Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
3386088d | 5 | /* Copyright (c) University of Cambridge 1995 - 2015 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
17c76198 | 8 | /* Copyright (c) Phil Pennock 2012 */ |
059ec3d9 | 9 | |
17c76198 PP |
10 | /* This file provides TLS/SSL support for Exim using the GnuTLS library, |
11 | one of the available supported implementations. This file is #included into | |
12 | tls.c when USE_GNUTLS has been set. | |
059ec3d9 | 13 | |
17c76198 PP |
14 | The code herein is a revamp of GnuTLS integration using the current APIs; the |
15 | original tls-gnu.c was based on a patch which was contributed by Nikos | |
16 | Mavroyanopoulos. The revamp is partially a rewrite, partially cut&paste as | |
17 | appropriate. | |
059ec3d9 | 18 | |
17c76198 PP |
19 | APIs current as of GnuTLS 2.12.18; note that the GnuTLS manual is for GnuTLS 3, |
20 | which is not widely deployed by OS vendors. Will note issues below, which may | |
21 | assist in updating the code in the future. Another sources of hints is | |
22 | mod_gnutls for Apache (SNI callback registration and handling). | |
059ec3d9 | 23 | |
17c76198 PP |
24 | Keeping client and server variables more split than before and is currently |
25 | the norm, in anticipation of TLS in ACL callouts. | |
059ec3d9 | 26 | |
17c76198 PP |
27 | I wanted to switch to gnutls_certificate_set_verify_function() so that |
28 | certificate rejection could happen during handshake where it belongs, rather | |
29 | than being dropped afterwards, but that was introduced in 2.10.0 and Debian | |
30 | (6.0.5) is still on 2.8.6. So for now we have to stick with sub-par behaviour. | |
059ec3d9 | 31 | |
17c76198 PP |
32 | (I wasn't looking for libraries quite that old, when updating to get rid of |
33 | compiler warnings of deprecated APIs. If it turns out that a lot of the rest | |
34 | require current GnuTLS, then we'll drop support for the ancient libraries). | |
35 | */ | |
b5aea5e1 | 36 | |
17c76198 PP |
37 | #include <gnutls/gnutls.h> |
38 | /* needed for cert checks in verification and DN extraction: */ | |
39 | #include <gnutls/x509.h> | |
40 | /* man-page is incorrect, gnutls_rnd() is not in gnutls.h: */ | |
41 | #include <gnutls/crypto.h> | |
a5f239e4 PP |
42 | /* needed to disable PKCS11 autoload unless requested */ |
43 | #if GNUTLS_VERSION_NUMBER >= 0x020c00 | |
44 | # include <gnutls/pkcs11.h> | |
45 | #endif | |
7e07527a JH |
46 | #if GNUTLS_VERSION_NUMBER < 0x030103 && !defined(DISABLE_OCSP) |
47 | # warning "GnuTLS library version too old; define DISABLE_OCSP in Makefile" | |
48 | # define DISABLE_OCSP | |
49 | #endif | |
0cbf2b82 | 50 | #if GNUTLS_VERSION_NUMBER < 0x020a00 && !defined(DISABLE_EVENT) |
774ef2d7 | 51 | # warning "GnuTLS library version too old; tls:cert event unsupported" |
0cbf2b82 | 52 | # define DISABLE_EVENT |
a7538db1 | 53 | #endif |
a7fec7a7 JH |
54 | #if GNUTLS_VERSION_NUMBER >= 0x030306 |
55 | # define SUPPORT_CA_DIR | |
56 | #else | |
57 | # undef SUPPORT_CA_DIR | |
58 | #endif | |
11a04b5a | 59 | #if GNUTLS_VERSION_NUMBER >= 0x030014 |
cb1d7830 JH |
60 | # define SUPPORT_SYSDEFAULT_CABUNDLE |
61 | #endif | |
7e07527a | 62 | |
f2de3a33 | 63 | #ifndef DISABLE_OCSP |
2b4a568d JH |
64 | # include <gnutls/ocsp.h> |
65 | #endif | |
059ec3d9 | 66 | |
17c76198 | 67 | /* GnuTLS 2 vs 3 |
059ec3d9 | 68 | |
17c76198 PP |
69 | GnuTLS 3 only: |
70 | gnutls_global_set_audit_log_function() | |
059ec3d9 | 71 | |
17c76198 PP |
72 | Changes: |
73 | gnutls_certificate_verify_peers2(): is new, drop the 2 for old version | |
74 | */ | |
059ec3d9 | 75 | |
17c76198 | 76 | /* Local static variables for GnuTLS */ |
059ec3d9 | 77 | |
17c76198 | 78 | /* Values for verify_requirement */ |
059ec3d9 | 79 | |
e51c7be2 | 80 | enum peer_verify_requirement |
aa2a70ba | 81 | { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED }; |
059ec3d9 | 82 | |
17c76198 PP |
83 | /* This holds most state for server or client; with this, we can set up an |
84 | outbound TLS-enabled connection in an ACL callout, while not stomping all | |
85 | over the TLS variables available for expansion. | |
059ec3d9 | 86 | |
17c76198 PP |
87 | Some of these correspond to variables in globals.c; those variables will |
88 | be set to point to content in one of these instances, as appropriate for | |
89 | the stage of the process lifetime. | |
059ec3d9 | 90 | |
389ca47a | 91 | Not handled here: global tls_channelbinding_b64. |
17c76198 | 92 | */ |
059ec3d9 | 93 | |
17c76198 | 94 | typedef struct exim_gnutls_state { |
9d1c15ef | 95 | gnutls_session_t session; |
17c76198 | 96 | gnutls_certificate_credentials_t x509_cred; |
9d1c15ef | 97 | gnutls_priority_t priority_cache; |
17c76198 | 98 | enum peer_verify_requirement verify_requirement; |
9d1c15ef JH |
99 | int fd_in; |
100 | int fd_out; | |
101 | BOOL peer_cert_verified; | |
102 | BOOL trigger_sni_changes; | |
103 | BOOL have_set_peerdn; | |
17c76198 | 104 | const struct host_item *host; |
9d1c15ef JH |
105 | gnutls_x509_crt_t peercert; |
106 | uschar *peerdn; | |
107 | uschar *ciphersuite; | |
108 | uschar *received_sni; | |
17c76198 PP |
109 | |
110 | const uschar *tls_certificate; | |
111 | const uschar *tls_privatekey; | |
112 | const uschar *tls_sni; /* client send only, not received */ | |
113 | const uschar *tls_verify_certificates; | |
114 | const uschar *tls_crl; | |
115 | const uschar *tls_require_ciphers; | |
e51c7be2 | 116 | |
17c76198 PP |
117 | uschar *exp_tls_certificate; |
118 | uschar *exp_tls_privatekey; | |
17c76198 PP |
119 | uschar *exp_tls_verify_certificates; |
120 | uschar *exp_tls_crl; | |
121 | uschar *exp_tls_require_ciphers; | |
44662487 | 122 | uschar *exp_tls_ocsp_file; |
55414b25 | 123 | const uschar *exp_tls_verify_cert_hostnames; |
0cbf2b82 | 124 | #ifndef DISABLE_EVENT |
a7538db1 JH |
125 | uschar *event_action; |
126 | #endif | |
17c76198 | 127 | |
389ca47a | 128 | tls_support *tlsp; /* set in tls_init() */ |
817d9f57 | 129 | |
17c76198 PP |
130 | uschar *xfer_buffer; |
131 | int xfer_buffer_lwm; | |
132 | int xfer_buffer_hwm; | |
133 | int xfer_eof; | |
134 | int xfer_error; | |
17c76198 PP |
135 | } exim_gnutls_state_st; |
136 | ||
137 | static const exim_gnutls_state_st exim_gnutls_state_init = { | |
4fe99a6c | 138 | NULL, NULL, NULL, VERIFY_NONE, -1, -1, FALSE, FALSE, FALSE, |
75fe387d | 139 | NULL, NULL, NULL, NULL, |
17c76198 | 140 | NULL, NULL, NULL, NULL, NULL, NULL, |
44662487 | 141 | NULL, NULL, NULL, NULL, NULL, NULL, NULL, |
01a4a5c5 | 142 | NULL, |
0cbf2b82 | 143 | #ifndef DISABLE_EVENT |
a7538db1 | 144 | NULL, |
e51c7be2 | 145 | #endif |
817d9f57 | 146 | NULL, |
17c76198 | 147 | NULL, 0, 0, 0, 0, |
17c76198 | 148 | }; |
83da1223 | 149 | |
17c76198 PP |
150 | /* Not only do we have our own APIs which don't pass around state, assuming |
151 | it's held in globals, GnuTLS doesn't appear to let us register callback data | |
152 | for callbacks, or as part of the session, so we have to keep a "this is the | |
153 | context we're currently dealing with" pointer and rely upon being | |
154 | single-threaded to keep from processing data on an inbound TLS connection while | |
155 | talking to another TLS connection for an outbound check. This does mean that | |
156 | there's no way for heart-beats to be responded to, for the duration of the | |
a7538db1 JH |
157 | second connection. |
158 | XXX But see gnutls_session_get_ptr() | |
159 | */ | |
059ec3d9 | 160 | |
17c76198 | 161 | static exim_gnutls_state_st state_server, state_client; |
059ec3d9 | 162 | |
17c76198 PP |
163 | /* dh_params are initialised once within the lifetime of a process using TLS; |
164 | if we used TLS in a long-lived daemon, we'd have to reconsider this. But we | |
165 | don't want to repeat this. */ | |
83da1223 | 166 | |
17c76198 | 167 | static gnutls_dh_params_t dh_server_params = NULL; |
059ec3d9 | 168 | |
17c76198 | 169 | /* No idea how this value was chosen; preserving it. Default is 3600. */ |
059ec3d9 | 170 | |
17c76198 | 171 | static const int ssl_session_timeout = 200; |
059ec3d9 | 172 | |
17c76198 | 173 | static const char * const exim_default_gnutls_priority = "NORMAL"; |
83da1223 | 174 | |
17c76198 | 175 | /* Guard library core initialisation */ |
83da1223 | 176 | |
17c76198 | 177 | static BOOL exim_gnutls_base_init_done = FALSE; |
059ec3d9 | 178 | |
4fb7df6d | 179 | #ifndef DISABLE_OCSP |
9196d5bf | 180 | static BOOL gnutls_buggy_ocsp = FALSE; |
4fb7df6d | 181 | #endif |
9196d5bf | 182 | |
059ec3d9 | 183 | |
17c76198 PP |
184 | /* ------------------------------------------------------------------------ */ |
185 | /* macros */ | |
83da1223 | 186 | |
17c76198 | 187 | #define MAX_HOST_LEN 255 |
83da1223 | 188 | |
17c76198 PP |
189 | /* Set this to control gnutls_global_set_log_level(); values 0 to 9 will setup |
190 | the library logging; a value less than 0 disables the calls to set up logging | |
191 | callbacks. */ | |
2c17bb02 | 192 | #ifndef EXIM_GNUTLS_LIBRARY_LOG_LEVEL |
a7538db1 | 193 | # define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1 |
2c17bb02 | 194 | #endif |
83da1223 | 195 | |
2c17bb02 | 196 | #ifndef EXIM_CLIENT_DH_MIN_BITS |
a7538db1 | 197 | # define EXIM_CLIENT_DH_MIN_BITS 1024 |
2c17bb02 | 198 | #endif |
83da1223 | 199 | |
af3498d6 PP |
200 | /* With GnuTLS 2.12.x+ we have gnutls_sec_param_to_pk_bits() with which we |
201 | can ask for a bit-strength. Without that, we stick to the constant we had | |
202 | before, for now. */ | |
2c17bb02 | 203 | #ifndef EXIM_SERVER_DH_BITS_PRE2_12 |
a7538db1 | 204 | # define EXIM_SERVER_DH_BITS_PRE2_12 1024 |
2c17bb02 | 205 | #endif |
af3498d6 | 206 | |
17c76198 PP |
207 | #define exim_gnutls_err_check(Label) do { \ |
208 | if (rc != GNUTLS_E_SUCCESS) { return tls_error((Label), gnutls_strerror(rc), host); } } while (0) | |
059ec3d9 | 209 | |
17c76198 | 210 | #define expand_check_tlsvar(Varname) expand_check(state->Varname, US #Varname, &state->exp_##Varname) |
83da1223 | 211 | |
17c76198 | 212 | #if GNUTLS_VERSION_NUMBER >= 0x020c00 |
e51c7be2 JH |
213 | # define HAVE_GNUTLS_SESSION_CHANNEL_BINDING |
214 | # define HAVE_GNUTLS_SEC_PARAM_CONSTANTS | |
215 | # define HAVE_GNUTLS_RND | |
2519e60d TL |
216 | /* The security fix we provide with the gnutls_allow_auto_pkcs11 option |
217 | * (4.82 PP/09) introduces a compatibility regression. The symbol simply | |
218 | * isn't available sometimes, so this needs to become a conditional | |
219 | * compilation; the sanest way to deal with this being a problem on | |
220 | * older OSes is to block it in the Local/Makefile with this compiler | |
221 | * definition */ | |
e51c7be2 JH |
222 | # ifndef AVOID_GNUTLS_PKCS11 |
223 | # define HAVE_GNUTLS_PKCS11 | |
224 | # endif /* AVOID_GNUTLS_PKCS11 */ | |
17c76198 | 225 | #endif |
83da1223 | 226 | |
af3498d6 PP |
227 | |
228 | ||
229 | ||
230 | /* ------------------------------------------------------------------------ */ | |
231 | /* Callback declarations */ | |
232 | ||
233 | #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 | |
234 | static void exim_gnutls_logger_cb(int level, const char *message); | |
235 | #endif | |
236 | ||
237 | static int exim_sni_handling_cb(gnutls_session_t session); | |
238 | ||
f2de3a33 | 239 | #ifndef DISABLE_OCSP |
44662487 JH |
240 | static int server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, |
241 | gnutls_datum_t * ocsp_response); | |
242 | #endif | |
af3498d6 PP |
243 | |
244 | ||
245 | ||
17c76198 PP |
246 | /* ------------------------------------------------------------------------ */ |
247 | /* Static functions */ | |
059ec3d9 PH |
248 | |
249 | /************************************************* | |
250 | * Handle TLS error * | |
251 | *************************************************/ | |
252 | ||
253 | /* Called from lots of places when errors occur before actually starting to do | |
254 | the TLS handshake, that is, while the session is still in clear. Always returns | |
255 | DEFER for a server and FAIL for a client so that most calls can use "return | |
256 | tls_error(...)" to do this processing and then give an appropriate return. A | |
257 | single function is used for both server and client, because it is called from | |
258 | some shared functions. | |
259 | ||
260 | Argument: | |
261 | prefix text to include in the logged error | |
7199e1ee TF |
262 | msg additional error string (may be NULL) |
263 | usually obtained from gnutls_strerror() | |
17c76198 PP |
