we NEED it; we must verify that status... unless the |
ee5b1e28 JH |
889 | library does it for us anyway? */ |
890 | ||
891 | if ((i = OCSP_basic_verify(basic_response, sk, NULL, verify_flags)) < 0) | |
3f7eeb86 | 892 | { |
ee5b1e28 JH |
893 | DEBUG(D_tls) |
894 | { | |
3f7eeb86 PP |
895 | ERR_error_string(ERR_get_error(), ssl_errstring); |
896 | debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); | |
f5d78688 JH |
897 | } |
898 | goto bad; | |
3f7eeb86 PP |
899 | } |
900 | ||
901 | /* Here's the simplifying assumption: there's only one response, for the | |
902 | one certificate we use, and nothing for anything else in a chain. If this | |
903 | proves false, we need to extract a cert id from our issued cert | |
904 | (tls_certificate) and use that for OCSP_resp_find_status() (which finds the | |
905 | right cert in the stack and then calls OCSP_single_get0_status()). | |
906 | ||
907 | I'm hoping to avoid reworking a bunch more of how we handle state here. */ | |
ee5b1e28 JH |
908 | |
909 | if (!(single_response = OCSP_resp_get0(basic_response, 0))) | |
3f7eeb86 PP |
910 | { |
911 | DEBUG(D_tls) | |
912 | debug_printf("Unable to get first response from OCSP basic response.\n"); | |
f5d78688 | 913 | goto bad; |
3f7eeb86 PP |
914 | } |
915 | ||
916 | status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd); | |
f5d78688 | 917 | if (status != V_OCSP_CERTSTATUS_GOOD) |
3f7eeb86 | 918 | { |
f5d78688 JH |
919 | DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n", |
920 | OCSP_cert_status_str(status), status, | |
921 | OCSP_crl_reason_str(reason), reason); | |
922 | goto bad; | |
3f7eeb86 PP |
923 | } |
924 | ||
925 | if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
926 | { | |
927 | DEBUG(D_tls) debug_printf("OCSP status invalid times.\n"); | |
f5d78688 | 928 | goto bad; |
3f7eeb86 PP |
929 | } |
930 | ||
f5d78688 | 931 | supply_response: |
018058b2 | 932 | cbinfo->u_ocsp.server.response = resp; |
f5d78688 JH |
933 | return; |
934 | ||
935 | bad: | |
018058b2 JH |
936 | if (running_in_test_harness) |
937 | { | |
938 | extern char ** environ; | |
939 | uschar ** p; | |
bc3c7bb7 | 940 | if (environ) for (p = USS environ; *p != NULL; p++) |
018058b2 JH |
941 | if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) |
942 | { | |
943 | DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n"); | |
944 | goto supply_response; | |
945 | } | |
946 | } | |
f5d78688 | 947 | return; |
3f7eeb86 | 948 | } |
f2de3a33 | 949 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
950 | |
951 | ||
952 | ||
953 | ||
23bb6982 JH |
954 | /* Create and install a selfsigned certificate, for use in server mode */ |
955 | ||
956 | static int | |
cf0c6164 | 957 | tls_install_selfsign(SSL_CTX * sctx, uschar ** errstr) |
23bb6982 JH |
958 | { |
959 | X509 * x509 = NULL; | |
960 | EVP_PKEY * pkey; | |
961 | RSA * rsa; | |
962 | X509_NAME * name; | |
963 | uschar * where; | |
964 | ||
965 | where = US"allocating pkey"; | |
966 | if (!(pkey = EVP_PKEY_new())) | |
967 | goto err; | |
968 | ||
969 | where = US"allocating cert"; | |
970 | if (!(x509 = X509_new())) | |
971 | goto err; | |
972 | ||
973 | where = US"generating pkey"; | |
974 | /* deprecated, use RSA_generate_key_ex() */ | |
975 | if (!(rsa = RSA_generate_key(1024, RSA_F4, NULL, NULL))) | |
976 | goto err; | |
977 | ||
4c04137d | 978 | where = US"assigning pkey"; |
23bb6982 JH |
979 | if (!EVP_PKEY_assign_RSA(pkey, rsa)) |
980 | goto err; | |
981 | ||
982 | X509_set_version(x509, 2); /* N+1 - version 3 */ | |
983 | ASN1_INTEGER_set(X509_get_serialNumber(x509), 0); | |
984 | X509_gmtime_adj(X509_get_notBefore(x509), 0); | |
985 | X509_gmtime_adj(X509_get_notAfter(x509), (long)60 * 60); /* 1 hour */ | |
986 | X509_set_pubkey(x509, pkey); | |
987 | ||
988 | name = X509_get_subject_name(x509); | |
989 | X509_NAME_add_entry_by_txt(name, "C", | |
4dc2379a | 990 | MBSTRING_ASC, CUS "UK", -1, -1, 0); |
23bb6982 | 991 | X509_NAME_add_entry_by_txt(name, "O", |
4dc2379a | 992 | MBSTRING_ASC, CUS "Exim Developers", -1, -1, 0); |
23bb6982 | 993 | X509_NAME_add_entry_by_txt(name, "CN", |
4dc2379a | 994 | MBSTRING_ASC, CUS smtp_active_hostname, -1, -1, 0); |
23bb6982 JH |
995 | X509_set_issuer_name(x509, name); |
996 | ||
997 | where = US"signing cert"; | |
998 | if (!X509_sign(x509, pkey, EVP_md5())) | |
999 | goto err; | |
1000 | ||
1001 | where = US"installing selfsign cert"; | |
1002 | if (!SSL_CTX_use_certificate(sctx, x509)) | |
1003 | goto err; | |
1004 | ||
1005 | where = US"installing selfsign key"; | |
1006 | if (!SSL_CTX_use_PrivateKey(sctx, pkey)) | |
1007 | goto err; | |
1008 | ||
1009 | return OK; | |
1010 | ||
1011 | err: | |
cf0c6164 | 1012 | (void) tls_error(where, NULL, NULL, errstr); |
23bb6982 JH |
1013 | if (x509) X509_free(x509); |
1014 | if (pkey) EVP_PKEY_free(pkey); | |
1015 | return DEFER; | |
1016 | } | |
1017 | ||
1018 | ||
1019 | ||
1020 | ||
7be682ca PP |
1021 | /************************************************* |
1022 | * Expand key and cert file specs * | |
1023 | *************************************************/ | |
1024 | ||
f5d78688 | 1025 | /* Called once during tls_init and possibly again during TLS setup, for a |
7be682ca PP |
1026 | new context, if Server Name Indication was used and tls_sni was seen in |
1027 | the certificate string. | |
1028 | ||
1029 | Arguments: | |
1030 | sctx the SSL_CTX* to update | |
1031 | cbinfo various parts of session state | |
cf0c6164 | 1032 | errstr error string pointer |
7be682ca PP |
1033 | |
1034 | Returns: OK/DEFER/FAIL | |
1035 | */ | |
1036 | ||
1037 | static int | |
cf0c6164 JH |
1038 | tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, |
1039 | uschar ** errstr) | |
7be682ca PP |
1040 | { |
1041 | uschar *expanded; | |
1042 | ||
23bb6982 | 1043 | if (!cbinfo->certificate) |
7be682ca | 1044 | { |
23bb6982 JH |
1045 | if (cbinfo->host) /* client */ |
1046 | return OK; | |
1047 | /* server */ | |
cf0c6164 | 1048 | if (tls_install_selfsign(sctx, errstr) != OK) |
23bb6982 | 1049 | return DEFER; |
7be682ca | 1050 | } |
23bb6982 JH |
1051 | else |
1052 | { | |
1053 | if (Ustrstr(cbinfo->certificate, US"tls_sni") || | |
1054 | Ustrstr(cbinfo->certificate, US"tls_in_sni") || | |
1055 | Ustrstr(cbinfo->certificate, US"tls_out_sni") | |
1056 | ) | |
1057 | reexpand_tls_files_for_sni = TRUE; | |
7be682ca | 1058 | |
cf0c6164 | 1059 | if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded, errstr)) |
23bb6982 JH |
1060 | return DEFER; |
1061 | ||
1062 | if (expanded != NULL) | |
1063 | { | |
1064 | DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); | |
1065 | if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded)) | |
1066 | return tls_error(string_sprintf( | |
1067 | "SSL_CTX_use_certificate_chain_file file=%s", expanded), | |
cf0c6164 | 1068 | cbinfo->host, NULL, errstr); |
23bb6982 | 1069 | } |
7be682ca | 1070 | |
23bb6982 | 1071 | if (cbinfo->privatekey != NULL && |
cf0c6164 | 1072 | !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded, errstr)) |
23bb6982 | 1073 | return DEFER; |
7be682ca | 1074 | |
23bb6982 JH |
1075 | /* If expansion was forced to fail, key_expanded will be NULL. If the result |
1076 | of the expansion is an empty string, ignore it also, and assume the private | |
1077 | key is in the same file as the certificate. */ | |
1078 | ||
1079 | if (expanded && *expanded) | |
1080 | { | |
1081 | DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); | |
1082 | if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM)) | |
1083 | return tls_error(string_sprintf( | |
cf0c6164 | 1084 | "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL, errstr); |
23bb6982 | 1085 | } |
7be682ca PP |
1086 | } |
1087 | ||
f2de3a33 | 1088 | #ifndef DISABLE_OCSP |
f40d5be3 | 1089 | if (cbinfo->is_server && cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1090 | { |
cf0c6164 | 1091 | if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded, errstr)) |
3f7eeb86 PP |
1092 | return DEFER; |
1093 | ||
f40d5be3 | 1094 | if (expanded && *expanded) |
3f7eeb86 PP |
1095 | { |
1096 | DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded); | |
f40d5be3 JH |
1097 | if ( cbinfo->u_ocsp.server.file_expanded |
1098 | && (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0)) | |
3f7eeb86 | 1099 | { |
f40d5be3 JH |
1100 | DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n"); |
1101 | } | |
1102 | else | |
f40d5be3 | 1103 | ocsp_load_response(sctx, cbinfo, expanded); |
3f7eeb86 PP |
1104 | } |
1105 | } | |
1106 | #endif | |
1107 | ||
7be682ca PP |
1108 | return OK; |
1109 | } | |
1110 | ||
1111 | ||
1112 | ||
1113 | ||
1114 | /************************************************* | |
1115 | * Callback to handle SNI * | |
1116 | *************************************************/ | |
1117 | ||
1118 | /* Called when acting as server during the TLS session setup if a Server Name | |
1119 | Indication extension was sent by the client. | |
1120 | ||
1121 | API documentation is OpenSSL s_server.c implementation. | |
1122 | ||
1123 | Arguments: | |
1124 | s SSL* of the current session | |
1125 | ad unknown (part of OpenSSL API) (unused) | |
1126 | arg Callback of "our" registered data | |
1127 | ||
1128 | Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK} | |
1129 | */ | |
1130 | ||
3bcbbbe2 | 1131 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
7be682ca PP |
1132 | static int |
1133 | tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg) | |
1134 | { | |
1135 | const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); | |
3f7eeb86 | 1136 | tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; |
7be682ca | 1137 | int rc; |
3f0945ff | 1138 | int old_pool = store_pool; |
cf0c6164 | 1139 | uschar * dummy_errstr; |
7be682ca PP |
1140 | |
1141 | if (!servername) | |
1142 | return SSL_TLSEXT_ERR_OK; | |
1143 | ||
3f0945ff | 1144 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername, |
7be682ca PP |
1145 | reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)"); |
1146 | ||
1147 | /* Make the extension value available for expansion */ | |
3f0945ff | 1148 | store_pool = POOL_PERM; |
817d9f57 | 1149 | tls_in.sni = string_copy(US servername); |
3f0945ff | 1150 | store_pool = old_pool; |
7be682ca PP |
1151 | |
1152 | if (!reexpand_tls_files_for_sni) | |
1153 | return SSL_TLSEXT_ERR_OK; | |
1154 | ||
1155 | /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually; | |
1156 | not confident that memcpy wouldn't break some internal reference counting. | |
1157 | Especially since there's a references struct member, which would be off. */ | |
1158 | ||
0df4ab80 | 1159 | if (!(server_sni = SSL_CTX_new(SSLv23_server_method()))) |
7be682ca PP |
1160 | { |
1161 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
1162 | DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring); | |
1163 | return SSL_TLSEXT_ERR_NOACK; | |
1164 | } | |
1165 | ||
1166 | /* Not sure how many of these are actually needed, since SSL object | |
1167 | already exists. Might even need this selfsame callback, for reneg? */ | |
1168 | ||
817d9f57 JH |
1169 | SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx)); |
