Commit | Line | Data |
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059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
5a66c31b | 5 | /* Copyright (c) University of Cambridge 1995 - 2014 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
f5d78688 JH |
8 | /* Portions Copyright (c) The OpenSSL Project 1999 */ |
9 | ||
059ec3d9 PH |
10 | /* This module provides the TLS (aka SSL) support for Exim using the OpenSSL |
11 | library. It is #included into the tls.c file when that library is used. The | |
12 | code herein is based on a patch that was originally contributed by Steve | |
13 | Haslam. It was adapted from stunnel, a GPL program by Michal Trojnara. | |
14 | ||
15 | No cryptographic code is included in Exim. All this module does is to call | |
16 | functions from the OpenSSL library. */ | |
17 | ||
18 | ||
19 | /* Heading stuff */ | |
20 | ||
21 | #include <openssl/lhash.h> | |
22 | #include <openssl/ssl.h> | |
23 | #include <openssl/err.h> | |
24 | #include <openssl/rand.h> | |
f2de3a33 | 25 | #ifndef DISABLE_OCSP |
e51c7be2 | 26 | # include <openssl/ocsp.h> |
3f7eeb86 PP |
27 | #endif |
28 | ||
f2de3a33 JH |
29 | #ifndef DISABLE_OCSP |
30 | # define EXIM_OCSP_SKEW_SECONDS (300L) | |
31 | # define EXIM_OCSP_MAX_AGE (-1L) | |
3f7eeb86 | 32 | #endif |
059ec3d9 | 33 | |
3bcbbbe2 | 34 | #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT) |
e51c7be2 | 35 | # define EXIM_HAVE_OPENSSL_TLSEXT |
3bcbbbe2 PP |
36 | #endif |
37 | ||
67791ce4 JH |
38 | #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP) |
39 | # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile" | |
40 | # define DISABLE_OCSP | |
41 | #endif | |
42 | ||
059ec3d9 PH |
43 | /* Structure for collecting random data for seeding. */ |
44 | ||
45 | typedef struct randstuff { | |
9e3331ea TK |
46 | struct timeval tv; |
47 | pid_t p; | |
059ec3d9 PH |
48 | } randstuff; |
49 | ||
50 | /* Local static variables */ | |
51 | ||
a2ff477a JH |
52 | static BOOL client_verify_callback_called = FALSE; |
53 | static BOOL server_verify_callback_called = FALSE; | |
059ec3d9 PH |
54 | static const uschar *sid_ctx = US"exim"; |
55 | ||
d4f09789 PP |
56 | /* We have three different contexts to care about. |
57 | ||
58 | Simple case: client, `client_ctx` | |
59 | As a client, we can be doing a callout or cut-through delivery while receiving | |
60 | a message. So we have a client context, which should have options initialised | |
61 | from the SMTP Transport. | |
62 | ||
63 | Server: | |
64 | There are two cases: with and without ServerNameIndication from the client. | |
65 | Given TLS SNI, we can be using different keys, certs and various other | |
66 | configuration settings, because they're re-expanded with $tls_sni set. This | |
67 | allows vhosting with TLS. This SNI is sent in the handshake. | |
68 | A client might not send SNI, so we need a fallback, and an initial setup too. | |
69 | So as a server, we start out using `server_ctx`. | |
70 | If SNI is sent by the client, then we as server, mid-negotiation, try to clone | |
71 | `server_sni` from `server_ctx` and then initialise settings by re-expanding | |
72 | configuration. | |
73 | */ | |
74 | ||
817d9f57 JH |
75 | static SSL_CTX *client_ctx = NULL; |
76 | static SSL_CTX *server_ctx = NULL; | |
77 | static SSL *client_ssl = NULL; | |
78 | static SSL *server_ssl = NULL; | |
389ca47a | 79 | |
35731706 | 80 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 | 81 | static SSL_CTX *server_sni = NULL; |
35731706 | 82 | #endif |
059ec3d9 PH |
83 | |
84 | static char ssl_errstring[256]; | |
85 | ||
86 | static int ssl_session_timeout = 200; | |
a2ff477a JH |
87 | static BOOL client_verify_optional = FALSE; |
88 | static BOOL server_verify_optional = FALSE; | |
059ec3d9 | 89 | |
f5d78688 | 90 | static BOOL reexpand_tls_files_for_sni = FALSE; |
059ec3d9 PH |
91 | |
92 | ||
7be682ca PP |
93 | typedef struct tls_ext_ctx_cb { |
94 | uschar *certificate; | |
95 | uschar *privatekey; | |
f2de3a33 | 96 | #ifndef DISABLE_OCSP |
f5d78688 JH |
97 | BOOL is_server; |
98 | union { | |
99 | struct { | |
100 | uschar *file; | |
101 | uschar *file_expanded; | |
102 | OCSP_RESPONSE *response; | |
103 | } server; | |
104 | struct { | |
44662487 JH |
105 | X509_STORE *verify_store; /* non-null if status requested */ |
106 | BOOL verify_required; | |
f5d78688 JH |
107 | } client; |
108 | } u_ocsp; | |
3f7eeb86 | 109 | #endif |
7be682ca PP |
110 | uschar *dhparam; |
111 | /* these are cached from first expand */ | |
112 | uschar *server_cipher_list; | |
113 | /* only passed down to tls_error: */ | |
114 | host_item *host; | |
e51c7be2 JH |
115 | |
116 | #ifdef EXPERIMENTAL_CERTNAMES | |
117 | uschar * verify_cert_hostnames; | |
118 | #endif | |
7be682ca PP |
119 | } tls_ext_ctx_cb; |
120 | ||
121 | /* should figure out a cleanup of API to handle state preserved per | |
122 | implementation, for various reasons, which can be void * in the APIs. | |
123 | For now, we hack around it. */ | |
817d9f57 JH |
124 | tls_ext_ctx_cb *client_static_cbinfo = NULL; |
125 | tls_ext_ctx_cb *server_static_cbinfo = NULL; | |
7be682ca PP |
126 | |
127 | static int | |
983207c1 JH |
128 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
129 | int (*cert_vfy_cb)(int, X509_STORE_CTX *) ); | |
059ec3d9 | 130 | |
3f7eeb86 | 131 | /* Callbacks */ |
3bcbbbe2 | 132 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
3f7eeb86 | 133 | static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg); |
3bcbbbe2 | 134 | #endif |
f2de3a33 | 135 | #ifndef DISABLE_OCSP |
f5d78688 | 136 | static int tls_server_stapling_cb(SSL *s, void *arg); |
3f7eeb86 PP |
137 | #endif |
138 | ||
059ec3d9 PH |
139 | |
140 | /************************************************* | |
141 | * Handle TLS error * | |
142 | *************************************************/ | |
143 | ||
144 | /* Called from lots of places when errors occur before actually starting to do | |
145 | the TLS handshake, that is, while the session is still in clear. Always returns | |
146 | DEFER for a server and FAIL for a client so that most calls can use "return | |
147 | tls_error(...)" to do this processing and then give an appropriate return. A | |
148 | single function is used for both server and client, because it is called from | |
149 | some shared functions. | |
150 | ||
151 | Argument: | |
152 | prefix text to include in the logged error | |
153 | host NULL if setting up a server; | |
154 | the connected host if setting up a client | |
7199e1ee | 155 | msg error message or NULL if we should ask OpenSSL |
059ec3d9 PH |
156 | |
157 | Returns: OK/DEFER/FAIL | |
158 | */ | |
159 | ||
160 | static int | |
7199e1ee | 161 | tls_error(uschar *prefix, host_item *host, uschar *msg) |
059ec3d9 | 162 | { |
7199e1ee TF |
163 | if (msg == NULL) |
164 | { | |
165 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
5ca6d115 | 166 | msg = (uschar *)ssl_errstring; |
7199e1ee TF |
167 | } |
168 | ||
059ec3d9 PH |
169 | if (host == NULL) |
170 | { | |
7199e1ee | 171 | uschar *conn_info = smtp_get_connection_info(); |
5ca6d115 | 172 | if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) |
7199e1ee TF |
173 | conn_info += 5; |
174 | log_write(0, LOG_MAIN, "TLS error on %s (%s): %s", | |
175 | conn_info, prefix, msg); | |
059ec3d9 PH |
176 | return DEFER; |
177 | } | |
178 | else | |
179 | { | |
180 | log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s): %s", | |
7199e1ee | 181 | host->name, host->address, prefix, msg); |
059ec3d9 PH |
182 | return FAIL; |
183 | } | |
184 | } | |
185 | ||
186 | ||
187 | ||
188 | /************************************************* | |
189 | * Callback to generate RSA key * | |
190 | *************************************************/ | |
191 | ||
192 | /* | |
193 | Arguments: | |
194 | s SSL connection | |
195 | export not used | |
196 | keylength keylength | |
197 | ||
198 | Returns: pointer to generated key | |
199 | */ | |
200 | ||
201 | static RSA * | |
202 | rsa_callback(SSL *s, int export, int keylength) | |
203 | { | |
204 | RSA *rsa_key; | |
205 | export = export; /* Shut picky compilers up */ | |
206 | DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength); | |
207 | rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL); | |
208 | if (rsa_key == NULL) | |
209 | { | |
210 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
211 | log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s", | |
212 | ssl_errstring); | |
213 | return NULL; | |
214 | } | |
215 | return rsa_key; | |
216 | } | |
217 | ||
218 | ||
219 | ||
f5d78688 | 220 | /* Extreme debug |
f2de3a33 | 221 | #ifndef DISABLE_OCSP |
f5d78688 JH |
222 | void |
223 | x509_store_dump_cert_s_names(X509_STORE * store) | |
224 | { | |
225 | STACK_OF(X509_OBJECT) * roots= store->objs; | |
226 | int i; | |
227 | static uschar name[256]; | |
228 | ||
229 | for(i= 0; i<sk_X509_OBJECT_num(roots); i++) | |
230 | { | |
231 | X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i); | |
232 | if(tmp_obj->type == X509_LU_X509) | |
233 | { | |
234 | X509 * current_cert= tmp_obj->data.x509; | |
235 | X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name)); | |
236 | debug_printf(" %s\n", name); | |
237 | } | |
238 | } | |
239 | } | |
240 | #endif | |
241 | */ | |
242 | ||
059ec3d9 PH |
243 | |
244 | /************************************************* | |
245 | * Callback for verification * | |
246 | *************************************************/ | |
247 | ||
248 | /* The SSL library does certificate verification if set up to do so. This | |
249 | callback has the current yes/no state is in "state". If verification succeeded, | |
250 | we set up the tls_peerdn string. If verification failed, what happens depends | |
251 | on whether the client is required to present a verifiable certificate or not. | |
252 | ||
253 | If verification is optional, we change the state to yes, but still log the | |
254 | verification error. For some reason (it really would help to have proper | |
255 | documentation of OpenSSL), this callback function then gets called again, this | |
256 | time with state = 1. In fact, that's useful, because we can set up the peerdn | |
257 | value, but we must take care not to set the private verified flag on the second | |
258 | time through. | |
259 | ||
260 | Note: this function is not called if the client fails to present a certificate | |
261 | when asked. We get here only if a certificate has been received. Handling of | |
262 | optional verification for this case is done when requesting SSL to verify, by | |
263 | setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case. | |
264 | ||
265 | Arguments: | |
266 | state current yes/no state as 1/0 | |
267 | x509ctx certificate information. | |
a2ff477a | 268 | client TRUE for client startup, FALSE for server startup |
059ec3d9 PH |
269 | |
270 | Returns: 1 if verified, 0 if not | |
271 | */ | |
272 | ||
273 | static int | |
421aff85 JH |
274 | verify_callback(int state, X509_STORE_CTX *x509ctx, |
275 | tls_support *tlsp, BOOL *calledp, BOOL *optionalp) | |
059ec3d9 | 276 | { |
421aff85 | 277 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); |
059ec3d9 PH |
278 | static uschar txt[256]; |
279 | ||
e51c7be2 | 280 | X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt)); |
059ec3d9 PH |
281 | |
282 | if (state == 0) | |
283 | { | |
284 | log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s", | |
421aff85 JH |
285 | X509_STORE_CTX_get_error_depth(x509ctx), |
286 | X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), | |
059ec3d9 | 287 | txt); |
a2ff477a JH |
288 | tlsp->certificate_verified = FALSE; |
289 | *calledp = TRUE; | |
9d1c15ef JH |
290 | if (!*optionalp) |
291 | { | |
421aff85 | 292 | tlsp->peercert = X509_dup(cert); |
9d1c15ef JH |
293 | return 0; /* reject */ |
294 | } | |
059ec3d9 PH |
295 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
296 | "tls_try_verify_hosts)\n"); | |
059ec3d9 PH |
297 | } |
298 | ||
421aff85 | 299 | else if (X509_STORE_CTX_get_error_depth(x509ctx) != 0) |
059ec3d9 | 300 | { |
93dcb1c2 | 301 | DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", |
421aff85 | 302 | X509_STORE_CTX_get_error_depth(x509ctx), txt); |
f2de3a33 | 303 | #ifndef DISABLE_OCSP |
f5d78688 JH |
304 | if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store) |
305 | { /* client, wanting stapling */ | |