264 | host NULL if setting up a server; |
265 | the connected host if setting up a client | |
059ec3d9 PH |
266 | |
267 | Returns: OK/DEFER/FAIL | |
268 | */ | |
269 | ||
270 | static int | |
17c76198 | 271 | tls_error(const uschar *prefix, const char *msg, const host_item *host) |
059ec3d9 | 272 | { |
17c76198 PP |
273 | if (host) |
274 | { | |
c562fd30 | 275 | log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection (%s)%s%s", |
17c76198 PP |
276 | host->name, host->address, prefix, msg ? ": " : "", msg ? msg : ""); |
277 | return FAIL; | |
278 | } | |
279 | else | |
059ec3d9 | 280 | { |
7199e1ee | 281 | uschar *conn_info = smtp_get_connection_info(); |
17c76198 | 282 | if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) |
7199e1ee | 283 | conn_info += 5; |
c562fd30 | 284 | /* I'd like to get separated H= here, but too hard for now */ |
7199e1ee | 285 | log_write(0, LOG_MAIN, "TLS error on %s (%s)%s%s", |
17c76198 | 286 | conn_info, prefix, msg ? ": " : "", msg ? msg : ""); |
059ec3d9 PH |
287 | return DEFER; |
288 | } | |
059ec3d9 PH |
289 | } |
290 | ||
291 | ||
292 | ||
17c76198 | 293 | |
059ec3d9 | 294 | /************************************************* |
17c76198 | 295 | * Deal with logging errors during I/O * |
059ec3d9 PH |
296 | *************************************************/ |
297 | ||
17c76198 | 298 | /* We have to get the identity of the peer from saved data. |
059ec3d9 | 299 | |
17c76198 PP |
300 | Argument: |
301 | state the current GnuTLS exim state container | |
302 | rc the GnuTLS error code, or 0 if it's a local error | |
303 | when text identifying read or write | |
304 | text local error text when ec is 0 | |
059ec3d9 | 305 | |
17c76198 | 306 | Returns: nothing |
059ec3d9 PH |
307 | */ |
308 | ||
17c76198 PP |
309 | static void |
310 | record_io_error(exim_gnutls_state_st *state, int rc, uschar *when, uschar *text) | |
059ec3d9 | 311 | { |
17c76198 | 312 | const char *msg; |
059ec3d9 | 313 | |
17c76198 PP |
314 | if (rc == GNUTLS_E_FATAL_ALERT_RECEIVED) |
315 | msg = CS string_sprintf("%s: %s", US gnutls_strerror(rc), | |
316 | US gnutls_alert_get_name(gnutls_alert_get(state->session))); | |
317 | else | |
318 | msg = gnutls_strerror(rc); | |
059ec3d9 | 319 | |
17c76198 PP |
320 | tls_error(when, msg, state->host); |
321 | } | |
059ec3d9 | 322 | |
059ec3d9 | 323 | |
059ec3d9 | 324 | |
059ec3d9 | 325 | |
17c76198 PP |
326 | /************************************************* |
327 | * Set various Exim expansion vars * | |
328 | *************************************************/ | |
059ec3d9 | 329 | |
e51c7be2 JH |
330 | #define exim_gnutls_cert_err(Label) \ |
331 | do \ | |
332 | { \ | |
333 | if (rc != GNUTLS_E_SUCCESS) \ | |
334 | { \ | |
335 | DEBUG(D_tls) debug_printf("TLS: cert problem: %s: %s\n", \ | |
336 | (Label), gnutls_strerror(rc)); \ | |
337 | return rc; \ | |
338 | } \ | |
339 | } while (0) | |
9d1c15ef JH |
340 | |
341 | static int | |
27f19eb4 | 342 | import_cert(const gnutls_datum_t * cert, gnutls_x509_crt_t * crtp) |
9d1c15ef JH |
343 | { |
344 | int rc; | |
345 | ||
346 | rc = gnutls_x509_crt_init(crtp); | |
347 | exim_gnutls_cert_err(US"gnutls_x509_crt_init (crt)"); | |
348 | ||
349 | rc = gnutls_x509_crt_import(*crtp, cert, GNUTLS_X509_FMT_DER); | |
350 | exim_gnutls_cert_err(US"failed to import certificate [gnutls_x509_crt_import(cert)]"); | |
351 | ||
352 | return rc; | |
353 | } | |
354 | ||
355 | #undef exim_gnutls_cert_err | |
356 | ||
357 | ||
17c76198 PP |
358 | /* We set various Exim global variables from the state, once a session has |
359 | been established. With TLS callouts, may need to change this to stack | |
360 | variables, or just re-call it with the server state after client callout | |
361 | has finished. | |
059ec3d9 | 362 | |
9d1c15ef | 363 | Make sure anything set here is unset in tls_getc(). |
17c76198 PP |
364 | |
365 | Sets: | |
366 | tls_active fd | |
367 | tls_bits strength indicator | |
368 | tls_certificate_verified bool indicator | |
369 | tls_channelbinding_b64 for some SASL mechanisms | |
370 | tls_cipher a string | |
9d1c15ef | 371 | tls_peercert pointer to library internal |
17c76198 PP |
372 | tls_peerdn a string |
373 | tls_sni a (UTF-8) string | |
9d1c15ef | 374 | tls_ourcert pointer to library internal |
17c76198 PP |
375 | |
376 | Argument: | |
377 | state the relevant exim_gnutls_state_st * | |
378 | */ | |
379 | ||
380 | static void | |
9d1c15ef | 381 | extract_exim_vars_from_tls_state(exim_gnutls_state_st * state) |
17c76198 | 382 | { |
17c76198 | 383 | gnutls_cipher_algorithm_t cipher; |
17c76198 PP |
384 | #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING |
385 | int old_pool; | |
386 | int rc; | |
387 | gnutls_datum_t channel; | |
388 | #endif | |
9d1c15ef | 389 | tls_support * tlsp = state->tlsp; |
17c76198 | 390 | |
9d1c15ef | 391 | tlsp->active = state->fd_out; |
17c76198 PP |
392 | |
393 | cipher = gnutls_cipher_get(state->session); | |
394 | /* returns size in "bytes" */ | |
9d1c15ef | 395 | tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; |
17c76198 | 396 | |
9d1c15ef | 397 | tlsp->cipher = state->ciphersuite; |
17c76198 | 398 | |
817d9f57 | 399 | DEBUG(D_tls) debug_printf("cipher: %s\n", state->ciphersuite); |
17c76198 | 400 | |
9d1c15ef | 401 | tlsp->certificate_verified = state->peer_cert_verified; |
059ec3d9 | 402 | |
17c76198 PP |
403 | /* note that tls_channelbinding_b64 is not saved to the spool file, since it's |
404 | only available for use for authenticators while this TLS session is running. */ | |
405 | ||
406 | tls_channelbinding_b64 = NULL; | |
407 | #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING | |
408 | channel.data = NULL; | |
409 | channel.size = 0; | |
410 | rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel); | |
411 | if (rc) { | |
412 | DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc)); | |
413 | } else { | |
414 | old_pool = store_pool; | |
415 | store_pool = POOL_PERM; | |
f4d091fb | 416 | tls_channelbinding_b64 = b64encode(channel.data, (int)channel.size); |
17c76198 PP |
417 | store_pool = old_pool; |
418 | DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage.\n"); | |
419 | } | |
420 | #endif | |
421 | ||
9d1c15ef JH |
422 | /* peercert is set in peer_status() */ |
423 | tlsp->peerdn = state->peerdn; | |
424 | tlsp->sni = state->received_sni; | |
425 | ||
426 | /* record our certificate */ | |
427 | { | |
27f19eb4 | 428 | const gnutls_datum_t * cert = gnutls_certificate_get_ours(state->session); |
9d1c15ef JH |
429 | gnutls_x509_crt_t crt; |
430 | ||
431 | tlsp->ourcert = cert && import_cert(cert, &crt)==0 ? crt : NULL; | |
432 | } | |
059ec3d9 PH |
433 | } |
434 | ||
435 | ||
436 | ||
17c76198 | 437 | |
059ec3d9 | 438 | /************************************************* |
575643cd | 439 | * Setup up DH parameters * |
059ec3d9 PH |
440 | *************************************************/ |
441 | ||
575643cd | 442 | /* Generating the D-H parameters may take a long time. They only need to |
059ec3d9 PH |
443 | be re-generated every so often, depending on security policy. What we do is to |
444 | keep these parameters in a file in the spool directory. If the file does not | |
445 | exist, we generate them. This means that it is easy to cause a regeneration. | |
446 | ||
447 | The new file is written as a temporary file and renamed, so that an incomplete | |
448 | file is never present. If two processes both compute some new parameters, you | |
449 | waste a bit of effort, but it doesn't seem worth messing around with locking to | |
450 | prevent this. | |
451 | ||
059ec3d9 PH |
452 | Returns: OK/DEFER/FAIL |
453 | */ | |
454 | ||
455 | static int | |
17c76198 | 456 | init_server_dh(void) |
059ec3d9 | 457 | { |
17c76198 PP |
458 | int fd, rc; |
459 | unsigned int dh_bits; | |
27f19eb4 | 460 | gnutls_datum_t m; |
a799883d PP |
461 | uschar filename_buf[PATH_MAX]; |
462 | uschar *filename = NULL; | |
17c76198 | 463 | size_t sz; |
a799883d PP |
464 | uschar *exp_tls_dhparam; |
465 | BOOL use_file_in_spool = FALSE; | |
466 | BOOL use_fixed_file = FALSE; | |
17c76198 | 467 | host_item *host = NULL; /* dummy for macros */ |
059ec3d9 | 468 | |
17c76198 | 469 | DEBUG(D_tls) debug_printf("Initialising GnuTLS server params.\n"); |
059ec3d9 | 470 | |
17c76198 PP |
471 | rc = gnutls_dh_params_init(&dh_server_params); |
472 | exim_gnutls_err_check(US"gnutls_dh_params_init"); | |
059ec3d9 | 473 | |
a799883d PP |
474 | m.data = NULL; |
475 | m.size = 0; | |
476 | ||
477 | if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam)) | |
478 | return DEFER; | |
479 | ||
480 | if (!exp_tls_dhparam) | |
481 | { | |
482 | DEBUG(D_tls) debug_printf("Loading default hard-coded DH params\n"); | |
483 | m.data = US std_dh_prime_default(); | |
484 | m.size = Ustrlen(m.data); | |
485 | } | |
486 | else if (Ustrcmp(exp_tls_dhparam, "historic") == 0) | |
487 | use_file_in_spool = TRUE; | |
488 | else if (Ustrcmp(exp_tls_dhparam, "none") == 0) | |
489 | { | |
490 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); | |
491 | return OK; | |
492 | } | |
493 | else if (exp_tls_dhparam[0] != '/') | |
494 | { | |
495 | m.data = US std_dh_prime_named(exp_tls_dhparam); | |
496 | if (m.data == NULL) | |
497 | return tls_error(US"No standard prime named", CS exp_tls_dhparam, NULL); | |
498 | m.size = Ustrlen(m.data); | |
499 | } | |
500 | else | |
501 | { | |
502 | use_fixed_file = TRUE; | |
503 | filename = exp_tls_dhparam; | |
504 | } | |
505 | ||
506 | if (m.data) | |
507 | { | |
508 | rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM); | |
509 | exim_gnutls_err_check(US"gnutls_dh_params_import_pkcs3"); | |
510 | DEBUG(D_tls) debug_printf("Loaded fixed standard D-H parameters\n"); | |
511 | return OK; | |
512 | } | |
513 | ||
af3498d6 PP |
514 | #ifdef HAVE_GNUTLS_SEC_PARAM_CONSTANTS |
515 | /* If you change this constant, also change dh_param_fn_ext so that we can use a | |
17c76198 PP |
516 | different filename and ensure we have sufficient bits. */ |
517 | dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL); | |
518 | if (!dh_bits) | |
519 | return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL); | |
af3498d6 | 520 | DEBUG(D_tls) |
b34fc30c | 521 | debug_printf("GnuTLS tells us that for D-H PK, NORMAL is %d bits.\n", |
af3498d6 PP |
522 | dh_bits); |
523 | #else | |
524 | dh_bits = EXIM_SERVER_DH_BITS_PRE2_12; | |
525 | DEBUG(D_tls) | |
526 | debug_printf("GnuTLS lacks gnutls_sec_param_to_pk_bits(), using %d bits.\n", | |
527 | dh_bits); | |
528 | #endif | |
059ec3d9 | 529 | |
3375e053 PP |
530 | /* Some clients have hard-coded limits. */ |
531 | if (dh_bits > tls_dh_max_bits) | |
532 | { | |
533 | DEBUG(D_tls) | |
534 | debug_printf("tls_dh_max_bits clamping override, using %d bits instead.\n", | |
535 | tls_dh_max_bits); | |
536 | dh_bits = tls_dh_max_bits; | |
537 | } | |
538 | ||
a799883d PP |
539 | if (use_file_in_spool) |
540 | { | |
541 | if (!string_format(filename_buf, sizeof(filename_buf), | |
542 | "%s/gnutls-params-%d", spool_directory, dh_bits)) | |
543 | return tls_error(US"overlong filename", NULL, NULL); | |
544 | filename = filename_buf; | |
545 | } | |
059ec3d9 | 546 | |
b5aea5e1 | 547 | /* Open the cache file for reading and if successful, read it and set up the |
575643cd | 548 | parameters. */ |
059ec3d9 PH |
549 | |
550 | fd = Uopen(filename, O_RDONLY, 0); | |
b5aea5e1 | 551 | if (fd >= 0) |
059ec3d9 | 552 | { |
b5aea5e1 | 553 | struct stat statbuf; |
17c76198 PP |
554 | FILE *fp; |
555 | int saved_errno; | |
556 | ||
557 | if (fstat(fd, &statbuf) < 0) /* EIO */ | |
558 | { | |
559 | saved_errno = errno; | |
560 | (void)close(fd); | |
561 | return tls_error(US"TLS cache stat failed", strerror(saved_errno), NULL); | |
562 | } | |
563 | if (!S_ISREG(statbuf.st_mode)) | |
b5aea5e1 PH |
564 | { |
565 | (void)close(fd); | |
17c76198 PP |
566 | return tls_error(US"TLS cache not a file", NULL, NULL); |
567 | } | |
568 | fp = fdopen(fd, "rb"); | |
569 | if (!fp) | |
570 | { | |
571 | saved_errno = errno; | |
572 | (void)close(fd); | |
573 | return tls_error(US"fdopen(TLS cache stat fd) failed", | |
574 | strerror(saved_errno), NULL); | |
b5aea5e1 | 575 | } |
059ec3d9 | 576 | |
b5aea5e1 PH |
577 | m.size = statbuf.st_size; |
578 | m.data = malloc(m.size); | |
579 | if (m.data == NULL) | |
17c76198 PP |
580 | { |
581 | fclose(fp); | |
582 | return tls_error(US"malloc failed", strerror(errno), NULL); | |
583 | } | |