1170 | SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx)); | |
1171 | SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); | |
1172 | SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); | |
1173 | SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); | |
1174 | SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); | |
038597d2 | 1175 | |
cf0c6164 JH |
1176 | if ( !init_dh(server_sni, cbinfo->dhparam, NULL, &dummy_errstr) |
1177 | || !init_ecdh(server_sni, NULL, &dummy_errstr) | |
038597d2 PP |
1178 | ) |
1179 | return SSL_TLSEXT_ERR_NOACK; | |
1180 | ||
7be682ca | 1181 | if (cbinfo->server_cipher_list) |
817d9f57 | 1182 | SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list); |
f2de3a33 | 1183 | #ifndef DISABLE_OCSP |
f5d78688 | 1184 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1185 | { |
f5d78688 | 1186 | SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb); |
14c7b357 | 1187 | SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo); |
3f7eeb86 PP |
1188 | } |
1189 | #endif | |
7be682ca | 1190 | |
c3033f13 | 1191 | if ((rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, |
cf0c6164 | 1192 | verify_callback_server, &dummy_errstr)) != OK) |
c3033f13 | 1193 | return SSL_TLSEXT_ERR_NOACK; |
7be682ca | 1194 | |
3f7eeb86 PP |
1195 | /* do this after setup_certs, because this can require the certs for verifying |
1196 | OCSP information. */ | |
cf0c6164 | 1197 | if ((rc = tls_expand_session_files(server_sni, cbinfo, &dummy_errstr)) != OK) |
0df4ab80 | 1198 | return SSL_TLSEXT_ERR_NOACK; |
a799883d | 1199 | |
7be682ca | 1200 | DEBUG(D_tls) debug_printf("Switching SSL context.\n"); |
817d9f57 | 1201 | SSL_set_SSL_CTX(s, server_sni); |
7be682ca PP |
1202 | |
1203 | return SSL_TLSEXT_ERR_OK; | |
1204 | } | |
3bcbbbe2 | 1205 | #endif /* EXIM_HAVE_OPENSSL_TLSEXT */ |
7be682ca PP |
1206 | |
1207 | ||
1208 | ||
1209 | ||
f2de3a33 | 1210 | #ifndef DISABLE_OCSP |
f5d78688 | 1211 | |
3f7eeb86 PP |
1212 | /************************************************* |
1213 | * Callback to handle OCSP Stapling * | |
1214 | *************************************************/ | |
1215 | ||
1216 | /* Called when acting as server during the TLS session setup if the client | |
1217 | requests OCSP information with a Certificate Status Request. | |
1218 | ||
1219 | Documentation via openssl s_server.c and the Apache patch from the OpenSSL | |
1220 | project. | |
1221 | ||
1222 | */ | |
1223 | ||
1224 | static int | |
f5d78688 | 1225 | tls_server_stapling_cb(SSL *s, void *arg) |
3f7eeb86 PP |
1226 | { |
1227 | const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; | |
1228 | uschar *response_der; | |
1229 | int response_der_len; | |
1230 | ||
af4a1bca | 1231 | DEBUG(D_tls) |
b3ef41c9 | 1232 | debug_printf("Received TLS status request (OCSP stapling); %s response\n", |
f5d78688 JH |
1233 | cbinfo->u_ocsp.server.response ? "have" : "lack"); |
1234 | ||
44662487 | 1235 | tls_in.ocsp = OCSP_NOT_RESP; |
f5d78688 | 1236 | if (!cbinfo->u_ocsp.server.response) |
3f7eeb86 PP |
1237 | return SSL_TLSEXT_ERR_NOACK; |
1238 | ||
1239 | response_der = NULL; | |
44662487 JH |
1240 | response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response, |
1241 | &response_der); | |
3f7eeb86 PP |
1242 | if (response_der_len <= 0) |
1243 | return SSL_TLSEXT_ERR_NOACK; | |
1244 | ||
5e55c7a9 | 1245 | SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len); |
44662487 | 1246 | tls_in.ocsp = OCSP_VFIED; |
3f7eeb86 PP |
1247 | return SSL_TLSEXT_ERR_OK; |
1248 | } | |
1249 | ||
3f7eeb86 | 1250 | |
f5d78688 JH |
1251 | static void |
1252 | time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time) | |
1253 | { | |
1254 | BIO_printf(bp, "\t%s: ", str); | |
1255 | ASN1_GENERALIZEDTIME_print(bp, time); | |
1256 | BIO_puts(bp, "\n"); | |
1257 | } | |
1258 | ||
1259 | static int | |
1260 | tls_client_stapling_cb(SSL *s, void *arg) | |
1261 | { | |
1262 | tls_ext_ctx_cb * cbinfo = arg; | |
1263 | const unsigned char * p; | |
1264 | int len; | |
1265 | OCSP_RESPONSE * rsp; | |
1266 | OCSP_BASICRESP * bs; | |
1267 | int i; | |
1268 | ||
1269 | DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):"); | |
1270 | len = SSL_get_tlsext_status_ocsp_resp(s, &p); | |
1271 | if(!p) | |
1272 | { | |
44662487 | 1273 | /* Expect this when we requested ocsp but got none */ |
6c6d6e48 | 1274 | if (cbinfo->u_ocsp.client.verify_required && LOGGING(tls_cipher)) |
44662487 | 1275 | log_write(0, LOG_MAIN, "Received TLS status callback, null content"); |
f5d78688 JH |
1276 | else |
1277 | DEBUG(D_tls) debug_printf(" null\n"); | |
44662487 | 1278 | return cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 1279 | } |
018058b2 | 1280 | |
f5d78688 JH |
1281 | if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) |
1282 | { | |
018058b2 | 1283 | tls_out.ocsp = OCSP_FAILED; |
6c6d6e48 | 1284 | if (LOGGING(tls_cipher)) |
1eca31ca | 1285 | log_write(0, LOG_MAIN, "Received TLS cert status response, parse error"); |
f5d78688 JH |
1286 | else |
1287 | DEBUG(D_tls) debug_printf(" parse error\n"); | |
1288 | return 0; | |
1289 | } | |
1290 | ||
1291 | if(!(bs = OCSP_response_get1_basic(rsp))) | |
1292 | { | |
018058b2 | 1293 | tls_out.ocsp = OCSP_FAILED; |
6c6d6e48 | 1294 | if (LOGGING(tls_cipher)) |
1eca31ca | 1295 | log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response"); |
f5d78688 JH |
1296 | else |
1297 | DEBUG(D_tls) debug_printf(" error parsing response\n"); | |
1298 | OCSP_RESPONSE_free(rsp); | |
1299 | return 0; | |
1300 | } | |
1301 | ||
1302 | /* We'd check the nonce here if we'd put one in the request. */ | |
1303 | /* However that would defeat cacheability on the server so we don't. */ | |
1304 | ||
f5d78688 JH |
1305 | /* This section of code reworked from OpenSSL apps source; |
1306 | The OpenSSL Project retains copyright: | |
1307 | Copyright (c) 1999 The OpenSSL Project. All rights reserved. | |
1308 | */ | |
1309 | { | |
1310 | BIO * bp = NULL; | |
f5d78688 JH |
1311 | int status, reason; |
1312 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
1313 | ||
1314 | DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE); | |
1315 | ||
1316 | /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */ | |
1317 | ||
1318 | /* Use the chain that verified the server cert to verify the stapled info */ | |
1319 | /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */ | |
1320 | ||
c3033f13 | 1321 | if ((i = OCSP_basic_verify(bs, cbinfo->verify_stack, |
44662487 | 1322 | cbinfo->u_ocsp.client.verify_store, 0)) <= 0) |
f5d78688 | 1323 | { |
018058b2 | 1324 | tls_out.ocsp = OCSP_FAILED; |
6c6d6e48 | 1325 | if (LOGGING(tls_cipher)) |
1eca31ca | 1326 | log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable"); |
f5d78688 JH |
1327 | BIO_printf(bp, "OCSP response verify failure\n"); |
1328 | ERR_print_errors(bp); | |
c8dfb21d | 1329 | goto failed; |
f5d78688 JH |
1330 | } |
1331 | ||
1332 | BIO_printf(bp, "OCSP response well-formed and signed OK\n"); | |
1333 | ||
c8dfb21d JH |
1334 | /*XXX So we have a good stapled OCSP status. How do we know |
1335 | it is for the cert of interest? OpenSSL 1.1.0 has a routine | |
1336 | OCSP_resp_find_status() which matches on a cert id, which presumably | |
1337 | we should use. Making an id needs OCSP_cert_id_new(), which takes | |
1338 | issuerName, issuerKey, serialNumber. Are they all in the cert? | |
1339 | ||
1340 | For now, carry on blindly accepting the resp. */ | |
1341 | ||
f5d78688 | 1342 | { |
f5d78688 JH |
1343 | OCSP_SINGLERESP * single; |
1344 | ||
c8dfb21d JH |
1345 | #ifdef EXIM_HAVE_OCSP_RESP_COUNT |
1346 | if (OCSP_resp_count(bs) != 1) | |
1347 | #else | |
1348 | STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; | |
f5d78688 | 1349 | if (sk_OCSP_SINGLERESP_num(sresp) != 1) |
c8dfb21d | 1350 | #endif |
f5d78688 | 1351 | { |
018058b2 | 1352 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1353 | log_write(0, LOG_MAIN, "OCSP stapling " |
1354 | "with multiple responses not handled"); | |
c8dfb21d | 1355 | goto failed; |
f5d78688 JH |
1356 | } |
1357 | single = OCSP_resp_get0(bs, 0); | |
44662487 JH |
1358 | status = OCSP_single_get0_status(single, &reason, &rev, |
1359 | &thisupd, &nextupd); | |
f5d78688 JH |
1360 | } |
1361 | ||
f5d78688 JH |
1362 | DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd); |
1363 | DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd); | |
44662487 JH |
1364 | if (!OCSP_check_validity(thisupd, nextupd, |
1365 | EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
f5d78688 | 1366 | { |
018058b2 | 1367 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
1368 | DEBUG(D_tls) ERR_print_errors(bp); |
1369 | log_write(0, LOG_MAIN, "Server OSCP dates invalid"); | |
f5d78688 | 1370 | } |
44662487 | 1371 | else |
f5d78688 | 1372 | { |
44662487 JH |
1373 | DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n", |
1374 | OCSP_cert_status_str(status)); | |
1375 | switch(status) | |
1376 | { | |
1377 | case V_OCSP_CERTSTATUS_GOOD: | |
44662487 | 1378 | tls_out.ocsp = OCSP_VFIED; |
018058b2 | 1379 | i = 1; |
c8dfb21d | 1380 | goto good; |
44662487 | 1381 | case V_OCSP_CERTSTATUS_REVOKED: |
018058b2 | 1382 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1383 | log_write(0, LOG_MAIN, "Server certificate revoked%s%s", |
1384 | reason != -1 ? "; reason: " : "", | |
1385 | reason != -1 ? OCSP_crl_reason_str(reason) : ""); | |
1386 | DEBUG(D_tls) time_print(bp, "Revocation Time", rev); | |
44662487 JH |
1387 | break; |
1388 | default: | |
018058b2 | 1389 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1390 | log_write(0, LOG_MAIN, |
1391 | "Server certificate status unknown, in OCSP stapling"); | |
44662487 JH |
1392 | break; |
1393 | } | |
f5d78688 | 1394 | } |
c8dfb21d JH |
1395 | failed: |
1396 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1397 | good: | |
f5d78688 JH |
1398 | BIO_free(bp); |
1399 | } | |
1400 | ||
1401 | OCSP_RESPONSE_free(rsp); | |
1402 | return i; | |
1403 | } | |
f2de3a33 | 1404 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
1405 | |
1406 | ||
059ec3d9 PH |
1407 | /************************************************* |
1408 | * Initialize for TLS * | |
1409 | *************************************************/ | |
1410 | ||
e51c7be2 JH |
1411 | /* Called from both server and client code, to do preliminary initialization |
1412 | of the library. We allocate and return a context structure. | |
059ec3d9 PH |
1413 | |
1414 | Arguments: | |
946ecbe0 | 1415 | ctxp returned SSL context |
059ec3d9 PH |
1416 | host connected host, if client; NULL if server |
1417 | dhparam DH parameter file | |
1418 | certificate certificate file | |
1419 | privatekey private key | |
f5d78688 | 1420 | ocsp_file file of stapling info (server); flag for require ocsp (client) |
059ec3d9 | 1421 | addr address if client; NULL if server (for some randomness) |
946ecbe0 | 1422 | cbp place to put allocated callback context |
cf0c6164 | 1423 | errstr error string pointer |
059ec3d9 PH |
1424 | |
1425 | Returns: OK/DEFER/FAIL | |
1426 | */ | |
1427 | ||
1428 | static int | |