306 | /* Add the server cert's signing chain as the one | |
307 | for the verification of the OCSP stapled information. */ | |
308 | ||
309 | if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, | |
421aff85 | 310 | cert)) |
f5d78688 JH |
311 | ERR_clear_error(); |
312 | } | |
313 | #endif | |
059ec3d9 PH |
314 | } |
315 | else | |
316 | { | |
e51c7be2 JH |
317 | #ifdef EXPERIMENTAL_CERTNAMES |
318 | uschar * verify_cert_hostnames; | |
319 | #endif | |
320 | ||
a2ff477a | 321 | tlsp->peerdn = txt; |
421aff85 | 322 | tlsp->peercert = X509_dup(cert); |
e51c7be2 JH |
323 | |
324 | #ifdef EXPERIMENTAL_CERTNAMES | |
325 | if ( tlsp == &tls_out | |
326 | && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames))) | |
327 | /* client, wanting hostname check */ | |
328 | ||
329 | # if OPENSSL_VERSION_NUMBER >= 0x010100000L || OPENSSL_VERSION_NUMBER >= 0x010002000L | |
d8e7834a JH |
330 | # ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
331 | # define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0 | |
332 | # endif | |
e51c7be2 JH |
333 | { |
334 | int sep = 0; | |
335 | uschar * list = verify_cert_hostnames; | |
336 | uschar * name; | |
d8e7834a JH |
337 | int rc; |
338 | while ((name = string_nextinlist(&list, &sep, NULL, 0))) | |
339 | if ((rc = X509_check_host(cert, name, 0, | |
340 | X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS))) | |
341 | { | |
342 | if (rc < 0) | |
343 | { | |
344 | log_write(0, LOG_MAIN, "SSL verify error: internal error\n"); | |
345 | name = NULL; | |
346 | } | |
e51c7be2 | 347 | break; |
d8e7834a | 348 | } |
e51c7be2 JH |
349 | if (!name) |
350 | { | |
351 | log_write(0, LOG_MAIN, | |
352 | "SSL verify error: certificate name mismatch: \"%s\"\n", txt); | |
353 | return 0; /* reject */ | |
354 | } | |
355 | } | |
356 | # else | |
357 | if (!tls_is_name_for_cert(verify_cert_hostnames, cert)) | |
358 | { | |
359 | log_write(0, LOG_MAIN, | |
360 | "SSL verify error: certificate name mismatch: \"%s\"\n", txt); | |
361 | return 0; /* reject */ | |
362 | } | |
363 | # endif | |
e5cccda9 | 364 | #endif /*EXPERIMENTAL_CERTNAMES*/ |
e51c7be2 | 365 | |
93dcb1c2 JH |
366 | DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n", |
367 | *calledp ? "" : " authenticated", txt); | |
368 | if (!*calledp) tlsp->certificate_verified = TRUE; | |
369 | *calledp = TRUE; | |
059ec3d9 PH |
370 | } |
371 | ||
059ec3d9 PH |
372 | return 1; /* accept */ |
373 | } | |
374 | ||
a2ff477a JH |
375 | static int |
376 | verify_callback_client(int state, X509_STORE_CTX *x509ctx) | |
377 | { | |
f5d78688 | 378 | return verify_callback(state, x509ctx, &tls_out, &client_verify_callback_called, &client_verify_optional); |
a2ff477a JH |
379 | } |
380 | ||
381 | static int | |
382 | verify_callback_server(int state, X509_STORE_CTX *x509ctx) | |
383 | { | |
f5d78688 | 384 | return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, &server_verify_optional); |
a2ff477a JH |
385 | } |
386 | ||
059ec3d9 | 387 | |
e5cccda9 | 388 | #ifdef EXPERIMENTAL_DANE |
53a7196b | 389 | |
e5cccda9 JH |
390 | /* This gets called *by* the dane library verify callback, which interposes |
391 | itself. | |
392 | */ | |
393 | static int | |
394 | verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx) | |
395 | { | |
396 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); | |
397 | static uschar txt[256]; | |
398 | ||
399 | X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt)); | |
400 | ||
401 | DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s\n", txt); | |
402 | tls_out.peerdn = txt; | |
403 | tls_out.peercert = X509_dup(cert); | |
404 | ||
405 | if (state == 1) | |
53a7196b | 406 | tls_out.dane_verified = |
e5cccda9 JH |
407 | tls_out.certificate_verified = TRUE; |
408 | return 1; | |
409 | } | |
53a7196b JH |
410 | |
411 | #endif /*EXPERIMENTAL_DANE*/ | |
e5cccda9 | 412 | |
059ec3d9 PH |
413 | |
414 | /************************************************* | |
415 | * Information callback * | |
416 | *************************************************/ | |
417 | ||
418 | /* The SSL library functions call this from time to time to indicate what they | |
7be682ca PP |
419 | are doing. We copy the string to the debugging output when TLS debugging has |
420 | been requested. | |
059ec3d9 PH |
421 | |
422 | Arguments: | |
423 | s the SSL connection | |
424 | where | |
425 | ret | |
426 | ||
427 | Returns: nothing | |
428 | */ | |
429 | ||
430 | static void | |
431 | info_callback(SSL *s, int where, int ret) | |
432 | { | |
433 | where = where; | |
434 | ret = ret; | |
435 | DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s)); | |
436 | } | |
437 | ||
438 | ||
439 | ||
440 | /************************************************* | |
441 | * Initialize for DH * | |
442 | *************************************************/ | |
443 | ||
444 | /* If dhparam is set, expand it, and load up the parameters for DH encryption. | |
445 | ||
446 | Arguments: | |
a799883d | 447 | dhparam DH parameter file or fixed parameter identity string |
7199e1ee | 448 | host connected host, if client; NULL if server |
059ec3d9 PH |
449 | |
450 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
451 | */ | |
452 | ||
453 | static BOOL | |
a799883d | 454 | init_dh(SSL_CTX *sctx, uschar *dhparam, host_item *host) |
059ec3d9 | 455 | { |
059ec3d9 PH |
456 | BIO *bio; |
457 | DH *dh; | |
458 | uschar *dhexpanded; | |
a799883d | 459 | const char *pem; |
059ec3d9 PH |
460 | |
461 | if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded)) | |
462 | return FALSE; | |
463 | ||
0df4ab80 | 464 | if (!dhexpanded || !*dhexpanded) |
a799883d | 465 | bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1); |
a799883d | 466 | else if (dhexpanded[0] == '/') |
059ec3d9 | 467 | { |
0df4ab80 | 468 | if (!(bio = BIO_new_file(CS dhexpanded, "r"))) |
059ec3d9 | 469 | { |
7199e1ee | 470 | tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), |
a799883d PP |
471 | host, US strerror(errno)); |
472 | return FALSE; | |
059ec3d9 | 473 | } |
a799883d PP |
474 | } |
475 | else | |
476 | { | |
477 | if (Ustrcmp(dhexpanded, "none") == 0) | |
059ec3d9 | 478 | { |
a799883d PP |
479 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); |
480 | return TRUE; | |
059ec3d9 | 481 | } |
a799883d | 482 | |
0df4ab80 | 483 | if (!(pem = std_dh_prime_named(dhexpanded))) |
a799883d PP |
484 | { |
485 | tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded), | |
486 | host, US strerror(errno)); | |
487 | return FALSE; | |
488 | } | |
489 | bio = BIO_new_mem_buf(CS pem, -1); | |
490 | } | |
491 | ||
0df4ab80 | 492 | if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL))) |
a799883d | 493 | { |
059ec3d9 | 494 | BIO_free(bio); |
a799883d PP |
495 | tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded), |
496 | host, NULL); | |
497 | return FALSE; | |
498 | } | |
499 | ||
500 | /* Even if it is larger, we silently return success rather than cause things | |
501 | * to fail out, so that a too-large DH will not knock out all TLS; it's a | |
502 | * debatable choice. */ | |
503 | if ((8*DH_size(dh)) > tls_dh_max_bits) | |
504 | { | |
505 | DEBUG(D_tls) | |
506 | debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d", | |
507 | 8*DH_size(dh), tls_dh_max_bits); | |
508 | } | |
509 | else | |
510 | { | |
511 | SSL_CTX_set_tmp_dh(sctx, dh); | |
512 | DEBUG(D_tls) | |
513 | debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n", | |
514 | dhexpanded ? dhexpanded : US"default", 8*DH_size(dh)); | |
059ec3d9 PH |
515 | } |
516 | ||
a799883d PP |
517 | DH_free(dh); |
518 | BIO_free(bio); | |
519 | ||
520 | return TRUE; | |
059ec3d9 PH |
521 | } |
522 | ||
523 | ||
524 | ||
525 | ||
f2de3a33 | 526 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
527 | /************************************************* |
528 | * Load OCSP information into state * | |
529 | *************************************************/ | |
530 | ||
f5d78688 | 531 | /* Called to load the server OCSP response from the given file into memory, once |
3f7eeb86 PP |
532 | caller has determined this is needed. Checks validity. Debugs a message |
533 | if invalid. | |
534 | ||
535 | ASSUMES: single response, for single cert. | |
536 | ||
537 | Arguments: | |
538 | sctx the SSL_CTX* to update | |
539 | cbinfo various parts of session state | |
540 | expanded the filename putatively holding an OCSP response | |
541 | ||
542 | */ | |
543 | ||
544 | static void | |
f5d78688 | 545 | ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded) |
3f7eeb86 PP |
546 | { |
547 | BIO *bio; | |
548 | OCSP_RESPONSE *resp; | |
549 | OCSP_BASICRESP *basic_response; | |
550 | OCSP_SINGLERESP *single_response; | |
551 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
552 | X509_STORE *store; | |
553 | unsigned long verify_flags; | |
554 | int status, reason, i; | |
555 | ||
f5d78688 JH |
556 | cbinfo->u_ocsp.server.file_expanded = string_copy(expanded); |
557 | if (cbinfo->u_ocsp.server.response) | |
3f7eeb86 | 558 | { |
f5d78688 JH |
559 | OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response); |
560 | cbinfo->u_ocsp.server.response = NULL; | |
3f7eeb86 PP |
561 | } |
562 | ||
f5d78688 | 563 | bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb"); |
3f7eeb86 PP |
564 | if (!bio) |
565 | { | |
566 | DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", | |
f5d78688 | 567 | cbinfo->u_ocsp.server.file_expanded); |
3f7eeb86 PP |
568 | return; |
569 | } | |
570 | ||
571 | resp = d2i_OCSP_RESPONSE_bio(bio, NULL); | |
572 | BIO_free(bio); | |
573 | if (!resp) | |
574 | { | |
575 | DEBUG(D_tls) debug_printf("Error reading OCSP response.\n"); | |
576 | return; | |
577 | } | |
578 | ||
579 | status = OCSP_response_status(resp); | |
580 | if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) | |
581 | { | |
582 | DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", | |
583 | OCSP_response_status_str(status), status); | |
f5d78688 | 584 | goto bad; |
3f7eeb86 PP |
585 | } |
586 | ||
587 | basic_response = OCSP_response_get1_basic(resp); | |
588 | if (!basic_response) | |
589 | { | |
590 | DEBUG(D_tls) | |
591 | debug_printf("OCSP response parse error: unable to extract basic response.\n"); | |
f5d78688 | 592 | goto bad; |
3f7eeb86 PP |
593 | } |
594 | ||
595 | store = SSL_CTX_get_cert_store(sctx); | |
596 | verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ | |
597 | ||
598 | /* May need to expose ability to adjust those flags? | |
599 | OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT | |
600 | OCSP_TRUSTOTHER OCSP_NOINTERN */ | |
601 | ||
602 | i = OCSP_basic_verify(basic_response, NULL, store, verify_flags); | |
603 | if (i <= 0) | |
604 | { | |
605 | DEBUG(D_tls) { | |
606 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
607 | debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); | |
f5d78688 JH |
608 | } |
609 | goto bad; | |
3f7eeb86 PP |
610 | } |
611 | ||
612 | /* Here's the simplifying assumption: there's only one response, for the | |
613 | one certificate we use, and nothing for anything else in a chain. If this | |
614 | proves false, we need to extract a cert id from our issued cert | |
615 | (tls_certificate) and use that for OCSP_resp_find_status() (which finds the | |
616 | right cert in the stack and then calls OCSP_single_get0_status()). | |
617 | ||
618 | I'm hoping to avoid reworking a bunch more of how we handle state here. */ | |
619 | single_response = OCSP_resp_get0(basic_response, 0); | |
620 | if (!single_response) | |
621 | { | |
622 | DEBUG(D_tls) | |
623 | debug_printf("Unable to get first response from OCSP basic response.\n"); | |
f5d78688 | 624 | goto bad; |
3f7eeb86 PP |
625 | } |
626 | ||
627 | status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd); | |
f5d78688 | 628 | if (status != V_OCSP_CERTSTATUS_GOOD) |
3f7eeb86 | 629 | { |
f5d78688 JH |
630 | DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n", |
631 | OCSP_cert_status_str(status), status, | |
632 | OCSP_crl_reason_str(reason), reason); | |
633 | goto bad; | |
3f7eeb86 PP |
634 | } |
635 | ||
636 | if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
637 | { | |
638 | DEBUG(D_tls) debug_printf("OCSP status invalid times.\n"); | |
f5d78688 | 639 | goto bad; |
3f7eeb86 PP |
640 | } |
641 | ||
f5d78688 | 642 | supply_response: |
018058b2 | 643 | cbinfo->u_ocsp.server.response = resp; |
f5d78688 JH |
644 | return; |
645 | ||
646 | bad: | |
018058b2 JH |