584 | sz = fread(m.data, m.size, 1, fp); | |
585 | if (!sz) | |
586 | { | |
587 | saved_errno = errno; | |
588 | fclose(fp); | |
589 | free(m.data); | |
590 | return tls_error(US"fread failed", strerror(saved_errno), NULL); | |
591 | } | |
592 | fclose(fp); | |
b5aea5e1 | 593 | |
17c76198 | 594 | rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM); |
b5aea5e1 | 595 | free(m.data); |
17c76198 PP |
596 | exim_gnutls_err_check(US"gnutls_dh_params_import_pkcs3"); |
597 | DEBUG(D_tls) debug_printf("read D-H parameters from file \"%s\"\n", filename); | |
b5aea5e1 PH |
598 | } |
599 | ||
600 | /* If the file does not exist, fall through to compute new data and cache it. | |
601 | If there was any other opening error, it is serious. */ | |
602 | ||
182ad5cf PH |
603 | else if (errno == ENOENT) |
604 | { | |
17c76198 | 605 | rc = -1; |
182ad5cf | 606 | DEBUG(D_tls) |
17c76198 | 607 | debug_printf("D-H parameter cache file \"%s\" does not exist\n", filename); |
182ad5cf PH |
608 | } |
609 | else | |
17c76198 PP |
610 | return tls_error(string_open_failed(errno, "\"%s\" for reading", filename), |
611 | NULL, NULL); | |
b5aea5e1 PH |
612 | |
613 | /* If ret < 0, either the cache file does not exist, or the data it contains | |
614 | is not useful. One particular case of this is when upgrading from an older | |
615 | release of Exim in which the data was stored in a different format. We don't | |
616 | try to be clever and support both formats; we just regenerate new data in this | |
617 | case. */ | |
618 | ||
17c76198 | 619 | if (rc < 0) |
b5aea5e1 | 620 | { |
17c76198 | 621 | uschar *temp_fn; |
201f5254 | 622 | unsigned int dh_bits_gen = dh_bits; |
059ec3d9 | 623 | |
17c76198 PP |
624 | if ((PATH_MAX - Ustrlen(filename)) < 10) |
625 | return tls_error(US"Filename too long to generate replacement", | |
626 | CS filename, NULL); | |
059ec3d9 | 627 | |
17c76198 PP |
628 | temp_fn = string_copy(US "%s.XXXXXXX"); |
629 | fd = mkstemp(CS temp_fn); /* modifies temp_fn */ | |
059ec3d9 | 630 | if (fd < 0) |
17c76198 | 631 | return tls_error(US"Unable to open temp file", strerror(errno), NULL); |
059ec3d9 PH |
632 | (void)fchown(fd, exim_uid, exim_gid); /* Probably not necessary */ |
633 | ||
201f5254 PP |
634 | /* GnuTLS overshoots! |
635 | * If we ask for 2236, we might get 2237 or more. | |
636 | * But there's no way to ask GnuTLS how many bits there really are. | |
637 | * We can ask how many bits were used in a TLS session, but that's it! | |
638 | * The prime itself is hidden behind too much abstraction. | |
639 | * So we ask for less, and proceed on a wing and a prayer. | |
640 | * First attempt, subtracted 3 for 2233 and got 2240. | |
641 | */ | |
cae6e576 | 642 | if (dh_bits >= EXIM_CLIENT_DH_MIN_BITS + 10) |
201f5254 PP |
643 | { |
644 | dh_bits_gen = dh_bits - 10; | |
645 | DEBUG(D_tls) | |
646 | debug_printf("being paranoid about DH generation, make it '%d' bits'\n", | |
647 | dh_bits_gen); | |
648 | } | |
649 | ||
650 | DEBUG(D_tls) | |
651 | debug_printf("requesting generation of %d bit Diffie-Hellman prime ...\n", | |
652 | dh_bits_gen); | |
653 | rc = gnutls_dh_params_generate2(dh_server_params, dh_bits_gen); | |
17c76198 PP |
654 | exim_gnutls_err_check(US"gnutls_dh_params_generate2"); |
655 | ||
656 | /* gnutls_dh_params_export_pkcs3() will tell us the exact size, every time, | |
657 | and I confirmed that a NULL call to get the size first is how the GnuTLS | |
658 | sample apps handle this. */ | |
659 | ||
660 | sz = 0; | |
661 | m.data = NULL; | |
662 | rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, | |
663 | m.data, &sz); | |
664 | if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) | |
665 | exim_gnutls_err_check(US"gnutls_dh_params_export_pkcs3(NULL) sizing"); | |
666 | m.size = sz; | |
b5aea5e1 PH |
667 | m.data = malloc(m.size); |
668 | if (m.data == NULL) | |
17c76198 | 669 | return tls_error(US"memory allocation failed", strerror(errno), NULL); |
1f00591e | 670 | /* this will return a size 1 less than the allocation size above */ |
17c76198 | 671 | rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, |
1f00591e | 672 | m.data, &sz); |
17c76198 PP |
673 | if (rc != GNUTLS_E_SUCCESS) |
674 | { | |
675 | free(m.data); | |
676 | exim_gnutls_err_check(US"gnutls_dh_params_export_pkcs3() real"); | |
677 | } | |
1f00591e | 678 | m.size = sz; /* shrink by 1, probably */ |
059ec3d9 | 679 | |
17c76198 PP |
680 | sz = write_to_fd_buf(fd, m.data, (size_t) m.size); |
681 | if (sz != m.size) | |
682 | { | |
683 | free(m.data); | |
684 | return tls_error(US"TLS cache write D-H params failed", | |
685 | strerror(errno), NULL); | |
686 | } | |
b5aea5e1 | 687 | free(m.data); |
17c76198 PP |
688 | sz = write_to_fd_buf(fd, US"\n", 1); |
689 | if (sz != 1) | |
690 | return tls_error(US"TLS cache write D-H params final newline failed", | |
691 | strerror(errno), NULL); | |
692 | ||
693 | rc = close(fd); | |
694 | if (rc) | |
695 | return tls_error(US"TLS cache write close() failed", | |
696 | strerror(errno), NULL); | |
059ec3d9 | 697 | |
17c76198 PP |
698 | if (Urename(temp_fn, filename) < 0) |
699 | return tls_error(string_sprintf("failed to rename \"%s\" as \"%s\"", | |
700 | temp_fn, filename), strerror(errno), NULL); | |
059ec3d9 | 701 | |
17c76198 | 702 | DEBUG(D_tls) debug_printf("wrote D-H parameters to file \"%s\"\n", filename); |
059ec3d9 PH |
703 | } |
704 | ||
17c76198 | 705 | DEBUG(D_tls) debug_printf("initialized server D-H parameters\n"); |
059ec3d9 PH |
706 | return OK; |
707 | } | |
708 | ||
709 | ||
710 | ||
711 | ||
712 | /************************************************* | |
17c76198 | 713 | * Variables re-expanded post-SNI * |
059ec3d9 PH |
714 | *************************************************/ |
715 | ||
17c76198 PP |
716 | /* Called from both server and client code, via tls_init(), and also from |
717 | the SNI callback after receiving an SNI, if tls_certificate includes "tls_sni". | |
718 | ||
719 | We can tell the two apart by state->received_sni being non-NULL in callback. | |
720 | ||
721 | The callback should not call us unless state->trigger_sni_changes is true, | |
722 | which we are responsible for setting on the first pass through. | |
059ec3d9 PH |
723 | |
724 | Arguments: | |
17c76198 | 725 | state exim_gnutls_state_st * |
059ec3d9 PH |
726 | |
727 | Returns: OK/DEFER/FAIL | |
728 | */ | |
729 | ||
730 | static int | |
17c76198 | 731 | tls_expand_session_files(exim_gnutls_state_st *state) |
059ec3d9 | 732 | { |
1365611d | 733 | struct stat statbuf; |
059ec3d9 | 734 | int rc; |
17c76198 PP |
735 | const host_item *host = state->host; /* macro should be reconsidered? */ |
736 | uschar *saved_tls_certificate = NULL; | |
737 | uschar *saved_tls_privatekey = NULL; | |
738 | uschar *saved_tls_verify_certificates = NULL; | |
739 | uschar *saved_tls_crl = NULL; | |
740 | int cert_count; | |
741 | ||
742 | /* We check for tls_sni *before* expansion. */ | |
2b4a568d | 743 | if (!host) /* server */ |
17c76198 PP |
744 | { |
745 | if (!state->received_sni) | |
746 | { | |
d9b2312b JH |
747 | if (state->tls_certificate && |
748 | (Ustrstr(state->tls_certificate, US"tls_sni") || | |
749 | Ustrstr(state->tls_certificate, US"tls_in_sni") || | |
750 | Ustrstr(state->tls_certificate, US"tls_out_sni") | |
751 | )) | |
17c76198 PP |
752 | { |
753 | DEBUG(D_tls) debug_printf("We will re-expand TLS session files if we receive SNI.\n"); | |
754 | state->trigger_sni_changes = TRUE; | |
755 | } | |
756 | } | |
757 | else | |
758 | { | |
1365611d | 759 | /* useful for debugging */ |
17c76198 PP |
760 | saved_tls_certificate = state->exp_tls_certificate; |
761 | saved_tls_privatekey = state->exp_tls_privatekey; | |
762 | saved_tls_verify_certificates = state->exp_tls_verify_certificates; | |
763 | saved_tls_crl = state->exp_tls_crl; | |
764 | } | |
765 | } | |
059ec3d9 | 766 | |
1365611d PP |
767 | rc = gnutls_certificate_allocate_credentials(&state->x509_cred); |
768 | exim_gnutls_err_check(US"gnutls_certificate_allocate_credentials"); | |
769 | ||
17c76198 PP |
770 | /* remember: expand_check_tlsvar() is expand_check() but fiddling with |
771 | state members, assuming consistent naming; and expand_check() returns | |
772 | false if expansion failed, unless expansion was forced to fail. */ | |
059ec3d9 | 773 | |
17c76198 PP |
774 | /* check if we at least have a certificate, before doing expensive |
775 | D-H generation. */ | |
059ec3d9 | 776 | |
17c76198 PP |
777 | if (!expand_check_tlsvar(tls_certificate)) |
778 | return DEFER; | |
059ec3d9 | 779 | |
17c76198 | 780 | /* certificate is mandatory in server, optional in client */ |
059ec3d9 | 781 | |
17c76198 PP |
782 | if ((state->exp_tls_certificate == NULL) || |
783 | (*state->exp_tls_certificate == '\0')) | |
784 | { | |
2b4a568d | 785 | if (!host) |
17c76198 PP |
786 | return tls_error(US"no TLS server certificate is specified", NULL, NULL); |
787 | else | |
788 | DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n"); | |
789 | } | |
059ec3d9 | 790 | |
17c76198 | 791 | if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey)) |
059ec3d9 PH |
792 | return DEFER; |
793 | ||
17c76198 PP |
794 | /* tls_privatekey is optional, defaulting to same file as certificate */ |
795 | ||
796 | if (state->tls_privatekey == NULL || *state->tls_privatekey == '\0') | |
059ec3d9 | 797 | { |
17c76198 PP |
798 | state->tls_privatekey = state->tls_certificate; |
799 | state->exp_tls_privatekey = state->exp_tls_certificate; | |
059ec3d9 | 800 | } |
c91535f3 | 801 | |
059ec3d9 | 802 | |
17c76198 | 803 | if (state->exp_tls_certificate && *state->exp_tls_certificate) |
059ec3d9 PH |
804 | { |
805 | DEBUG(D_tls) debug_printf("certificate file = %s\nkey file = %s\n", | |
17c76198 PP |
806 | state->exp_tls_certificate, state->exp_tls_privatekey); |
807 | ||
808 | if (state->received_sni) | |
de365ded | 809 | { |
17c76198 PP |
810 | if ((Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0) && |
811 | (Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0)) | |
812 | { | |
b34fc30c | 813 | DEBUG(D_tls) debug_printf("TLS SNI: cert and key unchanged\n"); |
17c76198 PP |
814 | } |
815 | else | |
816 | { | |
b34fc30c | 817 | DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair.\n"); |
17c76198 | 818 | } |
8e669ac1 | 819 | } |
059ec3d9 | 820 | |
1365611d PP |
821 | rc = gnutls_certificate_set_x509_key_file(state->x509_cred, |
822 | CS state->exp_tls_certificate, CS state->exp_tls_privatekey, | |
823 | GNUTLS_X509_FMT_PEM); | |
824 | exim_gnutls_err_check( | |
825 | string_sprintf("cert/key setup: cert=%s key=%s", | |
826 | state->exp_tls_certificate, state->exp_tls_privatekey)); | |
827 | DEBUG(D_tls) debug_printf("TLS: cert/key registered\n"); | |
b34fc30c | 828 | } /* tls_certificate */ |
059ec3d9 | 829 | |
2b4a568d JH |
830 | |
831 | /* Set the OCSP stapling server info */ | |
832 | ||
f2de3a33 | 833 | #ifndef DISABLE_OCSP |
2b4a568d JH |
834 | if ( !host /* server */ |
835 | && tls_ocsp_file | |
836 | ) | |
837 | { | |
9196d5bf JH |
838 | if (gnutls_buggy_ocsp) |
839 | { | |
840 | DEBUG(D_tls) debug_printf("GnuTLS library is buggy for OCSP; avoiding\n"); | |
841 | } | |
842 | else | |
843 | { | |
844 | if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", | |
845 | &state->exp_tls_ocsp_file)) | |
846 | return DEFER; | |
2b4a568d | 847 | |
9196d5bf JH |
848 | /* Use the full callback method for stapling just to get observability. |
849 | More efficient would be to read the file once only, if it never changed | |
850 | (due to SNI). Would need restart on file update, or watch datestamp. */ | |
44662487 | 851 | |
9196d5bf JH |
852 | gnutls_certificate_set_ocsp_status_request_function(state->x509_cred, |
853 | server_ocsp_stapling_cb, state->exp_tls_ocsp_file); | |
2b4a568d | 854 | |
9196d5bf JH |
855 | DEBUG(D_tls) debug_printf("OCSP response file = %s\n", state->exp_tls_ocsp_file); |
856 | } | |
2b4a568d JH |
857 | } |
858 | #endif | |
859 | ||
860 | ||
059ec3d9 PH |
861 | /* Set the trusted CAs file if one is provided, and then add the CRL if one is |
862 | provided. Experiment shows that, if the certificate file is empty, an unhelpful | |
863 | error message is provided. However, if we just refrain from setting anything up | |
864 | in that case, certificate verification fails, which seems to be the correct | |
865 | behaviour. */ | |
866 | ||
610ff438 | 867 | if (state->tls_verify_certificates && *state->tls_verify_certificates) |
059ec3d9 | 868 | { |