817d9f57 | 1429 | tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate, |
3f7eeb86 | 1430 | uschar *privatekey, |
f2de3a33 | 1431 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1432 | uschar *ocsp_file, |
1433 | #endif | |
cf0c6164 | 1434 | address_item *addr, tls_ext_ctx_cb ** cbp, uschar ** errstr) |
059ec3d9 | 1435 | { |
7006ee24 | 1436 | SSL_CTX * ctx; |
77bb000f | 1437 | long init_options; |
7be682ca | 1438 | int rc; |
a7538db1 | 1439 | tls_ext_ctx_cb * cbinfo; |
7be682ca PP |
1440 | |
1441 | cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); | |
1442 | cbinfo->certificate = certificate; | |
1443 | cbinfo->privatekey = privatekey; | |
f2de3a33 | 1444 | #ifndef DISABLE_OCSP |
c3033f13 | 1445 | cbinfo->verify_stack = NULL; |
f5d78688 JH |
1446 | if ((cbinfo->is_server = host==NULL)) |
1447 | { | |
1448 | cbinfo->u_ocsp.server.file = ocsp_file; | |
1449 | cbinfo->u_ocsp.server.file_expanded = NULL; | |
1450 | cbinfo->u_ocsp.server.response = NULL; | |
1451 | } | |
1452 | else | |
1453 | cbinfo->u_ocsp.client.verify_store = NULL; | |
3f7eeb86 | 1454 | #endif |
7be682ca | 1455 | cbinfo->dhparam = dhparam; |
0df4ab80 | 1456 | cbinfo->server_cipher_list = NULL; |
7be682ca | 1457 | cbinfo->host = host; |
0cbf2b82 | 1458 | #ifndef DISABLE_EVENT |
a7538db1 JH |
1459 | cbinfo->event_action = NULL; |
1460 | #endif | |
77bb000f | 1461 | |
059ec3d9 PH |
1462 | SSL_load_error_strings(); /* basic set up */ |
1463 | OpenSSL_add_ssl_algorithms(); | |
1464 | ||
c8dfb21d | 1465 | #ifdef EXIM_HAVE_SHA256 |
77bb000f | 1466 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the |
a0475b69 TK |
1467 | list of available digests. */ |
1468 | EVP_add_digest(EVP_sha256()); | |
cf1ef1a9 | 1469 | #endif |
a0475b69 | 1470 | |
f0f5a555 PP |
1471 | /* Create a context. |
1472 | The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant | |
1473 | negotiation in the different methods; as far as I can tell, the only | |
1474 | *_{server,client}_method which allows negotiation is SSLv23, which exists even | |
1475 | when OpenSSL is built without SSLv2 support. | |
1476 | By disabling with openssl_options, we can let admins re-enable with the | |
1477 | existing knob. */ | |
059ec3d9 | 1478 | |
7006ee24 JH |
1479 | if (!(ctx = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method()))) |
1480 | return tls_error(US"SSL_CTX_new", host, NULL, errstr); | |
059ec3d9 PH |
1481 | |
1482 | /* It turns out that we need to seed the random number generator this early in | |
1483 | order to get the full complement of ciphers to work. It took me roughly a day | |
1484 | of work to discover this by experiment. | |
1485 | ||
1486 | On systems that have /dev/urandom, SSL may automatically seed itself from | |
1487 | there. Otherwise, we have to make something up as best we can. Double check | |
1488 | afterwards. */ | |
1489 | ||
1490 | if (!RAND_status()) | |
1491 | { | |
1492 | randstuff r; | |
9e3331ea | 1493 | gettimeofday(&r.tv, NULL); |
059ec3d9 PH |
1494 | r.p = getpid(); |
1495 | ||
1496 | RAND_seed((uschar *)(&r), sizeof(r)); | |
1497 | RAND_seed((uschar *)big_buffer, big_buffer_size); | |
1498 | if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr)); | |
1499 | ||
1500 | if (!RAND_status()) | |
7199e1ee | 1501 | return tls_error(US"RAND_status", host, |
cf0c6164 | 1502 | US"unable to seed random number generator", errstr); |
059ec3d9 PH |
1503 | } |
1504 | ||
1505 | /* Set up the information callback, which outputs if debugging is at a suitable | |
1506 | level. */ | |
1507 | ||
7006ee24 | 1508 | DEBUG(D_tls) SSL_CTX_set_info_callback(ctx, (void (*)())info_callback); |
059ec3d9 | 1509 | |
c80c5570 | 1510 | /* Automatically re-try reads/writes after renegotiation. */ |
7006ee24 | 1511 | (void) SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY); |
c80c5570 | 1512 | |
77bb000f PP |
1513 | /* Apply administrator-supplied work-arounds. |
1514 | Historically we applied just one requested option, | |
1515 | SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we | |
1516 | moved to an administrator-controlled list of options to specify and | |
1517 | grandfathered in the first one as the default value for "openssl_options". | |
059ec3d9 | 1518 | |
77bb000f PP |
1519 | No OpenSSL version number checks: the options we accept depend upon the |
1520 | availability of the option value macros from OpenSSL. */ | |
059ec3d9 | 1521 | |
7006ee24 | 1522 | if (!tls_openssl_options_parse(openssl_options, &init_options)) |
cf0c6164 | 1523 | return tls_error(US"openssl_options parsing failed", host, NULL, errstr); |
77bb000f PP |
1524 | |
1525 | if (init_options) | |
1526 | { | |
1527 | DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); | |
7006ee24 | 1528 | if (!(SSL_CTX_set_options(ctx, init_options))) |
77bb000f | 1529 | return tls_error(string_sprintf( |
cf0c6164 | 1530 | "SSL_CTX_set_option(%#lx)", init_options), host, NULL, errstr); |
77bb000f PP |
1531 | } |
1532 | else | |
1533 | DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); | |
059ec3d9 | 1534 | |
7006ee24 JH |
1535 | /* Disable session cache unconditionally */ |
1536 | ||
1537 | (void) SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF); | |
1538 | ||
059ec3d9 | 1539 | /* Initialize with DH parameters if supplied */ |
10ca4f1c | 1540 | /* Initialize ECDH temp key parameter selection */ |
059ec3d9 | 1541 | |
7006ee24 JH |
1542 | if ( !init_dh(ctx, dhparam, host, errstr) |
1543 | || !init_ecdh(ctx, host, errstr) | |
038597d2 PP |
1544 | ) |
1545 | return DEFER; | |
059ec3d9 | 1546 | |
3f7eeb86 | 1547 | /* Set up certificate and key (and perhaps OCSP info) */ |
059ec3d9 | 1548 | |
7006ee24 | 1549 | if ((rc = tls_expand_session_files(ctx, cbinfo, errstr)) != OK) |
23bb6982 | 1550 | return rc; |
c91535f3 | 1551 | |
c3033f13 JH |
1552 | /* If we need to handle SNI or OCSP, do so */ |
1553 | ||
3bcbbbe2 | 1554 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
c3033f13 JH |
1555 | # ifndef DISABLE_OCSP |
1556 | if (!(cbinfo->verify_stack = sk_X509_new_null())) | |
1557 | { | |
1558 | DEBUG(D_tls) debug_printf("failed to create stack for stapling verify\n"); | |
1559 | return FAIL; | |
1560 | } | |
1561 | # endif | |
1562 | ||
f5d78688 | 1563 | if (host == NULL) /* server */ |
3f0945ff | 1564 | { |
f2de3a33 | 1565 | # ifndef DISABLE_OCSP |
f5d78688 | 1566 | /* We check u_ocsp.server.file, not server.response, because we care about if |
3f7eeb86 PP |
1567 | the option exists, not what the current expansion might be, as SNI might |
1568 | change the certificate and OCSP file in use between now and the time the | |
1569 | callback is invoked. */ | |
f5d78688 | 1570 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1571 | { |
7006ee24 JH |
1572 | SSL_CTX_set_tlsext_status_cb(ctx, tls_server_stapling_cb); |
1573 | SSL_CTX_set_tlsext_status_arg(ctx, cbinfo); | |
3f7eeb86 | 1574 | } |
f5d78688 | 1575 | # endif |
3f0945ff PP |
1576 | /* We always do this, so that $tls_sni is available even if not used in |
1577 | tls_certificate */ | |
7006ee24 JH |
1578 | SSL_CTX_set_tlsext_servername_callback(ctx, tls_servername_cb); |
1579 | SSL_CTX_set_tlsext_servername_arg(ctx, cbinfo); | |
3f0945ff | 1580 | } |
f2de3a33 | 1581 | # ifndef DISABLE_OCSP |
f5d78688 JH |
1582 | else /* client */ |
1583 | if(ocsp_file) /* wanting stapling */ | |
1584 | { | |
1585 | if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new())) | |
1586 | { | |
1587 | DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n"); | |
1588 | return FAIL; | |
1589 | } | |
7006ee24 JH |
1590 | SSL_CTX_set_tlsext_status_cb(ctx, tls_client_stapling_cb); |
1591 | SSL_CTX_set_tlsext_status_arg(ctx, cbinfo); | |
f5d78688 JH |
1592 | } |
1593 | # endif | |
7be682ca | 1594 | #endif |
059ec3d9 | 1595 | |
e51c7be2 | 1596 | cbinfo->verify_cert_hostnames = NULL; |
e51c7be2 | 1597 | |
c8dfb21d | 1598 | #ifdef EXIM_HAVE_EPHEM_RSA_KEX |
059ec3d9 | 1599 | /* Set up the RSA callback */ |
7006ee24 | 1600 | SSL_CTX_set_tmp_rsa_callback(ctx, rsa_callback); |
c8dfb21d | 1601 | #endif |
059ec3d9 PH |
1602 | |
1603 | /* Finally, set the timeout, and we are done */ | |
1604 | ||
7006ee24 | 1605 | SSL_CTX_set_timeout(ctx, ssl_session_timeout); |
059ec3d9 | 1606 | DEBUG(D_tls) debug_printf("Initialized TLS\n"); |
7be682ca | 1607 | |
817d9f57 | 1608 | *cbp = cbinfo; |
7006ee24 | 1609 | *ctxp = ctx; |
7be682ca | 1610 | |
059ec3d9 PH |
1611 | return OK; |
1612 | } | |
1613 | ||
1614 | ||
1615 | ||
1616 | ||
1617 | /************************************************* | |
1618 | * Get name of cipher in use * | |
1619 | *************************************************/ | |
1620 | ||
817d9f57 | 1621 | /* |
059ec3d9 | 1622 | Argument: pointer to an SSL structure for the connection |
817d9f57 JH |
1623 | buffer to use for answer |
1624 | size of buffer | |
1625 | pointer to number of bits for cipher | |
059ec3d9 PH |
1626 | Returns: nothing |
1627 | */ | |
1628 | ||
1629 | static void | |
817d9f57 | 1630 | construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits) |
059ec3d9 | 1631 | { |
57b3a7f5 PP |
1632 | /* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't |
1633 | yet reflect that. It should be a safe change anyway, even 0.9.8 versions have | |
1634 | the accessor functions use const in the prototype. */ | |
1635 | const SSL_CIPHER *c; | |
d9784128 | 1636 | const uschar *ver; |
059ec3d9 | 1637 | |
d9784128 | 1638 | ver = (const uschar *)SSL_get_version(ssl); |
059ec3d9 | 1639 | |
57b3a7f5 | 1640 | c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); |
817d9f57 | 1641 | SSL_CIPHER_get_bits(c, bits); |
059ec3d9 | 1642 | |
817d9f57 JH |
1643 | string_format(cipherbuf, bsize, "%s:%s:%u", ver, |
1644 | SSL_CIPHER_get_name(c), *bits); | |
059ec3d9 PH |
1645 | |
1646 | DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf); | |
1647 | } | |
1648 | ||
1649 | ||
f69979cf JH |
1650 | static void |
1651 | peer_cert(SSL * ssl, tls_support * tlsp, uschar * peerdn, unsigned bsize) | |
1652 | { | |
1653 | /*XXX we might consider a list-of-certs variable for the cert chain. | |
1654 | SSL_get_peer_cert_chain(SSL*). We'd need a new variable type and support | |
1655 | in list-handling functions, also consider the difference between the entire | |
1656 | chain and the elements sent by the peer. */ | |
1657 | ||
1658 | /* Will have already noted peercert on a verify fail; possibly not the leaf */ | |
1659 | if (!tlsp->peercert) | |
1660 | tlsp->peercert = SSL_get_peer_certificate(ssl); | |
1661 | /* Beware anonymous ciphers which lead to server_cert being NULL */ | |
1662 | if (tlsp->peercert) | |
1663 | { | |
1664 | X509_NAME_oneline(X509_get_subject_name(tlsp->peercert), CS peerdn, bsize); | |
1665 | peerdn[bsize-1] = '\0'; | |
1666 | tlsp->peerdn = peerdn; /*XXX a static buffer... */ | |
1667 | } | |
1668 | else | |
1669 | tlsp->peerdn = NULL; | |
1670 | } | |
1671 | ||
1672 | ||
059ec3d9 PH |
1673 | |
1674 | ||
1675 | ||
1676 | /************************************************* | |
1677 | * Set up for verifying certificates * | |
1678 | *************************************************/ | |
1679 | ||
c3033f13 JH |
