Commit | Line | Data |
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059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
c4ceed07 | 5 | /* Copyright (c) University of Cambridge 1995 - 2012 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
8 | /* This module provides the TLS (aka SSL) support for Exim using the OpenSSL | |
9 | library. It is #included into the tls.c file when that library is used. The | |
10 | code herein is based on a patch that was originally contributed by Steve | |
11 | Haslam. It was adapted from stunnel, a GPL program by Michal Trojnara. | |
12 | ||
13 | No cryptographic code is included in Exim. All this module does is to call | |
14 | functions from the OpenSSL library. */ | |
15 | ||
16 | ||
17 | /* Heading stuff */ | |
18 | ||
19 | #include <openssl/lhash.h> | |
20 | #include <openssl/ssl.h> | |
21 | #include <openssl/err.h> | |
22 | #include <openssl/rand.h> | |
3f7eeb86 PP |
23 | #ifdef EXPERIMENTAL_OCSP |
24 | #include <openssl/ocsp.h> | |
25 | #endif | |
26 | ||
27 | #ifdef EXPERIMENTAL_OCSP | |
28 | #define EXIM_OCSP_SKEW_SECONDS (300L) | |
29 | #define EXIM_OCSP_MAX_AGE (-1L) | |
30 | #endif | |
059ec3d9 | 31 | |
3bcbbbe2 PP |
32 | #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT) |
33 | #define EXIM_HAVE_OPENSSL_TLSEXT | |
34 | #endif | |
35 | ||
059ec3d9 PH |
36 | /* Structure for collecting random data for seeding. */ |
37 | ||
38 | typedef struct randstuff { | |
9e3331ea TK |
39 | struct timeval tv; |
40 | pid_t p; | |
059ec3d9 PH |
41 | } randstuff; |
42 | ||
43 | /* Local static variables */ | |
44 | ||
a2ff477a JH |
45 | static BOOL client_verify_callback_called = FALSE; |
46 | static BOOL server_verify_callback_called = FALSE; | |
059ec3d9 PH |
47 | static const uschar *sid_ctx = US"exim"; |
48 | ||
d4f09789 PP |
49 | /* We have three different contexts to care about. |
50 | ||
51 | Simple case: client, `client_ctx` | |
52 | As a client, we can be doing a callout or cut-through delivery while receiving | |
53 | a message. So we have a client context, which should have options initialised | |
54 | from the SMTP Transport. | |
55 | ||
56 | Server: | |
57 | There are two cases: with and without ServerNameIndication from the client. | |
58 | Given TLS SNI, we can be using different keys, certs and various other | |
59 | configuration settings, because they're re-expanded with $tls_sni set. This | |
60 | allows vhosting with TLS. This SNI is sent in the handshake. | |
61 | A client might not send SNI, so we need a fallback, and an initial setup too. | |
62 | So as a server, we start out using `server_ctx`. | |
63 | If SNI is sent by the client, then we as server, mid-negotiation, try to clone | |
64 | `server_sni` from `server_ctx` and then initialise settings by re-expanding | |
65 | configuration. | |
66 | */ | |
67 | ||
817d9f57 JH |
68 | static SSL_CTX *client_ctx = NULL; |
69 | static SSL_CTX *server_ctx = NULL; | |
70 | static SSL *client_ssl = NULL; | |
71 | static SSL *server_ssl = NULL; | |
389ca47a | 72 | |
35731706 | 73 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 | 74 | static SSL_CTX *server_sni = NULL; |
35731706 | 75 | #endif |
059ec3d9 PH |
76 | |
77 | static char ssl_errstring[256]; | |
78 | ||
79 | static int ssl_session_timeout = 200; | |
a2ff477a JH |
80 | static BOOL client_verify_optional = FALSE; |
81 | static BOOL server_verify_optional = FALSE; | |
059ec3d9 | 82 | |
7be682ca | 83 | static BOOL reexpand_tls_files_for_sni = FALSE; |
059ec3d9 PH |
84 | |
85 | ||
7be682ca PP |
86 | typedef struct tls_ext_ctx_cb { |
87 | uschar *certificate; | |
88 | uschar *privatekey; | |
3f7eeb86 PP |
89 | #ifdef EXPERIMENTAL_OCSP |
90 | uschar *ocsp_file; | |
91 | uschar *ocsp_file_expanded; | |
92 | OCSP_RESPONSE *ocsp_response; | |
93 | #endif | |
7be682ca PP |
94 | uschar *dhparam; |
95 | /* these are cached from first expand */ | |
96 | uschar *server_cipher_list; | |
97 | /* only passed down to tls_error: */ | |
98 | host_item *host; | |
99 | } tls_ext_ctx_cb; | |
100 | ||
101 | /* should figure out a cleanup of API to handle state preserved per | |
102 | implementation, for various reasons, which can be void * in the APIs. | |
103 | For now, we hack around it. */ | |
817d9f57 JH |
104 | tls_ext_ctx_cb *client_static_cbinfo = NULL; |
105 | tls_ext_ctx_cb *server_static_cbinfo = NULL; | |
7be682ca PP |
106 | |
107 | static int | |
a2ff477a | 108 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, BOOL client); |
059ec3d9 | 109 | |
3f7eeb86 | 110 | /* Callbacks */ |
3bcbbbe2 | 111 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
3f7eeb86 | 112 | static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg); |
3bcbbbe2 | 113 | #endif |
3f7eeb86 PP |
114 | #ifdef EXPERIMENTAL_OCSP |
115 | static int tls_stapling_cb(SSL *s, void *arg); | |
116 | #endif | |
117 | ||
059ec3d9 PH |
118 | |
119 | /************************************************* | |
120 | * Handle TLS error * | |
121 | *************************************************/ | |
122 | ||
123 | /* Called from lots of places when errors occur before actually starting to do | |
124 | the TLS handshake, that is, while the session is still in clear. Always returns | |
125 | DEFER for a server and FAIL for a client so that most calls can use "return | |
126 | tls_error(...)" to do this processing and then give an appropriate return. A | |
127 | single function is used for both server and client, because it is called from | |
128 | some shared functions. | |
129 | ||
130 | Argument: | |
131 | prefix text to include in the logged error | |
132 | host NULL if setting up a server; | |
133 | the connected host if setting up a client | |
7199e1ee | 134 | msg error message or NULL if we should ask OpenSSL |
059ec3d9 PH |
135 | |
136 | Returns: OK/DEFER/FAIL | |
137 | */ | |
138 | ||
139 | static int | |
7199e1ee | 140 | tls_error(uschar *prefix, host_item *host, uschar *msg) |
059ec3d9 | 141 | { |
7199e1ee TF |
142 | if (msg == NULL) |
143 | { | |
144 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
5ca6d115 | 145 | msg = (uschar *)ssl_errstring; |
7199e1ee TF |
146 | } |
147 | ||
059ec3d9 PH |
148 | if (host == NULL) |
149 | { | |
7199e1ee | 150 | uschar *conn_info = smtp_get_connection_info(); |
5ca6d115 | 151 | if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) |
7199e1ee TF |
152 | conn_info += 5; |
153 | log_write(0, LOG_MAIN, "TLS error on %s (%s): %s", | |
154 | conn_info, prefix, msg); | |
059ec3d9 PH |
155 | return DEFER; |
156 | } | |
157 | else | |
158 | { | |
159 | log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s): %s", | |
7199e1ee | 160 | host->name, host->address, prefix, msg); |
059ec3d9 PH |
161 | return FAIL; |
162 | } | |
163 | } | |
164 | ||
165 | ||
166 | ||
167 | /************************************************* | |
168 | * Callback to generate RSA key * | |
169 | *************************************************/ | |
170 | ||
171 | /* | |
172 | Arguments: | |
173 | s SSL connection | |
174 | export not used | |
175 | keylength keylength | |
176 | ||
177 | Returns: pointer to generated key | |
178 | */ | |
179 | ||
180 | static RSA * | |
181 | rsa_callback(SSL *s, int export, int keylength) | |
182 | { | |
183 | RSA *rsa_key; | |
184 | export = export; /* Shut picky compilers up */ | |
185 | DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength); | |
186 | rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL); | |
187 | if (rsa_key == NULL) | |
188 | { | |
189 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
190 | log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s", | |
191 | ssl_errstring); | |
192 | return NULL; | |
193 | } | |
194 | return rsa_key; | |
195 | } | |
196 | ||
197 | ||
198 | ||
199 | ||
200 | /************************************************* | |
201 | * Callback for verification * | |
202 | *************************************************/ | |
203 | ||
204 | /* The SSL library does certificate verification if set up to do so. This | |
205 | callback has the current yes/no state is in "state". If verification succeeded, | |
206 | we set up the tls_peerdn string. If verification failed, what happens depends | |
207 | on whether the client is required to present a verifiable certificate or not. | |
208 | ||
209 | If verification is optional, we change the state to yes, but still log the | |
210 | verification error. For some reason (it really would help to have proper | |
211 | documentation of OpenSSL), this callback function then gets called again, this | |
212 | time with state = 1. In fact, that's useful, because we can set up the peerdn | |
213 | value, but we must take care not to set the private verified flag on the second | |
214 | time through. | |
215 | ||
216 | Note: this function is not called if the client fails to present a certificate | |
217 | when asked. We get here only if a certificate has been received. Handling of | |
218 | optional verification for this case is done when requesting SSL to verify, by | |
219 | setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case. | |
220 | ||
221 | Arguments: | |
222 | state current yes/no state as 1/0 | |
223 | x509ctx certificate information. | |
a2ff477a | 224 | client TRUE for client startup, FALSE for server startup |
059ec3d9 PH |
225 | |
226 | Returns: 1 if verified, 0 if not | |
227 | */ | |
228 | ||
229 | static int | |
a2ff477a | 230 | verify_callback(int state, X509_STORE_CTX *x509ctx, BOOL client) |
059ec3d9 PH |
231 | { |
232 | static uschar txt[256]; | |
a2ff477a JH |
233 | tls_support * tlsp; |
234 | BOOL * calledp; | |
235 | BOOL * optionalp; | |
236 | ||
237 | if (client) | |
238 | { | |
239 | tlsp= &tls_out; | |