17c76198 | 869 | if (!expand_check_tlsvar(tls_verify_certificates)) |
059ec3d9 | 870 | return DEFER; |
610ff438 JH |
871 | #ifndef SUPPORT_SYSDEFAULT_CABUNDLE |
872 | if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) | |
873 | state->exp_tls_verify_certificates = NULL; | |
874 | #endif | |
17c76198 PP |
875 | if (state->tls_crl && *state->tls_crl) |
876 | if (!expand_check_tlsvar(tls_crl)) | |
877 | return DEFER; | |
059ec3d9 | 878 | |
1365611d PP |
879 | if (!(state->exp_tls_verify_certificates && |
880 | *state->exp_tls_verify_certificates)) | |
b34fc30c PP |
881 | { |
882 | DEBUG(D_tls) | |
1365611d PP |
883 | debug_printf("TLS: tls_verify_certificates expanded empty, ignoring\n"); |
884 | /* With no tls_verify_certificates, we ignore tls_crl too */ | |
17c76198 | 885 | return OK; |
b34fc30c | 886 | } |
1365611d | 887 | } |
83e2f8a2 PP |
888 | else |
889 | { | |
890 | DEBUG(D_tls) | |
891 | debug_printf("TLS: tls_verify_certificates not set or empty, ignoring\n"); | |
892 | return OK; | |
893 | } | |
17c76198 | 894 | |
cb1d7830 JH |
895 | #ifdef SUPPORT_SYSDEFAULT_CABUNDLE |
896 | if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) | |
897 | cert_count = gnutls_certificate_set_x509_system_trust(state->x509_cred); | |
898 | else | |
899 | #endif | |
1365611d | 900 | { |
cb1d7830 JH |
901 | if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0) |
902 | { | |
903 | log_write(0, LOG_MAIN|LOG_PANIC, "could not stat %s " | |
904 | "(tls_verify_certificates): %s", state->exp_tls_verify_certificates, | |
905 | strerror(errno)); | |
906 | return DEFER; | |
907 | } | |
17c76198 | 908 | |
a7fec7a7 | 909 | #ifndef SUPPORT_CA_DIR |
cb1d7830 JH |
910 | /* The test suite passes in /dev/null; we could check for that path explicitly, |
911 | but who knows if someone has some weird FIFO which always dumps some certs, or | |
912 | other weirdness. The thing we really want to check is that it's not a | |
913 | directory, since while OpenSSL supports that, GnuTLS does not. | |
914 | So s/!S_ISREG/S_ISDIR/ and change some messsaging ... */ | |
915 | if (S_ISDIR(statbuf.st_mode)) | |
916 | { | |
917 | DEBUG(D_tls) | |
918 | debug_printf("verify certificates path is a dir: \"%s\"\n", | |
919 | state->exp_tls_verify_certificates); | |
920 | log_write(0, LOG_MAIN|LOG_PANIC, | |
921 | "tls_verify_certificates \"%s\" is a directory", | |
922 | state->exp_tls_verify_certificates); | |
923 | return DEFER; | |
924 | } | |
a7fec7a7 | 925 | #endif |
059ec3d9 | 926 | |
cb1d7830 JH |
927 | DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n", |
928 | state->exp_tls_verify_certificates, statbuf.st_size); | |
059ec3d9 | 929 | |
cb1d7830 JH |
930 | if (statbuf.st_size == 0) |
931 | { | |
932 | DEBUG(D_tls) | |
933 | debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n"); | |
934 | return OK; | |
935 | } | |
059ec3d9 | 936 | |
cb1d7830 | 937 | cert_count = |
a7fec7a7 JH |
938 | |
939 | #ifdef SUPPORT_CA_DIR | |
cb1d7830 JH |
940 | (statbuf.st_mode & S_IFMT) == S_IFDIR |
941 | ? | |
942 | gnutls_certificate_set_x509_trust_dir(state->x509_cred, | |
943 | CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM) | |
944 | : | |
a7fec7a7 | 945 | #endif |
cb1d7830 JH |
946 | gnutls_certificate_set_x509_trust_file(state->x509_cred, |
947 | CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM); | |
948 | } | |
a7fec7a7 | 949 | |
1365611d PP |
950 | if (cert_count < 0) |
951 | { | |
952 | rc = cert_count; | |
cb1d7830 | 953 | exim_gnutls_err_check(US"setting certificate trust"); |
1365611d PP |
954 | } |
955 | DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", cert_count); | |
059ec3d9 | 956 | |
5c8cda3a PP |
957 | if (state->tls_crl && *state->tls_crl && |
958 | state->exp_tls_crl && *state->exp_tls_crl) | |
1365611d | 959 | { |
5c8cda3a PP |
960 | DEBUG(D_tls) debug_printf("loading CRL file = %s\n", state->exp_tls_crl); |
961 | cert_count = gnutls_certificate_set_x509_crl_file(state->x509_cred, | |
962 | CS state->exp_tls_crl, GNUTLS_X509_FMT_PEM); | |
963 | if (cert_count < 0) | |
1365611d | 964 | { |
5c8cda3a | 965 | rc = cert_count; |
1365611d PP |
966 | exim_gnutls_err_check(US"gnutls_certificate_set_x509_crl_file"); |
967 | } | |
5c8cda3a | 968 | DEBUG(D_tls) debug_printf("Processed %d CRLs.\n", cert_count); |
1365611d | 969 | } |
059ec3d9 | 970 | |
059ec3d9 PH |
971 | return OK; |
972 | } | |
973 | ||
974 | ||
975 | ||
976 | ||
1365611d PP |
977 | /************************************************* |
978 | * Set X.509 state variables * | |
979 | *************************************************/ | |
980 | ||
981 | /* In GnuTLS, the registered cert/key are not replaced by a later | |
982 | set of a cert/key, so for SNI support we need a whole new x509_cred | |
983 | structure. Which means various other non-re-expanded pieces of state | |
984 | need to be re-set in the new struct, so the setting logic is pulled | |
985 | out to this. | |
986 | ||
987 | Arguments: | |
988 | state exim_gnutls_state_st * | |
989 | ||
990 | Returns: OK/DEFER/FAIL | |
991 | */ | |
992 | ||
993 | static int | |
994 | tls_set_remaining_x509(exim_gnutls_state_st *state) | |
995 | { | |
996 | int rc; | |
997 | const host_item *host = state->host; /* macro should be reconsidered? */ | |
998 | ||
999 | /* Create D-H parameters, or read them from the cache file. This function does | |
1000 | its own SMTP error messaging. This only happens for the server, TLS D-H ignores | |
1001 | client-side params. */ | |
1002 | ||
1003 | if (!state->host) | |
1004 | { | |
1005 | if (!dh_server_params) | |
1006 | { | |
1007 | rc = init_server_dh(); | |
1008 | if (rc != OK) return rc; | |
1009 | } | |
1010 | gnutls_certificate_set_dh_params(state->x509_cred, dh_server_params); | |
1011 | } | |
1012 | ||
1013 | /* Link the credentials to the session. */ | |
1014 | ||
1015 | rc = gnutls_credentials_set(state->session, GNUTLS_CRD_CERTIFICATE, state->x509_cred); | |
1016 | exim_gnutls_err_check(US"gnutls_credentials_set"); | |
1017 | ||
1018 | return OK; | |
1019 | } | |
1020 | ||
059ec3d9 | 1021 | /************************************************* |
17c76198 | 1022 | * Initialize for GnuTLS * |
059ec3d9 PH |
1023 | *************************************************/ |
1024 | ||
9196d5bf | 1025 | |
4fb7df6d JH |
1026 | #ifndef DISABLE_OCSP |
1027 | ||
9196d5bf JH |
1028 | static BOOL |
1029 | tls_is_buggy_ocsp(void) | |
1030 | { | |
1031 | const uschar * s; | |
1032 | uschar maj, mid, mic; | |
1033 | ||
1034 | s = CUS gnutls_check_version(NULL); | |
1035 | maj = atoi(CCS s); | |
1036 | if (maj == 3) | |
1037 | { | |
1038 | while (*s && *s != '.') s++; | |
1039 | mid = atoi(CCS ++s); | |
1040 | if (mid <= 2) | |
1041 | return TRUE; | |
1042 | else if (mid >= 5) | |
1043 | return FALSE; | |
1044 | else | |
1045 | { | |
1046 | while (*s && *s != '.') s++; | |
1047 | mic = atoi(CCS ++s); | |
1048 | return mic <= (mid == 3 ? 16 : 3); | |
1049 | } | |
1050 | } | |
1051 | return FALSE; | |
1052 | } | |
1053 | ||
4fb7df6d | 1054 | #endif |
9196d5bf JH |
1055 | |
1056 | ||
17c76198 PP |
1057 | /* Called from both server and client code. In the case of a server, errors |
1058 | before actual TLS negotiation return DEFER. | |
059ec3d9 PH |
1059 | |
1060 | Arguments: | |
17c76198 PP |
1061 | host connected host, if client; NULL if server |
1062 | certificate certificate file | |
1063 | privatekey private key file | |
1064 | sni TLS SNI to send, sometimes when client; else NULL | |
1065 | cas CA certs file | |
1066 | crl CRL file | |
1067 | require_ciphers tls_require_ciphers setting | |
817d9f57 | 1068 | caller_state returned state-info structure |
059ec3d9 | 1069 | |
17c76198 | 1070 | Returns: OK/DEFER/FAIL |
059ec3d9 PH |
1071 | */ |
1072 | ||
17c76198 PP |
1073 | static int |
1074 | tls_init( | |
1075 | const host_item *host, | |
1076 | const uschar *certificate, | |
1077 | const uschar *privatekey, | |
1078 | const uschar *sni, | |
1079 | const uschar *cas, | |
1080 | const uschar *crl, | |
1081 | const uschar *require_ciphers, | |
1082 | exim_gnutls_state_st **caller_state) | |
059ec3d9 | 1083 | { |
17c76198 PP |
1084 | exim_gnutls_state_st *state; |
1085 | int rc; | |
1086 | size_t sz; | |
1087 | const char *errpos; | |
1088 | uschar *p; | |
1089 | BOOL want_default_priorities; | |
1090 | ||
1091 | if (!exim_gnutls_base_init_done) | |
059ec3d9 | 1092 | { |
17c76198 PP |
1093 | DEBUG(D_tls) debug_printf("GnuTLS global init required.\n"); |
1094 | ||
a5f239e4 PP |
1095 | #ifdef HAVE_GNUTLS_PKCS11 |
1096 | /* By default, gnutls_global_init will init PKCS11 support in auto mode, | |
1097 | which loads modules from a config file, which sounds good and may be wanted | |
1098 | by some sysadmin, but also means in common configurations that GNOME keyring | |
1099 | environment variables are used and so breaks for users calling mailq. | |
1100 | To prevent this, we init PKCS11 first, which is the documented approach. */ | |
2519e60d | 1101 | if (!gnutls_allow_auto_pkcs11) |
a5f239e4 PP |
1102 | { |
1103 | rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL); | |
1104 | exim_gnutls_err_check(US"gnutls_pkcs11_init"); | |
1105 | } | |
1106 | #endif | |
1107 | ||
17c76198 PP |
1108 | rc = gnutls_global_init(); |
1109 | exim_gnutls_err_check(US"gnutls_global_init"); | |
1110 | ||
1111 | #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 | |
1112 | DEBUG(D_tls) | |
059ec3d9 | 1113 | { |
17c76198 PP |
1114 | gnutls_global_set_log_function(exim_gnutls_logger_cb); |
1115 | /* arbitrarily chosen level; bump upto 9 for more */ | |
1116 | gnutls_global_set_log_level(EXIM_GNUTLS_LIBRARY_LOG_LEVEL); | |
059ec3d9 | 1117 | } |
17c76198 PP |
1118 | #endif |
1119 | ||
4fb7df6d JH |
1120 | #ifndef DISABLE_OCSP |
1121 | if (tls_ocsp_file && (gnutls_buggy_ocsp = tls_is_buggy_ocsp())) | |
9196d5bf | 1122 | log_write(0, LOG_MAIN, "OCSP unusable with this GnuTLS library version"); |
4fb7df6d | 1123 | #endif |
9196d5bf | 1124 | |
17c76198 | 1125 | exim_gnutls_base_init_done = TRUE; |
059ec3d9 | 1126 | } |
059ec3d9 | 1127 | |
17c76198 PP |
1128 | if (host) |
1129 | { | |
1130 | state = &state_client; | |
1131 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); | |
817d9f57 | 1132 | state->tlsp = &tls_out; |
17c76198 PP |
1133 | DEBUG(D_tls) debug_printf("initialising GnuTLS client session\n"); |
1134 | rc = gnutls_init(&state->session, GNUTLS_CLIENT); | |
1135 | } | |
1136 | else | |
1137 | { | |
1138 | state = &state_server; | |
1139 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); | |
817d9f57 | 1140 | state->tlsp = &tls_in; |
17c76198 PP |
1141 | DEBUG(D_tls) debug_printf("initialising GnuTLS server session\n"); |
1142 | rc = gnutls_init(&state->session, GNUTLS_SERVER); | |
1143 | } | |
1144 | exim_gnutls_err_check(US"gnutls_init"); | |
059ec3d9 | 1145 | |
17c76198 | 1146 | state->host = host; |
059ec3d9 | 1147 | |
17c76198 PP |
1148 | state->tls_certificate = certificate; |
1149 | state->tls_privatekey = privatekey; | |
5779e6aa | 1150 | state->tls_require_ciphers = require_ciphers; |
17c76198 PP |
1151 | state->tls_sni = sni; |
1152 | state->tls_verify_certificates = cas; | |
1153 | state->tls_crl = crl; | |
059ec3d9 | 1154 | |
17c76198 PP |
1155 | /* This handles the variables that might get re-expanded after TLS SNI; |
1156 | that's tls_certificate, tls_privatekey, tls_verify_certificates, tls_crl */ | |
059ec3d9 | 1157 | |
17c76198 PP |
1158 | DEBUG(D_tls) |
1159 | debug_printf("Expanding various TLS configuration options for session credentials.\n"); | |
1160 | rc = tls_expand_session_files(state); | |
1161 | if (rc != OK) return rc; | |
059ec3d9 | 1162 | |
1365611d PP |
1163 | /* These are all other parts of the x509_cred handling, since SNI in GnuTLS |
1164 | requires a new structure afterwards. */ | |
83da1223 | 1165 | |
1365611d PP |
1166 | rc = tls_set_remaining_x509(state); |
1167 | if (rc != OK) return rc; | |
83da1223 | 1168 | |
17c76198 PP |
1169 | /* set SNI in client, only */ |
1170 | if (host) | |
1171 | { | |
0df4ab80 | 1172 | if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni)) |
17c76198 | 1173 | return DEFER; |
0df4ab80 | 1174 | if (state->tlsp->sni && *state->tlsp->sni) |
17c76198 PP |
1175 | { |
1176 | DEBUG(D_tls) | |
0df4ab80 JH |
1177 | debug_printf("Setting TLS client SNI to \"%s\"\n", state->tlsp->sni); |
1178 | sz = Ustrlen(state->tlsp->sni); | |
17c76198 | 1179 | rc = gnutls_server_name_set(state->session, |