1680 | /* Load certs from file, return TRUE on success */ |
1681 | ||
1682 | static BOOL | |
1683 | chain_from_pem_file(const uschar * file, STACK_OF(X509) * verify_stack) | |
1684 | { | |
1685 | BIO * bp; | |
1686 | X509 * x; | |
1687 | ||
1688 | if (!(bp = BIO_new_file(CS file, "r"))) return FALSE; | |
1689 | while ((x = PEM_read_bio_X509(bp, NULL, 0, NULL))) | |
1690 | sk_X509_push(verify_stack, x); | |
1691 | BIO_free(bp); | |
1692 | return TRUE; | |
1693 | } | |
1694 | ||
1695 | ||
1696 | ||
059ec3d9 PH |
1697 | /* Called by both client and server startup |
1698 | ||
1699 | Arguments: | |
7be682ca | 1700 | sctx SSL_CTX* to initialise |
059ec3d9 PH |
1701 | certs certs file or NULL |
1702 | crl CRL file or NULL | |
1703 | host NULL in a server; the remote host in a client | |
1704 | optional TRUE if called from a server for a host in tls_try_verify_hosts; | |
1705 | otherwise passed as FALSE | |
983207c1 | 1706 | cert_vfy_cb Callback function for certificate verification |
cf0c6164 | 1707 | errstr error string pointer |
059ec3d9 PH |
1708 | |
1709 | Returns: OK/DEFER/FAIL | |
1710 | */ | |
1711 | ||
1712 | static int | |
983207c1 | 1713 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
cf0c6164 | 1714 | int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr) |
059ec3d9 PH |
1715 | { |
1716 | uschar *expcerts, *expcrl; | |
1717 | ||
cf0c6164 | 1718 | if (!expand_check(certs, US"tls_verify_certificates", &expcerts, errstr)) |
059ec3d9 | 1719 | return DEFER; |
57cc2785 | 1720 | DEBUG(D_tls) debug_printf("tls_verify_certificates: %s\n", expcerts); |
059ec3d9 | 1721 | |
10a831a3 | 1722 | if (expcerts && *expcerts) |
059ec3d9 | 1723 | { |
10a831a3 JH |
1724 | /* Tell the library to use its compiled-in location for the system default |
1725 | CA bundle. Then add the ones specified in the config, if any. */ | |
cb1d7830 | 1726 | |
10a831a3 | 1727 | if (!SSL_CTX_set_default_verify_paths(sctx)) |
cf0c6164 | 1728 | return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL, errstr); |
10a831a3 JH |
1729 | |
1730 | if (Ustrcmp(expcerts, "system") != 0) | |
059ec3d9 | 1731 | { |
cb1d7830 JH |
1732 | struct stat statbuf; |
1733 | ||
cb1d7830 JH |
1734 | if (Ustat(expcerts, &statbuf) < 0) |
1735 | { | |
1736 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1737 | "failed to stat %s for certificates", expcerts); | |
1738 | return DEFER; | |
1739 | } | |
059ec3d9 | 1740 | else |
059ec3d9 | 1741 | { |
cb1d7830 JH |
1742 | uschar *file, *dir; |
1743 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
1744 | { file = NULL; dir = expcerts; } | |
1745 | else | |
c3033f13 JH |
1746 | { |
1747 | file = expcerts; dir = NULL; | |
1748 | #ifndef DISABLE_OCSP | |
1749 | /* In the server if we will be offering an OCSP proof, load chain from | |
1750 | file for verifying the OCSP proof at load time. */ | |
1751 | ||
1752 | if ( !host | |
1753 | && statbuf.st_size > 0 | |
1754 | && server_static_cbinfo->u_ocsp.server.file | |
1755 | && !chain_from_pem_file(file, server_static_cbinfo->verify_stack) | |
1756 | ) | |
1757 | { | |
1758 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1759 | "failed to load cert hain from %s", file); | |
1760 | return DEFER; | |
1761 | } | |
1762 | #endif | |
1763 | } | |
cb1d7830 JH |
1764 | |
1765 | /* If a certificate file is empty, the next function fails with an | |
1766 | unhelpful error message. If we skip it, we get the correct behaviour (no | |
1767 | certificates are recognized, but the error message is still misleading (it | |
c3033f13 | 1768 | says no certificate was supplied). But this is better. */ |
cb1d7830 | 1769 | |
f2f2c91b JH |
1770 | if ( (!file || statbuf.st_size > 0) |
1771 | && !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) | |
cf0c6164 | 1772 | return tls_error(US"SSL_CTX_load_verify_locations", host, NULL, errstr); |
cb1d7830 JH |
1773 | |
1774 | /* Load the list of CAs for which we will accept certs, for sending | |
1775 | to the client. This is only for the one-file tls_verify_certificates | |
1776 | variant. | |
1777 | If a list isn't loaded into the server, but | |
1778 | some verify locations are set, the server end appears to make | |
4c04137d | 1779 | a wildcard request for client certs. |
10a831a3 | 1780 | Meanwhile, the client library as default behaviour *ignores* the list |
cb1d7830 JH |
1781 | we send over the wire - see man SSL_CTX_set_client_cert_cb. |
1782 | Because of this, and that the dir variant is likely only used for | |
1783 | the public-CA bundle (not for a private CA), not worth fixing. | |
1784 | */ | |
f2f2c91b | 1785 | if (file) |
cb1d7830 JH |
1786 | { |
1787 | STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file); | |
f2f2c91b JH |
1788 | |
1789 | DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", | |
cb1d7830 JH |
1790 | sk_X509_NAME_num(names)); |
1791 | SSL_CTX_set_client_CA_list(sctx, names); | |
1792 | } | |
059ec3d9 PH |
1793 | } |
1794 | } | |
1795 | ||
1796 | /* Handle a certificate revocation list. */ | |
1797 | ||
10a831a3 | 1798 | #if OPENSSL_VERSION_NUMBER > 0x00907000L |
059ec3d9 | 1799 | |
8b417f2c | 1800 | /* This bit of code is now the version supplied by Lars Mainka. (I have |
10a831a3 | 1801 | merely reformatted it into the Exim code style.) |
8b417f2c | 1802 | |
10a831a3 JH |
1803 | "From here I changed the code to add support for multiple crl's |
1804 | in pem format in one file or to support hashed directory entries in | |
1805 | pem format instead of a file. This method now uses the library function | |
1806 | X509_STORE_load_locations to add the CRL location to the SSL context. | |
1807 | OpenSSL will then handle the verify against CA certs and CRLs by | |
1808 | itself in the verify callback." */ | |
8b417f2c | 1809 | |
cf0c6164 | 1810 | if (!expand_check(crl, US"tls_crl", &expcrl, errstr)) return DEFER; |
10a831a3 | 1811 | if (expcrl && *expcrl) |
059ec3d9 | 1812 | { |
8b417f2c PH |
1813 | struct stat statbufcrl; |
1814 | if (Ustat(expcrl, &statbufcrl) < 0) | |
1815 | { | |
1816 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1817 | "failed to stat %s for certificates revocation lists", expcrl); | |
1818 | return DEFER; | |
1819 | } | |
1820 | else | |
059ec3d9 | 1821 | { |
8b417f2c PH |
1822 | /* is it a file or directory? */ |
1823 | uschar *file, *dir; | |
7be682ca | 1824 | X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx); |
8b417f2c | 1825 | if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR) |
059ec3d9 | 1826 | { |
8b417f2c PH |
1827 | file = NULL; |
1828 | dir = expcrl; | |
1829 | DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir); | |
059ec3d9 PH |
1830 | } |
1831 | else | |
1832 | { | |
8b417f2c PH |
1833 | file = expcrl; |
1834 | dir = NULL; | |
1835 | DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); | |
059ec3d9 | 1836 | } |
8b417f2c | 1837 | if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) |
cf0c6164 | 1838 | return tls_error(US"X509_STORE_load_locations", host, NULL, errstr); |
8b417f2c PH |
1839 | |
1840 | /* setting the flags to check against the complete crl chain */ | |
1841 | ||
1842 | X509_STORE_set_flags(cvstore, | |
1843 | X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL); | |
059ec3d9 | 1844 | } |
059ec3d9 PH |
1845 | } |
1846 | ||
10a831a3 | 1847 | #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ |
059ec3d9 PH |
1848 | |
1849 | /* If verification is optional, don't fail if no certificate */ | |
1850 | ||
7be682ca | 1851 | SSL_CTX_set_verify(sctx, |
059ec3d9 | 1852 | SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT), |
983207c1 | 1853 | cert_vfy_cb); |
059ec3d9 PH |
1854 | } |
1855 | ||
1856 | return OK; | |
1857 | } | |
1858 | ||
1859 | ||
1860 | ||
1861 | /************************************************* | |
1862 | * Start a TLS session in a server * | |
1863 | *************************************************/ | |
1864 | ||
1865 | /* This is called when Exim is running as a server, after having received | |
1866 | the STARTTLS command. It must respond to that command, and then negotiate | |
1867 | a TLS session. | |
1868 | ||
1869 | Arguments: | |
1870 | require_ciphers allowed ciphers | |
cf0c6164 | 1871 | errstr pointer to error message |
059ec3d9 PH |
1872 | |
1873 | Returns: OK on success | |
1874 | DEFER for errors before the start of the negotiation | |
4c04137d | 1875 | FAIL for errors during the negotiation; the server can't |
059ec3d9 PH |
1876 | continue running. |
1877 | */ | |
1878 | ||
1879 | int | |
cf0c6164 | 1880 | tls_server_start(const uschar * require_ciphers, uschar ** errstr) |
059ec3d9 PH |
1881 | { |
1882 | int rc; | |
cf0c6164 JH |
1883 | uschar * expciphers; |
1884 | tls_ext_ctx_cb * cbinfo; | |
f69979cf | 1885 | static uschar peerdn[256]; |
817d9f57 | 1886 | static uschar cipherbuf[256]; |
059ec3d9 PH |
1887 | |
1888 | /* Check for previous activation */ | |
1889 | ||
817d9f57 | 1890 | if (tls_in.active >= 0) |
059ec3d9 | 1891 | { |
cf0c6164 | 1892 | tls_error(US"STARTTLS received after TLS started", NULL, US"", errstr); |
925ac8e4 | 1893 | smtp_printf("554 Already in TLS\r\n", FALSE); |
059ec3d9 PH |
1894 | return FAIL; |
1895 | } | |
1896 | ||
1897 | /* Initialize the SSL library. If it fails, it will already have logged | |
1898 | the error. */ | |
1899 | ||
817d9f57 | 1900 | rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey, |
f2de3a33 | 1901 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1902 | tls_ocsp_file, |
1903 | #endif | |
cf0c6164 | 1904 | NULL, &server_static_cbinfo, errstr); |
059ec3d9 | 1905 | if (rc != OK) return rc; |
817d9f57 | 1906 | cbinfo = server_static_cbinfo; |
059ec3d9 | 1907 | |
cf0c6164 | 1908 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers, errstr)) |
059ec3d9 PH |
1909 | return FAIL; |
1910 | ||
1911 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
17c76198 PP |
1912 | were historically separated by underscores. So that I can use either form in my |
1913 | tests, and also for general convenience, we turn underscores into hyphens here. | |
1914 | */ | |
059ec3d9 | 1915 | |
c3033f13 | 1916 | if (expciphers) |
059ec3d9 | 1917 | { |
c3033f13 | 1918 | uschar * s = expciphers; |
059ec3d9 PH |
1919 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } |
1920 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1921 | if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) |
cf0c6164 | 1922 | return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL, errstr); |
7be682ca | 1923 | cbinfo->server_cipher_list = expciphers; |
059ec3d9 PH |
1924 | } |
1925 | ||
1926 | /* If this is a host for which certificate verification is mandatory or | |
1927 | optional, set up appropriately. */ | |
1928 | ||
817d9f57 | 1929 | tls_in.certificate_verified = FALSE; |
53a7196b JH |
1930 | #ifdef EXPERIMENTAL_DANE |
1931 | tls_in.dane_verified = FALSE; | |
1932 | #endif | |
a2ff477a | 1933 | server_verify_callback_called = FALSE; |
059ec3d9 PH |
1934 | |
1935 | if (verify_check_host(&tls_verify_hosts) == OK) | |
1936 | { | |
983207c1 | 1937 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
cf0c6164 | 1938 | FALSE, verify_callback_server, errstr); |