240 | calledp= &client_verify_callback_called; | |
241 | optionalp= &client_verify_optional; | |
242 | } | |
243 | else | |
244 | { | |
245 | tlsp= &tls_in; | |
246 | calledp= &server_verify_callback_called; | |
247 | optionalp= &server_verify_optional; | |
248 | } | |
059ec3d9 PH |
249 | |
250 | X509_NAME_oneline(X509_get_subject_name(x509ctx->current_cert), | |
251 | CS txt, sizeof(txt)); | |
252 | ||
253 | if (state == 0) | |
254 | { | |
255 | log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s", | |
256 | x509ctx->error_depth, | |
257 | X509_verify_cert_error_string(x509ctx->error), | |
258 | txt); | |
a2ff477a JH |
259 | tlsp->certificate_verified = FALSE; |
260 | *calledp = TRUE; | |
261 | if (!*optionalp) return 0; /* reject */ | |
059ec3d9 PH |
262 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
263 | "tls_try_verify_hosts)\n"); | |
264 | return 1; /* accept */ | |
265 | } | |
266 | ||
267 | if (x509ctx->error_depth != 0) | |
268 | { | |
269 | DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d cert=%s\n", | |
270 | x509ctx->error_depth, txt); | |
271 | } | |
272 | else | |
273 | { | |
274 | DEBUG(D_tls) debug_printf("SSL%s peer: %s\n", | |
a2ff477a JH |
275 | *calledp ? "" : " authenticated", txt); |
276 | tlsp->peerdn = txt; | |
059ec3d9 PH |
277 | } |
278 | ||
a2ff477a JH |
279 | if (!*calledp) tlsp->certificate_verified = TRUE; |
280 | *calledp = TRUE; | |
059ec3d9 PH |
281 | |
282 | return 1; /* accept */ | |
283 | } | |
284 | ||
a2ff477a JH |
285 | static int |
286 | verify_callback_client(int state, X509_STORE_CTX *x509ctx) | |
287 | { | |
288 | return verify_callback(state, x509ctx, TRUE); | |
289 | } | |
290 | ||
291 | static int | |
292 | verify_callback_server(int state, X509_STORE_CTX *x509ctx) | |
293 | { | |
294 | return verify_callback(state, x509ctx, FALSE); | |
295 | } | |
296 | ||
059ec3d9 PH |
297 | |
298 | ||
299 | /************************************************* | |
300 | * Information callback * | |
301 | *************************************************/ | |
302 | ||
303 | /* The SSL library functions call this from time to time to indicate what they | |
7be682ca PP |
304 | are doing. We copy the string to the debugging output when TLS debugging has |
305 | been requested. | |
059ec3d9 PH |
306 | |
307 | Arguments: | |
308 | s the SSL connection | |
309 | where | |
310 | ret | |
311 | ||
312 | Returns: nothing | |
313 | */ | |
314 | ||
315 | static void | |
316 | info_callback(SSL *s, int where, int ret) | |
317 | { | |
318 | where = where; | |
319 | ret = ret; | |
320 | DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s)); | |
321 | } | |
322 | ||
323 | ||
324 | ||
325 | /************************************************* | |
326 | * Initialize for DH * | |
327 | *************************************************/ | |
328 | ||
329 | /* If dhparam is set, expand it, and load up the parameters for DH encryption. | |
330 | ||
331 | Arguments: | |
a799883d | 332 | dhparam DH parameter file or fixed parameter identity string |
7199e1ee | 333 | host connected host, if client; NULL if server |
059ec3d9 PH |
334 | |
335 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
336 | */ | |
337 | ||
338 | static BOOL | |
a799883d | 339 | init_dh(SSL_CTX *sctx, uschar *dhparam, host_item *host) |
059ec3d9 | 340 | { |
059ec3d9 PH |
341 | BIO *bio; |
342 | DH *dh; | |
343 | uschar *dhexpanded; | |
a799883d | 344 | const char *pem; |
059ec3d9 PH |
345 | |
346 | if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded)) | |
347 | return FALSE; | |
348 | ||
a799883d | 349 | if (dhexpanded == NULL || *dhexpanded == '\0') |
059ec3d9 | 350 | { |
a799883d | 351 | bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1); |
059ec3d9 | 352 | } |
a799883d | 353 | else if (dhexpanded[0] == '/') |
059ec3d9 | 354 | { |
a799883d PP |
355 | bio = BIO_new_file(CS dhexpanded, "r"); |
356 | if (bio == NULL) | |
059ec3d9 | 357 | { |
7199e1ee | 358 | tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), |
a799883d PP |
359 | host, US strerror(errno)); |
360 | return FALSE; | |
059ec3d9 | 361 | } |
a799883d PP |
362 | } |
363 | else | |
364 | { | |
365 | if (Ustrcmp(dhexpanded, "none") == 0) | |
059ec3d9 | 366 | { |
a799883d PP |
367 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); |
368 | return TRUE; | |
059ec3d9 | 369 | } |
a799883d PP |
370 | |
371 | pem = std_dh_prime_named(dhexpanded); | |
372 | if (!pem) | |
373 | { | |
374 | tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded), | |
375 | host, US strerror(errno)); | |
376 | return FALSE; | |
377 | } | |
378 | bio = BIO_new_mem_buf(CS pem, -1); | |
379 | } | |
380 | ||
381 | dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL); | |
382 | if (dh == NULL) | |
383 | { | |
059ec3d9 | 384 | BIO_free(bio); |
a799883d PP |
385 | tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded), |
386 | host, NULL); | |
387 | return FALSE; | |
388 | } | |
389 | ||
390 | /* Even if it is larger, we silently return success rather than cause things | |
391 | * to fail out, so that a too-large DH will not knock out all TLS; it's a | |
392 | * debatable choice. */ | |
393 | if ((8*DH_size(dh)) > tls_dh_max_bits) | |
394 | { | |
395 | DEBUG(D_tls) | |
396 | debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d", | |
397 | 8*DH_size(dh), tls_dh_max_bits); | |
398 | } | |
399 | else | |
400 | { | |
401 | SSL_CTX_set_tmp_dh(sctx, dh); | |
402 | DEBUG(D_tls) | |
403 | debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n", | |
404 | dhexpanded ? dhexpanded : US"default", 8*DH_size(dh)); | |
059ec3d9 PH |
405 | } |
406 | ||
a799883d PP |
407 | DH_free(dh); |
408 | BIO_free(bio); | |
409 | ||
410 | return TRUE; | |
059ec3d9 PH |
411 | } |
412 | ||
413 | ||
414 | ||
415 | ||
3f7eeb86 PP |
416 | #ifdef EXPERIMENTAL_OCSP |
417 | /************************************************* | |
418 | * Load OCSP information into state * | |
419 | *************************************************/ | |
420 | ||
421 | /* Called to load the OCSP response from the given file into memory, once | |
422 | caller has determined this is needed. Checks validity. Debugs a message | |
423 | if invalid. | |
424 | ||
425 | ASSUMES: single response, for single cert. | |
426 | ||
427 | Arguments: | |
428 | sctx the SSL_CTX* to update | |
429 | cbinfo various parts of session state | |
430 | expanded the filename putatively holding an OCSP response | |
431 | ||
432 | */ | |
433 | ||
434 | static void | |
435 | ocsp_load_response(SSL_CTX *sctx, | |
436 | tls_ext_ctx_cb *cbinfo, | |
437 | const uschar *expanded) | |
438 | { | |
439 | BIO *bio; | |
440 | OCSP_RESPONSE *resp; | |
441 | OCSP_BASICRESP *basic_response; | |
442 | OCSP_SINGLERESP *single_response; | |
443 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
444 | X509_STORE *store; | |
445 | unsigned long verify_flags; | |
446 | int status, reason, i; | |
447 | ||
448 | cbinfo->ocsp_file_expanded = string_copy(expanded); | |
449 | if (cbinfo->ocsp_response) | |
450 | { | |
451 | OCSP_RESPONSE_free(cbinfo->ocsp_response); | |
452 | cbinfo->ocsp_response = NULL; | |
453 | } | |
454 | ||
455 | bio = BIO_new_file(CS cbinfo->ocsp_file_expanded, "rb"); | |
456 | if (!bio) | |
457 | { | |
458 | DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", | |
459 | cbinfo->ocsp_file_expanded); | |
460 | return; | |
461 | } | |
462 | ||
463 | resp = d2i_OCSP_RESPONSE_bio(bio, NULL); | |
464 | BIO_free(bio); | |
465 | if (!resp) | |
466 | { | |
467 | DEBUG(D_tls) debug_printf("Error reading OCSP response.\n"); | |
468 | return; | |
469 | } | |
470 | ||
471 | status = OCSP_response_status(resp); | |
472 | if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) | |
473 | { | |
474 | DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", | |
475 | OCSP_response_status_str(status), status); | |
476 | return; | |
477 | } | |
478 | ||
479 | basic_response = OCSP_response_get1_basic(resp); | |
480 | if (!basic_response) | |
481 | { | |
482 | DEBUG(D_tls) | |
483 | debug_printf("OCSP response parse error: unable to extract basic response.\n"); | |
484 | return; | |
485 | } | |
486 | ||
487 | store = SSL_CTX_get_cert_store(sctx); | |
488 | verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ | |
489 | ||
490 | /* May need to expose ability to adjust those flags? | |
491 | OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT | |
492 | OCSP_TRUSTOTHER OCSP_NOINTERN */ | |
493 | ||
494 | i = OCSP_basic_verify(basic_response, NULL, store, verify_flags); | |
495 | if (i <= 0) | |
496 | { | |
497 | DEBUG(D_tls) { | |
498 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
499 | debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); | |
500 | } | |
501 | return; | |
502 | } | |
503 | ||
504 | /* Here's the simplifying assumption: there's only one response, for the | |
505 | one certificate we use, and nothing for anything else in a chain. If this | |
506 | proves false, we need to extract a cert id from our issued cert | |
507 | (tls_certificate) and use that for OCSP_resp_find_status() (which finds the | |
508 | right cert in the stack and then calls OCSP_single_get0_status()). | |
509 | ||
510 | I'm hoping to avoid reworking a bunch more of how we handle state here. */ | |
511 | single_response = OCSP_resp_get0(basic_response, 0); | |
512 | if (!single_response) | |
513 | { | |
514 | DEBUG(D_tls) | |
515 | debug_printf("Unable to get first response from OCSP basic response.\n"); | |
516 | return; | |
517 | } | |
518 | ||
519 | status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd); | |
520 | /* how does this status differ from the one above? */ | |
521 | if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) | |