0df4ab80 | 1180 | GNUTLS_NAME_DNS, state->tlsp->sni, sz); |
17c76198 PP |
1181 | exim_gnutls_err_check(US"gnutls_server_name_set"); |
1182 | } | |
1183 | } | |
1184 | else if (state->tls_sni) | |
1185 | DEBUG(D_tls) debug_printf("*** PROBABLY A BUG *** " \ | |
1186 | "have an SNI set for a client [%s]\n", state->tls_sni); | |
83da1223 | 1187 | |
17c76198 | 1188 | /* This is the priority string support, |
42bfef1e | 1189 | http://www.gnutls.org/manual/html_node/Priority-Strings.html |
17c76198 PP |
1190 | and replaces gnutls_require_kx, gnutls_require_mac & gnutls_require_protocols. |
1191 | This was backwards incompatible, but means Exim no longer needs to track | |
1192 | all algorithms and provide string forms for them. */ | |
83da1223 | 1193 | |
17c76198 | 1194 | want_default_priorities = TRUE; |
83da1223 | 1195 | |
17c76198 | 1196 | if (state->tls_require_ciphers && *state->tls_require_ciphers) |
83da1223 | 1197 | { |
17c76198 PP |
1198 | if (!expand_check_tlsvar(tls_require_ciphers)) |
1199 | return DEFER; | |
1200 | if (state->exp_tls_require_ciphers && *state->exp_tls_require_ciphers) | |
83da1223 | 1201 | { |
17c76198 PP |
1202 | DEBUG(D_tls) debug_printf("GnuTLS session cipher/priority \"%s\"\n", |
1203 | state->exp_tls_require_ciphers); | |
1204 | ||
1205 | rc = gnutls_priority_init(&state->priority_cache, | |
1206 | CS state->exp_tls_require_ciphers, &errpos); | |
1207 | want_default_priorities = FALSE; | |
1208 | p = state->exp_tls_require_ciphers; | |
83da1223 PH |
1209 | } |
1210 | } | |
17c76198 PP |
1211 | if (want_default_priorities) |
1212 | { | |
83e2f8a2 PP |
1213 | DEBUG(D_tls) |
1214 | debug_printf("GnuTLS using default session cipher/priority \"%s\"\n", | |
1215 | exim_default_gnutls_priority); | |
17c76198 PP |
1216 | rc = gnutls_priority_init(&state->priority_cache, |
1217 | exim_default_gnutls_priority, &errpos); | |
1218 | p = US exim_default_gnutls_priority; | |
1219 | } | |
83da1223 | 1220 | |
17c76198 PP |
1221 | exim_gnutls_err_check(string_sprintf( |
1222 | "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"", | |
1223 | p, errpos - CS p, errpos)); | |
1224 | ||
1225 | rc = gnutls_priority_set(state->session, state->priority_cache); | |
1226 | exim_gnutls_err_check(US"gnutls_priority_set"); | |
1227 | ||
1228 | gnutls_db_set_cache_expiration(state->session, ssl_session_timeout); | |
1229 | ||
1230 | /* Reduce security in favour of increased compatibility, if the admin | |
1231 | decides to make that trade-off. */ | |
1232 | if (gnutls_compat_mode) | |
83da1223 | 1233 | { |
17c76198 PP |
1234 | #if LIBGNUTLS_VERSION_NUMBER >= 0x020104 |
1235 | DEBUG(D_tls) debug_printf("lowering GnuTLS security, compatibility mode\n"); | |
1236 | gnutls_session_enable_compatibility_mode(state->session); | |
1237 | #else | |
1238 | DEBUG(D_tls) debug_printf("Unable to set gnutls_compat_mode - GnuTLS version too old\n"); | |
1239 | #endif | |
83da1223 PH |
1240 | } |
1241 | ||
17c76198 | 1242 | *caller_state = state; |
17c76198 | 1243 | return OK; |
83da1223 PH |
1244 | } |
1245 | ||
1246 | ||
1247 | ||
059ec3d9 | 1248 | /************************************************* |
17c76198 | 1249 | * Extract peer information * |
059ec3d9 PH |
1250 | *************************************************/ |
1251 | ||
17c76198 | 1252 | /* Called from both server and client code. |
4fe99a6c PP |
1253 | Only this is allowed to set state->peerdn and state->have_set_peerdn |
1254 | and we use that to detect double-calls. | |
059ec3d9 | 1255 | |
75fe387d PP |
1256 | NOTE: the state blocks last while the TLS connection is up, which is fine |
1257 | for logging in the server side, but for the client side, we log after teardown | |
1258 | in src/deliver.c. While the session is up, we can twist about states and | |
1259 | repoint tls_* globals, but those variables used for logging or other variable | |
1260 | expansion that happens _after_ delivery need to have a longer life-time. | |
1261 | ||
1262 | So for those, we get the data from POOL_PERM; the re-invoke guard keeps us from | |
1263 | doing this more than once per generation of a state context. We set them in | |
1264 | the state context, and repoint tls_* to them. After the state goes away, the | |
1265 | tls_* copies of the pointers remain valid and client delivery logging is happy. | |
1266 | ||
1267 | tls_certificate_verified is a BOOL, so the tls_peerdn and tls_cipher issues | |
1268 | don't apply. | |
1269 | ||
059ec3d9 | 1270 | Arguments: |
17c76198 | 1271 | state exim_gnutls_state_st * |
059ec3d9 | 1272 | |
17c76198 | 1273 | Returns: OK/DEFER/FAIL |
059ec3d9 PH |
1274 | */ |
1275 | ||
17c76198 PP |
1276 | static int |
1277 | peer_status(exim_gnutls_state_st *state) | |
059ec3d9 | 1278 | { |
75fe387d | 1279 | uschar cipherbuf[256]; |
27f19eb4 | 1280 | const gnutls_datum_t *cert_list; |
75fe387d | 1281 | int old_pool, rc; |
17c76198 | 1282 | unsigned int cert_list_size = 0; |
4fe99a6c PP |
1283 | gnutls_protocol_t protocol; |
1284 | gnutls_cipher_algorithm_t cipher; | |
1285 | gnutls_kx_algorithm_t kx; | |
1286 | gnutls_mac_algorithm_t mac; | |
17c76198 PP |
1287 | gnutls_certificate_type_t ct; |
1288 | gnutls_x509_crt_t crt; | |
4fe99a6c | 1289 | uschar *p, *dn_buf; |
17c76198 | 1290 | size_t sz; |
059ec3d9 | 1291 | |
4fe99a6c | 1292 | if (state->have_set_peerdn) |
17c76198 | 1293 | return OK; |
4fe99a6c | 1294 | state->have_set_peerdn = TRUE; |
059ec3d9 | 1295 | |
4fe99a6c | 1296 | state->peerdn = NULL; |
059ec3d9 | 1297 | |
4fe99a6c PP |
1298 | /* tls_cipher */ |
1299 | cipher = gnutls_cipher_get(state->session); | |
1300 | protocol = gnutls_protocol_get_version(state->session); | |
1301 | mac = gnutls_mac_get(state->session); | |
1302 | kx = gnutls_kx_get(state->session); | |
1303 | ||
75fe387d | 1304 | string_format(cipherbuf, sizeof(cipherbuf), |
4fe99a6c PP |
1305 | "%s:%s:%d", |
1306 | gnutls_protocol_get_name(protocol), | |
1307 | gnutls_cipher_suite_get_name(kx, cipher, mac), | |
1308 | (int) gnutls_cipher_get_key_size(cipher) * 8); | |
1309 | ||
1310 | /* I don't see a way that spaces could occur, in the current GnuTLS | |
1311 | code base, but it was a concern in the old code and perhaps older GnuTLS | |
1312 | releases did return "TLS 1.0"; play it safe, just in case. */ | |
75fe387d | 1313 | for (p = cipherbuf; *p != '\0'; ++p) |
4fe99a6c PP |
1314 | if (isspace(*p)) |
1315 | *p = '-'; | |
75fe387d PP |
1316 | old_pool = store_pool; |
1317 | store_pool = POOL_PERM; | |
1318 | state->ciphersuite = string_copy(cipherbuf); | |
1319 | store_pool = old_pool; | |
817d9f57 | 1320 | state->tlsp->cipher = state->ciphersuite; |
4fe99a6c PP |
1321 | |
1322 | /* tls_peerdn */ | |
17c76198 | 1323 | cert_list = gnutls_certificate_get_peers(state->session, &cert_list_size); |
83da1223 | 1324 | |
17c76198 PP |
1325 | if (cert_list == NULL || cert_list_size == 0) |
1326 | { | |
17c76198 PP |
1327 | DEBUG(D_tls) debug_printf("TLS: no certificate from peer (%p & %d)\n", |
1328 | cert_list, cert_list_size); | |
e51c7be2 | 1329 | if (state->verify_requirement >= VERIFY_REQUIRED) |
17c76198 PP |
1330 | return tls_error(US"certificate verification failed", |
1331 | "no certificate received from peer", state->host); | |
1332 | return OK; | |
1333 | } | |
059ec3d9 | 1334 | |
17c76198 PP |
1335 | ct = gnutls_certificate_type_get(state->session); |
1336 | if (ct != GNUTLS_CRT_X509) | |
059ec3d9 | 1337 | { |
17c76198 | 1338 | const char *ctn = gnutls_certificate_type_get_name(ct); |
17c76198 PP |
1339 | DEBUG(D_tls) |
1340 | debug_printf("TLS: peer cert not X.509 but instead \"%s\"\n", ctn); | |
e51c7be2 | 1341 | if (state->verify_requirement >= VERIFY_REQUIRED) |
17c76198 PP |
1342 | return tls_error(US"certificate verification not possible, unhandled type", |
1343 | ctn, state->host); | |
1344 | return OK; | |
83da1223 | 1345 | } |
059ec3d9 | 1346 | |
e51c7be2 JH |
1347 | #define exim_gnutls_peer_err(Label) \ |
1348 | do { \ | |
1349 | if (rc != GNUTLS_E_SUCCESS) \ | |
1350 | { \ | |
1351 | DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", \ | |
1352 | (Label), gnutls_strerror(rc)); \ | |
1353 | if (state->verify_requirement >= VERIFY_REQUIRED) \ | |
1354 | return tls_error((Label), gnutls_strerror(rc), state->host); \ | |
1355 | return OK; \ | |
1356 | } \ | |
1357 | } while (0) | |
17c76198 | 1358 | |
9d1c15ef JH |
1359 | rc = import_cert(&cert_list[0], &crt); |
1360 | exim_gnutls_peer_err(US"cert 0"); | |
1361 | ||
1362 | state->tlsp->peercert = state->peercert = crt; | |
17c76198 | 1363 | |
17c76198 PP |
1364 | sz = 0; |
1365 | rc = gnutls_x509_crt_get_dn(crt, NULL, &sz); | |
1366 | if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) | |
83da1223 | 1367 | { |
17c76198 PP |
1368 | exim_gnutls_peer_err(US"getting size for cert DN failed"); |
1369 | return FAIL; /* should not happen */ | |
059ec3d9 | 1370 | } |
17c76198 PP |
1371 | dn_buf = store_get_perm(sz); |
1372 | rc = gnutls_x509_crt_get_dn(crt, CS dn_buf, &sz); | |
1373 | exim_gnutls_peer_err(US"failed to extract certificate DN [gnutls_x509_crt_get_dn(cert 0)]"); | |
9d1c15ef | 1374 | |
17c76198 PP |
1375 | state->peerdn = dn_buf; |
1376 | ||
1377 | return OK; | |
1378 | #undef exim_gnutls_peer_err | |
1379 | } | |
059ec3d9 | 1380 | |
059ec3d9 | 1381 | |
059ec3d9 | 1382 | |
059ec3d9 | 1383 | |
17c76198 PP |
1384 | /************************************************* |
1385 | * Verify peer certificate * | |
1386 | *************************************************/ | |
059ec3d9 | 1387 | |
17c76198 PP |
1388 | /* Called from both server and client code. |
1389 | *Should* be using a callback registered with | |
1390 | gnutls_certificate_set_verify_function() to fail the handshake if we dislike | |
1391 | the peer information, but that's too new for some OSes. | |
059ec3d9 | 1392 | |
17c76198 PP |
1393 | Arguments: |
1394 | state exim_gnutls_state_st * | |
1395 | error where to put an error message | |
059ec3d9 | 1396 | |
17c76198 PP |
1397 | Returns: |
1398 | FALSE if the session should be rejected | |
1399 | TRUE if the cert is okay or we just don't care | |
1400 | */ | |
059ec3d9 | 1401 | |
17c76198 PP |
1402 | static BOOL |
1403 | verify_certificate(exim_gnutls_state_st *state, const char **error) | |
1404 | { | |
1405 | int rc; | |
1406 | unsigned int verify; | |
1407 | ||
1408 | *error = NULL; | |
1409 | ||
0a92f87f | 1410 | if ((rc = peer_status(state)) != OK) |
e6060e2c | 1411 | { |
17c76198 | 1412 | verify = GNUTLS_CERT_INVALID; |
0a92f87f | 1413 | *error = "certificate not supplied"; |
17c76198 PP |
1414 | } |
1415 | else | |
17c76198 | 1416 | rc = gnutls_certificate_verify_peers2(state->session, &verify); |
e6060e2c | 1417 | |
17c76198 PP |
1418 | /* Handle the result of verification. INVALID seems to be set as well |
1419 | as REVOKED, but leave the test for both. */ | |
059ec3d9 | 1420 | |
e51c7be2 JH |
1421 | if (rc < 0 || |
1422 | verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED) | |
1423 | ) | |
17c76198 PP |
1424 | { |
1425 | state->peer_cert_verified = FALSE; | |
0a92f87f JH |
1426 | if (!*error) |
1427 | *error = verify & GNUTLS_CERT_REVOKED | |
1428 | ? "certificate revoked" : "certificate invalid"; | |
059ec3d9 | 1429 | |
17c76198 | 1430 | DEBUG(D_tls) |
e51c7be2 | 1431 | debug_printf("TLS certificate verification failed (%s): peerdn=\"%s\"\n", |
4fe99a6c | 1432 | *error, state->peerdn ? state->peerdn : US"<unset>"); |
059ec3d9 | 1433 | |
e51c7be2 | 1434 | if (state->verify_requirement >= VERIFY_REQUIRED) |
17c76198 | 1435 | { |
e51c7be2 JH |
1436 | gnutls_alert_send(state->session, |
1437 | GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); | |
17c76198 PP |
1438 | return FALSE; |
1439 | } | |
1440 | DEBUG(D_tls) | |
4789da3a | 1441 | debug_printf("TLS verify failure overridden (host in tls_try_verify_hosts)\n"); |
17c76198 | 1442 | } |
e51c7be2 | 1443 | |
17c76198 PP |
1444 | else |
1445 | { | |
aa2a70ba | 1446 | if (state->exp_tls_verify_cert_hostnames) |
e51c7be2 JH |
1447 | { |
1448 | int sep = 0; | |
55414b25 | 1449 | const uschar * list = state->exp_tls_verify_cert_hostnames; |
e51c7be2 JH |
1450 | uschar * name; |
1451 | while (name = string_nextinlist(&list, &sep, NULL, 0)) | |
1452 | if (gnutls_x509_crt_check_hostname(state->tlsp->peercert, CS name)) | |
1453 | break; | |
1454 | if (!name) | |
1455 | { | |
1456 | DEBUG(D_tls) | |
1457 | debug_printf("TLS certificate verification failed: cert name mismatch\n"); | |
aa2a70ba JH |
1458 | if (state->verify_requirement >= VERIFY_REQUIRED) |