059ec3d9 | 1939 | if (rc != OK) return rc; |
a2ff477a | 1940 | server_verify_optional = FALSE; |
059ec3d9 PH |
1941 | } |
1942 | else if (verify_check_host(&tls_try_verify_hosts) == OK) | |
1943 | { | |
983207c1 | 1944 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
cf0c6164 | 1945 | TRUE, verify_callback_server, errstr); |
059ec3d9 | 1946 | if (rc != OK) return rc; |
a2ff477a | 1947 | server_verify_optional = TRUE; |
059ec3d9 PH |
1948 | } |
1949 | ||
1950 | /* Prepare for new connection */ | |
1951 | ||
cf0c6164 JH |
1952 | if (!(server_ssl = SSL_new(server_ctx))) |
1953 | return tls_error(US"SSL_new", NULL, NULL, errstr); | |
da3ad30d PP |
1954 | |
1955 | /* Warning: we used to SSL_clear(ssl) here, it was removed. | |
1956 | * | |
1957 | * With the SSL_clear(), we get strange interoperability bugs with | |
1958 | * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in | |
1959 | * OpenSSL itself, as a clear should not lead to inability to follow protocols. | |
1960 | * | |
1961 | * The SSL_clear() call is to let an existing SSL* be reused, typically after | |
1962 | * session shutdown. In this case, we have a brand new object and there's no | |
1963 | * obvious reason to immediately clear it. I'm guessing that this was | |
1964 | * originally added because of incomplete initialisation which the clear fixed, | |
1965 | * in some historic release. | |
1966 | */ | |
059ec3d9 PH |
1967 | |
1968 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
1969 | on connection, where outputting anything now upsets the clients and tends to | |
1970 | make them disconnect. We need to have an explicit fflush() here, to force out | |
1971 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
1972 | mode, the fflush() happens when smtp_getc() is called. */ | |
1973 | ||
817d9f57 JH |
1974 | SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1975 | if (!tls_in.on_connect) | |
059ec3d9 | 1976 | { |
925ac8e4 | 1977 | smtp_printf("220 TLS go ahead\r\n", FALSE); |
059ec3d9 PH |
1978 | fflush(smtp_out); |
1979 | } | |
1980 | ||
1981 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
1982 | that the OpenSSL library doesn't. */ | |
1983 | ||
817d9f57 JH |
1984 | SSL_set_wfd(server_ssl, fileno(smtp_out)); |
1985 | SSL_set_rfd(server_ssl, fileno(smtp_in)); | |
1986 | SSL_set_accept_state(server_ssl); | |
059ec3d9 PH |
1987 | |
1988 | DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); | |
1989 | ||
1990 | sigalrm_seen = FALSE; | |
1991 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 | 1992 | rc = SSL_accept(server_ssl); |
059ec3d9 PH |
1993 | alarm(0); |
1994 | ||
1995 | if (rc <= 0) | |
1996 | { | |
cf0c6164 | 1997 | (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr); |
059ec3d9 PH |
1998 | return FAIL; |
1999 | } | |
2000 | ||
2001 | DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); | |
2002 | ||
2003 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
2004 | and initialize things. */ | |
2005 | ||
f69979cf JH |
2006 | peer_cert(server_ssl, &tls_in, peerdn, sizeof(peerdn)); |
2007 | ||
817d9f57 JH |
2008 | construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits); |
2009 | tls_in.cipher = cipherbuf; | |
059ec3d9 PH |
2010 | |
2011 | DEBUG(D_tls) | |
2012 | { | |
2013 | uschar buf[2048]; | |
817d9f57 | 2014 | if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL) |
059ec3d9 PH |
2015 | debug_printf("Shared ciphers: %s\n", buf); |
2016 | } | |
2017 | ||
9d1c15ef JH |
2018 | /* Record the certificate we presented */ |
2019 | { | |
2020 | X509 * crt = SSL_get_certificate(server_ssl); | |
2021 | tls_in.ourcert = crt ? X509_dup(crt) : NULL; | |
2022 | } | |
059ec3d9 | 2023 | |
817d9f57 JH |
2024 | /* Only used by the server-side tls (tls_in), including tls_getc. |
2025 | Client-side (tls_out) reads (seem to?) go via | |
2026 | smtp_read_response()/ip_recv(). | |
2027 | Hence no need to duplicate for _in and _out. | |
2028 | */ | |
059ec3d9 PH |
2029 | ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
2030 | ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; | |
2031 | ssl_xfer_eof = ssl_xfer_error = 0; | |
2032 | ||
2033 | receive_getc = tls_getc; | |
0d81dabc | 2034 | receive_getbuf = tls_getbuf; |
584e96c6 | 2035 | receive_get_cache = tls_get_cache; |
059ec3d9 PH |
2036 | receive_ungetc = tls_ungetc; |
2037 | receive_feof = tls_feof; | |
2038 | receive_ferror = tls_ferror; | |
58eb016e | 2039 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 2040 | |
817d9f57 | 2041 | tls_in.active = fileno(smtp_out); |
059ec3d9 PH |
2042 | return OK; |
2043 | } | |
2044 | ||
2045 | ||
2046 | ||
2047 | ||
043b1248 JH |
2048 | static int |
2049 | tls_client_basic_ctx_init(SSL_CTX * ctx, | |
cf0c6164 JH |
2050 | host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo, |
2051 | uschar ** errstr) | |
043b1248 JH |
2052 | { |
2053 | int rc; | |
94431adb | 2054 | /* stick to the old behaviour for compatibility if tls_verify_certificates is |
043b1248 JH |
2055 | set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only |
2056 | the specified host patterns if one of them is defined */ | |
2057 | ||
610ff438 JH |
2058 | if ( ( !ob->tls_verify_hosts |
2059 | && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) | |
2060 | ) | |
5130845b | 2061 | || (verify_check_given_host(&ob->tls_verify_hosts, host) == OK) |
aa2a70ba | 2062 | ) |
043b1248 | 2063 | client_verify_optional = FALSE; |
5130845b | 2064 | else if (verify_check_given_host(&ob->tls_try_verify_hosts, host) == OK) |
aa2a70ba JH |
2065 | client_verify_optional = TRUE; |
2066 | else | |
2067 | return OK; | |
2068 | ||
2069 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
cf0c6164 JH |
2070 | ob->tls_crl, host, client_verify_optional, verify_callback_client, |
2071 | errstr)) != OK) | |
aa2a70ba | 2072 | return rc; |
043b1248 | 2073 | |
5130845b | 2074 | if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK) |
043b1248 | 2075 | { |
4af0d74a | 2076 | cbinfo->verify_cert_hostnames = |
8c5d388a | 2077 | #ifdef SUPPORT_I18N |
4af0d74a JH |
2078 | string_domain_utf8_to_alabel(host->name, NULL); |
2079 | #else | |
2080 | host->name; | |
2081 | #endif | |
aa2a70ba JH |
2082 | DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", |
2083 | cbinfo->verify_cert_hostnames); | |
043b1248 | 2084 | } |
043b1248 JH |
2085 | return OK; |
2086 | } | |
059ec3d9 | 2087 | |
fde080a4 JH |
2088 | |
2089 | #ifdef EXPERIMENTAL_DANE | |
fde080a4 | 2090 | static int |
cf0c6164 | 2091 | dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa, uschar ** errstr) |
fde080a4 JH |
2092 | { |
2093 | dns_record * rr; | |
2094 | dns_scan dnss; | |
2095 | const char * hostnames[2] = { CS host->name, NULL }; | |
2096 | int found = 0; | |
2097 | ||
2098 | if (DANESSL_init(ssl, NULL, hostnames) != 1) | |
cf0c6164 | 2099 | return tls_error(US"hostnames load", host, NULL, errstr); |
fde080a4 JH |
2100 | |
2101 | for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); | |
2102 | rr; | |
2103 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) | |
2104 | ) if (rr->type == T_TLSA) | |
2105 | { | |
c3033f13 | 2106 | const uschar * p = rr->data; |
fde080a4 JH |
2107 | uint8_t usage, selector, mtype; |
2108 | const char * mdname; | |
2109 | ||
fde080a4 | 2110 | usage = *p++; |
133d2546 JH |
2111 | |
2112 | /* Only DANE-TA(2) and DANE-EE(3) are supported */ | |
2113 | if (usage != 2 && usage != 3) continue; | |
2114 | ||
fde080a4 JH |
2115 | selector = *p++; |
2116 | mtype = *p++; | |
2117 | ||
2118 | switch (mtype) | |
2119 | { | |
133d2546 JH |
2120 | default: continue; /* Only match-types 0, 1, 2 are supported */ |
2121 | case 0: mdname = NULL; break; | |
2122 | case 1: mdname = "sha256"; break; | |
2123 | case 2: mdname = "sha512"; break; | |
fde080a4 JH |
2124 | } |
2125 | ||
133d2546 | 2126 | found++; |
fde080a4 JH |
2127 | switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3)) |
2128 | { | |
2129 | default: | |
cf0c6164 | 2130 | return tls_error(US"tlsa load", host, NULL, errstr); |
c035b645 | 2131 | case 0: /* action not taken */ |
fde080a4 JH |
2132 | case 1: break; |
2133 | } | |
594706ea JH |
2134 | |
2135 | tls_out.tlsa_usage |= 1<<usage; | |
fde080a4 JH |
2136 | } |
2137 | ||
2138 | if (found) | |
2139 | return OK; | |
2140 | ||
133d2546 | 2141 | log_write(0, LOG_MAIN, "DANE error: No usable TLSA records"); |
6ebd79ec | 2142 | return DEFER; |
fde080a4 JH |
2143 | } |
2144 | #endif /*EXPERIMENTAL_DANE*/ | |
2145 | ||
2146 | ||
2147 | ||
059ec3d9 PH |
2148 | /************************************************* |
2149 | * Start a TLS session in a client * | |
2150 | *************************************************/ | |
2151 | ||
2152 | /* Called from the smtp transport after STARTTLS has been accepted. | |
2153 | ||
2154 | Argument: | |
2155 | fd the fd of the connection | |
2156 | host connected host (for messages) | |
83da1223 | 2157 | addr the first address |
a7538db1 | 2158 | tb transport (always smtp) |
0e66b3b6 | 2159 | tlsa_dnsa tlsa lookup, if DANE, else null |
cf0c6164 | 2160 | errstr error string pointer |
059ec3d9 PH |
2161 | |
2162 | Returns: OK on success | |
2163 | FAIL otherwise - note that tls_error() will not give DEFER | |
2164 | because this is not a server | |
2165 | */ | |
2166 | ||
2167 | int | |
f5d78688 | 2168 | tls_client_start(int fd, host_item *host, address_item *addr, |
cf0c6164 | 2169 | transport_instance * tb, |
0e66b3b6 | 2170 | #ifdef EXPERIMENTAL_DANE |
cf0c6164 | 2171 | dns_answer * tlsa_dnsa, |
0e66b3b6 | 2172 | #endif |
cf0c6164 | 2173 | uschar ** errstr) |
059ec3d9 | 2174 | { |
a7538db1 JH |
2175 | smtp_transport_options_block * ob = |
2176 | (smtp_transport_options_block *)tb->options_block; | |
f69979cf | 2177 | static uschar peerdn[256]; |
868f5672 | 2178 | uschar * expciphers; |
059ec3d9 | 2179 | int rc; |
817d9f57 | 2180 | static uschar cipherbuf[256]; |
043b1248 JH |
2181 | |
2182 | #ifndef DISABLE_OCSP | |
043b1248 | 2183 | BOOL request_ocsp = FALSE; |
6634ac8d | 2184 | BOOL require_ocsp = FALSE; |
043b1248 | 2185 | #endif |
043b1248 JH |
2186 | |
2187 | #ifdef EXPERIMENTAL_DANE | |
594706ea | 2188 | tls_out.tlsa_usage = 0; |
043b1248 JH |
2189 | #endif |
2190 | ||
f2de3a33 | 2191 | #ifndef DISABLE_OCSP |
043b1248 | 2192 | { |
4f59c424 JH |
2193 | # ifdef EXPERIMENTAL_DANE |
2194 | if ( tlsa_dnsa | |
2195 | && ob->hosts_request_ocsp[0] == '*' | |
2196 | && ob->hosts_request_ocsp[1] == '\0' | |
2197 | ) | |
2198 | { | |
2199 | /* Unchanged from default. Use a safer one under DANE */ | |
2200 | request_ocsp = TRUE; | |
2201 | ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} " | |
2202 | " {= {4}{$tls_out_tlsa_usage}} } " | |
2203 | " {*}{}}"; | |
2204 | } | |
2205 | # endif | |
2206 | ||
5130845b JH |
2207 | if ((require_ocsp = |
2208 | verify_check_given_host(&ob->hosts_require_ocsp, host) == OK)) | |
fca41d5a JH |
2209 | request_ocsp = TRUE; |
2210 | else | |
fca41d5a | 2211 | # ifdef EXPERIMENTAL_DANE |
4f59c424 | 2212 | if (!request_ocsp) |
fca41d5a | 2213 | # endif |
5130845b JH |
2214 | request_ocsp = |
2215 | verify_check_given_host(&ob->hosts_request_ocsp, host) == OK; | |
