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