1459 | { | |
1460 | gnutls_alert_send(state->session, | |
1461 | GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); | |
1462 | return FALSE; | |
1463 | } | |
1464 | return TRUE; | |
e51c7be2 JH |
1465 | } |
1466 | } | |
17c76198 | 1467 | state->peer_cert_verified = TRUE; |
e51c7be2 | 1468 | DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=\"%s\"\n", |
4fe99a6c | 1469 | state->peerdn ? state->peerdn : US"<unset>"); |
17c76198 | 1470 | } |
059ec3d9 | 1471 | |
817d9f57 | 1472 | state->tlsp->peerdn = state->peerdn; |
059ec3d9 | 1473 | |
17c76198 PP |
1474 | return TRUE; |
1475 | } | |
059ec3d9 | 1476 | |
17c76198 PP |
1477 | |
1478 | ||
1479 | ||
1480 | /* ------------------------------------------------------------------------ */ | |
1481 | /* Callbacks */ | |
1482 | ||
1483 | /* Logging function which can be registered with | |
1484 | * gnutls_global_set_log_function() | |
1485 | * gnutls_global_set_log_level() 0..9 | |
1486 | */ | |
af3498d6 | 1487 | #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 |
059ec3d9 | 1488 | static void |
17c76198 | 1489 | exim_gnutls_logger_cb(int level, const char *message) |
059ec3d9 | 1490 | { |
8c79eebf PP |
1491 | size_t len = strlen(message); |
1492 | if (len < 1) | |
1493 | { | |
1494 | DEBUG(D_tls) debug_printf("GnuTLS<%d> empty debug message\n", level); | |
1495 | return; | |
1496 | } | |
1497 | DEBUG(D_tls) debug_printf("GnuTLS<%d>: %s%s", level, message, | |
1498 | message[len-1] == '\n' ? "" : "\n"); | |
17c76198 | 1499 | } |
af3498d6 | 1500 | #endif |
059ec3d9 | 1501 | |
059ec3d9 | 1502 | |
17c76198 PP |
1503 | /* Called after client hello, should handle SNI work. |
1504 | This will always set tls_sni (state->received_sni) if available, | |
1505 | and may trigger presenting different certificates, | |
1506 | if state->trigger_sni_changes is TRUE. | |
059ec3d9 | 1507 | |
17c76198 PP |
1508 | Should be registered with |
1509 | gnutls_handshake_set_post_client_hello_function() | |
059ec3d9 | 1510 | |
17c76198 PP |
1511 | "This callback must return 0 on success or a gnutls error code to terminate the |
1512 | handshake.". | |
059ec3d9 | 1513 | |
17c76198 PP |
1514 | For inability to get SNI information, we return 0. |
1515 | We only return non-zero if re-setup failed. | |
817d9f57 | 1516 | Only used for server-side TLS. |
17c76198 | 1517 | */ |
44bbabb5 | 1518 | |
17c76198 PP |
1519 | static int |
1520 | exim_sni_handling_cb(gnutls_session_t session) | |
1521 | { | |
1522 | char sni_name[MAX_HOST_LEN]; | |
1523 | size_t data_len = MAX_HOST_LEN; | |
817d9f57 | 1524 | exim_gnutls_state_st *state = &state_server; |
17c76198 PP |
1525 | unsigned int sni_type; |
1526 | int rc, old_pool; | |
1527 | ||
1528 | rc = gnutls_server_name_get(session, sni_name, &data_len, &sni_type, 0); | |
b34fc30c PP |
1529 | if (rc != GNUTLS_E_SUCCESS) |
1530 | { | |
1531 | DEBUG(D_tls) { | |
1532 | if (rc == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) | |
1533 | debug_printf("TLS: no SNI presented in handshake.\n"); | |
1534 | else | |
1535 | debug_printf("TLS failure: gnutls_server_name_get(): %s [%d]\n", | |
1536 | gnutls_strerror(rc), rc); | |
1537 | }; | |
1538 | return 0; | |
1539 | } | |
1540 | ||
17c76198 PP |
1541 | if (sni_type != GNUTLS_NAME_DNS) |
1542 | { | |
1543 | DEBUG(D_tls) debug_printf("TLS: ignoring SNI of unhandled type %u\n", sni_type); | |
1544 | return 0; | |
1545 | } | |
44bbabb5 | 1546 | |
17c76198 PP |
1547 | /* We now have a UTF-8 string in sni_name */ |
1548 | old_pool = store_pool; | |
1549 | store_pool = POOL_PERM; | |
1550 | state->received_sni = string_copyn(US sni_name, data_len); | |
1551 | store_pool = old_pool; | |
1552 | ||
1553 | /* We set this one now so that variable expansions below will work */ | |
817d9f57 | 1554 | state->tlsp->sni = state->received_sni; |
17c76198 PP |
1555 | |
1556 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", sni_name, | |
1557 | state->trigger_sni_changes ? "" : " (unused for certificate selection)"); | |
1558 | ||
1559 | if (!state->trigger_sni_changes) | |
1560 | return 0; | |
1561 | ||
1562 | rc = tls_expand_session_files(state); | |
1563 | if (rc != OK) | |
1564 | { | |
1565 | /* If the setup of certs/etc failed before handshake, TLS would not have | |
1566 | been offered. The best we can do now is abort. */ | |
1567 | return GNUTLS_E_APPLICATION_ERROR_MIN; | |
1568 | } | |
1569 | ||
1365611d PP |
1570 | rc = tls_set_remaining_x509(state); |
1571 | if (rc != OK) return GNUTLS_E_APPLICATION_ERROR_MIN; | |
1572 | ||
1573 | return 0; | |
059ec3d9 PH |
1574 | } |
1575 | ||
1576 | ||
1577 | ||
f2de3a33 | 1578 | #ifndef DISABLE_OCSP |
44662487 JH |
1579 | |
1580 | static int | |
1581 | server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, | |
1582 | gnutls_datum_t * ocsp_response) | |
1583 | { | |
1584 | int ret; | |
1585 | ||
44662487 JH |
1586 | if ((ret = gnutls_load_file(ptr, ocsp_response)) < 0) |
1587 | { | |
1588 | DEBUG(D_tls) debug_printf("Failed to load ocsp stapling file %s\n", | |
1589 | (char *)ptr); | |
018058b2 | 1590 | tls_in.ocsp = OCSP_NOT_RESP; |
44662487 JH |
1591 | return GNUTLS_E_NO_CERTIFICATE_STATUS; |
1592 | } | |
1593 | ||
018058b2 | 1594 | tls_in.ocsp = OCSP_VFY_NOT_TRIED; |
44662487 JH |
1595 | return 0; |
1596 | } | |
1597 | ||
1598 | #endif | |
1599 | ||
1600 | ||
0cbf2b82 | 1601 | #ifndef DISABLE_EVENT |
a7538db1 JH |
1602 | /* |
1603 | We use this callback to get observability and detail-level control | |
723fe533 JH |
1604 | for an exim TLS connection (either direction), raising a tls:cert event |
1605 | for each cert in the chain presented by the peer. Any event | |
a7538db1 JH |
1606 | can deny verification. |
1607 | ||
1608 | Return 0 for the handshake to continue or non-zero to terminate. | |
1609 | */ | |
1610 | ||
1611 | static int | |
723fe533 | 1612 | verify_cb(gnutls_session_t session) |
a7538db1 | 1613 | { |
27f19eb4 | 1614 | const gnutls_datum_t * cert_list; |
a7538db1 JH |
1615 | unsigned int cert_list_size = 0; |
1616 | gnutls_x509_crt_t crt; | |
1617 | int rc; | |
b30275b8 | 1618 | uschar * yield; |
a7538db1 JH |
1619 | exim_gnutls_state_st * state = gnutls_session_get_ptr(session); |
1620 | ||
1621 | cert_list = gnutls_certificate_get_peers(session, &cert_list_size); | |
1622 | if (cert_list) | |
1623 | while (cert_list_size--) | |
1624 | { | |
1625 | rc = import_cert(&cert_list[cert_list_size], &crt); | |
1626 | if (rc != GNUTLS_E_SUCCESS) | |
1627 | { | |
1628 | DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n", | |
1629 | cert_list_size, gnutls_strerror(rc)); | |
1630 | break; | |
1631 | } | |
1632 | ||
1633 | state->tlsp->peercert = crt; | |
b30275b8 JH |
1634 | if ((yield = event_raise(state->event_action, |
1635 | US"tls:cert", string_sprintf("%d", cert_list_size)))) | |
a7538db1 JH |
1636 | { |
1637 | log_write(0, LOG_MAIN, | |
b30275b8 JH |
1638 | "SSL verify denied by event-action: depth=%d: %s", |
1639 | cert_list_size, yield); | |
a7538db1 JH |
1640 | return 1; /* reject */ |
1641 | } | |
1642 | state->tlsp->peercert = NULL; | |
1643 | } | |
1644 | ||
1645 | return 0; | |
1646 | } | |
1647 | ||
1648 | #endif | |
44662487 JH |
1649 | |
1650 | ||
17c76198 PP |
1651 | |
1652 | /* ------------------------------------------------------------------------ */ | |
1653 | /* Exported functions */ | |
1654 | ||
1655 | ||
1656 | ||
1657 | ||
059ec3d9 PH |
1658 | /************************************************* |
1659 | * Start a TLS session in a server * | |
1660 | *************************************************/ | |
1661 | ||
1662 | /* This is called when Exim is running as a server, after having received | |
1663 | the STARTTLS command. It must respond to that command, and then negotiate | |
1664 | a TLS session. | |
1665 | ||
1666 | Arguments: | |
83da1223 | 1667 | require_ciphers list of allowed ciphers or NULL |
059ec3d9 PH |
1668 | |
1669 | Returns: OK on success | |
1670 | DEFER for errors before the start of the negotiation | |
1671 | FAIL for errors during the negotation; the server can't | |
1672 | continue running. | |
1673 | */ | |
1674 | ||
1675 | int | |
17c76198 | 1676 | tls_server_start(const uschar *require_ciphers) |
059ec3d9 PH |
1677 | { |
1678 | int rc; | |
7199e1ee | 1679 | const char *error; |
17c76198 | 1680 | exim_gnutls_state_st *state = NULL; |
059ec3d9 PH |
1681 | |
1682 | /* Check for previous activation */ | |
817d9f57 | 1683 | if (tls_in.active >= 0) |
059ec3d9 | 1684 | { |
17c76198 | 1685 | tls_error(US"STARTTLS received after TLS started", "", NULL); |
059ec3d9 PH |
1686 | smtp_printf("554 Already in TLS\r\n"); |
1687 | return FAIL; | |
1688 | } | |
1689 | ||
1690 | /* Initialize the library. If it fails, it will already have logged the error | |
1691 | and sent an SMTP response. */ | |
1692 | ||
17c76198 | 1693 | DEBUG(D_tls) debug_printf("initialising GnuTLS as a server\n"); |
059ec3d9 | 1694 | |
17c76198 PP |
1695 | rc = tls_init(NULL, tls_certificate, tls_privatekey, |
1696 | NULL, tls_verify_certificates, tls_crl, | |
1697 | require_ciphers, &state); | |
059ec3d9 PH |
1698 | if (rc != OK) return rc; |
1699 | ||
059ec3d9 PH |
1700 | /* If this is a host for which certificate verification is mandatory or |
1701 | optional, set up appropriately. */ | |
1702 | ||
059ec3d9 | 1703 | if (verify_check_host(&tls_verify_hosts) == OK) |
17c76198 | 1704 | { |
e51c7be2 JH |
1705 | DEBUG(D_tls) |
1706 | debug_printf("TLS: a client certificate will be required.\n"); | |
17c76198 PP |
1707 | state->verify_requirement = VERIFY_REQUIRED; |
1708 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); | |
1709 | } | |
059ec3d9 | 1710 | else if (verify_check_host(&tls_try_verify_hosts) == OK) |
17c76198 | 1711 | { |
e51c7be2 JH |
1712 | DEBUG(D_tls) |
1713 | debug_printf("TLS: a client certificate will be requested but not required.\n"); | |
17c76198 PP |
1714 | state->verify_requirement = VERIFY_OPTIONAL; |
1715 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST); | |
1716 | } | |
1717 | else | |
1718 | { | |
e51c7be2 JH |
1719 | DEBUG(D_tls) |
1720 | debug_printf("TLS: a client certificate will not be requested.\n"); | |
17c76198 PP |
1721 | state->verify_requirement = VERIFY_NONE; |
1722 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); | |
1723 | } | |
059ec3d9 | 1724 | |
0cbf2b82 | 1725 | #ifndef DISABLE_EVENT |
723fe533 JH |
1726 | if (event_action) |
1727 | { | |
1728 | state->event_action = event_action; | |
1729 | gnutls_session_set_ptr(state->session, state); | |
1730 | gnutls_certificate_set_verify_function(state->x509_cred, verify_cb); | |
1731 | } | |
1732 | #endif | |
1733 | ||
17c76198 PP |
1734 | /* Register SNI handling; always, even if not in tls_certificate, so that the |
1735 | expansion variable $tls_sni is always available. */ | |
059ec3d9 | 1736 | |
17c76198 PP |
1737 | gnutls_handshake_set_post_client_hello_function(state->session, |
1738 | exim_sni_handling_cb); | |
059ec3d9 PH |
1739 | |
1740 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
1741 | on connection, where outputting anything now upsets the clients and tends to | |
1742 | make them disconnect. We need to have an explicit fflush() here, to force out | |
1743 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
1744 | mode, the fflush() happens when smtp_getc() is called. */ | |
1745 | ||
817d9f57 | 1746 | if (!state->tlsp->on_connect) |
059ec3d9 PH |
1747 | { |
1748 | smtp_printf("220 TLS go ahead\r\n"); | |
9d1c15ef | 1749 | fflush(smtp_out); |
059ec3d9 PH |
1750 | } |
1751 | ||
1752 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
1753 | that the GnuTLS library doesn't. */ | |
1754 | ||
17c76198 | 1755 | gnutls_transport_set_ptr2(state->session, |
27f19eb4 JH |
1756 | (gnutls_transport_ptr_t)(long) fileno(smtp_in), |
1757 | (gnutls_transport_ptr_t)(long) fileno(smtp_out)); | |
17c76198 PP |
1758 | state->fd_in = fileno(smtp_in); |
1759 | state->fd_out = fileno(smtp_out); | |
059ec3d9 PH |
1760 | |
1761 | sigalrm_seen = FALSE; | |
1762 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
17c76198 PP |
1763 | do |
1764 | { | |
1765 | rc = gnutls_handshake(state->session); | |
619b2b25 PP |
1766 | } while ((rc == GNUTLS_E_AGAIN) || |
1767 | (rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen)); | |
059ec3d9 PH |
1768 | alarm(0); |
1769 | ||
17c76198 | 1770 | if (rc != GNUTLS_E_SUCCESS) |
059ec3d9 | 1771 | { |
17c76198 PP |
1772 | tls_error(US"gnutls_handshake", |
