Commit | Line | Data |
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059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
b10c87b3 | 5 | /* Copyright (c) University of Cambridge 1995 - 2019 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
f5d78688 JH |
8 | /* Portions Copyright (c) The OpenSSL Project 1999 */ |
9 | ||
059ec3d9 PH |
10 | /* This module provides the TLS (aka SSL) support for Exim using the OpenSSL |
11 | library. It is #included into the tls.c file when that library is used. The | |
12 | code herein is based on a patch that was originally contributed by Steve | |
13 | Haslam. It was adapted from stunnel, a GPL program by Michal Trojnara. | |
14 | ||
15 | No cryptographic code is included in Exim. All this module does is to call | |
16 | functions from the OpenSSL library. */ | |
17 | ||
18 | ||
19 | /* Heading stuff */ | |
20 | ||
21 | #include <openssl/lhash.h> | |
22 | #include <openssl/ssl.h> | |
23 | #include <openssl/err.h> | |
24 | #include <openssl/rand.h> | |
10ca4f1c JH |
25 | #ifndef OPENSSL_NO_ECDH |
26 | # include <openssl/ec.h> | |
27 | #endif | |
f2de3a33 | 28 | #ifndef DISABLE_OCSP |
e51c7be2 | 29 | # include <openssl/ocsp.h> |
3f7eeb86 | 30 | #endif |
c0635b6d | 31 | #ifdef SUPPORT_DANE |
05e796ad | 32 | # include "danessl.h" |
85098ee7 JH |
33 | #endif |
34 | ||
3f7eeb86 | 35 | |
f2de3a33 JH |
36 | #ifndef DISABLE_OCSP |
37 | # define EXIM_OCSP_SKEW_SECONDS (300L) | |
38 | # define EXIM_OCSP_MAX_AGE (-1L) | |
3f7eeb86 | 39 | #endif |
059ec3d9 | 40 | |
3bcbbbe2 | 41 | #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT) |
e51c7be2 | 42 | # define EXIM_HAVE_OPENSSL_TLSEXT |
3bcbbbe2 | 43 | #endif |
c8dfb21d JH |
44 | #if OPENSSL_VERSION_NUMBER >= 0x00908000L |
45 | # define EXIM_HAVE_RSA_GENKEY_EX | |
46 | #endif | |
47 | #if OPENSSL_VERSION_NUMBER >= 0x10100000L | |
48 | # define EXIM_HAVE_OCSP_RESP_COUNT | |
b038d456 | 49 | # define OPENSSL_AUTO_SHA256 |
c8dfb21d JH |
50 | #else |
51 | # define EXIM_HAVE_EPHEM_RSA_KEX | |
52 | # define EXIM_HAVE_RAND_PSEUDO | |
53 | #endif | |
54 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
8442641e | 55 | # define EXIM_HAVE_SHA256 |
c8dfb21d | 56 | #endif |
34e3241d | 57 | |
d7978c0f JH |
58 | /* X509_check_host provides sane certificate hostname checking, but was added |
59 | to OpenSSL late, after other projects forked off the code-base. So in | |
60 | addition to guarding against the base version number, beware that LibreSSL | |
61 | does not (at this time) support this function. | |
62 | ||
63 | If LibreSSL gains a different API, perhaps via libtls, then we'll probably | |
64 | opt to disentangle and ask a LibreSSL user to provide glue for a third | |
65 | crypto provider for libtls instead of continuing to tie the OpenSSL glue | |
66 | into even twistier knots. If LibreSSL gains the same API, we can just | |
67 | change this guard and punt the issue for a while longer. */ | |
68 | ||
34e3241d PP |
69 | #ifndef LIBRESSL_VERSION_NUMBER |
70 | # if OPENSSL_VERSION_NUMBER >= 0x010100000L | |
71 | # define EXIM_HAVE_OPENSSL_CHECKHOST | |
8420742d | 72 | # define EXIM_HAVE_OPENSSL_DH_BITS |
7a8b9519 | 73 | # define EXIM_HAVE_OPENSSL_TLS_METHOD |
f20cfa4a | 74 | # define EXIM_HAVE_OPENSSL_KEYLOG |
f1be21cf | 75 | # define EXIM_HAVE_OPENSSL_CIPHER_GET_ID |
b10c87b3 | 76 | # define EXIM_HAVE_SESSION_TICKET |
e570d136 | 77 | # define EXIM_HAVE_OPESSL_TRACE |
012dd02e | 78 | # define EXIM_HAVE_OPESSL_GET0_SERIAL |
97277c1f JH |
79 | # ifndef DISABLE_OCSP |
80 | # define EXIM_HAVE_OCSP | |
81 | # endif | |
7434882d JH |
82 | # else |
83 | # define EXIM_NEED_OPENSSL_INIT | |
34e3241d PP |
84 | # endif |
85 | # if OPENSSL_VERSION_NUMBER >= 0x010000000L \ | |
2dfb468b | 86 | && (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L |
34e3241d PP |
87 | # define EXIM_HAVE_OPENSSL_CHECKHOST |
88 | # endif | |
11aa88b0 | 89 | #endif |
10ca4f1c | 90 | |
11aa88b0 RA |
91 | #if !defined(LIBRESSL_VERSION_NUMBER) \ |
92 | || LIBRESSL_VERSION_NUMBER >= 0x20010000L | |
10ca4f1c JH |
93 | # if !defined(OPENSSL_NO_ECDH) |
94 | # if OPENSSL_VERSION_NUMBER >= 0x0090800fL | |
8442641e | 95 | # define EXIM_HAVE_ECDH |
10ca4f1c JH |
96 | # endif |
97 | # if OPENSSL_VERSION_NUMBER >= 0x10002000L | |
10ca4f1c JH |
98 | # define EXIM_HAVE_OPENSSL_EC_NIST2NID |
99 | # endif | |
100 | # endif | |
2dfb468b | 101 | #endif |
3bcbbbe2 | 102 | |
8a40db1c JH |
103 | #ifndef LIBRESSL_VERSION_NUMBER |
104 | # if OPENSSL_VERSION_NUMBER >= 0x010101000L | |
105 | # define OPENSSL_HAVE_KEYLOG_CB | |
d7f31bb6 | 106 | # define OPENSSL_HAVE_NUM_TICKETS |
f1be21cf | 107 | # define EXIM_HAVE_OPENSSL_CIPHER_STD_NAME |
97277c1f JH |
108 | # else |
109 | # define OPENSSL_BAD_SRVR_OURCERT | |
8a40db1c JH |
110 | # endif |
111 | #endif | |
112 | ||
67791ce4 JH |
113 | #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP) |
114 | # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile" | |
115 | # define DISABLE_OCSP | |
116 | #endif | |
43e2db44 JH |
117 | |
118 | #ifdef EXPERIMENTAL_TLS_RESUME | |
119 | # if OPENSSL_VERSION_NUMBER < 0x0101010L | |
120 | # error OpenSSL version too old for session-resumption | |
121 | # endif | |
122 | #endif | |
67791ce4 | 123 | |
a6510420 JH |
124 | #ifdef EXIM_HAVE_OPENSSL_CHECKHOST |
125 | # include <openssl/x509v3.h> | |
126 | #endif | |
127 | ||
f1be21cf JH |
128 | #ifndef EXIM_HAVE_OPENSSL_CIPHER_STD_NAME |
129 | # ifndef EXIM_HAVE_OPENSSL_CIPHER_GET_ID | |
130 | # define SSL_CIPHER_get_id(c) (c->id) | |
131 | # endif | |
dca6d121 JH |
132 | # ifndef MACRO_PREDEF |
133 | # include "tls-cipher-stdname.c" | |
134 | # endif | |
f1be21cf JH |
135 | #endif |
136 | ||
8442641e JH |
137 | /************************************************* |
138 | * OpenSSL option parse * | |
139 | *************************************************/ | |
140 | ||
141 | typedef struct exim_openssl_option { | |
142 | uschar *name; | |
143 | long value; | |
144 | } exim_openssl_option; | |
145 | /* We could use a macro to expand, but we need the ifdef and not all the | |
146 | options document which version they were introduced in. Policylet: include | |
147 | all options unless explicitly for DTLS, let the administrator choose which | |
148 | to apply. | |
149 | ||
150 | This list is current as of: | |
151 | ==> 1.0.1b <== | |
152 | Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev | |
153 | Plus SSL_OP_NO_TLSv1_3 for 1.1.2-dev | |
154 | */ | |
155 | static exim_openssl_option exim_openssl_options[] = { | |
156 | /* KEEP SORTED ALPHABETICALLY! */ | |
157 | #ifdef SSL_OP_ALL | |
6d95688d | 158 | { US"all", (long) SSL_OP_ALL }, |
8442641e JH |
159 | #endif |
160 | #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION | |
161 | { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, | |
162 | #endif | |
163 | #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE | |
164 | { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, | |
165 | #endif | |
166 | #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS | |
167 | { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, | |
168 | #endif | |
169 | #ifdef SSL_OP_EPHEMERAL_RSA | |
170 | { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, | |
171 | #endif | |
172 | #ifdef SSL_OP_LEGACY_SERVER_CONNECT | |
173 | { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, | |
174 | #endif | |
175 | #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER | |
176 | { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, | |
177 | #endif | |
178 | #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG | |
179 | { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, | |
180 | #endif | |
181 | #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING | |
182 | { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, | |
183 | #endif | |
184 | #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG | |
185 | { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, | |
186 | #endif | |
187 | #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG | |
188 | { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, | |
189 | #endif | |
190 | #ifdef SSL_OP_NO_COMPRESSION | |
191 | { US"no_compression", SSL_OP_NO_COMPRESSION }, | |
192 | #endif | |
193 | #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION | |
194 | { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, | |
195 | #endif | |
196 | #ifdef SSL_OP_NO_SSLv2 | |
197 | { US"no_sslv2", SSL_OP_NO_SSLv2 }, | |
198 | #endif | |
199 | #ifdef SSL_OP_NO_SSLv3 | |
200 | { US"no_sslv3", SSL_OP_NO_SSLv3 }, | |
201 | #endif | |
202 | #ifdef SSL_OP_NO_TICKET | |
203 | { US"no_ticket", SSL_OP_NO_TICKET }, | |
204 | #endif | |
205 | #ifdef SSL_OP_NO_TLSv1 | |
206 | { US"no_tlsv1", SSL_OP_NO_TLSv1 }, | |
207 | #endif | |
208 | #ifdef SSL_OP_NO_TLSv1_1 | |
209 | #if SSL_OP_NO_TLSv1_1 == 0x00000400L | |
210 | /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */ | |
211 | #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring | |
212 | #else | |
213 | { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 }, | |
214 | #endif | |
215 | #endif | |
216 | #ifdef SSL_OP_NO_TLSv1_2 | |
217 | { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 }, | |
218 | #endif | |
219 | #ifdef SSL_OP_NO_TLSv1_3 | |
220 | { US"no_tlsv1_3", SSL_OP_NO_TLSv1_3 }, | |
221 | #endif | |
222 | #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG | |
223 | { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG }, | |
224 | #endif | |
225 | #ifdef SSL_OP_SINGLE_DH_USE | |
226 | { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, | |
227 | #endif | |
228 | #ifdef SSL_OP_SINGLE_ECDH_USE | |
229 | { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, | |
230 | #endif | |
231 | #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG | |
232 | { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, | |
233 | #endif | |
234 | #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG | |
235 | { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, | |
236 | #endif | |
237 | #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG | |
238 | { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, | |
239 | #endif | |
240 | #ifdef SSL_OP_TLS_D5_BUG | |
241 | { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, | |
242 | #endif | |
243 | #ifdef SSL_OP_TLS_ROLLBACK_BUG | |
244 | { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, | |
245 | #endif | |
246 | }; | |
247 | ||
248 | #ifndef MACRO_PREDEF | |
249 | static int exim_openssl_options_size = nelem(exim_openssl_options); | |
250 | #endif | |
251 | ||
252 | #ifdef MACRO_PREDEF | |
253 | void | |
254 | options_tls(void) | |
255 | { | |
8442641e JH |
256 | uschar buf[64]; |
257 | ||
d7978c0f | 258 | for (struct exim_openssl_option * o = exim_openssl_options; |
8442641e JH |
259 | o < exim_openssl_options + nelem(exim_openssl_options); o++) |
260 | { | |
261 | /* Trailing X is workaround for problem with _OPT_OPENSSL_NO_TLSV1 | |
262 | being a ".ifdef _OPT_OPENSSL_NO_TLSV1_3" match */ | |
263 | ||
264 | spf(buf, sizeof(buf), US"_OPT_OPENSSL_%T_X", o->name); | |
265 | builtin_macro_create(buf); | |
266 | } | |
b10c87b3 JH |
267 | |
268 | # ifdef EXPERIMENTAL_TLS_RESUME | |
269 | builtin_macro_create_var(US"_RESUME_DECODE", RESUME_DECODE_STRING ); | |
270 | # endif | |
e326959e JH |
271 | # ifdef SSL_OP_NO_TLSv1_3 |
272 | builtin_macro_create(US"_HAVE_TLS1_3"); | |
273 | # endif | |
97277c1f JH |
274 | # ifdef OPENSSL_BAD_SRVR_OURCERT |
275 | builtin_macro_create(US"_TLS_BAD_MULTICERT_IN_OURCERT"); | |
276 | # endif | |
277 | # ifdef EXIM_HAVE_OCSP | |
278 | builtin_macro_create(US"_HAVE_TLS_OCSP"); | |
279 | builtin_macro_create(US"_HAVE_TLS_OCSP_LIST"); | |
280 | # endif | |
8442641e JH |
281 | } |
282 | #else | |
283 | ||
284 | /******************************************************************************/ | |
285 | ||
059ec3d9 PH |
286 | /* Structure for collecting random data for seeding. */ |
287 | ||
288 | typedef struct randstuff { | |
9e3331ea TK |
289 | struct timeval tv; |
290 | pid_t p; | |
059ec3d9 PH |
291 | } randstuff; |
292 | ||
293 | /* Local static variables */ | |
294 | ||
a2ff477a JH |
295 | static BOOL client_verify_callback_called = FALSE; |
296 | static BOOL server_verify_callback_called = FALSE; | |
059ec3d9 PH |
297 | static const uschar *sid_ctx = US"exim"; |
298 | ||
d4f09789 PP |
299 | /* We have three different contexts to care about. |
300 | ||
301 | Simple case: client, `client_ctx` | |
302 | As a client, we can be doing a callout or cut-through delivery while receiving | |
303 | a message. So we have a client context, which should have options initialised | |
74f1a423 JH |
304 | from the SMTP Transport. We may also concurrently want to make TLS connections |
305 | to utility daemons, so client-contexts are allocated and passed around in call | |
306 | args rather than using a gobal. | |
d4f09789 PP |
307 | |
308 | Server: | |
309 | There are two cases: with and without ServerNameIndication from the client. | |
310 | Given TLS SNI, we can be using different keys, certs and various other | |
311 | configuration settings, because they're re-expanded with $tls_sni set. This | |
312 | allows vhosting with TLS. This SNI is sent in the handshake. | |
313 | A client might not send SNI, so we need a fallback, and an initial setup too. | |
314 | So as a server, we start out using `server_ctx`. | |
315 | If SNI is sent by the client, then we as server, mid-negotiation, try to clone | |
316 | `server_sni` from `server_ctx` and then initialise settings by re-expanding | |
317 | configuration. | |
318 | */ | |
319 | ||
74f1a423 JH |
320 | typedef struct { |
321 | SSL_CTX * ctx; | |
322 | SSL * ssl; | |
c09dbcfb | 323 | gstring * corked; |
74f1a423 JH |
324 | } exim_openssl_client_tls_ctx; |
325 | ||
817d9f57 | 326 | static SSL_CTX *server_ctx = NULL; |
817d9f57 | 327 | static SSL *server_ssl = NULL; |
389ca47a | 328 | |
35731706 | 329 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 | 330 | static SSL_CTX *server_sni = NULL; |
35731706 | 331 | #endif |
059ec3d9 PH |
332 | |
333 | static char ssl_errstring[256]; | |
334 | ||
dea4b568 | 335 | static int ssl_session_timeout = 7200; /* Two hours */ |
a2ff477a JH |
336 | static BOOL client_verify_optional = FALSE; |
337 | static BOOL server_verify_optional = FALSE; | |
059ec3d9 | 338 | |
f5d78688 | 339 | static BOOL reexpand_tls_files_for_sni = FALSE; |
059ec3d9 PH |
340 | |
341 | ||
5b2fd993 JH |
342 | typedef struct ocsp_resp { |
343 | struct ocsp_resp * next; | |
344 | OCSP_RESPONSE * resp; | |
345 | } ocsp_resplist; | |
346 | ||
7be682ca | 347 | typedef struct tls_ext_ctx_cb { |
b10c87b3 | 348 | tls_support * tlsp; |
7be682ca PP |
349 | uschar *certificate; |
350 | uschar *privatekey; | |
f5d78688 | 351 | BOOL is_server; |
a6510420 | 352 | #ifndef DISABLE_OCSP |
c3033f13 | 353 | STACK_OF(X509) *verify_stack; /* chain for verifying the proof */ |
f5d78688 JH |
354 | union { |
355 | struct { | |
356 | uschar *file; | |
5b2fd993 JH |
357 | const uschar *file_expanded; |
358 | ocsp_resplist *olist; | |
f5d78688 JH |
359 | } server; |
360 | struct { | |
44662487 JH |
361 | X509_STORE *verify_store; /* non-null if status requested */ |
362 | BOOL verify_required; | |
f5d78688 JH |
363 | } client; |
364 | } u_ocsp; | |
3f7eeb86 | 365 | #endif |
7be682ca PP |
366 | uschar *dhparam; |
367 | /* these are cached from first expand */ | |
368 | uschar *server_cipher_list; | |
369 | /* only passed down to tls_error: */ | |
370 | host_item *host; | |
55414b25 | 371 | const uschar * verify_cert_hostnames; |
0cbf2b82 | 372 | #ifndef DISABLE_EVENT |
a7538db1 JH |
373 | uschar * event_action; |
374 | #endif | |
7be682ca PP |
375 | } tls_ext_ctx_cb; |
376 | ||
377 | /* should figure out a cleanup of API to handle state preserved per | |
378 | implementation, for various reasons, which can be void * in the APIs. | |
379 | For now, we hack around it. */ | |
b10c87b3 | 380 | tls_ext_ctx_cb *client_static_cbinfo = NULL; /*XXX should not use static; multiple concurrent clients! */ |
817d9f57 | 381 | tls_ext_ctx_cb *server_static_cbinfo = NULL; |
7be682ca PP |
382 | |
383 | static int | |
983207c1 | 384 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
cf0c6164 | 385 | int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr ); |
059ec3d9 | 386 | |
3f7eeb86 | 387 | /* Callbacks */ |
3bcbbbe2 | 388 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
3f7eeb86 | 389 | static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg); |
3bcbbbe2 | 390 | #endif |
f2de3a33 | 391 | #ifndef DISABLE_OCSP |
f5d78688 | 392 | static int tls_server_stapling_cb(SSL *s, void *arg); |
3f7eeb86 PP |
393 | #endif |
394 | ||
059ec3d9 | 395 | |
b10c87b3 | 396 | |
4d93129f | 397 | /* Daemon-called, before every connection, key create/rotate */ |
b10c87b3 JH |
398 | #ifdef EXPERIMENTAL_TLS_RESUME |
399 | static void tk_init(void); | |
400 | static int tls_exdata_idx = -1; | |
401 | #endif | |
402 | ||
403 | void | |
404 | tls_daemon_init(void) | |
405 | { | |
406 | #ifdef EXPERIMENTAL_TLS_RESUME | |
407 | tk_init(); | |
408 | #endif | |
409 | return; | |
410 | } | |
411 | ||
412 | ||
059ec3d9 PH |
413 | /************************************************* |
414 | * Handle TLS error * | |
415 | *************************************************/ | |
416 | ||
417 | /* Called from lots of places when errors occur before actually starting to do | |
418 | the TLS handshake, that is, while the session is still in clear. Always returns | |
419 | DEFER for a server and FAIL for a client so that most calls can use "return | |
420 | tls_error(...)" to do this processing and then give an appropriate return. A | |
421 | single function is used for both server and client, because it is called from | |
422 | some shared functions. | |
423 | ||
424 | Argument: | |
425 | prefix text to include in the logged error | |
426 | host NULL if setting up a server; | |
427 | the connected host if setting up a client | |
7199e1ee | 428 | msg error message or NULL if we should ask OpenSSL |
cf0c6164 | 429 | errstr pointer to output error message |
059ec3d9 PH |
430 | |
431 | Returns: OK/DEFER/FAIL | |
432 | */ | |
433 | ||
434 | static int | |
cf0c6164 | 435 | tls_error(uschar * prefix, const host_item * host, uschar * msg, uschar ** errstr) |
059ec3d9 | 436 | { |
c562fd30 | 437 | if (!msg) |
7199e1ee | 438 | { |
0abc5a13 | 439 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
cf0c6164 | 440 | msg = US ssl_errstring; |
7199e1ee TF |
441 | } |
442 | ||
5a2a0989 JH |
443 | msg = string_sprintf("(%s): %s", prefix, msg); |
444 | DEBUG(D_tls) debug_printf("TLS error '%s'\n", msg); | |
445 | if (errstr) *errstr = msg; | |
cf0c6164 | 446 | return host ? FAIL : DEFER; |
059ec3d9 PH |
447 | } |
448 | ||
449 | ||
450 | ||
451 | /************************************************* | |
452 | * Callback to generate RSA key * | |
453 | *************************************************/ | |
454 | ||
455 | /* | |
456 | Arguments: | |
3ae79556 | 457 | s SSL connection (not used) |
059ec3d9 PH |
458 | export not used |
459 | keylength keylength | |
460 | ||
461 | Returns: pointer to generated key | |
462 | */ | |
463 | ||
464 | static RSA * | |
465 | rsa_callback(SSL *s, int export, int keylength) | |
466 | { | |
467 | RSA *rsa_key; | |
c8dfb21d JH |
468 | #ifdef EXIM_HAVE_RSA_GENKEY_EX |
469 | BIGNUM *bn = BN_new(); | |
470 | #endif | |
471 | ||
059ec3d9 PH |
472 | export = export; /* Shut picky compilers up */ |
473 | DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength); | |
c8dfb21d JH |
474 | |
475 | #ifdef EXIM_HAVE_RSA_GENKEY_EX | |
476 | if ( !BN_set_word(bn, (unsigned long)RSA_F4) | |
f2cb6292 | 477 | || !(rsa_key = RSA_new()) |
c8dfb21d JH |
478 | || !RSA_generate_key_ex(rsa_key, keylength, bn, NULL) |
479 | ) | |
480 | #else | |
23bb6982 | 481 | if (!(rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL))) |
c8dfb21d JH |
482 | #endif |
483 | ||
059ec3d9 | 484 | { |
0abc5a13 | 485 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
059ec3d9 PH |
486 | log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s", |
487 | ssl_errstring); | |
488 | return NULL; | |
489 | } | |
490 | return rsa_key; | |
491 | } | |
492 | ||
493 | ||
494 | ||
f5d78688 | 495 | /* Extreme debug |
f2de3a33 | 496 | #ifndef DISABLE_OCSP |
f5d78688 JH |
497 | void |
498 | x509_store_dump_cert_s_names(X509_STORE * store) | |
499 | { | |
500 | STACK_OF(X509_OBJECT) * roots= store->objs; | |
f5d78688 JH |
501 | static uschar name[256]; |
502 | ||
d7978c0f | 503 | for (int i= 0; i < sk_X509_OBJECT_num(roots); i++) |
f5d78688 JH |
504 | { |
505 | X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i); | |
506 | if(tmp_obj->type == X509_LU_X509) | |
507 | { | |
70e384dd JH |