522 | { | |
523 | DEBUG(D_tls) debug_printf("OCSP response not valid (take 2): %s (%d)\n", | |
524 | OCSP_response_status_str(status), status); | |
525 | return; | |
526 | } | |
527 | ||
528 | if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
529 | { | |
530 | DEBUG(D_tls) debug_printf("OCSP status invalid times.\n"); | |
531 | return; | |
532 | } | |
533 | ||
534 | cbinfo->ocsp_response = resp; | |
535 | } | |
536 | #endif | |
537 | ||
538 | ||
539 | ||
540 | ||
7be682ca PP |
541 | /************************************************* |
542 | * Expand key and cert file specs * | |
543 | *************************************************/ | |
544 | ||
545 | /* Called once during tls_init and possibly againt during TLS setup, for a | |
546 | new context, if Server Name Indication was used and tls_sni was seen in | |
547 | the certificate string. | |
548 | ||
549 | Arguments: | |
550 | sctx the SSL_CTX* to update | |
551 | cbinfo various parts of session state | |
552 | ||
553 | Returns: OK/DEFER/FAIL | |
554 | */ | |
555 | ||
556 | static int | |
3f7eeb86 | 557 | tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo) |
7be682ca PP |
558 | { |
559 | uschar *expanded; | |
560 | ||
561 | if (cbinfo->certificate == NULL) | |
562 | return OK; | |
563 | ||
d9b2312b JH |
564 | if (Ustrstr(cbinfo->certificate, US"tls_sni") || |
565 | Ustrstr(cbinfo->certificate, US"tls_in_sni") || | |
566 | Ustrstr(cbinfo->certificate, US"tls_out_sni") | |
567 | ) | |
7be682ca PP |
568 | reexpand_tls_files_for_sni = TRUE; |
569 | ||
570 | if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded)) | |
571 | return DEFER; | |
572 | ||
573 | if (expanded != NULL) | |
574 | { | |
575 | DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); | |
576 | if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded)) | |
577 | return tls_error(string_sprintf( | |
578 | "SSL_CTX_use_certificate_chain_file file=%s", expanded), | |
579 | cbinfo->host, NULL); | |
580 | } | |
581 | ||
582 | if (cbinfo->privatekey != NULL && | |
583 | !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded)) | |
584 | return DEFER; | |
585 | ||
586 | /* If expansion was forced to fail, key_expanded will be NULL. If the result | |
587 | of the expansion is an empty string, ignore it also, and assume the private | |
588 | key is in the same file as the certificate. */ | |
589 | ||
590 | if (expanded != NULL && *expanded != 0) | |
591 | { | |
592 | DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); | |
593 | if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM)) | |
594 | return tls_error(string_sprintf( | |
595 | "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL); | |
596 | } | |
597 | ||
3f7eeb86 PP |
598 | #ifdef EXPERIMENTAL_OCSP |
599 | if (cbinfo->ocsp_file != NULL) | |
600 | { | |
601 | if (!expand_check(cbinfo->ocsp_file, US"tls_ocsp_file", &expanded)) | |
602 | return DEFER; | |
603 | ||
604 | if (expanded != NULL && *expanded != 0) | |
605 | { | |
606 | DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded); | |
607 | if (cbinfo->ocsp_file_expanded && | |
608 | (Ustrcmp(expanded, cbinfo->ocsp_file_expanded) == 0)) | |
609 | { | |
610 | DEBUG(D_tls) | |
611 | debug_printf("tls_ocsp_file value unchanged, using existing values.\n"); | |
612 | } else { | |
613 | ocsp_load_response(sctx, cbinfo, expanded); | |
614 | } | |
615 | } | |
616 | } | |
617 | #endif | |
618 | ||
7be682ca PP |
619 | return OK; |
620 | } | |
621 | ||
622 | ||
623 | ||
624 | ||
625 | /************************************************* | |
626 | * Callback to handle SNI * | |
627 | *************************************************/ | |
628 | ||
629 | /* Called when acting as server during the TLS session setup if a Server Name | |
630 | Indication extension was sent by the client. | |
631 | ||
632 | API documentation is OpenSSL s_server.c implementation. | |
633 | ||
634 | Arguments: | |
635 | s SSL* of the current session | |
636 | ad unknown (part of OpenSSL API) (unused) | |
637 | arg Callback of "our" registered data | |
638 | ||
639 | Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK} | |
640 | */ | |
641 | ||
3bcbbbe2 | 642 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
7be682ca PP |
643 | static int |
644 | tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg) | |
645 | { | |
646 | const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); | |
3f7eeb86 | 647 | tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; |
7be682ca | 648 | int rc; |
3f0945ff | 649 | int old_pool = store_pool; |
7be682ca PP |
650 | |
651 | if (!servername) | |
652 | return SSL_TLSEXT_ERR_OK; | |
653 | ||
3f0945ff | 654 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername, |
7be682ca PP |
655 | reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)"); |
656 | ||
657 | /* Make the extension value available for expansion */ | |
3f0945ff | 658 | store_pool = POOL_PERM; |
817d9f57 | 659 | tls_in.sni = string_copy(US servername); |
3f0945ff | 660 | store_pool = old_pool; |
7be682ca PP |
661 | |
662 | if (!reexpand_tls_files_for_sni) | |
663 | return SSL_TLSEXT_ERR_OK; | |
664 | ||
665 | /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually; | |
666 | not confident that memcpy wouldn't break some internal reference counting. | |
667 | Especially since there's a references struct member, which would be off. */ | |
668 | ||
817d9f57 JH |
669 | server_sni = SSL_CTX_new(SSLv23_server_method()); |
670 | if (!server_sni) | |
7be682ca PP |
671 | { |
672 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
673 | DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring); | |
674 | return SSL_TLSEXT_ERR_NOACK; | |
675 | } | |
676 | ||
677 | /* Not sure how many of these are actually needed, since SSL object | |
678 | already exists. Might even need this selfsame callback, for reneg? */ | |
679 | ||
817d9f57 JH |
680 | SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx)); |
681 | SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx)); | |
682 | SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); | |
683 | SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); | |
684 | SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); | |
685 | SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); | |
7be682ca | 686 | if (cbinfo->server_cipher_list) |
817d9f57 | 687 | SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list); |
3f7eeb86 PP |
688 | #ifdef EXPERIMENTAL_OCSP |
689 | if (cbinfo->ocsp_file) | |
690 | { | |
817d9f57 | 691 | SSL_CTX_set_tlsext_status_cb(server_sni, tls_stapling_cb); |
5e55c7a9 | 692 | SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo); |
3f7eeb86 PP |
693 | } |
694 | #endif | |
7be682ca | 695 | |
a2ff477a | 696 | rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, FALSE); |
7be682ca PP |
697 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
698 | ||
3f7eeb86 PP |
699 | /* do this after setup_certs, because this can require the certs for verifying |
700 | OCSP information. */ | |
817d9f57 | 701 | rc = tls_expand_session_files(server_sni, cbinfo); |
7be682ca PP |
702 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
703 | ||
389ca47a | 704 | rc = init_dh(server_sni, cbinfo->dhparam, NULL); |
a799883d PP |
705 | if (rc != OK) return SSL_TLSEXT_ERR_NOACK; |
706 | ||
7be682ca | 707 | DEBUG(D_tls) debug_printf("Switching SSL context.\n"); |
817d9f57 | 708 | SSL_set_SSL_CTX(s, server_sni); |
7be682ca PP |
709 | |
710 | return SSL_TLSEXT_ERR_OK; | |
711 | } | |
3bcbbbe2 | 712 | #endif /* EXIM_HAVE_OPENSSL_TLSEXT */ |
7be682ca PP |
713 | |
714 | ||
715 | ||
716 | ||
3f7eeb86 PP |
717 | #ifdef EXPERIMENTAL_OCSP |
718 | /************************************************* | |
719 | * Callback to handle OCSP Stapling * | |
720 | *************************************************/ | |
721 | ||
722 | /* Called when acting as server during the TLS session setup if the client | |
723 | requests OCSP information with a Certificate Status Request. | |
724 | ||
725 | Documentation via openssl s_server.c and the Apache patch from the OpenSSL | |
726 | project. | |
727 | ||
728 | */ | |
729 | ||
730 | static int | |
731 | tls_stapling_cb(SSL *s, void *arg) | |
732 | { | |
733 | const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; | |
734 | uschar *response_der; | |
735 | int response_der_len; | |
736 | ||
737 | DEBUG(D_tls) debug_printf("Received TLS status request (OCSP stapling); %s response.\n", | |
738 | cbinfo->ocsp_response ? "have" : "lack"); | |
739 | if (!cbinfo->ocsp_response) | |
740 | return SSL_TLSEXT_ERR_NOACK; | |
741 | ||
742 | response_der = NULL; | |
743 | response_der_len = i2d_OCSP_RESPONSE(cbinfo->ocsp_response, &response_der); | |
744 | if (response_der_len <= 0) | |
745 | return SSL_TLSEXT_ERR_NOACK; | |
746 | ||
5e55c7a9 | 747 | SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len); |
3f7eeb86 PP |
748 | return SSL_TLSEXT_ERR_OK; |
749 | } | |
750 | ||
751 | #endif /* EXPERIMENTAL_OCSP */ | |
752 | ||
753 | ||
754 | ||
755 | ||
059ec3d9 PH |
756 | /************************************************* |
757 | * Initialize for TLS * | |
758 | *************************************************/ | |
759 | ||
760 | /* Called from both server and client code, to do preliminary initialization of | |
761 | the library. | |
762 | ||
763 | Arguments: | |
764 | host connected host, if client; NULL if server | |
765 | dhparam DH parameter file | |
766 | certificate certificate file | |
767 | privatekey private key | |
768 | addr address if client; NULL if server (for some randomness) | |
769 | ||
770 | Returns: OK/DEFER/FAIL | |
771 | */ | |
772 | ||
773 | static int | |