647 | if (running_in_test_harness) |
648 | { | |
649 | extern char ** environ; | |
650 | uschar ** p; | |
651 | for (p = USS environ; *p != NULL; p++) | |
652 | if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) | |
653 | { | |
654 | DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n"); | |
655 | goto supply_response; | |
656 | } | |
657 | } | |
f5d78688 | 658 | return; |
3f7eeb86 | 659 | } |
f2de3a33 | 660 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
661 | |
662 | ||
663 | ||
664 | ||
7be682ca PP |
665 | /************************************************* |
666 | * Expand key and cert file specs * | |
667 | *************************************************/ | |
668 | ||
f5d78688 | 669 | /* Called once during tls_init and possibly again during TLS setup, for a |
7be682ca PP |
670 | new context, if Server Name Indication was used and tls_sni was seen in |
671 | the certificate string. | |
672 | ||
673 | Arguments: | |
674 | sctx the SSL_CTX* to update | |
675 | cbinfo various parts of session state | |
676 | ||
677 | Returns: OK/DEFER/FAIL | |
678 | */ | |
679 | ||
680 | static int | |
3f7eeb86 | 681 | tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo) |
7be682ca PP |
682 | { |
683 | uschar *expanded; | |
684 | ||
685 | if (cbinfo->certificate == NULL) | |
686 | return OK; | |
687 | ||
d9b2312b JH |
688 | if (Ustrstr(cbinfo->certificate, US"tls_sni") || |
689 | Ustrstr(cbinfo->certificate, US"tls_in_sni") || | |
690 | Ustrstr(cbinfo->certificate, US"tls_out_sni") | |
691 | ) | |
7be682ca PP |
692 | reexpand_tls_files_for_sni = TRUE; |
693 | ||
694 | if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded)) | |
695 | return DEFER; | |
696 | ||
697 | if (expanded != NULL) | |
698 | { | |
699 | DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); | |
700 | if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded)) | |
701 | return tls_error(string_sprintf( | |
702 | "SSL_CTX_use_certificate_chain_file file=%s", expanded), | |
703 | cbinfo->host, NULL); | |
704 | } | |
705 | ||
706 | if (cbinfo->privatekey != NULL && | |
707 | !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded)) | |
708 | return DEFER; | |
709 | ||
710 | /* If expansion was forced to fail, key_expanded will be NULL. If the result | |
711 | of the expansion is an empty string, ignore it also, and assume the private | |
712 | key is in the same file as the certificate. */ | |
713 | ||
714 | if (expanded != NULL && *expanded != 0) | |
715 | { | |
716 | DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); | |
717 | if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM)) | |
718 | return tls_error(string_sprintf( | |
719 | "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL); | |
720 | } | |
721 | ||
f2de3a33 | 722 | #ifndef DISABLE_OCSP |
f5d78688 | 723 | if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL) |
3f7eeb86 | 724 | { |
f5d78688 | 725 | if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded)) |
3f7eeb86 PP |
726 | return DEFER; |
727 | ||
728 | if (expanded != NULL && *expanded != 0) | |
729 | { | |
730 | DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded); | |
f5d78688 JH |
731 | if (cbinfo->u_ocsp.server.file_expanded && |
732 | (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0)) | |
3f7eeb86 PP |
733 | { |
734 | DEBUG(D_tls) | |
735 | debug_printf("tls_ocsp_file value unchanged, using existing values.\n"); | |
736 | } else { | |
737 | ocsp_load_response(sctx, cbinfo, expanded); | |
738 | } | |
739 | } | |
740 | } | |
741 | #endif | |
742 | ||
7be682ca PP |
743 | return OK; |
744 | } | |
745 | ||
746 | ||
747 | ||
748 | ||
749 | /************************************************* | |
750 | * Callback to handle SNI * | |
751 | *************************************************/ | |
752 | ||
753 | /* Called when acting as server during the TLS session setup if a Server Name | |
754 | Indication extension was sent by the client. | |
755 | ||
756 | API documentation is OpenSSL s_server.c implementation. | |
757 | ||
758 | Arguments: | |
759 | s SSL* of the current session | |
760 | ad unknown (part of OpenSSL API) (unused) | |
761 | arg Callback of "our" registered data | |
762 | ||
763 | Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK} | |
764 | */ | |
765 | ||
3bcbbbe2 | 766 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
7be682ca PP |
767 | static int |
768 | tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg) | |
769 | { | |
770 | const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); | |
3f7eeb86 | 771 | tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; |
7be682ca | 772 | int rc; |
3f0945ff | 773 | int old_pool = store_pool; |
7be682ca PP |
774 | |
775 | if (!servername) | |
776 | return SSL_TLSEXT_ERR_OK; | |
777 | ||
3f0945ff | 778 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername, |
7be682ca PP |
779 | reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)"); |
780 | ||
781 | /* Make the extension value available for expansion */ | |
3f0945ff | 782 | store_pool = POOL_PERM; |
817d9f57 | 783 | tls_in.sni = string_copy(US servername); |
3f0945ff | 784 | store_pool = old_pool; |
7be682ca PP |
785 | |
786 | if (!reexpand_tls_files_for_sni) | |
787 | return SSL_TLSEXT_ERR_OK; | |
788 | ||
789 | /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually; | |
790 | not confident that memcpy wouldn't break some internal reference counting. | |
791 | Especially since there's a references struct member, which would be off. */ | |
792 | ||
0df4ab80 | 793 | if (!(server_sni = SSL_CTX_new(SSLv23_server_method()))) |
7be682ca PP |
794 | { |
795 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
796 | DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring); | |
797 | return SSL_TLSEXT_ERR_NOACK; | |
798 | } | |
799 | ||
800 | /* Not sure how many of these are actually needed, since SSL object | |
801 | already exists. Might even need this selfsame callback, for reneg? */ | |
802 | ||
817d9f57 JH |
803 | SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx)); |
804 | SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx)); | |
805 | SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); | |
806 | SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); | |
807 | SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); | |
808 | SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); | |
7be682ca | 809 | if (cbinfo->server_cipher_list) |
817d9f57 | 810 | SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list); |
f2de3a33 | 811 | #ifndef DISABLE_OCSP |
f5d78688 | 812 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 813 | { |
f5d78688 | 814 | SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb); |
14c7b357 | 815 | SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo); |
3f7eeb86 PP |
816 | } |
817 | #endif | |
7be682ca | 818 | |
983207c1 | 819 | rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server); |
7be682ca PP |
820 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
821 | ||
3f7eeb86 PP |
822 | /* do this after setup_certs, because this can require the certs for verifying |
823 | OCSP information. */ | |
817d9f57 | 824 | rc = tls_expand_session_files(server_sni, cbinfo); |
7be682ca PP |
825 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
826 | ||
0df4ab80 JH |
827 | if (!init_dh(server_sni, cbinfo->dhparam, NULL)) |
828 | return SSL_TLSEXT_ERR_NOACK; | |
a799883d | 829 | |
7be682ca | 830 | DEBUG(D_tls) debug_printf("Switching SSL context.\n"); |
817d9f57 | 831 | SSL_set_SSL_CTX(s, server_sni); |
7be682ca PP |
832 | |
833 | return SSL_TLSEXT_ERR_OK; | |
834 | } | |
3bcbbbe2 | 835 | #endif /* EXIM_HAVE_OPENSSL_TLSEXT */ |
7be682ca PP |
836 | |
837 | ||
838 | ||
839 | ||
f2de3a33 | 840 | #ifndef DISABLE_OCSP |
f5d78688 | 841 | |
3f7eeb86 PP |
842 | /************************************************* |
843 | * Callback to handle OCSP Stapling * | |
844 | *************************************************/ | |
845 | ||
846 | /* Called when acting as server during the TLS session setup if the client | |
847 | requests OCSP information with a Certificate Status Request. | |
848 | ||
849 | Documentation via openssl s_server.c and the Apache patch from the OpenSSL | |
850 | project. | |
851 | ||
852 | */ | |
853 | ||
854 | static int | |
f5d78688 | 855 | tls_server_stapling_cb(SSL *s, void *arg) |
3f7eeb86 PP |
856 | { |
857 | const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; | |
858 | uschar *response_der; | |
859 | int response_der_len; | |
860 | ||
af4a1bca JH |
861 | DEBUG(D_tls) |
862 | debug_printf("Received TLS status request (OCSP stapling); %s response.", | |
f5d78688 JH |
863 | cbinfo->u_ocsp.server.response ? "have" : "lack"); |
864 | ||
44662487 | 865 | tls_in.ocsp = OCSP_NOT_RESP; |
f5d78688 | 866 | if (!cbinfo->u_ocsp.server.response) |
3f7eeb86 PP |
867 | return SSL_TLSEXT_ERR_NOACK; |
868 | ||
869 | response_der = NULL; | |
44662487 JH |
870 | response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response, |
871 | &response_der); | |
3f7eeb86 PP |
872 | if (response_der_len <= 0) |
873 | return SSL_TLSEXT_ERR_NOACK; | |
874 | ||
5e55c7a9 | 875 | SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len); |
44662487 | 876 | tls_in.ocsp = OCSP_VFIED; |
3f7eeb86 PP |
877 | return SSL_TLSEXT_ERR_OK; |
878 | } | |
879 | ||
3f7eeb86 | 880 | |
f5d78688 JH |
881 | static void |
882 | time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time) | |
883 | { | |
884 | BIO_printf(bp, "\t%s: ", str); | |
885 | ASN1_GENERALIZEDTIME_print(bp, time); | |
886 | BIO_puts(bp, "\n"); | |
887 | } | |
888 | ||
889 | static int | |
890 | tls_client_stapling_cb(SSL *s, void *arg) | |
891 | { | |
892 | tls_ext_ctx_cb * cbinfo = arg; | |
893 | const unsigned char * p; | |
894 | int len; | |
895 | OCSP_RESPONSE * rsp; | |
896 | OCSP_BASICRESP * bs; | |
897 | int i; | |
898 | ||
899 | DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):"); | |
900 | len = SSL_get_tlsext_status_ocsp_resp(s, &p); | |
901 | if(!p) | |
902 | { | |
44662487 JH |
903 | /* Expect this when we requested ocsp but got none */ |
904 | if ( cbinfo->u_ocsp.client.verify_required | |
905 | && log_extra_selector & LX_tls_cipher) | |
906 | log_write(0, LOG_MAIN, "Received TLS status callback, null content"); | |
f5d78688 JH |
907 | else |
908 | DEBUG(D_tls) debug_printf(" null\n"); | |
44662487 | 909 | return cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 910 | } |
018058b2 | 911 | |
f5d78688 JH |
912 | if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) |
913 | { | |
018058b2 | 914 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
915 | if (log_extra_selector & LX_tls_cipher) |
916 | log_write(0, LOG_MAIN, "Received TLS status response, parse error"); | |
917 | else | |
918 | DEBUG(D_tls) debug_printf(" parse error\n"); | |
919 | return 0; | |
920 | } | |
921 | ||
922 | if(!(bs = OCSP_response_get1_basic(rsp))) | |
923 | { | |
018058b2 | 924 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
925 | if (log_extra_selector & LX_tls_cipher) |
926 | log_write(0, LOG_MAIN, "Received TLS status response, error parsing response"); | |
927 | else | |
928 | DEBUG(D_tls) debug_printf(" error parsing response\n"); | |
929 | OCSP_RESPONSE_free(rsp); | |
930 | return 0; | |
931 | } | |
932 | ||
933 | /* We'd check the nonce here if we'd put one in the request. */ | |
934 | /* However that would defeat cacheability on the server so we don't. */ | |
935 | ||
f5d78688 JH |
936 | /* This section of code reworked from OpenSSL apps source; |
937 | The OpenSSL Project retains copyright: | |
938 | Copyright (c) 1999 The OpenSSL Project. All rights reserved. | |
939 | */ | |
940 | { | |
941 | BIO * bp = NULL; | |
f5d78688 JH |
942 | int status, reason; |
943 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
944 | ||
945 | DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE); | |
946 | ||
947 | /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */ | |
948 | ||
949 | /* Use the chain that verified the server cert to verify the stapled info */ | |
950 | /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */ | |
951 | ||
44662487 JH |
952 | if ((i = OCSP_basic_verify(bs, NULL, |
953 | cbinfo->u_ocsp.client.verify_store, 0)) <= 0) | |
f5d78688 | 954 | { |
018058b2 | 955 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
956 | BIO_printf(bp, "OCSP response verify failure\n"); |