043b1248 | 2216 | } |
f5d78688 | 2217 | #endif |
059ec3d9 | 2218 | |
65867078 JH |
2219 | rc = tls_init(&client_ctx, host, NULL, |
2220 | ob->tls_certificate, ob->tls_privatekey, | |
f2de3a33 | 2221 | #ifndef DISABLE_OCSP |
44662487 | 2222 | (void *)(long)request_ocsp, |
3f7eeb86 | 2223 | #endif |
cf0c6164 | 2224 | addr, &client_static_cbinfo, errstr); |
059ec3d9 PH |
2225 | if (rc != OK) return rc; |
2226 | ||
817d9f57 | 2227 | tls_out.certificate_verified = FALSE; |
a2ff477a | 2228 | client_verify_callback_called = FALSE; |
059ec3d9 | 2229 | |
65867078 | 2230 | if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers", |
cf0c6164 | 2231 | &expciphers, errstr)) |
059ec3d9 PH |
2232 | return FAIL; |
2233 | ||
2234 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
2235 | are separated by underscores. So that I can use either form in my tests, and | |
2236 | also for general convenience, we turn underscores into hyphens here. */ | |
2237 | ||
cf0c6164 | 2238 | if (expciphers) |
059ec3d9 PH |
2239 | { |
2240 | uschar *s = expciphers; | |
cf0c6164 | 2241 | while (*s) { if (*s == '_') *s = '-'; s++; } |
059ec3d9 | 2242 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); |
817d9f57 | 2243 | if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers)) |
cf0c6164 | 2244 | return tls_error(US"SSL_CTX_set_cipher_list", host, NULL, errstr); |
059ec3d9 PH |
2245 | } |
2246 | ||
043b1248 | 2247 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 | 2248 | if (tlsa_dnsa) |
a63be306 | 2249 | { |
02af313d JH |
2250 | SSL_CTX_set_verify(client_ctx, |
2251 | SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, | |
2252 | verify_callback_client_dane); | |
e5cccda9 | 2253 | |
043b1248 | 2254 | if (!DANESSL_library_init()) |
cf0c6164 | 2255 | return tls_error(US"library init", host, NULL, errstr); |
043b1248 | 2256 | if (DANESSL_CTX_init(client_ctx) <= 0) |
cf0c6164 | 2257 | return tls_error(US"context init", host, NULL, errstr); |
043b1248 JH |
2258 | } |
2259 | else | |
e51c7be2 | 2260 | |
043b1248 JH |
2261 | #endif |
2262 | ||
cf0c6164 JH |
2263 | if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob, |
2264 | client_static_cbinfo, errstr)) != OK) | |
65867078 | 2265 | return rc; |
059ec3d9 | 2266 | |
65867078 | 2267 | if ((client_ssl = SSL_new(client_ctx)) == NULL) |
cf0c6164 | 2268 | return tls_error(US"SSL_new", host, NULL, errstr); |
817d9f57 JH |
2269 | SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx)); |
2270 | SSL_set_fd(client_ssl, fd); | |
2271 | SSL_set_connect_state(client_ssl); | |
059ec3d9 | 2272 | |
65867078 | 2273 | if (ob->tls_sni) |
3f0945ff | 2274 | { |
cf0c6164 | 2275 | if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni, errstr)) |
3f0945ff | 2276 | return FAIL; |
cf0c6164 | 2277 | if (!tls_out.sni) |
2c9a0e86 PP |
2278 | { |
2279 | DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n"); | |
2280 | } | |
ec4b68e5 | 2281 | else if (!Ustrlen(tls_out.sni)) |
817d9f57 | 2282 | tls_out.sni = NULL; |
3f0945ff PP |
2283 | else |
2284 | { | |
35731706 | 2285 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 JH |
2286 | DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni); |
2287 | SSL_set_tlsext_host_name(client_ssl, tls_out.sni); | |
35731706 | 2288 | #else |
66802652 | 2289 | log_write(0, LOG_MAIN, "SNI unusable with this OpenSSL library version; ignoring \"%s\"\n", |
02d9264f | 2290 | tls_out.sni); |
35731706 | 2291 | #endif |
3f0945ff PP |
2292 | } |
2293 | } | |
2294 | ||
594706ea | 2295 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 | 2296 | if (tlsa_dnsa) |
cf0c6164 | 2297 | if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa, errstr)) != OK) |
594706ea JH |
2298 | return rc; |
2299 | #endif | |
2300 | ||
f2de3a33 | 2301 | #ifndef DISABLE_OCSP |
f5d78688 JH |
2302 | /* Request certificate status at connection-time. If the server |
2303 | does OCSP stapling we will get the callback (set in tls_init()) */ | |
b50c8b84 | 2304 | # ifdef EXPERIMENTAL_DANE |
594706ea JH |
2305 | if (request_ocsp) |
2306 | { | |
2307 | const uschar * s; | |
41afb5cb JH |
2308 | if ( ((s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage")) |
2309 | || ((s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage")) | |
594706ea JH |
2310 | ) |
2311 | { /* Re-eval now $tls_out_tlsa_usage is populated. If | |
2312 | this means we avoid the OCSP request, we wasted the setup | |
2313 | cost in tls_init(). */ | |
5130845b JH |
2314 | require_ocsp = verify_check_given_host(&ob->hosts_require_ocsp, host) == OK; |
2315 | request_ocsp = require_ocsp | |
2316 | || verify_check_given_host(&ob->hosts_request_ocsp, host) == OK; | |
594706ea JH |
2317 | } |
2318 | } | |
b50c8b84 JH |
2319 | # endif |
2320 | ||
44662487 JH |
2321 | if (request_ocsp) |
2322 | { | |
f5d78688 | 2323 | SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp); |
44662487 JH |
2324 | client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp; |
2325 | tls_out.ocsp = OCSP_NOT_RESP; | |
2326 | } | |
f5d78688 JH |
2327 | #endif |
2328 | ||
0cbf2b82 | 2329 | #ifndef DISABLE_EVENT |
774ef2d7 | 2330 | client_static_cbinfo->event_action = tb->event_action; |
a7538db1 | 2331 | #endif |
043b1248 | 2332 | |
059ec3d9 PH |
2333 | /* There doesn't seem to be a built-in timeout on connection. */ |
2334 | ||
2335 | DEBUG(D_tls) debug_printf("Calling SSL_connect\n"); | |
2336 | sigalrm_seen = FALSE; | |
65867078 | 2337 | alarm(ob->command_timeout); |
817d9f57 | 2338 | rc = SSL_connect(client_ssl); |
059ec3d9 PH |
2339 | alarm(0); |
2340 | ||
043b1248 | 2341 | #ifdef EXPERIMENTAL_DANE |
0e66b3b6 | 2342 | if (tlsa_dnsa) |
fde080a4 | 2343 | DANESSL_cleanup(client_ssl); |
043b1248 JH |
2344 | #endif |
2345 | ||
059ec3d9 | 2346 | if (rc <= 0) |
cf0c6164 JH |
2347 | return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL, |
2348 | errstr); | |
059ec3d9 PH |
2349 | |
2350 | DEBUG(D_tls) debug_printf("SSL_connect succeeded\n"); | |
2351 | ||
f69979cf | 2352 | peer_cert(client_ssl, &tls_out, peerdn, sizeof(peerdn)); |
059ec3d9 | 2353 | |
817d9f57 JH |
2354 | construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits); |
2355 | tls_out.cipher = cipherbuf; | |
059ec3d9 | 2356 | |
9d1c15ef JH |
2357 | /* Record the certificate we presented */ |
2358 | { | |
2359 | X509 * crt = SSL_get_certificate(client_ssl); | |
2360 | tls_out.ourcert = crt ? X509_dup(crt) : NULL; | |
2361 | } | |
2362 | ||
817d9f57 | 2363 | tls_out.active = fd; |
059ec3d9 PH |
2364 | return OK; |
2365 | } | |
2366 | ||
2367 | ||
2368 | ||
2369 | ||
2370 | ||
0d81dabc JH |
2371 | static BOOL |
2372 | tls_refill(unsigned lim) | |
2373 | { | |
2374 | int error; | |
2375 | int inbytes; | |
2376 | ||
2377 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl, | |
2378 | ssl_xfer_buffer, ssl_xfer_buffer_size); | |
2379 | ||
2380 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
2381 | inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, | |
2382 | MIN(ssl_xfer_buffer_size, lim)); | |
2383 | error = SSL_get_error(server_ssl, inbytes); | |
2384 | alarm(0); | |
2385 | ||
2386 | /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been | |
2387 | closed down, not that the socket itself has been closed down. Revert to | |
2388 | non-SSL handling. */ | |
2389 | ||
2390 | if (error == SSL_ERROR_ZERO_RETURN) | |
2391 | { | |
2392 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2393 | ||
2394 | receive_getc = smtp_getc; | |
2395 | receive_getbuf = smtp_getbuf; | |
2396 | receive_get_cache = smtp_get_cache; | |
2397 | receive_ungetc = smtp_ungetc; | |
2398 | receive_feof = smtp_feof; | |
2399 | receive_ferror = smtp_ferror; | |
2400 | receive_smtp_buffered = smtp_buffered; | |
2401 | ||
2402 | SSL_free(server_ssl); | |
2403 | server_ssl = NULL; | |
2404 | tls_in.active = -1; | |
2405 | tls_in.bits = 0; | |
2406 | tls_in.cipher = NULL; | |
2407 | tls_in.peerdn = NULL; | |
2408 | tls_in.sni = NULL; | |
2409 | ||
2410 | return FALSE; | |
2411 | } | |
2412 | ||
2413 | /* Handle genuine errors */ | |
2414 | ||
2415 | else if (error == SSL_ERROR_SSL) | |
2416 | { | |
2417 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2418 | log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); | |
2419 | ssl_xfer_error = 1; | |
2420 | return FALSE; | |
2421 | } | |
2422 | ||
2423 | else if (error != SSL_ERROR_NONE) | |
2424 | { | |
2425 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
2426 | ssl_xfer_error = 1; | |
2427 | return FALSE; | |
2428 | } | |
2429 | ||
2430 | #ifndef DISABLE_DKIM | |
2431 | dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); | |
2432 | #endif | |
2433 | ssl_xfer_buffer_hwm = inbytes; | |
2434 | ssl_xfer_buffer_lwm = 0; | |
2435 | return TRUE; | |
2436 | } | |
2437 | ||
2438 | ||
059ec3d9 PH |
2439 | /************************************************* |
2440 | * TLS version of getc * | |
2441 | *************************************************/ | |
2442 | ||
2443 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
2444 | it refills the buffer via the SSL reading function. | |
2445 | ||
bd8fbe36 | 2446 | Arguments: lim Maximum amount to read/buffer |
059ec3d9 | 2447 | Returns: the next character or EOF |
817d9f57 JH |
2448 | |
2449 | Only used by the server-side TLS. | |
059ec3d9 PH |
2450 | */ |
2451 | ||
2452 | int | |
bd8fbe36 | 2453 | tls_getc(unsigned lim) |
059ec3d9 PH |
2454 | { |
2455 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) | |
0d81dabc JH |
2456 | if (!tls_refill(lim)) |
2457 | return ssl_xfer_error ? EOF : smtp_getc(lim); | |
059ec3d9 | 2458 | |
0d81dabc | 2459 | /* Something in the buffer; return next uschar */ |
059ec3d9 | 2460 | |
0d81dabc JH |
2461 | return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; |
2462 | } | |
059ec3d9 | 2463 | |
0d81dabc JH |
2464 | uschar * |
2465 | tls_getbuf(unsigned * len) | |
2466 | { | |
2467 | unsigned size; | |
2468 | uschar * buf; | |
ba084640 | 2469 | |
0d81dabc JH |
2470 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) |
2471 | if (!tls_refill(*len)) | |
059ec3d9 | 2472 | { |
0d81dabc JH |
2473 | if (!ssl_xfer_error) return smtp_getbuf(len); |
2474 | *len = 0; | |
2475 | return NULL; | |
059ec3d9 | 2476 | } |
c80c5570 | 2477 | |
0d81dabc JH |
2478 | if ((size = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm) > *len) |
2479 | size = *len; | |
2480 | buf = &ssl_xfer_buffer[ssl_xfer_buffer_lwm]; | |
2481 | ssl_xfer_buffer_lwm += size; | |
2482 | *len = size; | |
2483 | return buf; | |
059ec3d9 PH |
2484 | } |
2485 | ||
0d81dabc | 2486 | |
584e96c6 JH |
2487 | void |
2488 | tls_get_cache() | |
2489 | { | |
9960d1e5 | 2490 | #ifndef DISABLE_DKIM |
584e96c6 JH |
2491 | int n = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm; |
2492 | if (n > 0) | |
2493 | dkim_exim_verify_feed(ssl_xfer_buffer+ssl_xfer_buffer_lwm, n); | |
584e96c6 | 2494 | #endif |
9960d1e5 | 2495 | } |
584e96c6 | 2496 | |
059ec3d9 | 2497 | |
925ac8e4 JH |
2498 | BOOL |
2499 | tls_could_read(void) | |
2500 | { | |
a5ffa9b4 | 2501 | return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm || SSL_pending(server_ssl) > 0; |
925ac8e4 JH |
2502 | } |
2503 | ||