508 | X509_NAME * sn = X509_get_subject_name(tmp_obj->data.x509); |
509 | if (X509_NAME_oneline(sn, CS name, sizeof(name))) | |
510 | { | |
511 | name[sizeof(name)-1] = '\0'; | |
512 | debug_printf(" %s\n", name); | |
513 | } | |
f5d78688 JH |
514 | } |
515 | } | |
516 | } | |
517 | #endif | |
518 | */ | |
519 | ||
059ec3d9 | 520 | |
0cbf2b82 | 521 | #ifndef DISABLE_EVENT |
f69979cf JH |
522 | static int |
523 | verify_event(tls_support * tlsp, X509 * cert, int depth, const uschar * dn, | |
524 | BOOL *calledp, const BOOL *optionalp, const uschar * what) | |
525 | { | |
526 | uschar * ev; | |
527 | uschar * yield; | |
528 | X509 * old_cert; | |
529 | ||
530 | ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action; | |
531 | if (ev) | |
532 | { | |
aaba7d03 | 533 | DEBUG(D_tls) debug_printf("verify_event: %s %d\n", what, depth); |
f69979cf JH |
534 | old_cert = tlsp->peercert; |
535 | tlsp->peercert = X509_dup(cert); | |
536 | /* NB we do not bother setting peerdn */ | |
537 | if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth)))) | |
538 | { | |
539 | log_write(0, LOG_MAIN, "[%s] %s verify denied by event-action: " | |
540 | "depth=%d cert=%s: %s", | |
541 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
542 | what, depth, dn, yield); | |
543 | *calledp = TRUE; | |
544 | if (!*optionalp) | |
545 | { | |
546 | if (old_cert) tlsp->peercert = old_cert; /* restore 1st failing cert */ | |
547 | return 1; /* reject (leaving peercert set) */ | |
548 | } | |
549 | DEBUG(D_tls) debug_printf("Event-action verify failure overridden " | |
550 | "(host in tls_try_verify_hosts)\n"); | |
4a1bd6b9 | 551 | tlsp->verify_override = TRUE; |
f69979cf JH |
552 | } |
553 | X509_free(tlsp->peercert); | |
554 | tlsp->peercert = old_cert; | |
555 | } | |
556 | return 0; | |
557 | } | |
558 | #endif | |
559 | ||
059ec3d9 PH |
560 | /************************************************* |
561 | * Callback for verification * | |
562 | *************************************************/ | |
563 | ||
564 | /* The SSL library does certificate verification if set up to do so. This | |
565 | callback has the current yes/no state is in "state". If verification succeeded, | |
f69979cf JH |
566 | we set the certificate-verified flag. If verification failed, what happens |
567 | depends on whether the client is required to present a verifiable certificate | |
568 | or not. | |
059ec3d9 PH |
569 | |
570 | If verification is optional, we change the state to yes, but still log the | |
571 | verification error. For some reason (it really would help to have proper | |
572 | documentation of OpenSSL), this callback function then gets called again, this | |
f69979cf JH |
573 | time with state = 1. We must take care not to set the private verified flag on |
574 | the second time through. | |
059ec3d9 PH |
575 | |
576 | Note: this function is not called if the client fails to present a certificate | |
577 | when asked. We get here only if a certificate has been received. Handling of | |
578 | optional verification for this case is done when requesting SSL to verify, by | |
579 | setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case. | |
580 | ||
a7538db1 JH |
581 | May be called multiple times for different issues with a certificate, even |
582 | for a given "depth" in the certificate chain. | |
583 | ||
059ec3d9 | 584 | Arguments: |
f2f2c91b JH |
585 | preverify_ok current yes/no state as 1/0 |
586 | x509ctx certificate information. | |
587 | tlsp per-direction (client vs. server) support data | |
588 | calledp has-been-called flag | |
589 | optionalp verification-is-optional flag | |
059ec3d9 | 590 | |
f2f2c91b | 591 | Returns: 0 if verification should fail, otherwise 1 |
059ec3d9 PH |
592 | */ |
593 | ||
594 | static int | |
70e384dd JH |
595 | verify_callback(int preverify_ok, X509_STORE_CTX * x509ctx, |
596 | tls_support * tlsp, BOOL * calledp, BOOL * optionalp) | |
059ec3d9 | 597 | { |
421aff85 | 598 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); |
a7538db1 | 599 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
f69979cf | 600 | uschar dn[256]; |
059ec3d9 | 601 | |
70e384dd JH |
602 | if (!X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn))) |
603 | { | |
604 | DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); | |
605 | log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", | |
606 | tlsp == &tls_out ? deliver_host_address : sender_host_address); | |
607 | return 0; | |
608 | } | |
f69979cf | 609 | dn[sizeof(dn)-1] = '\0'; |
059ec3d9 | 610 | |
f4e62a87 | 611 | tlsp->verify_override = FALSE; |
f2f2c91b | 612 | if (preverify_ok == 0) |
059ec3d9 | 613 | { |
f77197ae JH |
614 | uschar * extra = verify_mode ? string_sprintf(" (during %c-verify for [%s])", |
615 | *verify_mode, sender_host_address) | |
616 | : US""; | |
617 | log_write(0, LOG_MAIN, "[%s] SSL verify error%s: depth=%d error=%s cert=%s", | |
618 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
619 | extra, depth, | |
620 | X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), dn); | |
a2ff477a | 621 | *calledp = TRUE; |
9d1c15ef JH |
622 | if (!*optionalp) |
623 | { | |
f69979cf JH |
624 | if (!tlsp->peercert) |
625 | tlsp->peercert = X509_dup(cert); /* record failing cert */ | |
626 | return 0; /* reject */ | |
9d1c15ef | 627 | } |
059ec3d9 PH |
628 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
629 | "tls_try_verify_hosts)\n"); | |
4a1bd6b9 | 630 | tlsp->verify_override = TRUE; |
059ec3d9 PH |
631 | } |
632 | ||
a7538db1 | 633 | else if (depth != 0) |
059ec3d9 | 634 | { |
f69979cf | 635 | DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, dn); |
f2de3a33 | 636 | #ifndef DISABLE_OCSP |
f5d78688 JH |
637 | if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store) |
638 | { /* client, wanting stapling */ | |
639 | /* Add the server cert's signing chain as the one | |
640 | for the verification of the OCSP stapled information. */ | |
94431adb | 641 | |
f5d78688 | 642 | if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, |
421aff85 | 643 | cert)) |
f5d78688 | 644 | ERR_clear_error(); |
c3033f13 | 645 | sk_X509_push(client_static_cbinfo->verify_stack, cert); |
f5d78688 | 646 | } |
a7538db1 | 647 | #endif |
0cbf2b82 | 648 | #ifndef DISABLE_EVENT |
f69979cf JH |
649 | if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) |
650 | return 0; /* reject, with peercert set */ | |
f5d78688 | 651 | #endif |
059ec3d9 PH |
652 | } |
653 | else | |
654 | { | |
55414b25 | 655 | const uschar * verify_cert_hostnames; |
e51c7be2 | 656 | |
e51c7be2 JH |
657 | if ( tlsp == &tls_out |
658 | && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames))) | |
afdb5e9c | 659 | /* client, wanting hostname check */ |
e51c7be2 | 660 | { |
f69979cf | 661 | |
740f36d4 | 662 | #ifdef EXIM_HAVE_OPENSSL_CHECKHOST |
f69979cf JH |
663 | # ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
664 | # define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0 | |
665 | # endif | |
666 | # ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS | |
667 | # define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0 | |
668 | # endif | |
e51c7be2 | 669 | int sep = 0; |
55414b25 | 670 | const uschar * list = verify_cert_hostnames; |
e51c7be2 | 671 | uschar * name; |
d8e7834a JH |
672 | int rc; |
673 | while ((name = string_nextinlist(&list, &sep, NULL, 0))) | |
f40d5be3 | 674 | if ((rc = X509_check_host(cert, CCS name, 0, |
8d692470 | 675 | X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
740f36d4 JH |
676 | | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS, |
677 | NULL))) | |
d8e7834a JH |
678 | { |
679 | if (rc < 0) | |
680 | { | |
93a6fce2 | 681 | log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", |
f77197ae | 682 | tlsp == &tls_out ? deliver_host_address : sender_host_address); |
d8e7834a JH |
683 | name = NULL; |
684 | } | |
e51c7be2 | 685 | break; |
d8e7834a | 686 | } |
e51c7be2 | 687 | if (!name) |
f69979cf | 688 | #else |
e51c7be2 | 689 | if (!tls_is_name_for_cert(verify_cert_hostnames, cert)) |
f69979cf | 690 | #endif |
e51c7be2 | 691 | { |
f77197ae JH |
692 | uschar * extra = verify_mode |
693 | ? string_sprintf(" (during %c-verify for [%s])", | |
694 | *verify_mode, sender_host_address) | |
695 | : US""; | |
e51c7be2 | 696 | log_write(0, LOG_MAIN, |
f77197ae JH |
697 | "[%s] SSL verify error%s: certificate name mismatch: DN=\"%s\" H=\"%s\"", |
698 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
699 | extra, dn, verify_cert_hostnames); | |
a3ef7310 JH |
700 | *calledp = TRUE; |
701 | if (!*optionalp) | |
f69979cf JH |
702 | { |
703 | if (!tlsp->peercert) | |
704 | tlsp->peercert = X509_dup(cert); /* record failing cert */ | |
705 | return 0; /* reject */ | |
706 | } | |
4a1bd6b9 | 707 | DEBUG(D_tls) debug_printf("SSL verify name failure overridden (host in " |
a3ef7310 | 708 | "tls_try_verify_hosts)\n"); |
4a1bd6b9 | 709 | tlsp->verify_override = TRUE; |
e51c7be2 | 710 | } |
f69979cf | 711 | } |
e51c7be2 | 712 | |
0cbf2b82 | 713 | #ifndef DISABLE_EVENT |
f69979cf JH |
714 | if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) |
715 | return 0; /* reject, with peercert set */ | |
e51c7be2 JH |
716 | #endif |
717 | ||
93dcb1c2 | 718 | DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n", |
f69979cf | 719 | *calledp ? "" : " authenticated", dn); |
93dcb1c2 | 720 | *calledp = TRUE; |
059ec3d9 PH |
721 | } |
722 | ||
a7538db1 | 723 | return 1; /* accept, at least for this level */ |
059ec3d9 PH |
724 | } |
725 | ||
a2ff477a | 726 | static int |
f2f2c91b | 727 | verify_callback_client(int preverify_ok, X509_STORE_CTX *x509ctx) |
a2ff477a | 728 | { |
f2f2c91b JH |
729 | return verify_callback(preverify_ok, x509ctx, &tls_out, |
730 | &client_verify_callback_called, &client_verify_optional); | |
a2ff477a JH |
731 | } |
732 | ||
733 | static int | |
f2f2c91b | 734 | verify_callback_server(int preverify_ok, X509_STORE_CTX *x509ctx) |
a2ff477a | 735 | { |
f2f2c91b JH |
736 | return verify_callback(preverify_ok, x509ctx, &tls_in, |
737 | &server_verify_callback_called, &server_verify_optional); | |
a2ff477a JH |
738 | } |
739 | ||
059ec3d9 | 740 | |
c0635b6d | 741 | #ifdef SUPPORT_DANE |
53a7196b | 742 | |
e5cccda9 JH |
743 | /* This gets called *by* the dane library verify callback, which interposes |
744 | itself. | |
745 | */ | |
746 | static int | |
f2f2c91b | 747 | verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx) |
e5cccda9 JH |
748 | { |
749 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); | |
f69979cf | 750 | uschar dn[256]; |
83b27293 | 751 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
5c75db2e | 752 | #ifndef DISABLE_EVENT |
f69979cf | 753 | BOOL dummy_called, optional = FALSE; |
83b27293 | 754 | #endif |
e5cccda9 | 755 | |
70e384dd JH |
756 | if (!X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn))) |
757 | { | |
758 | DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); | |
759 | log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", | |
760 | deliver_host_address); | |
761 | return 0; | |
762 | } | |
f69979cf | 763 | dn[sizeof(dn)-1] = '\0'; |
e5cccda9 | 764 | |
f2f2c91b JH |
765 | DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n", |
766 | preverify_ok ? "ok":"BAD", depth, dn); | |
e5cccda9 | 767 | |
0cbf2b82 | 768 | #ifndef DISABLE_EVENT |
f69979cf JH |
769 | if (verify_event(&tls_out, cert, depth, dn, |
770 | &dummy_called, &optional, US"DANE")) | |
771 | return 0; /* reject, with peercert set */ | |
83b27293 JH |
772 | #endif |
773 | ||
f2f2c91b | 774 | if (preverify_ok == 1) |
6fbf3599 | 775 | { |
4a1bd6b9 | 776 | tls_out.dane_verified = TRUE; |
6fbf3599 JH |
777 | #ifndef DISABLE_OCSP |
778 | if (client_static_cbinfo->u_ocsp.client.verify_store) | |
779 | { /* client, wanting stapling */ | |
780 | /* Add the server cert's signing chain as the one | |
781 | for the verification of the OCSP stapled information. */ | |
782 | ||
783 | if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, | |
784 | cert)) | |
785 | ERR_clear_error(); | |
786 | sk_X509_push(client_static_cbinfo->verify_stack, cert); | |
787 | } | |
788 | #endif | |
789 | } | |
f2f2c91b JH |
790 | else |
791 | { | |
792 | int err = X509_STORE_CTX_get_error(x509ctx); | |
793 | DEBUG(D_tls) | |
794 | debug_printf(" - err %d '%s'\n", err, X509_verify_cert_error_string(err)); | |
3c51463e | 795 | if (err == X509_V_ERR_APPLICATION_VERIFICATION) |
f2f2c91b JH |
796 | preverify_ok = 1; |
797 | } | |
798 | return preverify_ok; | |
e5cccda9 | 799 | } |
53a7196b | 800 | |
c0635b6d | 801 | #endif /*SUPPORT_DANE*/ |
e5cccda9 | 802 | |
059ec3d9 PH |
803 | |
804 | /************************************************* | |
805 | * Information callback * | |
806 | *************************************************/ | |
807 | ||
808 | /* The SSL library functions call this from time to time to indicate what they | |
7be682ca PP |
809 | are doing. We copy the string to the debugging output when TLS debugging has |
810 | been requested. | |
059ec3d9 PH |
811 | |
812 | Arguments: | |
813 | s the SSL connection | |
814 | where | |
815 | ret | |
816 | ||
817 | Returns: nothing | |
818 | */ | |
819 | ||
820 | static void | |
821 | info_callback(SSL *s, int where, int ret) | |
822 | { | |
0abc5a13 JH |
823 | DEBUG(D_tls) |
824 | { | |
825 | const uschar * str; | |
826 | ||
827 | if (where & SSL_ST_CONNECT) | |
48224640 | 828 | str = US"SSL_connect"; |
0abc5a13 | 829 | else if (where & SSL_ST_ACCEPT) |
48224640 | 830 | str = US"SSL_accept"; |
0abc5a13 | 831 | else |
48224640 | 832 | str = US"SSL info (undefined)"; |
0abc5a13 JH |
833 | |
834 | if (where & SSL_CB_LOOP) | |
835 | debug_printf("%s: %s\n", str, SSL_state_string_long(s)); | |
836 | else if (where & SSL_CB_ALERT) | |
837 | debug_printf("SSL3 alert %s:%s:%s\n", | |
48224640 | 838 | str = where & SSL_CB_READ ? US"read" : US"write", |
0abc5a13 JH |
839 | SSL_alert_type_string_long(ret), SSL_alert_desc_string_long(ret)); |
840 | else if (where & SSL_CB_EXIT) | |
841 | if (ret == 0) | |
842 | debug_printf("%s: failed in %s\n", str, SSL_state_string_long(s)); | |
843 | else if (ret < 0) | |
844 | debug_printf("%s: error in %s\n", str, SSL_state_string_long(s)); | |
845 | else if (where & SSL_CB_HANDSHAKE_START) | |
846 | debug_printf("%s: hshake start: %s\n", str, SSL_state_string_long(s)); | |
847 | else if (where & SSL_CB_HANDSHAKE_DONE) | |
848 | debug_printf("%s: hshake done: %s\n", str, SSL_state_string_long(s)); | |
849 | } | |
059ec3d9 PH |
850 | } |
851 | ||
8238bc7b | 852 | #ifdef OPENSSL_HAVE_KEYLOG_CB |
8a40db1c JH |
853 | static void |
854 | keylog_callback(const SSL *ssl, const char *line) | |
855 | { | |
2e5d9e71 JH |
856 | char * filename; |
857 | FILE * fp; | |
8a40db1c | 858 | DEBUG(D_tls) debug_printf("%.200s\n", line); |
2e5d9e71 JH |
859 | if (!(filename = getenv("SSLKEYLOGFILE"))) return; |
860 | if (!(fp = fopen(filename, "a"))) return; | |
861 | fprintf(fp, "%s\n", line); | |
862 | fclose(fp); | |
8a40db1c | 863 | } |
8238bc7b | 864 | #endif |
8a40db1c | 865 | |
059ec3d9 | 866 | |
b10c87b3 JH |
867 | #ifdef EXPERIMENTAL_TLS_RESUME |
868 | /* Manage the keysets used for encrypting the session tickets, on the server. */ | |
869 | ||
870 | typedef struct { /* Session ticket encryption key */ | |
871 | uschar name[16]; | |
872 | ||
873 | const EVP_CIPHER * aes_cipher; | |
4d93129f | 874 | uschar aes_key[32]; /* size needed depends on cipher. aes_128 implies 128/8 = 16? */ |
b10c87b3 JH |
875 | const EVP_MD * hmac_hash; |
876 | uschar hmac_key[16]; | |
877 | time_t renew; | |
878 | time_t expire; | |
879 | } exim_stek; | |
880 | ||
4d93129f JH |
881 | static exim_stek exim_tk; /* current key */ |
882 | static exim_stek exim_tk_old; /* previous key */ | |
b10c87b3 JH |
883 | |
884 | static void | |
885 | tk_init(void) | |
886 | { | |
4d93129f JH |
887 | time_t t = time(NULL); |
888 | ||
b10c87b3 JH |
889 | if (exim_tk.name[0]) |
890 | { | |
4d93129f | 891 | if (exim_tk.renew >= t) return; |
b10c87b3 JH |
892 | exim_tk_old = exim_tk; |
893 | } | |
894 | ||
895 | if (f.running_in_test_harness) ssl_session_timeout = 6; | |
896 | ||
897 | DEBUG(D_tls) debug_printf("OpenSSL: %s STEK\n", exim_tk.name[0] ? "rotating" : "creating"); | |
898 | if (RAND_bytes(exim_tk.aes_key, sizeof(exim_tk.aes_key)) <= 0) return; | |
899 | if (RAND_bytes(exim_tk.hmac_key, sizeof(exim_tk.hmac_key)) <= 0) return; | |
900 | if (RAND_bytes(exim_tk.name+1, sizeof(exim_tk.name)-1) <= 0) return; | |
901 | ||
902 | exim_tk.name[0] = 'E'; | |
4d93129f | 903 | exim_tk.aes_cipher = EVP_aes_256_cbc(); |
b10c87b3 | 904 | exim_tk.hmac_hash = EVP_sha256(); |
4d93129f JH |
905 | exim_tk.expire = t + ssl_session_timeout; |
906 | exim_tk.renew = t + ssl_session_timeout/2; | |
b10c87b3 JH |
907 | } |
908 | ||
909 | static exim_stek * | |
910 | tk_current(void) | |
911 | { | |
912 | if (!exim_tk.name[0]) return NULL; | |
913 | return &exim_tk; | |
914 | } | |
915 | ||
916 | static exim_stek * | |
917 | tk_find(const uschar * name) | |
918 | { | |
919 | return memcmp(name, exim_tk.name, sizeof(exim_tk.name)) == 0 ? &exim_tk | |
920 | : memcmp(name, exim_tk_old.name, sizeof(exim_tk_old.name)) == 0 ? &exim_tk_old | |
921 | : NULL; | |
922 | } | |
923 | ||
924 | /* Callback for session tickets, on server */ | |
925 | static int | |
926 | ticket_key_callback(SSL * ssl, uschar key_name[16], | |
927 | uschar * iv, EVP_CIPHER_CTX * ctx, HMAC_CTX * hctx, int enc) | |
928 | { | |
929 | tls_support * tlsp = server_static_cbinfo->tlsp; | |
930 | exim_stek * key; | |
931 | ||
932 | if (enc) | |
933 | { | |
934 | DEBUG(D_tls) debug_printf("ticket_key_callback: create new session\n"); | |
935 | tlsp->resumption |= RESUME_CLIENT_REQUESTED; | |
936 | ||
937 | if (RAND_bytes(iv, EVP_MAX_IV_LENGTH) <= 0) | |
938 | return -1; /* insufficient random */ | |
939 | ||
940 | if (!(key = tk_current())) /* current key doesn't exist or isn't valid */ | |
941 | return 0; /* key couldn't be created */ | |
942 | memcpy(key_name, key->name, 16); | |
d70fc283 | 943 | DEBUG(D_tls) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - time(NULL)); |
b10c87b3 JH |
944 | |
945 | /*XXX will want these dependent on the ssl session strength */ | |
946 | HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key), | |
947 | key->hmac_hash, NULL); | |
948 | EVP_EncryptInit_ex(ctx, key->aes_cipher, NULL, key->aes_key, iv); | |
949 | ||
950 | DEBUG(D_tls) debug_printf("ticket created\n"); | |
951 | return 1; | |
952 | } | |
953 | else | |
954 | { | |
955 | time_t now = time(NULL); | |
956 | ||
957 | DEBUG(D_tls) debug_printf("ticket_key_callback: retrieve session\n"); | |
958 | tlsp->resumption |= RESUME_CLIENT_SUGGESTED; | |
959 | ||
960 | if (!(key = tk_find(key_name)) || key->expire < now) | |
961 | { | |
962 | DEBUG(D_tls) | |
963 | { | |
964 | debug_printf("ticket not usable (%s)\n", key ? "expired" : "not found"); | |
d70fc283 | 965 | if (key) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - now); |
b10c87b3 JH |
966 | } |
967 | return 0; | |
968 | } | |
969 | ||
970 | HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key), | |
971 | key->hmac_hash, NULL); | |
972 | EVP_DecryptInit_ex(ctx, key->aes_cipher, NULL, key->aes_key, iv); | |
973 | ||
d70fc283 | 974 | DEBUG(D_tls) debug_printf("ticket usable, STEK expire " TIME_T_FMT "\n", key->expire - now); |
dea4b568 JH |
975 | |
976 | /* The ticket lifetime and renewal are the same as the STEK lifetime and | |
977 | renewal, which is overenthusiastic. A factor of, say, 3x longer STEK would | |
978 | be better. To do that we'd have to encode ticket lifetime in the name as | |
979 | we don't yet see the restored session. Could check posthandshake for TLS1.3 | |
980 | and trigger a new ticket then, but cannot do that for TLS1.2 */ | |
b10c87b3 JH |
981 | return key->renew < now ? 2 : 1; |
982 | } | |
983 | } | |
984 | #endif | |
985 | ||
986 | ||
059ec3d9 PH |
987 | |
988 | /************************************************* | |
989 | * Initialize for DH * | |
990 | *************************************************/ | |
991 | ||
992 | /* If dhparam is set, expand it, and load up the parameters for DH encryption. | |
993 | ||
994 | Arguments: | |
038597d2 | 995 | sctx The current SSL CTX (inbound or outbound) |
a799883d | 996 | dhparam DH parameter file or fixed parameter identity string |
7199e1ee | 997 | host connected host, if client; NULL if server |
cf0c6164 | 998 | errstr error string pointer |
059ec3d9 PH |
999 | |
1000 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
1001 | */ | |
1002 | ||
1003 | static BOOL | |
cf0c6164 | 1004 | init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host, uschar ** errstr) |
059ec3d9 | 1005 | { |
059ec3d9 PH |
1006 | BIO *bio; |
1007 | DH *dh; | |