957 | ERR_print_errors(bp); | |
44662487 | 958 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 JH |
959 | goto out; |
960 | } | |
961 | ||
962 | BIO_printf(bp, "OCSP response well-formed and signed OK\n"); | |
963 | ||
964 | { | |
965 | STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; | |
966 | OCSP_SINGLERESP * single; | |
967 | ||
968 | if (sk_OCSP_SINGLERESP_num(sresp) != 1) | |
969 | { | |
018058b2 | 970 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
971 | log_write(0, LOG_MAIN, "OCSP stapling " |
972 | "with multiple responses not handled"); | |
973 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
f5d78688 JH |
974 | goto out; |
975 | } | |
976 | single = OCSP_resp_get0(bs, 0); | |
44662487 JH |
977 | status = OCSP_single_get0_status(single, &reason, &rev, |
978 | &thisupd, &nextupd); | |
f5d78688 JH |
979 | } |
980 | ||
f5d78688 JH |
981 | DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd); |
982 | DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd); | |
44662487 JH |
983 | if (!OCSP_check_validity(thisupd, nextupd, |
984 | EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
f5d78688 | 985 | { |
018058b2 | 986 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
987 | DEBUG(D_tls) ERR_print_errors(bp); |
988 | log_write(0, LOG_MAIN, "Server OSCP dates invalid"); | |
44662487 | 989 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 990 | } |
44662487 | 991 | else |
f5d78688 | 992 | { |
44662487 JH |
993 | DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n", |
994 | OCSP_cert_status_str(status)); | |
995 | switch(status) | |
996 | { | |
997 | case V_OCSP_CERTSTATUS_GOOD: | |
44662487 | 998 | tls_out.ocsp = OCSP_VFIED; |
018058b2 | 999 | i = 1; |
44662487 JH |
1000 | break; |
1001 | case V_OCSP_CERTSTATUS_REVOKED: | |
018058b2 | 1002 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1003 | log_write(0, LOG_MAIN, "Server certificate revoked%s%s", |
1004 | reason != -1 ? "; reason: " : "", | |
1005 | reason != -1 ? OCSP_crl_reason_str(reason) : ""); | |
1006 | DEBUG(D_tls) time_print(bp, "Revocation Time", rev); | |
1007 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1008 | break; | |
1009 | default: | |
018058b2 | 1010 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1011 | log_write(0, LOG_MAIN, |
1012 | "Server certificate status unknown, in OCSP stapling"); | |
1013 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1014 | break; | |
1015 | } | |
f5d78688 JH |
1016 | } |
1017 | out: | |
1018 | BIO_free(bp); | |
1019 | } | |
1020 | ||
1021 | OCSP_RESPONSE_free(rsp); | |
1022 | return i; | |
1023 | } | |
f2de3a33 | 1024 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
1025 | |
1026 | ||
059ec3d9 PH |
1027 | /************************************************* |
1028 | * Initialize for TLS * | |
1029 | *************************************************/ | |
1030 | ||
e51c7be2 JH |
1031 | /* Called from both server and client code, to do preliminary initialization |
1032 | of the library. We allocate and return a context structure. | |
059ec3d9 PH |
1033 | |
1034 | Arguments: | |
946ecbe0 | 1035 | ctxp returned SSL context |
059ec3d9 PH |
1036 | host connected host, if client; NULL if server |
1037 | dhparam DH parameter file | |
1038 | certificate certificate file | |
1039 | privatekey private key | |
f5d78688 | 1040 | ocsp_file file of stapling info (server); flag for require ocsp (client) |
059ec3d9 | 1041 | addr address if client; NULL if server (for some randomness) |
946ecbe0 | 1042 | cbp place to put allocated callback context |
059ec3d9 PH |
1043 | |
1044 | Returns: OK/DEFER/FAIL | |
1045 | */ | |
1046 | ||
1047 | static int | |
817d9f57 | 1048 | tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate, |
3f7eeb86 | 1049 | uschar *privatekey, |
f2de3a33 | 1050 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1051 | uschar *ocsp_file, |
1052 | #endif | |
817d9f57 | 1053 | address_item *addr, tls_ext_ctx_cb ** cbp) |
059ec3d9 | 1054 | { |
77bb000f | 1055 | long init_options; |
7be682ca | 1056 | int rc; |
77bb000f | 1057 | BOOL okay; |
7be682ca PP |
1058 | tls_ext_ctx_cb *cbinfo; |
1059 | ||
1060 | cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); | |
1061 | cbinfo->certificate = certificate; | |
1062 | cbinfo->privatekey = privatekey; | |
f2de3a33 | 1063 | #ifndef DISABLE_OCSP |
f5d78688 JH |
1064 | if ((cbinfo->is_server = host==NULL)) |
1065 | { | |
1066 | cbinfo->u_ocsp.server.file = ocsp_file; | |
1067 | cbinfo->u_ocsp.server.file_expanded = NULL; | |
1068 | cbinfo->u_ocsp.server.response = NULL; | |
1069 | } | |
1070 | else | |
1071 | cbinfo->u_ocsp.client.verify_store = NULL; | |
3f7eeb86 | 1072 | #endif |
7be682ca | 1073 | cbinfo->dhparam = dhparam; |
0df4ab80 | 1074 | cbinfo->server_cipher_list = NULL; |
7be682ca | 1075 | cbinfo->host = host; |
77bb000f | 1076 | |
059ec3d9 PH |
1077 | SSL_load_error_strings(); /* basic set up */ |
1078 | OpenSSL_add_ssl_algorithms(); | |
1079 | ||
388d6564 | 1080 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) |
77bb000f | 1081 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the |
a0475b69 TK |
1082 | list of available digests. */ |
1083 | EVP_add_digest(EVP_sha256()); | |
cf1ef1a9 | 1084 | #endif |
a0475b69 | 1085 | |
f0f5a555 PP |
1086 | /* Create a context. |
1087 | The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant | |
1088 | negotiation in the different methods; as far as I can tell, the only | |
1089 | *_{server,client}_method which allows negotiation is SSLv23, which exists even | |
1090 | when OpenSSL is built without SSLv2 support. | |
1091 | By disabling with openssl_options, we can let admins re-enable with the | |
1092 | existing knob. */ | |
059ec3d9 | 1093 | |
817d9f57 | 1094 | *ctxp = SSL_CTX_new((host == NULL)? |
059ec3d9 PH |
1095 | SSLv23_server_method() : SSLv23_client_method()); |
1096 | ||
817d9f57 | 1097 | if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL); |
059ec3d9 PH |
1098 | |
1099 | /* It turns out that we need to seed the random number generator this early in | |
1100 | order to get the full complement of ciphers to work. It took me roughly a day | |
1101 | of work to discover this by experiment. | |
1102 | ||
1103 | On systems that have /dev/urandom, SSL may automatically seed itself from | |
1104 | there. Otherwise, we have to make something up as best we can. Double check | |
1105 | afterwards. */ | |
1106 | ||
1107 | if (!RAND_status()) | |
1108 | { | |
1109 | randstuff r; | |
9e3331ea | 1110 | gettimeofday(&r.tv, NULL); |
059ec3d9 PH |
1111 | r.p = getpid(); |
1112 | ||
1113 | RAND_seed((uschar *)(&r), sizeof(r)); | |
1114 | RAND_seed((uschar *)big_buffer, big_buffer_size); | |
1115 | if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr)); | |
1116 | ||
1117 | if (!RAND_status()) | |
7199e1ee | 1118 | return tls_error(US"RAND_status", host, |
5ca6d115 | 1119 | US"unable to seed random number generator"); |
059ec3d9 PH |
1120 | } |
1121 | ||
1122 | /* Set up the information callback, which outputs if debugging is at a suitable | |
1123 | level. */ | |
1124 | ||
817d9f57 | 1125 | SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback); |
059ec3d9 | 1126 | |
c80c5570 | 1127 | /* Automatically re-try reads/writes after renegotiation. */ |
817d9f57 | 1128 | (void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY); |
c80c5570 | 1129 | |
77bb000f PP |
1130 | /* Apply administrator-supplied work-arounds. |
1131 | Historically we applied just one requested option, | |
1132 | SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we | |
1133 | moved to an administrator-controlled list of options to specify and | |
1134 | grandfathered in the first one as the default value for "openssl_options". | |
059ec3d9 | 1135 | |
77bb000f PP |
1136 | No OpenSSL version number checks: the options we accept depend upon the |
1137 | availability of the option value macros from OpenSSL. */ | |
059ec3d9 | 1138 | |
77bb000f PP |
1139 | okay = tls_openssl_options_parse(openssl_options, &init_options); |
1140 | if (!okay) | |
73a46702 | 1141 | return tls_error(US"openssl_options parsing failed", host, NULL); |
77bb000f PP |
1142 | |
1143 | if (init_options) | |
1144 | { | |
1145 | DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); | |
817d9f57 | 1146 | if (!(SSL_CTX_set_options(*ctxp, init_options))) |
77bb000f PP |
1147 | return tls_error(string_sprintf( |
1148 | "SSL_CTX_set_option(%#lx)", init_options), host, NULL); | |
1149 | } | |
1150 | else | |
1151 | DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); | |
059ec3d9 PH |
1152 | |
1153 | /* Initialize with DH parameters if supplied */ | |
1154 | ||
817d9f57 | 1155 | if (!init_dh(*ctxp, dhparam, host)) return DEFER; |
059ec3d9 | 1156 | |
3f7eeb86 | 1157 | /* Set up certificate and key (and perhaps OCSP info) */ |
059ec3d9 | 1158 | |
817d9f57 | 1159 | rc = tls_expand_session_files(*ctxp, cbinfo); |
7be682ca | 1160 | if (rc != OK) return rc; |
c91535f3 | 1161 | |
7be682ca | 1162 | /* If we need to handle SNI, do so */ |
3bcbbbe2 | 1163 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
f5d78688 | 1164 | if (host == NULL) /* server */ |
3f0945ff | 1165 | { |
f2de3a33 | 1166 | # ifndef DISABLE_OCSP |
f5d78688 | 1167 | /* We check u_ocsp.server.file, not server.response, because we care about if |
3f7eeb86 PP |
1168 | the option exists, not what the current expansion might be, as SNI might |
1169 | change the certificate and OCSP file in use between now and the time the | |
1170 | callback is invoked. */ | |
f5d78688 | 1171 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1172 | { |
f5d78688 | 1173 | SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb); |
5e55c7a9 | 1174 | SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo); |
3f7eeb86 | 1175 | } |
f5d78688 | 1176 | # endif |
3f0945ff PP |
1177 | /* We always do this, so that $tls_sni is available even if not used in |
1178 | tls_certificate */ | |
817d9f57 JH |
1179 | SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb); |
1180 | SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo); | |
3f0945ff | 1181 | } |
f2de3a33 | 1182 | # ifndef DISABLE_OCSP |
f5d78688 JH |
1183 | else /* client */ |
1184 | if(ocsp_file) /* wanting stapling */ | |
1185 | { | |
1186 | if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new())) | |
1187 | { | |
1188 | DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n"); | |
1189 | return FAIL; | |
1190 | } | |
1191 | SSL_CTX_set_tlsext_status_cb(*ctxp, tls_client_stapling_cb); | |
1192 | SSL_CTX_set_tlsext_status_arg(*ctxp, cbinfo); | |
1193 | } | |
1194 | # endif | |
7be682ca | 1195 | #endif |
059ec3d9 | 1196 | |
e51c7be2 JH |
1197 | #ifdef EXPERIMENTAL_CERTNAMES |
1198 | cbinfo->verify_cert_hostnames = NULL; | |
1199 | #endif | |
1200 | ||
059ec3d9 PH |
1201 | /* Set up the RSA callback */ |
1202 | ||
817d9f57 | 1203 | SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback); |
059ec3d9 PH |
1204 | |
1205 | /* Finally, set the timeout, and we are done */ | |
1206 | ||
817d9f57 | 1207 | SSL_CTX_set_timeout(*ctxp, ssl_session_timeout); |
059ec3d9 | 1208 | DEBUG(D_tls) debug_printf("Initialized TLS\n"); |
7be682ca | 1209 | |
817d9f57 | 1210 | *cbp = cbinfo; |
7be682ca | 1211 | |
059ec3d9 PH |
1212 | return OK; |
1213 | } | |
1214 | ||
1215 | ||
1216 | ||
1217 | ||
1218 | /************************************************* | |
1219 | * Get name of cipher in use * | |
1220 | *************************************************/ | |
1221 | ||
817d9f57 | 1222 | /* |
059ec3d9 | 1223 | Argument: pointer to an SSL structure for the connection |
817d9f57 JH |
1224 | buffer to use for answer |
1225 | size of buffer | |
1226 | pointer to number of bits for cipher | |
059ec3d9 PH |
1227 | Returns: nothing |
1228 | */ | |
1229 | ||
1230 | static void | |
817d9f57 | 1231 | construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits) |
059ec3d9 | 1232 | { |
57b3a7f5 PP |
1233 | /* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't |
1234 | yet reflect that. It should be a safe change anyway, even 0.9.8 versions have | |
1235 | the accessor functions use const in the prototype. */ | |
1236 | const SSL_CIPHER *c; | |
d9784128 | 1237 | const uschar *ver; |
059ec3d9 | 1238 | |
d9784128 | 1239 | ver = (const uschar *)SSL_get_version(ssl); |
059ec3d9 | 1240 | |
57b3a7f5 | 1241 | c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); |