059ec3d9 PH |
2504 | |
2505 | /************************************************* | |
2506 | * Read bytes from TLS channel * | |
2507 | *************************************************/ | |
2508 | ||
2509 | /* | |
2510 | Arguments: | |
2511 | buff buffer of data | |
2512 | len size of buffer | |
2513 | ||
2514 | Returns: the number of bytes read | |
2515 | -1 after a failed read | |
817d9f57 JH |
2516 | |
2517 | Only used by the client-side TLS. | |
059ec3d9 PH |
2518 | */ |
2519 | ||
2520 | int | |
389ca47a | 2521 | tls_read(BOOL is_server, uschar *buff, size_t len) |
059ec3d9 | 2522 | { |
389ca47a | 2523 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 PH |
2524 | int inbytes; |
2525 | int error; | |
2526 | ||
389ca47a | 2527 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl, |
c80c5570 | 2528 | buff, (unsigned int)len); |
059ec3d9 | 2529 | |
389ca47a JH |
2530 | inbytes = SSL_read(ssl, CS buff, len); |
2531 | error = SSL_get_error(ssl, inbytes); | |
059ec3d9 PH |
2532 | |
2533 | if (error == SSL_ERROR_ZERO_RETURN) | |
2534 | { | |
2535 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2536 | return -1; | |
2537 | } | |
2538 | else if (error != SSL_ERROR_NONE) | |
059ec3d9 | 2539 | return -1; |
059ec3d9 PH |
2540 | |
2541 | return inbytes; | |
2542 | } | |
2543 | ||
2544 | ||
2545 | ||
2546 | ||
2547 | ||
2548 | /************************************************* | |
2549 | * Write bytes down TLS channel * | |
2550 | *************************************************/ | |
2551 | ||
2552 | /* | |
2553 | Arguments: | |
817d9f57 | 2554 | is_server channel specifier |
059ec3d9 PH |
2555 | buff buffer of data |
2556 | len number of bytes | |
925ac8e4 | 2557 | more further data expected soon |
059ec3d9 PH |
2558 | |
2559 | Returns: the number of bytes after a successful write, | |
2560 | -1 after a failed write | |
817d9f57 JH |
2561 | |
2562 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2563 | */ |
2564 | ||
2565 | int | |
925ac8e4 | 2566 | tls_write(BOOL is_server, const uschar *buff, size_t len, BOOL more) |
059ec3d9 | 2567 | { |
a5ffa9b4 | 2568 | int outbytes, error, left; |
817d9f57 | 2569 | SSL *ssl = is_server ? server_ssl : client_ssl; |
a5ffa9b4 JH |
2570 | static uschar * corked = NULL; |
2571 | static int c_size = 0, c_len = 0; | |
2572 | ||
2573 | DEBUG(D_tls) debug_printf("%s(%p, %d%s)\n", __FUNCTION__, | |
2574 | buff, left, more ? ", more" : ""); | |
2575 | ||
2576 | /* Lacking a CORK or MSG_MORE facility (such as GnuTLS has) we copy data when | |
2577 | "more" is notified. This hack is only ok if small amounts are involved AND only | |
2578 | one stream does it, in one context (i.e. no store reset). Currently it is used | |
2579 | for the responses to the received SMTP MAIL , RCPT, DATA sequence, only. */ | |
2580 | ||
2581 | if (is_server && (more || corked)) | |
2582 | { | |
2583 | corked = string_catn(corked, &c_size, &c_len, buff, len); | |
2584 | if (more) | |
2585 | return len; | |
2586 | buff = CUS corked; | |
2587 | len = c_len; | |
2588 | corked = NULL; c_size = c_len = 0; | |
2589 | } | |
059ec3d9 | 2590 | |
a5ffa9b4 | 2591 | for (left = len; left > 0;) |
059ec3d9 | 2592 | { |
c80c5570 | 2593 | DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left); |
059ec3d9 PH |
2594 | outbytes = SSL_write(ssl, CS buff, left); |
2595 | error = SSL_get_error(ssl, outbytes); | |
2596 | DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error); | |
2597 | switch (error) | |
2598 | { | |
2599 | case SSL_ERROR_SSL: | |
96f5fe4c JH |
2600 | ERR_error_string(ERR_get_error(), ssl_errstring); |
2601 | log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); | |
2602 | return -1; | |
059ec3d9 PH |
2603 | |
2604 | case SSL_ERROR_NONE: | |
96f5fe4c JH |
2605 | left -= outbytes; |
2606 | buff += outbytes; | |
2607 | break; | |
059ec3d9 PH |
2608 | |
2609 | case SSL_ERROR_ZERO_RETURN: | |
96f5fe4c JH |
2610 | log_write(0, LOG_MAIN, "SSL channel closed on write"); |
2611 | return -1; | |
059ec3d9 | 2612 | |
817d9f57 | 2613 | case SSL_ERROR_SYSCALL: |
96f5fe4c JH |
2614 | log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", |
2615 | sender_fullhost ? sender_fullhost : US"<unknown>", | |
2616 | strerror(errno)); | |
2617 | return -1; | |
817d9f57 | 2618 | |
059ec3d9 | 2619 | default: |
96f5fe4c JH |
2620 | log_write(0, LOG_MAIN, "SSL_write error %d", error); |
2621 | return -1; | |
059ec3d9 PH |
2622 | } |
2623 | } | |
2624 | return len; | |
2625 | } | |
2626 | ||
2627 | ||
2628 | ||
2629 | /************************************************* | |
2630 | * Close down a TLS session * | |
2631 | *************************************************/ | |
2632 | ||
2633 | /* This is also called from within a delivery subprocess forked from the | |
2634 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
2635 | would tamper with the SSL session in the parent process). | |
2636 | ||
2637 | Arguments: TRUE if SSL_shutdown is to be called | |
2638 | Returns: nothing | |
817d9f57 JH |
2639 | |
2640 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2641 | */ |
2642 | ||
2643 | void | |
817d9f57 | 2644 | tls_close(BOOL is_server, BOOL shutdown) |
059ec3d9 | 2645 | { |
817d9f57 | 2646 | SSL **sslp = is_server ? &server_ssl : &client_ssl; |
389ca47a | 2647 | int *fdp = is_server ? &tls_in.active : &tls_out.active; |
817d9f57 JH |
2648 | |
2649 | if (*fdp < 0) return; /* TLS was not active */ | |
059ec3d9 PH |
2650 | |
2651 | if (shutdown) | |
2652 | { | |
ec8b777a | 2653 | DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n"); |
817d9f57 | 2654 | SSL_shutdown(*sslp); |
059ec3d9 PH |
2655 | } |
2656 | ||
817d9f57 JH |
2657 | SSL_free(*sslp); |
2658 | *sslp = NULL; | |
059ec3d9 | 2659 | |
817d9f57 | 2660 | *fdp = -1; |
059ec3d9 PH |
2661 | } |
2662 | ||
36f12725 NM |
2663 | |
2664 | ||
2665 | ||
3375e053 PP |
2666 | /************************************************* |
2667 | * Let tls_require_ciphers be checked at startup * | |
2668 | *************************************************/ | |
2669 | ||
2670 | /* The tls_require_ciphers option, if set, must be something which the | |
2671 | library can parse. | |
2672 | ||
2673 | Returns: NULL on success, or error message | |
2674 | */ | |
2675 | ||
2676 | uschar * | |
2677 | tls_validate_require_cipher(void) | |
2678 | { | |
2679 | SSL_CTX *ctx; | |
2680 | uschar *s, *expciphers, *err; | |
2681 | ||
2682 | /* this duplicates from tls_init(), we need a better "init just global | |
2683 | state, for no specific purpose" singleton function of our own */ | |
2684 | ||
2685 | SSL_load_error_strings(); | |
2686 | OpenSSL_add_ssl_algorithms(); | |
2687 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
2688 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the | |
2689 | list of available digests. */ | |
2690 | EVP_add_digest(EVP_sha256()); | |
2691 | #endif | |
2692 | ||
2693 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
2694 | return NULL; | |
2695 | ||
cf0c6164 JH |
2696 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers, |
2697 | &err)) | |
3375e053 PP |
2698 | return US"failed to expand tls_require_ciphers"; |
2699 | ||
2700 | if (!(expciphers && *expciphers)) | |
2701 | return NULL; | |
2702 | ||
2703 | /* normalisation ripped from above */ | |
2704 | s = expciphers; | |
2705 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
2706 | ||
2707 | err = NULL; | |
2708 | ||
2709 | ctx = SSL_CTX_new(SSLv23_server_method()); | |
2710 | if (!ctx) | |
2711 | { | |
2712 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2713 | return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring); | |
2714 | } | |
2715 | ||
2716 | DEBUG(D_tls) | |
2717 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
2718 | ||
2719 | if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) | |
2720 | { | |
2721 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
cf0c6164 JH |
2722 | err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed: %s", |
2723 | expciphers, ssl_errstring); | |
3375e053 PP |
2724 | } |
2725 | ||
2726 | SSL_CTX_free(ctx); | |
2727 | ||
2728 | return err; | |
2729 | } | |
2730 | ||
2731 | ||
2732 | ||
2733 | ||
36f12725 NM |
2734 | /************************************************* |
2735 | * Report the library versions. * | |
2736 | *************************************************/ | |
2737 | ||
2738 | /* There have historically been some issues with binary compatibility in | |
2739 | OpenSSL libraries; if Exim (like many other applications) is built against | |
2740 | one version of OpenSSL but the run-time linker picks up another version, | |
2741 | it can result in serious failures, including crashing with a SIGSEGV. So | |
2742 | report the version found by the compiler and the run-time version. | |
2743 | ||
f64a1e23 PP |
2744 | Note: some OS vendors backport security fixes without changing the version |
2745 | number/string, and the version date remains unchanged. The _build_ date | |
2746 | will change, so we can more usefully assist with version diagnosis by also | |
2747 | reporting the build date. | |
2748 | ||
36f12725 NM |
2749 | Arguments: a FILE* to print the results to |
2750 | Returns: nothing | |
2751 | */ | |
2752 | ||
2753 | void | |
2754 | tls_version_report(FILE *f) | |
2755 | { | |
754a0503 | 2756 | fprintf(f, "Library version: OpenSSL: Compile: %s\n" |
f64a1e23 PP |
2757 | " Runtime: %s\n" |
2758 | " : %s\n", | |
754a0503 | 2759 | OPENSSL_VERSION_TEXT, |
f64a1e23 PP |
2760 | SSLeay_version(SSLEAY_VERSION), |
2761 | SSLeay_version(SSLEAY_BUILT_ON)); | |
2762 | /* third line is 38 characters for the %s and the line is 73 chars long; | |
2763 | the OpenSSL output includes a "built on: " prefix already. */ | |
36f12725 NM |
2764 | } |
2765 | ||
9e3331ea TK |
2766 | |
2767 | ||
2768 | ||
2769 | /************************************************* | |
17c76198 | 2770 | * Random number generation * |
9e3331ea TK |
2771 | *************************************************/ |
2772 | ||
2773 | /* Pseudo-random number generation. The result is not expected to be | |
2774 | cryptographically strong but not so weak that someone will shoot themselves | |
2775 | in the foot using it as a nonce in input in some email header scheme or | |
2776 | whatever weirdness they'll twist this into. The result should handle fork() | |
2777 | and avoid repeating sequences. OpenSSL handles that for us. | |
2778 | ||
2779 | Arguments: | |
2780 | max range maximum | |
2781 | Returns a random number in range [0, max-1] | |
2782 | */ | |
2783 | ||
2784 | int | |
17c76198 | 2785 | vaguely_random_number(int max) |
9e3331ea TK |
2786 | { |
2787 | unsigned int r; | |
2788 | int i, needed_len; | |
de6135a0 PP |
2789 | static pid_t pidlast = 0; |
2790 | pid_t pidnow; | |
9e3331ea TK |
2791 | uschar *p; |
2792 | uschar smallbuf[sizeof(r)]; | |
2793 | ||
2794 | if (max <= 1) | |
2795 | return 0; | |
2796 | ||
de6135a0 PP |
2797 | pidnow = getpid(); |
2798 | if (pidnow != pidlast) | |
2799 | { | |
2800 | /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state | |
2801 | is unique for each thread", this doesn't apparently apply across processes, | |