1008 | uschar *dhexpanded; | |
a799883d | 1009 | const char *pem; |
6600985a | 1010 | int dh_bitsize; |
059ec3d9 | 1011 | |
cf0c6164 | 1012 | if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded, errstr)) |
059ec3d9 PH |
1013 | return FALSE; |
1014 | ||
0df4ab80 | 1015 | if (!dhexpanded || !*dhexpanded) |
a799883d | 1016 | bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1); |
a799883d | 1017 | else if (dhexpanded[0] == '/') |
059ec3d9 | 1018 | { |
0df4ab80 | 1019 | if (!(bio = BIO_new_file(CS dhexpanded, "r"))) |
059ec3d9 | 1020 | { |
7199e1ee | 1021 | tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), |
cf0c6164 | 1022 | host, US strerror(errno), errstr); |
a799883d | 1023 | return FALSE; |
059ec3d9 | 1024 | } |
a799883d PP |
1025 | } |
1026 | else | |
1027 | { | |
1028 | if (Ustrcmp(dhexpanded, "none") == 0) | |
059ec3d9 | 1029 | { |
a799883d PP |
1030 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); |
1031 | return TRUE; | |
059ec3d9 | 1032 | } |
a799883d | 1033 | |
0df4ab80 | 1034 | if (!(pem = std_dh_prime_named(dhexpanded))) |
a799883d PP |
1035 | { |
1036 | tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded), | |
cf0c6164 | 1037 | host, US strerror(errno), errstr); |
a799883d PP |
1038 | return FALSE; |
1039 | } | |
1040 | bio = BIO_new_mem_buf(CS pem, -1); | |
1041 | } | |
1042 | ||
0df4ab80 | 1043 | if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL))) |
a799883d | 1044 | { |
059ec3d9 | 1045 | BIO_free(bio); |
a799883d | 1046 | tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded), |
cf0c6164 | 1047 | host, NULL, errstr); |
a799883d PP |
1048 | return FALSE; |
1049 | } | |
1050 | ||
6600985a PP |
1051 | /* note: our default limit of 2236 is not a multiple of 8; the limit comes from |
1052 | * an NSS limit, and the GnuTLS APIs handle bit-sizes fine, so we went with | |
1053 | * 2236. But older OpenSSL can only report in bytes (octets), not bits. | |
1054 | * If someone wants to dance at the edge, then they can raise the limit or use | |
1055 | * current libraries. */ | |
1056 | #ifdef EXIM_HAVE_OPENSSL_DH_BITS | |
1057 | /* Added in commit 26c79d5641d; `git describe --contains` says OpenSSL_1_1_0-pre1~1022 | |
1058 | * This predates OpenSSL_1_1_0 (before a, b, ...) so is in all 1.1.0 */ | |
1059 | dh_bitsize = DH_bits(dh); | |
1060 | #else | |
1061 | dh_bitsize = 8 * DH_size(dh); | |
1062 | #endif | |
1063 | ||
a799883d PP |
1064 | /* Even if it is larger, we silently return success rather than cause things |
1065 | * to fail out, so that a too-large DH will not knock out all TLS; it's a | |
1066 | * debatable choice. */ | |
6600985a | 1067 | if (dh_bitsize > tls_dh_max_bits) |
a799883d PP |
1068 | { |
1069 | DEBUG(D_tls) | |
170f4904 | 1070 | debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d\n", |
6600985a | 1071 | dh_bitsize, tls_dh_max_bits); |
a799883d PP |
1072 | } |
1073 | else | |
1074 | { | |
1075 | SSL_CTX_set_tmp_dh(sctx, dh); | |
1076 | DEBUG(D_tls) | |
1077 | debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n", | |
6600985a | 1078 | dhexpanded ? dhexpanded : US"default", dh_bitsize); |
059ec3d9 PH |
1079 | } |
1080 | ||
a799883d PP |
1081 | DH_free(dh); |
1082 | BIO_free(bio); | |
1083 | ||
1084 | return TRUE; | |
059ec3d9 PH |
1085 | } |
1086 | ||
1087 | ||
1088 | ||
1089 | ||
038597d2 PP |
1090 | /************************************************* |
1091 | * Initialize for ECDH * | |
1092 | *************************************************/ | |
1093 | ||
1094 | /* Load parameters for ECDH encryption. | |
1095 | ||
1096 | For now, we stick to NIST P-256 because: it's simple and easy to configure; | |
1097 | it avoids any patent issues that might bite redistributors; despite events in | |
1098 | the news and concerns over curve choices, we're not cryptographers, we're not | |
1099 | pretending to be, and this is "good enough" to be better than no support, | |
1100 | protecting against most adversaries. Given another year or two, there might | |
1101 | be sufficient clarity about a "right" way forward to let us make an informed | |
1102 | decision, instead of a knee-jerk reaction. | |
1103 | ||
1104 | Longer-term, we should look at supporting both various named curves and | |
1105 | external files generated with "openssl ecparam", much as we do for init_dh(). | |
1106 | We should also support "none" as a value, to explicitly avoid initialisation. | |
1107 | ||
1108 | Patches welcome. | |
1109 | ||
1110 | Arguments: | |
1111 | sctx The current SSL CTX (inbound or outbound) | |
1112 | host connected host, if client; NULL if server | |
cf0c6164 | 1113 | errstr error string pointer |
038597d2 PP |
1114 | |
1115 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
1116 | */ | |
1117 | ||
1118 | static BOOL | |
cf0c6164 | 1119 | init_ecdh(SSL_CTX * sctx, host_item * host, uschar ** errstr) |
038597d2 | 1120 | { |
63f0dbe0 JH |
1121 | #ifdef OPENSSL_NO_ECDH |
1122 | return TRUE; | |
1123 | #else | |
1124 | ||
10ca4f1c JH |
1125 | EC_KEY * ecdh; |
1126 | uschar * exp_curve; | |
1127 | int nid; | |
1128 | BOOL rv; | |
1129 | ||
038597d2 PP |
1130 | if (host) /* No ECDH setup for clients, only for servers */ |
1131 | return TRUE; | |
1132 | ||
10ca4f1c | 1133 | # ifndef EXIM_HAVE_ECDH |
038597d2 PP |
1134 | DEBUG(D_tls) |
1135 | debug_printf("No OpenSSL API to define ECDH parameters, skipping\n"); | |
1136 | return TRUE; | |
038597d2 | 1137 | # else |
10ca4f1c | 1138 | |
cf0c6164 | 1139 | if (!expand_check(tls_eccurve, US"tls_eccurve", &exp_curve, errstr)) |
10ca4f1c JH |
1140 | return FALSE; |
1141 | if (!exp_curve || !*exp_curve) | |
1142 | return TRUE; | |
1143 | ||
8e53a4fc | 1144 | /* "auto" needs to be handled carefully. |
4c04137d | 1145 | * OpenSSL < 1.0.2: we do not select anything, but fallback to prime256v1 |
8e53a4fc | 1146 | * OpenSSL < 1.1.0: we have to call SSL_CTX_set_ecdh_auto |
4c04137d | 1147 | * (openssl/ssl.h defines SSL_CTRL_SET_ECDH_AUTO) |
8e53a4fc HSHR |
1148 | * OpenSSL >= 1.1.0: we do not set anything, the libray does autoselection |
1149 | * https://github.com/openssl/openssl/commit/fe6ef2472db933f01b59cad82aa925736935984b | |
1150 | */ | |
10ca4f1c | 1151 | if (Ustrcmp(exp_curve, "auto") == 0) |
038597d2 | 1152 | { |
8e53a4fc | 1153 | #if OPENSSL_VERSION_NUMBER < 0x10002000L |
10ca4f1c | 1154 | DEBUG(D_tls) debug_printf( |
8e53a4fc | 1155 | "ECDH OpenSSL < 1.0.2: temp key parameter settings: overriding \"auto\" with \"prime256v1\"\n"); |
78a3bbd5 | 1156 | exp_curve = US"prime256v1"; |
8e53a4fc HSHR |
1157 | #else |
1158 | # if defined SSL_CTRL_SET_ECDH_AUTO | |
1159 | DEBUG(D_tls) debug_printf( | |
1160 | "ECDH OpenSSL 1.0.2+ temp key parameter settings: autoselection\n"); | |
10ca4f1c JH |
1161 | SSL_CTX_set_ecdh_auto(sctx, 1); |
1162 | return TRUE; | |
8e53a4fc HSHR |
1163 | # else |
1164 | DEBUG(D_tls) debug_printf( | |
1165 | "ECDH OpenSSL 1.1.0+ temp key parameter settings: default selection\n"); | |
1166 | return TRUE; | |
1167 | # endif | |
1168 | #endif | |
10ca4f1c | 1169 | } |
038597d2 | 1170 | |
10ca4f1c JH |
1171 | DEBUG(D_tls) debug_printf("ECDH: curve '%s'\n", exp_curve); |
1172 | if ( (nid = OBJ_sn2nid (CCS exp_curve)) == NID_undef | |
1173 | # ifdef EXIM_HAVE_OPENSSL_EC_NIST2NID | |
1174 | && (nid = EC_curve_nist2nid(CCS exp_curve)) == NID_undef | |
1175 | # endif | |
1176 | ) | |
1177 | { | |
cf0c6164 JH |
1178 | tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", exp_curve), |
1179 | host, NULL, errstr); | |
10ca4f1c JH |
1180 | return FALSE; |
1181 | } | |
038597d2 | 1182 | |
10ca4f1c JH |
1183 | if (!(ecdh = EC_KEY_new_by_curve_name(nid))) |
1184 | { | |
cf0c6164 | 1185 | tls_error(US"Unable to create ec curve", host, NULL, errstr); |
10ca4f1c | 1186 | return FALSE; |
038597d2 | 1187 | } |
10ca4f1c JH |
1188 | |
1189 | /* The "tmp" in the name here refers to setting a temporary key | |
1190 | not to the stability of the interface. */ | |
1191 | ||
1192 | if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0)) | |
cf0c6164 | 1193 | tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), host, NULL, errstr); |
10ca4f1c JH |
1194 | else |
1195 | DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve); | |
1196 | ||
1197 | EC_KEY_free(ecdh); | |
1198 | return !rv; | |
1199 | ||
1200 | # endif /*EXIM_HAVE_ECDH*/ | |
1201 | #endif /*OPENSSL_NO_ECDH*/ | |
038597d2 PP |
1202 | } |
1203 | ||
1204 | ||
1205 | ||
1206 | ||
f2de3a33 | 1207 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1208 | /************************************************* |
1209 | * Load OCSP information into state * | |
1210 | *************************************************/ | |
f5d78688 | 1211 | /* Called to load the server OCSP response from the given file into memory, once |
3f7eeb86 PP |
1212 | caller has determined this is needed. Checks validity. Debugs a message |
1213 | if invalid. | |
1214 | ||
1215 | ASSUMES: single response, for single cert. | |
1216 | ||
1217 | Arguments: | |
1218 | sctx the SSL_CTX* to update | |
1219 | cbinfo various parts of session state | |
5b2fd993 | 1220 | filename the filename putatively holding an OCSP response |
86ede124 | 1221 | is_pem file is PEM format; otherwise is DER |
3f7eeb86 PP |
1222 | |
1223 | */ | |
1224 | ||
1225 | static void | |
5b2fd993 | 1226 | ocsp_load_response(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, |
86ede124 | 1227 | const uschar * filename, BOOL is_pem) |
3f7eeb86 | 1228 | { |
ee5b1e28 JH |
1229 | BIO * bio; |
1230 | OCSP_RESPONSE * resp; | |
1231 | OCSP_BASICRESP * basic_response; | |
1232 | OCSP_SINGLERESP * single_response; | |
1233 | ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd; | |
ee5b1e28 | 1234 | STACK_OF(X509) * sk; |
3f7eeb86 PP |
1235 | unsigned long verify_flags; |
1236 | int status, reason, i; | |
1237 | ||
86ede124 JH |
1238 | DEBUG(D_tls) |
1239 | debug_printf("tls_ocsp_file (%s) '%s'\n", is_pem ? "PEM" : "DER", filename); | |
3f7eeb86 | 1240 | |
5b2fd993 | 1241 | if (!(bio = BIO_new_file(CS filename, "rb"))) |
3f7eeb86 PP |
1242 | { |
1243 | DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", | |
5b2fd993 | 1244 | filename); |
3f7eeb86 PP |
1245 | return; |
1246 | } | |
1247 | ||
86ede124 JH |
1248 | if (is_pem) |
1249 | { | |
1250 | uschar * data, * freep; | |
1251 | char * dummy; | |
1252 | long len; | |
1253 | if (!PEM_read_bio(bio, &dummy, &dummy, &data, &len)) | |
1254 | { | |
1255 | DEBUG(D_tls) debug_printf("Failed to read PEM file \"%s\"\n", | |
1256 | filename); | |
1257 | return; | |
1258 | } | |
1259 | debug_printf("read pem file\n"); | |
1260 | freep = data; | |
1261 | resp = d2i_OCSP_RESPONSE(NULL, CUSS &data, len); | |
1262 | OPENSSL_free(freep); | |
1263 | } | |
1264 | else | |
1265 | resp = d2i_OCSP_RESPONSE_bio(bio, NULL); | |
3f7eeb86 | 1266 | BIO_free(bio); |
86ede124 | 1267 | |
3f7eeb86 PP |
1268 | if (!resp) |
1269 | { | |
1270 | DEBUG(D_tls) debug_printf("Error reading OCSP response.\n"); | |
1271 | return; | |
1272 | } | |
1273 | ||
ee5b1e28 | 1274 | if ((status = OCSP_response_status(resp)) != OCSP_RESPONSE_STATUS_SUCCESSFUL) |
3f7eeb86 PP |
1275 | { |
1276 | DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", | |
1277 | OCSP_response_status_str(status), status); | |
f5d78688 | 1278 | goto bad; |
3f7eeb86 PP |
1279 | } |
1280 | ||
5b2fd993 JH |
1281 | #ifdef notdef |
1282 | { | |
1283 | BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE); | |
1284 | OCSP_RESPONSE_print(bp, resp, 0); /* extreme debug: stapling content */ | |
1285 | BIO_free(bp); | |
1286 | } | |
1287 | #endif | |
1288 | ||
ee5b1e28 | 1289 | if (!(basic_response = OCSP_response_get1_basic(resp))) |
3f7eeb86 PP |
1290 | { |
1291 | DEBUG(D_tls) | |
1292 | debug_printf("OCSP response parse error: unable to extract basic response.\n"); | |
f5d78688 | 1293 | goto bad; |
3f7eeb86 PP |
1294 | } |
1295 | ||
c3033f13 | 1296 | sk = cbinfo->verify_stack; |
3f7eeb86 PP |
1297 | verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ |
1298 | ||
1299 | /* May need to expose ability to adjust those flags? | |
1300 | OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT | |
1301 | OCSP_TRUSTOTHER OCSP_NOINTERN */ | |
1302 | ||
4c04137d | 1303 | /* This does a full verify on the OCSP proof before we load it for serving |
ee5b1e28 JH |
1304 | up; possibly overkill - just date-checks might be nice enough. |
1305 | ||
1306 | OCSP_basic_verify takes a "store" arg, but does not | |
1307 | use it for the chain verification, which is all we do | |
1308 | when OCSP_NOVERIFY is set. The content from the wire | |
1309 | "basic_response" and a cert-stack "sk" are all that is used. | |
1310 | ||
c3033f13 JH |
1311 | We have a stack, loaded in setup_certs() if tls_verify_certificates |
1312 | was a file (not a directory, or "system"). It is unfortunate we | |
1313 | cannot used the connection context store, as that would neatly | |
1314 | handle the "system" case too, but there seems to be no library | |
1315 | function for getting a stack from a store. | |
e3555426 | 1316 | [ In OpenSSL 1.1 - ? X509_STORE_CTX_get0_chain(ctx) ? ] |
c3033f13 JH |
1317 | We do not free the stack since it could be needed a second time for |
1318 | SNI handling. | |
1319 | ||
4c04137d | 1320 | Separately we might try to replace using OCSP_basic_verify() - which seems to not |
5ec37a55 | 1321 | be a public interface into the OpenSSL library (there's no manual entry) - |
ee5b1e28 | 1322 | But what with? We also use OCSP_basic_verify in the client stapling callback. |
4c04137d | 1323 | And there we NEED it; we must verify that status... unless the |
ee5b1e28 JH |
1324 | library does it for us anyway? */ |
1325 | ||
1326 | if ((i = OCSP_basic_verify(basic_response, sk, NULL, verify_flags)) < 0) | |
3f7eeb86 | 1327 | { |
ee5b1e28 JH |
1328 | DEBUG(D_tls) |
1329 | { | |
0abc5a13 | 1330 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
3f7eeb86 | 1331 | debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); |
f5d78688 JH |
1332 | } |
1333 | goto bad; | |
3f7eeb86 PP |
1334 | } |
1335 | ||
1336 | /* Here's the simplifying assumption: there's only one response, for the | |
1337 | one certificate we use, and nothing for anything else in a chain. If this | |
1338 | proves false, we need to extract a cert id from our issued cert | |
1339 | (tls_certificate) and use that for OCSP_resp_find_status() (which finds the | |
1340 | right cert in the stack and then calls OCSP_single_get0_status()). | |
1341 | ||
5b2fd993 JH |
1342 | I'm hoping to avoid reworking a bunch more of how we handle state here. |
1343 | ||
1344 | XXX that will change when we add support for (TLS1.3) whole-chain stapling | |
1345 | */ | |
ee5b1e28 JH |
1346 | |
1347 | if (!(single_response = OCSP_resp_get0(basic_response, 0))) | |
3f7eeb86 PP |
1348 | { |
1349 | DEBUG(D_tls) | |
1350 | debug_printf("Unable to get first response from OCSP basic response.\n"); | |
f5d78688 | 1351 | goto bad; |
3f7eeb86 PP |
1352 | } |
1353 | ||
1354 | status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd); | |
f5d78688 | 1355 | if (status != V_OCSP_CERTSTATUS_GOOD) |
3f7eeb86 | 1356 | { |
f5d78688 JH |
1357 | DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n", |
1358 | OCSP_cert_status_str(status), status, | |
1359 | OCSP_crl_reason_str(reason), reason); | |
1360 | goto bad; | |
3f7eeb86 PP |
1361 | } |
1362 | ||
1363 | if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
1364 | { | |
1365 | DEBUG(D_tls) debug_printf("OCSP status invalid times.\n"); | |
f5d78688 | 1366 | goto bad; |
3f7eeb86 PP |
1367 | } |
1368 | ||
f5d78688 | 1369 | supply_response: |
5b2fd993 JH |
1370 | /* Add the resp to the list used by tls_server_stapling_cb() */ |
1371 | { | |
1372 | ocsp_resplist ** op = &cbinfo->u_ocsp.server.olist, * oentry; | |
1373 | while (oentry = *op) | |
1374 | op = &oentry->next; | |
1375 | *op = oentry = store_get(sizeof(ocsp_resplist), FALSE); | |
1376 | oentry->next = NULL; | |
1377 | oentry->resp = resp; | |
1378 | } | |
f5d78688 JH |
1379 | return; |
1380 | ||
1381 | bad: | |
8768d548 | 1382 | if (f.running_in_test_harness) |
018058b2 JH |
1383 | { |
1384 | extern char ** environ; | |
d7978c0f | 1385 | if (environ) for (uschar ** p = USS environ; *p; p++) |
018058b2 JH |
1386 | if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) |
1387 | { | |
1388 | DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n"); | |
1389 | goto supply_response; | |
1390 | } | |
1391 | } | |
f5d78688 | 1392 | return; |
3f7eeb86 | 1393 | } |
5b2fd993 JH |
1394 | |
1395 | ||
1396 | static void | |
1397 | ocsp_free_response_list(tls_ext_ctx_cb * cbinfo) | |
1398 | { | |
1399 | for (ocsp_resplist * olist = cbinfo->u_ocsp.server.olist; olist; | |
1400 | olist = olist->next) | |
1401 | OCSP_RESPONSE_free(olist->resp); | |
1402 | cbinfo->u_ocsp.server.olist = NULL; | |
1403 | } | |
f2de3a33 | 1404 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
1405 | |
1406 | ||
1407 | ||
1408 | ||
23bb6982 JH |
1409 | /* Create and install a selfsigned certificate, for use in server mode */ |
1410 | ||
1411 | static int | |
cf0c6164 | 1412 | tls_install_selfsign(SSL_CTX * sctx, uschar ** errstr) |
23bb6982 JH |
1413 | { |
1414 | X509 * x509 = NULL; | |
1415 | EVP_PKEY * pkey; | |
1416 | RSA * rsa; | |
1417 | X509_NAME * name; | |
1418 | uschar * where; | |
1419 | ||
1420 | where = US"allocating pkey"; | |
1421 | if (!(pkey = EVP_PKEY_new())) | |
1422 | goto err; | |
1423 | ||
1424 | where = US"allocating cert"; | |
1425 | if (!(x509 = X509_new())) | |
1426 | goto err; | |
1427 | ||
1428 | where = US"generating pkey"; | |
6aac3239 | 1429 | if (!(rsa = rsa_callback(NULL, 0, 2048))) |
23bb6982 JH |
1430 | goto err; |
1431 | ||
4c04137d | 1432 | where = US"assigning pkey"; |
23bb6982 JH |
1433 | if (!EVP_PKEY_assign_RSA(pkey, rsa)) |
1434 | goto err; | |
1435 | ||
1436 | X509_set_version(x509, 2); /* N+1 - version 3 */ | |
1613fd68 | 1437 | ASN1_INTEGER_set(X509_get_serialNumber(x509), 1); |
23bb6982 JH |
1438 | X509_gmtime_adj(X509_get_notBefore(x509), 0); |
1439 | X509_gmtime_adj(X509_get_notAfter(x509), (long)60 * 60); /* 1 hour */ | |
1440 | X509_set_pubkey(x509, pkey); | |
1441 | ||
1442 | name = X509_get_subject_name(x509); | |
1443 | X509_NAME_add_entry_by_txt(name, "C", | |
4dc2379a | 1444 | MBSTRING_ASC, CUS "UK", -1, -1, 0); |
23bb6982 | 1445 | X509_NAME_add_entry_by_txt(name, "O", |
4dc2379a | 1446 | MBSTRING_ASC, CUS "Exim Developers", -1, -1, 0); |
23bb6982 | 1447 | X509_NAME_add_entry_by_txt(name, "CN", |
4dc2379a | 1448 | MBSTRING_ASC, CUS smtp_active_hostname, -1, -1, 0); |
23bb6982 JH |
1449 | X509_set_issuer_name(x509, name); |
1450 | ||
1451 | where = US"signing cert"; | |
1452 | if (!X509_sign(x509, pkey, EVP_md5())) | |
1453 | goto err; | |
1454 | ||
1455 | where = US"installing selfsign cert"; | |
1456 | if (!SSL_CTX_use_certificate(sctx, x509)) | |
1457 | goto err; | |
1458 | ||
1459 | where = US"installing selfsign key"; | |
1460 | if (!SSL_CTX_use_PrivateKey(sctx, pkey)) | |
1461 | goto err; | |
1462 | ||
1463 | return OK; | |
1464 | ||
1465 | err: | |
cf0c6164 | 1466 | (void) tls_error(where, NULL, NULL, errstr); |
23bb6982 JH |
1467 | if (x509) X509_free(x509); |
1468 | if (pkey) EVP_PKEY_free(pkey); | |
1469 | return DEFER; | |
1470 | } | |
1471 | ||
1472 | ||
1473 | ||
1474 | ||
ba86e143 JH |
1475 | static int |
1476 | tls_add_certfile(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, uschar * file, | |
1477 | uschar ** errstr) | |
1478 | { | |
5b2fd993 | 1479 | DEBUG(D_tls) debug_printf("tls_certificate file '%s'\n", file); |
ba86e143 JH |
1480 | if (!SSL_CTX_use_certificate_chain_file(sctx, CS file)) |
1481 | return tls_error(string_sprintf( | |
1482 | "SSL_CTX_use_certificate_chain_file file=%s", file), | |
1483 | cbinfo->host, NULL, errstr); | |
1484 | return 0; | |
1485 | } | |
1486 | ||
1487 | static int | |
1488 | tls_add_pkeyfile(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, uschar * file, | |
1489 | uschar ** errstr) | |
1490 | { | |
5b2fd993 | 1491 | DEBUG(D_tls) debug_printf("tls_privatekey file '%s'\n", file); |
ba86e143 JH |
1492 | if (!SSL_CTX_use_PrivateKey_file(sctx, CS file, SSL_FILETYPE_PEM)) |
1493 | return tls_error(string_sprintf( | |
1494 | "SSL_CTX_use_PrivateKey_file file=%s", file), cbinfo->host, NULL, errstr); | |
1495 | return 0; | |
1496 | } | |
1497 | ||
1498 | ||
7be682ca PP |
1499 | /************************************************* |
1500 | * Expand key and cert file specs * | |
1501 | *************************************************/ | |
1502 | ||
f5d78688 | 1503 | /* Called once during tls_init and possibly again during TLS setup, for a |
7be682ca PP |
1504 | new context, if Server Name Indication was used and tls_sni was seen in |
1505 | the certificate string. | |