817d9f57 | 1242 | SSL_CIPHER_get_bits(c, bits); |
059ec3d9 | 1243 | |
817d9f57 JH |
1244 | string_format(cipherbuf, bsize, "%s:%s:%u", ver, |
1245 | SSL_CIPHER_get_name(c), *bits); | |
059ec3d9 PH |
1246 | |
1247 | DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf); | |
1248 | } | |
1249 | ||
1250 | ||
1251 | ||
1252 | ||
1253 | ||
1254 | /************************************************* | |
1255 | * Set up for verifying certificates * | |
1256 | *************************************************/ | |
1257 | ||
1258 | /* Called by both client and server startup | |
1259 | ||
1260 | Arguments: | |
7be682ca | 1261 | sctx SSL_CTX* to initialise |
059ec3d9 PH |
1262 | certs certs file or NULL |
1263 | crl CRL file or NULL | |
1264 | host NULL in a server; the remote host in a client | |
1265 | optional TRUE if called from a server for a host in tls_try_verify_hosts; | |
1266 | otherwise passed as FALSE | |
983207c1 | 1267 | cert_vfy_cb Callback function for certificate verification |
059ec3d9 PH |
1268 | |
1269 | Returns: OK/DEFER/FAIL | |
1270 | */ | |
1271 | ||
1272 | static int | |
983207c1 JH |
1273 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
1274 | int (*cert_vfy_cb)(int, X509_STORE_CTX *) ) | |
059ec3d9 PH |
1275 | { |
1276 | uschar *expcerts, *expcrl; | |
1277 | ||
1278 | if (!expand_check(certs, US"tls_verify_certificates", &expcerts)) | |
1279 | return DEFER; | |
1280 | ||
26e72755 | 1281 | if (expcerts != NULL && *expcerts != '\0') |
059ec3d9 PH |
1282 | { |
1283 | struct stat statbuf; | |
7be682ca | 1284 | if (!SSL_CTX_set_default_verify_paths(sctx)) |
7199e1ee | 1285 | return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL); |
059ec3d9 PH |
1286 | |
1287 | if (Ustat(expcerts, &statbuf) < 0) | |
1288 | { | |
1289 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1290 | "failed to stat %s for certificates", expcerts); | |
1291 | return DEFER; | |
1292 | } | |
1293 | else | |
1294 | { | |
1295 | uschar *file, *dir; | |
1296 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
1297 | { file = NULL; dir = expcerts; } | |
1298 | else | |
1299 | { file = expcerts; dir = NULL; } | |
1300 | ||
1301 | /* If a certificate file is empty, the next function fails with an | |
1302 | unhelpful error message. If we skip it, we get the correct behaviour (no | |
1303 | certificates are recognized, but the error message is still misleading (it | |
1304 | says no certificate was supplied.) But this is better. */ | |
1305 | ||
1306 | if ((file == NULL || statbuf.st_size > 0) && | |
7be682ca | 1307 | !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) |
7199e1ee | 1308 | return tls_error(US"SSL_CTX_load_verify_locations", host, NULL); |
059ec3d9 PH |
1309 | |
1310 | if (file != NULL) | |
1311 | { | |
7be682ca | 1312 | SSL_CTX_set_client_CA_list(sctx, SSL_load_client_CA_file(CS file)); |
059ec3d9 PH |
1313 | } |
1314 | } | |
1315 | ||
1316 | /* Handle a certificate revocation list. */ | |
1317 | ||
1318 | #if OPENSSL_VERSION_NUMBER > 0x00907000L | |
1319 | ||
8b417f2c PH |
1320 | /* This bit of code is now the version supplied by Lars Mainka. (I have |
1321 | * merely reformatted it into the Exim code style.) | |
1322 | ||
1323 | * "From here I changed the code to add support for multiple crl's | |
1324 | * in pem format in one file or to support hashed directory entries in | |
1325 | * pem format instead of a file. This method now uses the library function | |
1326 | * X509_STORE_load_locations to add the CRL location to the SSL context. | |
1327 | * OpenSSL will then handle the verify against CA certs and CRLs by | |
1328 | * itself in the verify callback." */ | |
1329 | ||
059ec3d9 PH |
1330 | if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER; |
1331 | if (expcrl != NULL && *expcrl != 0) | |
1332 | { | |
8b417f2c PH |
1333 | struct stat statbufcrl; |
1334 | if (Ustat(expcrl, &statbufcrl) < 0) | |
1335 | { | |
1336 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1337 | "failed to stat %s for certificates revocation lists", expcrl); | |
1338 | return DEFER; | |
1339 | } | |
1340 | else | |
059ec3d9 | 1341 | { |
8b417f2c PH |
1342 | /* is it a file or directory? */ |
1343 | uschar *file, *dir; | |
7be682ca | 1344 | X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx); |
8b417f2c | 1345 | if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR) |
059ec3d9 | 1346 | { |
8b417f2c PH |
1347 | file = NULL; |
1348 | dir = expcrl; | |
1349 | DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir); | |
059ec3d9 PH |
1350 | } |
1351 | else | |
1352 | { | |
8b417f2c PH |
1353 | file = expcrl; |
1354 | dir = NULL; | |
1355 | DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); | |
059ec3d9 | 1356 | } |
8b417f2c | 1357 | if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) |
7199e1ee | 1358 | return tls_error(US"X509_STORE_load_locations", host, NULL); |
8b417f2c PH |
1359 | |
1360 | /* setting the flags to check against the complete crl chain */ | |
1361 | ||
1362 | X509_STORE_set_flags(cvstore, | |
1363 | X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL); | |
059ec3d9 | 1364 | } |
059ec3d9 PH |
1365 | } |
1366 | ||
1367 | #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ | |
1368 | ||
1369 | /* If verification is optional, don't fail if no certificate */ | |
1370 | ||
7be682ca | 1371 | SSL_CTX_set_verify(sctx, |
059ec3d9 | 1372 | SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT), |
983207c1 | 1373 | cert_vfy_cb); |
059ec3d9 PH |
1374 | } |
1375 | ||
1376 | return OK; | |
1377 | } | |
1378 | ||
1379 | ||
1380 | ||
1381 | /************************************************* | |
1382 | * Start a TLS session in a server * | |
1383 | *************************************************/ | |
1384 | ||
1385 | /* This is called when Exim is running as a server, after having received | |
1386 | the STARTTLS command. It must respond to that command, and then negotiate | |
1387 | a TLS session. | |
1388 | ||
1389 | Arguments: | |
1390 | require_ciphers allowed ciphers | |
1391 | ||
1392 | Returns: OK on success | |
1393 | DEFER for errors before the start of the negotiation | |
1394 | FAIL for errors during the negotation; the server can't | |
1395 | continue running. | |
1396 | */ | |
1397 | ||
1398 | int | |
17c76198 | 1399 | tls_server_start(const uschar *require_ciphers) |
059ec3d9 PH |
1400 | { |
1401 | int rc; | |
1402 | uschar *expciphers; | |
7be682ca | 1403 | tls_ext_ctx_cb *cbinfo; |
817d9f57 | 1404 | static uschar cipherbuf[256]; |
059ec3d9 PH |
1405 | |
1406 | /* Check for previous activation */ | |
1407 | ||
817d9f57 | 1408 | if (tls_in.active >= 0) |
059ec3d9 | 1409 | { |
5ca6d115 | 1410 | tls_error(US"STARTTLS received after TLS started", NULL, US""); |
059ec3d9 PH |
1411 | smtp_printf("554 Already in TLS\r\n"); |
1412 | return FAIL; | |
1413 | } | |
1414 | ||
1415 | /* Initialize the SSL library. If it fails, it will already have logged | |
1416 | the error. */ | |
1417 | ||
817d9f57 | 1418 | rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey, |
f2de3a33 | 1419 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1420 | tls_ocsp_file, |
1421 | #endif | |
817d9f57 | 1422 | NULL, &server_static_cbinfo); |
059ec3d9 | 1423 | if (rc != OK) return rc; |
817d9f57 | 1424 | cbinfo = server_static_cbinfo; |
059ec3d9 PH |
1425 | |
1426 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers)) | |
1427 | return FAIL; | |
1428 | ||
1429 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
17c76198 PP |
1430 | were historically separated by underscores. So that I can use either form in my |
1431 | tests, and also for general convenience, we turn underscores into hyphens here. | |
1432 | */ | |
059ec3d9 PH |
1433 | |
1434 | if (expciphers != NULL) | |
1435 | { | |
1436 | uschar *s = expciphers; | |
1437 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1438 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1439 | if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) |
7199e1ee | 1440 | return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL); |
7be682ca | 1441 | cbinfo->server_cipher_list = expciphers; |
059ec3d9 PH |
1442 | } |
1443 | ||
1444 | /* If this is a host for which certificate verification is mandatory or | |
1445 | optional, set up appropriately. */ | |
1446 | ||
817d9f57 | 1447 | tls_in.certificate_verified = FALSE; |
53a7196b JH |
1448 | #ifdef EXPERIMENTAL_DANE |
1449 | tls_in.dane_verified = FALSE; | |
1450 | #endif | |
a2ff477a | 1451 | server_verify_callback_called = FALSE; |
059ec3d9 PH |
1452 | |
1453 | if (verify_check_host(&tls_verify_hosts) == OK) | |
1454 | { | |
983207c1 JH |
1455 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
1456 | FALSE, verify_callback_server); | |
059ec3d9 | 1457 | if (rc != OK) return rc; |
a2ff477a | 1458 | server_verify_optional = FALSE; |
059ec3d9 PH |
1459 | } |
1460 | else if (verify_check_host(&tls_try_verify_hosts) == OK) | |
1461 | { | |
983207c1 JH |
1462 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
1463 | TRUE, verify_callback_server); | |
059ec3d9 | 1464 | if (rc != OK) return rc; |
a2ff477a | 1465 | server_verify_optional = TRUE; |
059ec3d9 PH |
1466 | } |
1467 | ||
1468 | /* Prepare for new connection */ | |
1469 | ||
817d9f57 | 1470 | if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL); |
da3ad30d PP |
1471 | |
1472 | /* Warning: we used to SSL_clear(ssl) here, it was removed. | |
1473 | * | |
1474 | * With the SSL_clear(), we get strange interoperability bugs with | |
1475 | * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in | |
1476 | * OpenSSL itself, as a clear should not lead to inability to follow protocols. | |
1477 | * | |
1478 | * The SSL_clear() call is to let an existing SSL* be reused, typically after | |
1479 | * session shutdown. In this case, we have a brand new object and there's no | |
1480 | * obvious reason to immediately clear it. I'm guessing that this was | |
1481 | * originally added because of incomplete initialisation which the clear fixed, | |
1482 | * in some historic release. | |
1483 | */ | |
059ec3d9 PH |
1484 | |
1485 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
1486 | on connection, where outputting anything now upsets the clients and tends to | |
1487 | make them disconnect. We need to have an explicit fflush() here, to force out | |
1488 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
1489 | mode, the fflush() happens when smtp_getc() is called. */ | |
1490 | ||
817d9f57 JH |
1491 | SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1492 | if (!tls_in.on_connect) | |
059ec3d9 PH |
1493 | { |
1494 | smtp_printf("220 TLS go ahead\r\n"); | |
1495 | fflush(smtp_out); | |
1496 | } | |
1497 | ||
1498 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
1499 | that the OpenSSL library doesn't. */ | |
1500 | ||
817d9f57 JH |
1501 | SSL_set_wfd(server_ssl, fileno(smtp_out)); |
1502 | SSL_set_rfd(server_ssl, fileno(smtp_in)); | |
1503 | SSL_set_accept_state(server_ssl); | |
059ec3d9 PH |
1504 | |
1505 | DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); | |
1506 | ||
1507 | sigalrm_seen = FALSE; | |
1508 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 | 1509 | rc = SSL_accept(server_ssl); |
059ec3d9 PH |
1510 | alarm(0); |
1511 | ||
1512 | if (rc <= 0) | |
1513 | { | |
7199e1ee | 1514 | tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL); |
77bb000f PP |
1515 | if (ERR_get_error() == 0) |
1516 | log_write(0, LOG_MAIN, | |
a053d125 | 1517 | "TLS client disconnected cleanly (rejected our certificate?)"); |
059ec3d9 PH |
1518 | return FAIL; |
1519 | } | |
1520 | ||
1521 | DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); | |
1522 | ||
1523 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
1524 | and initialize things. */ | |
1525 | ||
817d9f57 JH |
1526 | construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits); |
1527 | tls_in.cipher = cipherbuf; | |
059ec3d9 PH |
1528 | |
1529 | DEBUG(D_tls) | |
1530 | { | |
1531 | uschar buf[2048]; | |
817d9f57 | 1532 | if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL) |
059ec3d9 PH |
1533 | debug_printf("Shared ciphers: %s\n", buf); |
1534 | } | |
1535 | ||
9d1c15ef JH |
1536 | /* Record the certificate we presented */ |
1537 | { | |
1538 | X509 * crt = SSL_get_certificate(server_ssl); | |
1539 | tls_in.ourcert = crt ? X509_dup(crt) : NULL; | |
1540 | } | |