1773 | sigalrm_seen ? "timed out" : gnutls_strerror(rc), NULL); | |
059ec3d9 PH |
1774 | /* It seems that, except in the case of a timeout, we have to close the |
1775 | connection right here; otherwise if the other end is running OpenSSL it hangs | |
1776 | until the server times out. */ | |
1777 | ||
1778 | if (!sigalrm_seen) | |
1779 | { | |
f1e894f3 PH |
1780 | (void)fclose(smtp_out); |
1781 | (void)fclose(smtp_in); | |
059ec3d9 PH |
1782 | } |
1783 | ||
1784 | return FAIL; | |
1785 | } | |
1786 | ||
1787 | DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n"); | |
1788 | ||
17c76198 PP |
1789 | /* Verify after the fact */ |
1790 | ||
9d1c15ef JH |
1791 | if ( state->verify_requirement != VERIFY_NONE |
1792 | && !verify_certificate(state, &error)) | |
059ec3d9 | 1793 | { |
9d1c15ef | 1794 | if (state->verify_requirement != VERIFY_OPTIONAL) |
17c76198 | 1795 | { |
9d1c15ef JH |
1796 | tls_error(US"certificate verification failed", error, NULL); |
1797 | return FAIL; | |
17c76198 | 1798 | } |
9d1c15ef JH |
1799 | DEBUG(D_tls) |
1800 | debug_printf("TLS: continuing on only because verification was optional, after: %s\n", | |
1801 | error); | |
059ec3d9 PH |
1802 | } |
1803 | ||
17c76198 PP |
1804 | /* Figure out peer DN, and if authenticated, etc. */ |
1805 | ||
1806 | rc = peer_status(state); | |
1807 | if (rc != OK) return rc; | |
1808 | ||
1809 | /* Sets various Exim expansion variables; always safe within server */ | |
1810 | ||
9d1c15ef | 1811 | extract_exim_vars_from_tls_state(state); |
059ec3d9 PH |
1812 | |
1813 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
1814 | and initialize appropriately. */ | |
1815 | ||
17c76198 | 1816 | state->xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
059ec3d9 PH |
1817 | |
1818 | receive_getc = tls_getc; | |
1819 | receive_ungetc = tls_ungetc; | |
1820 | receive_feof = tls_feof; | |
1821 | receive_ferror = tls_ferror; | |
58eb016e | 1822 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 1823 | |
059ec3d9 PH |
1824 | return OK; |
1825 | } | |
1826 | ||
1827 | ||
1828 | ||
1829 | ||
aa2a70ba JH |
1830 | static void |
1831 | tls_client_setup_hostname_checks(host_item * host, exim_gnutls_state_st * state, | |
1832 | smtp_transport_options_block * ob) | |
1833 | { | |
5130845b | 1834 | if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK) |
aa2a70ba | 1835 | { |
4af0d74a | 1836 | state->exp_tls_verify_cert_hostnames = |
8c5d388a | 1837 | #ifdef SUPPORT_I18N |
4af0d74a JH |
1838 | string_domain_utf8_to_alabel(host->name, NULL); |
1839 | #else | |
1840 | host->name; | |
1841 | #endif | |
aa2a70ba JH |
1842 | DEBUG(D_tls) |
1843 | debug_printf("TLS: server cert verification includes hostname: \"%s\".\n", | |
1844 | state->exp_tls_verify_cert_hostnames); | |
1845 | } | |
1846 | } | |
aa2a70ba JH |
1847 | |
1848 | ||
059ec3d9 PH |
1849 | /************************************************* |
1850 | * Start a TLS session in a client * | |
1851 | *************************************************/ | |
1852 | ||
1853 | /* Called from the smtp transport after STARTTLS has been accepted. | |
1854 | ||
1855 | Arguments: | |
1856 | fd the fd of the connection | |
1857 | host connected host (for messages) | |
83da1223 | 1858 | addr the first address (not used) |
a7538db1 | 1859 | tb transport (always smtp) |
059ec3d9 PH |
1860 | |
1861 | Returns: OK/DEFER/FAIL (because using common functions), | |
1862 | but for a client, DEFER and FAIL have the same meaning | |
1863 | */ | |
1864 | ||
1865 | int | |
17c76198 | 1866 | tls_client_start(int fd, host_item *host, |
f5d78688 | 1867 | address_item *addr ARG_UNUSED, |
0e66b3b6 JH |
1868 | transport_instance *tb |
1869 | #ifdef EXPERIMENTAL_DANE | |
1870 | , dne_answer * unused_tlsa_dnsa | |
1871 | #endif | |
1872 | ) | |
059ec3d9 | 1873 | { |
a7538db1 JH |
1874 | smtp_transport_options_block *ob = |
1875 | (smtp_transport_options_block *)tb->options_block; | |
059ec3d9 | 1876 | int rc; |
17c76198 PP |
1877 | const char *error; |
1878 | exim_gnutls_state_st *state = NULL; | |
f2de3a33 | 1879 | #ifndef DISABLE_OCSP |
5130845b JH |
1880 | BOOL require_ocsp = |
1881 | verify_check_given_host(&ob->hosts_require_ocsp, host) == OK; | |
44662487 | 1882 | BOOL request_ocsp = require_ocsp ? TRUE |
5130845b | 1883 | : verify_check_given_host(&ob->hosts_request_ocsp, host) == OK; |
2b4a568d | 1884 | #endif |
059ec3d9 | 1885 | |
17c76198 | 1886 | DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", fd); |
059ec3d9 | 1887 | |
65867078 JH |
1888 | if ((rc = tls_init(host, ob->tls_certificate, ob->tls_privatekey, |
1889 | ob->tls_sni, ob->tls_verify_certificates, ob->tls_crl, | |
1890 | ob->tls_require_ciphers, &state)) != OK) | |
2b4a568d | 1891 | return rc; |
059ec3d9 | 1892 | |
54c90be1 | 1893 | { |
65867078 JH |
1894 | int dh_min_bits = ob->tls_dh_min_bits; |
1895 | if (dh_min_bits < EXIM_CLIENT_DH_MIN_MIN_BITS) | |
1896 | { | |
1897 | DEBUG(D_tls) | |
1898 | debug_printf("WARNING: tls_dh_min_bits far too low," | |
1899 | " clamping %d up to %d\n", | |
1900 | dh_min_bits, EXIM_CLIENT_DH_MIN_MIN_BITS); | |
1901 | dh_min_bits = EXIM_CLIENT_DH_MIN_MIN_BITS; | |
1902 | } | |
54c90be1 | 1903 | |
65867078 JH |
1904 | DEBUG(D_tls) debug_printf("Setting D-H prime minimum" |
1905 | " acceptable bits to %d\n", | |
1906 | dh_min_bits); | |
1907 | gnutls_dh_set_prime_bits(state->session, dh_min_bits); | |
1908 | } | |
83da1223 | 1909 | |
94431adb | 1910 | /* Stick to the old behaviour for compatibility if tls_verify_certificates is |
2b4a568d JH |
1911 | set but both tls_verify_hosts and tls_try_verify_hosts are unset. Check only |
1912 | the specified host patterns if one of them is defined */ | |
1913 | ||
aa2a70ba JH |
1914 | if ( ( state->exp_tls_verify_certificates |
1915 | && !ob->tls_verify_hosts | |
610ff438 | 1916 | && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) |
aa2a70ba | 1917 | ) |
5130845b | 1918 | || verify_check_given_host(&ob->tls_verify_hosts, host) == OK |
2b4a568d | 1919 | ) |
17c76198 | 1920 | { |
aa2a70ba | 1921 | tls_client_setup_hostname_checks(host, state, ob); |
aa2a70ba JH |
1922 | DEBUG(D_tls) |
1923 | debug_printf("TLS: server certificate verification required.\n"); | |
1924 | state->verify_requirement = VERIFY_REQUIRED; | |
52f93eed WB |
1925 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); |
1926 | } | |
5130845b | 1927 | else if (verify_check_given_host(&ob->tls_try_verify_hosts, host) == OK) |
52f93eed | 1928 | { |
aa2a70ba | 1929 | tls_client_setup_hostname_checks(host, state, ob); |
e51c7be2 JH |
1930 | DEBUG(D_tls) |
1931 | debug_printf("TLS: server certificate verification optional.\n"); | |
52f93eed | 1932 | state->verify_requirement = VERIFY_OPTIONAL; |
17c76198 PP |
1933 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST); |
1934 | } | |
1935 | else | |
1936 | { | |
e51c7be2 JH |
1937 | DEBUG(D_tls) |
1938 | debug_printf("TLS: server certificate verification not required.\n"); | |
52f93eed WB |
1939 | state->verify_requirement = VERIFY_NONE; |
1940 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); | |
17c76198 | 1941 | } |
059ec3d9 | 1942 | |
f2de3a33 JH |
1943 | #ifndef DISABLE_OCSP |
1944 | /* supported since GnuTLS 3.1.3 */ | |
44662487 | 1945 | if (request_ocsp) |
9d1c15ef JH |
1946 | { |
1947 | DEBUG(D_tls) debug_printf("TLS: will request OCSP stapling\n"); | |
65867078 JH |
1948 | if ((rc = gnutls_ocsp_status_request_enable_client(state->session, |
1949 | NULL, 0, NULL)) != OK) | |
9d1c15ef JH |
1950 | return tls_error(US"cert-status-req", |
1951 | gnutls_strerror(rc), state->host); | |
44662487 | 1952 | tls_out.ocsp = OCSP_NOT_RESP; |
9d1c15ef | 1953 | } |
2b4a568d JH |
1954 | #endif |
1955 | ||
0cbf2b82 | 1956 | #ifndef DISABLE_EVENT |
774ef2d7 | 1957 | if (tb->event_action) |
a7538db1 | 1958 | { |
774ef2d7 | 1959 | state->event_action = tb->event_action; |
a7538db1 | 1960 | gnutls_session_set_ptr(state->session, state); |
723fe533 | 1961 | gnutls_certificate_set_verify_function(state->x509_cred, verify_cb); |
a7538db1 JH |
1962 | } |
1963 | #endif | |
1964 | ||
27f19eb4 | 1965 | gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr_t)(long) fd); |
17c76198 PP |
1966 | state->fd_in = fd; |
1967 | state->fd_out = fd; | |
059ec3d9 | 1968 | |
9d1c15ef | 1969 | DEBUG(D_tls) debug_printf("about to gnutls_handshake\n"); |
059ec3d9 PH |
1970 | /* There doesn't seem to be a built-in timeout on connection. */ |
1971 | ||
1972 | sigalrm_seen = FALSE; | |
65867078 | 1973 | alarm(ob->command_timeout); |
17c76198 PP |
1974 | do |
1975 | { | |
1976 | rc = gnutls_handshake(state->session); | |
619b2b25 PP |
1977 | } while ((rc == GNUTLS_E_AGAIN) || |
1978 | (rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen)); | |
059ec3d9 PH |
1979 | alarm(0); |
1980 | ||
4fe99a6c PP |
1981 | if (rc != GNUTLS_E_SUCCESS) |
1982 | return tls_error(US"gnutls_handshake", | |
1983 | sigalrm_seen ? "timed out" : gnutls_strerror(rc), state->host); | |
1984 | ||
17c76198 | 1985 | DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n"); |
059ec3d9 | 1986 | |
17c76198 | 1987 | /* Verify late */ |
059ec3d9 | 1988 | |
17c76198 PP |
1989 | if (state->verify_requirement != VERIFY_NONE && |
1990 | !verify_certificate(state, &error)) | |
1991 | return tls_error(US"certificate verification failed", error, state->host); | |
059ec3d9 | 1992 | |
f2de3a33 | 1993 | #ifndef DISABLE_OCSP |
2b4a568d JH |
1994 | if (require_ocsp) |
1995 | { | |
1996 | DEBUG(D_tls) | |
1997 | { | |
1998 | gnutls_datum_t stapling; | |
1999 | gnutls_ocsp_resp_t resp; | |
2000 | gnutls_datum_t printed; | |
2001 | if ( (rc= gnutls_ocsp_status_request_get(state->session, &stapling)) == 0 | |
2002 | && (rc= gnutls_ocsp_resp_init(&resp)) == 0 | |
2003 | && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0 | |
2004 | && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_FULL, &printed)) == 0 | |
2005 | ) | |
2006 | { | |
65867078 | 2007 | debug_printf("%.4096s", printed.data); |
2b4a568d JH |
2008 | gnutls_free(printed.data); |
2009 | } | |
2010 | else | |
2011 | (void) tls_error(US"ocsp decode", gnutls_strerror(rc), state->host); | |
2012 | } | |
2013 | ||
2b4a568d | 2014 | if (gnutls_ocsp_status_request_is_checked(state->session, 0) == 0) |
018058b2 JH |
2015 | { |
2016 | tls_out.ocsp = OCSP_FAILED; | |
2b4a568d | 2017 | return tls_error(US"certificate status check failed", NULL, state->host); |
018058b2 | 2018 | } |
2b4a568d | 2019 | DEBUG(D_tls) debug_printf("Passed OCSP checking\n"); |
44662487 | 2020 | tls_out.ocsp = OCSP_VFIED; |
2b4a568d JH |
2021 | } |
2022 | #endif | |
2023 | ||
17c76198 | 2024 | /* Figure out peer DN, and if authenticated, etc. */ |
059ec3d9 | 2025 | |
2b4a568d JH |
2026 | if ((rc = peer_status(state)) != OK) |
2027 | return rc; | |
059ec3d9 | 2028 | |
4fe99a6c | 2029 | /* Sets various Exim expansion variables; may need to adjust for ACL callouts */ |
059ec3d9 | 2030 | |
9d1c15ef | 2031 | extract_exim_vars_from_tls_state(state); |
059ec3d9 | 2032 | |
059ec3d9 PH |
2033 | return OK; |
2034 | } | |
2035 | ||
2036 | ||
2037 | ||
17c76198 | 2038 | |
059ec3d9 | 2039 | /************************************************* |
17c76198 | 2040 | * Close down a TLS session * |
059ec3d9 PH |
2041 | *************************************************/ |
2042 | ||
17c76198 PP |
2043 | /* This is also called from within a delivery subprocess forked from the |
2044 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
2045 | would tamper with the TLS session in the parent process). | |
059ec3d9 | 2046 | |
17c76198 PP |
2047 | Arguments: TRUE if gnutls_bye is to be called |
2048 | Returns: nothing | |
059ec3d9 PH |
2049 | */ |
2050 | ||
17c76198 | 2051 | void |
817d9f57 | 2052 | tls_close(BOOL is_server, BOOL shutdown) |
059ec3d9 | 2053 | { |
817d9f57 | 2054 | exim_gnutls_state_st *state = is_server ? &state_server : &state_client; |
059ec3d9 | 2055 | |
389ca47a | 2056 | if (!state->tlsp || state->tlsp->active < 0) return; /* TLS was not active */ |
17c76198 PP |
2057 | |
2058 | if (shutdown) | |
2059 | { | |
2060 | DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS\n"); | |
2061 | gnutls_bye(state->session, GNUTLS_SHUT_WR); | |
2062 | } | |
2063 | ||
2064 | gnutls_deinit(state->session); | |
2065 | ||
389ca47a | 2066 | state->tlsp->active = -1; |
17c76198 PP |
2067 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); |
2068 | ||
2069 | if ((state_server.session == NULL) && (state_client.session == NULL)) | |
2070 | { | |