1506 | ||
1507 | Arguments: | |
1508 | sctx the SSL_CTX* to update | |
1509 | cbinfo various parts of session state | |
cf0c6164 | 1510 | errstr error string pointer |
7be682ca PP |
1511 | |
1512 | Returns: OK/DEFER/FAIL | |
1513 | */ | |
1514 | ||
1515 | static int | |
5b2fd993 | 1516 | tls_expand_session_files(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, |
cf0c6164 | 1517 | uschar ** errstr) |
7be682ca | 1518 | { |
5b2fd993 | 1519 | uschar * expanded; |
7be682ca | 1520 | |
23bb6982 | 1521 | if (!cbinfo->certificate) |
7be682ca | 1522 | { |
ba86e143 | 1523 | if (!cbinfo->is_server) /* client */ |
23bb6982 | 1524 | return OK; |
afdb5e9c | 1525 | /* server */ |
cf0c6164 | 1526 | if (tls_install_selfsign(sctx, errstr) != OK) |
23bb6982 | 1527 | return DEFER; |
7be682ca | 1528 | } |
23bb6982 JH |
1529 | else |
1530 | { | |
ba86e143 JH |
1531 | int err; |
1532 | ||
5b2fd993 JH |
1533 | if ( !reexpand_tls_files_for_sni |
1534 | && ( Ustrstr(cbinfo->certificate, US"tls_sni") | |
1535 | || Ustrstr(cbinfo->certificate, US"tls_in_sni") | |
1536 | || Ustrstr(cbinfo->certificate, US"tls_out_sni") | |
1537 | ) ) | |
23bb6982 | 1538 | reexpand_tls_files_for_sni = TRUE; |
7be682ca | 1539 | |
cf0c6164 | 1540 | if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded, errstr)) |
23bb6982 JH |
1541 | return DEFER; |
1542 | ||
ba86e143 JH |
1543 | if (expanded) |
1544 | if (cbinfo->is_server) | |
1545 | { | |
1546 | const uschar * file_list = expanded; | |
1547 | int sep = 0; | |
1548 | uschar * file; | |
5b2fd993 JH |
1549 | #ifndef DISABLE_OCSP |
1550 | const uschar * olist = cbinfo->u_ocsp.server.file; | |
1551 | int osep = 0; | |
1552 | uschar * ofile; | |
86ede124 | 1553 | BOOL fmt_pem = FALSE; |
5b2fd993 JH |
1554 | |
1555 | if (olist) | |
1556 | if (!expand_check(olist, US"tls_ocsp_file", USS &olist, errstr)) | |
1557 | return DEFER; | |
1558 | if (olist && !*olist) | |
1559 | olist = NULL; | |
1560 | ||
1561 | if ( cbinfo->u_ocsp.server.file_expanded && olist | |
1562 | && (Ustrcmp(olist, cbinfo->u_ocsp.server.file_expanded) == 0)) | |
1563 | { | |
1564 | DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n"); | |
1565 | olist = NULL; | |
1566 | } | |
1567 | else | |
1568 | { | |
1569 | ocsp_free_response_list(cbinfo); | |
1570 | cbinfo->u_ocsp.server.file_expanded = olist; | |
1571 | } | |
1572 | #endif | |
ba86e143 JH |
1573 | |
1574 | while (file = string_nextinlist(&file_list, &sep, NULL, 0)) | |
5b2fd993 | 1575 | { |
ba86e143 JH |
1576 | if ((err = tls_add_certfile(sctx, cbinfo, file, errstr))) |
1577 | return err; | |
5b2fd993 JH |
1578 | |
1579 | #ifndef DISABLE_OCSP | |
1580 | if (olist) | |
1581 | if ((ofile = string_nextinlist(&olist, &osep, NULL, 0))) | |
86ede124 JH |
1582 | { |
1583 | if (Ustrncmp(ofile, US"PEM ", 4) == 0) | |
1584 | { | |
1585 | fmt_pem = TRUE; | |
1586 | ofile += 4; | |
1587 | } | |
1588 | else if (Ustrncmp(ofile, US"DER ", 4) == 0) | |
1589 | { | |
1590 | fmt_pem = FALSE; | |
1591 | ofile += 4; | |
1592 | } | |
1593 | ocsp_load_response(sctx, cbinfo, ofile, fmt_pem); | |
1594 | } | |
5b2fd993 JH |
1595 | else |
1596 | DEBUG(D_tls) debug_printf("ran out of ocsp file list\n"); | |
1597 | #endif | |
1598 | } | |
ba86e143 JH |
1599 | } |
1600 | else /* would there ever be a need for multiple client certs? */ | |
1601 | if ((err = tls_add_certfile(sctx, cbinfo, expanded, errstr))) | |
1602 | return err; | |
7be682ca | 1603 | |
5a2a0989 JH |
1604 | if ( cbinfo->privatekey |
1605 | && !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded, errstr)) | |
23bb6982 | 1606 | return DEFER; |
7be682ca | 1607 | |
23bb6982 JH |
1608 | /* If expansion was forced to fail, key_expanded will be NULL. If the result |
1609 | of the expansion is an empty string, ignore it also, and assume the private | |
1610 | key is in the same file as the certificate. */ | |
1611 | ||
1612 | if (expanded && *expanded) | |
ba86e143 JH |
1613 | if (cbinfo->is_server) |
1614 | { | |
1615 | const uschar * file_list = expanded; | |
1616 | int sep = 0; | |
1617 | uschar * file; | |
1618 | ||
1619 | while (file = string_nextinlist(&file_list, &sep, NULL, 0)) | |
1620 | if ((err = tls_add_pkeyfile(sctx, cbinfo, file, errstr))) | |
1621 | return err; | |
1622 | } | |
1623 | else /* would there ever be a need for multiple client certs? */ | |
1624 | if ((err = tls_add_pkeyfile(sctx, cbinfo, expanded, errstr))) | |
1625 | return err; | |
7be682ca PP |
1626 | } |
1627 | ||
1628 | return OK; | |
1629 | } | |
1630 | ||
1631 | ||
1632 | ||
1633 | ||
1634 | /************************************************* | |
1635 | * Callback to handle SNI * | |
1636 | *************************************************/ | |
1637 | ||
1638 | /* Called when acting as server during the TLS session setup if a Server Name | |
1639 | Indication extension was sent by the client. | |
1640 | ||
1641 | API documentation is OpenSSL s_server.c implementation. | |
1642 | ||
1643 | Arguments: | |
1644 | s SSL* of the current session | |
1645 | ad unknown (part of OpenSSL API) (unused) | |
1646 | arg Callback of "our" registered data | |
1647 | ||
1648 | Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK} | |
b10c87b3 JH |
1649 | |
1650 | XXX might need to change to using ClientHello callback, | |
1651 | per https://www.openssl.org/docs/manmaster/man3/SSL_client_hello_cb_fn.html | |
7be682ca PP |
1652 | */ |
1653 | ||
3bcbbbe2 | 1654 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
7be682ca PP |
1655 | static int |
1656 | tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg) | |
1657 | { | |
1658 | const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); | |
3f7eeb86 | 1659 | tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; |
7be682ca | 1660 | int rc; |
3f0945ff | 1661 | int old_pool = store_pool; |
cf0c6164 | 1662 | uschar * dummy_errstr; |
7be682ca PP |
1663 | |
1664 | if (!servername) | |
1665 | return SSL_TLSEXT_ERR_OK; | |
1666 | ||
3f0945ff | 1667 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername, |
7be682ca PP |
1668 | reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)"); |
1669 | ||
1670 | /* Make the extension value available for expansion */ | |
3f0945ff | 1671 | store_pool = POOL_PERM; |
89a80675 | 1672 | tls_in.sni = string_copy_taint(US servername, TRUE); |
3f0945ff | 1673 | store_pool = old_pool; |
7be682ca PP |
1674 | |
1675 | if (!reexpand_tls_files_for_sni) | |
1676 | return SSL_TLSEXT_ERR_OK; | |
1677 | ||
1678 | /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually; | |
1679 | not confident that memcpy wouldn't break some internal reference counting. | |
1680 | Especially since there's a references struct member, which would be off. */ | |
1681 | ||
7a8b9519 JH |
1682 | #ifdef EXIM_HAVE_OPENSSL_TLS_METHOD |
1683 | if (!(server_sni = SSL_CTX_new(TLS_server_method()))) | |
1684 | #else | |
0df4ab80 | 1685 | if (!(server_sni = SSL_CTX_new(SSLv23_server_method()))) |
7a8b9519 | 1686 | #endif |
7be682ca | 1687 | { |
0abc5a13 | 1688 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
7be682ca | 1689 | DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring); |
5a2a0989 | 1690 | goto bad; |
7be682ca PP |
1691 | } |
1692 | ||
1693 | /* Not sure how many of these are actually needed, since SSL object | |
1694 | already exists. Might even need this selfsame callback, for reneg? */ | |
1695 | ||
817d9f57 JH |
1696 | SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx)); |
1697 | SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx)); | |
1698 | SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); | |
1699 | SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); | |
1700 | SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); | |
1701 | SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); | |
038597d2 | 1702 | |
cf0c6164 JH |
1703 | if ( !init_dh(server_sni, cbinfo->dhparam, NULL, &dummy_errstr) |
1704 | || !init_ecdh(server_sni, NULL, &dummy_errstr) | |
038597d2 | 1705 | ) |
5a2a0989 | 1706 | goto bad; |
038597d2 | 1707 | |
ca954d7f JH |
1708 | if ( cbinfo->server_cipher_list |
1709 | && !SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list)) | |
5a2a0989 | 1710 | goto bad; |
ca954d7f | 1711 | |
f2de3a33 | 1712 | #ifndef DISABLE_OCSP |
f5d78688 | 1713 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1714 | { |
f5d78688 | 1715 | SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb); |
14c7b357 | 1716 | SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo); |
3f7eeb86 PP |
1717 | } |
1718 | #endif | |
7be682ca | 1719 | |
c3033f13 | 1720 | if ((rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, |
cf0c6164 | 1721 | verify_callback_server, &dummy_errstr)) != OK) |
5a2a0989 | 1722 | goto bad; |
7be682ca | 1723 | |
3f7eeb86 PP |
1724 | /* do this after setup_certs, because this can require the certs for verifying |
1725 | OCSP information. */ | |
cf0c6164 | 1726 | if ((rc = tls_expand_session_files(server_sni, cbinfo, &dummy_errstr)) != OK) |
5a2a0989 | 1727 | goto bad; |
a799883d | 1728 | |
7be682ca | 1729 | DEBUG(D_tls) debug_printf("Switching SSL context.\n"); |
817d9f57 | 1730 | SSL_set_SSL_CTX(s, server_sni); |
7be682ca | 1731 | return SSL_TLSEXT_ERR_OK; |
5a2a0989 JH |
1732 | |
1733 | bad: return SSL_TLSEXT_ERR_ALERT_FATAL; | |
7be682ca | 1734 | } |
3bcbbbe2 | 1735 | #endif /* EXIM_HAVE_OPENSSL_TLSEXT */ |
7be682ca PP |
1736 | |
1737 | ||
1738 | ||
1739 | ||
f2de3a33 | 1740 | #ifndef DISABLE_OCSP |
f5d78688 | 1741 | |
3f7eeb86 PP |
1742 | /************************************************* |
1743 | * Callback to handle OCSP Stapling * | |
1744 | *************************************************/ | |
1745 | ||
1746 | /* Called when acting as server during the TLS session setup if the client | |
1747 | requests OCSP information with a Certificate Status Request. | |
1748 | ||
1749 | Documentation via openssl s_server.c and the Apache patch from the OpenSSL | |
1750 | project. | |
1751 | ||
1752 | */ | |
1753 | ||
1754 | static int | |
f5d78688 | 1755 | tls_server_stapling_cb(SSL *s, void *arg) |
3f7eeb86 | 1756 | { |
5b2fd993 JH |
1757 | const tls_ext_ctx_cb * cbinfo = (tls_ext_ctx_cb *) arg; |
1758 | ocsp_resplist * olist = cbinfo->u_ocsp.server.olist; | |
1759 | uschar * response_der; /*XXX blob */ | |
3f7eeb86 PP |
1760 | int response_der_len; |
1761 | ||
af4a1bca | 1762 | DEBUG(D_tls) |
5b2fd993 JH |
1763 | debug_printf("Received TLS status request (OCSP stapling); %s response list\n", |
1764 | olist ? "have" : "lack"); | |
f5d78688 | 1765 | |
44662487 | 1766 | tls_in.ocsp = OCSP_NOT_RESP; |
5b2fd993 | 1767 | if (!olist) |
3f7eeb86 PP |
1768 | return SSL_TLSEXT_ERR_NOACK; |
1769 | ||
012dd02e | 1770 | #ifdef EXIM_HAVE_OPESSL_GET0_SERIAL |
5b2fd993 JH |
1771 | { |
1772 | const X509 * cert_sent = SSL_get_certificate(s); | |
1773 | const ASN1_INTEGER * cert_serial = X509_get0_serialNumber(cert_sent); | |
1774 | const BIGNUM * cert_bn = ASN1_INTEGER_to_BN(cert_serial, NULL); | |
1775 | const X509_NAME * cert_issuer = X509_get_issuer_name(cert_sent); | |
1776 | uschar * chash; | |
1777 | uint chash_len; | |
1778 | ||
1779 | for (; olist; olist = olist->next) | |
1780 | { | |
1781 | OCSP_BASICRESP * bs = OCSP_response_get1_basic(olist->resp); | |
1782 | const OCSP_SINGLERESP * single = OCSP_resp_get0(bs, 0); | |
1783 | const OCSP_CERTID * cid = OCSP_SINGLERESP_get0_id(single); | |
1784 | ASN1_INTEGER * res_cert_serial; | |
1785 | const BIGNUM * resp_bn; | |
1786 | ASN1_OCTET_STRING * res_cert_iNameHash; | |
1787 | ||
1788 | ||
1789 | (void) OCSP_id_get0_info(&res_cert_iNameHash, NULL, NULL, &res_cert_serial, | |
1790 | (OCSP_CERTID *) cid); | |
1791 | resp_bn = ASN1_INTEGER_to_BN(res_cert_serial, NULL); | |
1792 | ||
1793 | DEBUG(D_tls) | |
1794 | { | |
1795 | debug_printf("cert serial: %s\n", BN_bn2hex(cert_bn)); | |
1796 | debug_printf("resp serial: %s\n", BN_bn2hex(resp_bn)); | |
1797 | } | |
1798 | ||
1799 | if (BN_cmp(cert_bn, resp_bn) == 0) | |
1800 | { | |
1801 | DEBUG(D_tls) debug_printf("matched serial for ocsp\n"); | |
1802 | ||
1803 | /*XXX TODO: check the rest of the list for duplicate matches. | |
1804 | If any, need to also check the Issuer Name hash. | |
1805 | Without this, we will provide the wrong status in the case of | |
1806 | duplicate id. */ | |
1807 | ||
1808 | break; | |
1809 | } | |
1810 | DEBUG(D_tls) debug_printf("not match serial for ocsp\n"); | |
1811 | } | |
1812 | if (!olist) | |
1813 | { | |
1814 | DEBUG(D_tls) debug_printf("failed to find match for ocsp\n"); | |
1815 | return SSL_TLSEXT_ERR_NOACK; | |
1816 | } | |
1817 | } | |
012dd02e JH |
1818 | #else |
1819 | if (olist->next) | |
1820 | { | |
1821 | DEBUG(D_tls) debug_printf("OpenSSL version too early to support multi-leaf OCSP\n"); | |
1822 | return SSL_TLSEXT_ERR_NOACK; | |
1823 | } | |
1824 | #endif | |
5b2fd993 JH |
1825 | |
1826 | /*XXX could we do the i2d earlier, rather than during the callback? */ | |
3f7eeb86 | 1827 | response_der = NULL; |
5b2fd993 | 1828 | response_der_len = i2d_OCSP_RESPONSE(olist->resp, &response_der); |
3f7eeb86 PP |
1829 | if (response_der_len <= 0) |
1830 | return SSL_TLSEXT_ERR_NOACK; | |
1831 | ||
5e55c7a9 | 1832 | SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len); |
44662487 | 1833 | tls_in.ocsp = OCSP_VFIED; |
3f7eeb86 PP |
1834 | return SSL_TLSEXT_ERR_OK; |
1835 | } | |
1836 | ||
3f7eeb86 | 1837 | |
f5d78688 JH |
1838 | static void |
1839 | time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time) | |
1840 | { | |
1841 | BIO_printf(bp, "\t%s: ", str); | |
1842 | ASN1_GENERALIZEDTIME_print(bp, time); | |
1843 | BIO_puts(bp, "\n"); | |
1844 | } | |
1845 | ||
1846 | static int | |
1847 | tls_client_stapling_cb(SSL *s, void *arg) | |
1848 | { | |
1849 | tls_ext_ctx_cb * cbinfo = arg; | |
1850 | const unsigned char * p; | |
1851 | int len; | |
1852 | OCSP_RESPONSE * rsp; | |
1853 | OCSP_BASICRESP * bs; | |
1854 | int i; | |
1855 | ||
14003634 | 1856 | DEBUG(D_tls) debug_printf("Received TLS status callback (OCSP stapling):\n"); |
f5d78688 JH |
1857 | len = SSL_get_tlsext_status_ocsp_resp(s, &p); |
1858 | if(!p) | |
1859 | { | |
44662487 | 1860 | /* Expect this when we requested ocsp but got none */ |
6c6d6e48 | 1861 | if (cbinfo->u_ocsp.client.verify_required && LOGGING(tls_cipher)) |
14003634 | 1862 | log_write(0, LOG_MAIN, "Required TLS certificate status not received"); |
f5d78688 JH |
1863 | else |
1864 | DEBUG(D_tls) debug_printf(" null\n"); | |
44662487 | 1865 | return cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 1866 | } |
018058b2 | 1867 | |
c82de233 JH |
1868 | if (!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) |
1869 | { | |
1870 | tls_out.ocsp = OCSP_FAILED; /*XXX should use tlsp-> to permit concurrent outbound */ | |
6c6d6e48 | 1871 | if (LOGGING(tls_cipher)) |
1eca31ca | 1872 | log_write(0, LOG_MAIN, "Received TLS cert status response, parse error"); |
f5d78688 JH |
1873 | else |
1874 | DEBUG(D_tls) debug_printf(" parse error\n"); | |
1875 | return 0; | |
c82de233 | 1876 | } |
f5d78688 | 1877 | |
c82de233 | 1878 | if (!(bs = OCSP_response_get1_basic(rsp))) |
f5d78688 | 1879 | { |
018058b2 | 1880 | tls_out.ocsp = OCSP_FAILED; |
6c6d6e48 | 1881 | if (LOGGING(tls_cipher)) |
1eca31ca | 1882 | log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response"); |
f5d78688 JH |
1883 | else |
1884 | DEBUG(D_tls) debug_printf(" error parsing response\n"); | |
1885 | OCSP_RESPONSE_free(rsp); | |
1886 | return 0; | |
1887 | } | |
1888 | ||
1889 | /* We'd check the nonce here if we'd put one in the request. */ | |
1890 | /* However that would defeat cacheability on the server so we don't. */ | |
1891 | ||
f5d78688 JH |
1892 | /* This section of code reworked from OpenSSL apps source; |
1893 | The OpenSSL Project retains copyright: | |
1894 | Copyright (c) 1999 The OpenSSL Project. All rights reserved. | |
1895 | */ | |
1896 | { | |
1897 | BIO * bp = NULL; | |
86ede124 JH |
1898 | #ifndef EXIM_HAVE_OCSP_RESP_COUNT |
1899 | STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; | |
1900 | #endif | |
f5d78688 | 1901 | |
57887ecc | 1902 | DEBUG(D_tls) bp = BIO_new_fp(debug_file, BIO_NOCLOSE); |
f5d78688 JH |
1903 | |
1904 | /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */ | |
1905 | ||
1906 | /* Use the chain that verified the server cert to verify the stapled info */ | |
1907 | /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */ | |
1908 | ||
c3033f13 | 1909 | if ((i = OCSP_basic_verify(bs, cbinfo->verify_stack, |
86ede124 JH |
1910 | cbinfo->u_ocsp.client.verify_store, OCSP_NOEXPLICIT)) <= 0) |
1911 | if (ERR_peek_error()) | |
1912 | { | |
1913 | tls_out.ocsp = OCSP_FAILED; | |
1914 | if (LOGGING(tls_cipher)) log_write(0, LOG_MAIN, | |
1915 | "Received TLS cert status response, itself unverifiable: %s", | |
1916 | ERR_reason_error_string(ERR_peek_error())); | |
1917 | BIO_printf(bp, "OCSP response verify failure\n"); | |
1918 | ERR_print_errors(bp); | |
1919 | OCSP_RESPONSE_print(bp, rsp, 0); | |
1920 | goto failed; | |
1921 | } | |
1922 | else | |
1923 | DEBUG(D_tls) debug_printf("no explicit trust for OCSP signing" | |
1924 | " in the root CA certificate; ignoring\n"); | |
f5d78688 | 1925 | |
86ede124 | 1926 | DEBUG(D_tls) debug_printf("OCSP response well-formed and signed OK\n"); |
f5d78688 | 1927 | |
c8dfb21d JH |
1928 | /*XXX So we have a good stapled OCSP status. How do we know |
1929 | it is for the cert of interest? OpenSSL 1.1.0 has a routine | |
1930 | OCSP_resp_find_status() which matches on a cert id, which presumably | |
1931 | we should use. Making an id needs OCSP_cert_id_new(), which takes | |
1932 | issuerName, issuerKey, serialNumber. Are they all in the cert? | |
1933 | ||
1934 | For now, carry on blindly accepting the resp. */ | |
1935 | ||
86ede124 | 1936 | for (int idx = |
c8dfb21d | 1937 | #ifdef EXIM_HAVE_OCSP_RESP_COUNT |
86ede124 | 1938 | OCSP_resp_count(bs) - 1; |
c8dfb21d | 1939 | #else |
86ede124 | 1940 | sk_OCSP_SINGLERESP_num(sresp) - 1; |
c8dfb21d | 1941 | #endif |
86ede124 JH |
1942 | idx >= 0; idx--) |
1943 | { | |
1944 | OCSP_SINGLERESP * single = OCSP_resp_get0(bs, idx); | |
1945 | int status, reason; | |
1946 | ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd; | |
1947 | ||
1948 | /*XXX so I can see putting a loop in here to handle a rsp with >1 singleresp | |
1949 | - but what happens with a GnuTLS-style input? | |
1950 | ||
1951 | we could do with a debug label for each singleresp | |
1952 | - it has a certID with a serialNumber, but I see no API to get that | |
1953 | */ | |
44662487 JH |
1954 | status = OCSP_single_get0_status(single, &reason, &rev, |
1955 | &thisupd, &nextupd); | |
f5d78688 | 1956 | |
86ede124 JH |
1957 | DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd); |
1958 | DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd); | |
1959 | if (!OCSP_check_validity(thisupd, nextupd, | |
1960 | EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
1961 | { | |
1962 | tls_out.ocsp = OCSP_FAILED; | |
1963 | DEBUG(D_tls) ERR_print_errors(bp); | |
1964 | log_write(0, LOG_MAIN, "Server OSCP dates invalid"); | |
1965 | goto failed; | |
1966 | } | |
1967 | ||
44662487 JH |
1968 | DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n", |
1969 | OCSP_cert_status_str(status)); | |
1970 | switch(status) | |
1971 | { | |
1972 | case V_OCSP_CERTSTATUS_GOOD: | |
86ede124 | 1973 | continue; /* the idx loop */ |
44662487 JH |
1974 | case V_OCSP_CERTSTATUS_REVOKED: |
1975 | log_write(0, LOG_MAIN, "Server certificate revoked%s%s", | |
1976 | reason != -1 ? "; reason: " : "", | |
1977 | reason != -1 ? OCSP_crl_reason_str(reason) : ""); | |
1978 | DEBUG(D_tls) time_print(bp, "Revocation Time", rev); | |
44662487 JH |
1979 | break; |
1980 | default: | |
1981 | log_write(0, LOG_MAIN, | |
1982 | "Server certificate status unknown, in OCSP stapling"); | |
44662487 JH |
1983 | break; |
1984 | } | |
86ede124 JH |
1985 | |
1986 | goto failed; | |
f5d78688 | 1987 | } |
86ede124 JH |
1988 | |
1989 | i = 1; | |
1990 | tls_out.ocsp = OCSP_VFIED; | |
1991 | goto good; | |
1992 | ||
c8dfb21d | 1993 | failed: |
86ede124 | 1994 | tls_out.ocsp = OCSP_FAILED; |
c8dfb21d JH |
1995 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
1996 | good: | |
f5d78688 JH |
1997 | BIO_free(bp); |
1998 | } | |
1999 | ||
2000 | OCSP_RESPONSE_free(rsp); | |
2001 | return i; | |
2002 | } | |
f2de3a33 | 2003 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
2004 | |
2005 | ||
059ec3d9 PH |
2006 | /************************************************* |
2007 | * Initialize for TLS * | |
2008 | *************************************************/ | |
2009 | ||
b038d456 JH |
2010 | static void |
2011 | tls_openssl_init(void) | |
2012 | { | |
2013 | #ifdef EXIM_NEED_OPENSSL_INIT | |