817d9f57 | 774 | tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate, |
3f7eeb86 PP |
775 | uschar *privatekey, |
776 | #ifdef EXPERIMENTAL_OCSP | |
777 | uschar *ocsp_file, | |
778 | #endif | |
817d9f57 | 779 | address_item *addr, tls_ext_ctx_cb ** cbp) |
059ec3d9 | 780 | { |
77bb000f | 781 | long init_options; |
7be682ca | 782 | int rc; |
77bb000f | 783 | BOOL okay; |
7be682ca PP |
784 | tls_ext_ctx_cb *cbinfo; |
785 | ||
786 | cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); | |
787 | cbinfo->certificate = certificate; | |
788 | cbinfo->privatekey = privatekey; | |
3f7eeb86 PP |
789 | #ifdef EXPERIMENTAL_OCSP |
790 | cbinfo->ocsp_file = ocsp_file; | |
791 | #endif | |
7be682ca PP |
792 | cbinfo->dhparam = dhparam; |
793 | cbinfo->host = host; | |
77bb000f | 794 | |
059ec3d9 PH |
795 | SSL_load_error_strings(); /* basic set up */ |
796 | OpenSSL_add_ssl_algorithms(); | |
797 | ||
388d6564 | 798 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) |
77bb000f | 799 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the |
a0475b69 TK |
800 | list of available digests. */ |
801 | EVP_add_digest(EVP_sha256()); | |
cf1ef1a9 | 802 | #endif |
a0475b69 | 803 | |
f0f5a555 PP |
804 | /* Create a context. |
805 | The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant | |
806 | negotiation in the different methods; as far as I can tell, the only | |
807 | *_{server,client}_method which allows negotiation is SSLv23, which exists even | |
808 | when OpenSSL is built without SSLv2 support. | |
809 | By disabling with openssl_options, we can let admins re-enable with the | |
810 | existing knob. */ | |
059ec3d9 | 811 | |
817d9f57 | 812 | *ctxp = SSL_CTX_new((host == NULL)? |
059ec3d9 PH |
813 | SSLv23_server_method() : SSLv23_client_method()); |
814 | ||
817d9f57 | 815 | if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL); |
059ec3d9 PH |
816 | |
817 | /* It turns out that we need to seed the random number generator this early in | |
818 | order to get the full complement of ciphers to work. It took me roughly a day | |
819 | of work to discover this by experiment. | |
820 | ||
821 | On systems that have /dev/urandom, SSL may automatically seed itself from | |
822 | there. Otherwise, we have to make something up as best we can. Double check | |
823 | afterwards. */ | |
824 | ||
825 | if (!RAND_status()) | |
826 | { | |
827 | randstuff r; | |
9e3331ea | 828 | gettimeofday(&r.tv, NULL); |
059ec3d9 PH |
829 | r.p = getpid(); |
830 | ||
831 | RAND_seed((uschar *)(&r), sizeof(r)); | |
832 | RAND_seed((uschar *)big_buffer, big_buffer_size); | |
833 | if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr)); | |
834 | ||
835 | if (!RAND_status()) | |
7199e1ee | 836 | return tls_error(US"RAND_status", host, |
5ca6d115 | 837 | US"unable to seed random number generator"); |
059ec3d9 PH |
838 | } |
839 | ||
840 | /* Set up the information callback, which outputs if debugging is at a suitable | |
841 | level. */ | |
842 | ||
817d9f57 | 843 | SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback); |
059ec3d9 | 844 | |
c80c5570 | 845 | /* Automatically re-try reads/writes after renegotiation. */ |
817d9f57 | 846 | (void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY); |
c80c5570 | 847 | |
77bb000f PP |
848 | /* Apply administrator-supplied work-arounds. |
849 | Historically we applied just one requested option, | |
850 | SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we | |
851 | moved to an administrator-controlled list of options to specify and | |
852 | grandfathered in the first one as the default value for "openssl_options". | |
059ec3d9 | 853 | |
77bb000f PP |
854 | No OpenSSL version number checks: the options we accept depend upon the |
855 | availability of the option value macros from OpenSSL. */ | |
059ec3d9 | 856 | |
77bb000f PP |
857 | okay = tls_openssl_options_parse(openssl_options, &init_options); |
858 | if (!okay) | |
73a46702 | 859 | return tls_error(US"openssl_options parsing failed", host, NULL); |
77bb000f PP |
860 | |
861 | if (init_options) | |
862 | { | |
863 | DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); | |
817d9f57 | 864 | if (!(SSL_CTX_set_options(*ctxp, init_options))) |
77bb000f PP |
865 | return tls_error(string_sprintf( |
866 | "SSL_CTX_set_option(%#lx)", init_options), host, NULL); | |
867 | } | |
868 | else | |
869 | DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); | |
059ec3d9 PH |
870 | |
871 | /* Initialize with DH parameters if supplied */ | |
872 | ||
817d9f57 | 873 | if (!init_dh(*ctxp, dhparam, host)) return DEFER; |
059ec3d9 | 874 | |
3f7eeb86 | 875 | /* Set up certificate and key (and perhaps OCSP info) */ |
059ec3d9 | 876 | |
817d9f57 | 877 | rc = tls_expand_session_files(*ctxp, cbinfo); |
7be682ca | 878 | if (rc != OK) return rc; |
c91535f3 | 879 | |
7be682ca | 880 | /* If we need to handle SNI, do so */ |
3bcbbbe2 | 881 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
3f0945ff PP |
882 | if (host == NULL) |
883 | { | |
3f7eeb86 PP |
884 | #ifdef EXPERIMENTAL_OCSP |
885 | /* We check ocsp_file, not ocsp_response, because we care about if | |
886 | the option exists, not what the current expansion might be, as SNI might | |
887 | change the certificate and OCSP file in use between now and the time the | |
888 | callback is invoked. */ | |
889 | if (cbinfo->ocsp_file) | |
890 | { | |
5e55c7a9 PP |
891 | SSL_CTX_set_tlsext_status_cb(server_ctx, tls_stapling_cb); |
892 | SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo); | |
3f7eeb86 PP |
893 | } |
894 | #endif | |
3f0945ff PP |
895 | /* We always do this, so that $tls_sni is available even if not used in |
896 | tls_certificate */ | |
817d9f57 JH |
897 | SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb); |
898 | SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo); | |
3f0945ff | 899 | } |
7be682ca | 900 | #endif |
059ec3d9 PH |
901 | |
902 | /* Set up the RSA callback */ | |
903 | ||
817d9f57 | 904 | SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback); |
059ec3d9 PH |
905 | |
906 | /* Finally, set the timeout, and we are done */ | |
907 | ||
817d9f57 | 908 | SSL_CTX_set_timeout(*ctxp, ssl_session_timeout); |
059ec3d9 | 909 | DEBUG(D_tls) debug_printf("Initialized TLS\n"); |
7be682ca | 910 | |
817d9f57 | 911 | *cbp = cbinfo; |
7be682ca | 912 | |
059ec3d9 PH |
913 | return OK; |
914 | } | |
915 | ||
916 | ||
917 | ||
918 | ||
919 | /************************************************* | |
920 | * Get name of cipher in use * | |
921 | *************************************************/ | |
922 | ||
817d9f57 | 923 | /* |
059ec3d9 | 924 | Argument: pointer to an SSL structure for the connection |
817d9f57 JH |
925 | buffer to use for answer |
926 | size of buffer | |
927 | pointer to number of bits for cipher | |
059ec3d9 PH |
928 | Returns: nothing |
929 | */ | |
930 | ||
931 | static void | |
817d9f57 | 932 | construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits) |
059ec3d9 | 933 | { |
57b3a7f5 PP |
934 | /* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't |
935 | yet reflect that. It should be a safe change anyway, even 0.9.8 versions have | |
936 | the accessor functions use const in the prototype. */ | |
937 | const SSL_CIPHER *c; | |
059ec3d9 | 938 | uschar *ver; |
059ec3d9 PH |
939 | |
940 | switch (ssl->session->ssl_version) | |
941 | { | |
942 | case SSL2_VERSION: | |
943 | ver = US"SSLv2"; | |
944 | break; | |
945 | ||
946 | case SSL3_VERSION: | |
947 | ver = US"SSLv3"; | |
948 | break; | |
949 | ||
950 | case TLS1_VERSION: | |
951 | ver = US"TLSv1"; | |
952 | break; | |
953 | ||
c80c5570 PP |
954 | #ifdef TLS1_1_VERSION |
955 | case TLS1_1_VERSION: | |
956 | ver = US"TLSv1.1"; | |
957 | break; | |
958 | #endif | |
959 | ||
960 | #ifdef TLS1_2_VERSION | |
961 | case TLS1_2_VERSION: | |
962 | ver = US"TLSv1.2"; | |
963 | break; | |
964 | #endif | |
965 | ||
059ec3d9 PH |
966 | default: |
967 | ver = US"UNKNOWN"; | |
968 | } | |
969 | ||
57b3a7f5 | 970 | c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); |
817d9f57 | 971 | SSL_CIPHER_get_bits(c, bits); |
059ec3d9 | 972 | |
817d9f57 JH |
973 | string_format(cipherbuf, bsize, "%s:%s:%u", ver, |
974 | SSL_CIPHER_get_name(c), *bits); | |
059ec3d9 PH |
975 | |
976 | DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf); | |
977 | } | |
978 | ||
979 | ||
980 | ||
981 | ||
982 | ||
983 | /************************************************* | |
984 | * Set up for verifying certificates * | |
985 | *************************************************/ | |
986 | ||
987 | /* Called by both client and server startup | |
988 | ||
989 | Arguments: | |
7be682ca | 990 | sctx SSL_CTX* to initialise |
059ec3d9 PH |
991 | certs certs file or NULL |
992 | crl CRL file or NULL | |
993 | host NULL in a server; the remote host in a client | |
994 | optional TRUE if called from a server for a host in tls_try_verify_hosts; | |
995 | otherwise passed as FALSE | |
a2ff477a | 996 | client TRUE if called for client startup, FALSE for server startup |
059ec3d9 PH |
997 | |
998 | Returns: OK/DEFER/FAIL | |
999 | */ | |
1000 | ||
1001 | static int | |
a2ff477a | 1002 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, BOOL client) |
059ec3d9 PH |
1003 | { |
1004 | uschar *expcerts, *expcrl; | |
1005 | ||
1006 | if (!expand_check(certs, US"tls_verify_certificates", &expcerts)) | |
1007 | return DEFER; | |
1008 | ||
1009 | if (expcerts != NULL) | |
1010 | { | |
1011 | struct stat statbuf; | |
7be682ca | 1012 | if (!SSL_CTX_set_default_verify_paths(sctx)) |
7199e1ee | 1013 | return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL); |
059ec3d9 PH |
1014 | |
1015 | if (Ustat(expcerts, &statbuf) < 0) | |
