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 | |
49 | #else | |
50 | # define EXIM_HAVE_EPHEM_RSA_KEX | |
51 | # define EXIM_HAVE_RAND_PSEUDO | |
52 | #endif | |
53 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) | |
8442641e | 54 | # define EXIM_HAVE_SHA256 |
c8dfb21d | 55 | #endif |
34e3241d | 56 | |
d7978c0f JH |
57 | /* X509_check_host provides sane certificate hostname checking, but was added |
58 | to OpenSSL late, after other projects forked off the code-base. So in | |
59 | addition to guarding against the base version number, beware that LibreSSL | |
60 | does not (at this time) support this function. | |
61 | ||
62 | If LibreSSL gains a different API, perhaps via libtls, then we'll probably | |
63 | opt to disentangle and ask a LibreSSL user to provide glue for a third | |
64 | crypto provider for libtls instead of continuing to tie the OpenSSL glue | |
65 | into even twistier knots. If LibreSSL gains the same API, we can just | |
66 | change this guard and punt the issue for a while longer. */ | |
67 | ||
34e3241d PP |
68 | #ifndef LIBRESSL_VERSION_NUMBER |
69 | # if OPENSSL_VERSION_NUMBER >= 0x010100000L | |
70 | # define EXIM_HAVE_OPENSSL_CHECKHOST | |
8420742d | 71 | # define EXIM_HAVE_OPENSSL_DH_BITS |
7a8b9519 | 72 | # define EXIM_HAVE_OPENSSL_TLS_METHOD |
f20cfa4a | 73 | # define EXIM_HAVE_OPENSSL_KEYLOG |
f1be21cf | 74 | # define EXIM_HAVE_OPENSSL_CIPHER_GET_ID |
b10c87b3 | 75 | # define EXIM_HAVE_SESSION_TICKET |
e570d136 | 76 | # define EXIM_HAVE_OPESSL_TRACE |
012dd02e | 77 | # define EXIM_HAVE_OPESSL_GET0_SERIAL |
7434882d JH |
78 | # else |
79 | # define EXIM_NEED_OPENSSL_INIT | |
34e3241d PP |
80 | # endif |
81 | # if OPENSSL_VERSION_NUMBER >= 0x010000000L \ | |
2dfb468b | 82 | && (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L |
34e3241d PP |
83 | # define EXIM_HAVE_OPENSSL_CHECKHOST |
84 | # endif | |
11aa88b0 | 85 | #endif |
10ca4f1c | 86 | |
11aa88b0 RA |
87 | #if !defined(LIBRESSL_VERSION_NUMBER) \ |
88 | || LIBRESSL_VERSION_NUMBER >= 0x20010000L | |
10ca4f1c JH |
89 | # if !defined(OPENSSL_NO_ECDH) |
90 | # if OPENSSL_VERSION_NUMBER >= 0x0090800fL | |
8442641e | 91 | # define EXIM_HAVE_ECDH |
10ca4f1c JH |
92 | # endif |
93 | # if OPENSSL_VERSION_NUMBER >= 0x10002000L | |
10ca4f1c JH |
94 | # define EXIM_HAVE_OPENSSL_EC_NIST2NID |
95 | # endif | |
96 | # endif | |
2dfb468b | 97 | #endif |
3bcbbbe2 | 98 | |
8a40db1c JH |
99 | #ifndef LIBRESSL_VERSION_NUMBER |
100 | # if OPENSSL_VERSION_NUMBER >= 0x010101000L | |
101 | # define OPENSSL_HAVE_KEYLOG_CB | |
d7f31bb6 | 102 | # define OPENSSL_HAVE_NUM_TICKETS |
f1be21cf | 103 | # define EXIM_HAVE_OPENSSL_CIPHER_STD_NAME |
8a40db1c JH |
104 | # endif |
105 | #endif | |
106 | ||
67791ce4 JH |
107 | #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP) |
108 | # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile" | |
109 | # define DISABLE_OCSP | |
110 | #endif | |
43e2db44 JH |
111 | |
112 | #ifdef EXPERIMENTAL_TLS_RESUME | |
113 | # if OPENSSL_VERSION_NUMBER < 0x0101010L | |
114 | # error OpenSSL version too old for session-resumption | |
115 | # endif | |
116 | #endif | |
67791ce4 | 117 | |
a6510420 JH |
118 | #ifdef EXIM_HAVE_OPENSSL_CHECKHOST |
119 | # include <openssl/x509v3.h> | |
120 | #endif | |
121 | ||
f1be21cf JH |
122 | #ifndef EXIM_HAVE_OPENSSL_CIPHER_STD_NAME |
123 | # ifndef EXIM_HAVE_OPENSSL_CIPHER_GET_ID | |
124 | # define SSL_CIPHER_get_id(c) (c->id) | |
125 | # endif | |
dca6d121 JH |
126 | # ifndef MACRO_PREDEF |
127 | # include "tls-cipher-stdname.c" | |
128 | # endif | |
f1be21cf JH |
129 | #endif |
130 | ||
8442641e JH |
131 | /************************************************* |
132 | * OpenSSL option parse * | |
133 | *************************************************/ | |
134 | ||
135 | typedef struct exim_openssl_option { | |
136 | uschar *name; | |
137 | long value; | |
138 | } exim_openssl_option; | |
139 | /* We could use a macro to expand, but we need the ifdef and not all the | |
140 | options document which version they were introduced in. Policylet: include | |
141 | all options unless explicitly for DTLS, let the administrator choose which | |
142 | to apply. | |
143 | ||
144 | This list is current as of: | |
145 | ==> 1.0.1b <== | |
146 | Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev | |
147 | Plus SSL_OP_NO_TLSv1_3 for 1.1.2-dev | |
148 | */ | |
149 | static exim_openssl_option exim_openssl_options[] = { | |
150 | /* KEEP SORTED ALPHABETICALLY! */ | |
151 | #ifdef SSL_OP_ALL | |
6d95688d | 152 | { US"all", (long) SSL_OP_ALL }, |
8442641e JH |
153 | #endif |
154 | #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION | |
155 | { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, | |
156 | #endif | |
157 | #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE | |
158 | { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, | |
159 | #endif | |
160 | #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS | |
161 | { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, | |
162 | #endif | |
163 | #ifdef SSL_OP_EPHEMERAL_RSA | |
164 | { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, | |
165 | #endif | |
166 | #ifdef SSL_OP_LEGACY_SERVER_CONNECT | |
167 | { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, | |
168 | #endif | |
169 | #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER | |
170 | { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, | |
171 | #endif | |
172 | #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG | |
173 | { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, | |
174 | #endif | |
175 | #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING | |
176 | { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, | |
177 | #endif | |
178 | #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG | |
179 | { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, | |
180 | #endif | |
181 | #ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG | |
182 | { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, | |
183 | #endif | |
184 | #ifdef SSL_OP_NO_COMPRESSION | |
185 | { US"no_compression", SSL_OP_NO_COMPRESSION }, | |
186 | #endif | |
187 | #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION | |
188 | { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, | |
189 | #endif | |
190 | #ifdef SSL_OP_NO_SSLv2 | |
191 | { US"no_sslv2", SSL_OP_NO_SSLv2 }, | |
192 | #endif | |
193 | #ifdef SSL_OP_NO_SSLv3 | |
194 | { US"no_sslv3", SSL_OP_NO_SSLv3 }, | |
195 | #endif | |
196 | #ifdef SSL_OP_NO_TICKET | |
197 | { US"no_ticket", SSL_OP_NO_TICKET }, | |
198 | #endif | |
199 | #ifdef SSL_OP_NO_TLSv1 | |
200 | { US"no_tlsv1", SSL_OP_NO_TLSv1 }, | |
201 | #endif | |
202 | #ifdef SSL_OP_NO_TLSv1_1 | |
203 | #if SSL_OP_NO_TLSv1_1 == 0x00000400L | |
204 | /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */ | |
205 | #warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring | |
206 | #else | |
207 | { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 }, | |
208 | #endif | |
209 | #endif | |
210 | #ifdef SSL_OP_NO_TLSv1_2 | |
211 | { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 }, | |
212 | #endif | |
213 | #ifdef SSL_OP_NO_TLSv1_3 | |
214 | { US"no_tlsv1_3", SSL_OP_NO_TLSv1_3 }, | |
215 | #endif | |
216 | #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG | |
217 | { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG }, | |
218 | #endif | |
219 | #ifdef SSL_OP_SINGLE_DH_USE | |
220 | { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, | |
221 | #endif | |
222 | #ifdef SSL_OP_SINGLE_ECDH_USE | |
223 | { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, | |
224 | #endif | |
225 | #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG | |
226 | { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, | |
227 | #endif | |
228 | #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG | |
229 | { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, | |
230 | #endif | |
231 | #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG | |
232 | { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, | |
233 | #endif | |
234 | #ifdef SSL_OP_TLS_D5_BUG | |
235 | { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, | |
236 | #endif | |
237 | #ifdef SSL_OP_TLS_ROLLBACK_BUG | |
238 | { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, | |
239 | #endif | |
240 | }; | |
241 | ||
242 | #ifndef MACRO_PREDEF | |
243 | static int exim_openssl_options_size = nelem(exim_openssl_options); | |
244 | #endif | |
245 | ||
246 | #ifdef MACRO_PREDEF | |
247 | void | |
248 | options_tls(void) | |
249 | { | |
8442641e JH |
250 | uschar buf[64]; |
251 | ||
d7978c0f | 252 | for (struct exim_openssl_option * o = exim_openssl_options; |
8442641e JH |
253 | o < exim_openssl_options + nelem(exim_openssl_options); o++) |
254 | { | |
255 | /* Trailing X is workaround for problem with _OPT_OPENSSL_NO_TLSV1 | |
256 | being a ".ifdef _OPT_OPENSSL_NO_TLSV1_3" match */ | |
257 | ||
258 | spf(buf, sizeof(buf), US"_OPT_OPENSSL_%T_X", o->name); | |
259 | builtin_macro_create(buf); | |
260 | } | |
b10c87b3 JH |
261 | |
262 | # ifdef EXPERIMENTAL_TLS_RESUME | |
263 | builtin_macro_create_var(US"_RESUME_DECODE", RESUME_DECODE_STRING ); | |
264 | # endif | |
e326959e JH |
265 | # ifdef SSL_OP_NO_TLSv1_3 |
266 | builtin_macro_create(US"_HAVE_TLS1_3"); | |
267 | # endif | |
8442641e JH |
268 | } |
269 | #else | |
270 | ||
271 | /******************************************************************************/ | |
272 | ||
059ec3d9 PH |
273 | /* Structure for collecting random data for seeding. */ |
274 | ||
275 | typedef struct randstuff { | |
9e3331ea TK |
276 | struct timeval tv; |
277 | pid_t p; | |
059ec3d9 PH |
278 | } randstuff; |
279 | ||
280 | /* Local static variables */ | |
281 | ||
a2ff477a JH |
282 | static BOOL client_verify_callback_called = FALSE; |
283 | static BOOL server_verify_callback_called = FALSE; | |
059ec3d9 PH |
284 | static const uschar *sid_ctx = US"exim"; |
285 | ||
d4f09789 PP |
286 | /* We have three different contexts to care about. |
287 | ||
288 | Simple case: client, `client_ctx` | |
289 | As a client, we can be doing a callout or cut-through delivery while receiving | |
290 | a message. So we have a client context, which should have options initialised | |
74f1a423 JH |
291 | from the SMTP Transport. We may also concurrently want to make TLS connections |
292 | to utility daemons, so client-contexts are allocated and passed around in call | |
293 | args rather than using a gobal. | |
d4f09789 PP |
294 | |
295 | Server: | |
296 | There are two cases: with and without ServerNameIndication from the client. | |
297 | Given TLS SNI, we can be using different keys, certs and various other | |
298 | configuration settings, because they're re-expanded with $tls_sni set. This | |
299 | allows vhosting with TLS. This SNI is sent in the handshake. | |
300 | A client might not send SNI, so we need a fallback, and an initial setup too. | |
301 | So as a server, we start out using `server_ctx`. | |
302 | If SNI is sent by the client, then we as server, mid-negotiation, try to clone | |
303 | `server_sni` from `server_ctx` and then initialise settings by re-expanding | |
304 | configuration. | |
305 | */ | |
306 | ||
74f1a423 JH |
307 | typedef struct { |
308 | SSL_CTX * ctx; | |
309 | SSL * ssl; | |
c09dbcfb | 310 | gstring * corked; |
74f1a423 JH |
311 | } exim_openssl_client_tls_ctx; |
312 | ||
817d9f57 | 313 | static SSL_CTX *server_ctx = NULL; |
817d9f57 | 314 | static SSL *server_ssl = NULL; |
389ca47a | 315 | |
35731706 | 316 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
817d9f57 | 317 | static SSL_CTX *server_sni = NULL; |
35731706 | 318 | #endif |
059ec3d9 PH |
319 | |
320 | static char ssl_errstring[256]; | |
321 | ||
dea4b568 | 322 | static int ssl_session_timeout = 7200; /* Two hours */ |
a2ff477a JH |
323 | static BOOL client_verify_optional = FALSE; |
324 | static BOOL server_verify_optional = FALSE; | |
059ec3d9 | 325 | |
f5d78688 | 326 | static BOOL reexpand_tls_files_for_sni = FALSE; |
059ec3d9 PH |
327 | |
328 | ||
5b2fd993 JH |
329 | typedef struct ocsp_resp { |
330 | struct ocsp_resp * next; | |
331 | OCSP_RESPONSE * resp; | |
332 | } ocsp_resplist; | |
333 | ||
7be682ca | 334 | typedef struct tls_ext_ctx_cb { |
b10c87b3 | 335 | tls_support * tlsp; |
7be682ca PP |
336 | uschar *certificate; |
337 | uschar *privatekey; | |
f5d78688 | 338 | BOOL is_server; |
a6510420 | 339 | #ifndef DISABLE_OCSP |
c3033f13 | 340 | STACK_OF(X509) *verify_stack; /* chain for verifying the proof */ |
f5d78688 JH |
341 | union { |
342 | struct { | |
343 | uschar *file; | |
5b2fd993 JH |
344 | const uschar *file_expanded; |
345 | ocsp_resplist *olist; | |
f5d78688 JH |
346 | } server; |
347 | struct { | |
44662487 JH |
348 | X509_STORE *verify_store; /* non-null if status requested */ |
349 | BOOL verify_required; | |
f5d78688 JH |
350 | } client; |
351 | } u_ocsp; | |
3f7eeb86 | 352 | #endif |
7be682ca PP |
353 | uschar *dhparam; |
354 | /* these are cached from first expand */ | |
355 | uschar *server_cipher_list; | |
356 | /* only passed down to tls_error: */ | |
357 | host_item *host; | |
55414b25 | 358 | const uschar * verify_cert_hostnames; |
0cbf2b82 | 359 | #ifndef DISABLE_EVENT |
a7538db1 JH |
360 | uschar * event_action; |
361 | #endif | |
7be682ca PP |
362 | } tls_ext_ctx_cb; |
363 | ||
364 | /* should figure out a cleanup of API to handle state preserved per | |
365 | implementation, for various reasons, which can be void * in the APIs. | |
366 | For now, we hack around it. */ | |
b10c87b3 | 367 | tls_ext_ctx_cb *client_static_cbinfo = NULL; /*XXX should not use static; multiple concurrent clients! */ |
817d9f57 | 368 | tls_ext_ctx_cb *server_static_cbinfo = NULL; |
7be682ca PP |
369 | |
370 | static int | |
983207c1 | 371 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
cf0c6164 | 372 | int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr ); |
059ec3d9 | 373 | |
3f7eeb86 | 374 | /* Callbacks */ |
3bcbbbe2 | 375 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
3f7eeb86 | 376 | static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg); |
3bcbbbe2 | 377 | #endif |
f2de3a33 | 378 | #ifndef DISABLE_OCSP |
f5d78688 | 379 | static int tls_server_stapling_cb(SSL *s, void *arg); |
3f7eeb86 PP |
380 | #endif |
381 | ||
059ec3d9 | 382 | |
b10c87b3 | 383 | |
4d93129f | 384 | /* Daemon-called, before every connection, key create/rotate */ |
b10c87b3 JH |
385 | #ifdef EXPERIMENTAL_TLS_RESUME |
386 | static void tk_init(void); | |
387 | static int tls_exdata_idx = -1; | |
388 | #endif | |
389 | ||
390 | void | |
391 | tls_daemon_init(void) | |
392 | { | |
393 | #ifdef EXPERIMENTAL_TLS_RESUME | |
394 | tk_init(); | |
395 | #endif | |
396 | return; | |
397 | } | |
398 | ||
399 | ||
059ec3d9 PH |
400 | /************************************************* |
401 | * Handle TLS error * | |
402 | *************************************************/ | |
403 | ||
404 | /* Called from lots of places when errors occur before actually starting to do | |
405 | the TLS handshake, that is, while the session is still in clear. Always returns | |
406 | DEFER for a server and FAIL for a client so that most calls can use "return | |
407 | tls_error(...)" to do this processing and then give an appropriate return. A | |
408 | single function is used for both server and client, because it is called from | |
409 | some shared functions. | |
410 | ||
411 | Argument: | |
412 | prefix text to include in the logged error | |
413 | host NULL if setting up a server; | |
414 | the connected host if setting up a client | |
7199e1ee | 415 | msg error message or NULL if we should ask OpenSSL |
cf0c6164 | 416 | errstr pointer to output error message |
059ec3d9 PH |
417 | |
418 | Returns: OK/DEFER/FAIL | |
419 | */ | |
420 | ||
421 | static int | |
cf0c6164 | 422 | tls_error(uschar * prefix, const host_item * host, uschar * msg, uschar ** errstr) |
059ec3d9 | 423 | { |
c562fd30 | 424 | if (!msg) |
7199e1ee | 425 | { |
0abc5a13 | 426 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
cf0c6164 | 427 | msg = US ssl_errstring; |
7199e1ee TF |
428 | } |
429 | ||
5a2a0989 JH |
430 | msg = string_sprintf("(%s): %s", prefix, msg); |
431 | DEBUG(D_tls) debug_printf("TLS error '%s'\n", msg); | |
432 | if (errstr) *errstr = msg; | |
cf0c6164 | 433 | return host ? FAIL : DEFER; |
059ec3d9 PH |
434 | } |
435 | ||
436 | ||
437 | ||
438 | /************************************************* | |
439 | * Callback to generate RSA key * | |
440 | *************************************************/ | |
441 | ||
442 | /* | |
443 | Arguments: | |
3ae79556 | 444 | s SSL connection (not used) |
059ec3d9 PH |
445 | export not used |
446 | keylength keylength | |
447 | ||
448 | Returns: pointer to generated key | |
449 | */ | |
450 | ||
451 | static RSA * | |
452 | rsa_callback(SSL *s, int export, int keylength) | |
453 | { | |
454 | RSA *rsa_key; | |
c8dfb21d JH |
455 | #ifdef EXIM_HAVE_RSA_GENKEY_EX |
456 | BIGNUM *bn = BN_new(); | |
457 | #endif | |
458 | ||
059ec3d9 PH |
459 | export = export; /* Shut picky compilers up */ |
460 | DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength); | |
c8dfb21d JH |
461 | |
462 | #ifdef EXIM_HAVE_RSA_GENKEY_EX | |
463 | if ( !BN_set_word(bn, (unsigned long)RSA_F4) | |
f2cb6292 | 464 | || !(rsa_key = RSA_new()) |
c8dfb21d JH |
465 | || !RSA_generate_key_ex(rsa_key, keylength, bn, NULL) |
466 | ) | |
467 | #else | |
23bb6982 | 468 | if (!(rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL))) |
c8dfb21d JH |
469 | #endif |
470 | ||
059ec3d9 | 471 | { |
0abc5a13 | 472 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
059ec3d9 PH |
473 | log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s", |
474 | ssl_errstring); | |
475 | return NULL; | |
476 | } | |
477 | return rsa_key; | |
478 | } | |
479 | ||
480 | ||
481 | ||
f5d78688 | 482 | /* Extreme debug |
f2de3a33 | 483 | #ifndef DISABLE_OCSP |
f5d78688 JH |
484 | void |
485 | x509_store_dump_cert_s_names(X509_STORE * store) | |
486 | { | |
487 | STACK_OF(X509_OBJECT) * roots= store->objs; | |
f5d78688 JH |
488 | static uschar name[256]; |
489 | ||
d7978c0f | 490 | for (int i= 0; i < sk_X509_OBJECT_num(roots); i++) |
f5d78688 JH |
491 | { |
492 | X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i); | |
493 | if(tmp_obj->type == X509_LU_X509) | |
494 | { | |
70e384dd JH |
495 | X509_NAME * sn = X509_get_subject_name(tmp_obj->data.x509); |
496 | if (X509_NAME_oneline(sn, CS name, sizeof(name))) | |
497 | { | |
498 | name[sizeof(name)-1] = '\0'; | |
499 | debug_printf(" %s\n", name); | |
500 | } | |
f5d78688 JH |
501 | } |
502 | } | |
503 | } | |
504 | #endif | |
505 | */ | |
506 | ||
059ec3d9 | 507 | |
0cbf2b82 | 508 | #ifndef DISABLE_EVENT |
f69979cf JH |
509 | static int |
510 | verify_event(tls_support * tlsp, X509 * cert, int depth, const uschar * dn, | |
511 | BOOL *calledp, const BOOL *optionalp, const uschar * what) | |
512 | { | |
513 | uschar * ev; | |
514 | uschar * yield; | |
515 | X509 * old_cert; | |
516 | ||
517 | ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action; | |
518 | if (ev) | |
519 | { | |
aaba7d03 | 520 | DEBUG(D_tls) debug_printf("verify_event: %s %d\n", what, depth); |
f69979cf JH |
521 | old_cert = tlsp->peercert; |
522 | tlsp->peercert = X509_dup(cert); | |
523 | /* NB we do not bother setting peerdn */ | |
524 | if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth)))) | |
525 | { | |
526 | log_write(0, LOG_MAIN, "[%s] %s verify denied by event-action: " | |
527 | "depth=%d cert=%s: %s", | |
528 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
529 | what, depth, dn, yield); | |
530 | *calledp = TRUE; | |
531 | if (!*optionalp) | |
532 | { | |
533 | if (old_cert) tlsp->peercert = old_cert; /* restore 1st failing cert */ | |
534 | return 1; /* reject (leaving peercert set) */ | |
535 | } | |
536 | DEBUG(D_tls) debug_printf("Event-action verify failure overridden " | |
537 | "(host in tls_try_verify_hosts)\n"); | |
4a1bd6b9 | 538 | tlsp->verify_override = TRUE; |
f69979cf JH |
539 | } |
540 | X509_free(tlsp->peercert); | |
541 | tlsp->peercert = old_cert; | |
542 | } | |
543 | return 0; | |
544 | } | |
545 | #endif | |
546 | ||
059ec3d9 PH |