2014 | SSL_load_error_strings(); /* basic set up */ | |
2015 | OpenSSL_add_ssl_algorithms(); | |
2016 | #endif | |
2017 | ||
2018 | #if defined(EXIM_HAVE_SHA256) && !defined(OPENSSL_AUTO_SHA256) | |
2019 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the | |
2020 | list of available digests. */ | |
2021 | EVP_add_digest(EVP_sha256()); | |
2022 | #endif | |
2023 | } | |
2024 | ||
2025 | ||
2026 | ||
e51c7be2 JH |
2027 | /* Called from both server and client code, to do preliminary initialization |
2028 | of the library. We allocate and return a context structure. | |
059ec3d9 PH |
2029 | |
2030 | Arguments: | |
946ecbe0 | 2031 | ctxp returned SSL context |
059ec3d9 PH |
2032 | host connected host, if client; NULL if server |
2033 | dhparam DH parameter file | |
2034 | certificate certificate file | |
2035 | privatekey private key | |
f5d78688 | 2036 | ocsp_file file of stapling info (server); flag for require ocsp (client) |
059ec3d9 | 2037 | addr address if client; NULL if server (for some randomness) |
946ecbe0 | 2038 | cbp place to put allocated callback context |
cf0c6164 | 2039 | errstr error string pointer |
059ec3d9 PH |
2040 | |
2041 | Returns: OK/DEFER/FAIL | |
2042 | */ | |
2043 | ||
2044 | static int | |
817d9f57 | 2045 | tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate, |
3f7eeb86 | 2046 | uschar *privatekey, |
f2de3a33 | 2047 | #ifndef DISABLE_OCSP |
5b2fd993 | 2048 | uschar *ocsp_file, |
3f7eeb86 | 2049 | #endif |
b10c87b3 JH |
2050 | address_item *addr, tls_ext_ctx_cb ** cbp, |
2051 | tls_support * tlsp, | |
2052 | uschar ** errstr) | |
059ec3d9 | 2053 | { |
7006ee24 | 2054 | SSL_CTX * ctx; |
77bb000f | 2055 | long init_options; |
7be682ca | 2056 | int rc; |
a7538db1 | 2057 | tls_ext_ctx_cb * cbinfo; |
7be682ca PP |
2058 | |
2059 | cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); | |
b10c87b3 | 2060 | cbinfo->tlsp = tlsp; |
7be682ca PP |
2061 | cbinfo->certificate = certificate; |
2062 | cbinfo->privatekey = privatekey; | |
a6510420 | 2063 | cbinfo->is_server = host==NULL; |
f2de3a33 | 2064 | #ifndef DISABLE_OCSP |
c3033f13 | 2065 | cbinfo->verify_stack = NULL; |
a6510420 | 2066 | if (!host) |
f5d78688 JH |
2067 | { |
2068 | cbinfo->u_ocsp.server.file = ocsp_file; | |
2069 | cbinfo->u_ocsp.server.file_expanded = NULL; | |
5b2fd993 | 2070 | cbinfo->u_ocsp.server.olist = NULL; |
f5d78688 JH |
2071 | } |
2072 | else | |
2073 | cbinfo->u_ocsp.client.verify_store = NULL; | |
3f7eeb86 | 2074 | #endif |
7be682ca | 2075 | cbinfo->dhparam = dhparam; |
0df4ab80 | 2076 | cbinfo->server_cipher_list = NULL; |
7be682ca | 2077 | cbinfo->host = host; |
0cbf2b82 | 2078 | #ifndef DISABLE_EVENT |
a7538db1 JH |
2079 | cbinfo->event_action = NULL; |
2080 | #endif | |
77bb000f | 2081 | |
b038d456 | 2082 | tls_openssl_init(); |
a0475b69 | 2083 | |
f0f5a555 PP |
2084 | /* Create a context. |
2085 | The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant | |
2086 | negotiation in the different methods; as far as I can tell, the only | |
2087 | *_{server,client}_method which allows negotiation is SSLv23, which exists even | |
2088 | when OpenSSL is built without SSLv2 support. | |
2089 | By disabling with openssl_options, we can let admins re-enable with the | |
2090 | existing knob. */ | |
059ec3d9 | 2091 | |
7a8b9519 JH |
2092 | #ifdef EXIM_HAVE_OPENSSL_TLS_METHOD |
2093 | if (!(ctx = SSL_CTX_new(host ? TLS_client_method() : TLS_server_method()))) | |
2094 | #else | |
7006ee24 | 2095 | if (!(ctx = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method()))) |
7a8b9519 | 2096 | #endif |
7006ee24 | 2097 | return tls_error(US"SSL_CTX_new", host, NULL, errstr); |
059ec3d9 PH |
2098 | |
2099 | /* It turns out that we need to seed the random number generator this early in | |
2100 | order to get the full complement of ciphers to work. It took me roughly a day | |
2101 | of work to discover this by experiment. | |
2102 | ||
2103 | On systems that have /dev/urandom, SSL may automatically seed itself from | |
2104 | there. Otherwise, we have to make something up as best we can. Double check | |
2105 | afterwards. */ | |
2106 | ||
2107 | if (!RAND_status()) | |
2108 | { | |
2109 | randstuff r; | |
9e3331ea | 2110 | gettimeofday(&r.tv, NULL); |
059ec3d9 PH |
2111 | r.p = getpid(); |
2112 | ||
5903c6ff JH |
2113 | RAND_seed(US (&r), sizeof(r)); |
2114 | RAND_seed(US big_buffer, big_buffer_size); | |
2115 | if (addr != NULL) RAND_seed(US addr, sizeof(addr)); | |
059ec3d9 PH |
2116 | |
2117 | if (!RAND_status()) | |
7199e1ee | 2118 | return tls_error(US"RAND_status", host, |
cf0c6164 | 2119 | US"unable to seed random number generator", errstr); |
059ec3d9 PH |
2120 | } |
2121 | ||
2122 | /* Set up the information callback, which outputs if debugging is at a suitable | |
2123 | level. */ | |
2124 | ||
b10c87b3 JH |
2125 | DEBUG(D_tls) |
2126 | { | |
2127 | SSL_CTX_set_info_callback(ctx, (void (*)())info_callback); | |
e570d136 JH |
2128 | #if defined(EXIM_HAVE_OPESSL_TRACE) && !defined(OPENSSL_NO_SSL_TRACE) |
2129 | /* this needs a debug build of OpenSSL */ | |
b10c87b3 JH |
2130 | SSL_CTX_set_msg_callback(ctx, (void (*)())SSL_trace); |
2131 | #endif | |
8a40db1c | 2132 | #ifdef OPENSSL_HAVE_KEYLOG_CB |
b10c87b3 | 2133 | SSL_CTX_set_keylog_callback(ctx, (void (*)())keylog_callback); |
8a40db1c | 2134 | #endif |
b10c87b3 | 2135 | } |
059ec3d9 | 2136 | |
c80c5570 | 2137 | /* Automatically re-try reads/writes after renegotiation. */ |
7006ee24 | 2138 | (void) SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY); |
c80c5570 | 2139 | |
77bb000f PP |
2140 | /* Apply administrator-supplied work-arounds. |
2141 | Historically we applied just one requested option, | |
2142 | SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we | |
2143 | moved to an administrator-controlled list of options to specify and | |
2144 | grandfathered in the first one as the default value for "openssl_options". | |
059ec3d9 | 2145 | |
77bb000f PP |
2146 | No OpenSSL version number checks: the options we accept depend upon the |
2147 | availability of the option value macros from OpenSSL. */ | |
059ec3d9 | 2148 | |
7006ee24 | 2149 | if (!tls_openssl_options_parse(openssl_options, &init_options)) |
cf0c6164 | 2150 | return tls_error(US"openssl_options parsing failed", host, NULL, errstr); |
77bb000f | 2151 | |
b10c87b3 JH |
2152 | #ifdef EXPERIMENTAL_TLS_RESUME |
2153 | tlsp->resumption = RESUME_SUPPORTED; | |
2154 | #endif | |
77bb000f PP |
2155 | if (init_options) |
2156 | { | |
b10c87b3 JH |
2157 | #ifdef EXPERIMENTAL_TLS_RESUME |
2158 | /* Should the server offer session resumption? */ | |
2159 | if (!host && verify_check_host(&tls_resumption_hosts) == OK) | |
2160 | { | |
2161 | DEBUG(D_tls) debug_printf("tls_resumption_hosts overrides openssl_options\n"); | |
2162 | init_options &= ~SSL_OP_NO_TICKET; | |
2163 | tlsp->resumption |= RESUME_SERVER_TICKET; /* server will give ticket on request */ | |
2164 | tlsp->host_resumable = TRUE; | |
2165 | } | |
2166 | #endif | |
2167 | ||
77bb000f | 2168 | DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); |
7006ee24 | 2169 | if (!(SSL_CTX_set_options(ctx, init_options))) |
77bb000f | 2170 | return tls_error(string_sprintf( |
cf0c6164 | 2171 | "SSL_CTX_set_option(%#lx)", init_options), host, NULL, errstr); |
77bb000f PP |
2172 | } |
2173 | else | |
2174 | DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); | |
059ec3d9 | 2175 | |
a28050f8 JH |
2176 | /* We'd like to disable session cache unconditionally, but foolish Outlook |
2177 | Express clients then give up the first TLS connection and make a second one | |
2178 | (which works). Only when there is an IMAP service on the same machine. | |
2179 | Presumably OE is trying to use the cache for A on B. Leave it enabled for | |
2180 | now, until we work out a decent way of presenting control to the config. It | |
2181 | will never be used because we use a new context every time. */ | |
2182 | #ifdef notdef | |
7006ee24 | 2183 | (void) SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF); |
a28050f8 | 2184 | #endif |
7006ee24 | 2185 | |
059ec3d9 | 2186 | /* Initialize with DH parameters if supplied */ |
10ca4f1c | 2187 | /* Initialize ECDH temp key parameter selection */ |
059ec3d9 | 2188 | |
7006ee24 JH |
2189 | if ( !init_dh(ctx, dhparam, host, errstr) |
2190 | || !init_ecdh(ctx, host, errstr) | |
038597d2 PP |
2191 | ) |
2192 | return DEFER; | |
059ec3d9 | 2193 | |
3f7eeb86 | 2194 | /* Set up certificate and key (and perhaps OCSP info) */ |
059ec3d9 | 2195 | |
7006ee24 | 2196 | if ((rc = tls_expand_session_files(ctx, cbinfo, errstr)) != OK) |
23bb6982 | 2197 | return rc; |
c91535f3 | 2198 | |
c3033f13 JH |
2199 | /* If we need to handle SNI or OCSP, do so */ |
2200 | ||
3bcbbbe2 | 2201 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
c3033f13 JH |
2202 | # ifndef DISABLE_OCSP |
2203 | if (!(cbinfo->verify_stack = sk_X509_new_null())) | |
2204 | { | |
2205 | DEBUG(D_tls) debug_printf("failed to create stack for stapling verify\n"); | |
2206 | return FAIL; | |
2207 | } | |
2208 | # endif | |
2209 | ||
7a8b9519 | 2210 | if (!host) /* server */ |
3f0945ff | 2211 | { |
f2de3a33 | 2212 | # ifndef DISABLE_OCSP |
5b2fd993 | 2213 | /* We check u_ocsp.server.file, not server.olist, because we care about if |
3f7eeb86 PP |
2214 | the option exists, not what the current expansion might be, as SNI might |
2215 | change the certificate and OCSP file in use between now and the time the | |
2216 | callback is invoked. */ | |
f5d78688 | 2217 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 2218 | { |
7006ee24 JH |
2219 | SSL_CTX_set_tlsext_status_cb(ctx, tls_server_stapling_cb); |
2220 | SSL_CTX_set_tlsext_status_arg(ctx, cbinfo); | |
3f7eeb86 | 2221 | } |
f5d78688 | 2222 | # endif |
3f0945ff PP |
2223 | /* We always do this, so that $tls_sni is available even if not used in |
2224 | tls_certificate */ | |
7006ee24 JH |
2225 | SSL_CTX_set_tlsext_servername_callback(ctx, tls_servername_cb); |
2226 | SSL_CTX_set_tlsext_servername_arg(ctx, cbinfo); | |
3f0945ff | 2227 | } |
f2de3a33 | 2228 | # ifndef DISABLE_OCSP |
f5d78688 JH |
2229 | else /* client */ |
2230 | if(ocsp_file) /* wanting stapling */ | |
2231 | { | |
2232 | if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new())) | |
2233 | { | |
2234 | DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n"); | |
2235 | return FAIL; | |
2236 | } | |
7006ee24 JH |
2237 | SSL_CTX_set_tlsext_status_cb(ctx, tls_client_stapling_cb); |
2238 | SSL_CTX_set_tlsext_status_arg(ctx, cbinfo); | |
f5d78688 JH |
2239 | } |
2240 | # endif | |
7be682ca | 2241 | #endif |
059ec3d9 | 2242 | |
e51c7be2 | 2243 | cbinfo->verify_cert_hostnames = NULL; |
e51c7be2 | 2244 | |
c8dfb21d | 2245 | #ifdef EXIM_HAVE_EPHEM_RSA_KEX |
059ec3d9 | 2246 | /* Set up the RSA callback */ |
7006ee24 | 2247 | SSL_CTX_set_tmp_rsa_callback(ctx, rsa_callback); |
c8dfb21d | 2248 | #endif |
059ec3d9 | 2249 | |
b10c87b3 JH |
2250 | /* Finally, set the session cache timeout, and we are done. |
2251 | The period appears to be also used for (server-generated) session tickets */ | |
059ec3d9 | 2252 | |
7006ee24 | 2253 | SSL_CTX_set_timeout(ctx, ssl_session_timeout); |
059ec3d9 | 2254 | DEBUG(D_tls) debug_printf("Initialized TLS\n"); |
7be682ca | 2255 | |
817d9f57 | 2256 | *cbp = cbinfo; |
7006ee24 | 2257 | *ctxp = ctx; |
7be682ca | 2258 | |
059ec3d9 PH |
2259 | return OK; |
2260 | } | |
2261 | ||
2262 | ||
2263 | ||
2264 | ||
2265 | /************************************************* | |
2266 | * Get name of cipher in use * | |
2267 | *************************************************/ | |
2268 | ||
817d9f57 | 2269 | /* |
059ec3d9 | 2270 | Argument: pointer to an SSL structure for the connection |
817d9f57 | 2271 | pointer to number of bits for cipher |
f1be21cf | 2272 | Returns: pointer to allocated string in perm-pool |
059ec3d9 PH |
2273 | */ |
2274 | ||
f1be21cf JH |
2275 | static uschar * |
2276 | construct_cipher_name(SSL * ssl, int * bits) | |
059ec3d9 | 2277 | { |
f1be21cf | 2278 | int pool = store_pool; |
7a8b9519 | 2279 | /* With OpenSSL 1.0.0a, 'c' needs to be const but the documentation doesn't |
57b3a7f5 PP |
2280 | yet reflect that. It should be a safe change anyway, even 0.9.8 versions have |
2281 | the accessor functions use const in the prototype. */ | |
059ec3d9 | 2282 | |
7a8b9519 JH |
2283 | const uschar * ver = CUS SSL_get_version(ssl); |
2284 | const SSL_CIPHER * c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); | |
f1be21cf | 2285 | uschar * s; |
059ec3d9 | 2286 | |
817d9f57 | 2287 | SSL_CIPHER_get_bits(c, bits); |
059ec3d9 | 2288 | |
f1be21cf JH |
2289 | store_pool = POOL_PERM; |
2290 | s = string_sprintf("%s:%s:%u", ver, SSL_CIPHER_get_name(c), *bits); | |
2291 | store_pool = pool; | |
2292 | DEBUG(D_tls) debug_printf("Cipher: %s\n", s); | |
2293 | return s; | |
2294 | } | |
2295 | ||
059ec3d9 | 2296 | |
f1be21cf JH |
2297 | /* Get IETF-standard name for ciphersuite. |
2298 | Argument: pointer to an SSL structure for the connection | |
2299 | Returns: pointer to string | |
2300 | */ | |
2301 | ||
2302 | static const uschar * | |
2303 | cipher_stdname_ssl(SSL * ssl) | |
2304 | { | |
2305 | #ifdef EXIM_HAVE_OPENSSL_CIPHER_STD_NAME | |
2306 | return CUS SSL_CIPHER_standard_name(SSL_get_current_cipher(ssl)); | |
2307 | #else | |
2308 | ushort id = 0xffff & SSL_CIPHER_get_id(SSL_get_current_cipher(ssl)); | |
2309 | return cipher_stdname(id >> 8, id & 0xff); | |
2310 | #endif | |
059ec3d9 PH |
2311 | } |
2312 | ||
2313 | ||
f69979cf | 2314 | static void |
70e384dd | 2315 | peer_cert(SSL * ssl, tls_support * tlsp, uschar * peerdn, unsigned siz) |
f69979cf JH |
2316 | { |
2317 | /*XXX we might consider a list-of-certs variable for the cert chain. | |
2318 | SSL_get_peer_cert_chain(SSL*). We'd need a new variable type and support | |
2319 | in list-handling functions, also consider the difference between the entire | |
2320 | chain and the elements sent by the peer. */ | |
2321 | ||
70e384dd JH |
2322 | tlsp->peerdn = NULL; |
2323 | ||
f69979cf JH |
2324 | /* Will have already noted peercert on a verify fail; possibly not the leaf */ |
2325 | if (!tlsp->peercert) | |
2326 | tlsp->peercert = SSL_get_peer_certificate(ssl); | |
2327 | /* Beware anonymous ciphers which lead to server_cert being NULL */ | |
2328 | if (tlsp->peercert) | |
70e384dd JH |
2329 | if (!X509_NAME_oneline(X509_get_subject_name(tlsp->peercert), CS peerdn, siz)) |
2330 | { DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); } | |
2331 | else | |
2332 | { | |
4a1bd6b9 JH |
2333 | int oldpool = store_pool; |
2334 | ||
2335 | peerdn[siz-1] = '\0'; /* paranoia */ | |
2336 | store_pool = POOL_PERM; | |
2337 | tlsp->peerdn = string_copy(peerdn); | |
2338 | store_pool = oldpool; | |
2339 | ||
2340 | /* We used to set CV in the cert-verify callbacks (either plain or dane) | |
2341 | but they don't get called on session-resumption. So use the official | |
2342 | interface, which uses the resumed value. Unfortunately this claims verified | |
2343 | when it actually failed but we're in try-verify mode, due to us wanting the | |
2344 | knowlege that it failed so needing to have the callback and forcing a | |
2345 | permissive return. If we don't force it, the TLS startup is failed. | |
f4e62a87 JH |
2346 | The extra bit of information is set in verify_override in the cb, stashed |
2347 | for resumption next to the TLS session, and used here. */ | |
4a1bd6b9 JH |
2348 | |
2349 | if (!tlsp->verify_override) | |
4ed67f68 JH |
2350 | tlsp->certificate_verified = |
2351 | #ifdef SUPPORT_DANE | |
2352 | tlsp->dane_verified || | |
2353 | #endif | |
2354 | SSL_get_verify_result(ssl) == X509_V_OK; | |
70e384dd | 2355 | } |
f69979cf JH |
2356 | } |
2357 | ||
2358 | ||
059ec3d9 PH |
2359 | |
2360 | ||
2361 | ||
2362 | /************************************************* | |
2363 | * Set up for verifying certificates * | |
2364 | *************************************************/ | |
2365 | ||
0e8aed8a | 2366 | #ifndef DISABLE_OCSP |
c3033f13 JH |
2367 | /* Load certs from file, return TRUE on success */ |
2368 | ||
2369 | static BOOL | |
2370 | chain_from_pem_file(const uschar * file, STACK_OF(X509) * verify_stack) | |
2371 | { | |
2372 | BIO * bp; | |
2373 | X509 * x; | |
2374 | ||
dec766a1 WB |
2375 | while (sk_X509_num(verify_stack) > 0) |
2376 | X509_free(sk_X509_pop(verify_stack)); | |
2377 | ||
c3033f13 JH |
2378 | if (!(bp = BIO_new_file(CS file, "r"))) return FALSE; |
2379 | while ((x = PEM_read_bio_X509(bp, NULL, 0, NULL))) | |
2380 | sk_X509_push(verify_stack, x); | |
2381 | BIO_free(bp); | |
2382 | return TRUE; | |
2383 | } | |
0e8aed8a | 2384 | #endif |
c3033f13 JH |
2385 | |
2386 | ||
2387 | ||
dec766a1 WB |
2388 | /* Called by both client and server startup; on the server possibly |
2389 | repeated after a Server Name Indication. | |
059ec3d9 PH |
2390 | |
2391 | Arguments: | |
7be682ca | 2392 | sctx SSL_CTX* to initialise |
059ec3d9 PH |
2393 | certs certs file or NULL |
2394 | crl CRL file or NULL | |
2395 | host NULL in a server; the remote host in a client | |
2396 | optional TRUE if called from a server for a host in tls_try_verify_hosts; | |
2397 | otherwise passed as FALSE | |
983207c1 | 2398 | cert_vfy_cb Callback function for certificate verification |
cf0c6164 | 2399 | errstr error string pointer |
059ec3d9 PH |
2400 | |
2401 | Returns: OK/DEFER/FAIL | |
2402 | */ | |
2403 | ||
2404 | static int | |
983207c1 | 2405 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
cf0c6164 | 2406 | int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr) |
059ec3d9 PH |
2407 | { |
2408 | uschar *expcerts, *expcrl; | |
2409 | ||
cf0c6164 | 2410 | if (!expand_check(certs, US"tls_verify_certificates", &expcerts, errstr)) |
059ec3d9 | 2411 | return DEFER; |
57cc2785 | 2412 | DEBUG(D_tls) debug_printf("tls_verify_certificates: %s\n", expcerts); |
059ec3d9 | 2413 | |
10a831a3 | 2414 | if (expcerts && *expcerts) |
059ec3d9 | 2415 | { |
10a831a3 JH |
2416 | /* Tell the library to use its compiled-in location for the system default |
2417 | CA bundle. Then add the ones specified in the config, if any. */ | |
cb1d7830 | 2418 | |
10a831a3 | 2419 | if (!SSL_CTX_set_default_verify_paths(sctx)) |
cf0c6164 | 2420 | return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL, errstr); |
10a831a3 JH |
2421 | |
2422 | if (Ustrcmp(expcerts, "system") != 0) | |
059ec3d9 | 2423 | { |
cb1d7830 JH |
2424 | struct stat statbuf; |
2425 | ||
cb1d7830 JH |
2426 | if (Ustat(expcerts, &statbuf) < 0) |
2427 | { | |
2428 | log_write(0, LOG_MAIN|LOG_PANIC, | |
2429 | "failed to stat %s for certificates", expcerts); | |
2430 | return DEFER; | |
2431 | } | |
059ec3d9 | 2432 | else |
059ec3d9 | 2433 | { |
cb1d7830 JH |
2434 | uschar *file, *dir; |
2435 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
2436 | { file = NULL; dir = expcerts; } | |
2437 | else | |
c3033f13 JH |
2438 | { |
2439 | file = expcerts; dir = NULL; | |
2440 | #ifndef DISABLE_OCSP | |
2441 | /* In the server if we will be offering an OCSP proof, load chain from | |
2442 | file for verifying the OCSP proof at load time. */ | |
2443 | ||
5b2fd993 JH |
2444 | /*XXX Glitch! The file here is tls_verify_certs: the chain for verifying the client cert. |
2445 | This is inconsistent with the need to verify the OCSP proof of the server cert. | |
2446 | */ | |
2447 | ||
c3033f13 JH |
2448 | if ( !host |
2449 | && statbuf.st_size > 0 | |
2450 | && server_static_cbinfo->u_ocsp.server.file | |
2451 | && !chain_from_pem_file(file, server_static_cbinfo->verify_stack) | |
2452 | ) | |
2453 | { | |
2454 | log_write(0, LOG_MAIN|LOG_PANIC, | |
57887ecc | 2455 | "failed to load cert chain from %s", file); |
c3033f13 JH |
2456 | return DEFER; |
2457 | } | |
2458 | #endif | |
2459 | } | |
cb1d7830 JH |
2460 | |
2461 | /* If a certificate file is empty, the next function fails with an | |
2462 | unhelpful error message. If we skip it, we get the correct behaviour (no | |
2463 | certificates are recognized, but the error message is still misleading (it | |
c3033f13 | 2464 | says no certificate was supplied). But this is better. */ |
cb1d7830 | 2465 | |
f2f2c91b JH |
2466 | if ( (!file || statbuf.st_size > 0) |
2467 | && !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) | |
cf0c6164 | 2468 | return tls_error(US"SSL_CTX_load_verify_locations", host, NULL, errstr); |
cb1d7830 JH |
2469 | |
2470 | /* Load the list of CAs for which we will accept certs, for sending | |
2471 | to the client. This is only for the one-file tls_verify_certificates | |
2472 | variant. | |
d7978c0f JH |
2473 | If a list isn't loaded into the server, but some verify locations are set, |
2474 | the server end appears to make a wildcard request for client certs. | |