059ec3d9 | 1541 | |
817d9f57 JH |
1542 | /* Only used by the server-side tls (tls_in), including tls_getc. |
1543 | Client-side (tls_out) reads (seem to?) go via | |
1544 | smtp_read_response()/ip_recv(). | |
1545 | Hence no need to duplicate for _in and _out. | |
1546 | */ | |
059ec3d9 PH |
1547 | ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
1548 | ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; | |
1549 | ssl_xfer_eof = ssl_xfer_error = 0; | |
1550 | ||
1551 | receive_getc = tls_getc; | |
1552 | receive_ungetc = tls_ungetc; | |
1553 | receive_feof = tls_feof; | |
1554 | receive_ferror = tls_ferror; | |
58eb016e | 1555 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 1556 | |
817d9f57 | 1557 | tls_in.active = fileno(smtp_out); |
059ec3d9 PH |
1558 | return OK; |
1559 | } | |
1560 | ||
1561 | ||
1562 | ||
1563 | ||
043b1248 JH |
1564 | static int |
1565 | tls_client_basic_ctx_init(SSL_CTX * ctx, | |
1566 | host_item * host, smtp_transport_options_block * ob | |
1567 | #ifdef EXPERIMENTAL_CERTNAMES | |
1568 | , tls_ext_ctx_cb * cbinfo | |
1569 | #endif | |
1570 | ) | |
1571 | { | |
1572 | int rc; | |
1573 | /* stick to the old behaviour for compatibility if tls_verify_certificates is | |
1574 | set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only | |
1575 | the specified host patterns if one of them is defined */ | |
1576 | ||
1577 | if ((!ob->tls_verify_hosts && !ob->tls_try_verify_hosts) || | |
1578 | (verify_check_host(&ob->tls_verify_hosts) == OK)) | |
1579 | { | |
1580 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
1581 | ob->tls_crl, host, FALSE, verify_callback_client)) != OK) | |
1582 | return rc; | |
1583 | client_verify_optional = FALSE; | |
1584 | ||
1585 | #ifdef EXPERIMENTAL_CERTNAMES | |
1586 | if (ob->tls_verify_cert_hostnames) | |
1587 | { | |
1588 | if (!expand_check(ob->tls_verify_cert_hostnames, | |
1589 | US"tls_verify_cert_hostnames", | |
1590 | &cbinfo->verify_cert_hostnames)) | |
1591 | return FAIL; | |
1592 | if (cbinfo->verify_cert_hostnames) | |
1593 | DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", | |
1594 | cbinfo->verify_cert_hostnames); | |
1595 | } | |
1596 | #endif | |
1597 | } | |
1598 | else if (verify_check_host(&ob->tls_try_verify_hosts) == OK) | |
1599 | { | |
1600 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
1601 | ob->tls_crl, host, TRUE, verify_callback_client)) != OK) | |
1602 | return rc; | |
1603 | client_verify_optional = TRUE; | |
1604 | } | |
1605 | ||
1606 | return OK; | |
1607 | } | |
059ec3d9 PH |
1608 | |
1609 | /************************************************* | |
1610 | * Start a TLS session in a client * | |
1611 | *************************************************/ | |
1612 | ||
1613 | /* Called from the smtp transport after STARTTLS has been accepted. | |
1614 | ||
1615 | Argument: | |
1616 | fd the fd of the connection | |
1617 | host connected host (for messages) | |
83da1223 | 1618 | addr the first address |
65867078 | 1619 | ob smtp transport options |
059ec3d9 PH |
1620 | |
1621 | Returns: OK on success | |
1622 | FAIL otherwise - note that tls_error() will not give DEFER | |
1623 | because this is not a server | |
1624 | */ | |
1625 | ||
1626 | int | |
f5d78688 | 1627 | tls_client_start(int fd, host_item *host, address_item *addr, |
65867078 | 1628 | void *v_ob) |
059ec3d9 | 1629 | { |
65867078 | 1630 | smtp_transport_options_block * ob = v_ob; |
059ec3d9 | 1631 | static uschar txt[256]; |
868f5672 JH |
1632 | uschar * expciphers; |
1633 | X509 * server_cert; | |
059ec3d9 | 1634 | int rc; |
817d9f57 | 1635 | static uschar cipherbuf[256]; |
043b1248 JH |
1636 | |
1637 | #ifndef DISABLE_OCSP | |
043b1248 | 1638 | BOOL request_ocsp = FALSE; |
6634ac8d | 1639 | BOOL require_ocsp = FALSE; |
043b1248 JH |
1640 | #endif |
1641 | #ifdef EXPERIMENTAL_DANE | |
868f5672 JH |
1642 | dns_answer tlsa_dnsa; |
1643 | BOOL dane = FALSE; | |
1644 | BOOL dane_required; | |
043b1248 JH |
1645 | #endif |
1646 | ||
1647 | #ifdef EXPERIMENTAL_DANE | |
868f5672 JH |
1648 | dane_required = verify_check_this_host(&ob->hosts_require_dane, NULL, |
1649 | host->name, host->address, NULL) == OK; | |
868f5672 JH |
1650 | |
1651 | if (host->dnssec == DS_YES) | |
1652 | { | |
1653 | if( dane_required | |
1654 | || verify_check_this_host(&ob->hosts_try_dane, NULL, | |
1655 | host->name, host->address, NULL) == OK | |
1656 | ) | |
1657 | { | |
1658 | /* move this out to host.c given the similarity to dns_lookup() ? */ | |
1659 | uschar buffer[300]; | |
868f5672 JH |
1660 | uschar * fullname = buffer; |
1661 | ||
1662 | /* TLSA lookup string */ | |
7a31d643 | 1663 | (void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port, |
868f5672 JH |
1664 | host->name); |
1665 | ||
1666 | switch (rc = dns_lookup(&tlsa_dnsa, buffer, T_TLSA, &fullname)) | |
1667 | { | |
1668 | case DNS_AGAIN: | |
1669 | return DEFER; /* just defer this TLS'd conn */ | |
1670 | ||
1671 | default: | |
1672 | case DNS_FAIL: | |
1673 | if (dane_required) | |
1674 | { | |
7a31d643 | 1675 | log_write(0, LOG_MAIN, "DANE error: TLSA lookup failed"); |
868f5672 JH |
1676 | return FAIL; |
1677 | } | |
1678 | break; | |
1679 | ||
1680 | case DNS_SUCCEED: | |
1681 | if (!dns_is_secure(&tlsa_dnsa)) | |
1682 | { | |
7a31d643 | 1683 | log_write(0, LOG_MAIN, "DANE error: TLSA lookup not DNSSEC"); |
868f5672 JH |
1684 | return DEFER; |
1685 | } | |
1686 | dane = TRUE; | |
1687 | break; | |
1688 | } | |
1689 | } | |
1690 | } | |
7a31d643 | 1691 | else if (dane_required) |
868f5672 | 1692 | { |
cf2b569e | 1693 | /*XXX a shame we only find this after making tcp & smtp connection */ |
b4161d10 | 1694 | /* move the test earlier? */ |
7a31d643 | 1695 | log_write(0, LOG_MAIN, "DANE error: previous lookup not DNSSEC"); |
868f5672 JH |
1696 | return FAIL; |
1697 | } | |
043b1248 | 1698 | |
043b1248 JH |
1699 | #endif |
1700 | ||
f2de3a33 | 1701 | #ifndef DISABLE_OCSP |
043b1248 JH |
1702 | { |
1703 | require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp, | |
1704 | NULL, host->name, host->address, NULL) == OK; | |
1705 | request_ocsp = require_ocsp ? TRUE | |
1706 | : verify_check_this_host(&ob->hosts_request_ocsp, | |
1707 | NULL, host->name, host->address, NULL) == OK; | |
1708 | } | |
f5d78688 | 1709 | #endif |
059ec3d9 | 1710 | |
65867078 JH |
1711 | rc = tls_init(&client_ctx, host, NULL, |
1712 | ob->tls_certificate, ob->tls_privatekey, | |
f2de3a33 | 1713 | #ifndef DISABLE_OCSP |
44662487 | 1714 | (void *)(long)request_ocsp, |
3f7eeb86 | 1715 | #endif |
817d9f57 | 1716 | addr, &client_static_cbinfo); |
059ec3d9 PH |
1717 | if (rc != OK) return rc; |
1718 | ||
817d9f57 | 1719 | tls_out.certificate_verified = FALSE; |
53a7196b JH |
1720 | #ifdef EXPERIMENTAL_DANE |
1721 | tls_out.dane_verified = FALSE; | |
1722 | #endif | |
a2ff477a | 1723 | client_verify_callback_called = FALSE; |
059ec3d9 | 1724 | |
65867078 JH |
1725 | if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers", |
1726 | &expciphers)) | |
059ec3d9 PH |
1727 | return FAIL; |
1728 | ||
1729 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
1730 | are separated by underscores. So that I can use either form in my tests, and | |
1731 | also for general convenience, we turn underscores into hyphens here. */ | |
1732 | ||
1733 | if (expciphers != NULL) | |
1734 | { | |
1735 | uschar *s = expciphers; | |
1736 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1737 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1738 | if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers)) |
7199e1ee | 1739 | return tls_error(US"SSL_CTX_set_cipher_list", host, NULL); |
059ec3d9 PH |
1740 | } |
1741 | ||
043b1248 | 1742 | #ifdef EXPERIMENTAL_DANE |
868f5672 | 1743 | if (dane) |
a63be306 | 1744 | { |
e5cccda9 JH |
1745 | SSL_CTX_set_verify(client_ctx, SSL_VERIFY_PEER, verify_callback_client_dane); |
1746 | ||
043b1248 | 1747 | if (!DANESSL_library_init()) |
b4161d10 | 1748 | return tls_error(US"library init", host, NULL); |
043b1248 | 1749 | if (DANESSL_CTX_init(client_ctx) <= 0) |
b4161d10 | 1750 | return tls_error(US"context init", host, NULL); |
043b1248 JH |
1751 | } |
1752 | else | |
e51c7be2 | 1753 | |
043b1248 JH |
1754 | #endif |
1755 | ||
1756 | if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob | |
e51c7be2 | 1757 | #ifdef EXPERIMENTAL_CERTNAMES |
043b1248 | 1758 | , client_static_cbinfo |
e51c7be2 | 1759 | #endif |
043b1248 | 1760 | )) != OK) |
65867078 | 1761 | return rc; |
059ec3d9 | 1762 | |
65867078 JH |
1763 | if ((client_ssl = SSL_new(client_ctx)) == NULL) |
1764 | return tls_error(US"SSL_new", host, NULL); | |
817d9f57 JH |
1765 | SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1766 | SSL_set_fd(client_ssl, fd); | |
1767 | SSL_set_connect_state(client_ssl); | |
059ec3d9 | 1768 | |
65867078 | 1769 | if (ob->tls_sni) |
3f0945ff | 1770 | { |
65867078 | 1771 | if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni)) |
3f0945ff | 1772 | return FAIL; |
ec4b68e5 | 1773 | if (tls_out.sni == NULL) |
2c9a0e86 PP |
1774 | { |
1775 | DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n"); | |
1776 | } | |
ec4b68e5 | 1777 | else if (!Ustrlen(tls_out.sni)) |
817d9f57 | 1778 | tls_out.sni = NULL; |
3f0945ff PP |
1779 | else |
1780 | { | |
35731706 | 1781 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 JH |
1782 | DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni); |
1783 | SSL_set_tlsext_host_name(client_ssl, tls_out.sni); | |
35731706 PP |
1784 | #else |
1785 | DEBUG(D_tls) | |
1786 | debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n", | |
02d9264f | 1787 | tls_out.sni); |
35731706 | 1788 | #endif |
3f0945ff PP |
1789 | } |
1790 | } | |
1791 | ||
f2de3a33 | 1792 | #ifndef DISABLE_OCSP |
f5d78688 JH |
1793 | /* Request certificate status at connection-time. If the server |
1794 | does OCSP stapling we will get the callback (set in tls_init()) */ | |
44662487 JH |
1795 | if (request_ocsp) |
1796 | { | |
f5d78688 | 1797 | SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp); |
44662487 JH |
1798 | client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp; |
1799 | tls_out.ocsp = OCSP_NOT_RESP; | |
1800 | } | |
f5d78688 JH |
1801 | #endif |
1802 | ||
043b1248 | 1803 | #ifdef EXPERIMENTAL_DANE |
868f5672 | 1804 | if (dane) |
043b1248 | 1805 | { |
868f5672 JH |
1806 | dns_record * rr; |
1807 | dns_scan dnss; | |
1808 | uschar * hostnames[2] = { host->name, NULL }; | |
1809 | ||
1810 | if (DANESSL_init(client_ssl, NULL, hostnames) != 1) | |
b4161d10 | 1811 | return tls_error(US"hostnames load", host, NULL); |
043b1248 | 1812 | |
868f5672 JH |
1813 | for (rr = dns_next_rr(&tlsa_dnsa, &dnss, RESET_ANSWERS); |
1814 | rr; | |
1815 | rr = dns_next_rr(&tlsa_dnsa, &dnss, RESET_NEXT) | |
1816 | ) if (rr->type == T_TLSA) | |
1817 | { | |
1818 | uschar * p = rr->data; | |
1819 | int usage, selector, mtype; | |
1820 | const char * mdname; | |
1821 | ||
1822 | GETSHORT(usage, p); | |
1823 | GETSHORT(selector, p); | |
1824 | GETSHORT(mtype, p); | |
1825 | ||
1826 | switch (mtype) | |
1827 | { | |
1828 | default: /* log bad */ return FAIL; | |
1829 | case 0: mdname = NULL; break; | |
401a8935 JH |
1830 | case 1: mdname = "sha256"; break; |
1831 | case 2: mdname = "sha512"; break; | |
868f5672 JH |
1832 | } |
1833 | ||
1834 | switch (DANESSL_add_tlsa(client_ssl, | |
1835 | (uint8_t) usage, (uint8_t) selector, | |
1836 | mdname, p, rr->size - (p - rr->data))) | |
1837 | { | |
1838 | default: | |
b4161d10 JH |
1839 | case 0: /* action not taken */ |
1840 | return tls_error(US"tlsa load", host, NULL); | |
868f5672 JH |
1841 | case 1: break; |
1842 | } | |
1843 | } | |
043b1248 JH |
1844 | } |
1845 | #endif | |
1846 | ||
1847 | ||
059ec3d9 PH |
1848 | /* There doesn't seem to be a built-in timeout on connection. */ |
1849 | ||
1850 | DEBUG(D_tls) debug_printf("Calling SSL_connect\n"); | |
1851 | sigalrm_seen = FALSE; | |
65867078 | 1852 | alarm(ob->command_timeout); |
817d9f57 | 1853 | rc = SSL_connect(client_ssl); |
059ec3d9 PH |
1854 | alarm(0); |
1855 | ||
043b1248 | 1856 | #ifdef EXPERIMENTAL_DANE |
12ee8cf9 JH |
1857 | if (dane) |
1858 | DANESSL_cleanup(client_ssl); /*XXX earliest possible callpoint. Too early? */ | |
043b1248 JH |
1859 | #endif |
1860 | ||
059ec3d9 | 1861 | if (rc <= 0) |
7199e1ee | 1862 | return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL); |
059ec3d9 PH |
1863 | |