547 | /************************************************* |
548 | * Callback for verification * | |
549 | *************************************************/ | |
550 | ||
551 | /* The SSL library does certificate verification if set up to do so. This | |
552 | callback has the current yes/no state is in "state". If verification succeeded, | |
f69979cf JH |
553 | we set the certificate-verified flag. If verification failed, what happens |
554 | depends on whether the client is required to present a verifiable certificate | |
555 | or not. | |
059ec3d9 PH |
556 | |
557 | If verification is optional, we change the state to yes, but still log the | |
558 | verification error. For some reason (it really would help to have proper | |
559 | documentation of OpenSSL), this callback function then gets called again, this | |
f69979cf JH |
560 | time with state = 1. We must take care not to set the private verified flag on |
561 | the second time through. | |
059ec3d9 PH |
562 | |
563 | Note: this function is not called if the client fails to present a certificate | |
564 | when asked. We get here only if a certificate has been received. Handling of | |
565 | optional verification for this case is done when requesting SSL to verify, by | |
566 | setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case. | |
567 | ||
a7538db1 JH |
568 | May be called multiple times for different issues with a certificate, even |
569 | for a given "depth" in the certificate chain. | |
570 | ||
059ec3d9 | 571 | Arguments: |
f2f2c91b JH |
572 | preverify_ok current yes/no state as 1/0 |
573 | x509ctx certificate information. | |
574 | tlsp per-direction (client vs. server) support data | |
575 | calledp has-been-called flag | |
576 | optionalp verification-is-optional flag | |
059ec3d9 | 577 | |
f2f2c91b | 578 | Returns: 0 if verification should fail, otherwise 1 |
059ec3d9 PH |
579 | */ |
580 | ||
581 | static int | |
70e384dd JH |
582 | verify_callback(int preverify_ok, X509_STORE_CTX * x509ctx, |
583 | tls_support * tlsp, BOOL * calledp, BOOL * optionalp) | |
059ec3d9 | 584 | { |
421aff85 | 585 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); |
a7538db1 | 586 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
f69979cf | 587 | uschar dn[256]; |
059ec3d9 | 588 | |
70e384dd JH |
589 | if (!X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn))) |
590 | { | |
591 | DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); | |
592 | log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", | |
593 | tlsp == &tls_out ? deliver_host_address : sender_host_address); | |
594 | return 0; | |
595 | } | |
f69979cf | 596 | dn[sizeof(dn)-1] = '\0'; |
059ec3d9 | 597 | |
f4e62a87 | 598 | tlsp->verify_override = FALSE; |
f2f2c91b | 599 | if (preverify_ok == 0) |
059ec3d9 | 600 | { |
f77197ae JH |
601 | uschar * extra = verify_mode ? string_sprintf(" (during %c-verify for [%s])", |
602 | *verify_mode, sender_host_address) | |
603 | : US""; | |
604 | log_write(0, LOG_MAIN, "[%s] SSL verify error%s: depth=%d error=%s cert=%s", | |
605 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
606 | extra, depth, | |
607 | X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), dn); | |
a2ff477a | 608 | *calledp = TRUE; |
9d1c15ef JH |
609 | if (!*optionalp) |
610 | { | |
f69979cf JH |
611 | if (!tlsp->peercert) |
612 | tlsp->peercert = X509_dup(cert); /* record failing cert */ | |
613 | return 0; /* reject */ | |
9d1c15ef | 614 | } |
059ec3d9 PH |
615 | DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " |
616 | "tls_try_verify_hosts)\n"); | |
4a1bd6b9 | 617 | tlsp->verify_override = TRUE; |
059ec3d9 PH |
618 | } |
619 | ||
a7538db1 | 620 | else if (depth != 0) |
059ec3d9 | 621 | { |
f69979cf | 622 | DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, dn); |
f2de3a33 | 623 | #ifndef DISABLE_OCSP |
f5d78688 JH |
624 | if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store) |
625 | { /* client, wanting stapling */ | |
626 | /* Add the server cert's signing chain as the one | |
627 | for the verification of the OCSP stapled information. */ | |
94431adb | 628 | |
f5d78688 | 629 | if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, |
421aff85 | 630 | cert)) |
f5d78688 | 631 | ERR_clear_error(); |
c3033f13 | 632 | sk_X509_push(client_static_cbinfo->verify_stack, cert); |
f5d78688 | 633 | } |
a7538db1 | 634 | #endif |
0cbf2b82 | 635 | #ifndef DISABLE_EVENT |
f69979cf JH |
636 | if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) |
637 | return 0; /* reject, with peercert set */ | |
f5d78688 | 638 | #endif |
059ec3d9 PH |
639 | } |
640 | else | |
641 | { | |
55414b25 | 642 | const uschar * verify_cert_hostnames; |
e51c7be2 | 643 | |
e51c7be2 JH |
644 | if ( tlsp == &tls_out |
645 | && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames))) | |
afdb5e9c | 646 | /* client, wanting hostname check */ |
e51c7be2 | 647 | { |
f69979cf | 648 | |
740f36d4 | 649 | #ifdef EXIM_HAVE_OPENSSL_CHECKHOST |
f69979cf JH |
650 | # ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
651 | # define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0 | |
652 | # endif | |
653 | # ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS | |
654 | # define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0 | |
655 | # endif | |
e51c7be2 | 656 | int sep = 0; |
55414b25 | 657 | const uschar * list = verify_cert_hostnames; |
e51c7be2 | 658 | uschar * name; |
d8e7834a JH |
659 | int rc; |
660 | while ((name = string_nextinlist(&list, &sep, NULL, 0))) | |
f40d5be3 | 661 | if ((rc = X509_check_host(cert, CCS name, 0, |
8d692470 | 662 | X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS |
740f36d4 JH |
663 | | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS, |
664 | NULL))) | |
d8e7834a JH |
665 | { |
666 | if (rc < 0) | |
667 | { | |
93a6fce2 | 668 | log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", |
f77197ae | 669 | tlsp == &tls_out ? deliver_host_address : sender_host_address); |
d8e7834a JH |
670 | name = NULL; |
671 | } | |
e51c7be2 | 672 | break; |
d8e7834a | 673 | } |
e51c7be2 | 674 | if (!name) |
f69979cf | 675 | #else |
e51c7be2 | 676 | if (!tls_is_name_for_cert(verify_cert_hostnames, cert)) |
f69979cf | 677 | #endif |
e51c7be2 | 678 | { |
f77197ae JH |
679 | uschar * extra = verify_mode |
680 | ? string_sprintf(" (during %c-verify for [%s])", | |
681 | *verify_mode, sender_host_address) | |
682 | : US""; | |
e51c7be2 | 683 | log_write(0, LOG_MAIN, |
f77197ae JH |
684 | "[%s] SSL verify error%s: certificate name mismatch: DN=\"%s\" H=\"%s\"", |
685 | tlsp == &tls_out ? deliver_host_address : sender_host_address, | |
686 | extra, dn, verify_cert_hostnames); | |
a3ef7310 JH |
687 | *calledp = TRUE; |
688 | if (!*optionalp) | |
f69979cf JH |
689 | { |
690 | if (!tlsp->peercert) | |
691 | tlsp->peercert = X509_dup(cert); /* record failing cert */ | |
692 | return 0; /* reject */ | |
693 | } | |
4a1bd6b9 | 694 | DEBUG(D_tls) debug_printf("SSL verify name failure overridden (host in " |
a3ef7310 | 695 | "tls_try_verify_hosts)\n"); |
4a1bd6b9 | 696 | tlsp->verify_override = TRUE; |
e51c7be2 | 697 | } |
f69979cf | 698 | } |
e51c7be2 | 699 | |
0cbf2b82 | 700 | #ifndef DISABLE_EVENT |
f69979cf JH |
701 | if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) |
702 | return 0; /* reject, with peercert set */ | |
e51c7be2 JH |
703 | #endif |
704 | ||
93dcb1c2 | 705 | DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n", |
f69979cf | 706 | *calledp ? "" : " authenticated", dn); |
93dcb1c2 | 707 | *calledp = TRUE; |
059ec3d9 PH |
708 | } |
709 | ||
a7538db1 | 710 | return 1; /* accept, at least for this level */ |
059ec3d9 PH |
711 | } |
712 | ||
a2ff477a | 713 | static int |
f2f2c91b | 714 | verify_callback_client(int preverify_ok, X509_STORE_CTX *x509ctx) |
a2ff477a | 715 | { |
f2f2c91b JH |
716 | return verify_callback(preverify_ok, x509ctx, &tls_out, |
717 | &client_verify_callback_called, &client_verify_optional); | |
a2ff477a JH |
718 | } |
719 | ||
720 | static int | |
f2f2c91b | 721 | verify_callback_server(int preverify_ok, X509_STORE_CTX *x509ctx) |
a2ff477a | 722 | { |
f2f2c91b JH |
723 | return verify_callback(preverify_ok, x509ctx, &tls_in, |
724 | &server_verify_callback_called, &server_verify_optional); | |
a2ff477a JH |
725 | } |
726 | ||
059ec3d9 | 727 | |
c0635b6d | 728 | #ifdef SUPPORT_DANE |
53a7196b | 729 | |
e5cccda9 JH |
730 | /* This gets called *by* the dane library verify callback, which interposes |
731 | itself. | |
732 | */ | |
733 | static int | |
f2f2c91b | 734 | verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx) |
e5cccda9 JH |
735 | { |
736 | X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); | |
f69979cf | 737 | uschar dn[256]; |
83b27293 | 738 | int depth = X509_STORE_CTX_get_error_depth(x509ctx); |
5c75db2e | 739 | #ifndef DISABLE_EVENT |
f69979cf | 740 | BOOL dummy_called, optional = FALSE; |
83b27293 | 741 | #endif |
e5cccda9 | 742 | |
70e384dd JH |
743 | if (!X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn))) |
744 | { | |
745 | DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); | |
746 | log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", | |
747 | deliver_host_address); | |
748 | return 0; | |
749 | } | |
f69979cf | 750 | dn[sizeof(dn)-1] = '\0'; |
e5cccda9 | 751 | |
f2f2c91b JH |
752 | DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n", |
753 | preverify_ok ? "ok":"BAD", depth, dn); | |
e5cccda9 | 754 | |
0cbf2b82 | 755 | #ifndef DISABLE_EVENT |
f69979cf JH |
756 | if (verify_event(&tls_out, cert, depth, dn, |
757 | &dummy_called, &optional, US"DANE")) | |
758 | return 0; /* reject, with peercert set */ | |
83b27293 JH |
759 | #endif |
760 | ||
f2f2c91b | 761 | if (preverify_ok == 1) |
6fbf3599 | 762 | { |
4a1bd6b9 | 763 | tls_out.dane_verified = TRUE; |
6fbf3599 JH |
764 | #ifndef DISABLE_OCSP |
765 | if (client_static_cbinfo->u_ocsp.client.verify_store) | |
766 | { /* client, wanting stapling */ | |
767 | /* Add the server cert's signing chain as the one | |
768 | for the verification of the OCSP stapled information. */ | |
769 | ||
770 | if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, | |
771 | cert)) | |
772 | ERR_clear_error(); | |
773 | sk_X509_push(client_static_cbinfo->verify_stack, cert); | |
774 | } | |
775 | #endif | |
776 | } | |
f2f2c91b JH |
777 | else |
778 | { | |
779 | int err = X509_STORE_CTX_get_error(x509ctx); | |
780 | DEBUG(D_tls) | |
781 | debug_printf(" - err %d '%s'\n", err, X509_verify_cert_error_string(err)); | |
3c51463e | 782 | if (err == X509_V_ERR_APPLICATION_VERIFICATION) |
f2f2c91b JH |
783 | preverify_ok = 1; |
784 | } | |
785 | return preverify_ok; | |
e5cccda9 | 786 | } |
53a7196b | 787 | |
c0635b6d | 788 | #endif /*SUPPORT_DANE*/ |
e5cccda9 | 789 | |
059ec3d9 PH |
790 | |
791 | /************************************************* | |
792 | * Information callback * | |
793 | *************************************************/ | |
794 | ||
795 | /* The SSL library functions call this from time to time to indicate what they | |
7be682ca PP |
796 | are doing. We copy the string to the debugging output when TLS debugging has |
797 | been requested. | |
059ec3d9 PH |
798 | |
799 | Arguments: | |
800 | s the SSL connection | |
801 | where | |
802 | ret | |
803 | ||
804 | Returns: nothing | |
805 | */ | |
806 | ||
807 | static void | |
808 | info_callback(SSL *s, int where, int ret) | |
809 | { | |
0abc5a13 JH |
810 | DEBUG(D_tls) |
811 | { | |
812 | const uschar * str; | |
813 | ||
814 | if (where & SSL_ST_CONNECT) | |
48224640 | 815 | str = US"SSL_connect"; |
0abc5a13 | 816 | else if (where & SSL_ST_ACCEPT) |
48224640 | 817 | str = US"SSL_accept"; |
0abc5a13 | 818 | else |
48224640 | 819 | str = US"SSL info (undefined)"; |
0abc5a13 JH |
820 | |
821 | if (where & SSL_CB_LOOP) | |
822 | debug_printf("%s: %s\n", str, SSL_state_string_long(s)); | |
823 | else if (where & SSL_CB_ALERT) | |
824 | debug_printf("SSL3 alert %s:%s:%s\n", | |
48224640 | 825 | str = where & SSL_CB_READ ? US"read" : US"write", |
0abc5a13 JH |
826 | SSL_alert_type_string_long(ret), SSL_alert_desc_string_long(ret)); |
827 | else if (where & SSL_CB_EXIT) | |
828 | if (ret == 0) | |
829 | debug_printf("%s: failed in %s\n", str, SSL_state_string_long(s)); | |
830 | else if (ret < 0) | |
831 | debug_printf("%s: error in %s\n", str, SSL_state_string_long(s)); | |
832 | else if (where & SSL_CB_HANDSHAKE_START) | |
833 | debug_printf("%s: hshake start: %s\n", str, SSL_state_string_long(s)); | |
834 | else if (where & SSL_CB_HANDSHAKE_DONE) | |
835 | debug_printf("%s: hshake done: %s\n", str, SSL_state_string_long(s)); | |
836 | } | |
059ec3d9 PH |
837 | } |
838 | ||
8238bc7b | 839 | #ifdef OPENSSL_HAVE_KEYLOG_CB |
8a40db1c JH |
840 | static void |
841 | keylog_callback(const SSL *ssl, const char *line) | |
842 | { | |
843 | DEBUG(D_tls) debug_printf("%.200s\n", line); | |
844 | } | |
8238bc7b | 845 | #endif |
8a40db1c | 846 | |
059ec3d9 | 847 | |
b10c87b3 JH |
848 | #ifdef EXPERIMENTAL_TLS_RESUME |
849 | /* Manage the keysets used for encrypting the session tickets, on the server. */ | |
850 | ||
851 | typedef struct { /* Session ticket encryption key */ | |
852 | uschar name[16]; | |
853 | ||
854 | const EVP_CIPHER * aes_cipher; | |
4d93129f | 855 | uschar aes_key[32]; /* size needed depends on cipher. aes_128 implies 128/8 = 16? */ |
b10c87b3 JH |
856 | const EVP_MD * hmac_hash; |
857 | uschar hmac_key[16]; | |
858 | time_t renew; | |
859 | time_t expire; | |
860 | } exim_stek; | |
861 | ||
4d93129f JH |
862 | static exim_stek exim_tk; /* current key */ |
863 | static exim_stek exim_tk_old; /* previous key */ | |
b10c87b3 JH |
864 | |
865 | static void | |
866 | tk_init(void) | |
867 | { | |
4d93129f JH |
868 | time_t t = time(NULL); |
869 | ||
b10c87b3 JH |
870 | if (exim_tk.name[0]) |
871 | { | |
4d93129f | 872 | if (exim_tk.renew >= t) return; |
b10c87b3 JH |
873 | exim_tk_old = exim_tk; |
874 | } | |
875 | ||
876 | if (f.running_in_test_harness) ssl_session_timeout = 6; | |
877 | ||
878 | DEBUG(D_tls) debug_printf("OpenSSL: %s STEK\n", exim_tk.name[0] ? "rotating" : "creating"); | |
879 | if (RAND_bytes(exim_tk.aes_key, sizeof(exim_tk.aes_key)) <= 0) return; | |
880 | if (RAND_bytes(exim_tk.hmac_key, sizeof(exim_tk.hmac_key)) <= 0) return; | |
881 | if (RAND_bytes(exim_tk.name+1, sizeof(exim_tk.name)-1) <= 0) return; | |
882 | ||
883 | exim_tk.name[0] = 'E'; | |
4d93129f | 884 | exim_tk.aes_cipher = EVP_aes_256_cbc(); |
b10c87b3 | 885 | exim_tk.hmac_hash = EVP_sha256(); |
4d93129f JH |
886 | exim_tk.expire = t + ssl_session_timeout; |
887 | exim_tk.renew = t + ssl_session_timeout/2; | |
b10c87b3 JH |
888 | } |
889 | ||
890 | static exim_stek * | |
891 | tk_current(void) | |
892 | { | |
893 | if (!exim_tk.name[0]) return NULL; | |
894 | return &exim_tk; | |
895 | } | |
896 | ||
897 | static exim_stek * | |
898 | tk_find(const uschar * name) | |
899 | { | |
900 | return memcmp(name, exim_tk.name, sizeof(exim_tk.name)) == 0 ? &exim_tk | |
901 | : memcmp(name, exim_tk_old.name, sizeof(exim_tk_old.name)) == 0 ? &exim_tk_old | |
902 | : NULL; | |
903 | } | |
904 | ||
905 | /* Callback for session tickets, on server */ | |
906 | static int | |
907 | ticket_key_callback(SSL * ssl, uschar key_name[16], | |
908 | uschar * iv, EVP_CIPHER_CTX * ctx, HMAC_CTX * hctx, int enc) | |
909 | { | |
910 | tls_support * tlsp = server_static_cbinfo->tlsp; | |
911 | exim_stek * key; | |
912 | ||
913 | if (enc) | |
914 | { | |
915 | DEBUG(D_tls) debug_printf("ticket_key_callback: create new session\n"); | |
916 | tlsp->resumption |= RESUME_CLIENT_REQUESTED; | |
917 | ||
918 | if (RAND_bytes(iv, EVP_MAX_IV_LENGTH) <= 0) | |
919 | return -1; /* insufficient random */ | |
920 | ||
921 | if (!(key = tk_current())) /* current key doesn't exist or isn't valid */ | |
922 | return 0; /* key couldn't be created */ | |
923 | memcpy(key_name, key->name, 16); | |
d70fc283 | 924 | DEBUG(D_tls) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - time(NULL)); |
b10c87b3 JH |
925 | |
926 | /*XXX will want these dependent on the ssl session strength */ | |
927 | HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key), | |
928 | key->hmac_hash, NULL); | |
929 | EVP_EncryptInit_ex(ctx, key->aes_cipher, NULL, key->aes_key, iv); | |
930 | ||
931 | DEBUG(D_tls) debug_printf("ticket created\n"); | |
932 | return 1; | |
933 | } | |
934 | else | |
935 | { | |
936 | time_t now = time(NULL); | |
937 | ||
938 | DEBUG(D_tls) debug_printf("ticket_key_callback: retrieve session\n"); | |
939 | tlsp->resumption |= RESUME_CLIENT_SUGGESTED; | |
940 | ||
941 | if (!(key = tk_find(key_name)) || key->expire < now) | |
942 | { | |
943 | DEBUG(D_tls) | |
944 | { | |
945 | debug_printf("ticket not usable (%s)\n", key ? "expired" : "not found"); | |
d70fc283 | 946 | if (key) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - now); |
b10c87b3 JH |
947 | } |
948 | return 0; | |
949 | } | |
950 | ||
951 | HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key), | |
952 | key->hmac_hash, NULL); | |
953 | EVP_DecryptInit_ex(ctx, key->aes_cipher, NULL, key->aes_key, iv); | |
954 | ||
d70fc283 | 955 | DEBUG(D_tls) debug_printf("ticket usable, STEK expire " TIME_T_FMT "\n", key->expire - now); |
dea4b568 JH |
956 | |
957 | /* The ticket lifetime and renewal are the same as the STEK lifetime and | |
958 | renewal, which is overenthusiastic. A factor of, say, 3x longer STEK would | |
959 | be better. To do that we'd have to encode ticket lifetime in the name as | |
960 | we don't yet see the restored session. Could check posthandshake for TLS1.3 | |
961 | and trigger a new ticket then, but cannot do that for TLS1.2 */ | |
b10c87b3 JH |
962 | return key->renew < now ? 2 : 1; |
963 | } | |
964 | } | |
965 | #endif | |
966 | ||
967 | ||
059ec3d9 PH |
968 | |
969 | /************************************************* | |
970 | * Initialize for DH * | |
971 | *************************************************/ | |
972 | ||
973 | /* If dhparam is set, expand it, and load up the parameters for DH encryption. | |
974 | ||
975 | Arguments: | |
038597d2 | 976 | sctx The current SSL CTX (inbound or outbound) |
a799883d | 977 | dhparam DH parameter file or fixed parameter identity string |
7199e1ee | 978 | host connected host, if client; NULL if server |
cf0c6164 | 979 | errstr error string pointer |
059ec3d9 PH |
980 | |
981 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
982 | */ | |
983 | ||
984 | static BOOL | |
cf0c6164 | 985 | init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host, uschar ** errstr) |
059ec3d9 | 986 | { |
059ec3d9 PH |
987 | BIO *bio; |
988 | DH *dh; | |
989 | uschar *dhexpanded; | |
a799883d | 990 | const char *pem; |
6600985a | 991 | int dh_bitsize; |
059ec3d9 | 992 | |
cf0c6164 | 993 | if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded, errstr)) |
059ec3d9 PH |
994 | return FALSE; |
995 | ||
0df4ab80 | 996 | if (!dhexpanded || !*dhexpanded) |
a799883d | 997 | bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1); |
a799883d | 998 | else if (dhexpanded[0] == '/') |
059ec3d9 | 999 | { |
0df4ab80 | 1000 | if (!(bio = BIO_new_file(CS dhexpanded, "r"))) |
059ec3d9 | 1001 | { |
7199e1ee | 1002 | tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), |
cf0c6164 | 1003 | host, US strerror(errno), errstr); |
a799883d | 1004 | return FALSE; |
059ec3d9 | 1005 | } |
a799883d PP |
1006 | } |
1007 | else | |
1008 | { | |
1009 | if (Ustrcmp(dhexpanded, "none") == 0) | |
059ec3d9 | 1010 | { |
a799883d PP |
1011 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); |
1012 | return TRUE; | |
059ec3d9 | 1013 | } |
a799883d | 1014 | |
0df4ab80 | 1015 | if (!(pem = std_dh_prime_named(dhexpanded))) |
a799883d PP |
1016 | { |
1017 | tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded), | |
cf0c6164 | 1018 | host, US strerror(errno), errstr); |
a799883d PP |
1019 | return FALSE; |
1020 | } | |
1021 | bio = BIO_new_mem_buf(CS pem, -1); | |
1022 | } | |
1023 | ||
0df4ab80 | 1024 | if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL))) |
a799883d | 1025 | { |
059ec3d9 | 1026 | BIO_free(bio); |
a799883d | 1027 | tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded), |
cf0c6164 | 1028 | host, NULL, errstr); |