10a831a3 | 2475 | Meanwhile, the client library as default behaviour *ignores* the list |
cb1d7830 JH |
2476 | we send over the wire - see man SSL_CTX_set_client_cert_cb. |
2477 | Because of this, and that the dir variant is likely only used for | |
d7978c0f JH |
2478 | the public-CA bundle (not for a private CA), not worth fixing. */ |
2479 | ||
f2f2c91b | 2480 | if (file) |
cb1d7830 | 2481 | { |
2009ecca | 2482 | STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file); |
dec766a1 WB |
2483 | |
2484 | SSL_CTX_set_client_CA_list(sctx, names); | |
f2f2c91b | 2485 | DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", |
cb1d7830 | 2486 | sk_X509_NAME_num(names)); |
cb1d7830 | 2487 | } |
059ec3d9 PH |
2488 | } |
2489 | } | |
2490 | ||
2491 | /* Handle a certificate revocation list. */ | |
2492 | ||
10a831a3 | 2493 | #if OPENSSL_VERSION_NUMBER > 0x00907000L |
059ec3d9 | 2494 | |
8b417f2c | 2495 | /* This bit of code is now the version supplied by Lars Mainka. (I have |
10a831a3 | 2496 | merely reformatted it into the Exim code style.) |
8b417f2c | 2497 | |
10a831a3 JH |
2498 | "From here I changed the code to add support for multiple crl's |
2499 | in pem format in one file or to support hashed directory entries in | |
2500 | pem format instead of a file. This method now uses the library function | |
2501 | X509_STORE_load_locations to add the CRL location to the SSL context. | |
2502 | OpenSSL will then handle the verify against CA certs and CRLs by | |
2503 | itself in the verify callback." */ | |
8b417f2c | 2504 | |
cf0c6164 | 2505 | if (!expand_check(crl, US"tls_crl", &expcrl, errstr)) return DEFER; |
10a831a3 | 2506 | if (expcrl && *expcrl) |
059ec3d9 | 2507 | { |
8b417f2c PH |
2508 | struct stat statbufcrl; |
2509 | if (Ustat(expcrl, &statbufcrl) < 0) | |
2510 | { | |
2511 | log_write(0, LOG_MAIN|LOG_PANIC, | |
2512 | "failed to stat %s for certificates revocation lists", expcrl); | |
2513 | return DEFER; | |
2514 | } | |
2515 | else | |
059ec3d9 | 2516 | { |
8b417f2c PH |
2517 | /* is it a file or directory? */ |
2518 | uschar *file, *dir; | |
7be682ca | 2519 | X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx); |
8b417f2c | 2520 | if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR) |
059ec3d9 | 2521 | { |
8b417f2c PH |
2522 | file = NULL; |
2523 | dir = expcrl; | |
2524 | DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir); | |
059ec3d9 PH |
2525 | } |
2526 | else | |
2527 | { | |
8b417f2c PH |
2528 | file = expcrl; |
2529 | dir = NULL; | |
2530 | DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); | |
059ec3d9 | 2531 | } |
8b417f2c | 2532 | if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) |
cf0c6164 | 2533 | return tls_error(US"X509_STORE_load_locations", host, NULL, errstr); |
8b417f2c PH |
2534 | |
2535 | /* setting the flags to check against the complete crl chain */ | |
2536 | ||
2537 | X509_STORE_set_flags(cvstore, | |
2538 | X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL); | |
059ec3d9 | 2539 | } |
059ec3d9 PH |
2540 | } |
2541 | ||
10a831a3 | 2542 | #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ |
059ec3d9 PH |
2543 | |
2544 | /* If verification is optional, don't fail if no certificate */ | |
2545 | ||
7be682ca | 2546 | SSL_CTX_set_verify(sctx, |
5a2a0989 | 2547 | SSL_VERIFY_PEER | (optional ? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT), |
983207c1 | 2548 | cert_vfy_cb); |
059ec3d9 PH |
2549 | } |
2550 | ||
2551 | return OK; | |
2552 | } | |
2553 | ||
2554 | ||
2555 | ||
2556 | /************************************************* | |
2557 | * Start a TLS session in a server * | |
2558 | *************************************************/ | |
2559 | ||
2560 | /* This is called when Exim is running as a server, after having received | |
2561 | the STARTTLS command. It must respond to that command, and then negotiate | |
2562 | a TLS session. | |
2563 | ||
2564 | Arguments: | |
2565 | require_ciphers allowed ciphers | |
cf0c6164 | 2566 | errstr pointer to error message |
059ec3d9 PH |
2567 | |
2568 | Returns: OK on success | |
2569 | DEFER for errors before the start of the negotiation | |
4c04137d | 2570 | FAIL for errors during the negotiation; the server can't |
059ec3d9 PH |
2571 | continue running. |
2572 | */ | |
2573 | ||
2574 | int | |
cf0c6164 | 2575 | tls_server_start(const uschar * require_ciphers, uschar ** errstr) |
059ec3d9 PH |
2576 | { |
2577 | int rc; | |
cf0c6164 JH |
2578 | uschar * expciphers; |
2579 | tls_ext_ctx_cb * cbinfo; | |
f69979cf | 2580 | static uschar peerdn[256]; |
059ec3d9 PH |
2581 | |
2582 | /* Check for previous activation */ | |
2583 | ||
74f1a423 | 2584 | if (tls_in.active.sock >= 0) |
059ec3d9 | 2585 | { |
cf0c6164 | 2586 | tls_error(US"STARTTLS received after TLS started", NULL, US"", errstr); |
925ac8e4 | 2587 | smtp_printf("554 Already in TLS\r\n", FALSE); |
059ec3d9 PH |
2588 | return FAIL; |
2589 | } | |
2590 | ||
2591 | /* Initialize the SSL library. If it fails, it will already have logged | |
2592 | the error. */ | |
2593 | ||
817d9f57 | 2594 | rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey, |
f2de3a33 | 2595 | #ifndef DISABLE_OCSP |
5b2fd993 | 2596 | tls_ocsp_file, |
3f7eeb86 | 2597 | #endif |
b10c87b3 | 2598 | NULL, &server_static_cbinfo, &tls_in, errstr); |
059ec3d9 | 2599 | if (rc != OK) return rc; |
817d9f57 | 2600 | cbinfo = server_static_cbinfo; |
059ec3d9 | 2601 | |
cf0c6164 | 2602 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers, errstr)) |
059ec3d9 PH |
2603 | return FAIL; |
2604 | ||
2605 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
17c76198 PP |
2606 | were historically separated by underscores. So that I can use either form in my |
2607 | tests, and also for general convenience, we turn underscores into hyphens here. | |
0c3807a8 JH |
2608 | |
2609 | XXX SSL_CTX_set_cipher_list() is replaced by SSL_CTX_set_ciphersuites() | |
2610 | for TLS 1.3 . Since we do not call it at present we get the default list: | |
2611 | TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256 | |
17c76198 | 2612 | */ |
059ec3d9 | 2613 | |
c3033f13 | 2614 | if (expciphers) |
059ec3d9 | 2615 | { |
b10c87b3 | 2616 | for (uschar * s = expciphers; *s; s++ ) if (*s == '_') *s = '-'; |
059ec3d9 | 2617 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); |
817d9f57 | 2618 | if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) |
cf0c6164 | 2619 | return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL, errstr); |
7be682ca | 2620 | cbinfo->server_cipher_list = expciphers; |
059ec3d9 PH |
2621 | } |
2622 | ||
2623 | /* If this is a host for which certificate verification is mandatory or | |
2624 | optional, set up appropriately. */ | |
2625 | ||
817d9f57 | 2626 | tls_in.certificate_verified = FALSE; |
c0635b6d | 2627 | #ifdef SUPPORT_DANE |
53a7196b JH |
2628 | tls_in.dane_verified = FALSE; |
2629 | #endif | |
a2ff477a | 2630 | server_verify_callback_called = FALSE; |
059ec3d9 PH |
2631 | |
2632 | if (verify_check_host(&tls_verify_hosts) == OK) | |
2633 | { | |
983207c1 | 2634 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
afdb5e9c | 2635 | FALSE, verify_callback_server, errstr); |
059ec3d9 | 2636 | if (rc != OK) return rc; |
a2ff477a | 2637 | server_verify_optional = FALSE; |
059ec3d9 PH |
2638 | } |
2639 | else if (verify_check_host(&tls_try_verify_hosts) == OK) | |
2640 | { | |
983207c1 | 2641 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
afdb5e9c | 2642 | TRUE, verify_callback_server, errstr); |
059ec3d9 | 2643 | if (rc != OK) return rc; |
a2ff477a | 2644 | server_verify_optional = TRUE; |
059ec3d9 PH |
2645 | } |
2646 | ||
b10c87b3 JH |
2647 | #ifdef EXPERIMENTAL_TLS_RESUME |
2648 | SSL_CTX_set_tlsext_ticket_key_cb(server_ctx, ticket_key_callback); | |
2649 | /* despite working, appears to always return failure, so ignoring */ | |
2650 | #endif | |
2651 | #ifdef OPENSSL_HAVE_NUM_TICKETS | |
2652 | # ifdef EXPERIMENTAL_TLS_RESUME | |
2653 | SSL_CTX_set_num_tickets(server_ctx, tls_in.host_resumable ? 1 : 0); | |
2654 | # else | |
2655 | SSL_CTX_set_num_tickets(server_ctx, 0); /* send no TLS1.3 stateful-tickets */ | |
2656 | # endif | |
2657 | #endif | |
2658 | ||
2659 | ||
059ec3d9 PH |
2660 | /* Prepare for new connection */ |
2661 | ||
cf0c6164 JH |
2662 | if (!(server_ssl = SSL_new(server_ctx))) |
2663 | return tls_error(US"SSL_new", NULL, NULL, errstr); | |
da3ad30d PP |
2664 | |
2665 | /* Warning: we used to SSL_clear(ssl) here, it was removed. | |
2666 | * | |
2667 | * With the SSL_clear(), we get strange interoperability bugs with | |
2668 | * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in | |
2669 | * OpenSSL itself, as a clear should not lead to inability to follow protocols. | |
2670 | * | |
2671 | * The SSL_clear() call is to let an existing SSL* be reused, typically after | |
2672 | * session shutdown. In this case, we have a brand new object and there's no | |
2673 | * obvious reason to immediately clear it. I'm guessing that this was | |
2674 | * originally added because of incomplete initialisation which the clear fixed, | |
2675 | * in some historic release. | |
2676 | */ | |
059ec3d9 PH |
2677 | |
2678 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
2679 | on connection, where outputting anything now upsets the clients and tends to | |
2680 | make them disconnect. We need to have an explicit fflush() here, to force out | |
2681 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
2682 | mode, the fflush() happens when smtp_getc() is called. */ | |
2683 | ||
817d9f57 JH |
2684 | SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx)); |
2685 | if (!tls_in.on_connect) | |
059ec3d9 | 2686 | { |
925ac8e4 | 2687 | smtp_printf("220 TLS go ahead\r\n", FALSE); |
059ec3d9 PH |
2688 | fflush(smtp_out); |
2689 | } | |
2690 | ||
2691 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
2692 | that the OpenSSL library doesn't. */ | |
2693 | ||
817d9f57 JH |
2694 | SSL_set_wfd(server_ssl, fileno(smtp_out)); |
2695 | SSL_set_rfd(server_ssl, fileno(smtp_in)); | |
2696 | SSL_set_accept_state(server_ssl); | |
059ec3d9 PH |
2697 | |
2698 | DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); | |
2699 | ||
2700 | sigalrm_seen = FALSE; | |
c2a1bba0 | 2701 | if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); |
817d9f57 | 2702 | rc = SSL_accept(server_ssl); |
c2a1bba0 | 2703 | ALARM_CLR(0); |
059ec3d9 PH |
2704 | |
2705 | if (rc <= 0) | |
2706 | { | |
c31e16a5 JH |
2707 | int error = SSL_get_error(server_ssl, rc); |
2708 | switch(error) | |
2709 | { | |
2710 | case SSL_ERROR_NONE: | |
2711 | break; | |
2712 | ||
2713 | case SSL_ERROR_ZERO_RETURN: | |
2714 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2715 | (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr); | |
2716 | ||
2717 | if (SSL_get_shutdown(server_ssl) == SSL_RECEIVED_SHUTDOWN) | |
2718 | SSL_shutdown(server_ssl); | |
2719 | ||
2720 | tls_close(NULL, TLS_NO_SHUTDOWN); | |
2721 | return FAIL; | |
2722 | ||
2723 | /* Handle genuine errors */ | |
2724 | case SSL_ERROR_SSL: | |
fa9e4a1d JH |
2725 | { |
2726 | uschar * s = US"SSL_accept"; | |
4ed67f68 | 2727 | unsigned long e = ERR_peek_error(); |
fa9e4a1d JH |
2728 | if (ERR_GET_REASON(e) == SSL_R_WRONG_VERSION_NUMBER) |
2729 | s = string_sprintf("%s (%s)", s, SSL_get_version(server_ssl)); | |
2730 | (void) tls_error(s, NULL, sigalrm_seen ? US"timed out" : NULL, errstr); | |
c31e16a5 | 2731 | return FAIL; |
fa9e4a1d | 2732 | } |
c31e16a5 JH |
2733 | |
2734 | default: | |
2735 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
2736 | if (error == SSL_ERROR_SYSCALL) | |
2737 | { | |
2738 | if (!errno) | |
2739 | { | |
2740 | *errstr = US"SSL_accept: TCP connection closed by peer"; | |
2741 | return FAIL; | |
2742 | } | |
2743 | DEBUG(D_tls) debug_printf(" - syscall %s\n", strerror(errno)); | |
2744 | } | |
2745 | (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr); | |
2746 | return FAIL; | |
2747 | } | |
059ec3d9 PH |
2748 | } |
2749 | ||
2750 | DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); | |
25fa0868 | 2751 | ERR_clear_error(); /* Even success can leave errors in the stack. Seen with |
b10c87b3 JH |
2752 | anon-authentication ciphersuite negotiated. */ |
2753 | ||
2754 | #ifdef EXPERIMENTAL_TLS_RESUME | |
2755 | if (SSL_session_reused(server_ssl)) | |
2756 | { | |
2757 | tls_in.resumption |= RESUME_USED; | |
2758 | DEBUG(D_tls) debug_printf("Session reused\n"); | |
2759 | } | |
2760 | #endif | |
059ec3d9 PH |
2761 | |
2762 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
2763 | and initialize things. */ | |
2764 | ||
f69979cf JH |
2765 | peer_cert(server_ssl, &tls_in, peerdn, sizeof(peerdn)); |
2766 | ||
f1be21cf JH |
2767 | tls_in.cipher = construct_cipher_name(server_ssl, &tls_in.bits); |
2768 | tls_in.cipher_stdname = cipher_stdname_ssl(server_ssl); | |
2769 | ||
059ec3d9 PH |
2770 | DEBUG(D_tls) |
2771 | { | |
2772 | uschar buf[2048]; | |
f1be21cf | 2773 | if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf))) |
059ec3d9 | 2774 | debug_printf("Shared ciphers: %s\n", buf); |
f20cfa4a JH |
2775 | |
2776 | #ifdef EXIM_HAVE_OPENSSL_KEYLOG | |
2777 | { | |
10ed27e0 | 2778 | BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE); |
f20cfa4a | 2779 | SSL_SESSION_print_keylog(bp, SSL_get_session(server_ssl)); |
f20cfa4a JH |
2780 | BIO_free(bp); |
2781 | } | |
2782 | #endif | |
b10c87b3 JH |
2783 | |
2784 | #ifdef EXIM_HAVE_SESSION_TICKET | |
2785 | { | |
2786 | SSL_SESSION * ss = SSL_get_session(server_ssl); | |
40618fb6 | 2787 | if (SSL_SESSION_has_ticket(ss)) /* 1.1.0 */ |
b10c87b3 JH |
2788 | debug_printf("The session has a ticket, life %lu seconds\n", |
2789 | SSL_SESSION_get_ticket_lifetime_hint(ss)); | |
2790 | } | |
2791 | #endif | |
059ec3d9 PH |
2792 | } |
2793 | ||
9d1c15ef JH |
2794 | /* Record the certificate we presented */ |
2795 | { | |
2796 | X509 * crt = SSL_get_certificate(server_ssl); | |
2797 | tls_in.ourcert = crt ? X509_dup(crt) : NULL; | |
2798 | } | |
059ec3d9 | 2799 | |
817d9f57 JH |
2800 | /* Only used by the server-side tls (tls_in), including tls_getc. |
2801 | Client-side (tls_out) reads (seem to?) go via | |
2802 | smtp_read_response()/ip_recv(). | |
2803 | Hence no need to duplicate for _in and _out. | |
2804 | */ | |
b808677c | 2805 | if (!ssl_xfer_buffer) ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
059ec3d9 | 2806 | ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; |
8b77d27a | 2807 | ssl_xfer_eof = ssl_xfer_error = FALSE; |
059ec3d9 PH |
2808 | |
2809 | receive_getc = tls_getc; | |
0d81dabc | 2810 | receive_getbuf = tls_getbuf; |
584e96c6 | 2811 | receive_get_cache = tls_get_cache; |
059ec3d9 PH |
2812 | receive_ungetc = tls_ungetc; |
2813 | receive_feof = tls_feof; | |
2814 | receive_ferror = tls_ferror; | |
58eb016e | 2815 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 2816 | |
74f1a423 JH |
2817 | tls_in.active.sock = fileno(smtp_out); |
2818 | tls_in.active.tls_ctx = NULL; /* not using explicit ctx for server-side */ | |
059ec3d9 PH |
2819 | return OK; |
2820 | } | |
2821 | ||
2822 | ||
2823 | ||
2824 | ||
043b1248 JH |
2825 | static int |
2826 | tls_client_basic_ctx_init(SSL_CTX * ctx, | |
cf0c6164 JH |
2827 | host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo, |
2828 | uschar ** errstr) | |
043b1248 JH |
2829 | { |
2830 | int rc; | |
94431adb | 2831 | /* stick to the old behaviour for compatibility if tls_verify_certificates is |
043b1248 JH |
2832 | set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only |
2833 | the specified host patterns if one of them is defined */ | |
2834 | ||
610ff438 JH |
2835 | if ( ( !ob->tls_verify_hosts |
2836 | && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) | |
2837 | ) | |
3c07dd2d | 2838 | || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK |
aa2a70ba | 2839 | ) |
043b1248 | 2840 | client_verify_optional = FALSE; |
3c07dd2d | 2841 | else if (verify_check_given_host(CUSS &ob->tls_try_verify_hosts, host) == OK) |
aa2a70ba JH |
2842 | client_verify_optional = TRUE; |
2843 | else | |
2844 | return OK; | |
2845 | ||
2846 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
cf0c6164 JH |
2847 | ob->tls_crl, host, client_verify_optional, verify_callback_client, |
2848 | errstr)) != OK) | |
aa2a70ba | 2849 | return rc; |
043b1248 | 2850 | |
3c07dd2d | 2851 | if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK) |
043b1248 | 2852 | { |
4af0d74a | 2853 | cbinfo->verify_cert_hostnames = |
8c5d388a | 2854 | #ifdef SUPPORT_I18N |
4af0d74a JH |
2855 | string_domain_utf8_to_alabel(host->name, NULL); |
2856 | #else | |
2857 | host->name; | |
2858 | #endif | |
aa2a70ba JH |
2859 | DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", |
2860 | cbinfo->verify_cert_hostnames); | |
043b1248 | 2861 | } |
043b1248 JH |
2862 | return OK; |
2863 | } | |
059ec3d9 | 2864 | |
fde080a4 | 2865 | |
c0635b6d | 2866 | #ifdef SUPPORT_DANE |
fde080a4 | 2867 | static int |
cf0c6164 | 2868 | dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa, uschar ** errstr) |
fde080a4 | 2869 | { |
fde080a4 JH |
2870 | dns_scan dnss; |
2871 | const char * hostnames[2] = { CS host->name, NULL }; | |
2872 | int found = 0; | |
2873 | ||
2874 | if (DANESSL_init(ssl, NULL, hostnames) != 1) | |
cf0c6164 | 2875 | return tls_error(US"hostnames load", host, NULL, errstr); |
fde080a4 | 2876 | |
d7978c0f | 2877 | for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; |
fde080a4 | 2878 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) |
1b76ad22 | 2879 | ) if (rr->type == T_TLSA && rr->size > 3) |
fde080a4 | 2880 | { |
c3033f13 | 2881 | const uschar * p = rr->data; |
fde080a4 JH |
2882 | uint8_t usage, selector, mtype; |
2883 | const char * mdname; | |
2884 | ||
fde080a4 | 2885 | usage = *p++; |
133d2546 JH |
2886 | |
2887 | /* Only DANE-TA(2) and DANE-EE(3) are supported */ | |
2888 | if (usage != 2 && usage != 3) continue; | |
2889 | ||
fde080a4 JH |
2890 | selector = *p++; |
2891 | mtype = *p++; | |
2892 | ||
2893 | switch (mtype) | |
2894 | { | |
133d2546 JH |
2895 | default: continue; /* Only match-types 0, 1, 2 are supported */ |
2896 | case 0: mdname = NULL; break; | |
2897 | case 1: mdname = "sha256"; break; | |
2898 | case 2: mdname = "sha512"; break; | |
fde080a4 JH |
2899 | } |
2900 | ||
133d2546 | 2901 | found++; |
fde080a4 JH |
2902 | switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3)) |
2903 | { | |
2904 | default: | |
cf0c6164 | 2905 | return tls_error(US"tlsa load", host, NULL, errstr); |
c035b645 | 2906 | case 0: /* action not taken */ |
fde080a4 JH |
2907 | case 1: break; |
2908 | } | |
594706ea JH |
2909 | |
2910 | tls_out.tlsa_usage |= 1<<usage; | |
fde080a4 JH |
2911 | } |
2912 | ||
2913 | if (found) | |
2914 | return OK; | |
2915 | ||
133d2546 | 2916 | log_write(0, LOG_MAIN, "DANE error: No usable TLSA records"); |
6ebd79ec | 2917 | return DEFER; |
fde080a4 | 2918 | } |
c0635b6d | 2919 | #endif /*SUPPORT_DANE*/ |
fde080a4 JH |
2920 | |
2921 | ||
2922 | ||
b10c87b3 JH |
2923 | #ifdef EXPERIMENTAL_TLS_RESUME |
2924 | /* On the client, get any stashed session for the given IP from hints db | |
2925 | and apply it to the ssl-connection for attempted resumption. */ | |
2926 | ||
2927 | static void | |
2928 | tls_retrieve_session(tls_support * tlsp, SSL * ssl, const uschar * key) | |
2929 | { | |
2930 | tlsp->resumption |= RESUME_SUPPORTED; | |
2931 | if (tlsp->host_resumable) | |
2932 | { | |
2933 | dbdata_tls_session * dt; | |
2934 | int len; | |
2935 | open_db dbblock, * dbm_file; | |
2936 | ||
2937 | tlsp->resumption |= RESUME_CLIENT_REQUESTED; | |
2938 | DEBUG(D_tls) debug_printf("checking for resumable session for %s\n", key); | |
2939 | if ((dbm_file = dbfn_open(US"tls", O_RDONLY, &dbblock, FALSE, FALSE))) | |
2940 | { | |
2941 | /* key for the db is the IP */ | |
2942 | if ((dt = dbfn_read_with_length(dbm_file, key, &len))) | |
2943 | { | |
2944 | SSL_SESSION * ss = NULL; | |
2945 | const uschar * sess_asn1 = dt->session; | |
2946 | ||
2947 | len -= sizeof(dbdata_tls_session); | |
2948 | if (!(d2i_SSL_SESSION(&ss, &sess_asn1, (long)len))) | |
2949 | { | |
2950 | DEBUG(D_tls) | |
2951 | { | |
2952 | ERR_error_string_n(ERR_get_error(), | |
2953 | ssl_errstring, sizeof(ssl_errstring)); | |
2954 | debug_printf("decoding session: %s\n", ssl_errstring); | |
2955 | } | |
2956 | } | |
a775dd1d | 2957 | #ifdef EXIM_HAVE_SESSION_TICKET |
4f1d23a1 JH |
2958 | else if ( SSL_SESSION_get_ticket_lifetime_hint(ss) + dt->time_stamp |
2959 | < time(NULL)) | |
2960 | { | |
2961 | DEBUG(D_tls) debug_printf("session expired\n"); | |
2962 | dbfn_delete(dbm_file, key); | |
2963 | } | |
a775dd1d | 2964 | #endif |
b10c87b3 JH |
2965 | else if (!SSL_set_session(ssl, ss)) |
2966 | { | |
2967 | DEBUG(D_tls) | |
2968 | { | |