1016 | { | |
1017 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1018 | "failed to stat %s for certificates", expcerts); | |
1019 | return DEFER; | |
1020 | } | |
1021 | else | |
1022 | { | |
1023 | uschar *file, *dir; | |
1024 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
1025 | { file = NULL; dir = expcerts; } | |
1026 | else | |
1027 | { file = expcerts; dir = NULL; } | |
1028 | ||
1029 | /* If a certificate file is empty, the next function fails with an | |
1030 | unhelpful error message. If we skip it, we get the correct behaviour (no | |
1031 | certificates are recognized, but the error message is still misleading (it | |
1032 | says no certificate was supplied.) But this is better. */ | |
1033 | ||
1034 | if ((file == NULL || statbuf.st_size > 0) && | |
7be682ca | 1035 | !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) |
7199e1ee | 1036 | return tls_error(US"SSL_CTX_load_verify_locations", host, NULL); |
059ec3d9 PH |
1037 | |
1038 | if (file != NULL) | |
1039 | { | |
7be682ca | 1040 | SSL_CTX_set_client_CA_list(sctx, SSL_load_client_CA_file(CS file)); |
059ec3d9 PH |
1041 | } |
1042 | } | |
1043 | ||
1044 | /* Handle a certificate revocation list. */ | |
1045 | ||
1046 | #if OPENSSL_VERSION_NUMBER > 0x00907000L | |
1047 | ||
8b417f2c PH |
1048 | /* This bit of code is now the version supplied by Lars Mainka. (I have |
1049 | * merely reformatted it into the Exim code style.) | |
1050 | ||
1051 | * "From here I changed the code to add support for multiple crl's | |
1052 | * in pem format in one file or to support hashed directory entries in | |
1053 | * pem format instead of a file. This method now uses the library function | |
1054 | * X509_STORE_load_locations to add the CRL location to the SSL context. | |
1055 | * OpenSSL will then handle the verify against CA certs and CRLs by | |
1056 | * itself in the verify callback." */ | |
1057 | ||
059ec3d9 PH |
1058 | if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER; |
1059 | if (expcrl != NULL && *expcrl != 0) | |
1060 | { | |
8b417f2c PH |
1061 | struct stat statbufcrl; |
1062 | if (Ustat(expcrl, &statbufcrl) < 0) | |
1063 | { | |
1064 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1065 | "failed to stat %s for certificates revocation lists", expcrl); | |
1066 | return DEFER; | |
1067 | } | |
1068 | else | |
059ec3d9 | 1069 | { |
8b417f2c PH |
1070 | /* is it a file or directory? */ |
1071 | uschar *file, *dir; | |
7be682ca | 1072 | X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx); |
8b417f2c | 1073 | if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR) |
059ec3d9 | 1074 | { |
8b417f2c PH |
1075 | file = NULL; |
1076 | dir = expcrl; | |
1077 | DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir); | |
059ec3d9 PH |
1078 | } |
1079 | else | |
1080 | { | |
8b417f2c PH |
1081 | file = expcrl; |
1082 | dir = NULL; | |
1083 | DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); | |
059ec3d9 | 1084 | } |
8b417f2c | 1085 | if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) |
7199e1ee | 1086 | return tls_error(US"X509_STORE_load_locations", host, NULL); |
8b417f2c PH |
1087 | |
1088 | /* setting the flags to check against the complete crl chain */ | |
1089 | ||
1090 | X509_STORE_set_flags(cvstore, | |
1091 | X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL); | |
059ec3d9 | 1092 | } |
059ec3d9 PH |
1093 | } |
1094 | ||
1095 | #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ | |
1096 | ||
1097 | /* If verification is optional, don't fail if no certificate */ | |
1098 | ||
7be682ca | 1099 | SSL_CTX_set_verify(sctx, |
059ec3d9 | 1100 | SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT), |
a2ff477a | 1101 | client ? verify_callback_client : verify_callback_server); |
059ec3d9 PH |
1102 | } |
1103 | ||
1104 | return OK; | |
1105 | } | |
1106 | ||
1107 | ||
1108 | ||
1109 | /************************************************* | |
1110 | * Start a TLS session in a server * | |
1111 | *************************************************/ | |
1112 | ||
1113 | /* This is called when Exim is running as a server, after having received | |
1114 | the STARTTLS command. It must respond to that command, and then negotiate | |
1115 | a TLS session. | |
1116 | ||
1117 | Arguments: | |
1118 | require_ciphers allowed ciphers | |
1119 | ||
1120 | Returns: OK on success | |
1121 | DEFER for errors before the start of the negotiation | |
1122 | FAIL for errors during the negotation; the server can't | |
1123 | continue running. | |
1124 | */ | |
1125 | ||
1126 | int | |
17c76198 | 1127 | tls_server_start(const uschar *require_ciphers) |
059ec3d9 PH |
1128 | { |
1129 | int rc; | |
1130 | uschar *expciphers; | |
7be682ca | 1131 | tls_ext_ctx_cb *cbinfo; |
817d9f57 | 1132 | static uschar cipherbuf[256]; |
059ec3d9 PH |
1133 | |
1134 | /* Check for previous activation */ | |
1135 | ||
817d9f57 | 1136 | if (tls_in.active >= 0) |
059ec3d9 | 1137 | { |
5ca6d115 | 1138 | tls_error(US"STARTTLS received after TLS started", NULL, US""); |
059ec3d9 PH |
1139 | smtp_printf("554 Already in TLS\r\n"); |
1140 | return FAIL; | |
1141 | } | |
1142 | ||
1143 | /* Initialize the SSL library. If it fails, it will already have logged | |
1144 | the error. */ | |
1145 | ||
817d9f57 | 1146 | rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey, |
3f7eeb86 PP |
1147 | #ifdef EXPERIMENTAL_OCSP |
1148 | tls_ocsp_file, | |
1149 | #endif | |
817d9f57 | 1150 | NULL, &server_static_cbinfo); |
059ec3d9 | 1151 | if (rc != OK) return rc; |
817d9f57 | 1152 | cbinfo = server_static_cbinfo; |
059ec3d9 PH |
1153 | |
1154 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers)) | |
1155 | return FAIL; | |
1156 | ||
1157 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
17c76198 PP |
1158 | were historically separated by underscores. So that I can use either form in my |
1159 | tests, and also for general convenience, we turn underscores into hyphens here. | |
1160 | */ | |
059ec3d9 PH |
1161 | |
1162 | if (expciphers != NULL) | |
1163 | { | |
1164 | uschar *s = expciphers; | |
1165 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1166 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1167 | if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) |
7199e1ee | 1168 | return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL); |
7be682ca | 1169 | cbinfo->server_cipher_list = expciphers; |
059ec3d9 PH |
1170 | } |
1171 | ||
1172 | /* If this is a host for which certificate verification is mandatory or | |
1173 | optional, set up appropriately. */ | |
1174 | ||
817d9f57 | 1175 | tls_in.certificate_verified = FALSE; |
a2ff477a | 1176 | server_verify_callback_called = FALSE; |
059ec3d9 PH |
1177 | |
1178 | if (verify_check_host(&tls_verify_hosts) == OK) | |
1179 | { | |
a2ff477a | 1180 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, FALSE, FALSE); |
059ec3d9 | 1181 | if (rc != OK) return rc; |
a2ff477a | 1182 | server_verify_optional = FALSE; |
059ec3d9 PH |
1183 | } |
1184 | else if (verify_check_host(&tls_try_verify_hosts) == OK) | |
1185 | { | |
a2ff477a | 1186 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, TRUE, FALSE); |
059ec3d9 | 1187 | if (rc != OK) return rc; |
a2ff477a | 1188 | server_verify_optional = TRUE; |
059ec3d9 PH |
1189 | } |
1190 | ||
1191 | /* Prepare for new connection */ | |
1192 | ||
817d9f57 | 1193 | if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL); |
da3ad30d PP |
1194 | |
1195 | /* Warning: we used to SSL_clear(ssl) here, it was removed. | |
1196 | * | |
1197 | * With the SSL_clear(), we get strange interoperability bugs with | |
1198 | * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in | |
1199 | * OpenSSL itself, as a clear should not lead to inability to follow protocols. | |
1200 | * | |
1201 | * The SSL_clear() call is to let an existing SSL* be reused, typically after | |
1202 | * session shutdown. In this case, we have a brand new object and there's no | |
1203 | * obvious reason to immediately clear it. I'm guessing that this was | |
1204 | * originally added because of incomplete initialisation which the clear fixed, | |
1205 | * in some historic release. | |
1206 | */ | |
059ec3d9 PH |
1207 | |
1208 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
1209 | on connection, where outputting anything now upsets the clients and tends to | |
1210 | make them disconnect. We need to have an explicit fflush() here, to force out | |
1211 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
1212 | mode, the fflush() happens when smtp_getc() is called. */ | |
1213 | ||
817d9f57 JH |
1214 | SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx)); |
1215 | if (!tls_in.on_connect) | |
059ec3d9 PH |
1216 | { |
1217 | smtp_printf("220 TLS go ahead\r\n"); | |
1218 | fflush(smtp_out); | |
1219 | } | |
1220 | ||
1221 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
1222 | that the OpenSSL library doesn't. */ | |
1223 | ||
817d9f57 JH |
1224 | SSL_set_wfd(server_ssl, fileno(smtp_out)); |
1225 | SSL_set_rfd(server_ssl, fileno(smtp_in)); | |
1226 | SSL_set_accept_state(server_ssl); | |
059ec3d9 PH |
1227 | |
1228 | DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); | |
1229 | ||
1230 | sigalrm_seen = FALSE; | |
1231 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 | 1232 | rc = SSL_accept(server_ssl); |
059ec3d9 PH |
1233 | alarm(0); |
1234 | ||
1235 | if (rc <= 0) | |
1236 | { | |
7199e1ee | 1237 | tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL); |
77bb000f PP |
1238 | if (ERR_get_error() == 0) |
1239 | log_write(0, LOG_MAIN, | |
a053d125 | 1240 | "TLS client disconnected cleanly (rejected our certificate?)"); |
059ec3d9 PH |