a799883d PP |
1029 | return FALSE; |
1030 | } | |
1031 | ||
6600985a PP |
1032 | /* note: our default limit of 2236 is not a multiple of 8; the limit comes from |
1033 | * an NSS limit, and the GnuTLS APIs handle bit-sizes fine, so we went with | |
1034 | * 2236. But older OpenSSL can only report in bytes (octets), not bits. | |
1035 | * If someone wants to dance at the edge, then they can raise the limit or use | |
1036 | * current libraries. */ | |
1037 | #ifdef EXIM_HAVE_OPENSSL_DH_BITS | |
1038 | /* Added in commit 26c79d5641d; `git describe --contains` says OpenSSL_1_1_0-pre1~1022 | |
1039 | * This predates OpenSSL_1_1_0 (before a, b, ...) so is in all 1.1.0 */ | |
1040 | dh_bitsize = DH_bits(dh); | |
1041 | #else | |
1042 | dh_bitsize = 8 * DH_size(dh); | |
1043 | #endif | |
1044 | ||
a799883d PP |
1045 | /* Even if it is larger, we silently return success rather than cause things |
1046 | * to fail out, so that a too-large DH will not knock out all TLS; it's a | |
1047 | * debatable choice. */ | |
6600985a | 1048 | if (dh_bitsize > tls_dh_max_bits) |
a799883d PP |
1049 | { |
1050 | DEBUG(D_tls) | |
170f4904 | 1051 | debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d\n", |
6600985a | 1052 | dh_bitsize, tls_dh_max_bits); |
a799883d PP |
1053 | } |
1054 | else | |
1055 | { | |
1056 | SSL_CTX_set_tmp_dh(sctx, dh); | |
1057 | DEBUG(D_tls) | |
1058 | debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n", | |
6600985a | 1059 | dhexpanded ? dhexpanded : US"default", dh_bitsize); |
059ec3d9 PH |
1060 | } |
1061 | ||
a799883d PP |
1062 | DH_free(dh); |
1063 | BIO_free(bio); | |
1064 | ||
1065 | return TRUE; | |
059ec3d9 PH |
1066 | } |
1067 | ||
1068 | ||
1069 | ||
1070 | ||
038597d2 PP |
1071 | /************************************************* |
1072 | * Initialize for ECDH * | |
1073 | *************************************************/ | |
1074 | ||
1075 | /* Load parameters for ECDH encryption. | |
1076 | ||
1077 | For now, we stick to NIST P-256 because: it's simple and easy to configure; | |
1078 | it avoids any patent issues that might bite redistributors; despite events in | |
1079 | the news and concerns over curve choices, we're not cryptographers, we're not | |
1080 | pretending to be, and this is "good enough" to be better than no support, | |
1081 | protecting against most adversaries. Given another year or two, there might | |
1082 | be sufficient clarity about a "right" way forward to let us make an informed | |
1083 | decision, instead of a knee-jerk reaction. | |
1084 | ||
1085 | Longer-term, we should look at supporting both various named curves and | |
1086 | external files generated with "openssl ecparam", much as we do for init_dh(). | |
1087 | We should also support "none" as a value, to explicitly avoid initialisation. | |
1088 | ||
1089 | Patches welcome. | |
1090 | ||
1091 | Arguments: | |
1092 | sctx The current SSL CTX (inbound or outbound) | |
1093 | host connected host, if client; NULL if server | |
cf0c6164 | 1094 | errstr error string pointer |
038597d2 PP |
1095 | |
1096 | Returns: TRUE if OK (nothing to set up, or setup worked) | |
1097 | */ | |
1098 | ||
1099 | static BOOL | |
cf0c6164 | 1100 | init_ecdh(SSL_CTX * sctx, host_item * host, uschar ** errstr) |
038597d2 | 1101 | { |
63f0dbe0 JH |
1102 | #ifdef OPENSSL_NO_ECDH |
1103 | return TRUE; | |
1104 | #else | |
1105 | ||
10ca4f1c JH |
1106 | EC_KEY * ecdh; |
1107 | uschar * exp_curve; | |
1108 | int nid; | |
1109 | BOOL rv; | |
1110 | ||
038597d2 PP |
1111 | if (host) /* No ECDH setup for clients, only for servers */ |
1112 | return TRUE; | |
1113 | ||
10ca4f1c | 1114 | # ifndef EXIM_HAVE_ECDH |
038597d2 PP |
1115 | DEBUG(D_tls) |
1116 | debug_printf("No OpenSSL API to define ECDH parameters, skipping\n"); | |
1117 | return TRUE; | |
038597d2 | 1118 | # else |
10ca4f1c | 1119 | |
cf0c6164 | 1120 | if (!expand_check(tls_eccurve, US"tls_eccurve", &exp_curve, errstr)) |
10ca4f1c JH |
1121 | return FALSE; |
1122 | if (!exp_curve || !*exp_curve) | |
1123 | return TRUE; | |
1124 | ||
8e53a4fc | 1125 | /* "auto" needs to be handled carefully. |
4c04137d | 1126 | * OpenSSL < 1.0.2: we do not select anything, but fallback to prime256v1 |
8e53a4fc | 1127 | * OpenSSL < 1.1.0: we have to call SSL_CTX_set_ecdh_auto |
4c04137d | 1128 | * (openssl/ssl.h defines SSL_CTRL_SET_ECDH_AUTO) |
8e53a4fc HSHR |
1129 | * OpenSSL >= 1.1.0: we do not set anything, the libray does autoselection |
1130 | * https://github.com/openssl/openssl/commit/fe6ef2472db933f01b59cad82aa925736935984b | |
1131 | */ | |
10ca4f1c | 1132 | if (Ustrcmp(exp_curve, "auto") == 0) |
038597d2 | 1133 | { |
8e53a4fc | 1134 | #if OPENSSL_VERSION_NUMBER < 0x10002000L |
10ca4f1c | 1135 | DEBUG(D_tls) debug_printf( |
8e53a4fc | 1136 | "ECDH OpenSSL < 1.0.2: temp key parameter settings: overriding \"auto\" with \"prime256v1\"\n"); |
78a3bbd5 | 1137 | exp_curve = US"prime256v1"; |
8e53a4fc HSHR |
1138 | #else |
1139 | # if defined SSL_CTRL_SET_ECDH_AUTO | |
1140 | DEBUG(D_tls) debug_printf( | |
1141 | "ECDH OpenSSL 1.0.2+ temp key parameter settings: autoselection\n"); | |
10ca4f1c JH |
1142 | SSL_CTX_set_ecdh_auto(sctx, 1); |
1143 | return TRUE; | |
8e53a4fc HSHR |
1144 | # else |
1145 | DEBUG(D_tls) debug_printf( | |
1146 | "ECDH OpenSSL 1.1.0+ temp key parameter settings: default selection\n"); | |
1147 | return TRUE; | |
1148 | # endif | |
1149 | #endif | |
10ca4f1c | 1150 | } |
038597d2 | 1151 | |
10ca4f1c JH |
1152 | DEBUG(D_tls) debug_printf("ECDH: curve '%s'\n", exp_curve); |
1153 | if ( (nid = OBJ_sn2nid (CCS exp_curve)) == NID_undef | |
1154 | # ifdef EXIM_HAVE_OPENSSL_EC_NIST2NID | |
1155 | && (nid = EC_curve_nist2nid(CCS exp_curve)) == NID_undef | |
1156 | # endif | |
1157 | ) | |
1158 | { | |
cf0c6164 JH |
1159 | tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", exp_curve), |
1160 | host, NULL, errstr); | |
10ca4f1c JH |
1161 | return FALSE; |
1162 | } | |
038597d2 | 1163 | |
10ca4f1c JH |
1164 | if (!(ecdh = EC_KEY_new_by_curve_name(nid))) |
1165 | { | |
cf0c6164 | 1166 | tls_error(US"Unable to create ec curve", host, NULL, errstr); |
10ca4f1c | 1167 | return FALSE; |
038597d2 | 1168 | } |
10ca4f1c JH |
1169 | |
1170 | /* The "tmp" in the name here refers to setting a temporary key | |
1171 | not to the stability of the interface. */ | |
1172 | ||
1173 | if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0)) | |
cf0c6164 | 1174 | tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), host, NULL, errstr); |
10ca4f1c JH |
1175 | else |
1176 | DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve); | |
1177 | ||
1178 | EC_KEY_free(ecdh); | |
1179 | return !rv; | |
1180 | ||
1181 | # endif /*EXIM_HAVE_ECDH*/ | |
1182 | #endif /*OPENSSL_NO_ECDH*/ | |
038597d2 PP |
1183 | } |
1184 | ||
1185 | ||
1186 | ||
1187 | ||
f2de3a33 | 1188 | #ifndef DISABLE_OCSP |
3f7eeb86 PP |
1189 | /************************************************* |
1190 | * Load OCSP information into state * | |
1191 | *************************************************/ | |
f5d78688 | 1192 | /* Called to load the server OCSP response from the given file into memory, once |
3f7eeb86 PP |
1193 | caller has determined this is needed. Checks validity. Debugs a message |
1194 | if invalid. | |
1195 | ||
1196 | ASSUMES: single response, for single cert. | |
1197 | ||
1198 | Arguments: | |
1199 | sctx the SSL_CTX* to update | |
1200 | cbinfo various parts of session state | |
5b2fd993 | 1201 | filename the filename putatively holding an OCSP response |
3f7eeb86 PP |
1202 | |
1203 | */ | |
1204 | ||
1205 | static void | |
5b2fd993 JH |
1206 | ocsp_load_response(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, |
1207 | const uschar * filename) | |
3f7eeb86 | 1208 | { |
ee5b1e28 JH |
1209 | BIO * bio; |
1210 | OCSP_RESPONSE * resp; | |
1211 | OCSP_BASICRESP * basic_response; | |
1212 | OCSP_SINGLERESP * single_response; | |
1213 | ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd; | |
ee5b1e28 | 1214 | STACK_OF(X509) * sk; |
3f7eeb86 PP |
1215 | unsigned long verify_flags; |
1216 | int status, reason, i; | |
1217 | ||
5b2fd993 | 1218 | DEBUG(D_tls) debug_printf("tls_ocsp_file '%s'\n", filename); |
3f7eeb86 | 1219 | |
5b2fd993 | 1220 | if (!(bio = BIO_new_file(CS filename, "rb"))) |
3f7eeb86 PP |
1221 | { |
1222 | DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", | |
5b2fd993 | 1223 | filename); |
3f7eeb86 PP |
1224 | return; |
1225 | } | |
1226 | ||
1227 | resp = d2i_OCSP_RESPONSE_bio(bio, NULL); | |
1228 | BIO_free(bio); | |
1229 | if (!resp) | |
1230 | { | |
1231 | DEBUG(D_tls) debug_printf("Error reading OCSP response.\n"); | |
1232 | return; | |
1233 | } | |
1234 | ||
ee5b1e28 | 1235 | if ((status = OCSP_response_status(resp)) != OCSP_RESPONSE_STATUS_SUCCESSFUL) |
3f7eeb86 PP |
1236 | { |
1237 | DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", | |
1238 | OCSP_response_status_str(status), status); | |
f5d78688 | 1239 | goto bad; |
3f7eeb86 PP |
1240 | } |
1241 | ||
5b2fd993 JH |
1242 | #ifdef notdef |
1243 | { | |
1244 | BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE); | |
1245 | OCSP_RESPONSE_print(bp, resp, 0); /* extreme debug: stapling content */ | |
1246 | BIO_free(bp); | |
1247 | } | |
1248 | #endif | |
1249 | ||
ee5b1e28 | 1250 | if (!(basic_response = OCSP_response_get1_basic(resp))) |
3f7eeb86 PP |
1251 | { |
1252 | DEBUG(D_tls) | |
1253 | debug_printf("OCSP response parse error: unable to extract basic response.\n"); | |
f5d78688 | 1254 | goto bad; |
3f7eeb86 PP |
1255 | } |
1256 | ||
c3033f13 | 1257 | sk = cbinfo->verify_stack; |
3f7eeb86 PP |
1258 | verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ |
1259 | ||
1260 | /* May need to expose ability to adjust those flags? | |
1261 | OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT | |
1262 | OCSP_TRUSTOTHER OCSP_NOINTERN */ | |
1263 | ||
4c04137d | 1264 | /* This does a full verify on the OCSP proof before we load it for serving |
ee5b1e28 JH |
1265 | up; possibly overkill - just date-checks might be nice enough. |
1266 | ||
1267 | OCSP_basic_verify takes a "store" arg, but does not | |
1268 | use it for the chain verification, which is all we do | |
1269 | when OCSP_NOVERIFY is set. The content from the wire | |
1270 | "basic_response" and a cert-stack "sk" are all that is used. | |
1271 | ||
c3033f13 JH |
1272 | We have a stack, loaded in setup_certs() if tls_verify_certificates |
1273 | was a file (not a directory, or "system"). It is unfortunate we | |
1274 | cannot used the connection context store, as that would neatly | |
1275 | handle the "system" case too, but there seems to be no library | |
1276 | function for getting a stack from a store. | |
e3555426 | 1277 | [ In OpenSSL 1.1 - ? X509_STORE_CTX_get0_chain(ctx) ? ] |
c3033f13 JH |
1278 | We do not free the stack since it could be needed a second time for |
1279 | SNI handling. | |
1280 | ||
4c04137d | 1281 | Separately we might try to replace using OCSP_basic_verify() - which seems to not |
5ec37a55 | 1282 | be a public interface into the OpenSSL library (there's no manual entry) - |
ee5b1e28 | 1283 | But what with? We also use OCSP_basic_verify in the client stapling callback. |
4c04137d | 1284 | And there we NEED it; we must verify that status... unless the |
ee5b1e28 JH |
1285 | library does it for us anyway? */ |
1286 | ||
1287 | if ((i = OCSP_basic_verify(basic_response, sk, NULL, verify_flags)) < 0) | |
3f7eeb86 | 1288 | { |
ee5b1e28 JH |
1289 | DEBUG(D_tls) |
1290 | { | |
0abc5a13 | 1291 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
3f7eeb86 | 1292 | debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); |
f5d78688 JH |
1293 | } |
1294 | goto bad; | |
3f7eeb86 PP |
1295 | } |
1296 | ||
1297 | /* Here's the simplifying assumption: there's only one response, for the | |
1298 | one certificate we use, and nothing for anything else in a chain. If this | |
1299 | proves false, we need to extract a cert id from our issued cert | |
1300 | (tls_certificate) and use that for OCSP_resp_find_status() (which finds the | |
1301 | right cert in the stack and then calls OCSP_single_get0_status()). | |
1302 | ||
5b2fd993 JH |
1303 | I'm hoping to avoid reworking a bunch more of how we handle state here. |
1304 | ||
1305 | XXX that will change when we add support for (TLS1.3) whole-chain stapling | |
1306 | */ | |
ee5b1e28 JH |
1307 | |
1308 | if (!(single_response = OCSP_resp_get0(basic_response, 0))) | |
3f7eeb86 PP |
1309 | { |
1310 | DEBUG(D_tls) | |
1311 | debug_printf("Unable to get first response from OCSP basic response.\n"); | |
f5d78688 | 1312 | goto bad; |
3f7eeb86 PP |
1313 | } |
1314 | ||
1315 | status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd); | |
f5d78688 | 1316 | if (status != V_OCSP_CERTSTATUS_GOOD) |
3f7eeb86 | 1317 | { |
f5d78688 JH |
1318 | DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n", |
1319 | OCSP_cert_status_str(status), status, | |
1320 | OCSP_crl_reason_str(reason), reason); | |
1321 | goto bad; | |
3f7eeb86 PP |
1322 | } |
1323 | ||
1324 | if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
1325 | { | |
1326 | DEBUG(D_tls) debug_printf("OCSP status invalid times.\n"); | |
f5d78688 | 1327 | goto bad; |
3f7eeb86 PP |
1328 | } |
1329 | ||
f5d78688 | 1330 | supply_response: |
5b2fd993 JH |
1331 | /* Add the resp to the list used by tls_server_stapling_cb() */ |
1332 | { | |
1333 | ocsp_resplist ** op = &cbinfo->u_ocsp.server.olist, * oentry; | |
1334 | while (oentry = *op) | |
1335 | op = &oentry->next; | |
1336 | *op = oentry = store_get(sizeof(ocsp_resplist), FALSE); | |
1337 | oentry->next = NULL; | |
1338 | oentry->resp = resp; | |
1339 | } | |
f5d78688 JH |
1340 | return; |
1341 | ||
1342 | bad: | |
8768d548 | 1343 | if (f.running_in_test_harness) |
018058b2 JH |
1344 | { |
1345 | extern char ** environ; | |
d7978c0f | 1346 | if (environ) for (uschar ** p = USS environ; *p; p++) |
018058b2 JH |
1347 | if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) |
1348 | { | |
1349 | DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n"); | |
1350 | goto supply_response; | |
1351 | } | |
1352 | } | |
f5d78688 | 1353 | return; |
3f7eeb86 | 1354 | } |
5b2fd993 JH |
1355 | |
1356 | ||
1357 | static void | |
1358 | ocsp_free_response_list(tls_ext_ctx_cb * cbinfo) | |
1359 | { | |
1360 | for (ocsp_resplist * olist = cbinfo->u_ocsp.server.olist; olist; | |
1361 | olist = olist->next) | |
1362 | OCSP_RESPONSE_free(olist->resp); | |
1363 | cbinfo->u_ocsp.server.olist = NULL; | |
1364 | } | |
f2de3a33 | 1365 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
1366 | |
1367 | ||
1368 | ||
1369 | ||
23bb6982 JH |
1370 | /* Create and install a selfsigned certificate, for use in server mode */ |
1371 | ||
1372 | static int | |
cf0c6164 | 1373 | tls_install_selfsign(SSL_CTX * sctx, uschar ** errstr) |
23bb6982 JH |
1374 | { |
1375 | X509 * x509 = NULL; | |
1376 | EVP_PKEY * pkey; | |
1377 | RSA * rsa; | |
1378 | X509_NAME * name; | |
1379 | uschar * where; | |
1380 | ||
1381 | where = US"allocating pkey"; | |
1382 | if (!(pkey = EVP_PKEY_new())) | |
1383 | goto err; | |
1384 | ||
1385 | where = US"allocating cert"; | |
1386 | if (!(x509 = X509_new())) | |
1387 | goto err; | |
1388 | ||
1389 | where = US"generating pkey"; | |
6aac3239 | 1390 | if (!(rsa = rsa_callback(NULL, 0, 2048))) |
23bb6982 JH |
1391 | goto err; |
1392 | ||
4c04137d | 1393 | where = US"assigning pkey"; |
23bb6982 JH |
1394 | if (!EVP_PKEY_assign_RSA(pkey, rsa)) |
1395 | goto err; | |
1396 | ||
1397 | X509_set_version(x509, 2); /* N+1 - version 3 */ | |
1613fd68 | 1398 | ASN1_INTEGER_set(X509_get_serialNumber(x509), 1); |
23bb6982 JH |
1399 | X509_gmtime_adj(X509_get_notBefore(x509), 0); |
1400 | X509_gmtime_adj(X509_get_notAfter(x509), (long)60 * 60); /* 1 hour */ | |
1401 | X509_set_pubkey(x509, pkey); | |
1402 | ||
1403 | name = X509_get_subject_name(x509); | |
1404 | X509_NAME_add_entry_by_txt(name, "C", | |
4dc2379a | 1405 | MBSTRING_ASC, CUS "UK", -1, -1, 0); |
23bb6982 | 1406 | X509_NAME_add_entry_by_txt(name, "O", |
4dc2379a | 1407 | MBSTRING_ASC, CUS "Exim Developers", -1, -1, 0); |
23bb6982 | 1408 | X509_NAME_add_entry_by_txt(name, "CN", |
4dc2379a | 1409 | MBSTRING_ASC, CUS smtp_active_hostname, -1, -1, 0); |
23bb6982 JH |
1410 | X509_set_issuer_name(x509, name); |
1411 | ||
1412 | where = US"signing cert"; | |
1413 | if (!X509_sign(x509, pkey, EVP_md5())) | |
1414 | goto err; | |
1415 | ||
1416 | where = US"installing selfsign cert"; | |
1417 | if (!SSL_CTX_use_certificate(sctx, x509)) | |
1418 | goto err; | |
1419 | ||
1420 | where = US"installing selfsign key"; | |
1421 | if (!SSL_CTX_use_PrivateKey(sctx, pkey)) | |
1422 | goto err; | |
1423 | ||
1424 | return OK; | |
1425 | ||
1426 | err: | |
cf0c6164 | 1427 | (void) tls_error(where, NULL, NULL, errstr); |
23bb6982 JH |
1428 | if (x509) X509_free(x509); |
1429 | if (pkey) EVP_PKEY_free(pkey); | |
1430 | return DEFER; | |
1431 | } | |
1432 | ||
1433 | ||
1434 | ||
1435 | ||
ba86e143 JH |
1436 | static int |
1437 | tls_add_certfile(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, uschar * file, | |
1438 | uschar ** errstr) | |
1439 | { | |
5b2fd993 | 1440 | DEBUG(D_tls) debug_printf("tls_certificate file '%s'\n", file); |
ba86e143 JH |
1441 | if (!SSL_CTX_use_certificate_chain_file(sctx, CS file)) |
1442 | return tls_error(string_sprintf( | |
1443 | "SSL_CTX_use_certificate_chain_file file=%s", file), | |
1444 | cbinfo->host, NULL, errstr); | |
1445 | return 0; | |
1446 | } | |
1447 | ||
1448 | static int | |
1449 | tls_add_pkeyfile(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, uschar * file, | |
1450 | uschar ** errstr) | |
1451 | { | |
5b2fd993 | 1452 | DEBUG(D_tls) debug_printf("tls_privatekey file '%s'\n", file); |
ba86e143 JH |
1453 | if (!SSL_CTX_use_PrivateKey_file(sctx, CS file, SSL_FILETYPE_PEM)) |
1454 | return tls_error(string_sprintf( | |
1455 | "SSL_CTX_use_PrivateKey_file file=%s", file), cbinfo->host, NULL, errstr); | |
1456 | return 0; | |
1457 | } | |
1458 | ||
1459 | ||
7be682ca PP |
1460 | /************************************************* |
1461 | * Expand key and cert file specs * | |
1462 | *************************************************/ | |
1463 | ||
f5d78688 | 1464 | /* Called once during tls_init and possibly again during TLS setup, for a |
7be682ca PP |
1465 | new context, if Server Name Indication was used and tls_sni was seen in |
1466 | the certificate string. | |
1467 | ||
1468 | Arguments: | |
1469 | sctx the SSL_CTX* to update | |
1470 | cbinfo various parts of session state | |
cf0c6164 | 1471 | errstr error string pointer |
7be682ca PP |
1472 | |
1473 | Returns: OK/DEFER/FAIL | |
1474 | */ | |
1475 | ||
1476 | static int | |
5b2fd993 | 1477 | tls_expand_session_files(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, |
cf0c6164 | 1478 | uschar ** errstr) |
7be682ca | 1479 | { |
5b2fd993 | 1480 | uschar * expanded; |
7be682ca | 1481 | |
23bb6982 | 1482 | if (!cbinfo->certificate) |
7be682ca | 1483 | { |
ba86e143 | 1484 | if (!cbinfo->is_server) /* client */ |
23bb6982 | 1485 | return OK; |
afdb5e9c | 1486 | /* server */ |
cf0c6164 | 1487 | if (tls_install_selfsign(sctx, errstr) != OK) |
23bb6982 | 1488 | return DEFER; |
7be682ca | 1489 | } |
23bb6982 JH |
1490 | else |
1491 | { | |
ba86e143 JH |
1492 | int err; |
1493 | ||
5b2fd993 JH |
1494 | if ( !reexpand_tls_files_for_sni |
1495 | && ( Ustrstr(cbinfo->certificate, US"tls_sni") | |
1496 | || Ustrstr(cbinfo->certificate, US"tls_in_sni") | |
1497 | || Ustrstr(cbinfo->certificate, US"tls_out_sni") | |
1498 | ) ) | |
23bb6982 | 1499 | reexpand_tls_files_for_sni = TRUE; |
7be682ca | 1500 | |
cf0c6164 | 1501 | if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded, errstr)) |
23bb6982 JH |
1502 | return DEFER; |
1503 | ||
ba86e143 JH |
1504 | if (expanded) |
1505 | if (cbinfo->is_server) | |
1506 | { | |
1507 | const uschar * file_list = expanded; | |
1508 | int sep = 0; | |
1509 | uschar * file; | |
5b2fd993 JH |
1510 | #ifndef DISABLE_OCSP |
1511 | const uschar * olist = cbinfo->u_ocsp.server.file; | |
1512 | int osep = 0; | |
1513 | uschar * ofile; | |
1514 | ||
1515 | if (olist) | |
1516 | if (!expand_check(olist, US"tls_ocsp_file", USS &olist, errstr)) | |