2969 | ERR_error_string_n(ERR_get_error(), | |
2970 | ssl_errstring, sizeof(ssl_errstring)); | |
2971 | debug_printf("applying session to ssl: %s\n", ssl_errstring); | |
2972 | } | |
2973 | } | |
2974 | else | |
2975 | { | |
2976 | DEBUG(D_tls) debug_printf("good session\n"); | |
2977 | tlsp->resumption |= RESUME_CLIENT_SUGGESTED; | |
f4e62a87 | 2978 | tlsp->verify_override = dt->verify_override; |
c82de233 | 2979 | tlsp->ocsp = dt->ocsp; |
b10c87b3 JH |
2980 | } |
2981 | } | |
2982 | else | |
2983 | DEBUG(D_tls) debug_printf("no session record\n"); | |
2984 | dbfn_close(dbm_file); | |
2985 | } | |
2986 | } | |
2987 | } | |
2988 | ||
2989 | ||
2990 | /* On the client, save the session for later resumption */ | |
2991 | ||
2992 | static int | |
2993 | tls_save_session_cb(SSL * ssl, SSL_SESSION * ss) | |
2994 | { | |
2995 | tls_ext_ctx_cb * cbinfo = SSL_get_ex_data(ssl, tls_exdata_idx); | |
2996 | tls_support * tlsp; | |
2997 | ||
2998 | DEBUG(D_tls) debug_printf("tls_save_session_cb\n"); | |
2999 | ||
3000 | if (!cbinfo || !(tlsp = cbinfo->tlsp)->host_resumable) return 0; | |
3001 | ||
40618fb6 JH |
3002 | # ifdef OPENSSL_HAVE_NUM_TICKETS |
3003 | if (SSL_SESSION_is_resumable(ss)) /* 1.1.1 */ | |
3004 | # endif | |
b10c87b3 JH |
3005 | { |
3006 | int len = i2d_SSL_SESSION(ss, NULL); | |
3007 | int dlen = sizeof(dbdata_tls_session) + len; | |
f3ebb786 | 3008 | dbdata_tls_session * dt = store_get(dlen, TRUE); |
b10c87b3 JH |
3009 | uschar * s = dt->session; |
3010 | open_db dbblock, * dbm_file; | |
3011 | ||
3012 | DEBUG(D_tls) debug_printf("session is resumable\n"); | |
3013 | tlsp->resumption |= RESUME_SERVER_TICKET; /* server gave us a ticket */ | |
3014 | ||
f4e62a87 | 3015 | dt->verify_override = tlsp->verify_override; |
c82de233 | 3016 | dt->ocsp = tlsp->ocsp; |
f4e62a87 | 3017 | (void) i2d_SSL_SESSION(ss, &s); /* s gets bumped to end */ |
b10c87b3 JH |
3018 | |
3019 | if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE))) | |
3020 | { | |
3021 | const uschar * key = cbinfo->host->address; | |
3022 | dbfn_delete(dbm_file, key); | |
3023 | dbfn_write(dbm_file, key, dt, dlen); | |
3024 | dbfn_close(dbm_file); | |
3025 | DEBUG(D_tls) debug_printf("wrote session (len %u) to db\n", | |
3026 | (unsigned)dlen); | |
3027 | } | |
3028 | } | |
b10c87b3 JH |
3029 | return 1; |
3030 | } | |
3031 | ||
3032 | ||
3033 | static void | |
3034 | tls_client_ctx_resume_prehandshake( | |
3035 | exim_openssl_client_tls_ctx * exim_client_ctx, tls_support * tlsp, | |
3036 | smtp_transport_options_block * ob, host_item * host) | |
3037 | { | |
3038 | /* Should the client request a session resumption ticket? */ | |
3039 | if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, host) == OK) | |
3040 | { | |
3041 | tlsp->host_resumable = TRUE; | |
3042 | ||
3043 | SSL_CTX_set_session_cache_mode(exim_client_ctx->ctx, | |
3044 | SSL_SESS_CACHE_CLIENT | |
3045 | | SSL_SESS_CACHE_NO_INTERNAL | SSL_SESS_CACHE_NO_AUTO_CLEAR); | |
3046 | SSL_CTX_sess_set_new_cb(exim_client_ctx->ctx, tls_save_session_cb); | |
3047 | } | |
3048 | } | |
3049 | ||
3050 | static BOOL | |
3051 | tls_client_ssl_resume_prehandshake(SSL * ssl, tls_support * tlsp, | |
3052 | host_item * host, uschar ** errstr) | |
3053 | { | |
3054 | if (tlsp->host_resumable) | |
3055 | { | |
3056 | DEBUG(D_tls) | |
3057 | debug_printf("tls_resumption_hosts overrides openssl_options, enabling tickets\n"); | |
3058 | SSL_clear_options(ssl, SSL_OP_NO_TICKET); | |
3059 | ||
3060 | tls_exdata_idx = SSL_get_ex_new_index(0, 0, 0, 0, 0); | |
3061 | if (!SSL_set_ex_data(ssl, tls_exdata_idx, client_static_cbinfo)) | |
3062 | { | |
3063 | tls_error(US"set ex_data", host, NULL, errstr); | |
3064 | return FALSE; | |
3065 | } | |
3066 | debug_printf("tls_exdata_idx %d cbinfo %p\n", tls_exdata_idx, client_static_cbinfo); | |
3067 | } | |
3068 | ||
3069 | tlsp->resumption = RESUME_SUPPORTED; | |
3070 | /* Pick up a previous session, saved on an old ticket */ | |
3071 | tls_retrieve_session(tlsp, ssl, host->address); | |
3072 | return TRUE; | |
3073 | } | |
3074 | ||
3075 | static void | |
3076 | tls_client_resume_posthandshake(exim_openssl_client_tls_ctx * exim_client_ctx, | |
3077 | tls_support * tlsp) | |
3078 | { | |
3079 | if (SSL_session_reused(exim_client_ctx->ssl)) | |
3080 | { | |
3081 | DEBUG(D_tls) debug_printf("The session was reused\n"); | |
3082 | tlsp->resumption |= RESUME_USED; | |
3083 | } | |
3084 | } | |
3085 | #endif /* EXPERIMENTAL_TLS_RESUME */ | |
3086 | ||
3087 | ||
059ec3d9 PH |
3088 | /************************************************* |
3089 | * Start a TLS session in a client * | |
3090 | *************************************************/ | |
3091 | ||
3092 | /* Called from the smtp transport after STARTTLS has been accepted. | |
3093 | ||
c05bdbd6 JH |
3094 | Arguments: |
3095 | cctx connection context | |
3096 | conn_args connection details | |
3097 | cookie datum for randomness; can be NULL | |
3098 | tlsp record details of TLS channel configuration here; must be non-NULL | |
3099 | errstr error string pointer | |
3100 | ||
3101 | Returns: TRUE for success with TLS session context set in connection context, | |
3102 | FALSE on error | |
059ec3d9 PH |
3103 | */ |
3104 | ||
c05bdbd6 JH |
3105 | BOOL |
3106 | tls_client_start(client_conn_ctx * cctx, smtp_connect_args * conn_args, | |
3107 | void * cookie, tls_support * tlsp, uschar ** errstr) | |
059ec3d9 | 3108 | { |
c05bdbd6 JH |
3109 | host_item * host = conn_args->host; /* for msgs and option-tests */ |
3110 | transport_instance * tb = conn_args->tblock; /* always smtp or NULL */ | |
afdb5e9c JH |
3111 | smtp_transport_options_block * ob = tb |
3112 | ? (smtp_transport_options_block *)tb->options_block | |
3113 | : &smtp_transport_option_defaults; | |
74f1a423 | 3114 | exim_openssl_client_tls_ctx * exim_client_ctx; |
868f5672 | 3115 | uschar * expciphers; |
059ec3d9 | 3116 | int rc; |
c05bdbd6 | 3117 | static uschar peerdn[256]; |
043b1248 JH |
3118 | |
3119 | #ifndef DISABLE_OCSP | |
043b1248 | 3120 | BOOL request_ocsp = FALSE; |
6634ac8d | 3121 | BOOL require_ocsp = FALSE; |
043b1248 | 3122 | #endif |
043b1248 | 3123 | |
74f1a423 JH |
3124 | rc = store_pool; |
3125 | store_pool = POOL_PERM; | |
f3ebb786 | 3126 | exim_client_ctx = store_get(sizeof(exim_openssl_client_tls_ctx), FALSE); |
c09dbcfb | 3127 | exim_client_ctx->corked = NULL; |
74f1a423 JH |
3128 | store_pool = rc; |
3129 | ||
c0635b6d | 3130 | #ifdef SUPPORT_DANE |
74f1a423 | 3131 | tlsp->tlsa_usage = 0; |
043b1248 JH |
3132 | #endif |
3133 | ||
f2de3a33 | 3134 | #ifndef DISABLE_OCSP |
043b1248 | 3135 | { |
c0635b6d | 3136 | # ifdef SUPPORT_DANE |
c05bdbd6 | 3137 | if ( conn_args->dane |
4f59c424 JH |
3138 | && ob->hosts_request_ocsp[0] == '*' |
3139 | && ob->hosts_request_ocsp[1] == '\0' | |
3140 | ) | |
3141 | { | |
3142 | /* Unchanged from default. Use a safer one under DANE */ | |
3143 | request_ocsp = TRUE; | |
3144 | ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} " | |
3145 | " {= {4}{$tls_out_tlsa_usage}} } " | |
3146 | " {*}{}}"; | |
3147 | } | |
3148 | # endif | |
3149 | ||
5130845b | 3150 | if ((require_ocsp = |
3c07dd2d | 3151 | verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK)) |
fca41d5a JH |
3152 | request_ocsp = TRUE; |
3153 | else | |
c0635b6d | 3154 | # ifdef SUPPORT_DANE |
4f59c424 | 3155 | if (!request_ocsp) |
fca41d5a | 3156 | # endif |
5130845b | 3157 | request_ocsp = |
3c07dd2d | 3158 | verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK; |
043b1248 | 3159 | } |
f5d78688 | 3160 | #endif |
059ec3d9 | 3161 | |
74f1a423 | 3162 | rc = tls_init(&exim_client_ctx->ctx, host, NULL, |
65867078 | 3163 | ob->tls_certificate, ob->tls_privatekey, |
f2de3a33 | 3164 | #ifndef DISABLE_OCSP |
44662487 | 3165 | (void *)(long)request_ocsp, |
3f7eeb86 | 3166 | #endif |
b10c87b3 | 3167 | cookie, &client_static_cbinfo, tlsp, errstr); |
c05bdbd6 | 3168 | if (rc != OK) return FALSE; |
059ec3d9 | 3169 | |
74f1a423 | 3170 | tlsp->certificate_verified = FALSE; |
a2ff477a | 3171 | client_verify_callback_called = FALSE; |
059ec3d9 | 3172 | |
5ec37a55 PP |
3173 | expciphers = NULL; |
3174 | #ifdef SUPPORT_DANE | |
c05bdbd6 | 3175 | if (conn_args->dane) |
5ec37a55 PP |
3176 | { |
3177 | /* We fall back to tls_require_ciphers if unset, empty or forced failure, but | |
3178 | other failures should be treated as problems. */ | |
3179 | if (ob->dane_require_tls_ciphers && | |
3180 | !expand_check(ob->dane_require_tls_ciphers, US"dane_require_tls_ciphers", | |
3181 | &expciphers, errstr)) | |
c05bdbd6 | 3182 | return FALSE; |
5ec37a55 PP |
3183 | if (expciphers && *expciphers == '\0') |
3184 | expciphers = NULL; | |
3185 | } | |
3186 | #endif | |
3187 | if (!expciphers && | |
3188 | !expand_check(ob->tls_require_ciphers, US"tls_require_ciphers", | |
3189 | &expciphers, errstr)) | |
c05bdbd6 | 3190 | return FALSE; |
059ec3d9 PH |
3191 | |
3192 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
3193 | are separated by underscores. So that I can use either form in my tests, and | |
3194 | also for general convenience, we turn underscores into hyphens here. */ | |
3195 | ||
cf0c6164 | 3196 | if (expciphers) |
059ec3d9 PH |
3197 | { |
3198 | uschar *s = expciphers; | |
cf0c6164 | 3199 | while (*s) { if (*s == '_') *s = '-'; s++; } |
059ec3d9 | 3200 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); |
74f1a423 JH |
3201 | if (!SSL_CTX_set_cipher_list(exim_client_ctx->ctx, CS expciphers)) |
3202 | { | |
3203 | tls_error(US"SSL_CTX_set_cipher_list", host, NULL, errstr); | |
c05bdbd6 | 3204 | return FALSE; |
74f1a423 | 3205 | } |
059ec3d9 PH |
3206 | } |
3207 | ||
c0635b6d | 3208 | #ifdef SUPPORT_DANE |
c05bdbd6 | 3209 | if (conn_args->dane) |
a63be306 | 3210 | { |
74f1a423 | 3211 | SSL_CTX_set_verify(exim_client_ctx->ctx, |
02af313d JH |
3212 | SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, |
3213 | verify_callback_client_dane); | |
e5cccda9 | 3214 | |
043b1248 | 3215 | if (!DANESSL_library_init()) |
74f1a423 JH |
3216 | { |
3217 | tls_error(US"library init", host, NULL, errstr); | |
c05bdbd6 | 3218 | return FALSE; |
74f1a423 JH |
3219 | } |
3220 | if (DANESSL_CTX_init(exim_client_ctx->ctx) <= 0) | |
3221 | { | |
3222 | tls_error(US"context init", host, NULL, errstr); | |
c05bdbd6 | 3223 | return FALSE; |
74f1a423 | 3224 | } |
043b1248 JH |
3225 | } |
3226 | else | |
e51c7be2 | 3227 | |
043b1248 JH |
3228 | #endif |
3229 | ||
74f1a423 JH |
3230 | if (tls_client_basic_ctx_init(exim_client_ctx->ctx, host, ob, |
3231 | client_static_cbinfo, errstr) != OK) | |
c05bdbd6 | 3232 | return FALSE; |
059ec3d9 | 3233 | |
b10c87b3 JH |
3234 | #ifdef EXPERIMENTAL_TLS_RESUME |
3235 | tls_client_ctx_resume_prehandshake(exim_client_ctx, tlsp, ob, host); | |
3236 | #endif | |
3237 | ||
3238 | ||
74f1a423 JH |
3239 | if (!(exim_client_ctx->ssl = SSL_new(exim_client_ctx->ctx))) |
3240 | { | |
3241 | tls_error(US"SSL_new", host, NULL, errstr); | |
c05bdbd6 | 3242 | return FALSE; |
74f1a423 JH |
3243 | } |
3244 | SSL_set_session_id_context(exim_client_ctx->ssl, sid_ctx, Ustrlen(sid_ctx)); | |
b10c87b3 | 3245 | |
c05bdbd6 | 3246 | SSL_set_fd(exim_client_ctx->ssl, cctx->sock); |
74f1a423 | 3247 | SSL_set_connect_state(exim_client_ctx->ssl); |
059ec3d9 | 3248 | |
65867078 | 3249 | if (ob->tls_sni) |
3f0945ff | 3250 | { |
74f1a423 | 3251 | if (!expand_check(ob->tls_sni, US"tls_sni", &tlsp->sni, errstr)) |
c05bdbd6 | 3252 | return FALSE; |
74f1a423 | 3253 | if (!tlsp->sni) |
2c9a0e86 PP |
3254 | { |
3255 | DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n"); | |
3256 | } | |
74f1a423 JH |
3257 | else if (!Ustrlen(tlsp->sni)) |
3258 | tlsp->sni = NULL; | |
3f0945ff PP |
3259 | else |
3260 | { | |
35731706 | 3261 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
74f1a423 JH |
3262 | DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tlsp->sni); |
3263 | SSL_set_tlsext_host_name(exim_client_ctx->ssl, tlsp->sni); | |
35731706 | 3264 | #else |
66802652 | 3265 | log_write(0, LOG_MAIN, "SNI unusable with this OpenSSL library version; ignoring \"%s\"\n", |
74f1a423 | 3266 | tlsp->sni); |
35731706 | 3267 | #endif |
3f0945ff PP |
3268 | } |
3269 | } | |
3270 | ||
c0635b6d | 3271 | #ifdef SUPPORT_DANE |
c05bdbd6 JH |
3272 | if (conn_args->dane) |
3273 | if (dane_tlsa_load(exim_client_ctx->ssl, host, &conn_args->tlsa_dnsa, errstr) != OK) | |
3274 | return FALSE; | |
594706ea JH |
3275 | #endif |
3276 | ||
f2de3a33 | 3277 | #ifndef DISABLE_OCSP |
f5d78688 JH |
3278 | /* Request certificate status at connection-time. If the server |
3279 | does OCSP stapling we will get the callback (set in tls_init()) */ | |
c0635b6d | 3280 | # ifdef SUPPORT_DANE |
594706ea JH |
3281 | if (request_ocsp) |
3282 | { | |
3283 | const uschar * s; | |
41afb5cb JH |
3284 | if ( ((s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage")) |
3285 | || ((s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage")) | |
594706ea JH |
3286 | ) |
3287 | { /* Re-eval now $tls_out_tlsa_usage is populated. If | |
3288 | this means we avoid the OCSP request, we wasted the setup | |
3289 | cost in tls_init(). */ | |
3c07dd2d | 3290 | require_ocsp = verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK; |
5130845b | 3291 | request_ocsp = require_ocsp |
3c07dd2d | 3292 | || verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK; |
594706ea JH |
3293 | } |
3294 | } | |
b50c8b84 JH |
3295 | # endif |
3296 | ||
44662487 JH |
3297 | if (request_ocsp) |
3298 | { | |
74f1a423 | 3299 | SSL_set_tlsext_status_type(exim_client_ctx->ssl, TLSEXT_STATUSTYPE_ocsp); |
44662487 | 3300 | client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp; |
74f1a423 | 3301 | tlsp->ocsp = OCSP_NOT_RESP; |
44662487 | 3302 | } |
f5d78688 JH |
3303 | #endif |
3304 | ||
c82de233 JH |
3305 | #ifdef EXPERIMENTAL_TLS_RESUME |
3306 | if (!tls_client_ssl_resume_prehandshake(exim_client_ctx->ssl, tlsp, host, | |
3307 | errstr)) | |
3308 | return FALSE; | |
3309 | #endif | |
3310 | ||
0cbf2b82 | 3311 | #ifndef DISABLE_EVENT |
afdb5e9c | 3312 | client_static_cbinfo->event_action = tb ? tb->event_action : NULL; |
a7538db1 | 3313 | #endif |
043b1248 | 3314 | |
059ec3d9 PH |
3315 | /* There doesn't seem to be a built-in timeout on connection. */ |
3316 | ||
3317 | DEBUG(D_tls) debug_printf("Calling SSL_connect\n"); | |
3318 | sigalrm_seen = FALSE; | |
c2a1bba0 | 3319 | ALARM(ob->command_timeout); |
74f1a423 | 3320 | rc = SSL_connect(exim_client_ctx->ssl); |
c2a1bba0 | 3321 | ALARM_CLR(0); |
059ec3d9 | 3322 | |
c0635b6d | 3323 | #ifdef SUPPORT_DANE |
c05bdbd6 | 3324 | if (conn_args->dane) |
74f1a423 | 3325 | DANESSL_cleanup(exim_client_ctx->ssl); |
043b1248 JH |
3326 | #endif |
3327 | ||
059ec3d9 | 3328 | if (rc <= 0) |
74f1a423 JH |
3329 | { |
3330 | tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL, errstr); | |
c05bdbd6 | 3331 | return FALSE; |
74f1a423 | 3332 | } |
059ec3d9 | 3333 | |
f20cfa4a JH |
3334 | DEBUG(D_tls) |
3335 | { | |
3336 | debug_printf("SSL_connect succeeded\n"); | |
3337 | #ifdef EXIM_HAVE_OPENSSL_KEYLOG | |
3338 | { | |
10ed27e0 JH |
3339 | BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE); |
3340 | SSL_SESSION_print_keylog(bp, SSL_get_session(exim_client_ctx->ssl)); | |
3341 | BIO_free(bp); | |
f20cfa4a JH |
3342 | } |
3343 | #endif | |
3344 | } | |
059ec3d9 | 3345 | |
b10c87b3 JH |
3346 | #ifdef EXPERIMENTAL_TLS_RESUME |
3347 | tls_client_resume_posthandshake(exim_client_ctx, tlsp); | |
3348 | #endif | |
3349 | ||
74f1a423 | 3350 | peer_cert(exim_client_ctx->ssl, tlsp, peerdn, sizeof(peerdn)); |
059ec3d9 | 3351 | |
f1be21cf JH |
3352 | tlsp->cipher = construct_cipher_name(exim_client_ctx->ssl, &tlsp->bits); |
3353 | tlsp->cipher_stdname = cipher_stdname_ssl(exim_client_ctx->ssl); | |
059ec3d9 | 3354 | |
9d1c15ef JH |
3355 | /* Record the certificate we presented */ |
3356 | { | |
74f1a423 JH |
3357 | X509 * crt = SSL_get_certificate(exim_client_ctx->ssl); |
3358 | tlsp->ourcert = crt ? X509_dup(crt) : NULL; | |
9d1c15ef JH |
3359 | } |
3360 | ||
c05bdbd6 | 3361 | tlsp->active.sock = cctx->sock; |
74f1a423 | 3362 | tlsp->active.tls_ctx = exim_client_ctx; |
c05bdbd6 JH |
3363 | cctx->tls_ctx = exim_client_ctx; |
3364 | return TRUE; | |
059ec3d9 PH |
3365 | } |
3366 | ||
3367 | ||
3368 | ||
3369 | ||
3370 | ||
0d81dabc JH |
3371 | static BOOL |
3372 | tls_refill(unsigned lim) | |
3373 | { | |
3374 | int error; | |
3375 | int inbytes; | |
3376 | ||
3377 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl, | |
3378 | ssl_xfer_buffer, ssl_xfer_buffer_size); | |
3379 | ||
c2a1bba0 | 3380 | if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); |
0d81dabc JH |
3381 | inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, |
3382 | MIN(ssl_xfer_buffer_size, lim)); | |
3383 | error = SSL_get_error(server_ssl, inbytes); | |
c2a1bba0 | 3384 | if (smtp_receive_timeout > 0) ALARM_CLR(0); |
9723f966 JH |
3385 | |
3386 | if (had_command_timeout) /* set by signal handler */ | |
3387 | smtp_command_timeout_exit(); /* does not return */ | |
3388 | if (had_command_sigterm) | |
3389 | smtp_command_sigterm_exit(); | |
3390 | if (had_data_timeout) | |
3391 | smtp_data_timeout_exit(); | |
3392 | if (had_data_sigint) | |
3393 | smtp_data_sigint_exit(); | |
0d81dabc JH |
3394 | |
3395 | /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been | |
3396 | closed down, not that the socket itself has been closed down. Revert to | |
3397 | non-SSL handling. */ | |
3398 | ||
74f1a423 | 3399 | switch(error) |
0d81dabc | 3400 | { |
74f1a423 JH |
3401 | case SSL_ERROR_NONE: |
3402 | break; | |
3403 | ||
3404 | case SSL_ERROR_ZERO_RETURN: | |
3405 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
0d81dabc | 3406 | |
74f1a423 JH |
3407 | if (SSL_get_shutdown(server_ssl) == SSL_RECEIVED_SHUTDOWN) |
3408 | SSL_shutdown(server_ssl); | |
dec766a1 | 3409 | |
bd231acd | 3410 | tls_close(NULL, TLS_NO_SHUTDOWN); |
74f1a423 | 3411 | return FALSE; |
0d81dabc | 3412 | |
74f1a423 JH |
3413 | /* Handle genuine errors */ |
3414 | case SSL_ERROR_SSL: | |
0abc5a13 | 3415 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
74f1a423 JH |
3416 | log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); |
3417 | ssl_xfer_error = TRUE; | |
3418 | return FALSE; | |
0d81dabc | 3419 | |
74f1a423 JH |
3420 | default: |
3421 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
3422 | DEBUG(D_tls) if (error == SSL_ERROR_SYSCALL) | |
3423 | debug_printf(" - syscall %s\n", strerror(errno)); | |
3424 | ssl_xfer_error = TRUE; | |
3425 | return FALSE; | |
0d81dabc JH |
3426 | } |
3427 | ||
3428 | #ifndef DISABLE_DKIM | |
3429 | dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); | |
3430 | #endif | |
3431 | ssl_xfer_buffer_hwm = inbytes; | |
3432 | ssl_xfer_buffer_lwm = 0; | |
3433 | return TRUE; | |
3434 | } | |
3435 | ||
3436 | ||
059ec3d9 PH |
3437 | /************************************************* |
3438 | * TLS version of getc * | |
3439 | *************************************************/ | |
3440 | ||
3441 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
3442 | it refills the buffer via the SSL reading function. | |
3443 | ||
bd8fbe36 | 3444 | Arguments: lim Maximum amount to read/buffer |
059ec3d9 | 3445 | Returns: the next character or EOF |
817d9f57 JH |
3446 | |
3447 | Only used by the server-side TLS. | |
059ec3d9 PH |
3448 | */ |
3449 | ||
3450 | int | |
bd8fbe36 | 3451 | tls_getc(unsigned lim) |
059ec3d9 PH |
3452 | { |
3453 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) | |
0d81dabc JH |
3454 | if (!tls_refill(lim)) |
3455 | return ssl_xfer_error ? EOF : smtp_getc(lim); | |
059ec3d9 | 3456 | |
0d81dabc | 3457 | /* Something in the buffer; return next uschar */ |
059ec3d9 | 3458 | |
0d81dabc JH |
3459 | return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; |
3460 | } | |
059ec3d9 | 3461 | |
0d81dabc JH |
3462 | uschar * |
3463 | tls_getbuf(unsigned * len) | |
3464 | { | |
3465 | unsigned size; | |
3466 | uschar * buf; | |
ba084640 | 3467 | |
0d81dabc JH |
3468 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) |
3469 | if (!tls_refill(*len)) | |
059ec3d9 | 3470 | { |
0d81dabc JH |
3471 | if (!ssl_xfer_error) return smtp_getbuf(len); |
3472 | *len = 0; | |
3473 | return NULL; | |
059ec3d9 | 3474 | } |
c80c5570 | 3475 | |
0d81dabc JH |
3476 | if ((size = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm) > *len) |
3477 | size = *len; | |
3478 | buf = &ssl_xfer_buffer[ssl_xfer_buffer_lwm]; | |
3479 | ssl_xfer_buffer_lwm += size; | |
3480 | *len = size; | |
3481 | return buf; | |
059ec3d9 PH |
3482 | } |
3483 | ||
0d81dabc | 3484 | |
584e96c6 JH |
3485 | void |
3486 | tls_get_cache() | |
3487 | { | |
9960d1e5 | 3488 | #ifndef DISABLE_DKIM |
584e96c6 JH |
3489 | int n = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm; |