1241 | return FAIL; |
1242 | } | |
1243 | ||
1244 | DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); | |
1245 | ||
1246 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
1247 | and initialize things. */ | |
1248 | ||
817d9f57 JH |
1249 | construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits); |
1250 | tls_in.cipher = cipherbuf; | |
059ec3d9 PH |
1251 | |
1252 | DEBUG(D_tls) | |
1253 | { | |
1254 | uschar buf[2048]; | |
817d9f57 | 1255 | if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL) |
059ec3d9 PH |
1256 | debug_printf("Shared ciphers: %s\n", buf); |
1257 | } | |
1258 | ||
1259 | ||
817d9f57 JH |
1260 | /* Only used by the server-side tls (tls_in), including tls_getc. |
1261 | Client-side (tls_out) reads (seem to?) go via | |
1262 | smtp_read_response()/ip_recv(). | |
1263 | Hence no need to duplicate for _in and _out. | |
1264 | */ | |
059ec3d9 PH |
1265 | ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
1266 | ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; | |
1267 | ssl_xfer_eof = ssl_xfer_error = 0; | |
1268 | ||
1269 | receive_getc = tls_getc; | |
1270 | receive_ungetc = tls_ungetc; | |
1271 | receive_feof = tls_feof; | |
1272 | receive_ferror = tls_ferror; | |
58eb016e | 1273 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 1274 | |
817d9f57 | 1275 | tls_in.active = fileno(smtp_out); |
059ec3d9 PH |
1276 | return OK; |
1277 | } | |
1278 | ||
1279 | ||
1280 | ||
1281 | ||
1282 | ||
1283 | /************************************************* | |
1284 | * Start a TLS session in a client * | |
1285 | *************************************************/ | |
1286 | ||
1287 | /* Called from the smtp transport after STARTTLS has been accepted. | |
1288 | ||
1289 | Argument: | |
1290 | fd the fd of the connection | |
1291 | host connected host (for messages) | |
83da1223 | 1292 | addr the first address |
059ec3d9 PH |
1293 | dhparam DH parameter file |
1294 | certificate certificate file | |
1295 | privatekey private key file | |
3f0945ff | 1296 | sni TLS SNI to send to remote host |
059ec3d9 PH |
1297 | verify_certs file for certificate verify |
1298 | crl file containing CRL | |
1299 | require_ciphers list of allowed ciphers | |
54c90be1 PP |
1300 | dh_min_bits minimum number of bits acceptable in server's DH prime |
1301 | (unused in OpenSSL) | |
83da1223 | 1302 | timeout startup timeout |
059ec3d9 PH |
1303 | |
1304 | Returns: OK on success | |
1305 | FAIL otherwise - note that tls_error() will not give DEFER | |
1306 | because this is not a server | |
1307 | */ | |
1308 | ||
1309 | int | |
1310 | tls_client_start(int fd, host_item *host, address_item *addr, uschar *dhparam, | |
3f0945ff PP |
1311 | uschar *certificate, uschar *privatekey, uschar *sni, |
1312 | uschar *verify_certs, uschar *crl, | |
54c90be1 | 1313 | uschar *require_ciphers, int dh_min_bits ARG_UNUSED, int timeout) |
059ec3d9 PH |
1314 | { |
1315 | static uschar txt[256]; | |
1316 | uschar *expciphers; | |
1317 | X509* server_cert; | |
1318 | int rc; | |
817d9f57 | 1319 | static uschar cipherbuf[256]; |
059ec3d9 | 1320 | |
817d9f57 | 1321 | rc = tls_init(&client_ctx, host, dhparam, certificate, privatekey, |
3f7eeb86 PP |
1322 | #ifdef EXPERIMENTAL_OCSP |
1323 | NULL, | |
1324 | #endif | |
817d9f57 | 1325 | addr, &client_static_cbinfo); |
059ec3d9 PH |
1326 | if (rc != OK) return rc; |
1327 | ||
817d9f57 | 1328 | tls_out.certificate_verified = FALSE; |
a2ff477a | 1329 | client_verify_callback_called = FALSE; |
059ec3d9 PH |
1330 | |
1331 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers)) | |
1332 | return FAIL; | |
1333 | ||
1334 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
1335 | are separated by underscores. So that I can use either form in my tests, and | |
1336 | also for general convenience, we turn underscores into hyphens here. */ | |
1337 | ||
1338 | if (expciphers != NULL) | |
1339 | { | |
1340 | uschar *s = expciphers; | |
1341 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1342 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); | |
817d9f57 | 1343 | if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers)) |
7199e1ee | 1344 | return tls_error(US"SSL_CTX_set_cipher_list", host, NULL); |
059ec3d9 PH |
1345 | } |
1346 | ||
a2ff477a | 1347 | rc = setup_certs(client_ctx, verify_certs, crl, host, FALSE, TRUE); |
059ec3d9 PH |
1348 | if (rc != OK) return rc; |
1349 | ||
817d9f57 JH |
1350 | if ((client_ssl = SSL_new(client_ctx)) == NULL) return tls_error(US"SSL_new", host, NULL); |
1351 | SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx)); | |
1352 | SSL_set_fd(client_ssl, fd); | |
1353 | SSL_set_connect_state(client_ssl); | |
059ec3d9 | 1354 | |
3f0945ff PP |
1355 | if (sni) |
1356 | { | |
817d9f57 | 1357 | if (!expand_check(sni, US"tls_sni", &tls_out.sni)) |
3f0945ff | 1358 | return FAIL; |
ec4b68e5 | 1359 | if (tls_out.sni == NULL) |
2c9a0e86 PP |
1360 | { |
1361 | DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n"); | |
1362 | } | |
ec4b68e5 | 1363 | else if (!Ustrlen(tls_out.sni)) |
817d9f57 | 1364 | tls_out.sni = NULL; |
3f0945ff PP |
1365 | else |
1366 | { | |
35731706 | 1367 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 JH |
1368 | DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni); |
1369 | SSL_set_tlsext_host_name(client_ssl, tls_out.sni); | |
35731706 PP |
1370 | #else |
1371 | DEBUG(D_tls) | |
1372 | debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n", | |
1373 | tls_sni); | |
1374 | #endif | |
3f0945ff PP |
1375 | } |
1376 | } | |
1377 | ||
059ec3d9 PH |
1378 | /* There doesn't seem to be a built-in timeout on connection. */ |
1379 | ||
1380 | DEBUG(D_tls) debug_printf("Calling SSL_connect\n"); | |
1381 | sigalrm_seen = FALSE; | |
1382 | alarm(timeout); | |
817d9f57 | 1383 | rc = SSL_connect(client_ssl); |
059ec3d9 PH |
1384 | alarm(0); |
1385 | ||
1386 | if (rc <= 0) | |
7199e1ee | 1387 | return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL); |
059ec3d9 PH |
1388 | |
1389 | DEBUG(D_tls) debug_printf("SSL_connect succeeded\n"); | |
1390 | ||
453a6645 | 1391 | /* Beware anonymous ciphers which lead to server_cert being NULL */ |
817d9f57 | 1392 | server_cert = SSL_get_peer_certificate (client_ssl); |
453a6645 PP |
1393 | if (server_cert) |
1394 | { | |
817d9f57 | 1395 | tls_out.peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert), |
453a6645 | 1396 | CS txt, sizeof(txt)); |
817d9f57 | 1397 | tls_out.peerdn = txt; |
453a6645 PP |
1398 | } |
1399 | else | |
817d9f57 | 1400 | tls_out.peerdn = NULL; |
059ec3d9 | 1401 | |
817d9f57 JH |
1402 | construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits); |
1403 | tls_out.cipher = cipherbuf; | |
059ec3d9 | 1404 | |
817d9f57 | 1405 | tls_out.active = fd; |
059ec3d9 PH |
1406 | return OK; |
1407 | } | |
1408 | ||
1409 | ||
1410 | ||
1411 | ||
1412 | ||
1413 | /************************************************* | |
1414 | * TLS version of getc * | |
1415 | *************************************************/ | |
1416 | ||
1417 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
1418 | it refills the buffer via the SSL reading function. | |
1419 | ||
1420 | Arguments: none | |
1421 | Returns: the next character or EOF | |
817d9f57 JH |
1422 | |
1423 | Only used by the server-side TLS. | |
059ec3d9 PH |
1424 | */ |
1425 | ||
1426 | int | |
1427 | tls_getc(void) | |
1428 | { | |
1429 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) | |
1430 | { | |
1431 | int error; | |
1432 | int inbytes; | |
1433 | ||
817d9f57 | 1434 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl, |
c80c5570 | 1435 | ssl_xfer_buffer, ssl_xfer_buffer_size); |
059ec3d9 PH |
1436 | |
1437 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
817d9f57 JH |
1438 | inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size); |
1439 | error = SSL_get_error(server_ssl, inbytes); | |
059ec3d9 PH |
1440 | alarm(0); |
1441 | ||
1442 | /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been | |
1443 | closed down, not that the socket itself has been closed down. Revert to | |
1444 | non-SSL handling. */ | |
1445 | ||
1446 | if (error == SSL_ERROR_ZERO_RETURN) | |
1447 | { | |
1448 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
1449 | ||
1450 | receive_getc = smtp_getc; | |
1451 | receive_ungetc = smtp_ungetc; | |
1452 | receive_feof = smtp_feof; | |
1453 | receive_ferror = smtp_ferror; | |
58eb016e | 1454 | receive_smtp_buffered = smtp_buffered; |
059ec3d9 | 1455 | |
817d9f57 JH |
1456 | SSL_free(server_ssl); |
1457 | server_ssl = NULL; | |
1458 | tls_in.active = -1; | |
1459 | tls_in.bits = 0; | |
1460 | tls_in.cipher = NULL; | |
1461 | tls_in.peerdn = NULL; | |
1462 | tls_in.sni = NULL; | |
059ec3d9 PH |
1463 | |
1464 | return smtp_getc(); | |
1465 | } | |
1466 | ||
1467 | /* Handle genuine errors */ | |
1468 | ||
ba084640 PP |
1469 | else if (error == SSL_ERROR_SSL) |
1470 | { | |
1471 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
89dd51cd | 1472 | log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); |
ba084640 PP |
1473 | ssl_xfer_error = 1; |
1474 | return EOF; | |
1475 | } | |
1476 | ||
059ec3d9 PH |
1477 | else if (error != SSL_ERROR_NONE) |
1478 | { | |
1479 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
1480 | ssl_xfer_error = 1; | |
1481 | return EOF; | |
1482 | } | |
c80c5570 | 1483 | |
80a47a2c TK |
1484 | #ifndef DISABLE_DKIM |
1485 | dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); | |
1486 | #endif | |
059ec3d9 PH |
1487 | ssl_xfer_buffer_hwm = inbytes; |
1488 | ssl_xfer_buffer_lwm = 0; | |
1489 | } | |
1490 | ||
1491 | /* Something in the buffer; return next uschar */ | |
1492 | ||
1493 | return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; | |