1517 | return DEFER; | |
1518 | if (olist && !*olist) | |
1519 | olist = NULL; | |
1520 | ||
1521 | if ( cbinfo->u_ocsp.server.file_expanded && olist | |
1522 | && (Ustrcmp(olist, cbinfo->u_ocsp.server.file_expanded) == 0)) | |
1523 | { | |
1524 | DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n"); | |
1525 | olist = NULL; | |
1526 | } | |
1527 | else | |
1528 | { | |
1529 | ocsp_free_response_list(cbinfo); | |
1530 | cbinfo->u_ocsp.server.file_expanded = olist; | |
1531 | } | |
1532 | #endif | |
ba86e143 JH |
1533 | |
1534 | while (file = string_nextinlist(&file_list, &sep, NULL, 0)) | |
5b2fd993 | 1535 | { |
ba86e143 JH |
1536 | if ((err = tls_add_certfile(sctx, cbinfo, file, errstr))) |
1537 | return err; | |
5b2fd993 JH |
1538 | |
1539 | #ifndef DISABLE_OCSP | |
1540 | if (olist) | |
1541 | if ((ofile = string_nextinlist(&olist, &osep, NULL, 0))) | |
1542 | ocsp_load_response(sctx, cbinfo, ofile); | |
1543 | else | |
1544 | DEBUG(D_tls) debug_printf("ran out of ocsp file list\n"); | |
1545 | #endif | |
1546 | } | |
ba86e143 JH |
1547 | } |
1548 | else /* would there ever be a need for multiple client certs? */ | |
1549 | if ((err = tls_add_certfile(sctx, cbinfo, expanded, errstr))) | |
1550 | return err; | |
7be682ca | 1551 | |
5a2a0989 JH |
1552 | if ( cbinfo->privatekey |
1553 | && !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded, errstr)) | |
23bb6982 | 1554 | return DEFER; |
7be682ca | 1555 | |
23bb6982 JH |
1556 | /* If expansion was forced to fail, key_expanded will be NULL. If the result |
1557 | of the expansion is an empty string, ignore it also, and assume the private | |
1558 | key is in the same file as the certificate. */ | |
1559 | ||
1560 | if (expanded && *expanded) | |
ba86e143 JH |
1561 | if (cbinfo->is_server) |
1562 | { | |
1563 | const uschar * file_list = expanded; | |
1564 | int sep = 0; | |
1565 | uschar * file; | |
1566 | ||
1567 | while (file = string_nextinlist(&file_list, &sep, NULL, 0)) | |
1568 | if ((err = tls_add_pkeyfile(sctx, cbinfo, file, errstr))) | |
1569 | return err; | |
1570 | } | |
1571 | else /* would there ever be a need for multiple client certs? */ | |
1572 | if ((err = tls_add_pkeyfile(sctx, cbinfo, expanded, errstr))) | |
1573 | return err; | |
7be682ca PP |
1574 | } |
1575 | ||
1576 | return OK; | |
1577 | } | |
1578 | ||
1579 | ||
1580 | ||
1581 | ||
1582 | /************************************************* | |
1583 | * Callback to handle SNI * | |
1584 | *************************************************/ | |
1585 | ||
1586 | /* Called when acting as server during the TLS session setup if a Server Name | |
1587 | Indication extension was sent by the client. | |
1588 | ||
1589 | API documentation is OpenSSL s_server.c implementation. | |
1590 | ||
1591 | Arguments: | |
1592 | s SSL* of the current session | |
1593 | ad unknown (part of OpenSSL API) (unused) | |
1594 | arg Callback of "our" registered data | |
1595 | ||
1596 | Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK} | |
b10c87b3 JH |
1597 | |
1598 | XXX might need to change to using ClientHello callback, | |
1599 | per https://www.openssl.org/docs/manmaster/man3/SSL_client_hello_cb_fn.html | |
7be682ca PP |
1600 | */ |
1601 | ||
3bcbbbe2 | 1602 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
7be682ca PP |
1603 | static int |
1604 | tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg) | |
1605 | { | |
1606 | const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); | |
3f7eeb86 | 1607 | tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg; |
7be682ca | 1608 | int rc; |
3f0945ff | 1609 | int old_pool = store_pool; |
cf0c6164 | 1610 | uschar * dummy_errstr; |
7be682ca PP |
1611 | |
1612 | if (!servername) | |
1613 | return SSL_TLSEXT_ERR_OK; | |
1614 | ||
3f0945ff | 1615 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", servername, |
7be682ca PP |
1616 | reexpand_tls_files_for_sni ? "" : " (unused for certificate selection)"); |
1617 | ||
1618 | /* Make the extension value available for expansion */ | |
3f0945ff | 1619 | store_pool = POOL_PERM; |
89a80675 | 1620 | tls_in.sni = string_copy_taint(US servername, TRUE); |
3f0945ff | 1621 | store_pool = old_pool; |
7be682ca PP |
1622 | |
1623 | if (!reexpand_tls_files_for_sni) | |
1624 | return SSL_TLSEXT_ERR_OK; | |
1625 | ||
1626 | /* Can't find an SSL_CTX_clone() or equivalent, so we do it manually; | |
1627 | not confident that memcpy wouldn't break some internal reference counting. | |
1628 | Especially since there's a references struct member, which would be off. */ | |
1629 | ||
7a8b9519 JH |
1630 | #ifdef EXIM_HAVE_OPENSSL_TLS_METHOD |
1631 | if (!(server_sni = SSL_CTX_new(TLS_server_method()))) | |
1632 | #else | |
0df4ab80 | 1633 | if (!(server_sni = SSL_CTX_new(SSLv23_server_method()))) |
7a8b9519 | 1634 | #endif |
7be682ca | 1635 | { |
0abc5a13 | 1636 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
7be682ca | 1637 | DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring); |
5a2a0989 | 1638 | goto bad; |
7be682ca PP |
1639 | } |
1640 | ||
1641 | /* Not sure how many of these are actually needed, since SSL object | |
1642 | already exists. Might even need this selfsame callback, for reneg? */ | |
1643 | ||
817d9f57 JH |
1644 | SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx)); |
1645 | SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx)); | |
1646 | SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); | |
1647 | SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); | |
1648 | SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); | |
1649 | SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); | |
038597d2 | 1650 | |
cf0c6164 JH |
1651 | if ( !init_dh(server_sni, cbinfo->dhparam, NULL, &dummy_errstr) |
1652 | || !init_ecdh(server_sni, NULL, &dummy_errstr) | |
038597d2 | 1653 | ) |
5a2a0989 | 1654 | goto bad; |
038597d2 | 1655 | |
ca954d7f JH |
1656 | if ( cbinfo->server_cipher_list |
1657 | && !SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list)) | |
5a2a0989 | 1658 | goto bad; |
ca954d7f | 1659 | |
f2de3a33 | 1660 | #ifndef DISABLE_OCSP |
f5d78688 | 1661 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 1662 | { |
f5d78688 | 1663 | SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb); |
14c7b357 | 1664 | SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo); |
3f7eeb86 PP |
1665 | } |
1666 | #endif | |
7be682ca | 1667 | |
c3033f13 | 1668 | if ((rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, |
cf0c6164 | 1669 | verify_callback_server, &dummy_errstr)) != OK) |
5a2a0989 | 1670 | goto bad; |
7be682ca | 1671 | |
3f7eeb86 PP |
1672 | /* do this after setup_certs, because this can require the certs for verifying |
1673 | OCSP information. */ | |
cf0c6164 | 1674 | if ((rc = tls_expand_session_files(server_sni, cbinfo, &dummy_errstr)) != OK) |
5a2a0989 | 1675 | goto bad; |
a799883d | 1676 | |
7be682ca | 1677 | DEBUG(D_tls) debug_printf("Switching SSL context.\n"); |
817d9f57 | 1678 | SSL_set_SSL_CTX(s, server_sni); |
7be682ca | 1679 | return SSL_TLSEXT_ERR_OK; |
5a2a0989 JH |
1680 | |
1681 | bad: return SSL_TLSEXT_ERR_ALERT_FATAL; | |
7be682ca | 1682 | } |
3bcbbbe2 | 1683 | #endif /* EXIM_HAVE_OPENSSL_TLSEXT */ |
7be682ca PP |
1684 | |
1685 | ||
1686 | ||
1687 | ||
f2de3a33 | 1688 | #ifndef DISABLE_OCSP |
f5d78688 | 1689 | |
3f7eeb86 PP |
1690 | /************************************************* |
1691 | * Callback to handle OCSP Stapling * | |
1692 | *************************************************/ | |
1693 | ||
1694 | /* Called when acting as server during the TLS session setup if the client | |
1695 | requests OCSP information with a Certificate Status Request. | |
1696 | ||
1697 | Documentation via openssl s_server.c and the Apache patch from the OpenSSL | |
1698 | project. | |
1699 | ||
1700 | */ | |
1701 | ||
1702 | static int | |
f5d78688 | 1703 | tls_server_stapling_cb(SSL *s, void *arg) |
3f7eeb86 | 1704 | { |
5b2fd993 JH |
1705 | const tls_ext_ctx_cb * cbinfo = (tls_ext_ctx_cb *) arg; |
1706 | ocsp_resplist * olist = cbinfo->u_ocsp.server.olist; | |
1707 | uschar * response_der; /*XXX blob */ | |
3f7eeb86 PP |
1708 | int response_der_len; |
1709 | ||
af4a1bca | 1710 | DEBUG(D_tls) |
5b2fd993 JH |
1711 | debug_printf("Received TLS status request (OCSP stapling); %s response list\n", |
1712 | olist ? "have" : "lack"); | |
f5d78688 | 1713 | |
44662487 | 1714 | tls_in.ocsp = OCSP_NOT_RESP; |
5b2fd993 | 1715 | if (!olist) |
3f7eeb86 PP |
1716 | return SSL_TLSEXT_ERR_NOACK; |
1717 | ||
012dd02e | 1718 | #ifdef EXIM_HAVE_OPESSL_GET0_SERIAL |
5b2fd993 JH |
1719 | { |
1720 | const X509 * cert_sent = SSL_get_certificate(s); | |
1721 | const ASN1_INTEGER * cert_serial = X509_get0_serialNumber(cert_sent); | |
1722 | const BIGNUM * cert_bn = ASN1_INTEGER_to_BN(cert_serial, NULL); | |
1723 | const X509_NAME * cert_issuer = X509_get_issuer_name(cert_sent); | |
1724 | uschar * chash; | |
1725 | uint chash_len; | |
1726 | ||
1727 | for (; olist; olist = olist->next) | |
1728 | { | |
1729 | OCSP_BASICRESP * bs = OCSP_response_get1_basic(olist->resp); | |
1730 | const OCSP_SINGLERESP * single = OCSP_resp_get0(bs, 0); | |
1731 | const OCSP_CERTID * cid = OCSP_SINGLERESP_get0_id(single); | |
1732 | ASN1_INTEGER * res_cert_serial; | |
1733 | const BIGNUM * resp_bn; | |
1734 | ASN1_OCTET_STRING * res_cert_iNameHash; | |
1735 | ||
1736 | ||
1737 | (void) OCSP_id_get0_info(&res_cert_iNameHash, NULL, NULL, &res_cert_serial, | |
1738 | (OCSP_CERTID *) cid); | |
1739 | resp_bn = ASN1_INTEGER_to_BN(res_cert_serial, NULL); | |
1740 | ||
1741 | DEBUG(D_tls) | |
1742 | { | |
1743 | debug_printf("cert serial: %s\n", BN_bn2hex(cert_bn)); | |
1744 | debug_printf("resp serial: %s\n", BN_bn2hex(resp_bn)); | |
1745 | } | |
1746 | ||
1747 | if (BN_cmp(cert_bn, resp_bn) == 0) | |
1748 | { | |
1749 | DEBUG(D_tls) debug_printf("matched serial for ocsp\n"); | |
1750 | ||
1751 | /*XXX TODO: check the rest of the list for duplicate matches. | |
1752 | If any, need to also check the Issuer Name hash. | |
1753 | Without this, we will provide the wrong status in the case of | |
1754 | duplicate id. */ | |
1755 | ||
1756 | break; | |
1757 | } | |
1758 | DEBUG(D_tls) debug_printf("not match serial for ocsp\n"); | |
1759 | } | |
1760 | if (!olist) | |
1761 | { | |
1762 | DEBUG(D_tls) debug_printf("failed to find match for ocsp\n"); | |
1763 | return SSL_TLSEXT_ERR_NOACK; | |
1764 | } | |
1765 | } | |
012dd02e JH |
1766 | #else |
1767 | if (olist->next) | |
1768 | { | |
1769 | DEBUG(D_tls) debug_printf("OpenSSL version too early to support multi-leaf OCSP\n"); | |
1770 | return SSL_TLSEXT_ERR_NOACK; | |
1771 | } | |
1772 | #endif | |
5b2fd993 JH |
1773 | |
1774 | /*XXX could we do the i2d earlier, rather than during the callback? */ | |
3f7eeb86 | 1775 | response_der = NULL; |
5b2fd993 | 1776 | response_der_len = i2d_OCSP_RESPONSE(olist->resp, &response_der); |
3f7eeb86 PP |
1777 | if (response_der_len <= 0) |
1778 | return SSL_TLSEXT_ERR_NOACK; | |
1779 | ||
5e55c7a9 | 1780 | SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len); |
44662487 | 1781 | tls_in.ocsp = OCSP_VFIED; |
3f7eeb86 PP |
1782 | return SSL_TLSEXT_ERR_OK; |
1783 | } | |
1784 | ||
3f7eeb86 | 1785 | |
f5d78688 JH |
1786 | static void |
1787 | time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time) | |
1788 | { | |
1789 | BIO_printf(bp, "\t%s: ", str); | |
1790 | ASN1_GENERALIZEDTIME_print(bp, time); | |
1791 | BIO_puts(bp, "\n"); | |
1792 | } | |
1793 | ||
1794 | static int | |
1795 | tls_client_stapling_cb(SSL *s, void *arg) | |
1796 | { | |
1797 | tls_ext_ctx_cb * cbinfo = arg; | |
1798 | const unsigned char * p; | |
1799 | int len; | |
1800 | OCSP_RESPONSE * rsp; | |
1801 | OCSP_BASICRESP * bs; | |
1802 | int i; | |
1803 | ||
1804 | DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):"); | |
1805 | len = SSL_get_tlsext_status_ocsp_resp(s, &p); | |
1806 | if(!p) | |
1807 | { | |
44662487 | 1808 | /* Expect this when we requested ocsp but got none */ |
6c6d6e48 | 1809 | if (cbinfo->u_ocsp.client.verify_required && LOGGING(tls_cipher)) |
44662487 | 1810 | log_write(0, LOG_MAIN, "Received TLS status callback, null content"); |
f5d78688 JH |
1811 | else |
1812 | DEBUG(D_tls) debug_printf(" null\n"); | |
44662487 | 1813 | return cbinfo->u_ocsp.client.verify_required ? 0 : 1; |
f5d78688 | 1814 | } |
018058b2 | 1815 | |
c82de233 JH |
1816 | if (!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) |
1817 | { | |
1818 | tls_out.ocsp = OCSP_FAILED; /*XXX should use tlsp-> to permit concurrent outbound */ | |
6c6d6e48 | 1819 | if (LOGGING(tls_cipher)) |
1eca31ca | 1820 | log_write(0, LOG_MAIN, "Received TLS cert status response, parse error"); |
f5d78688 JH |
1821 | else |
1822 | DEBUG(D_tls) debug_printf(" parse error\n"); | |
1823 | return 0; | |
c82de233 | 1824 | } |
f5d78688 | 1825 | |
c82de233 | 1826 | if (!(bs = OCSP_response_get1_basic(rsp))) |
f5d78688 | 1827 | { |
018058b2 | 1828 | tls_out.ocsp = OCSP_FAILED; |
6c6d6e48 | 1829 | if (LOGGING(tls_cipher)) |
1eca31ca | 1830 | log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response"); |
f5d78688 JH |
1831 | else |
1832 | DEBUG(D_tls) debug_printf(" error parsing response\n"); | |
1833 | OCSP_RESPONSE_free(rsp); | |
1834 | return 0; | |
1835 | } | |
1836 | ||
1837 | /* We'd check the nonce here if we'd put one in the request. */ | |
1838 | /* However that would defeat cacheability on the server so we don't. */ | |
1839 | ||
f5d78688 JH |
1840 | /* This section of code reworked from OpenSSL apps source; |
1841 | The OpenSSL Project retains copyright: | |
1842 | Copyright (c) 1999 The OpenSSL Project. All rights reserved. | |
1843 | */ | |
1844 | { | |
1845 | BIO * bp = NULL; | |
f5d78688 JH |
1846 | int status, reason; |
1847 | ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; | |
1848 | ||
57887ecc | 1849 | DEBUG(D_tls) bp = BIO_new_fp(debug_file, BIO_NOCLOSE); |
f5d78688 JH |
1850 | |
1851 | /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */ | |
1852 | ||
1853 | /* Use the chain that verified the server cert to verify the stapled info */ | |
1854 | /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */ | |
1855 | ||
c3033f13 | 1856 | if ((i = OCSP_basic_verify(bs, cbinfo->verify_stack, |
44662487 | 1857 | cbinfo->u_ocsp.client.verify_store, 0)) <= 0) |
f5d78688 | 1858 | { |
018058b2 | 1859 | tls_out.ocsp = OCSP_FAILED; |
57887ecc JH |
1860 | if (LOGGING(tls_cipher)) log_write(0, LOG_MAIN, |
1861 | "Received TLS cert status response, itself unverifiable: %s", | |
1862 | ERR_reason_error_string(ERR_peek_error())); | |
f5d78688 JH |
1863 | BIO_printf(bp, "OCSP response verify failure\n"); |
1864 | ERR_print_errors(bp); | |
57887ecc | 1865 | OCSP_RESPONSE_print(bp, rsp, 0); |
c8dfb21d | 1866 | goto failed; |
f5d78688 JH |
1867 | } |
1868 | ||
1869 | BIO_printf(bp, "OCSP response well-formed and signed OK\n"); | |
1870 | ||
c8dfb21d JH |
1871 | /*XXX So we have a good stapled OCSP status. How do we know |
1872 | it is for the cert of interest? OpenSSL 1.1.0 has a routine | |
1873 | OCSP_resp_find_status() which matches on a cert id, which presumably | |
1874 | we should use. Making an id needs OCSP_cert_id_new(), which takes | |
1875 | issuerName, issuerKey, serialNumber. Are they all in the cert? | |
1876 | ||
1877 | For now, carry on blindly accepting the resp. */ | |
1878 | ||
f5d78688 | 1879 | { |
f5d78688 JH |
1880 | OCSP_SINGLERESP * single; |
1881 | ||
c8dfb21d JH |
1882 | #ifdef EXIM_HAVE_OCSP_RESP_COUNT |
1883 | if (OCSP_resp_count(bs) != 1) | |
1884 | #else | |
1885 | STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; | |
f5d78688 | 1886 | if (sk_OCSP_SINGLERESP_num(sresp) != 1) |
c8dfb21d | 1887 | #endif |
f5d78688 | 1888 | { |
018058b2 | 1889 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1890 | log_write(0, LOG_MAIN, "OCSP stapling " |
1891 | "with multiple responses not handled"); | |
c8dfb21d | 1892 | goto failed; |
f5d78688 JH |
1893 | } |
1894 | single = OCSP_resp_get0(bs, 0); | |
44662487 JH |
1895 | status = OCSP_single_get0_status(single, &reason, &rev, |
1896 | &thisupd, &nextupd); | |
f5d78688 JH |
1897 | } |
1898 | ||
f5d78688 JH |
1899 | DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd); |
1900 | DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd); | |
44662487 JH |
1901 | if (!OCSP_check_validity(thisupd, nextupd, |
1902 | EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE)) | |
f5d78688 | 1903 | { |
018058b2 | 1904 | tls_out.ocsp = OCSP_FAILED; |
f5d78688 JH |
1905 | DEBUG(D_tls) ERR_print_errors(bp); |
1906 | log_write(0, LOG_MAIN, "Server OSCP dates invalid"); | |
f5d78688 | 1907 | } |
44662487 | 1908 | else |
f5d78688 | 1909 | { |
44662487 JH |
1910 | DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n", |
1911 | OCSP_cert_status_str(status)); | |
1912 | switch(status) | |
1913 | { | |
1914 | case V_OCSP_CERTSTATUS_GOOD: | |
44662487 | 1915 | tls_out.ocsp = OCSP_VFIED; |
018058b2 | 1916 | i = 1; |
c8dfb21d | 1917 | goto good; |
44662487 | 1918 | case V_OCSP_CERTSTATUS_REVOKED: |
018058b2 | 1919 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1920 | log_write(0, LOG_MAIN, "Server certificate revoked%s%s", |
1921 | reason != -1 ? "; reason: " : "", | |
1922 | reason != -1 ? OCSP_crl_reason_str(reason) : ""); | |
1923 | DEBUG(D_tls) time_print(bp, "Revocation Time", rev); | |
44662487 JH |
1924 | break; |
1925 | default: | |
018058b2 | 1926 | tls_out.ocsp = OCSP_FAILED; |
44662487 JH |
1927 | log_write(0, LOG_MAIN, |
1928 | "Server certificate status unknown, in OCSP stapling"); | |
44662487 JH |
1929 | break; |
1930 | } | |
f5d78688 | 1931 | } |
c8dfb21d JH |
1932 | failed: |
1933 | i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; | |
1934 | good: | |
f5d78688 JH |
1935 | BIO_free(bp); |
1936 | } | |
1937 | ||
1938 | OCSP_RESPONSE_free(rsp); | |
1939 | return i; | |
1940 | } | |
f2de3a33 | 1941 | #endif /*!DISABLE_OCSP*/ |
3f7eeb86 PP |
1942 | |
1943 | ||
059ec3d9 PH |
1944 | /************************************************* |
1945 | * Initialize for TLS * | |
1946 | *************************************************/ | |
1947 | ||
e51c7be2 JH |
1948 | /* Called from both server and client code, to do preliminary initialization |
1949 | of the library. We allocate and return a context structure. | |
059ec3d9 PH |
1950 | |
1951 | Arguments: | |
946ecbe0 | 1952 | ctxp returned SSL context |
059ec3d9 PH |
1953 | host connected host, if client; NULL if server |
1954 | dhparam DH parameter file | |
1955 | certificate certificate file | |
1956 | privatekey private key | |
f5d78688 | 1957 | ocsp_file file of stapling info (server); flag for require ocsp (client) |
059ec3d9 | 1958 | addr address if client; NULL if server (for some randomness) |
946ecbe0 | 1959 | cbp place to put allocated callback context |
cf0c6164 | 1960 | errstr error string pointer |
059ec3d9 PH |
1961 | |
1962 | Returns: OK/DEFER/FAIL | |
1963 | */ | |
1964 | ||
1965 | static int | |
817d9f57 | 1966 | tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate, |
3f7eeb86 | 1967 | uschar *privatekey, |
f2de3a33 | 1968 | #ifndef DISABLE_OCSP |
5b2fd993 | 1969 | uschar *ocsp_file, |
3f7eeb86 | 1970 | #endif |
b10c87b3 JH |
1971 | address_item *addr, tls_ext_ctx_cb ** cbp, |
1972 | tls_support * tlsp, | |
1973 | uschar ** errstr) | |
059ec3d9 | 1974 | { |
7006ee24 | 1975 | SSL_CTX * ctx; |
77bb000f | 1976 | long init_options; |
7be682ca | 1977 | int rc; |
a7538db1 | 1978 | tls_ext_ctx_cb * cbinfo; |
7be682ca PP |
1979 | |
1980 | cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); | |
b10c87b3 | 1981 | cbinfo->tlsp = tlsp; |
7be682ca PP |
1982 | cbinfo->certificate = certificate; |
1983 | cbinfo->privatekey = privatekey; | |
a6510420 | 1984 | cbinfo->is_server = host==NULL; |
f2de3a33 | 1985 | #ifndef DISABLE_OCSP |
c3033f13 | 1986 | cbinfo->verify_stack = NULL; |
a6510420 | 1987 | if (!host) |
f5d78688 JH |
1988 | { |
1989 | cbinfo->u_ocsp.server.file = ocsp_file; | |
1990 | cbinfo->u_ocsp.server.file_expanded = NULL; | |
5b2fd993 | 1991 | cbinfo->u_ocsp.server.olist = NULL; |
f5d78688 JH |
1992 | } |
1993 | else | |
1994 | cbinfo->u_ocsp.client.verify_store = NULL; | |
3f7eeb86 | 1995 | #endif |
7be682ca | 1996 | cbinfo->dhparam = dhparam; |