3490 | if (n > 0) | |
3491 | dkim_exim_verify_feed(ssl_xfer_buffer+ssl_xfer_buffer_lwm, n); | |
584e96c6 | 3492 | #endif |
9960d1e5 | 3493 | } |
584e96c6 | 3494 | |
059ec3d9 | 3495 | |
925ac8e4 JH |
3496 | BOOL |
3497 | tls_could_read(void) | |
3498 | { | |
a5ffa9b4 | 3499 | return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm || SSL_pending(server_ssl) > 0; |
925ac8e4 JH |
3500 | } |
3501 | ||
059ec3d9 PH |
3502 | |
3503 | /************************************************* | |
3504 | * Read bytes from TLS channel * | |
3505 | *************************************************/ | |
3506 | ||
3507 | /* | |
3508 | Arguments: | |
74f1a423 | 3509 | ct_ctx client context pointer, or NULL for the one global server context |
059ec3d9 PH |
3510 | buff buffer of data |
3511 | len size of buffer | |
3512 | ||
3513 | Returns: the number of bytes read | |
afdb5e9c | 3514 | -1 after a failed read, including EOF |
817d9f57 JH |
3515 | |
3516 | Only used by the client-side TLS. | |
059ec3d9 PH |
3517 | */ |
3518 | ||
3519 | int | |
74f1a423 | 3520 | tls_read(void * ct_ctx, uschar *buff, size_t len) |
059ec3d9 | 3521 | { |
74f1a423 | 3522 | SSL * ssl = ct_ctx ? ((exim_openssl_client_tls_ctx *)ct_ctx)->ssl : server_ssl; |
059ec3d9 PH |
3523 | int inbytes; |
3524 | int error; | |
3525 | ||
389ca47a | 3526 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl, |
c80c5570 | 3527 | buff, (unsigned int)len); |
059ec3d9 | 3528 | |
389ca47a JH |
3529 | inbytes = SSL_read(ssl, CS buff, len); |
3530 | error = SSL_get_error(ssl, inbytes); | |
059ec3d9 PH |
3531 | |
3532 | if (error == SSL_ERROR_ZERO_RETURN) | |
3533 | { | |
3534 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
3535 | return -1; | |
3536 | } | |
3537 | else if (error != SSL_ERROR_NONE) | |
059ec3d9 | 3538 | return -1; |
059ec3d9 PH |
3539 | |
3540 | return inbytes; | |
3541 | } | |
3542 | ||
3543 | ||
3544 | ||
3545 | ||
3546 | ||
3547 | /************************************************* | |
3548 | * Write bytes down TLS channel * | |
3549 | *************************************************/ | |
3550 | ||
3551 | /* | |
3552 | Arguments: | |
74f1a423 | 3553 | ct_ctx client context pointer, or NULL for the one global server context |
059ec3d9 PH |
3554 | buff buffer of data |
3555 | len number of bytes | |
925ac8e4 | 3556 | more further data expected soon |
059ec3d9 PH |
3557 | |
3558 | Returns: the number of bytes after a successful write, | |
3559 | -1 after a failed write | |
817d9f57 JH |
3560 | |
3561 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
3562 | */ |
3563 | ||
3564 | int | |
74f1a423 | 3565 | tls_write(void * ct_ctx, const uschar *buff, size_t len, BOOL more) |
059ec3d9 | 3566 | { |
ac35befe | 3567 | size_t olen = len; |
d7978c0f | 3568 | int outbytes, error; |
c09dbcfb JH |
3569 | SSL * ssl = ct_ctx |
3570 | ? ((exim_openssl_client_tls_ctx *)ct_ctx)->ssl : server_ssl; | |
3571 | static gstring * server_corked = NULL; | |
3572 | gstring ** corkedp = ct_ctx | |
3573 | ? &((exim_openssl_client_tls_ctx *)ct_ctx)->corked : &server_corked; | |
3574 | gstring * corked = *corkedp; | |
a5ffa9b4 | 3575 | |
ef698bf6 | 3576 | DEBUG(D_tls) debug_printf("%s(%p, %lu%s)\n", __FUNCTION__, |
b93be52e | 3577 | buff, (unsigned long)len, more ? ", more" : ""); |
a5ffa9b4 JH |
3578 | |
3579 | /* Lacking a CORK or MSG_MORE facility (such as GnuTLS has) we copy data when | |
3580 | "more" is notified. This hack is only ok if small amounts are involved AND only | |
3581 | one stream does it, in one context (i.e. no store reset). Currently it is used | |
c09dbcfb JH |
3582 | for the responses to the received SMTP MAIL , RCPT, DATA sequence, only. |
3583 | We support callouts done by the server process by using a separate client | |
3584 | context for the stashed information. */ | |
ac35befe JH |
3585 | /* + if PIPE_COMMAND, banner & ehlo-resp for smmtp-on-connect. Suspect there's |
3586 | a store reset there, so use POOL_PERM. */ | |
3587 | /* + if CHUNKING, cmds EHLO,MAIL,RCPT(s),BDAT */ | |
a5ffa9b4 | 3588 | |
ac35befe | 3589 | if ((more || corked)) |
a5ffa9b4 | 3590 | { |
4e48d56c | 3591 | #ifdef SUPPORT_PIPE_CONNECT |
ee8b8090 JH |
3592 | int save_pool = store_pool; |
3593 | store_pool = POOL_PERM; | |
3594 | #endif | |
3595 | ||
acec9514 | 3596 | corked = string_catn(corked, buff, len); |
ee8b8090 | 3597 | |
4e48d56c | 3598 | #ifdef SUPPORT_PIPE_CONNECT |
ee8b8090 JH |
3599 | store_pool = save_pool; |
3600 | #endif | |
3601 | ||
a5ffa9b4 | 3602 | if (more) |
c09dbcfb JH |
3603 | { |
3604 | *corkedp = corked; | |
a5ffa9b4 | 3605 | return len; |
c09dbcfb | 3606 | } |
acec9514 JH |
3607 | buff = CUS corked->s; |
3608 | len = corked->ptr; | |
c09dbcfb | 3609 | *corkedp = NULL; |
a5ffa9b4 | 3610 | } |
059ec3d9 | 3611 | |
d7978c0f | 3612 | for (int left = len; left > 0;) |
059ec3d9 | 3613 | { |
74f1a423 | 3614 | DEBUG(D_tls) debug_printf("SSL_write(%p, %p, %d)\n", ssl, buff, left); |
059ec3d9 PH |
3615 | outbytes = SSL_write(ssl, CS buff, left); |
3616 | error = SSL_get_error(ssl, outbytes); | |
3617 | DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error); | |
3618 | switch (error) | |
3619 | { | |
3620 | case SSL_ERROR_SSL: | |
0abc5a13 | 3621 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
96f5fe4c JH |
3622 | log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); |
3623 | return -1; | |
059ec3d9 PH |
3624 | |
3625 | case SSL_ERROR_NONE: | |
96f5fe4c JH |
3626 | left -= outbytes; |
3627 | buff += outbytes; | |
3628 | break; | |
059ec3d9 PH |
3629 | |
3630 | case SSL_ERROR_ZERO_RETURN: | |
96f5fe4c JH |
3631 | log_write(0, LOG_MAIN, "SSL channel closed on write"); |
3632 | return -1; | |
059ec3d9 | 3633 | |
817d9f57 | 3634 | case SSL_ERROR_SYSCALL: |
96f5fe4c JH |
3635 | log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", |
3636 | sender_fullhost ? sender_fullhost : US"<unknown>", | |
3637 | strerror(errno)); | |
3638 | return -1; | |
817d9f57 | 3639 | |
059ec3d9 | 3640 | default: |
96f5fe4c JH |
3641 | log_write(0, LOG_MAIN, "SSL_write error %d", error); |
3642 | return -1; | |
059ec3d9 PH |
3643 | } |
3644 | } | |
ac35befe | 3645 | return olen; |
059ec3d9 PH |
3646 | } |
3647 | ||
3648 | ||
3649 | ||
3650 | /************************************************* | |
3651 | * Close down a TLS session * | |
3652 | *************************************************/ | |
3653 | ||
3654 | /* This is also called from within a delivery subprocess forked from the | |
3655 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
3656 | would tamper with the SSL session in the parent process). | |
3657 | ||
dec766a1 | 3658 | Arguments: |
74f1a423 | 3659 | ct_ctx client TLS context pointer, or NULL for the one global server context |
dec766a1 WB |
3660 | shutdown 1 if TLS close-alert is to be sent, |
3661 | 2 if also response to be waited for | |
3662 | ||
059ec3d9 | 3663 | Returns: nothing |
817d9f57 JH |
3664 | |
3665 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
3666 | */ |
3667 | ||
3668 | void | |
74f1a423 | 3669 | tls_close(void * ct_ctx, int shutdown) |
059ec3d9 | 3670 | { |
74f1a423 JH |
3671 | exim_openssl_client_tls_ctx * o_ctx = ct_ctx; |
3672 | SSL_CTX **ctxp = o_ctx ? &o_ctx->ctx : &server_ctx; | |
3673 | SSL **sslp = o_ctx ? &o_ctx->ssl : &server_ssl; | |
3674 | int *fdp = o_ctx ? &tls_out.active.sock : &tls_in.active.sock; | |
817d9f57 JH |
3675 | |
3676 | if (*fdp < 0) return; /* TLS was not active */ | |
059ec3d9 PH |
3677 | |
3678 | if (shutdown) | |
3679 | { | |
dec766a1 WB |
3680 | int rc; |
3681 | DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n", | |
3682 | shutdown > 1 ? " (with response-wait)" : ""); | |
3683 | ||
3684 | if ( (rc = SSL_shutdown(*sslp)) == 0 /* send "close notify" alert */ | |
3685 | && shutdown > 1) | |
3686 | { | |
c2a1bba0 | 3687 | ALARM(2); |
dec766a1 | 3688 | rc = SSL_shutdown(*sslp); /* wait for response */ |
c2a1bba0 | 3689 | ALARM_CLR(0); |
dec766a1 WB |
3690 | } |
3691 | ||
3692 | if (rc < 0) DEBUG(D_tls) | |
3693 | { | |
0abc5a13 | 3694 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
dec766a1 WB |
3695 | debug_printf("SSL_shutdown: %s\n", ssl_errstring); |
3696 | } | |
3697 | } | |
3698 | ||
74f1a423 | 3699 | if (!o_ctx) /* server side */ |
dec766a1 | 3700 | { |
bd231acd | 3701 | #ifndef DISABLE_OCSP |
dec766a1 | 3702 | sk_X509_pop_free(server_static_cbinfo->verify_stack, X509_free); |
dec766a1 | 3703 | server_static_cbinfo->verify_stack = NULL; |
37f0ce65 | 3704 | #endif |
059ec3d9 | 3705 | |
bd231acd JH |
3706 | receive_getc = smtp_getc; |
3707 | receive_getbuf = smtp_getbuf; | |
3708 | receive_get_cache = smtp_get_cache; | |
3709 | receive_ungetc = smtp_ungetc; | |
3710 | receive_feof = smtp_feof; | |
3711 | receive_ferror = smtp_ferror; | |
3712 | receive_smtp_buffered = smtp_buffered; | |
3713 | tls_in.active.tls_ctx = NULL; | |
3714 | tls_in.sni = NULL; | |
3715 | /* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */ | |
3716 | } | |
3717 | ||
dec766a1 | 3718 | SSL_CTX_free(*ctxp); |
817d9f57 | 3719 | SSL_free(*sslp); |
dec766a1 | 3720 | *ctxp = NULL; |
817d9f57 | 3721 | *sslp = NULL; |
817d9f57 | 3722 | *fdp = -1; |
059ec3d9 PH |
3723 | } |
3724 | ||
36f12725 NM |
3725 | |
3726 | ||
3727 | ||
3375e053 PP |
3728 | /************************************************* |
3729 | * Let tls_require_ciphers be checked at startup * | |
3730 | *************************************************/ | |
3731 | ||
3732 | /* The tls_require_ciphers option, if set, must be something which the | |
3733 | library can parse. | |
3734 | ||
3735 | Returns: NULL on success, or error message | |
3736 | */ | |
3737 | ||
3738 | uschar * | |
3739 | tls_validate_require_cipher(void) | |
3740 | { | |
3741 | SSL_CTX *ctx; | |
3742 | uschar *s, *expciphers, *err; | |
3743 | ||
b038d456 | 3744 | tls_openssl_init(); |
3375e053 PP |
3745 | |
3746 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
3747 | return NULL; | |
3748 | ||
cf0c6164 JH |
3749 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers, |
3750 | &err)) | |
3375e053 PP |
3751 | return US"failed to expand tls_require_ciphers"; |
3752 | ||
3753 | if (!(expciphers && *expciphers)) | |
3754 | return NULL; | |
3755 | ||
3756 | /* normalisation ripped from above */ | |
3757 | s = expciphers; | |
3758 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
3759 | ||
3760 | err = NULL; | |
3761 | ||
7a8b9519 JH |
3762 | #ifdef EXIM_HAVE_OPENSSL_TLS_METHOD |
3763 | if (!(ctx = SSL_CTX_new(TLS_server_method()))) | |
3764 | #else | |
3765 | if (!(ctx = SSL_CTX_new(SSLv23_server_method()))) | |
3766 | #endif | |
3375e053 | 3767 | { |
0abc5a13 | 3768 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
3375e053 PP |
3769 | return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring); |
3770 | } | |
3771 | ||
3772 | DEBUG(D_tls) | |
3773 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
3774 | ||
3775 | if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) | |
3776 | { | |
0abc5a13 | 3777 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
cf0c6164 JH |
3778 | err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed: %s", |
3779 | expciphers, ssl_errstring); | |
3375e053 PP |
3780 | } |
3781 | ||
3782 | SSL_CTX_free(ctx); | |
3783 | ||
3784 | return err; | |
3785 | } | |
3786 | ||
3787 | ||
3788 | ||
3789 | ||
36f12725 NM |
3790 | /************************************************* |
3791 | * Report the library versions. * | |
3792 | *************************************************/ | |
3793 | ||
3794 | /* There have historically been some issues with binary compatibility in | |
3795 | OpenSSL libraries; if Exim (like many other applications) is built against | |
3796 | one version of OpenSSL but the run-time linker picks up another version, | |
3797 | it can result in serious failures, including crashing with a SIGSEGV. So | |
3798 | report the version found by the compiler and the run-time version. | |
3799 | ||
f64a1e23 PP |
3800 | Note: some OS vendors backport security fixes without changing the version |
3801 | number/string, and the version date remains unchanged. The _build_ date | |
3802 | will change, so we can more usefully assist with version diagnosis by also | |
3803 | reporting the build date. | |
3804 | ||
36f12725 NM |
3805 | Arguments: a FILE* to print the results to |
3806 | Returns: nothing | |
3807 | */ | |
3808 | ||
3809 | void | |
3810 | tls_version_report(FILE *f) | |
3811 | { | |
754a0503 | 3812 | fprintf(f, "Library version: OpenSSL: Compile: %s\n" |
f64a1e23 PP |
3813 | " Runtime: %s\n" |
3814 | " : %s\n", | |
754a0503 | 3815 | OPENSSL_VERSION_TEXT, |
f64a1e23 PP |
3816 | SSLeay_version(SSLEAY_VERSION), |
3817 | SSLeay_version(SSLEAY_BUILT_ON)); | |
3818 | /* third line is 38 characters for the %s and the line is 73 chars long; | |
3819 | the OpenSSL output includes a "built on: " prefix already. */ | |
36f12725 NM |
3820 | } |
3821 | ||
9e3331ea TK |
3822 | |
3823 | ||
3824 | ||
3825 | /************************************************* | |
17c76198 | 3826 | * Random number generation * |
9e3331ea TK |
3827 | *************************************************/ |
3828 | ||
3829 | /* Pseudo-random number generation. The result is not expected to be | |
3830 | cryptographically strong but not so weak that someone will shoot themselves | |
3831 | in the foot using it as a nonce in input in some email header scheme or | |
3832 | whatever weirdness they'll twist this into. The result should handle fork() | |
3833 | and avoid repeating sequences. OpenSSL handles that for us. | |
3834 | ||
3835 | Arguments: | |
3836 | max range maximum | |
3837 | Returns a random number in range [0, max-1] | |
3838 | */ | |
3839 | ||
3840 | int | |
17c76198 | 3841 | vaguely_random_number(int max) |
9e3331ea TK |
3842 | { |
3843 | unsigned int r; | |
3844 | int i, needed_len; | |
de6135a0 PP |
3845 | static pid_t pidlast = 0; |
3846 | pid_t pidnow; | |
9e3331ea TK |
3847 | uschar smallbuf[sizeof(r)]; |
3848 | ||
3849 | if (max <= 1) | |
3850 | return 0; | |
3851 | ||
de6135a0 PP |
3852 | pidnow = getpid(); |
3853 | if (pidnow != pidlast) | |
3854 | { | |
3855 | /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state | |
3856 | is unique for each thread", this doesn't apparently apply across processes, | |
3857 | so our own warning from vaguely_random_number_fallback() applies here too. | |
3858 | Fix per PostgreSQL. */ | |
3859 | if (pidlast != 0) | |
3860 | RAND_cleanup(); | |
3861 | pidlast = pidnow; | |
3862 | } | |
3863 | ||
9e3331ea TK |
3864 | /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ |
3865 | if (!RAND_status()) | |
3866 | { | |
3867 | randstuff r; | |
3868 | gettimeofday(&r.tv, NULL); | |
3869 | r.p = getpid(); | |
3870 | ||
5903c6ff | 3871 | RAND_seed(US (&r), sizeof(r)); |
9e3331ea TK |
3872 | } |
3873 | /* We're after pseudo-random, not random; if we still don't have enough data | |
3874 | in the internal PRNG then our options are limited. We could sleep and hope | |
3875 | for entropy to come along (prayer technique) but if the system is so depleted | |
3876 | in the first place then something is likely to just keep taking it. Instead, | |
3877 | we'll just take whatever little bit of pseudo-random we can still manage to | |
3878 | get. */ | |
3879 | ||
3880 | needed_len = sizeof(r); | |
3881 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
3882 | asked for a number less than 10. */ | |
3883 | for (r = max, i = 0; r; ++i) | |
3884 | r >>= 1; | |
3885 | i = (i + 7) / 8; | |
3886 | if (i < needed_len) | |
3887 | needed_len = i; | |
3888 | ||
c8dfb21d | 3889 | #ifdef EXIM_HAVE_RAND_PSEUDO |
9e3331ea | 3890 | /* We do not care if crypto-strong */ |
17c76198 | 3891 | i = RAND_pseudo_bytes(smallbuf, needed_len); |
c8dfb21d JH |
3892 | #else |
3893 | i = RAND_bytes(smallbuf, needed_len); | |
3894 | #endif | |
3895 | ||
17c76198 PP |
3896 | if (i < 0) |
3897 | { | |
3898 | DEBUG(D_all) | |
3899 | debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n"); | |
3900 | return vaguely_random_number_fallback(max); | |
3901 | } | |
3902 | ||
9e3331ea | 3903 | r = 0; |
d7978c0f JH |
3904 | for (uschar * p = smallbuf; needed_len; --needed_len, ++p) |
3905 | r = 256 * r + *p; | |
9e3331ea TK |
3906 | |
3907 | /* We don't particularly care about weighted results; if someone wants | |
3908 | smooth distribution and cares enough then they should submit a patch then. */ | |
3909 | return r % max; | |
3910 | } | |
3911 | ||
77bb000f PP |
3912 | |
3913 | ||
3914 | ||
3915 | /************************************************* | |
3916 | * OpenSSL option parse * | |
3917 | *************************************************/ | |
3918 | ||
3919 | /* Parse one option for tls_openssl_options_parse below | |
3920 | ||
3921 | Arguments: | |
3922 | name one option name | |
3923 | value place to store a value for it | |
3924 | Returns success or failure in parsing | |
3925 | */ | |
3926 | ||
77bb000f | 3927 | |
c80c5570 | 3928 | |
77bb000f PP |
3929 | static BOOL |
3930 | tls_openssl_one_option_parse(uschar *name, long *value) | |
3931 | { | |
3932 | int first = 0; | |
3933 | int last = exim_openssl_options_size; | |
3934 | while (last > first) | |
3935 | { | |
3936 | int middle = (first + last)/2; | |
3937 | int c = Ustrcmp(name, exim_openssl_options[middle].name); | |
3938 | if (c == 0) | |
3939 | { | |
3940 | *value = exim_openssl_options[middle].value; | |
3941 | return TRUE; | |
3942 | } | |
3943 | else if (c > 0) | |
3944 | first = middle + 1; | |
3945 | else | |
3946 | last = middle; | |
3947 | } | |
3948 | return FALSE; | |
3949 | } | |
3950 | ||
3951 | ||
3952 | ||
3953 | ||
3954 | /************************************************* | |
3955 | * OpenSSL option parsing logic * | |
3956 | *************************************************/ | |
3957 | ||
3958 | /* OpenSSL has a number of compatibility options which an administrator might | |
3959 | reasonably wish to set. Interpret a list similarly to decode_bits(), so that | |
3960 | we look like log_selector. | |
3961 | ||
3962 | Arguments: | |
3963 | option_spec the administrator-supplied string of options | |
3964 | results ptr to long storage for the options bitmap | |
3965 | Returns success or failure | |
3966 | */ | |
3967 | ||
3968 | BOOL | |
3969 | tls_openssl_options_parse(uschar *option_spec, long *results) | |
3970 | { | |
3971 | long result, item; | |
86ede124 | 3972 | uschar * exp, * end; |
77bb000f PP |
3973 | uschar keep_c; |
3974 | BOOL adding, item_parsed; | |
3975 | ||
b10c87b3 | 3976 | /* Server: send no (<= TLS1.2) session tickets */ |
7006ee24 | 3977 | result = SSL_OP_NO_TICKET; |
b10c87b3 | 3978 | |
b1770b6e | 3979 | /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed |
86ede124 | 3980 | from default because it increases BEAST susceptibility. */ |
f0f5a555 PP |
3981 | #ifdef SSL_OP_NO_SSLv2 |
3982 | result |= SSL_OP_NO_SSLv2; | |
3983 | #endif | |
b10c87b3 JH |
3984 | #ifdef SSL_OP_NO_SSLv3 |
3985 | result |= SSL_OP_NO_SSLv3; | |
3986 | #endif | |
a57b6200 JH |
3987 | #ifdef SSL_OP_SINGLE_DH_USE |
3988 | result |= SSL_OP_SINGLE_DH_USE; | |
3989 | #endif | |
77bb000f | 3990 | |
7006ee24 | 3991 | if (!option_spec) |
77bb000f PP |
3992 | { |
3993 | *results = result; | |
3994 | return TRUE; | |
3995 | } | |
3996 | ||
86ede124 JH |
3997 | if (!expand_check(option_spec, US"openssl_options", &exp, &end)) |
3998 | return FALSE; | |
3999 | ||
4000 | for (uschar * s = exp; *s; /**/) | |
77bb000f PP |
4001 | { |
4002 | while (isspace(*s)) ++s; | |
4003 | if (*s == '\0') | |
4004 | break; | |
4005 | if (*s != '+' && *s != '-') | |
4006 | { | |
4007 | DEBUG(D_tls) debug_printf("malformed openssl option setting: " | |
0e944a0d | 4008 | "+ or - expected but found \"%s\"\n", s); |
77bb000f PP |
4009 | return FALSE; |
4010 | } | |
4011 | adding = *s++ == '+'; | |
4012 | for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; | |
4013 | keep_c = *end; | |
4014 | *end = '\0'; | |
4015 | item_parsed = tls_openssl_one_option_parse(s, &item); | |
96f5fe4c | 4016 | *end = keep_c; |
77bb000f PP |
4017 | if (!item_parsed) |
4018 | { | |
0e944a0d | 4019 | DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); |
77bb000f PP |
4020 | return FALSE; |
4021 | } | |
f97ca6d1 JH |
4022 | DEBUG(D_tls) debug_printf("openssl option, %s %8lx: %lx (%s)\n", |
4023 | adding ? "adding to " : "removing from", result, item, s); | |
77bb000f PP |
4024 | if (adding) |
4025 | result |= item; | |
4026 | else | |
4027 | result &= ~item; | |
77bb000f PP |
4028 | s = end; |
4029 | } | |
4030 | ||
4031 | *results = result; | |
4032 | return TRUE; | |
4033 | } | |
4034 | ||
8442641e | 4035 | #endif /*!MACRO_PREDEF*/ |
9d1c15ef JH |
4036 | /* vi: aw ai sw=2 |
4037 | */ | |
059ec3d9 | 4038 | /* End of tls-openssl.c */ |