1864 | DEBUG(D_tls) debug_printf("SSL_connect succeeded\n"); | |
1865 | ||
453a6645 | 1866 | /* Beware anonymous ciphers which lead to server_cert being NULL */ |
9d1c15ef | 1867 | /*XXX server_cert is never freed... use X509_free() */ |
817d9f57 | 1868 | server_cert = SSL_get_peer_certificate (client_ssl); |
453a6645 PP |
1869 | if (server_cert) |
1870 | { | |
817d9f57 | 1871 | tls_out.peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert), |
453a6645 | 1872 | CS txt, sizeof(txt)); |
9d1c15ef | 1873 | tls_out.peerdn = txt; /*XXX a static buffer... */ |
453a6645 PP |
1874 | } |
1875 | else | |
817d9f57 | 1876 | tls_out.peerdn = NULL; |
059ec3d9 | 1877 | |
817d9f57 JH |
1878 | construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits); |
1879 | tls_out.cipher = cipherbuf; | |
059ec3d9 | 1880 | |
9d1c15ef JH |
1881 | /* Record the certificate we presented */ |
1882 | { | |
1883 | X509 * crt = SSL_get_certificate(client_ssl); | |
1884 | tls_out.ourcert = crt ? X509_dup(crt) : NULL; | |
1885 | } | |
1886 | ||
817d9f57 | 1887 | tls_out.active = fd; |
059ec3d9 PH |
1888 | return OK; |
1889 | } | |
1890 | ||
1891 | ||
1892 | ||
1893 | ||
1894 | ||
1895 | /************************************************* | |
1896 | * TLS version of getc * | |
1897 | *************************************************/ | |
1898 | ||
1899 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
1900 | it refills the buffer via the SSL reading function. | |
1901 | ||
1902 | Arguments: none | |
1903 | Returns: the next character or EOF | |
817d9f57 JH |
1904 | |
1905 | Only used by the server-side TLS. | |
059ec3d9 PH |
1906 | */ |
1907 | ||
1908 | int | |
1909 | tls_getc(void) | |
1910 | { | |
1911 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) | |
1912 | { | |
1913 | int error; | |
1914 | int inbytes; | |
1915 | ||
817d9f57 | 1916 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl, |
c80c5570 | 1917 | ssl_xfer_buffer, ssl_xfer_buffer_size); |
059ec3d9 PH |
1918 | |
1919 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 JH |
1920 | inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size); |
1921 | error = SSL_get_error(server_ssl, inbytes); | |
059ec3d9 PH |
1922 | alarm(0); |
1923 | ||
1924 | /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been | |
1925 | closed down, not that the socket itself has been closed down. Revert to | |
1926 | non-SSL handling. */ | |
1927 | ||
1928 | if (error == SSL_ERROR_ZERO_RETURN) | |
1929 | { | |
1930 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
1931 | ||
1932 | receive_getc = smtp_getc; | |
1933 | receive_ungetc = smtp_ungetc; | |
1934 | receive_feof = smtp_feof; | |
1935 | receive_ferror = smtp_ferror; | |
58eb016e | 1936 | receive_smtp_buffered = smtp_buffered; |
059ec3d9 | 1937 | |
817d9f57 JH |
1938 | SSL_free(server_ssl); |
1939 | server_ssl = NULL; | |
1940 | tls_in.active = -1; | |
1941 | tls_in.bits = 0; | |
1942 | tls_in.cipher = NULL; | |
1943 | tls_in.peerdn = NULL; | |
1944 | tls_in.sni = NULL; | |
059ec3d9 PH |
1945 | |
1946 | return smtp_getc(); | |
1947 | } | |
1948 | ||
1949 | /* Handle genuine errors */ | |
1950 | ||
ba084640 PP |
1951 | else if (error == SSL_ERROR_SSL) |
1952 | { | |
1953 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
89dd51cd | 1954 | log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); |
ba084640 PP |
1955 | ssl_xfer_error = 1; |
1956 | return EOF; | |
1957 | } | |
1958 | ||
059ec3d9 PH |
1959 | else if (error != SSL_ERROR_NONE) |
1960 | { | |
1961 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
1962 | ssl_xfer_error = 1; | |
1963 | return EOF; | |
1964 | } | |
c80c5570 | 1965 | |
80a47a2c TK |
1966 | #ifndef DISABLE_DKIM |
1967 | dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); | |
1968 | #endif | |
059ec3d9 PH |
1969 | ssl_xfer_buffer_hwm = inbytes; |
1970 | ssl_xfer_buffer_lwm = 0; | |
1971 | } | |
1972 | ||
1973 | /* Something in the buffer; return next uschar */ | |
1974 | ||
1975 | return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; | |
1976 | } | |
1977 | ||
1978 | ||
1979 | ||
1980 | /************************************************* | |
1981 | * Read bytes from TLS channel * | |
1982 | *************************************************/ | |
1983 | ||
1984 | /* | |
1985 | Arguments: | |
1986 | buff buffer of data | |
1987 | len size of buffer | |
1988 | ||
1989 | Returns: the number of bytes read | |
1990 | -1 after a failed read | |
817d9f57 JH |
1991 | |
1992 | Only used by the client-side TLS. | |
059ec3d9 PH |
1993 | */ |
1994 | ||
1995 | int | |
389ca47a | 1996 | tls_read(BOOL is_server, uschar *buff, size_t len) |
059ec3d9 | 1997 | { |
389ca47a | 1998 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 PH |
1999 | int inbytes; |
2000 | int error; | |
2001 | ||
389ca47a | 2002 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl, |
c80c5570 | 2003 | buff, (unsigned int)len); |
059ec3d9 | 2004 | |
389ca47a JH |
2005 | inbytes = SSL_read(ssl, CS buff, len); |
2006 | error = SSL_get_error(ssl, inbytes); | |
059ec3d9 PH |
2007 | |
2008 | if (error == SSL_ERROR_ZERO_RETURN) | |
2009 | { | |
2010 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2011 | return -1; | |
2012 | } | |
2013 | else if (error != SSL_ERROR_NONE) | |
2014 | { | |
2015 | return -1; | |
2016 | } | |
2017 | ||
2018 | return inbytes; | |
2019 | } | |
2020 | ||
2021 | ||
2022 | ||
2023 | ||
2024 | ||
2025 | /************************************************* | |
2026 | * Write bytes down TLS channel * | |
2027 | *************************************************/ | |
2028 | ||
2029 | /* | |
2030 | Arguments: | |
817d9f57 | 2031 | is_server channel specifier |
059ec3d9 PH |
2032 | buff buffer of data |
2033 | len number of bytes | |
2034 | ||
2035 | Returns: the number of bytes after a successful write, | |
2036 | -1 after a failed write | |
817d9f57 JH |
2037 | |
2038 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2039 | */ |
2040 | ||
2041 | int | |
817d9f57 | 2042 | tls_write(BOOL is_server, const uschar *buff, size_t len) |
059ec3d9 PH |
2043 | { |
2044 | int outbytes; | |
2045 | int error; | |
2046 | int left = len; | |
817d9f57 | 2047 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 | 2048 | |
c80c5570 | 2049 | DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left); |
059ec3d9 PH |
2050 | while (left > 0) |
2051 | { | |
c80c5570 | 2052 | DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left); |
059ec3d9 PH |
2053 | outbytes = SSL_write(ssl, CS buff, left); |
2054 | error = SSL_get_error(ssl, outbytes); | |
2055 | DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error); | |
2056 | switch (error) | |
2057 | { | |
2058 | case SSL_ERROR_SSL: | |
2059 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2060 | log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); | |
2061 | return -1; | |
2062 | ||
2063 | case SSL_ERROR_NONE: | |
2064 | left -= outbytes; | |
2065 | buff += outbytes; | |
2066 | break; | |
2067 | ||
2068 | case SSL_ERROR_ZERO_RETURN: | |
2069 | log_write(0, LOG_MAIN, "SSL channel closed on write"); | |
2070 | return -1; | |
2071 | ||
817d9f57 JH |
2072 | case SSL_ERROR_SYSCALL: |
2073 | log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", | |
2074 | sender_fullhost ? sender_fullhost : US"<unknown>", | |
2075 | strerror(errno)); | |
2076 | ||
059ec3d9 PH |
2077 | default: |
2078 | log_write(0, LOG_MAIN, "SSL_write error %d", error); | |
2079 | return -1; | |
2080 | } | |
2081 | } | |
2082 | return len; | |
2083 | } | |
2084 | ||
2085 | ||
2086 | ||
2087 | /************************************************* | |
2088 | * Close down a TLS session * | |
2089 | *************************************************/ | |
2090 | ||
2091 | /* This is also called from within a delivery subprocess forked from the | |
2092 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
2093 | would tamper with the SSL session in the parent process). | |
2094 | ||
2095 | Arguments: TRUE if SSL_shutdown is to be called | |
2096 | Returns: nothing | |
817d9f57 JH |
2097 | |
2098 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
2099 | */ |
2100 | ||
2101 | void | |
817d9f57 | 2102 | tls_close(BOOL is_server, BOOL shutdown) |
059ec3d9 | 2103 | { |
817d9f57 | 2104 | SSL **sslp = is_server ? &server_ssl : &client_ssl; |
389ca47a | 2105 | int *fdp = is_server ? &tls_in.active : &tls_out.active; |
817d9f57 JH |
2106 | |
2107 | if (*fdp < 0) return; /* TLS was not active */ | |
059ec3d9 PH |
2108 | |
2109 | if (shutdown) | |
2110 | { | |
2111 | DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n"); | |
817d9f57 | 2112 | SSL_shutdown(*sslp); |
059ec3d9 PH |
2113 | } |
2114 | ||
817d9f57 JH |
2115 | SSL_free(*sslp); |
2116 | *sslp = NULL; | |
059ec3d9 | 2117 | |
817d9f57 | 2118 | *fdp = -1; |
059ec3d9 PH |
2119 | } |
2120 | ||
36f12725 NM |
2121 | |
2122 | ||
2123 | ||
3375e053 PP |
2124 | /************************************************* |
2125 | * Let tls_require_ciphers be checked at startup * | |
2126 | *************************************************/ | |
2127 | ||
2128 | /* The tls_require_ciphers option, if set, must be something which the | |
2129 | library can parse. | |
2130 | ||
2131 | Returns: NULL on success, or error message | |
2132 | */ | |
2133 | ||
2134 | uschar * | |
2135 | tls_validate_require_cipher(void) | |
2136 | { | |
2137 | SSL_CTX *ctx; | |
2138 | uschar *s, *expciphers, *err; | |
2139 | ||
2140 | /* this duplicates from tls_init(), we need a better "init just global | |
2141 | state, for no specific purpose" singleton function of our own */ | |
2142 | ||
2143 | SSL_load_error_strings(); | |
2144 | OpenSSL_add_ssl_algorithms(); | |
2145 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
2146 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the | |
2147 | list of available digests. */ | |
2148 | EVP_add_digest(EVP_sha256()); | |
2149 | #endif | |
2150 | ||
2151 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
2152 | return NULL; | |
2153 | ||
2154 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers)) | |
2155 | return US"failed to expand tls_require_ciphers"; | |
2156 | ||
2157 | if (!(expciphers && *expciphers)) | |
2158 | return NULL; | |
2159 | ||
2160 | /* normalisation ripped from above */ | |
2161 | s = expciphers; | |
2162 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
2163 | ||
2164 | err = NULL; | |
2165 | ||
2166 | ctx = SSL_CTX_new(SSLv23_server_method()); | |
2167 | if (!ctx) | |
2168 | { | |
2169 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2170 | return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring); | |
2171 | } | |
2172 | ||
2173 | DEBUG(D_tls) | |
2174 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
2175 | ||
2176 | if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) | |
2177 | { | |
2178 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
2179 | err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers); | |
2180 | } | |
2181 | ||
2182 | SSL_CTX_free(ctx); | |
2183 | ||
2184 | return err; | |
2185 | } | |
2186 | ||
2187 | ||
2188 | ||
2189 | ||
36f12725 NM |
2190 | /************************************************* |
2191 | * Report the library versions. * | |
2192 | *************************************************/ | |
2193 | ||
2194 | /* There have historically been some issues with binary compatibility in | |
2195 | OpenSSL libraries; if Exim (like many other applications) is built against | |
2196 | one version of OpenSSL but the run-time linker picks up another version, | |
2197 | it can result in serious failures, including crashing with a SIGSEGV. So | |
2198 | report the version found by the compiler and the run-time version. | |
2199 | ||
f64a1e23 PP |
2200 | Note: some OS vendors backport security fixes without changing the version |
2201 | number/string, and the version date remains unchanged. The _build_ date | |
2202 | will change, so we can more usefully assist with version diagnosis by also | |
2203 | reporting the build date. | |
2204 | ||
36f12725 NM |
2205 | Arguments: a FILE* to print the results to |
2206 | Returns: nothing | |
2207 | */ | |
2208 | ||
2209 | void | |
2210 | tls_version_report(FILE *f) | |
2211 | { | |
754a0503 | 2212 | fprintf(f, "Library version: OpenSSL: Compile: %s\n" |
f64a1e23 PP |
2213 | " Runtime: %s\n" |
2214 | " : %s\n", | |
754a0503 | 2215 | OPENSSL_VERSION_TEXT, |
f64a1e23 PP |
2216 | SSLeay_version(SSLEAY_VERSION), |