0df4ab80 | 1997 | cbinfo->server_cipher_list = NULL; |
7be682ca | 1998 | cbinfo->host = host; |
0cbf2b82 | 1999 | #ifndef DISABLE_EVENT |
a7538db1 JH |
2000 | cbinfo->event_action = NULL; |
2001 | #endif | |
77bb000f | 2002 | |
7434882d | 2003 | #ifdef EXIM_NEED_OPENSSL_INIT |
059ec3d9 PH |
2004 | SSL_load_error_strings(); /* basic set up */ |
2005 | OpenSSL_add_ssl_algorithms(); | |
7434882d | 2006 | #endif |
059ec3d9 | 2007 | |
c8dfb21d | 2008 | #ifdef EXIM_HAVE_SHA256 |
77bb000f | 2009 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the |
a0475b69 TK |
2010 | list of available digests. */ |
2011 | EVP_add_digest(EVP_sha256()); | |
cf1ef1a9 | 2012 | #endif |
a0475b69 | 2013 | |
f0f5a555 PP |
2014 | /* Create a context. |
2015 | The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant | |
2016 | negotiation in the different methods; as far as I can tell, the only | |
2017 | *_{server,client}_method which allows negotiation is SSLv23, which exists even | |
2018 | when OpenSSL is built without SSLv2 support. | |
2019 | By disabling with openssl_options, we can let admins re-enable with the | |
2020 | existing knob. */ | |
059ec3d9 | 2021 | |
7a8b9519 JH |
2022 | #ifdef EXIM_HAVE_OPENSSL_TLS_METHOD |
2023 | if (!(ctx = SSL_CTX_new(host ? TLS_client_method() : TLS_server_method()))) | |
2024 | #else | |
7006ee24 | 2025 | if (!(ctx = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method()))) |
7a8b9519 | 2026 | #endif |
7006ee24 | 2027 | return tls_error(US"SSL_CTX_new", host, NULL, errstr); |
059ec3d9 PH |
2028 | |
2029 | /* It turns out that we need to seed the random number generator this early in | |
2030 | order to get the full complement of ciphers to work. It took me roughly a day | |
2031 | of work to discover this by experiment. | |
2032 | ||
2033 | On systems that have /dev/urandom, SSL may automatically seed itself from | |
2034 | there. Otherwise, we have to make something up as best we can. Double check | |
2035 | afterwards. */ | |
2036 | ||
2037 | if (!RAND_status()) | |
2038 | { | |
2039 | randstuff r; | |
9e3331ea | 2040 | gettimeofday(&r.tv, NULL); |
059ec3d9 PH |
2041 | r.p = getpid(); |
2042 | ||
5903c6ff JH |
2043 | RAND_seed(US (&r), sizeof(r)); |
2044 | RAND_seed(US big_buffer, big_buffer_size); | |
2045 | if (addr != NULL) RAND_seed(US addr, sizeof(addr)); | |
059ec3d9 PH |
2046 | |
2047 | if (!RAND_status()) | |
7199e1ee | 2048 | return tls_error(US"RAND_status", host, |
cf0c6164 | 2049 | US"unable to seed random number generator", errstr); |
059ec3d9 PH |
2050 | } |
2051 | ||
2052 | /* Set up the information callback, which outputs if debugging is at a suitable | |
2053 | level. */ | |
2054 | ||
b10c87b3 JH |
2055 | DEBUG(D_tls) |
2056 | { | |
2057 | SSL_CTX_set_info_callback(ctx, (void (*)())info_callback); | |
e570d136 JH |
2058 | #if defined(EXIM_HAVE_OPESSL_TRACE) && !defined(OPENSSL_NO_SSL_TRACE) |
2059 | /* this needs a debug build of OpenSSL */ | |
b10c87b3 JH |
2060 | SSL_CTX_set_msg_callback(ctx, (void (*)())SSL_trace); |
2061 | #endif | |
8a40db1c | 2062 | #ifdef OPENSSL_HAVE_KEYLOG_CB |
b10c87b3 | 2063 | SSL_CTX_set_keylog_callback(ctx, (void (*)())keylog_callback); |
8a40db1c | 2064 | #endif |
b10c87b3 | 2065 | } |
059ec3d9 | 2066 | |
c80c5570 | 2067 | /* Automatically re-try reads/writes after renegotiation. */ |
7006ee24 | 2068 | (void) SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY); |
c80c5570 | 2069 | |
77bb000f PP |
2070 | /* Apply administrator-supplied work-arounds. |
2071 | Historically we applied just one requested option, | |
2072 | SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we | |
2073 | moved to an administrator-controlled list of options to specify and | |
2074 | grandfathered in the first one as the default value for "openssl_options". | |
059ec3d9 | 2075 | |
77bb000f PP |
2076 | No OpenSSL version number checks: the options we accept depend upon the |
2077 | availability of the option value macros from OpenSSL. */ | |
059ec3d9 | 2078 | |
7006ee24 | 2079 | if (!tls_openssl_options_parse(openssl_options, &init_options)) |
cf0c6164 | 2080 | return tls_error(US"openssl_options parsing failed", host, NULL, errstr); |
77bb000f | 2081 | |
b10c87b3 JH |
2082 | #ifdef EXPERIMENTAL_TLS_RESUME |
2083 | tlsp->resumption = RESUME_SUPPORTED; | |
2084 | #endif | |
77bb000f PP |
2085 | if (init_options) |
2086 | { | |
b10c87b3 JH |
2087 | #ifdef EXPERIMENTAL_TLS_RESUME |
2088 | /* Should the server offer session resumption? */ | |
2089 | if (!host && verify_check_host(&tls_resumption_hosts) == OK) | |
2090 | { | |
2091 | DEBUG(D_tls) debug_printf("tls_resumption_hosts overrides openssl_options\n"); | |
2092 | init_options &= ~SSL_OP_NO_TICKET; | |
2093 | tlsp->resumption |= RESUME_SERVER_TICKET; /* server will give ticket on request */ | |
2094 | tlsp->host_resumable = TRUE; | |
2095 | } | |
2096 | #endif | |
2097 | ||
77bb000f | 2098 | DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); |
7006ee24 | 2099 | if (!(SSL_CTX_set_options(ctx, init_options))) |
77bb000f | 2100 | return tls_error(string_sprintf( |
cf0c6164 | 2101 | "SSL_CTX_set_option(%#lx)", init_options), host, NULL, errstr); |
77bb000f PP |
2102 | } |
2103 | else | |
2104 | DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); | |
059ec3d9 | 2105 | |
a28050f8 JH |
2106 | /* We'd like to disable session cache unconditionally, but foolish Outlook |
2107 | Express clients then give up the first TLS connection and make a second one | |
2108 | (which works). Only when there is an IMAP service on the same machine. | |
2109 | Presumably OE is trying to use the cache for A on B. Leave it enabled for | |
2110 | now, until we work out a decent way of presenting control to the config. It | |
2111 | will never be used because we use a new context every time. */ | |
2112 | #ifdef notdef | |
7006ee24 | 2113 | (void) SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF); |
a28050f8 | 2114 | #endif |
7006ee24 | 2115 | |
059ec3d9 | 2116 | /* Initialize with DH parameters if supplied */ |
10ca4f1c | 2117 | /* Initialize ECDH temp key parameter selection */ |
059ec3d9 | 2118 | |
7006ee24 JH |
2119 | if ( !init_dh(ctx, dhparam, host, errstr) |
2120 | || !init_ecdh(ctx, host, errstr) | |
038597d2 PP |
2121 | ) |
2122 | return DEFER; | |
059ec3d9 | 2123 | |
3f7eeb86 | 2124 | /* Set up certificate and key (and perhaps OCSP info) */ |
059ec3d9 | 2125 | |
7006ee24 | 2126 | if ((rc = tls_expand_session_files(ctx, cbinfo, errstr)) != OK) |
23bb6982 | 2127 | return rc; |
c91535f3 | 2128 | |
c3033f13 JH |
2129 | /* If we need to handle SNI or OCSP, do so */ |
2130 | ||
3bcbbbe2 | 2131 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
c3033f13 JH |
2132 | # ifndef DISABLE_OCSP |
2133 | if (!(cbinfo->verify_stack = sk_X509_new_null())) | |
2134 | { | |
2135 | DEBUG(D_tls) debug_printf("failed to create stack for stapling verify\n"); | |
2136 | return FAIL; | |
2137 | } | |
2138 | # endif | |
2139 | ||
7a8b9519 | 2140 | if (!host) /* server */ |
3f0945ff | 2141 | { |
f2de3a33 | 2142 | # ifndef DISABLE_OCSP |
5b2fd993 | 2143 | /* We check u_ocsp.server.file, not server.olist, because we care about if |
3f7eeb86 PP |
2144 | the option exists, not what the current expansion might be, as SNI might |
2145 | change the certificate and OCSP file in use between now and the time the | |
2146 | callback is invoked. */ | |
f5d78688 | 2147 | if (cbinfo->u_ocsp.server.file) |
3f7eeb86 | 2148 | { |
7006ee24 JH |
2149 | SSL_CTX_set_tlsext_status_cb(ctx, tls_server_stapling_cb); |
2150 | SSL_CTX_set_tlsext_status_arg(ctx, cbinfo); | |
3f7eeb86 | 2151 | } |
f5d78688 | 2152 | # endif |
3f0945ff PP |
2153 | /* We always do this, so that $tls_sni is available even if not used in |
2154 | tls_certificate */ | |
7006ee24 JH |
2155 | SSL_CTX_set_tlsext_servername_callback(ctx, tls_servername_cb); |
2156 | SSL_CTX_set_tlsext_servername_arg(ctx, cbinfo); | |
3f0945ff | 2157 | } |
f2de3a33 | 2158 | # ifndef DISABLE_OCSP |
f5d78688 JH |
2159 | else /* client */ |
2160 | if(ocsp_file) /* wanting stapling */ | |
2161 | { | |
2162 | if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new())) | |
2163 | { | |
2164 | DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n"); | |
2165 | return FAIL; | |
2166 | } | |
7006ee24 JH |
2167 | SSL_CTX_set_tlsext_status_cb(ctx, tls_client_stapling_cb); |
2168 | SSL_CTX_set_tlsext_status_arg(ctx, cbinfo); | |
f5d78688 JH |
2169 | } |
2170 | # endif | |
7be682ca | 2171 | #endif |
059ec3d9 | 2172 | |
e51c7be2 | 2173 | cbinfo->verify_cert_hostnames = NULL; |
e51c7be2 | 2174 | |
c8dfb21d | 2175 | #ifdef EXIM_HAVE_EPHEM_RSA_KEX |
059ec3d9 | 2176 | /* Set up the RSA callback */ |
7006ee24 | 2177 | SSL_CTX_set_tmp_rsa_callback(ctx, rsa_callback); |
c8dfb21d | 2178 | #endif |
059ec3d9 | 2179 | |
b10c87b3 JH |
2180 | /* Finally, set the session cache timeout, and we are done. |
2181 | The period appears to be also used for (server-generated) session tickets */ | |
059ec3d9 | 2182 | |
7006ee24 | 2183 | SSL_CTX_set_timeout(ctx, ssl_session_timeout); |
059ec3d9 | 2184 | DEBUG(D_tls) debug_printf("Initialized TLS\n"); |
7be682ca | 2185 | |
817d9f57 | 2186 | *cbp = cbinfo; |
7006ee24 | 2187 | *ctxp = ctx; |
7be682ca | 2188 | |
059ec3d9 PH |
2189 | return OK; |
2190 | } | |
2191 | ||
2192 | ||
2193 | ||
2194 | ||
2195 | /************************************************* | |
2196 | * Get name of cipher in use * | |
2197 | *************************************************/ | |
2198 | ||
817d9f57 | 2199 | /* |
059ec3d9 | 2200 | Argument: pointer to an SSL structure for the connection |
817d9f57 | 2201 | pointer to number of bits for cipher |
f1be21cf | 2202 | Returns: pointer to allocated string in perm-pool |
059ec3d9 PH |
2203 | */ |
2204 | ||
f1be21cf JH |
2205 | static uschar * |
2206 | construct_cipher_name(SSL * ssl, int * bits) | |
059ec3d9 | 2207 | { |
f1be21cf | 2208 | int pool = store_pool; |
7a8b9519 | 2209 | /* With OpenSSL 1.0.0a, 'c' needs to be const but the documentation doesn't |
57b3a7f5 PP |
2210 | yet reflect that. It should be a safe change anyway, even 0.9.8 versions have |
2211 | the accessor functions use const in the prototype. */ | |
059ec3d9 | 2212 | |
7a8b9519 JH |
2213 | const uschar * ver = CUS SSL_get_version(ssl); |
2214 | const SSL_CIPHER * c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); | |
f1be21cf | 2215 | uschar * s; |
059ec3d9 | 2216 | |
817d9f57 | 2217 | SSL_CIPHER_get_bits(c, bits); |
059ec3d9 | 2218 | |
f1be21cf JH |
2219 | store_pool = POOL_PERM; |
2220 | s = string_sprintf("%s:%s:%u", ver, SSL_CIPHER_get_name(c), *bits); | |
2221 | store_pool = pool; | |
2222 | DEBUG(D_tls) debug_printf("Cipher: %s\n", s); | |
2223 | return s; | |
2224 | } | |
2225 | ||
059ec3d9 | 2226 | |
f1be21cf JH |
2227 | /* Get IETF-standard name for ciphersuite. |
2228 | Argument: pointer to an SSL structure for the connection | |
2229 | Returns: pointer to string | |
2230 | */ | |
2231 | ||
2232 | static const uschar * | |
2233 | cipher_stdname_ssl(SSL * ssl) | |
2234 | { | |
2235 | #ifdef EXIM_HAVE_OPENSSL_CIPHER_STD_NAME | |
2236 | return CUS SSL_CIPHER_standard_name(SSL_get_current_cipher(ssl)); | |
2237 | #else | |
2238 | ushort id = 0xffff & SSL_CIPHER_get_id(SSL_get_current_cipher(ssl)); | |
2239 | return cipher_stdname(id >> 8, id & 0xff); | |
2240 | #endif | |
059ec3d9 PH |
2241 | } |
2242 | ||
2243 | ||
f69979cf | 2244 | static void |
70e384dd | 2245 | peer_cert(SSL * ssl, tls_support * tlsp, uschar * peerdn, unsigned siz) |
f69979cf JH |
2246 | { |
2247 | /*XXX we might consider a list-of-certs variable for the cert chain. | |
2248 | SSL_get_peer_cert_chain(SSL*). We'd need a new variable type and support | |
2249 | in list-handling functions, also consider the difference between the entire | |
2250 | chain and the elements sent by the peer. */ | |
2251 | ||
70e384dd JH |
2252 | tlsp->peerdn = NULL; |
2253 | ||
f69979cf JH |
2254 | /* Will have already noted peercert on a verify fail; possibly not the leaf */ |
2255 | if (!tlsp->peercert) | |
2256 | tlsp->peercert = SSL_get_peer_certificate(ssl); | |
2257 | /* Beware anonymous ciphers which lead to server_cert being NULL */ | |
2258 | if (tlsp->peercert) | |
70e384dd JH |
2259 | if (!X509_NAME_oneline(X509_get_subject_name(tlsp->peercert), CS peerdn, siz)) |
2260 | { DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); } | |
2261 | else | |
2262 | { | |
4a1bd6b9 JH |
2263 | int oldpool = store_pool; |
2264 | ||
2265 | peerdn[siz-1] = '\0'; /* paranoia */ | |
2266 | store_pool = POOL_PERM; | |
2267 | tlsp->peerdn = string_copy(peerdn); | |
2268 | store_pool = oldpool; | |
2269 | ||
2270 | /* We used to set CV in the cert-verify callbacks (either plain or dane) | |
2271 | but they don't get called on session-resumption. So use the official | |
2272 | interface, which uses the resumed value. Unfortunately this claims verified | |
2273 | when it actually failed but we're in try-verify mode, due to us wanting the | |
2274 | knowlege that it failed so needing to have the callback and forcing a | |
2275 | permissive return. If we don't force it, the TLS startup is failed. | |
f4e62a87 JH |
2276 | The extra bit of information is set in verify_override in the cb, stashed |
2277 | for resumption next to the TLS session, and used here. */ | |
4a1bd6b9 JH |
2278 | |
2279 | if (!tlsp->verify_override) | |
2280 | tlsp->certificate_verified = SSL_get_verify_result(ssl) == X509_V_OK; | |
70e384dd | 2281 | } |
f69979cf JH |
2282 | } |
2283 | ||
2284 | ||
059ec3d9 PH |
2285 | |
2286 | ||
2287 | ||
2288 | /************************************************* | |
2289 | * Set up for verifying certificates * | |
2290 | *************************************************/ | |
2291 | ||
0e8aed8a | 2292 | #ifndef DISABLE_OCSP |
c3033f13 JH |
2293 | /* Load certs from file, return TRUE on success */ |
2294 | ||
2295 | static BOOL | |
2296 | chain_from_pem_file(const uschar * file, STACK_OF(X509) * verify_stack) | |
2297 | { | |
2298 | BIO * bp; | |
2299 | X509 * x; | |
2300 | ||
dec766a1 WB |
2301 | while (sk_X509_num(verify_stack) > 0) |
2302 | X509_free(sk_X509_pop(verify_stack)); | |
2303 | ||
c3033f13 JH |
2304 | if (!(bp = BIO_new_file(CS file, "r"))) return FALSE; |
2305 | while ((x = PEM_read_bio_X509(bp, NULL, 0, NULL))) | |
2306 | sk_X509_push(verify_stack, x); | |
2307 | BIO_free(bp); | |
2308 | return TRUE; | |
2309 | } | |
0e8aed8a | 2310 | #endif |
c3033f13 JH |
2311 | |
2312 | ||
2313 | ||
dec766a1 WB |
2314 | /* Called by both client and server startup; on the server possibly |
2315 | repeated after a Server Name Indication. | |
059ec3d9 PH |
2316 | |
2317 | Arguments: | |
7be682ca | 2318 | sctx SSL_CTX* to initialise |
059ec3d9 PH |
2319 | certs certs file or NULL |
2320 | crl CRL file or NULL | |
2321 | host NULL in a server; the remote host in a client | |
2322 | optional TRUE if called from a server for a host in tls_try_verify_hosts; | |
2323 | otherwise passed as FALSE | |
983207c1 | 2324 | cert_vfy_cb Callback function for certificate verification |
cf0c6164 | 2325 | errstr error string pointer |
059ec3d9 PH |
2326 | |
2327 | Returns: OK/DEFER/FAIL | |
2328 | */ | |
2329 | ||
2330 | static int | |
983207c1 | 2331 | setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, |
cf0c6164 | 2332 | int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr) |
059ec3d9 PH |
2333 | { |
2334 | uschar *expcerts, *expcrl; | |
2335 | ||
cf0c6164 | 2336 | if (!expand_check(certs, US"tls_verify_certificates", &expcerts, errstr)) |
059ec3d9 | 2337 | return DEFER; |
57cc2785 | 2338 | DEBUG(D_tls) debug_printf("tls_verify_certificates: %s\n", expcerts); |
059ec3d9 | 2339 | |
10a831a3 | 2340 | if (expcerts && *expcerts) |
059ec3d9 | 2341 | { |
10a831a3 JH |
2342 | /* Tell the library to use its compiled-in location for the system default |
2343 | CA bundle. Then add the ones specified in the config, if any. */ | |
cb1d7830 | 2344 | |
10a831a3 | 2345 | if (!SSL_CTX_set_default_verify_paths(sctx)) |
cf0c6164 | 2346 | return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL, errstr); |
10a831a3 JH |
2347 | |
2348 | if (Ustrcmp(expcerts, "system") != 0) | |
059ec3d9 | 2349 | { |
cb1d7830 JH |
2350 | struct stat statbuf; |
2351 | ||
cb1d7830 JH |
2352 | if (Ustat(expcerts, &statbuf) < 0) |
2353 | { | |
2354 | log_write(0, LOG_MAIN|LOG_PANIC, | |
2355 | "failed to stat %s for certificates", expcerts); | |
2356 | return DEFER; | |
2357 | } | |
059ec3d9 | 2358 | else |
059ec3d9 | 2359 | { |
cb1d7830 JH |
2360 | uschar *file, *dir; |
2361 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
2362 | { file = NULL; dir = expcerts; } | |
2363 | else | |
c3033f13 JH |
2364 | { |
2365 | file = expcerts; dir = NULL; | |
2366 | #ifndef DISABLE_OCSP | |
2367 | /* In the server if we will be offering an OCSP proof, load chain from | |
2368 | file for verifying the OCSP proof at load time. */ | |
2369 | ||
5b2fd993 JH |
2370 | /*XXX Glitch! The file here is tls_verify_certs: the chain for verifying the client cert. |
2371 | This is inconsistent with the need to verify the OCSP proof of the server cert. | |
2372 | */ | |
2373 | ||
c3033f13 JH |
2374 | if ( !host |
2375 | && statbuf.st_size > 0 | |
2376 | && server_static_cbinfo->u_ocsp.server.file | |
2377 | && !chain_from_pem_file(file, server_static_cbinfo->verify_stack) | |
2378 | ) | |
2379 | { | |
2380 | log_write(0, LOG_MAIN|LOG_PANIC, | |
57887ecc | 2381 | "failed to load cert chain from %s", file); |
c3033f13 JH |
2382 | return DEFER; |
2383 | } | |
2384 | #endif | |
2385 | } | |
cb1d7830 JH |
2386 | |
2387 | /* If a certificate file is empty, the next function fails with an | |
2388 | unhelpful error message. If we skip it, we get the correct behaviour (no | |
2389 | certificates are recognized, but the error message is still misleading (it | |
c3033f13 | 2390 | says no certificate was supplied). But this is better. */ |
cb1d7830 | 2391 | |
f2f2c91b JH |
2392 | if ( (!file || statbuf.st_size > 0) |
2393 | && !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) | |
cf0c6164 | 2394 | return tls_error(US"SSL_CTX_load_verify_locations", host, NULL, errstr); |
cb1d7830 JH |
2395 | |
2396 | /* Load the list of CAs for which we will accept certs, for sending | |
2397 | to the client. This is only for the one-file tls_verify_certificates | |
2398 | variant. | |
d7978c0f JH |
2399 | If a list isn't loaded into the server, but some verify locations are set, |
2400 | the server end appears to make a wildcard request for client certs. | |
10a831a3 | 2401 | Meanwhile, the client library as default behaviour *ignores* the list |
cb1d7830 JH |
2402 | we send over the wire - see man SSL_CTX_set_client_cert_cb. |
2403 | Because of this, and that the dir variant is likely only used for | |
d7978c0f JH |
2404 | the public-CA bundle (not for a private CA), not worth fixing. */ |
2405 | ||
f2f2c91b | 2406 | if (file) |
cb1d7830 | 2407 | { |
2009ecca | 2408 | STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file); |
dec766a1 WB |
2409 | |
2410 | SSL_CTX_set_client_CA_list(sctx, names); | |
f2f2c91b | 2411 | DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", |
cb1d7830 | 2412 | sk_X509_NAME_num(names)); |
cb1d7830 | 2413 | } |
059ec3d9 PH |
2414 | } |
2415 | } | |
2416 | ||
2417 | /* Handle a certificate revocation list. */ | |
2418 | ||
10a831a3 | 2419 | #if OPENSSL_VERSION_NUMBER > 0x00907000L |
059ec3d9 | 2420 | |
8b417f2c | 2421 | /* This bit of code is now the version supplied by Lars Mainka. (I have |
10a831a3 | 2422 | merely reformatted it into the Exim code style.) |
8b417f2c | 2423 | |
10a831a3 JH |
2424 | "From here I changed the code to add support for multiple crl's |
2425 | in pem format in one file or to support hashed directory entries in | |
2426 | pem format instead of a file. This method now uses the library function | |
2427 | X509_STORE_load_locations to add the CRL location to the SSL context. | |
2428 | OpenSSL will then handle the verify against CA certs and CRLs by | |
2429 | itself in the verify callback." */ | |
8b417f2c | 2430 | |
cf0c6164 | 2431 | if (!expand_check(crl, US"tls_crl", &expcrl, errstr)) return DEFER; |
10a831a3 | 2432 | if (expcrl && *expcrl) |
059ec3d9 | 2433 | { |
8b417f2c PH |