1494 | } | |
1495 | ||
1496 | ||
1497 | ||
1498 | /************************************************* | |
1499 | * Read bytes from TLS channel * | |
1500 | *************************************************/ | |
1501 | ||
1502 | /* | |
1503 | Arguments: | |
1504 | buff buffer of data | |
1505 | len size of buffer | |
1506 | ||
1507 | Returns: the number of bytes read | |
1508 | -1 after a failed read | |
817d9f57 JH |
1509 | |
1510 | Only used by the client-side TLS. | |
059ec3d9 PH |
1511 | */ |
1512 | ||
1513 | int | |
389ca47a | 1514 | tls_read(BOOL is_server, uschar *buff, size_t len) |
059ec3d9 | 1515 | { |
389ca47a | 1516 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 PH |
1517 | int inbytes; |
1518 | int error; | |
1519 | ||
389ca47a | 1520 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl, |
c80c5570 | 1521 | buff, (unsigned int)len); |
059ec3d9 | 1522 | |
389ca47a JH |
1523 | inbytes = SSL_read(ssl, CS buff, len); |
1524 | error = SSL_get_error(ssl, inbytes); | |
059ec3d9 PH |
1525 | |
1526 | if (error == SSL_ERROR_ZERO_RETURN) | |
1527 | { | |
1528 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
1529 | return -1; | |
1530 | } | |
1531 | else if (error != SSL_ERROR_NONE) | |
1532 | { | |
1533 | return -1; | |
1534 | } | |
1535 | ||
1536 | return inbytes; | |
1537 | } | |
1538 | ||
1539 | ||
1540 | ||
1541 | ||
1542 | ||
1543 | /************************************************* | |
1544 | * Write bytes down TLS channel * | |
1545 | *************************************************/ | |
1546 | ||
1547 | /* | |
1548 | Arguments: | |
817d9f57 | 1549 | is_server channel specifier |
059ec3d9 PH |
1550 | buff buffer of data |
1551 | len number of bytes | |
1552 | ||
1553 | Returns: the number of bytes after a successful write, | |
1554 | -1 after a failed write | |
817d9f57 JH |
1555 | |
1556 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
1557 | */ |
1558 | ||
1559 | int | |
817d9f57 | 1560 | tls_write(BOOL is_server, const uschar *buff, size_t len) |
059ec3d9 PH |
1561 | { |
1562 | int outbytes; | |
1563 | int error; | |
1564 | int left = len; | |
817d9f57 | 1565 | SSL *ssl = is_server ? server_ssl : client_ssl; |
059ec3d9 | 1566 | |
c80c5570 | 1567 | DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left); |
059ec3d9 PH |
1568 | while (left > 0) |
1569 | { | |
c80c5570 | 1570 | DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left); |
059ec3d9 PH |
1571 | outbytes = SSL_write(ssl, CS buff, left); |
1572 | error = SSL_get_error(ssl, outbytes); | |
1573 | DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error); | |
1574 | switch (error) | |
1575 | { | |
1576 | case SSL_ERROR_SSL: | |
1577 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
1578 | log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); | |
1579 | return -1; | |
1580 | ||
1581 | case SSL_ERROR_NONE: | |
1582 | left -= outbytes; | |
1583 | buff += outbytes; | |
1584 | break; | |
1585 | ||
1586 | case SSL_ERROR_ZERO_RETURN: | |
1587 | log_write(0, LOG_MAIN, "SSL channel closed on write"); | |
1588 | return -1; | |
1589 | ||
817d9f57 JH |
1590 | case SSL_ERROR_SYSCALL: |
1591 | log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", | |
1592 | sender_fullhost ? sender_fullhost : US"<unknown>", | |
1593 | strerror(errno)); | |
1594 | ||
059ec3d9 PH |
1595 | default: |
1596 | log_write(0, LOG_MAIN, "SSL_write error %d", error); | |
1597 | return -1; | |
1598 | } | |
1599 | } | |
1600 | return len; | |
1601 | } | |
1602 | ||
1603 | ||
1604 | ||
1605 | /************************************************* | |
1606 | * Close down a TLS session * | |
1607 | *************************************************/ | |
1608 | ||
1609 | /* This is also called from within a delivery subprocess forked from the | |
1610 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
1611 | would tamper with the SSL session in the parent process). | |
1612 | ||
1613 | Arguments: TRUE if SSL_shutdown is to be called | |
1614 | Returns: nothing | |
817d9f57 JH |
1615 | |
1616 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
1617 | */ |
1618 | ||
1619 | void | |
817d9f57 | 1620 | tls_close(BOOL is_server, BOOL shutdown) |
059ec3d9 | 1621 | { |
817d9f57 | 1622 | SSL **sslp = is_server ? &server_ssl : &client_ssl; |
389ca47a | 1623 | int *fdp = is_server ? &tls_in.active : &tls_out.active; |
817d9f57 JH |
1624 | |
1625 | if (*fdp < 0) return; /* TLS was not active */ | |
059ec3d9 PH |
1626 | |
1627 | if (shutdown) | |
1628 | { | |
1629 | DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n"); | |
817d9f57 | 1630 | SSL_shutdown(*sslp); |
059ec3d9 PH |
1631 | } |
1632 | ||
817d9f57 JH |
1633 | SSL_free(*sslp); |
1634 | *sslp = NULL; | |
059ec3d9 | 1635 | |
817d9f57 | 1636 | *fdp = -1; |
059ec3d9 PH |
1637 | } |
1638 | ||
36f12725 NM |
1639 | |
1640 | ||
1641 | ||
3375e053 PP |
1642 | /************************************************* |
1643 | * Let tls_require_ciphers be checked at startup * | |
1644 | *************************************************/ | |
1645 | ||
1646 | /* The tls_require_ciphers option, if set, must be something which the | |
1647 | library can parse. | |
1648 | ||
1649 | Returns: NULL on success, or error message | |
1650 | */ | |
1651 | ||
1652 | uschar * | |
1653 | tls_validate_require_cipher(void) | |
1654 | { | |
1655 | SSL_CTX *ctx; | |
1656 | uschar *s, *expciphers, *err; | |
1657 | ||
1658 | /* this duplicates from tls_init(), we need a better "init just global | |
1659 | state, for no specific purpose" singleton function of our own */ | |
1660 | ||
1661 | SSL_load_error_strings(); | |
1662 | OpenSSL_add_ssl_algorithms(); | |
1663 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
1664 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the | |
1665 | list of available digests. */ | |
1666 | EVP_add_digest(EVP_sha256()); | |
1667 | #endif | |
1668 | ||
1669 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
1670 | return NULL; | |
1671 | ||
1672 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers)) | |
1673 | return US"failed to expand tls_require_ciphers"; | |
1674 | ||
1675 | if (!(expciphers && *expciphers)) | |
1676 | return NULL; | |
1677 | ||
1678 | /* normalisation ripped from above */ | |
1679 | s = expciphers; | |
1680 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
1681 | ||
1682 | err = NULL; | |
1683 | ||
1684 | ctx = SSL_CTX_new(SSLv23_server_method()); | |
1685 | if (!ctx) | |
1686 | { | |
1687 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
1688 | return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring); | |
1689 | } | |
1690 | ||
1691 | DEBUG(D_tls) | |
1692 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
1693 | ||
1694 | if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) | |
1695 | { | |
1696 | ERR_error_string(ERR_get_error(), ssl_errstring); | |
1697 | err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers); | |
1698 | } | |
1699 | ||
1700 | SSL_CTX_free(ctx); | |
1701 | ||
1702 | return err; | |
1703 | } | |
1704 | ||
1705 | ||
1706 | ||
1707 | ||
36f12725 NM |
1708 | /************************************************* |
1709 | * Report the library versions. * | |
1710 | *************************************************/ | |
1711 | ||
1712 | /* There have historically been some issues with binary compatibility in | |
1713 | OpenSSL libraries; if Exim (like many other applications) is built against | |
1714 | one version of OpenSSL but the run-time linker picks up another version, | |
1715 | it can result in serious failures, including crashing with a SIGSEGV. So | |
1716 | report the version found by the compiler and the run-time version. | |
1717 | ||
1718 | Arguments: a FILE* to print the results to | |
1719 | Returns: nothing | |
1720 | */ | |
1721 | ||
1722 | void | |
1723 | tls_version_report(FILE *f) | |
1724 | { | |
754a0503 PP |
1725 | fprintf(f, "Library version: OpenSSL: Compile: %s\n" |
1726 | " Runtime: %s\n", | |
1727 | OPENSSL_VERSION_TEXT, | |
1728 | SSLeay_version(SSLEAY_VERSION)); | |
36f12725 NM |
1729 | } |
1730 | ||
9e3331ea TK |
1731 | |
1732 | ||
1733 | ||
1734 | /************************************************* | |
17c76198 | 1735 | * Random number generation * |
9e3331ea TK |
1736 | *************************************************/ |
1737 | ||
1738 | /* Pseudo-random number generation. The result is not expected to be | |
1739 | cryptographically strong but not so weak that someone will shoot themselves | |
1740 | in the foot using it as a nonce in input in some email header scheme or | |
1741 | whatever weirdness they'll twist this into. The result should handle fork() | |
1742 | and avoid repeating sequences. OpenSSL handles that for us. | |
1743 | ||
1744 | Arguments: | |
1745 | max range maximum | |
1746 | Returns a random number in range [0, max-1] | |
1747 | */ | |
1748 | ||
1749 | int | |
17c76198 | 1750 | vaguely_random_number(int max) |
9e3331ea TK |
1751 | { |
1752 | unsigned int r; | |
1753 | int i, needed_len; | |
1754 | uschar *p; | |
1755 | uschar smallbuf[sizeof(r)]; | |
1756 | ||
1757 | if (max <= 1) | |
1758 | return 0; | |
1759 | ||
1760 | /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ | |
1761 | if (!RAND_status()) | |
1762 | { | |
1763 | randstuff r; | |
1764 | gettimeofday(&r.tv, NULL); | |
1765 | r.p = getpid(); | |
1766 | ||
1767 | RAND_seed((uschar *)(&r), sizeof(r)); | |
1768 | } | |
1769 | /* We're after pseudo-random, not random; if we still don't have enough data | |
1770 | in the internal PRNG then our options are limited. We could sleep and hope | |
1771 | for entropy to come along (prayer technique) but if the system is so depleted | |