2217 | SSLeay_version(SSLEAY_BUILT_ON)); | |
2218 | /* third line is 38 characters for the %s and the line is 73 chars long; | |
2219 | the OpenSSL output includes a "built on: " prefix already. */ | |
36f12725 NM |
2220 | } |
2221 | ||
9e3331ea TK |
2222 | |
2223 | ||
2224 | ||
2225 | /************************************************* | |
17c76198 | 2226 | * Random number generation * |
9e3331ea TK |
2227 | *************************************************/ |
2228 | ||
2229 | /* Pseudo-random number generation. The result is not expected to be | |
2230 | cryptographically strong but not so weak that someone will shoot themselves | |
2231 | in the foot using it as a nonce in input in some email header scheme or | |
2232 | whatever weirdness they'll twist this into. The result should handle fork() | |
2233 | and avoid repeating sequences. OpenSSL handles that for us. | |
2234 | ||
2235 | Arguments: | |
2236 | max range maximum | |
2237 | Returns a random number in range [0, max-1] | |
2238 | */ | |
2239 | ||
2240 | int | |
17c76198 | 2241 | vaguely_random_number(int max) |
9e3331ea TK |
2242 | { |
2243 | unsigned int r; | |
2244 | int i, needed_len; | |
de6135a0 PP |
2245 | static pid_t pidlast = 0; |
2246 | pid_t pidnow; | |
9e3331ea TK |
2247 | uschar *p; |
2248 | uschar smallbuf[sizeof(r)]; | |
2249 | ||
2250 | if (max <= 1) | |
2251 | return 0; | |
2252 | ||
de6135a0 PP |
2253 | pidnow = getpid(); |
2254 | if (pidnow != pidlast) | |
2255 | { | |
2256 | /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state | |
2257 | is unique for each thread", this doesn't apparently apply across processes, | |
2258 | so our own warning from vaguely_random_number_fallback() applies here too. | |
2259 | Fix per PostgreSQL. */ | |
2260 | if (pidlast != 0) | |
2261 | RAND_cleanup(); | |
2262 | pidlast = pidnow; | |
2263 | } | |
2264 | ||
9e3331ea TK |
2265 | /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ |
2266 | if (!RAND_status()) | |
2267 | { | |
2268 | randstuff r; | |
2269 | gettimeofday(&r.tv, NULL); | |
2270 | r.p = getpid(); | |
2271 | ||
2272 | RAND_seed((uschar *)(&r), sizeof(r)); | |
2273 | } | |
2274 | /* We're after pseudo-random, not random; if we still don't have enough data | |
2275 | in the internal PRNG then our options are limited. We could sleep and hope | |
2276 | for entropy to come along (prayer technique) but if the system is so depleted | |
2277 | in the first place then something is likely to just keep taking it. Instead, | |
2278 | we'll just take whatever little bit of pseudo-random we can still manage to | |
2279 | get. */ | |
2280 | ||
2281 | needed_len = sizeof(r); | |
2282 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
2283 | asked for a number less than 10. */ | |
2284 | for (r = max, i = 0; r; ++i) | |
2285 | r >>= 1; | |
2286 | i = (i + 7) / 8; | |
2287 | if (i < needed_len) | |
2288 | needed_len = i; | |
2289 | ||
2290 | /* We do not care if crypto-strong */ | |
17c76198 PP |
2291 | i = RAND_pseudo_bytes(smallbuf, needed_len); |
2292 | if (i < 0) | |
2293 | { | |
2294 | DEBUG(D_all) | |
2295 | debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n"); | |
2296 | return vaguely_random_number_fallback(max); | |
2297 | } | |
2298 | ||
9e3331ea TK |
2299 | r = 0; |
2300 | for (p = smallbuf; needed_len; --needed_len, ++p) | |
2301 | { | |
2302 | r *= 256; | |
2303 | r += *p; | |
2304 | } | |
2305 | ||
2306 | /* We don't particularly care about weighted results; if someone wants | |
2307 | smooth distribution and cares enough then they should submit a patch then. */ | |
2308 | return r % max; | |
2309 | } | |
2310 | ||
77bb000f PP |
2311 | |
2312 | ||
2313 | ||
2314 | /************************************************* | |
2315 | * OpenSSL option parse * | |
2316 | *************************************************/ | |
2317 | ||
2318 | /* Parse one option for tls_openssl_options_parse below | |
2319 | ||
2320 | Arguments: | |
2321 | name one option name | |
2322 | value place to store a value for it | |
2323 | Returns success or failure in parsing | |
2324 | */ | |
2325 | ||
2326 | struct exim_openssl_option { | |
2327 | uschar *name; | |
2328 | long value; | |
2329 | }; | |
2330 | /* We could use a macro to expand, but we need the ifdef and not all the | |
2331 | options document which version they were introduced in. Policylet: include | |
2332 | all options unless explicitly for DTLS, let the administrator choose which | |
2333 | to apply. | |
2334 | ||
2335 | This list is current as of: | |
e2fbf4a2 PP |
2336 | ==> 1.0.1b <== |
2337 | Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev | |
2338 | */ | |
77bb000f PP |
2339 | static struct exim_openssl_option exim_openssl_options[] = { |
2340 | /* KEEP SORTED ALPHABETICALLY! */ | |
2341 | #ifdef SSL_OP_ALL | |
73a46702 | 2342 | { US"all", SSL_OP_ALL }, |
77bb000f PP |
2343 | #endif |
2344 | #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION | |
73a46702 | 2345 | { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, |
77bb000f PP |
2346 | #endif |
2347 | #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE | |
73a46702 | 2348 | { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, |
77bb000f PP |
2349 | #endif |
2350 | #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS | |
73a46702 | 2351 | { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, |
77bb000f PP |
2352 | #endif |
2353 | #ifdef SSL_OP_EPHEMERAL_RSA | |
73a46702 | 2354 | { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, |
77bb000f PP |
2355 | #endif |
2356 | #ifdef SSL_OP_LEGACY_SERVER_CONNECT | |
73a46702 | 2357 | { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, |
77bb000f PP |
2358 | #endif |
2359 | #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER | |
73a46702 | 2360 | { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, |
77bb000f PP |
2361 | #endif |
2362 | #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG | |
73a46702 | 2363 | { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, |
77bb000f PP |
2364 | #endif |
2365 | #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING | |
73a46702 | 2366 | { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, |
77bb000f PP |
2367 | #endif |
2368 | #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG | |
73a46702 | 2369 | { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, |
77bb000f PP |
2370 | #endif |
2371 | #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG | |
73a46702 | 2372 | { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, |
77bb000f | 2373 | #endif |
c80c5570 PP |
2374 | #ifdef SSL_OP_NO_COMPRESSION |
2375 | { US"no_compression", SSL_OP_NO_COMPRESSION }, | |
2376 | #endif | |
77bb000f | 2377 | #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |
73a46702 | 2378 | { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, |
77bb000f | 2379 | #endif |
c0c7b2da PP |
2380 | #ifdef SSL_OP_NO_SSLv2 |
2381 | { US"no_sslv2", SSL_OP_NO_SSLv2 }, | |
2382 | #endif | |
2383 | #ifdef SSL_OP_NO_SSLv3 | |
2384 | { US"no_sslv3", SSL_OP_NO_SSLv3 }, | |
2385 | #endif | |
2386 | #ifdef SSL_OP_NO_TICKET | |
2387 | { US"no_ticket", SSL_OP_NO_TICKET }, | |
2388 | #endif | |
2389 | #ifdef SSL_OP_NO_TLSv1 | |
2390 | { US"no_tlsv1", SSL_OP_NO_TLSv1 }, | |
2391 | #endif | |
c80c5570 PP |
2392 | #ifdef SSL_OP_NO_TLSv1_1 |
2393 | #if SSL_OP_NO_TLSv1_1 == 0x00000400L | |
2394 | /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */ | |
2395 | #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring | |
2396 | #else | |
2397 | { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 }, | |
2398 | #endif | |
2399 | #endif | |
2400 | #ifdef SSL_OP_NO_TLSv1_2 | |
2401 | { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 }, | |
2402 | #endif | |
e2fbf4a2 PP |
2403 | #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG |
2404 | { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG }, | |
2405 | #endif | |
77bb000f | 2406 | #ifdef SSL_OP_SINGLE_DH_USE |
73a46702 | 2407 | { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, |
77bb000f PP |
2408 | #endif |
2409 | #ifdef SSL_OP_SINGLE_ECDH_USE | |
73a46702 | 2410 | { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, |
77bb000f PP |
2411 | #endif |
2412 | #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG | |
73a46702 | 2413 | { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, |
77bb000f PP |
2414 | #endif |
2415 | #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG | |
73a46702 | 2416 | { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, |
77bb000f PP |
2417 | #endif |
2418 | #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG | |
73a46702 | 2419 | { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, |
77bb000f PP |
2420 | #endif |
2421 | #ifdef SSL_OP_TLS_D5_BUG | |
73a46702 | 2422 | { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, |
77bb000f PP |
2423 | #endif |
2424 | #ifdef SSL_OP_TLS_ROLLBACK_BUG | |
73a46702 | 2425 | { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, |
77bb000f PP |
2426 | #endif |
2427 | }; | |
2428 | static int exim_openssl_options_size = | |
2429 | sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option); | |
2430 | ||
c80c5570 | 2431 | |
77bb000f PP |
2432 | static BOOL |
2433 | tls_openssl_one_option_parse(uschar *name, long *value) | |
2434 | { | |
2435 | int first = 0; | |
2436 | int last = exim_openssl_options_size; | |
2437 | while (last > first) | |
2438 | { | |
2439 | int middle = (first + last)/2; | |
2440 | int c = Ustrcmp(name, exim_openssl_options[middle].name); | |
2441 | if (c == 0) | |
2442 | { | |
2443 | *value = exim_openssl_options[middle].value; | |
2444 | return TRUE; | |
2445 | } | |
2446 | else if (c > 0) | |
2447 | first = middle + 1; | |
2448 | else | |
2449 | last = middle; | |
2450 | } | |
2451 | return FALSE; | |
2452 | } | |
2453 | ||
2454 | ||
2455 | ||
2456 | ||
2457 | /************************************************* | |
2458 | * OpenSSL option parsing logic * | |
2459 | *************************************************/ | |
2460 | ||
2461 | /* OpenSSL has a number of compatibility options which an administrator might | |
2462 | reasonably wish to set. Interpret a list similarly to decode_bits(), so that | |
2463 | we look like log_selector. | |
2464 | ||
2465 | Arguments: | |
2466 | option_spec the administrator-supplied string of options | |
2467 | results ptr to long storage for the options bitmap | |
2468 | Returns success or failure | |
2469 | */ | |
2470 | ||
2471 | BOOL | |
2472 | tls_openssl_options_parse(uschar *option_spec, long *results) | |
2473 | { | |
2474 | long result, item; | |
2475 | uschar *s, *end; | |
2476 | uschar keep_c; | |
2477 | BOOL adding, item_parsed; | |
2478 | ||
0e944a0d | 2479 | result = 0L; |
b1770b6e | 2480 | /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed |
da3ad30d | 2481 | * from default because it increases BEAST susceptibility. */ |
f0f5a555 PP |
2482 | #ifdef SSL_OP_NO_SSLv2 |
2483 | result |= SSL_OP_NO_SSLv2; | |
2484 | #endif | |
77bb000f PP |
2485 | |
2486 | if (option_spec == NULL) | |
2487 | { | |
2488 | *results = result; | |
2489 | return TRUE; | |
2490 | } | |
2491 | ||
2492 | for (s=option_spec; *s != '\0'; /**/) | |
2493 | { | |
2494 | while (isspace(*s)) ++s; | |
2495 | if (*s == '\0') | |
2496 | break; | |
2497 | if (*s != '+' && *s != '-') | |
2498 | { | |
2499 | DEBUG(D_tls) debug_printf("malformed openssl option setting: " | |
0e944a0d | 2500 | "+ or - expected but found \"%s\"\n", s); |
77bb000f PP |
2501 | return FALSE; |
2502 | } | |
2503 | adding = *s++ == '+'; | |
2504 | for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; | |
2505 | keep_c = *end; | |
2506 | *end = '\0'; | |
2507 | item_parsed = tls_openssl_one_option_parse(s, &item); | |
2508 | if (!item_parsed) | |
2509 | { | |
0e944a0d | 2510 | DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); |
77bb000f PP |
2511 | return FALSE; |
2512 | } | |
2513 | DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n", | |
2514 | adding ? "adding" : "removing", result, item, s); | |
2515 | if (adding) | |
2516 | result |= item; | |
2517 | else | |
2518 | result &= ~item; | |
2519 | *end = keep_c; | |
2520 | s = end; | |
2521 | } | |
2522 | ||
2523 | *results = result; | |
2524 | return TRUE; | |
2525 | } | |
2526 | ||
9d1c15ef JH |
2527 | /* vi: aw ai sw=2 |
2528 | */ | |
059ec3d9 | 2529 | /* End of tls-openssl.c */ |