2434 | struct stat statbufcrl; |
2435 | if (Ustat(expcrl, &statbufcrl) < 0) | |
2436 | { | |
2437 | log_write(0, LOG_MAIN|LOG_PANIC, | |
2438 | "failed to stat %s for certificates revocation lists", expcrl); | |
2439 | return DEFER; | |
2440 | } | |
2441 | else | |
059ec3d9 | 2442 | { |
8b417f2c PH |
2443 | /* is it a file or directory? */ |
2444 | uschar *file, *dir; | |
7be682ca | 2445 | X509_STORE *cvstore = SSL_CTX_get_cert_store(sctx); |
8b417f2c | 2446 | if ((statbufcrl.st_mode & S_IFMT) == S_IFDIR) |
059ec3d9 | 2447 | { |
8b417f2c PH |
2448 | file = NULL; |
2449 | dir = expcrl; | |
2450 | DEBUG(D_tls) debug_printf("SSL CRL value is a directory %s\n", dir); | |
059ec3d9 PH |
2451 | } |
2452 | else | |
2453 | { | |
8b417f2c PH |
2454 | file = expcrl; |
2455 | dir = NULL; | |
2456 | DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); | |
059ec3d9 | 2457 | } |
8b417f2c | 2458 | if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) |
cf0c6164 | 2459 | return tls_error(US"X509_STORE_load_locations", host, NULL, errstr); |
8b417f2c PH |
2460 | |
2461 | /* setting the flags to check against the complete crl chain */ | |
2462 | ||
2463 | X509_STORE_set_flags(cvstore, | |
2464 | X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL); | |
059ec3d9 | 2465 | } |
059ec3d9 PH |
2466 | } |
2467 | ||
10a831a3 | 2468 | #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ |
059ec3d9 PH |
2469 | |
2470 | /* If verification is optional, don't fail if no certificate */ | |
2471 | ||
7be682ca | 2472 | SSL_CTX_set_verify(sctx, |
5a2a0989 | 2473 | SSL_VERIFY_PEER | (optional ? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT), |
983207c1 | 2474 | cert_vfy_cb); |
059ec3d9 PH |
2475 | } |
2476 | ||
2477 | return OK; | |
2478 | } | |
2479 | ||
2480 | ||
2481 | ||
2482 | /************************************************* | |
2483 | * Start a TLS session in a server * | |
2484 | *************************************************/ | |
2485 | ||
2486 | /* This is called when Exim is running as a server, after having received | |
2487 | the STARTTLS command. It must respond to that command, and then negotiate | |
2488 | a TLS session. | |
2489 | ||
2490 | Arguments: | |
2491 | require_ciphers allowed ciphers | |
cf0c6164 | 2492 | errstr pointer to error message |
059ec3d9 PH |
2493 | |
2494 | Returns: OK on success | |
2495 | DEFER for errors before the start of the negotiation | |
4c04137d | 2496 | FAIL for errors during the negotiation; the server can't |
059ec3d9 PH |
2497 | continue running. |
2498 | */ | |
2499 | ||
2500 | int | |
cf0c6164 | 2501 | tls_server_start(const uschar * require_ciphers, uschar ** errstr) |
059ec3d9 PH |
2502 | { |
2503 | int rc; | |
cf0c6164 JH |
2504 | uschar * expciphers; |
2505 | tls_ext_ctx_cb * cbinfo; | |
f69979cf | 2506 | static uschar peerdn[256]; |
059ec3d9 PH |
2507 | |
2508 | /* Check for previous activation */ | |
2509 | ||
74f1a423 | 2510 | if (tls_in.active.sock >= 0) |
059ec3d9 | 2511 | { |
cf0c6164 | 2512 | tls_error(US"STARTTLS received after TLS started", NULL, US"", errstr); |
925ac8e4 | 2513 | smtp_printf("554 Already in TLS\r\n", FALSE); |
059ec3d9 PH |
2514 | return FAIL; |
2515 | } | |
2516 | ||
2517 | /* Initialize the SSL library. If it fails, it will already have logged | |
2518 | the error. */ | |
2519 | ||
817d9f57 | 2520 | rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey, |
f2de3a33 | 2521 | #ifndef DISABLE_OCSP |
5b2fd993 | 2522 | tls_ocsp_file, |
3f7eeb86 | 2523 | #endif |
b10c87b3 | 2524 | NULL, &server_static_cbinfo, &tls_in, errstr); |
059ec3d9 | 2525 | if (rc != OK) return rc; |
817d9f57 | 2526 | cbinfo = server_static_cbinfo; |
059ec3d9 | 2527 | |
cf0c6164 | 2528 | if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers, errstr)) |
059ec3d9 PH |
2529 | return FAIL; |
2530 | ||
2531 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
17c76198 PP |
2532 | were historically separated by underscores. So that I can use either form in my |
2533 | tests, and also for general convenience, we turn underscores into hyphens here. | |
0c3807a8 JH |
2534 | |
2535 | XXX SSL_CTX_set_cipher_list() is replaced by SSL_CTX_set_ciphersuites() | |
2536 | for TLS 1.3 . Since we do not call it at present we get the default list: | |
2537 | TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256 | |
17c76198 | 2538 | */ |
059ec3d9 | 2539 | |
c3033f13 | 2540 | if (expciphers) |
059ec3d9 | 2541 | { |
b10c87b3 | 2542 | for (uschar * s = expciphers; *s; s++ ) if (*s == '_') *s = '-'; |
059ec3d9 | 2543 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); |
817d9f57 | 2544 | if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) |
cf0c6164 | 2545 | return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL, errstr); |
7be682ca | 2546 | cbinfo->server_cipher_list = expciphers; |
059ec3d9 PH |
2547 | } |
2548 | ||
2549 | /* If this is a host for which certificate verification is mandatory or | |
2550 | optional, set up appropriately. */ | |
2551 | ||
817d9f57 | 2552 | tls_in.certificate_verified = FALSE; |
c0635b6d | 2553 | #ifdef SUPPORT_DANE |
53a7196b JH |
2554 | tls_in.dane_verified = FALSE; |
2555 | #endif | |
a2ff477a | 2556 | server_verify_callback_called = FALSE; |
059ec3d9 PH |
2557 | |
2558 | if (verify_check_host(&tls_verify_hosts) == OK) | |
2559 | { | |
983207c1 | 2560 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
afdb5e9c | 2561 | FALSE, verify_callback_server, errstr); |
059ec3d9 | 2562 | if (rc != OK) return rc; |
a2ff477a | 2563 | server_verify_optional = FALSE; |
059ec3d9 PH |
2564 | } |
2565 | else if (verify_check_host(&tls_try_verify_hosts) == OK) | |
2566 | { | |
983207c1 | 2567 | rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, |
afdb5e9c | 2568 | TRUE, verify_callback_server, errstr); |
059ec3d9 | 2569 | if (rc != OK) return rc; |
a2ff477a | 2570 | server_verify_optional = TRUE; |
059ec3d9 PH |
2571 | } |
2572 | ||
b10c87b3 JH |
2573 | #ifdef EXPERIMENTAL_TLS_RESUME |
2574 | SSL_CTX_set_tlsext_ticket_key_cb(server_ctx, ticket_key_callback); | |
2575 | /* despite working, appears to always return failure, so ignoring */ | |
2576 | #endif | |
2577 | #ifdef OPENSSL_HAVE_NUM_TICKETS | |
2578 | # ifdef EXPERIMENTAL_TLS_RESUME | |
2579 | SSL_CTX_set_num_tickets(server_ctx, tls_in.host_resumable ? 1 : 0); | |
2580 | # else | |
2581 | SSL_CTX_set_num_tickets(server_ctx, 0); /* send no TLS1.3 stateful-tickets */ | |
2582 | # endif | |
2583 | #endif | |
2584 | ||
2585 | ||
059ec3d9 PH |
2586 | /* Prepare for new connection */ |
2587 | ||
cf0c6164 JH |
2588 | if (!(server_ssl = SSL_new(server_ctx))) |
2589 | return tls_error(US"SSL_new", NULL, NULL, errstr); | |
da3ad30d PP |
2590 | |
2591 | /* Warning: we used to SSL_clear(ssl) here, it was removed. | |
2592 | * | |
2593 | * With the SSL_clear(), we get strange interoperability bugs with | |
2594 | * OpenSSL 1.0.1b and TLS1.1/1.2. It looks as though this may be a bug in | |
2595 | * OpenSSL itself, as a clear should not lead to inability to follow protocols. | |
2596 | * | |
2597 | * The SSL_clear() call is to let an existing SSL* be reused, typically after | |
2598 | * session shutdown. In this case, we have a brand new object and there's no | |
2599 | * obvious reason to immediately clear it. I'm guessing that this was | |
2600 | * originally added because of incomplete initialisation which the clear fixed, | |
2601 | * in some historic release. | |
2602 | */ | |
059ec3d9 PH |
2603 | |
2604 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
2605 | on connection, where outputting anything now upsets the clients and tends to | |
2606 | make them disconnect. We need to have an explicit fflush() here, to force out | |
2607 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
2608 | mode, the fflush() happens when smtp_getc() is called. */ | |
2609 | ||
817d9f57 JH |
2610 | SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx)); |
2611 | if (!tls_in.on_connect) | |
059ec3d9 | 2612 | { |
925ac8e4 | 2613 | smtp_printf("220 TLS go ahead\r\n", FALSE); |
059ec3d9 PH |
2614 | fflush(smtp_out); |
2615 | } | |
2616 | ||
2617 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
2618 | that the OpenSSL library doesn't. */ | |
2619 | ||
817d9f57 JH |
2620 | SSL_set_wfd(server_ssl, fileno(smtp_out)); |
2621 | SSL_set_rfd(server_ssl, fileno(smtp_in)); | |
2622 | SSL_set_accept_state(server_ssl); | |
059ec3d9 PH |
2623 | |
2624 | DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); | |
2625 | ||
2626 | sigalrm_seen = FALSE; | |
c2a1bba0 | 2627 | if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); |
817d9f57 | 2628 | rc = SSL_accept(server_ssl); |
c2a1bba0 | 2629 | ALARM_CLR(0); |
059ec3d9 PH |
2630 | |
2631 | if (rc <= 0) | |
2632 | { | |
c31e16a5 JH |
2633 | int error = SSL_get_error(server_ssl, rc); |
2634 | switch(error) | |
2635 | { | |
2636 | case SSL_ERROR_NONE: | |
2637 | break; | |
2638 | ||
2639 | case SSL_ERROR_ZERO_RETURN: | |
2640 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
2641 | (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr); | |
2642 | ||
2643 | if (SSL_get_shutdown(server_ssl) == SSL_RECEIVED_SHUTDOWN) | |
2644 | SSL_shutdown(server_ssl); | |
2645 | ||
2646 | tls_close(NULL, TLS_NO_SHUTDOWN); | |
2647 | return FAIL; | |
2648 | ||
2649 | /* Handle genuine errors */ | |
2650 | case SSL_ERROR_SSL: | |
2651 | (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr); | |
2652 | return FAIL; | |
2653 | ||
2654 | default: | |
2655 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
2656 | if (error == SSL_ERROR_SYSCALL) | |
2657 | { | |
2658 | if (!errno) | |
2659 | { | |
2660 | *errstr = US"SSL_accept: TCP connection closed by peer"; | |
2661 | return FAIL; | |
2662 | } | |
2663 | DEBUG(D_tls) debug_printf(" - syscall %s\n", strerror(errno)); | |
2664 | } | |
2665 | (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr); | |
2666 | return FAIL; | |
2667 | } | |
059ec3d9 PH |
2668 | } |
2669 | ||
2670 | DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); | |
25fa0868 | 2671 | ERR_clear_error(); /* Even success can leave errors in the stack. Seen with |
b10c87b3 JH |
2672 | anon-authentication ciphersuite negotiated. */ |
2673 | ||
2674 | #ifdef EXPERIMENTAL_TLS_RESUME | |
2675 | if (SSL_session_reused(server_ssl)) | |
2676 | { | |
2677 | tls_in.resumption |= RESUME_USED; | |
2678 | DEBUG(D_tls) debug_printf("Session reused\n"); | |
2679 | } | |
2680 | #endif | |
059ec3d9 PH |
2681 | |
2682 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
2683 | and initialize things. */ | |
2684 | ||
f69979cf JH |
2685 | peer_cert(server_ssl, &tls_in, peerdn, sizeof(peerdn)); |
2686 | ||
f1be21cf JH |
2687 | tls_in.cipher = construct_cipher_name(server_ssl, &tls_in.bits); |
2688 | tls_in.cipher_stdname = cipher_stdname_ssl(server_ssl); | |
2689 | ||
059ec3d9 PH |
2690 | DEBUG(D_tls) |
2691 | { | |
2692 | uschar buf[2048]; | |
f1be21cf | 2693 | if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf))) |
059ec3d9 | 2694 | debug_printf("Shared ciphers: %s\n", buf); |
f20cfa4a JH |
2695 | |
2696 | #ifdef EXIM_HAVE_OPENSSL_KEYLOG | |
2697 | { | |
10ed27e0 | 2698 | BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE); |
f20cfa4a | 2699 | SSL_SESSION_print_keylog(bp, SSL_get_session(server_ssl)); |
f20cfa4a JH |
2700 | BIO_free(bp); |
2701 | } | |
2702 | #endif | |
b10c87b3 JH |
2703 | |
2704 | #ifdef EXIM_HAVE_SESSION_TICKET | |
2705 | { | |
2706 | SSL_SESSION * ss = SSL_get_session(server_ssl); | |
40618fb6 | 2707 | if (SSL_SESSION_has_ticket(ss)) /* 1.1.0 */ |
b10c87b3 JH |
2708 | debug_printf("The session has a ticket, life %lu seconds\n", |
2709 | SSL_SESSION_get_ticket_lifetime_hint(ss)); | |
2710 | } | |
2711 | #endif | |
059ec3d9 PH |
2712 | } |
2713 | ||
9d1c15ef JH |
2714 | /* Record the certificate we presented */ |
2715 | { | |
2716 | X509 * crt = SSL_get_certificate(server_ssl); | |
2717 | tls_in.ourcert = crt ? X509_dup(crt) : NULL; | |
2718 | } | |
059ec3d9 | 2719 | |
817d9f57 JH |
2720 | /* Only used by the server-side tls (tls_in), including tls_getc. |
2721 | Client-side (tls_out) reads (seem to?) go via | |
2722 | smtp_read_response()/ip_recv(). | |
2723 | Hence no need to duplicate for _in and _out. | |
2724 | */ | |
b808677c | 2725 | if (!ssl_xfer_buffer) ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
059ec3d9 | 2726 | ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; |
8b77d27a | 2727 | ssl_xfer_eof = ssl_xfer_error = FALSE; |
059ec3d9 PH |
2728 | |
2729 | receive_getc = tls_getc; | |
0d81dabc | 2730 | receive_getbuf = tls_getbuf; |
584e96c6 | 2731 | receive_get_cache = tls_get_cache; |
059ec3d9 PH |
2732 | receive_ungetc = tls_ungetc; |
2733 | receive_feof = tls_feof; | |
2734 | receive_ferror = tls_ferror; | |
58eb016e | 2735 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 2736 | |
74f1a423 JH |
2737 | tls_in.active.sock = fileno(smtp_out); |
2738 | tls_in.active.tls_ctx = NULL; /* not using explicit ctx for server-side */ | |
059ec3d9 PH |
2739 | return OK; |
2740 | } | |
2741 | ||
2742 | ||
2743 | ||
2744 | ||
043b1248 JH |
2745 | static int |
2746 | tls_client_basic_ctx_init(SSL_CTX * ctx, | |
cf0c6164 JH |
2747 | host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo, |
2748 | uschar ** errstr) | |
043b1248 JH |
2749 | { |
2750 | int rc; | |
94431adb | 2751 | /* stick to the old behaviour for compatibility if tls_verify_certificates is |
043b1248 JH |
2752 | set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only |
2753 | the specified host patterns if one of them is defined */ | |
2754 | ||
610ff438 JH |
2755 | if ( ( !ob->tls_verify_hosts |
2756 | && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) | |
2757 | ) | |
3c07dd2d | 2758 | || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK |
aa2a70ba | 2759 | ) |
043b1248 | 2760 | client_verify_optional = FALSE; |
3c07dd2d | 2761 | else if (verify_check_given_host(CUSS &ob->tls_try_verify_hosts, host) == OK) |
aa2a70ba JH |
2762 | client_verify_optional = TRUE; |
2763 | else | |
2764 | return OK; | |
2765 | ||
2766 | if ((rc = setup_certs(ctx, ob->tls_verify_certificates, | |
cf0c6164 JH |
2767 | ob->tls_crl, host, client_verify_optional, verify_callback_client, |
2768 | errstr)) != OK) | |
aa2a70ba | 2769 | return rc; |
043b1248 | 2770 | |
3c07dd2d | 2771 | if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK) |
043b1248 | 2772 | { |
4af0d74a | 2773 | cbinfo->verify_cert_hostnames = |
8c5d388a | 2774 | #ifdef SUPPORT_I18N |
4af0d74a JH |
2775 | string_domain_utf8_to_alabel(host->name, NULL); |
2776 | #else | |
2777 | host->name; | |
2778 | #endif | |
aa2a70ba JH |
2779 | DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", |
2780 | cbinfo->verify_cert_hostnames); | |
043b1248 | 2781 | } |
043b1248 JH |
2782 | return OK; |
2783 | } | |
059ec3d9 | 2784 | |
fde080a4 | 2785 | |
c0635b6d | 2786 | #ifdef SUPPORT_DANE |
fde080a4 | 2787 | static int |
cf0c6164 | 2788 | dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa, uschar ** errstr) |
fde080a4 | 2789 | { |
fde080a4 JH |
2790 | dns_scan dnss; |
2791 | const char * hostnames[2] = { CS host->name, NULL }; | |
2792 | int found = 0; | |
2793 | ||
2794 | if (DANESSL_init(ssl, NULL, hostnames) != 1) | |
cf0c6164 | 2795 | return tls_error(US"hostnames load", host, NULL, errstr); |
fde080a4 | 2796 | |
d7978c0f | 2797 | for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; |
fde080a4 | 2798 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) |
1b76ad22 | 2799 | ) if (rr->type == T_TLSA && rr->size > 3) |
fde080a4 | 2800 | { |
c3033f13 | 2801 | const uschar * p = rr->data; |
fde080a4 JH |
2802 | uint8_t usage, selector, mtype; |
2803 | const char * mdname; | |
2804 | ||
fde080a4 | 2805 | usage = *p++; |
133d2546 JH |
2806 | |
2807 | /* Only DANE-TA(2) and DANE-EE(3) are supported */ | |
2808 | if (usage != 2 && usage != 3) continue; | |
2809 | ||
fde080a4 JH |
2810 | selector = *p++; |
2811 | mtype = *p++; | |
2812 | ||
2813 | switch (mtype) | |
2814 | { | |
133d2546 JH |
2815 | default: continue; /* Only match-types 0, 1, 2 are supported */ |
2816 | case 0: mdname = NULL; break; | |
2817 | case 1: mdname = "sha256"; break; | |
2818 | case 2: mdname = "sha512"; break; | |
fde080a4 JH |
2819 | } |
2820 | ||
133d2546 | 2821 | found++; |
fde080a4 JH |
2822 | switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3)) |
2823 | { | |
2824 | default: | |
cf0c6164 | 2825 | return tls_error(US"tlsa load", host, NULL, errstr); |
c035b645 | 2826 | case 0: /* action not taken */ |
fde080a4 JH |
2827 | case 1: break; |
2828 | } | |
594706ea JH |
2829 | |
2830 | tls_out.tlsa_usage |= 1<<usage; | |
fde080a4 JH |
2831 | } |
2832 | ||
2833 | if (found) | |
2834 | return OK; | |
2835 | ||
133d2546 | 2836 | log_write(0, LOG_MAIN, "DANE error: No usable TLSA records"); |
6ebd79ec | 2837 | return DEFER; |
fde080a4 | 2838 | } |
c0635b6d | 2839 | #endif /*SUPPORT_DANE*/ |
fde080a4 JH |
2840 | |
2841 | ||
2842 | ||
b10c87b3 JH |
2843 | #ifdef EXPERIMENTAL_TLS_RESUME |
2844 | /* On the client, get any stashed session for the given IP from hints db | |
2845 | and apply it to the ssl-connection for attempted resumption. */ | |
2846 | ||
2847 | static void | |
2848 | tls_retrieve_session(tls_support * tlsp, SSL * ssl, const uschar * key) | |
2849 | { | |
2850 | tlsp->resumption |= RESUME_SUPPORTED; | |
2851 | if (tlsp->host_resumable) | |
2852 | { | |
2853 | dbdata_tls_session * dt; | |
2854 | int len; | |
2855 | open_db dbblock, * dbm_file; | |
2856 | ||
2857 | tlsp->resumption |= RESUME_CLIENT_REQUESTED; | |
2858 | DEBUG(D_tls) debug_printf("checking for resumable session for %s\n", key); | |
2859 | if ((dbm_file = dbfn_open(US"tls", O_RDONLY, &dbblock, FALSE, FALSE))) | |
2860 | { | |
2861 | /* key for the db is the IP */ | |
2862 | if ((dt = dbfn_read_with_length(dbm_file, key, &len))) | |
2863 | { | |
2864 | SSL_SESSION * ss = NULL; | |
2865 | const uschar * sess_asn1 = dt->session; | |
2866 | ||
2867 | len -= sizeof(dbdata_tls_session); | |
2868 | if (!(d2i_SSL_SESSION(&ss, &sess_asn1, (long)len))) | |
2869 | { | |
2870 | DEBUG(D_tls) | |
2871 | { | |
2872 | ERR_error_string_n(ERR_get_error(), | |
2873 | ssl_errstring, sizeof(ssl_errstring)); | |
2874 | debug_printf("decoding session: %s\n", ssl_errstring); | |
2875 | } | |
2876 | } | |
a775dd1d | 2877 | #ifdef EXIM_HAVE_SESSION_TICKET |
4f1d23a1 JH |
2878 | else if ( SSL_SESSION_get_ticket_lifetime_hint(ss) + dt->time_stamp |
2879 | < time(NULL)) | |
2880 | { | |
2881 | DEBUG(D_tls) debug_printf("session expired\n"); | |
2882 | dbfn_delete(dbm_file, key); | |
2883 | } | |
a775dd1d | 2884 | #endif |
b10c87b3 JH |
2885 | else if (!SSL_set_session(ssl, ss)) |
2886 | { | |
2887 | DEBUG(D_tls) | |
2888 | { | |
2889 | ERR_error_string_n(ERR_get_error(), | |
2890 | ssl_errstring, sizeof(ssl_errstring)); | |
2891 | debug_printf("applying session to ssl: %s\n", ssl_errstring); | |
2892 | } | |
2893 | } | |
2894 | else | |
2895 | { | |
2896 | DEBUG(D_tls) debug_printf("good session\n"); | |
2897 | tlsp->resumption |= RESUME_CLIENT_SUGGESTED; | |
f4e62a87 | 2898 | tlsp->verify_override = dt->verify_override; |
c82de233 | 2899 | tlsp->ocsp = dt->ocsp; |
b10c87b3 JH |
2900 | } |
2901 | } | |
2902 | else | |
2903 | DEBUG(D_tls) debug_printf("no session record\n"); | |
2904 | dbfn_close(dbm_file); | |
2905 | } | |
2906 | } | |
2907 | } | |
2908 | ||
2909 | ||
2910 | /* On the client, save the session for later resumption */ | |
2911 | ||
2912 | static int | |
2913 | tls_save_session_cb(SSL * ssl, SSL_SESSION * ss) | |
2914 | { | |
2915 | tls_ext_ctx_cb * cbinfo = SSL_get_ex_data(ssl, tls_exdata_idx); | |
2916 | tls_support * tlsp; | |
2917 | ||
2918 | DEBUG(D_tls) debug_printf("tls_save_session_cb\n"); | |
2919 | ||
2920 | if (!cbinfo || !(tlsp = cbinfo->tlsp)->host_resumable) return 0; | |
2921 | ||
40618fb6 JH |
2922 | # ifdef OPENSSL_HAVE_NUM_TICKETS |
2923 | if (SSL_SESSION_is_resumable(ss)) /* 1.1.1 */ | |
2924 | # endif | |
b10c87b3 JH |
2925 | { |
2926 | int len = i2d_SSL_SESSION(ss, NULL); | |
2927 | int dlen = sizeof(dbdata_tls_session) + len; | |
f3ebb786 | 2928 | dbdata_tls_session * dt = store_get(dlen, TRUE); |
b10c87b3 JH |
2929 | uschar * s = dt->session; |
2930 | open_db dbblock, * dbm_file; | |