1772 | in the first place then something is likely to just keep taking it. Instead, | |
1773 | we'll just take whatever little bit of pseudo-random we can still manage to | |
1774 | get. */ | |
1775 | ||
1776 | needed_len = sizeof(r); | |
1777 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
1778 | asked for a number less than 10. */ | |
1779 | for (r = max, i = 0; r; ++i) | |
1780 | r >>= 1; | |
1781 | i = (i + 7) / 8; | |
1782 | if (i < needed_len) | |
1783 | needed_len = i; | |
1784 | ||
1785 | /* We do not care if crypto-strong */ | |
17c76198 PP |
1786 | i = RAND_pseudo_bytes(smallbuf, needed_len); |
1787 | if (i < 0) | |
1788 | { | |
1789 | DEBUG(D_all) | |
1790 | debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n"); | |
1791 | return vaguely_random_number_fallback(max); | |
1792 | } | |
1793 | ||
9e3331ea TK |
1794 | r = 0; |
1795 | for (p = smallbuf; needed_len; --needed_len, ++p) | |
1796 | { | |
1797 | r *= 256; | |
1798 | r += *p; | |
1799 | } | |
1800 | ||
1801 | /* We don't particularly care about weighted results; if someone wants | |
1802 | smooth distribution and cares enough then they should submit a patch then. */ | |
1803 | return r % max; | |
1804 | } | |
1805 | ||
77bb000f PP |
1806 | |
1807 | ||
1808 | ||
1809 | /************************************************* | |
1810 | * OpenSSL option parse * | |
1811 | *************************************************/ | |
1812 | ||
1813 | /* Parse one option for tls_openssl_options_parse below | |
1814 | ||
1815 | Arguments: | |
1816 | name one option name | |
1817 | value place to store a value for it | |
1818 | Returns success or failure in parsing | |
1819 | */ | |
1820 | ||
1821 | struct exim_openssl_option { | |
1822 | uschar *name; | |
1823 | long value; | |
1824 | }; | |
1825 | /* We could use a macro to expand, but we need the ifdef and not all the | |
1826 | options document which version they were introduced in. Policylet: include | |
1827 | all options unless explicitly for DTLS, let the administrator choose which | |
1828 | to apply. | |
1829 | ||
1830 | This list is current as of: | |
c80c5570 | 1831 | ==> 1.0.1b <== */ |
77bb000f PP |
1832 | static struct exim_openssl_option exim_openssl_options[] = { |
1833 | /* KEEP SORTED ALPHABETICALLY! */ | |
1834 | #ifdef SSL_OP_ALL | |
73a46702 | 1835 | { US"all", SSL_OP_ALL }, |
77bb000f PP |
1836 | #endif |
1837 | #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION | |
73a46702 | 1838 | { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, |
77bb000f PP |
1839 | #endif |
1840 | #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE | |
73a46702 | 1841 | { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, |
77bb000f PP |
1842 | #endif |
1843 | #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS | |
73a46702 | 1844 | { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, |
77bb000f PP |
1845 | #endif |
1846 | #ifdef SSL_OP_EPHEMERAL_RSA | |
73a46702 | 1847 | { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, |
77bb000f PP |
1848 | #endif |
1849 | #ifdef SSL_OP_LEGACY_SERVER_CONNECT | |
73a46702 | 1850 | { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, |
77bb000f PP |
1851 | #endif |
1852 | #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER | |
73a46702 | 1853 | { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, |
77bb000f PP |
1854 | #endif |
1855 | #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG | |
73a46702 | 1856 | { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, |
77bb000f PP |
1857 | #endif |
1858 | #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING | |
73a46702 | 1859 | { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, |
77bb000f PP |
1860 | #endif |
1861 | #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG | |
73a46702 | 1862 | { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, |
77bb000f PP |
1863 | #endif |
1864 | #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG | |
73a46702 | 1865 | { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, |
77bb000f | 1866 | #endif |
c80c5570 PP |
1867 | #ifdef SSL_OP_NO_COMPRESSION |
1868 | { US"no_compression", SSL_OP_NO_COMPRESSION }, | |
1869 | #endif | |
77bb000f | 1870 | #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |
73a46702 | 1871 | { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, |
77bb000f | 1872 | #endif |
c0c7b2da PP |
1873 | #ifdef SSL_OP_NO_SSLv2 |
1874 | { US"no_sslv2", SSL_OP_NO_SSLv2 }, | |
1875 | #endif | |
1876 | #ifdef SSL_OP_NO_SSLv3 | |
1877 | { US"no_sslv3", SSL_OP_NO_SSLv3 }, | |
1878 | #endif | |
1879 | #ifdef SSL_OP_NO_TICKET | |
1880 | { US"no_ticket", SSL_OP_NO_TICKET }, | |
1881 | #endif | |
1882 | #ifdef SSL_OP_NO_TLSv1 | |
1883 | { US"no_tlsv1", SSL_OP_NO_TLSv1 }, | |
1884 | #endif | |
c80c5570 PP |
1885 | #ifdef SSL_OP_NO_TLSv1_1 |
1886 | #if SSL_OP_NO_TLSv1_1 == 0x00000400L | |
1887 | /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */ | |
1888 | #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring | |
1889 | #else | |
1890 | { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 }, | |
1891 | #endif | |
1892 | #endif | |
1893 | #ifdef SSL_OP_NO_TLSv1_2 | |
1894 | { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 }, | |
1895 | #endif | |
77bb000f | 1896 | #ifdef SSL_OP_SINGLE_DH_USE |
73a46702 | 1897 | { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, |
77bb000f PP |
1898 | #endif |
1899 | #ifdef SSL_OP_SINGLE_ECDH_USE | |
73a46702 | 1900 | { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, |
77bb000f PP |
1901 | #endif |
1902 | #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG | |
73a46702 | 1903 | { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, |
77bb000f PP |
1904 | #endif |
1905 | #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG | |
73a46702 | 1906 | { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, |
77bb000f PP |
1907 | #endif |
1908 | #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG | |
73a46702 | 1909 | { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, |
77bb000f PP |
1910 | #endif |
1911 | #ifdef SSL_OP_TLS_D5_BUG | |
73a46702 | 1912 | { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, |
77bb000f PP |
1913 | #endif |
1914 | #ifdef SSL_OP_TLS_ROLLBACK_BUG | |
73a46702 | 1915 | { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, |
77bb000f PP |
1916 | #endif |
1917 | }; | |
1918 | static int exim_openssl_options_size = | |
1919 | sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option); | |
1920 | ||
c80c5570 | 1921 | |
77bb000f PP |
1922 | static BOOL |
1923 | tls_openssl_one_option_parse(uschar *name, long *value) | |
1924 | { | |
1925 | int first = 0; | |
1926 | int last = exim_openssl_options_size; | |
1927 | while (last > first) | |
1928 | { | |
1929 | int middle = (first + last)/2; | |
1930 | int c = Ustrcmp(name, exim_openssl_options[middle].name); | |
1931 | if (c == 0) | |
1932 | { | |
1933 | *value = exim_openssl_options[middle].value; | |
1934 | return TRUE; | |
1935 | } | |
1936 | else if (c > 0) | |
1937 | first = middle + 1; | |
1938 | else | |
1939 | last = middle; | |
1940 | } | |
1941 | return FALSE; | |
1942 | } | |
1943 | ||
1944 | ||
1945 | ||
1946 | ||
1947 | /************************************************* | |
1948 | * OpenSSL option parsing logic * | |
1949 | *************************************************/ | |
1950 | ||
1951 | /* OpenSSL has a number of compatibility options which an administrator might | |
1952 | reasonably wish to set. Interpret a list similarly to decode_bits(), so that | |
1953 | we look like log_selector. | |
1954 | ||
1955 | Arguments: | |
1956 | option_spec the administrator-supplied string of options | |
1957 | results ptr to long storage for the options bitmap | |
1958 | Returns success or failure | |
1959 | */ | |
1960 | ||
1961 | BOOL | |
1962 | tls_openssl_options_parse(uschar *option_spec, long *results) | |
1963 | { | |
1964 | long result, item; | |
1965 | uschar *s, *end; | |
1966 | uschar keep_c; | |
1967 | BOOL adding, item_parsed; | |
1968 | ||
0e944a0d | 1969 | result = 0L; |
b1770b6e | 1970 | /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed |
da3ad30d | 1971 | * from default because it increases BEAST susceptibility. */ |
f0f5a555 PP |
1972 | #ifdef SSL_OP_NO_SSLv2 |
1973 | result |= SSL_OP_NO_SSLv2; | |
1974 | #endif | |
77bb000f PP |
1975 | |
1976 | if (option_spec == NULL) | |
1977 | { | |
1978 | *results = result; | |
1979 | return TRUE; | |
1980 | } | |
1981 | ||
1982 | for (s=option_spec; *s != '\0'; /**/) | |
1983 | { | |
1984 | while (isspace(*s)) ++s; | |
1985 | if (*s == '\0') | |
1986 | break; | |
1987 | if (*s != '+' && *s != '-') | |
1988 | { | |
1989 | DEBUG(D_tls) debug_printf("malformed openssl option setting: " | |
0e944a0d | 1990 | "+ or - expected but found \"%s\"\n", s); |
77bb000f PP |
1991 | return FALSE; |
1992 | } | |
1993 | adding = *s++ == '+'; | |
1994 | for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; | |
1995 | keep_c = *end; | |
1996 | *end = '\0'; | |
1997 | item_parsed = tls_openssl_one_option_parse(s, &item); | |
1998 | if (!item_parsed) | |
1999 | { | |
0e944a0d | 2000 | DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); |
77bb000f PP |
2001 | return FALSE; |
2002 | } | |
2003 | DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n", | |
2004 | adding ? "adding" : "removing", result, item, s); | |
2005 | if (adding) | |
2006 | result |= item; | |
2007 | else | |
2008 | result &= ~item; | |
2009 | *end = keep_c; | |
2010 | s = end; | |
2011 | } | |
2012 | ||
2013 | *results = result; | |
2014 | return TRUE; | |
2015 | } | |
2016 | ||
059ec3d9 | 2017 | /* End of tls-openssl.c */ |