2802 | so our own warning from vaguely_random_number_fallback() applies here too. | |
2803 | Fix per PostgreSQL. */ | |
2804 | if (pidlast != 0) | |
2805 | RAND_cleanup(); | |
2806 | pidlast = pidnow; | |
2807 | } | |
2808 | ||
9e3331ea TK |
2809 | /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ |
2810 | if (!RAND_status()) | |
2811 | { | |
2812 | randstuff r; | |
2813 | gettimeofday(&r.tv, NULL); | |
2814 | r.p = getpid(); | |
2815 | ||
2816 | RAND_seed((uschar *)(&r), sizeof(r)); | |
2817 | } | |
2818 | /* We're after pseudo-random, not random; if we still don't have enough data | |
2819 | in the internal PRNG then our options are limited. We could sleep and hope | |
2820 | for entropy to come along (prayer technique) but if the system is so depleted | |
2821 | in the first place then something is likely to just keep taking it. Instead, | |
2822 | we'll just take whatever little bit of pseudo-random we can still manage to | |
2823 | get. */ | |
2824 | ||
2825 | needed_len = sizeof(r); | |
2826 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
2827 | asked for a number less than 10. */ | |
2828 | for (r = max, i = 0; r; ++i) | |
2829 | r >>= 1; | |
2830 | i = (i + 7) / 8; | |
2831 | if (i < needed_len) | |
2832 | needed_len = i; | |
2833 | ||
c8dfb21d | 2834 | #ifdef EXIM_HAVE_RAND_PSEUDO |
9e3331ea | 2835 | /* We do not care if crypto-strong */ |
17c76198 | 2836 | i = RAND_pseudo_bytes(smallbuf, needed_len); |
c8dfb21d JH |
2837 | #else |
2838 | i = RAND_bytes(smallbuf, needed_len); | |
2839 | #endif | |
2840 | ||
17c76198 PP |
2841 | if (i < 0) |
2842 | { | |
2843 | DEBUG(D_all) | |
2844 | debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n"); | |
2845 | return vaguely_random_number_fallback(max); | |
2846 | } | |
2847 | ||
9e3331ea TK |
2848 | r = 0; |
2849 | for (p = smallbuf; needed_len; --needed_len, ++p) | |
2850 | { | |
2851 | r *= 256; | |
2852 | r += *p; | |
2853 | } | |
2854 | ||
2855 | /* We don't particularly care about weighted results; if someone wants | |
2856 | smooth distribution and cares enough then they should submit a patch then. */ | |
2857 | return r % max; | |
2858 | } | |
2859 | ||
77bb000f PP |
2860 | |
2861 | ||
2862 | ||
2863 | /************************************************* | |
2864 | * OpenSSL option parse * | |
2865 | *************************************************/ | |
2866 | ||
2867 | /* Parse one option for tls_openssl_options_parse below | |
2868 | ||
2869 | Arguments: | |
2870 | name one option name | |
2871 | value place to store a value for it | |
2872 | Returns success or failure in parsing | |
2873 | */ | |
2874 | ||
2875 | struct exim_openssl_option { | |
2876 | uschar *name; | |
2877 | long value; | |
2878 | }; | |
2879 | /* We could use a macro to expand, but we need the ifdef and not all the | |
2880 | options document which version they were introduced in. Policylet: include | |
2881 | all options unless explicitly for DTLS, let the administrator choose which | |
2882 | to apply. | |
2883 | ||
2884 | This list is current as of: | |
e2fbf4a2 PP |
2885 | ==> 1.0.1b <== |
2886 | Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev | |
2887 | */ | |
77bb000f PP |
2888 | static struct exim_openssl_option exim_openssl_options[] = { |
2889 | /* KEEP SORTED ALPHABETICALLY! */ | |
2890 | #ifdef SSL_OP_ALL | |
73a46702 | 2891 | { US"all", SSL_OP_ALL }, |
77bb000f PP |
2892 | #endif |
2893 | #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION | |
73a46702 | 2894 | { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, |
77bb000f PP |
2895 | #endif |
2896 | #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE | |
73a46702 | 2897 | { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, |
77bb000f PP |
2898 | #endif |
2899 | #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS | |
73a46702 | 2900 | { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, |
77bb000f PP |
2901 | #endif |
2902 | #ifdef SSL_OP_EPHEMERAL_RSA | |
73a46702 | 2903 | { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, |
77bb000f PP |
2904 | #endif |
2905 | #ifdef SSL_OP_LEGACY_SERVER_CONNECT | |
73a46702 | 2906 | { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, |
77bb000f PP |
2907 | #endif |
2908 | #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER | |
73a46702 | 2909 | { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, |
77bb000f PP |
2910 | #endif |
2911 | #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG | |
73a46702 | 2912 | { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, |
77bb000f PP |
2913 | #endif |
2914 | #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING | |
73a46702 | 2915 | { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, |
77bb000f PP |
2916 | #endif |
2917 | #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG | |
73a46702 | 2918 | { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, |
77bb000f PP |
2919 | #endif |
2920 | #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG | |
73a46702 | 2921 | { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, |
77bb000f | 2922 | #endif |
c80c5570 PP |
2923 | #ifdef SSL_OP_NO_COMPRESSION |
2924 | { US"no_compression", SSL_OP_NO_COMPRESSION }, | |
2925 | #endif | |
77bb000f | 2926 | #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |
73a46702 | 2927 | { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, |
77bb000f | 2928 | #endif |
c0c7b2da PP |
2929 | #ifdef SSL_OP_NO_SSLv2 |
2930 | { US"no_sslv2", SSL_OP_NO_SSLv2 }, | |
2931 | #endif | |
2932 | #ifdef SSL_OP_NO_SSLv3 | |
2933 | { US"no_sslv3", SSL_OP_NO_SSLv3 }, | |
2934 | #endif | |
2935 | #ifdef SSL_OP_NO_TICKET | |
2936 | { US"no_ticket", SSL_OP_NO_TICKET }, | |
2937 | #endif | |
2938 | #ifdef SSL_OP_NO_TLSv1 | |
2939 | { US"no_tlsv1", SSL_OP_NO_TLSv1 }, | |
2940 | #endif | |
c80c5570 PP |
2941 | #ifdef SSL_OP_NO_TLSv1_1 |
2942 | #if SSL_OP_NO_TLSv1_1 == 0x00000400L | |
2943 | /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */ | |
2944 | #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring | |
2945 | #else | |
2946 | { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 }, | |
2947 | #endif | |
2948 | #endif | |
2949 | #ifdef SSL_OP_NO_TLSv1_2 | |
2950 | { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 }, | |
2951 | #endif | |
e2fbf4a2 PP |
2952 | #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG |
2953 | { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG }, | |
2954 | #endif | |
77bb000f | 2955 | #ifdef SSL_OP_SINGLE_DH_USE |
73a46702 | 2956 | { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, |
77bb000f PP |
2957 | #endif |
2958 | #ifdef SSL_OP_SINGLE_ECDH_USE | |
73a46702 | 2959 | { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, |
77bb000f PP |
2960 | #endif |
2961 | #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG | |
73a46702 | 2962 | { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, |
77bb000f PP |
2963 | #endif |
2964 | #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG | |
73a46702 | 2965 | { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, |
77bb000f PP |
2966 | #endif |
2967 | #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG | |
73a46702 | 2968 | { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, |
77bb000f PP |
2969 | #endif |
2970 | #ifdef SSL_OP_TLS_D5_BUG | |
73a46702 | 2971 | { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, |
77bb000f PP |
2972 | #endif |
2973 | #ifdef SSL_OP_TLS_ROLLBACK_BUG | |
73a46702 | 2974 | { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, |
77bb000f PP |
2975 | #endif |
2976 | }; | |
2977 | static int exim_openssl_options_size = | |
2978 | sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option); | |
2979 | ||
c80c5570 | 2980 | |
77bb000f PP |
2981 | static BOOL |
2982 | tls_openssl_one_option_parse(uschar *name, long *value) | |
2983 | { | |
2984 | int first = 0; | |
2985 | int last = exim_openssl_options_size; | |
2986 | while (last > first) | |
2987 | { | |
2988 | int middle = (first + last)/2; | |
2989 | int c = Ustrcmp(name, exim_openssl_options[middle].name); | |
2990 | if (c == 0) | |
2991 | { | |
2992 | *value = exim_openssl_options[middle].value; | |
2993 | return TRUE; | |
2994 | } | |
2995 | else if (c > 0) | |
2996 | first = middle + 1; | |
2997 | else | |
2998 | last = middle; | |
2999 | } | |
3000 | return FALSE; | |
3001 | } | |
3002 | ||
3003 | ||
3004 | ||
3005 | ||
3006 | /************************************************* | |
3007 | * OpenSSL option parsing logic * | |
3008 | *************************************************/ | |
3009 | ||
3010 | /* OpenSSL has a number of compatibility options which an administrator might | |
3011 | reasonably wish to set. Interpret a list similarly to decode_bits(), so that | |
3012 | we look like log_selector. | |
3013 | ||
3014 | Arguments: | |
3015 | option_spec the administrator-supplied string of options | |
3016 | results ptr to long storage for the options bitmap | |
3017 | Returns success or failure | |
3018 | */ | |
3019 | ||
3020 | BOOL | |
3021 | tls_openssl_options_parse(uschar *option_spec, long *results) | |
3022 | { | |
3023 | long result, item; | |
3024 | uschar *s, *end; | |
3025 | uschar keep_c; | |
3026 | BOOL adding, item_parsed; | |
3027 | ||
7006ee24 | 3028 | result = SSL_OP_NO_TICKET; |
b1770b6e | 3029 | /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed |
da3ad30d | 3030 | * from default because it increases BEAST susceptibility. */ |
f0f5a555 PP |
3031 | #ifdef SSL_OP_NO_SSLv2 |
3032 | result |= SSL_OP_NO_SSLv2; | |
3033 | #endif | |
a57b6200 JH |
3034 | #ifdef SSL_OP_SINGLE_DH_USE |
3035 | result |= SSL_OP_SINGLE_DH_USE; | |
3036 | #endif | |
77bb000f | 3037 | |
7006ee24 | 3038 | if (!option_spec) |
77bb000f PP |
3039 | { |
3040 | *results = result; | |
3041 | return TRUE; | |
3042 | } | |
3043 | ||
3044 | for (s=option_spec; *s != '\0'; /**/) | |
3045 | { | |
3046 | while (isspace(*s)) ++s; | |
3047 | if (*s == '\0') | |
3048 | break; | |
3049 | if (*s != '+' && *s != '-') | |
3050 | { | |
3051 | DEBUG(D_tls) debug_printf("malformed openssl option setting: " | |
0e944a0d | 3052 | "+ or - expected but found \"%s\"\n", s); |
77bb000f PP |
3053 | return FALSE; |
3054 | } | |
3055 | adding = *s++ == '+'; | |
3056 | for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; | |
3057 | keep_c = *end; | |
3058 | *end = '\0'; | |
3059 | item_parsed = tls_openssl_one_option_parse(s, &item); | |
96f5fe4c | 3060 | *end = keep_c; |
77bb000f PP |
3061 | if (!item_parsed) |
3062 | { | |
0e944a0d | 3063 | DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); |
77bb000f PP |
3064 | return FALSE; |
3065 | } | |
3066 | DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n", | |
3067 | adding ? "adding" : "removing", result, item, s); | |
3068 | if (adding) | |
3069 | result |= item; | |
3070 | else | |
3071 | result &= ~item; | |
77bb000f PP |
3072 | s = end; |
3073 | } | |
3074 | ||
3075 | *results = result; | |
3076 | return TRUE; | |
3077 | } | |
3078 | ||
9d1c15ef JH |
3079 | /* vi: aw ai sw=2 |
3080 | */ | |
059ec3d9 | 3081 | /* End of tls-openssl.c */ |