2931 | ||
2932 | DEBUG(D_tls) debug_printf("session is resumable\n"); | |
2933 | tlsp->resumption |= RESUME_SERVER_TICKET; /* server gave us a ticket */ | |
2934 | ||
f4e62a87 | 2935 | dt->verify_override = tlsp->verify_override; |
c82de233 | 2936 | dt->ocsp = tlsp->ocsp; |
f4e62a87 | 2937 | (void) i2d_SSL_SESSION(ss, &s); /* s gets bumped to end */ |
b10c87b3 JH |
2938 | |
2939 | if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE))) | |
2940 | { | |
2941 | const uschar * key = cbinfo->host->address; | |
2942 | dbfn_delete(dbm_file, key); | |
2943 | dbfn_write(dbm_file, key, dt, dlen); | |
2944 | dbfn_close(dbm_file); | |
2945 | DEBUG(D_tls) debug_printf("wrote session (len %u) to db\n", | |
2946 | (unsigned)dlen); | |
2947 | } | |
2948 | } | |
b10c87b3 JH |
2949 | return 1; |
2950 | } | |
2951 | ||
2952 | ||
2953 | static void | |
2954 | tls_client_ctx_resume_prehandshake( | |
2955 | exim_openssl_client_tls_ctx * exim_client_ctx, tls_support * tlsp, | |
2956 | smtp_transport_options_block * ob, host_item * host) | |
2957 | { | |
2958 | /* Should the client request a session resumption ticket? */ | |
2959 | if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, host) == OK) | |
2960 | { | |
2961 | tlsp->host_resumable = TRUE; | |
2962 | ||
2963 | SSL_CTX_set_session_cache_mode(exim_client_ctx->ctx, | |
2964 | SSL_SESS_CACHE_CLIENT | |
2965 | | SSL_SESS_CACHE_NO_INTERNAL | SSL_SESS_CACHE_NO_AUTO_CLEAR); | |
2966 | SSL_CTX_sess_set_new_cb(exim_client_ctx->ctx, tls_save_session_cb); | |
2967 | } | |
2968 | } | |
2969 | ||
2970 | static BOOL | |
2971 | tls_client_ssl_resume_prehandshake(SSL * ssl, tls_support * tlsp, | |
2972 | host_item * host, uschar ** errstr) | |
2973 | { | |
2974 | if (tlsp->host_resumable) | |
2975 | { | |
2976 | DEBUG(D_tls) | |
2977 | debug_printf("tls_resumption_hosts overrides openssl_options, enabling tickets\n"); | |
2978 | SSL_clear_options(ssl, SSL_OP_NO_TICKET); | |
2979 | ||
2980 | tls_exdata_idx = SSL_get_ex_new_index(0, 0, 0, 0, 0); | |
2981 | if (!SSL_set_ex_data(ssl, tls_exdata_idx, client_static_cbinfo)) | |
2982 | { | |
2983 | tls_error(US"set ex_data", host, NULL, errstr); | |
2984 | return FALSE; | |
2985 | } | |
2986 | debug_printf("tls_exdata_idx %d cbinfo %p\n", tls_exdata_idx, client_static_cbinfo); | |
2987 | } | |
2988 | ||
2989 | tlsp->resumption = RESUME_SUPPORTED; | |
2990 | /* Pick up a previous session, saved on an old ticket */ | |
2991 | tls_retrieve_session(tlsp, ssl, host->address); | |
2992 | return TRUE; | |
2993 | } | |
2994 | ||
2995 | static void | |
2996 | tls_client_resume_posthandshake(exim_openssl_client_tls_ctx * exim_client_ctx, | |
2997 | tls_support * tlsp) | |
2998 | { | |
2999 | if (SSL_session_reused(exim_client_ctx->ssl)) | |
3000 | { | |
3001 | DEBUG(D_tls) debug_printf("The session was reused\n"); | |
3002 | tlsp->resumption |= RESUME_USED; | |
3003 | } | |
3004 | } | |
3005 | #endif /* EXPERIMENTAL_TLS_RESUME */ | |
3006 | ||
3007 | ||
059ec3d9 PH |
3008 | /************************************************* |
3009 | * Start a TLS session in a client * | |
3010 | *************************************************/ | |
3011 | ||
3012 | /* Called from the smtp transport after STARTTLS has been accepted. | |
3013 | ||
c05bdbd6 JH |
3014 | Arguments: |
3015 | cctx connection context | |
3016 | conn_args connection details | |
3017 | cookie datum for randomness; can be NULL | |
3018 | tlsp record details of TLS channel configuration here; must be non-NULL | |
3019 | errstr error string pointer | |
3020 | ||
3021 | Returns: TRUE for success with TLS session context set in connection context, | |
3022 | FALSE on error | |
059ec3d9 PH |
3023 | */ |
3024 | ||
c05bdbd6 JH |
3025 | BOOL |
3026 | tls_client_start(client_conn_ctx * cctx, smtp_connect_args * conn_args, | |
3027 | void * cookie, tls_support * tlsp, uschar ** errstr) | |
059ec3d9 | 3028 | { |
c05bdbd6 JH |
3029 | host_item * host = conn_args->host; /* for msgs and option-tests */ |
3030 | transport_instance * tb = conn_args->tblock; /* always smtp or NULL */ | |
afdb5e9c JH |
3031 | smtp_transport_options_block * ob = tb |
3032 | ? (smtp_transport_options_block *)tb->options_block | |
3033 | : &smtp_transport_option_defaults; | |
74f1a423 | 3034 | exim_openssl_client_tls_ctx * exim_client_ctx; |
868f5672 | 3035 | uschar * expciphers; |
059ec3d9 | 3036 | int rc; |
c05bdbd6 | 3037 | static uschar peerdn[256]; |
043b1248 JH |
3038 | |
3039 | #ifndef DISABLE_OCSP | |
043b1248 | 3040 | BOOL request_ocsp = FALSE; |
6634ac8d | 3041 | BOOL require_ocsp = FALSE; |
043b1248 | 3042 | #endif |
043b1248 | 3043 | |
74f1a423 JH |
3044 | rc = store_pool; |
3045 | store_pool = POOL_PERM; | |
f3ebb786 | 3046 | exim_client_ctx = store_get(sizeof(exim_openssl_client_tls_ctx), FALSE); |
c09dbcfb | 3047 | exim_client_ctx->corked = NULL; |
74f1a423 JH |
3048 | store_pool = rc; |
3049 | ||
c0635b6d | 3050 | #ifdef SUPPORT_DANE |
74f1a423 | 3051 | tlsp->tlsa_usage = 0; |
043b1248 JH |
3052 | #endif |
3053 | ||
f2de3a33 | 3054 | #ifndef DISABLE_OCSP |
043b1248 | 3055 | { |
c0635b6d | 3056 | # ifdef SUPPORT_DANE |
c05bdbd6 | 3057 | if ( conn_args->dane |
4f59c424 JH |
3058 | && ob->hosts_request_ocsp[0] == '*' |
3059 | && ob->hosts_request_ocsp[1] == '\0' | |
3060 | ) | |
3061 | { | |
3062 | /* Unchanged from default. Use a safer one under DANE */ | |
3063 | request_ocsp = TRUE; | |
3064 | ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} " | |
3065 | " {= {4}{$tls_out_tlsa_usage}} } " | |
3066 | " {*}{}}"; | |
3067 | } | |
3068 | # endif | |
3069 | ||
5130845b | 3070 | if ((require_ocsp = |
3c07dd2d | 3071 | verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK)) |
fca41d5a JH |
3072 | request_ocsp = TRUE; |
3073 | else | |
c0635b6d | 3074 | # ifdef SUPPORT_DANE |
4f59c424 | 3075 | if (!request_ocsp) |
fca41d5a | 3076 | # endif |
5130845b | 3077 | request_ocsp = |
3c07dd2d | 3078 | verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK; |
043b1248 | 3079 | } |
f5d78688 | 3080 | #endif |
059ec3d9 | 3081 | |
74f1a423 | 3082 | rc = tls_init(&exim_client_ctx->ctx, host, NULL, |
65867078 | 3083 | ob->tls_certificate, ob->tls_privatekey, |
f2de3a33 | 3084 | #ifndef DISABLE_OCSP |
44662487 | 3085 | (void *)(long)request_ocsp, |
3f7eeb86 | 3086 | #endif |
b10c87b3 | 3087 | cookie, &client_static_cbinfo, tlsp, errstr); |
c05bdbd6 | 3088 | if (rc != OK) return FALSE; |
059ec3d9 | 3089 | |
74f1a423 | 3090 | tlsp->certificate_verified = FALSE; |
a2ff477a | 3091 | client_verify_callback_called = FALSE; |
059ec3d9 | 3092 | |
5ec37a55 PP |
3093 | expciphers = NULL; |
3094 | #ifdef SUPPORT_DANE | |
c05bdbd6 | 3095 | if (conn_args->dane) |
5ec37a55 PP |
3096 | { |
3097 | /* We fall back to tls_require_ciphers if unset, empty or forced failure, but | |
3098 | other failures should be treated as problems. */ | |
3099 | if (ob->dane_require_tls_ciphers && | |
3100 | !expand_check(ob->dane_require_tls_ciphers, US"dane_require_tls_ciphers", | |
3101 | &expciphers, errstr)) | |
c05bdbd6 | 3102 | return FALSE; |
5ec37a55 PP |
3103 | if (expciphers && *expciphers == '\0') |
3104 | expciphers = NULL; | |
3105 | } | |
3106 | #endif | |
3107 | if (!expciphers && | |
3108 | !expand_check(ob->tls_require_ciphers, US"tls_require_ciphers", | |
3109 | &expciphers, errstr)) | |
c05bdbd6 | 3110 | return FALSE; |
059ec3d9 PH |
3111 | |
3112 | /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they | |
3113 | are separated by underscores. So that I can use either form in my tests, and | |
3114 | also for general convenience, we turn underscores into hyphens here. */ | |
3115 | ||
cf0c6164 | 3116 | if (expciphers) |
059ec3d9 PH |
3117 | { |
3118 | uschar *s = expciphers; | |
cf0c6164 | 3119 | while (*s) { if (*s == '_') *s = '-'; s++; } |
059ec3d9 | 3120 | DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); |
74f1a423 JH |
3121 | if (!SSL_CTX_set_cipher_list(exim_client_ctx->ctx, CS expciphers)) |
3122 | { | |
3123 | tls_error(US"SSL_CTX_set_cipher_list", host, NULL, errstr); | |
c05bdbd6 | 3124 | return FALSE; |
74f1a423 | 3125 | } |
059ec3d9 PH |
3126 | } |
3127 | ||
c0635b6d | 3128 | #ifdef SUPPORT_DANE |
c05bdbd6 | 3129 | if (conn_args->dane) |
a63be306 | 3130 | { |
74f1a423 | 3131 | SSL_CTX_set_verify(exim_client_ctx->ctx, |
02af313d JH |
3132 | SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, |
3133 | verify_callback_client_dane); | |
e5cccda9 | 3134 | |
043b1248 | 3135 | if (!DANESSL_library_init()) |
74f1a423 JH |
3136 | { |
3137 | tls_error(US"library init", host, NULL, errstr); | |
c05bdbd6 | 3138 | return FALSE; |
74f1a423 JH |
3139 | } |
3140 | if (DANESSL_CTX_init(exim_client_ctx->ctx) <= 0) | |
3141 | { | |
3142 | tls_error(US"context init", host, NULL, errstr); | |
c05bdbd6 | 3143 | return FALSE; |
74f1a423 | 3144 | } |
043b1248 JH |
3145 | } |
3146 | else | |
e51c7be2 | 3147 | |
043b1248 JH |
3148 | #endif |
3149 | ||
74f1a423 JH |
3150 | if (tls_client_basic_ctx_init(exim_client_ctx->ctx, host, ob, |
3151 | client_static_cbinfo, errstr) != OK) | |
c05bdbd6 | 3152 | return FALSE; |
059ec3d9 | 3153 | |
b10c87b3 JH |
3154 | #ifdef EXPERIMENTAL_TLS_RESUME |
3155 | tls_client_ctx_resume_prehandshake(exim_client_ctx, tlsp, ob, host); | |
3156 | #endif | |
3157 | ||
3158 | ||
74f1a423 JH |
3159 | if (!(exim_client_ctx->ssl = SSL_new(exim_client_ctx->ctx))) |
3160 | { | |
3161 | tls_error(US"SSL_new", host, NULL, errstr); | |
c05bdbd6 | 3162 | return FALSE; |
74f1a423 JH |
3163 | } |
3164 | SSL_set_session_id_context(exim_client_ctx->ssl, sid_ctx, Ustrlen(sid_ctx)); | |
b10c87b3 | 3165 | |
c05bdbd6 | 3166 | SSL_set_fd(exim_client_ctx->ssl, cctx->sock); |
74f1a423 | 3167 | SSL_set_connect_state(exim_client_ctx->ssl); |
059ec3d9 | 3168 | |
65867078 | 3169 | if (ob->tls_sni) |
3f0945ff | 3170 | { |
74f1a423 | 3171 | if (!expand_check(ob->tls_sni, US"tls_sni", &tlsp->sni, errstr)) |
c05bdbd6 | 3172 | return FALSE; |
74f1a423 | 3173 | if (!tlsp->sni) |
2c9a0e86 PP |
3174 | { |
3175 | DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n"); | |
3176 | } | |
74f1a423 JH |
3177 | else if (!Ustrlen(tlsp->sni)) |
3178 | tlsp->sni = NULL; | |
3f0945ff PP |
3179 | else |
3180 | { | |
35731706 | 3181 | #ifdef EXIM_HAVE_OPENSSL_TLSEXT |
74f1a423 JH |
3182 | DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tlsp->sni); |
3183 | SSL_set_tlsext_host_name(exim_client_ctx->ssl, tlsp->sni); | |
35731706 | 3184 | #else |
66802652 | 3185 | log_write(0, LOG_MAIN, "SNI unusable with this OpenSSL library version; ignoring \"%s\"\n", |
74f1a423 | 3186 | tlsp->sni); |
35731706 | 3187 | #endif |
3f0945ff PP |
3188 | } |
3189 | } | |
3190 | ||
c0635b6d | 3191 | #ifdef SUPPORT_DANE |
c05bdbd6 JH |
3192 | if (conn_args->dane) |
3193 | if (dane_tlsa_load(exim_client_ctx->ssl, host, &conn_args->tlsa_dnsa, errstr) != OK) | |
3194 | return FALSE; | |
594706ea JH |
3195 | #endif |
3196 | ||
f2de3a33 | 3197 | #ifndef DISABLE_OCSP |
f5d78688 JH |
3198 | /* Request certificate status at connection-time. If the server |
3199 | does OCSP stapling we will get the callback (set in tls_init()) */ | |
c0635b6d | 3200 | # ifdef SUPPORT_DANE |
594706ea JH |
3201 | if (request_ocsp) |
3202 | { | |
3203 | const uschar * s; | |
41afb5cb JH |
3204 | if ( ((s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage")) |
3205 | || ((s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage")) | |
594706ea JH |
3206 | ) |
3207 | { /* Re-eval now $tls_out_tlsa_usage is populated. If | |
3208 | this means we avoid the OCSP request, we wasted the setup | |
3209 | cost in tls_init(). */ | |
3c07dd2d | 3210 | require_ocsp = verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK; |
5130845b | 3211 | request_ocsp = require_ocsp |
3c07dd2d | 3212 | || verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK; |
594706ea JH |
3213 | } |
3214 | } | |
b50c8b84 JH |
3215 | # endif |
3216 | ||
44662487 JH |
3217 | if (request_ocsp) |
3218 | { | |
74f1a423 | 3219 | SSL_set_tlsext_status_type(exim_client_ctx->ssl, TLSEXT_STATUSTYPE_ocsp); |
44662487 | 3220 | client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp; |
74f1a423 | 3221 | tlsp->ocsp = OCSP_NOT_RESP; |
44662487 | 3222 | } |
f5d78688 JH |
3223 | #endif |
3224 | ||
c82de233 JH |
3225 | #ifdef EXPERIMENTAL_TLS_RESUME |
3226 | if (!tls_client_ssl_resume_prehandshake(exim_client_ctx->ssl, tlsp, host, | |
3227 | errstr)) | |
3228 | return FALSE; | |
3229 | #endif | |
3230 | ||
0cbf2b82 | 3231 | #ifndef DISABLE_EVENT |
afdb5e9c | 3232 | client_static_cbinfo->event_action = tb ? tb->event_action : NULL; |
a7538db1 | 3233 | #endif |
043b1248 | 3234 | |
059ec3d9 PH |
3235 | /* There doesn't seem to be a built-in timeout on connection. */ |
3236 | ||
3237 | DEBUG(D_tls) debug_printf("Calling SSL_connect\n"); | |
3238 | sigalrm_seen = FALSE; | |
c2a1bba0 | 3239 | ALARM(ob->command_timeout); |
74f1a423 | 3240 | rc = SSL_connect(exim_client_ctx->ssl); |
c2a1bba0 | 3241 | ALARM_CLR(0); |
059ec3d9 | 3242 | |
c0635b6d | 3243 | #ifdef SUPPORT_DANE |
c05bdbd6 | 3244 | if (conn_args->dane) |
74f1a423 | 3245 | DANESSL_cleanup(exim_client_ctx->ssl); |
043b1248 JH |
3246 | #endif |
3247 | ||
059ec3d9 | 3248 | if (rc <= 0) |
74f1a423 JH |
3249 | { |
3250 | tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL, errstr); | |
c05bdbd6 | 3251 | return FALSE; |
74f1a423 | 3252 | } |
059ec3d9 | 3253 | |
f20cfa4a JH |
3254 | DEBUG(D_tls) |
3255 | { | |
3256 | debug_printf("SSL_connect succeeded\n"); | |
3257 | #ifdef EXIM_HAVE_OPENSSL_KEYLOG | |
3258 | { | |
10ed27e0 JH |
3259 | BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE); |
3260 | SSL_SESSION_print_keylog(bp, SSL_get_session(exim_client_ctx->ssl)); | |
3261 | BIO_free(bp); | |
f20cfa4a JH |
3262 | } |
3263 | #endif | |
3264 | } | |
059ec3d9 | 3265 | |
b10c87b3 JH |
3266 | #ifdef EXPERIMENTAL_TLS_RESUME |
3267 | tls_client_resume_posthandshake(exim_client_ctx, tlsp); | |
3268 | #endif | |
3269 | ||
74f1a423 | 3270 | peer_cert(exim_client_ctx->ssl, tlsp, peerdn, sizeof(peerdn)); |
059ec3d9 | 3271 | |
f1be21cf JH |
3272 | tlsp->cipher = construct_cipher_name(exim_client_ctx->ssl, &tlsp->bits); |
3273 | tlsp->cipher_stdname = cipher_stdname_ssl(exim_client_ctx->ssl); | |
059ec3d9 | 3274 | |
9d1c15ef JH |
3275 | /* Record the certificate we presented */ |
3276 | { | |
74f1a423 JH |
3277 | X509 * crt = SSL_get_certificate(exim_client_ctx->ssl); |
3278 | tlsp->ourcert = crt ? X509_dup(crt) : NULL; | |
9d1c15ef JH |
3279 | } |
3280 | ||
c05bdbd6 | 3281 | tlsp->active.sock = cctx->sock; |
74f1a423 | 3282 | tlsp->active.tls_ctx = exim_client_ctx; |
c05bdbd6 JH |
3283 | cctx->tls_ctx = exim_client_ctx; |
3284 | return TRUE; | |
059ec3d9 PH |
3285 | } |
3286 | ||
3287 | ||
3288 | ||
3289 | ||
3290 | ||
0d81dabc JH |
3291 | static BOOL |
3292 | tls_refill(unsigned lim) | |
3293 | { | |
3294 | int error; | |
3295 | int inbytes; | |
3296 | ||
3297 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl, | |
3298 | ssl_xfer_buffer, ssl_xfer_buffer_size); | |
3299 | ||
c2a1bba0 | 3300 | if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); |
0d81dabc JH |
3301 | inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, |
3302 | MIN(ssl_xfer_buffer_size, lim)); | |
3303 | error = SSL_get_error(server_ssl, inbytes); | |
c2a1bba0 | 3304 | if (smtp_receive_timeout > 0) ALARM_CLR(0); |
9723f966 JH |
3305 | |
3306 | if (had_command_timeout) /* set by signal handler */ | |
3307 | smtp_command_timeout_exit(); /* does not return */ | |
3308 | if (had_command_sigterm) | |
3309 | smtp_command_sigterm_exit(); | |
3310 | if (had_data_timeout) | |
3311 | smtp_data_timeout_exit(); | |
3312 | if (had_data_sigint) | |
3313 | smtp_data_sigint_exit(); | |
0d81dabc JH |
3314 | |
3315 | /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been | |
3316 | closed down, not that the socket itself has been closed down. Revert to | |
3317 | non-SSL handling. */ | |
3318 | ||
74f1a423 | 3319 | switch(error) |
0d81dabc | 3320 | { |
74f1a423 JH |
3321 | case SSL_ERROR_NONE: |
3322 | break; | |
3323 | ||
3324 | case SSL_ERROR_ZERO_RETURN: | |
3325 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
0d81dabc | 3326 | |
74f1a423 JH |
3327 | if (SSL_get_shutdown(server_ssl) == SSL_RECEIVED_SHUTDOWN) |
3328 | SSL_shutdown(server_ssl); | |
dec766a1 | 3329 | |
bd231acd | 3330 | tls_close(NULL, TLS_NO_SHUTDOWN); |
74f1a423 | 3331 | return FALSE; |
0d81dabc | 3332 | |
74f1a423 JH |
3333 | /* Handle genuine errors */ |
3334 | case SSL_ERROR_SSL: | |
0abc5a13 | 3335 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
74f1a423 JH |
3336 | log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); |
3337 | ssl_xfer_error = TRUE; | |
3338 | return FALSE; | |
0d81dabc | 3339 | |
74f1a423 JH |
3340 | default: |
3341 | DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); | |
3342 | DEBUG(D_tls) if (error == SSL_ERROR_SYSCALL) | |
3343 | debug_printf(" - syscall %s\n", strerror(errno)); | |
3344 | ssl_xfer_error = TRUE; | |
3345 | return FALSE; | |
0d81dabc JH |
3346 | } |
3347 | ||
3348 | #ifndef DISABLE_DKIM | |
3349 | dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); | |
3350 | #endif | |
3351 | ssl_xfer_buffer_hwm = inbytes; | |
3352 | ssl_xfer_buffer_lwm = 0; | |
3353 | return TRUE; | |
3354 | } | |
3355 | ||
3356 | ||
059ec3d9 PH |
3357 | /************************************************* |
3358 | * TLS version of getc * | |
3359 | *************************************************/ | |
3360 | ||
3361 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
3362 | it refills the buffer via the SSL reading function. | |
3363 | ||
bd8fbe36 | 3364 | Arguments: lim Maximum amount to read/buffer |
059ec3d9 | 3365 | Returns: the next character or EOF |
817d9f57 JH |
3366 | |
3367 | Only used by the server-side TLS. | |
059ec3d9 PH |
3368 | */ |
3369 | ||
3370 | int | |
bd8fbe36 | 3371 | tls_getc(unsigned lim) |
059ec3d9 PH |
3372 | { |
3373 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) | |
0d81dabc JH |
3374 | if (!tls_refill(lim)) |
3375 | return ssl_xfer_error ? EOF : smtp_getc(lim); | |
059ec3d9 | 3376 | |
0d81dabc | 3377 | /* Something in the buffer; return next uschar */ |
059ec3d9 | 3378 | |
0d81dabc JH |
3379 | return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; |
3380 | } | |
059ec3d9 | 3381 | |
0d81dabc JH |
3382 | uschar * |
3383 | tls_getbuf(unsigned * len) | |
3384 | { | |
3385 | unsigned size; | |
3386 | uschar * buf; | |
ba084640 | 3387 | |
0d81dabc JH |
3388 | if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) |
3389 | if (!tls_refill(*len)) | |
059ec3d9 | 3390 | { |
0d81dabc JH |
3391 | if (!ssl_xfer_error) return smtp_getbuf(len); |
3392 | *len = 0; | |
3393 | return NULL; | |
059ec3d9 | 3394 | } |
c80c5570 | 3395 | |
0d81dabc JH |
3396 | if ((size = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm) > *len) |
3397 | size = *len; | |
3398 | buf = &ssl_xfer_buffer[ssl_xfer_buffer_lwm]; | |
3399 | ssl_xfer_buffer_lwm += size; | |
3400 | *len = size; | |
3401 | return buf; | |
059ec3d9 PH |
3402 | } |
3403 | ||
0d81dabc | 3404 | |
584e96c6 JH |
3405 | void |
3406 | tls_get_cache() | |
3407 | { | |
9960d1e5 | 3408 | #ifndef DISABLE_DKIM |
584e96c6 JH |
3409 | int n = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm; |
3410 | if (n > 0) | |
3411 | dkim_exim_verify_feed(ssl_xfer_buffer+ssl_xfer_buffer_lwm, n); | |
584e96c6 | 3412 | #endif |
9960d1e5 | 3413 | } |
584e96c6 | 3414 | |
059ec3d9 | 3415 | |
925ac8e4 JH |
3416 | BOOL |
3417 | tls_could_read(void) | |
3418 | { | |
a5ffa9b4 | 3419 | return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm || SSL_pending(server_ssl) > 0; |
925ac8e4 JH |
3420 | } |
3421 | ||
059ec3d9 PH |
3422 | |
3423 | /************************************************* | |
3424 | * Read bytes from TLS channel * | |
3425 | *************************************************/ | |
3426 | ||
3427 | /* | |
3428 | Arguments: | |
74f1a423 | 3429 | ct_ctx client context pointer, or NULL for the one global server context |
059ec3d9 PH |
3430 | buff buffer of data |
3431 | len size of buffer | |
3432 | ||
3433 | Returns: the number of bytes read | |
afdb5e9c | 3434 | -1 after a failed read, including EOF |
817d9f57 JH |
3435 | |
3436 | Only used by the client-side TLS. | |
059ec3d9 PH |
3437 | */ |
3438 | ||
3439 | int | |
74f1a423 | 3440 | tls_read(void * ct_ctx, uschar *buff, size_t len) |
059ec3d9 | 3441 | { |
74f1a423 | 3442 | SSL * ssl = ct_ctx ? ((exim_openssl_client_tls_ctx *)ct_ctx)->ssl : server_ssl; |
059ec3d9 PH |
3443 | int inbytes; |
3444 | int error; | |
3445 | ||
389ca47a | 3446 | DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl, |
c80c5570 | 3447 | buff, (unsigned int)len); |
059ec3d9 | 3448 | |
389ca47a JH |
3449 | inbytes = SSL_read(ssl, CS buff, len); |
3450 | error = SSL_get_error(ssl, inbytes); | |
059ec3d9 PH |
3451 | |
3452 | if (error == SSL_ERROR_ZERO_RETURN) | |
3453 | { | |
3454 | DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); | |
3455 | return -1; | |
3456 | } | |
3457 | else if (error != SSL_ERROR_NONE) | |
059ec3d9 | 3458 | return -1; |
059ec3d9 PH |
3459 | |
3460 | return inbytes; | |
3461 | } | |
3462 | ||
3463 | ||
3464 | ||
3465 | ||
3466 | ||
3467 | /************************************************* | |
3468 | * Write bytes down TLS channel * | |
3469 | *************************************************/ | |
3470 | ||
3471 | /* | |
3472 | Arguments: | |
74f1a423 | 3473 | ct_ctx client context pointer, or NULL for the one global server context |
059ec3d9 PH |
3474 | buff buffer of data |
3475 | len number of bytes | |
925ac8e4 | 3476 | more further data expected soon |
059ec3d9 PH |
3477 | |
3478 | Returns: the number of bytes after a successful write, | |
3479 | -1 after a failed write | |
817d9f57 JH |
3480 | |
3481 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
3482 | */ |
3483 | ||
3484 | int | |
74f1a423 | 3485 | tls_write(void * ct_ctx, const uschar *buff, size_t len, BOOL more) |
059ec3d9 | 3486 | { |
ac35befe | 3487 | size_t olen = len; |
d7978c0f | 3488 | int outbytes, error; |
c09dbcfb JH |
3489 | SSL * ssl = ct_ctx |
3490 | ? ((exim_openssl_client_tls_ctx *)ct_ctx)->ssl : server_ssl; | |
3491 | static gstring * server_corked = NULL; | |
3492 | gstring ** corkedp = ct_ctx | |
3493 | ? &((exim_openssl_client_tls_ctx *)ct_ctx)->corked : &server_corked; | |
3494 | gstring * corked = *corkedp; | |
a5ffa9b4 | 3495 | |
ef698bf6 | 3496 | DEBUG(D_tls) debug_printf("%s(%p, %lu%s)\n", __FUNCTION__, |
b93be52e | 3497 | buff, (unsigned long)len, more ? ", more" : ""); |
a5ffa9b4 JH |
3498 | |
3499 | /* Lacking a CORK or MSG_MORE facility (such as GnuTLS has) we copy data when | |
3500 | "more" is notified. This hack is only ok if small amounts are involved AND only | |
3501 | one stream does it, in one context (i.e. no store reset). Currently it is used | |
c09dbcfb JH |
3502 | for the responses to the received SMTP MAIL , RCPT, DATA sequence, only. |
3503 | We support callouts done by the server process by using a separate client | |
3504 | context for the stashed information. */ | |
ac35befe JH |
3505 | /* + if PIPE_COMMAND, banner & ehlo-resp for smmtp-on-connect. Suspect there's |
3506 | a store reset there, so use POOL_PERM. */ | |
3507 | /* + if CHUNKING, cmds EHLO,MAIL,RCPT(s),BDAT */ | |
a5ffa9b4 | 3508 | |
ac35befe | 3509 | if ((more || corked)) |
a5ffa9b4 | 3510 | { |
4e48d56c | 3511 | #ifdef SUPPORT_PIPE_CONNECT |
ee8b8090 JH |
3512 | int save_pool = store_pool; |
3513 | store_pool = POOL_PERM; | |
3514 | #endif | |
3515 | ||
acec9514 | 3516 | corked = string_catn(corked, buff, len); |
ee8b8090 | 3517 | |
4e48d56c | 3518 | #ifdef SUPPORT_PIPE_CONNECT |
ee8b8090 JH |
3519 | store_pool = save_pool; |
3520 | #endif | |
3521 | ||
a5ffa9b4 | 3522 | if (more) |
c09dbcfb JH |
3523 | { |
3524 | *corkedp = corked; | |
a5ffa9b4 | 3525 | return len; |
c09dbcfb | 3526 | } |
acec9514 JH |
3527 | buff = CUS corked->s; |
3528 | len = corked->ptr; | |
c09dbcfb | 3529 | *corkedp = NULL; |
a5ffa9b4 | 3530 | } |
059ec3d9 | 3531 | |
d7978c0f | 3532 | for (int left = len; left > 0;) |
059ec3d9 | 3533 | { |
74f1a423 | 3534 | DEBUG(D_tls) debug_printf("SSL_write(%p, %p, %d)\n", ssl, buff, left); |
059ec3d9 PH |
3535 | outbytes = SSL_write(ssl, CS buff, left); |
3536 | error = SSL_get_error(ssl, outbytes); | |
3537 | DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error); | |
3538 | switch (error) | |
3539 | { | |
3540 | case SSL_ERROR_SSL: | |
0abc5a13 | 3541 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
96f5fe4c JH |
3542 | log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); |
3543 | return -1; | |
059ec3d9 PH |
3544 | |
3545 | case SSL_ERROR_NONE: | |
96f5fe4c JH |
3546 | left -= outbytes; |
3547 | buff += outbytes; | |
3548 | break; | |
059ec3d9 PH |
3549 | |
3550 | case SSL_ERROR_ZERO_RETURN: | |
96f5fe4c JH |
3551 | log_write(0, LOG_MAIN, "SSL channel closed on write"); |
3552 | return -1; | |
059ec3d9 | 3553 | |
817d9f57 | 3554 | case SSL_ERROR_SYSCALL: |
96f5fe4c JH |
3555 | log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", |
3556 | sender_fullhost ? sender_fullhost : US"<unknown>", | |
3557 | strerror(errno)); | |
3558 | return -1; | |
817d9f57 | 3559 | |
059ec3d9 | 3560 | default: |
96f5fe4c JH |
3561 | log_write(0, LOG_MAIN, "SSL_write error %d", error); |
3562 | return -1; | |
059ec3d9 PH |
3563 | } |
3564 | } | |
ac35befe | 3565 | return olen; |
059ec3d9 PH |
3566 | } |
3567 | ||
3568 | ||
3569 | ||
3570 | /************************************************* | |
3571 | * Close down a TLS session * | |
3572 | *************************************************/ | |
3573 | ||
3574 | /* This is also called from within a delivery subprocess forked from the | |
3575 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
3576 | would tamper with the SSL session in the parent process). | |
3577 | ||
dec766a1 | 3578 | Arguments: |
74f1a423 | 3579 | ct_ctx client TLS context pointer, or NULL for the one global server context |
dec766a1 WB |
3580 | shutdown 1 if TLS close-alert is to be sent, |
3581 | 2 if also response to be waited for | |
3582 | ||
059ec3d9 | 3583 | Returns: nothing |
817d9f57 JH |
3584 | |
3585 | Used by both server-side and client-side TLS. | |
059ec3d9 PH |
3586 | */ |
3587 | ||
3588 | void | |
74f1a423 | 3589 | tls_close(void * ct_ctx, int shutdown) |
059ec3d9 | 3590 | { |
74f1a423 JH |
3591 | exim_openssl_client_tls_ctx * o_ctx = ct_ctx; |
3592 | SSL_CTX **ctxp = o_ctx ? &o_ctx->ctx : &server_ctx; | |
3593 | SSL **sslp = o_ctx ? &o_ctx->ssl : &server_ssl; | |
3594 | int *fdp = o_ctx ? &tls_out.active.sock : &tls_in.active.sock; | |
817d9f57 JH |
3595 | |
3596 | if (*fdp < 0) return; /* TLS was not active */ | |
059ec3d9 PH |
3597 | |
3598 | if (shutdown) | |
3599 | { | |
dec766a1 WB |
3600 | int rc; |
3601 | DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n", | |
3602 | shutdown > 1 ? " (with response-wait)" : ""); | |
3603 | ||
3604 | if ( (rc = SSL_shutdown(*sslp)) == 0 /* send "close notify" alert */ | |
3605 | && shutdown > 1) | |
3606 | { | |
c2a1bba0 | 3607 | ALARM(2); |
dec766a1 | 3608 | rc = SSL_shutdown(*sslp); /* wait for response */ |
c2a1bba0 | 3609 | ALARM_CLR(0); |
dec766a1 WB |
3610 | } |
3611 | ||
3612 | if (rc < 0) DEBUG(D_tls) | |
3613 | { | |
0abc5a13 | 3614 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
dec766a1 WB |
3615 | debug_printf("SSL_shutdown: %s\n", ssl_errstring); |
3616 | } | |
3617 | } | |
3618 | ||
74f1a423 | 3619 | if (!o_ctx) /* server side */ |
dec766a1 | 3620 | { |
bd231acd | 3621 | #ifndef DISABLE_OCSP |
dec766a1 | 3622 | sk_X509_pop_free(server_static_cbinfo->verify_stack, X509_free); |
dec766a1 | 3623 | server_static_cbinfo->verify_stack = NULL; |
37f0ce65 | 3624 | #endif |
059ec3d9 | 3625 | |
bd231acd JH |
3626 | receive_getc = smtp_getc; |
3627 | receive_getbuf = smtp_getbuf; | |
3628 | receive_get_cache = smtp_get_cache; | |
3629 | receive_ungetc = smtp_ungetc; | |
3630 | receive_feof = smtp_feof; | |
3631 | receive_ferror = smtp_ferror; | |
3632 | receive_smtp_buffered = smtp_buffered; | |
3633 | tls_in.active.tls_ctx = NULL; | |
3634 | tls_in.sni = NULL; | |
3635 | /* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */ | |
3636 | } | |
3637 | ||
dec766a1 | 3638 | SSL_CTX_free(*ctxp); |
817d9f57 | 3639 | SSL_free(*sslp); |
dec766a1 | 3640 | *ctxp = NULL; |
817d9f57 | 3641 | *sslp = NULL; |
817d9f57 | 3642 | *fdp = -1; |
059ec3d9 PH |
3643 | } |
3644 | ||
36f12725 NM |
3645 | |
3646 | ||
3647 | ||
3375e053 PP |
3648 | /************************************************* |
3649 | * Let tls_require_ciphers be checked at startup * | |
3650 | *************************************************/ | |
3651 | ||
3652 | /* The tls_require_ciphers option, if set, must be something which the | |
3653 | library can parse. | |
3654 | ||
3655 | Returns: NULL on success, or error message | |
3656 | */ | |
3657 | ||
3658 | uschar * | |
3659 | tls_validate_require_cipher(void) | |
3660 | { | |
3661 | SSL_CTX *ctx; | |
3662 | uschar *s, *expciphers, *err; | |
3663 | ||
3664 | /* this duplicates from tls_init(), we need a better "init just global | |
3665 | state, for no specific purpose" singleton function of our own */ | |
3666 | ||
7434882d | 3667 | #ifdef EXIM_NEED_OPENSSL_INIT |
3375e053 PP |
3668 | SSL_load_error_strings(); |
3669 | OpenSSL_add_ssl_algorithms(); | |
7434882d | 3670 | #endif |
3375e053 PP |
3671 | #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) |
3672 | /* SHA256 is becoming ever more popular. This makes sure it gets added to the | |
3673 | list of available digests. */ | |
3674 | EVP_add_digest(EVP_sha256()); | |
3675 | #endif | |
3676 | ||
3677 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
3678 | return NULL; | |
3679 | ||
cf0c6164 JH |
3680 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers, |
3681 | &err)) | |
3375e053 PP |
3682 | return US"failed to expand tls_require_ciphers"; |
3683 | ||
3684 | if (!(expciphers && *expciphers)) | |
3685 | return NULL; | |
3686 | ||
3687 | /* normalisation ripped from above */ | |
3688 | s = expciphers; | |
3689 | while (*s != 0) { if (*s == '_') *s = '-'; s++; } | |
3690 | ||
3691 | err = NULL; | |
3692 | ||
7a8b9519 JH |
3693 | #ifdef EXIM_HAVE_OPENSSL_TLS_METHOD |
3694 | if (!(ctx = SSL_CTX_new(TLS_server_method()))) | |
3695 | #else | |
3696 | if (!(ctx = SSL_CTX_new(SSLv23_server_method()))) | |
3697 | #endif | |
3375e053 | 3698 | { |
0abc5a13 | 3699 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
3375e053 PP |
3700 | return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring); |
3701 | } | |
3702 | ||
3703 | DEBUG(D_tls) | |
3704 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
3705 | ||
3706 | if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) | |
3707 | { | |
0abc5a13 | 3708 | ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring)); |
cf0c6164 JH |
3709 | err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed: %s", |
3710 | expciphers, ssl_errstring); | |
3375e053 PP |
3711 | } |
3712 | ||
3713 | SSL_CTX_free(ctx); | |
3714 | ||
3715 | return err; | |
3716 | } | |
3717 | ||
3718 | ||
3719 | ||
3720 | ||
36f12725 NM |
3721 | /************************************************* |
3722 | * Report the library versions. * | |
3723 | *************************************************/ | |
3724 | ||
3725 | /* There have historically been some issues with binary compatibility in | |
3726 | OpenSSL libraries; if Exim (like many other applications) is built against | |
3727 | one version of OpenSSL but the run-time linker picks up another version, | |
3728 | it can result in serious failures, including crashing with a SIGSEGV. So | |
3729 | report the version found by the compiler and the run-time version. | |
3730 | ||
f64a1e23 PP |
3731 | Note: some OS vendors backport security fixes without changing the version |
3732 | number/string, and the version date remains unchanged. The _build_ date | |
3733 | will change, so we can more usefully assist with version diagnosis by also | |
3734 | reporting the build date. | |
3735 | ||
36f12725 NM |
3736 | Arguments: a FILE* to print the results to |
3737 | Returns: nothing | |
3738 | */ | |
3739 | ||
3740 | void | |
3741 | tls_version_report(FILE *f) | |
3742 | { | |
754a0503 | 3743 | fprintf(f, "Library version: OpenSSL: Compile: %s\n" |
f64a1e23 PP |
3744 | " Runtime: %s\n" |
3745 | " : %s\n", | |
754a0503 | 3746 | OPENSSL_VERSION_TEXT, |
f64a1e23 PP |
3747 | SSLeay_version(SSLEAY_VERSION), |
3748 | SSLeay_version(SSLEAY_BUILT_ON)); | |
3749 | /* third line is 38 characters for the %s and the line is 73 chars long; | |
3750 | the OpenSSL output includes a "built on: " prefix already. */ | |
36f12725 NM |
3751 | } |
3752 | ||
9e3331ea TK |
3753 | |
3754 | ||
3755 | ||
3756 | /************************************************* | |
17c76198 | 3757 | * Random number generation * |
9e3331ea TK |
3758 | *************************************************/ |
3759 | ||
3760 | /* Pseudo-random number generation. The result is not expected to be | |
3761 | cryptographically strong but not so weak that someone will shoot themselves | |
3762 | in the foot using it as a nonce in input in some email header scheme or | |
3763 | whatever weirdness they'll twist this into. The result should handle fork() | |
3764 | and avoid repeating sequences. OpenSSL handles that for us. | |
3765 | ||
3766 | Arguments: | |
3767 | max range maximum | |
3768 | Returns a random number in range [0, max-1] | |
3769 | */ | |
3770 | ||
3771 | int | |
17c76198 | 3772 | vaguely_random_number(int max) |
9e3331ea TK |
3773 | { |
3774 | unsigned int r; | |
3775 | int i, needed_len; | |
de6135a0 PP |
3776 | static pid_t pidlast = 0; |
3777 | pid_t pidnow; | |
9e3331ea TK |
3778 | uschar smallbuf[sizeof(r)]; |
3779 | ||
3780 | if (max <= 1) | |
3781 | return 0; | |
3782 | ||
de6135a0 PP |
3783 | pidnow = getpid(); |
3784 | if (pidnow != pidlast) | |
3785 | { | |
3786 | /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state | |
3787 | is unique for each thread", this doesn't apparently apply across processes, | |
3788 | so our own warning from vaguely_random_number_fallback() applies here too. | |
3789 | Fix per PostgreSQL. */ | |
3790 | if (pidlast != 0) | |
3791 | RAND_cleanup(); | |
3792 | pidlast = pidnow; | |
3793 | } | |
3794 | ||
9e3331ea TK |
3795 | /* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ |
3796 | if (!RAND_status()) | |
3797 | { | |
3798 | randstuff r; | |
3799 | gettimeofday(&r.tv, NULL); | |
3800 | r.p = getpid(); | |
3801 | ||
5903c6ff | 3802 | RAND_seed(US (&r), sizeof(r)); |
9e3331ea TK |
3803 | } |
3804 | /* We're after pseudo-random, not random; if we still don't have enough data | |
3805 | in the internal PRNG then our options are limited. We could sleep and hope | |
3806 | for entropy to come along (prayer technique) but if the system is so depleted | |
3807 | in the first place then something is likely to just keep taking it. Instead, | |
3808 | we'll just take whatever little bit of pseudo-random we can still manage to | |
3809 | get. */ | |
3810 | ||
3811 | needed_len = sizeof(r); | |
3812 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
3813 | asked for a number less than 10. */ | |
3814 | for (r = max, i = 0; r; ++i) | |
3815 | r >>= 1; | |
3816 | i = (i + 7) / 8; | |
3817 | if (i < needed_len) | |
3818 | needed_len = i; | |
3819 | ||
c8dfb21d | 3820 | #ifdef EXIM_HAVE_RAND_PSEUDO |
9e3331ea | 3821 | /* We do not care if crypto-strong */ |
17c76198 | 3822 | i = RAND_pseudo_bytes(smallbuf, needed_len); |
c8dfb21d JH |
3823 | #else |
3824 | i = RAND_bytes(smallbuf, needed_len); | |
3825 | #endif | |
3826 | ||
17c76198 PP |
3827 | if (i < 0) |
3828 | { | |
3829 | DEBUG(D_all) | |
3830 | debug_printf("OpenSSL RAND_pseudo_bytes() not supported by RAND method, using fallback.\n"); | |
3831 | return vaguely_random_number_fallback(max); | |
3832 | } | |
3833 | ||
9e3331ea | 3834 | r = 0; |
d7978c0f JH |
3835 | for (uschar * p = smallbuf; needed_len; --needed_len, ++p) |
3836 | r = 256 * r + *p; | |
9e3331ea TK |
3837 | |
3838 | /* We don't particularly care about weighted results; if someone wants | |
3839 | smooth distribution and cares enough then they should submit a patch then. */ | |
3840 | return r % max; | |
3841 | } | |
3842 | ||
77bb000f PP |
3843 | |
3844 | ||
3845 | ||
3846 | /************************************************* | |
3847 | * OpenSSL option parse * | |
3848 | *************************************************/ | |
3849 | ||
3850 | /* Parse one option for tls_openssl_options_parse below | |
3851 | ||
3852 | Arguments: | |
3853 | name one option name | |
3854 | value place to store a value for it | |
3855 | Returns success or failure in parsing | |
3856 | */ | |
3857 | ||
77bb000f | 3858 | |
c80c5570 | 3859 | |
77bb000f PP |
3860 | static BOOL |
3861 | tls_openssl_one_option_parse(uschar *name, long *value) | |
3862 | { | |
3863 | int first = 0; | |
3864 | int last = exim_openssl_options_size; | |
3865 | while (last > first) | |
3866 | { | |
3867 | int middle = (first + last)/2; | |
3868 | int c = Ustrcmp(name, exim_openssl_options[middle].name); | |
3869 | if (c == 0) | |
3870 | { | |
3871 | *value = exim_openssl_options[middle].value; | |
3872 | return TRUE; | |
3873 | } | |
3874 | else if (c > 0) | |
3875 | first = middle + 1; | |
3876 | else | |
3877 | last = middle; | |
3878 | } | |
3879 | return FALSE; | |
3880 | } | |
3881 | ||
3882 | ||
3883 | ||
3884 | ||
3885 | /************************************************* | |
3886 | * OpenSSL option parsing logic * | |
3887 | *************************************************/ | |
3888 | ||
3889 | /* OpenSSL has a number of compatibility options which an administrator might | |
3890 | reasonably wish to set. Interpret a list similarly to decode_bits(), so that | |
3891 | we look like log_selector. | |
3892 | ||
3893 | Arguments: | |
3894 | option_spec the administrator-supplied string of options | |
3895 | results ptr to long storage for the options bitmap | |
3896 | Returns success or failure | |
3897 | */ | |
3898 | ||
3899 | BOOL | |
3900 | tls_openssl_options_parse(uschar *option_spec, long *results) | |
3901 | { | |
3902 | long result, item; | |
d7978c0f | 3903 | uschar *end; |
77bb000f PP |
3904 | uschar keep_c; |
3905 | BOOL adding, item_parsed; | |
3906 | ||
b10c87b3 | 3907 | /* Server: send no (<= TLS1.2) session tickets */ |
7006ee24 | 3908 | result = SSL_OP_NO_TICKET; |
b10c87b3 | 3909 | |
b1770b6e | 3910 | /* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed |
da3ad30d | 3911 | * from default because it increases BEAST susceptibility. */ |
f0f5a555 PP |
3912 | #ifdef SSL_OP_NO_SSLv2 |
3913 | result |= SSL_OP_NO_SSLv2; | |
3914 | #endif | |
b10c87b3 JH |
3915 | #ifdef SSL_OP_NO_SSLv3 |
3916 | result |= SSL_OP_NO_SSLv3; | |
3917 | #endif | |
a57b6200 JH |
3918 | #ifdef SSL_OP_SINGLE_DH_USE |
3919 | result |= SSL_OP_SINGLE_DH_USE; | |
3920 | #endif | |
77bb000f | 3921 | |
7006ee24 | 3922 | if (!option_spec) |
77bb000f PP |
3923 | { |
3924 | *results = result; | |
3925 | return TRUE; | |
3926 | } | |
3927 | ||
b10c87b3 | 3928 | for (uschar * s = option_spec; *s; /**/) |
77bb000f PP |
3929 | { |
3930 | while (isspace(*s)) ++s; | |
3931 | if (*s == '\0') | |
3932 | break; | |
3933 | if (*s != '+' && *s != '-') | |
3934 | { | |
3935 | DEBUG(D_tls) debug_printf("malformed openssl option setting: " | |
0e944a0d | 3936 | "+ or - expected but found \"%s\"\n", s); |
77bb000f PP |
3937 | return FALSE; |
3938 | } | |
3939 | adding = *s++ == '+'; | |
3940 | for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; | |
3941 | keep_c = *end; | |
3942 | *end = '\0'; | |
3943 | item_parsed = tls_openssl_one_option_parse(s, &item); | |
96f5fe4c | 3944 | *end = keep_c; |
77bb000f PP |
3945 | if (!item_parsed) |
3946 | { | |
0e944a0d | 3947 | DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); |
77bb000f PP |
3948 | return FALSE; |
3949 | } | |
f97ca6d1 JH |
3950 | DEBUG(D_tls) debug_printf("openssl option, %s %8lx: %lx (%s)\n", |
3951 | adding ? "adding to " : "removing from", result, item, s); | |
77bb000f PP |
3952 | if (adding) |
3953 | result |= item; | |
3954 | else | |
3955 | result &= ~item; | |
77bb000f PP |
3956 | s = end; |
3957 | } | |
3958 | ||
3959 | *results = result; | |
3960 | return TRUE; | |
3961 | } | |
3962 | ||
8442641e | 3963 | #endif /*!MACRO_PREDEF*/ |
9d1c15ef JH |
3964 | /* vi: aw ai sw=2 |
3965 | */ | |
059ec3d9 | 3966 | /* End of tls-openssl.c */ |