2071 | gnutls_global_deinit(); | |
2072 | exim_gnutls_base_init_done = FALSE; | |
2073 | } | |
7199e1ee | 2074 | |
059ec3d9 PH |
2075 | } |
2076 | ||
2077 | ||
2078 | ||
17c76198 | 2079 | |
059ec3d9 PH |
2080 | /************************************************* |
2081 | * TLS version of getc * | |
2082 | *************************************************/ | |
2083 | ||
2084 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
2085 | it refills the buffer via the GnuTLS reading function. | |
817d9f57 | 2086 | Only used by the server-side TLS. |
059ec3d9 | 2087 | |
17c76198 PP |
2088 | This feeds DKIM and should be used for all message-body reads. |
2089 | ||
059ec3d9 PH |
2090 | Arguments: none |
2091 | Returns: the next character or EOF | |
2092 | */ | |
2093 | ||
2094 | int | |
2095 | tls_getc(void) | |
2096 | { | |
817d9f57 | 2097 | exim_gnutls_state_st *state = &state_server; |
17c76198 | 2098 | if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) |
059ec3d9 | 2099 | { |
17c76198 | 2100 | ssize_t inbytes; |
059ec3d9 | 2101 | |
17c76198 PP |
2102 | DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(%p, %p, %u)\n", |
2103 | state->session, state->xfer_buffer, ssl_xfer_buffer_size); | |
059ec3d9 PH |
2104 | |
2105 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
17c76198 | 2106 | inbytes = gnutls_record_recv(state->session, state->xfer_buffer, |
059ec3d9 PH |
2107 | ssl_xfer_buffer_size); |
2108 | alarm(0); | |
2109 | ||
2110 | /* A zero-byte return appears to mean that the TLS session has been | |
2111 | closed down, not that the socket itself has been closed down. Revert to | |
2112 | non-TLS handling. */ | |
2113 | ||
2114 | if (inbytes == 0) | |
2115 | { | |
2116 | DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); | |
2117 | ||
2118 | receive_getc = smtp_getc; | |
2119 | receive_ungetc = smtp_ungetc; | |
2120 | receive_feof = smtp_feof; | |
2121 | receive_ferror = smtp_ferror; | |
58eb016e | 2122 | receive_smtp_buffered = smtp_buffered; |
059ec3d9 | 2123 | |
17c76198 PP |
2124 | gnutls_deinit(state->session); |
2125 | state->session = NULL; | |
817d9f57 JH |
2126 | state->tlsp->active = -1; |
2127 | state->tlsp->bits = 0; | |
2128 | state->tlsp->certificate_verified = FALSE; | |
9d1c15ef | 2129 | tls_channelbinding_b64 = NULL; |
817d9f57 | 2130 | state->tlsp->cipher = NULL; |
9d1c15ef | 2131 | state->tlsp->peercert = NULL; |
817d9f57 | 2132 | state->tlsp->peerdn = NULL; |
059ec3d9 PH |
2133 | |
2134 | return smtp_getc(); | |
2135 | } | |
2136 | ||
2137 | /* Handle genuine errors */ | |
2138 | ||
2139 | else if (inbytes < 0) | |
2140 | { | |
17c76198 PP |
2141 | record_io_error(state, (int) inbytes, US"recv", NULL); |
2142 | state->xfer_error = 1; | |
059ec3d9 PH |
2143 | return EOF; |
2144 | } | |
80a47a2c | 2145 | #ifndef DISABLE_DKIM |
17c76198 | 2146 | dkim_exim_verify_feed(state->xfer_buffer, inbytes); |
80a47a2c | 2147 | #endif |
17c76198 PP |
2148 | state->xfer_buffer_hwm = (int) inbytes; |
2149 | state->xfer_buffer_lwm = 0; | |
059ec3d9 PH |
2150 | } |
2151 | ||
059ec3d9 PH |
2152 | /* Something in the buffer; return next uschar */ |
2153 | ||
17c76198 | 2154 | return state->xfer_buffer[state->xfer_buffer_lwm++]; |
059ec3d9 PH |
2155 | } |
2156 | ||
2157 | ||
2158 | ||
17c76198 | 2159 | |
059ec3d9 PH |
2160 | /************************************************* |
2161 | * Read bytes from TLS channel * | |
2162 | *************************************************/ | |
2163 | ||
17c76198 PP |
2164 | /* This does not feed DKIM, so if the caller uses this for reading message body, |
2165 | then the caller must feed DKIM. | |
817d9f57 | 2166 | |
059ec3d9 PH |
2167 | Arguments: |
2168 | buff buffer of data | |
2169 | len size of buffer | |
2170 | ||
2171 | Returns: the number of bytes read | |
2172 | -1 after a failed read | |
2173 | */ | |
2174 | ||
2175 | int | |
817d9f57 | 2176 | tls_read(BOOL is_server, uschar *buff, size_t len) |
059ec3d9 | 2177 | { |
817d9f57 | 2178 | exim_gnutls_state_st *state = is_server ? &state_server : &state_client; |
17c76198 | 2179 | ssize_t inbytes; |
059ec3d9 | 2180 | |
17c76198 PP |
2181 | if (len > INT_MAX) |
2182 | len = INT_MAX; | |
059ec3d9 | 2183 | |
17c76198 PP |
2184 | if (state->xfer_buffer_lwm < state->xfer_buffer_hwm) |
2185 | DEBUG(D_tls) | |
2186 | debug_printf("*** PROBABLY A BUG *** " \ | |
2187 | "tls_read() called with data in the tls_getc() buffer, %d ignored\n", | |
2188 | state->xfer_buffer_hwm - state->xfer_buffer_lwm); | |
2189 | ||
2190 | DEBUG(D_tls) | |
2191 | debug_printf("Calling gnutls_record_recv(%p, %p, " SIZE_T_FMT ")\n", | |
2192 | state->session, buff, len); | |
2193 | ||
2194 | inbytes = gnutls_record_recv(state->session, buff, len); | |
059ec3d9 PH |
2195 | if (inbytes > 0) return inbytes; |
2196 | if (inbytes == 0) | |
2197 | { | |
2198 | DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); | |
2199 | } | |
17c76198 | 2200 | else record_io_error(state, (int)inbytes, US"recv", NULL); |
059ec3d9 PH |
2201 | |
2202 | return -1; | |
2203 | } | |
2204 | ||
2205 | ||
2206 | ||
17c76198 | 2207 | |
059ec3d9 PH |
2208 | /************************************************* |
2209 | * Write bytes down TLS channel * | |
2210 | *************************************************/ | |
2211 | ||
2212 | /* | |
2213 | Arguments: | |
817d9f57 | 2214 | is_server channel specifier |
059ec3d9 PH |
2215 | buff buffer of data |
2216 | len number of bytes | |
2217 | ||
2218 | Returns: the number of bytes after a successful write, | |
2219 | -1 after a failed write | |
2220 | */ | |
2221 | ||
2222 | int | |
817d9f57 | 2223 | tls_write(BOOL is_server, const uschar *buff, size_t len) |
059ec3d9 | 2224 | { |
17c76198 PP |
2225 | ssize_t outbytes; |
2226 | size_t left = len; | |
817d9f57 | 2227 | exim_gnutls_state_st *state = is_server ? &state_server : &state_client; |
059ec3d9 | 2228 | |
17c76198 | 2229 | DEBUG(D_tls) debug_printf("tls_do_write(%p, " SIZE_T_FMT ")\n", buff, left); |
059ec3d9 PH |
2230 | while (left > 0) |
2231 | { | |
17c76198 PP |
2232 | DEBUG(D_tls) debug_printf("gnutls_record_send(SSL, %p, " SIZE_T_FMT ")\n", |
2233 | buff, left); | |
2234 | outbytes = gnutls_record_send(state->session, buff, left); | |
059ec3d9 | 2235 | |
17c76198 | 2236 | DEBUG(D_tls) debug_printf("outbytes=" SSIZE_T_FMT "\n", outbytes); |
059ec3d9 PH |
2237 | if (outbytes < 0) |
2238 | { | |
17c76198 | 2239 | record_io_error(state, outbytes, US"send", NULL); |
059ec3d9 PH |
2240 | return -1; |
2241 | } | |
2242 | if (outbytes == 0) | |
2243 | { | |
17c76198 | 2244 | record_io_error(state, 0, US"send", US"TLS channel closed on write"); |
059ec3d9 PH |
2245 | return -1; |
2246 | } | |
2247 | ||
2248 | left -= outbytes; | |
2249 | buff += outbytes; | |
2250 | } | |
2251 | ||
17c76198 PP |
2252 | if (len > INT_MAX) |
2253 | { | |
2254 | DEBUG(D_tls) | |
2255 | debug_printf("Whoops! Wrote more bytes (" SIZE_T_FMT ") than INT_MAX\n", | |
2256 | len); | |
2257 | len = INT_MAX; | |
2258 | } | |
2259 | ||
2260 | return (int) len; | |
059ec3d9 PH |
2261 | } |
2262 | ||
2263 | ||
2264 | ||
17c76198 | 2265 | |
059ec3d9 | 2266 | /************************************************* |
17c76198 | 2267 | * Random number generation * |
059ec3d9 PH |
2268 | *************************************************/ |
2269 | ||
17c76198 PP |
2270 | /* Pseudo-random number generation. The result is not expected to be |
2271 | cryptographically strong but not so weak that someone will shoot themselves | |
2272 | in the foot using it as a nonce in input in some email header scheme or | |
2273 | whatever weirdness they'll twist this into. The result should handle fork() | |
2274 | and avoid repeating sequences. OpenSSL handles that for us. | |
059ec3d9 | 2275 | |
17c76198 PP |
2276 | Arguments: |
2277 | max range maximum | |
2278 | Returns a random number in range [0, max-1] | |
059ec3d9 PH |
2279 | */ |
2280 | ||
af3498d6 | 2281 | #ifdef HAVE_GNUTLS_RND |
17c76198 PP |
2282 | int |
2283 | vaguely_random_number(int max) | |
059ec3d9 | 2284 | { |
17c76198 PP |
2285 | unsigned int r; |
2286 | int i, needed_len; | |
2287 | uschar *p; | |
2288 | uschar smallbuf[sizeof(r)]; | |
2289 | ||
2290 | if (max <= 1) | |
2291 | return 0; | |
2292 | ||
2293 | needed_len = sizeof(r); | |
2294 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
2295 | * asked for a number less than 10. */ | |
2296 | for (r = max, i = 0; r; ++i) | |
2297 | r >>= 1; | |
2298 | i = (i + 7) / 8; | |
2299 | if (i < needed_len) | |
2300 | needed_len = i; | |
2301 | ||
2302 | i = gnutls_rnd(GNUTLS_RND_NONCE, smallbuf, needed_len); | |
2303 | if (i < 0) | |
059ec3d9 | 2304 | { |
17c76198 PP |
2305 | DEBUG(D_all) debug_printf("gnutls_rnd() failed, using fallback.\n"); |
2306 | return vaguely_random_number_fallback(max); | |
2307 | } | |
2308 | r = 0; | |
2309 | for (p = smallbuf; needed_len; --needed_len, ++p) | |
2310 | { | |
2311 | r *= 256; | |
2312 | r += *p; | |
059ec3d9 PH |
2313 | } |
2314 | ||
17c76198 PP |
2315 | /* We don't particularly care about weighted results; if someone wants |
2316 | * smooth distribution and cares enough then they should submit a patch then. */ | |
2317 | return r % max; | |
059ec3d9 | 2318 | } |
af3498d6 PP |
2319 | #else /* HAVE_GNUTLS_RND */ |
2320 | int | |
2321 | vaguely_random_number(int max) | |
2322 | { | |
2323 | return vaguely_random_number_fallback(max); | |
2324 | } | |
2325 | #endif /* HAVE_GNUTLS_RND */ | |
059ec3d9 | 2326 | |
36f12725 NM |
2327 | |
2328 | ||
2329 | ||
3375e053 PP |
2330 | /************************************************* |
2331 | * Let tls_require_ciphers be checked at startup * | |
2332 | *************************************************/ | |
2333 | ||
2334 | /* The tls_require_ciphers option, if set, must be something which the | |
2335 | library can parse. | |
2336 | ||
2337 | Returns: NULL on success, or error message | |
2338 | */ | |
2339 | ||
2340 | uschar * | |
2341 | tls_validate_require_cipher(void) | |
2342 | { | |
2343 | int rc; | |
2344 | uschar *expciphers = NULL; | |
2345 | gnutls_priority_t priority_cache; | |
2346 | const char *errpos; | |
2347 | ||
2348 | #define validate_check_rc(Label) do { \ | |
2349 | if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) gnutls_global_deinit(); \ | |
2350 | return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0) | |
2351 | #define return_deinit(Label) do { gnutls_global_deinit(); return (Label); } while (0) | |
2352 | ||
2353 | if (exim_gnutls_base_init_done) | |
2354 | log_write(0, LOG_MAIN|LOG_PANIC, | |
2355 | "already initialised GnuTLS, Exim developer bug"); | |
2356 | ||
a5f239e4 | 2357 | #ifdef HAVE_GNUTLS_PKCS11 |
2519e60d | 2358 | if (!gnutls_allow_auto_pkcs11) |
a5f239e4 PP |
2359 | { |
2360 | rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL); | |
2361 | validate_check_rc(US"gnutls_pkcs11_init"); | |
2362 | } | |
2363 | #endif | |
3375e053 PP |
2364 | rc = gnutls_global_init(); |
2365 | validate_check_rc(US"gnutls_global_init()"); | |
2366 | exim_gnutls_base_init_done = TRUE; | |
2367 | ||
2368 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
2369 | return_deinit(NULL); | |
2370 | ||
2371 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers)) | |
2372 | return_deinit(US"failed to expand tls_require_ciphers"); | |
2373 | ||
2374 | if (!(expciphers && *expciphers)) | |
2375 | return_deinit(NULL); | |
2376 | ||
2377 | DEBUG(D_tls) | |
2378 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
2379 | ||
2380 | rc = gnutls_priority_init(&priority_cache, CS expciphers, &errpos); | |
2381 | validate_check_rc(string_sprintf( | |
2382 | "gnutls_priority_init(%s) failed at offset %ld, \"%.8s..\"", | |
2383 | expciphers, errpos - CS expciphers, errpos)); | |
2384 | ||
2385 | #undef return_deinit | |
2386 | #undef validate_check_rc | |
2387 | gnutls_global_deinit(); | |
2388 | ||
2389 | return NULL; | |
2390 | } | |
2391 | ||
2392 | ||
2393 | ||
2394 | ||
36f12725 NM |
2395 | /************************************************* |
2396 | * Report the library versions. * | |
2397 | *************************************************/ | |
2398 | ||
2399 | /* See a description in tls-openssl.c for an explanation of why this exists. | |
2400 | ||
2401 | Arguments: a FILE* to print the results to | |
2402 | Returns: nothing | |
2403 | */ | |
2404 | ||
2405 | void | |
2406 | tls_version_report(FILE *f) | |
2407 | { | |
754a0503 PP |
2408 | fprintf(f, "Library version: GnuTLS: Compile: %s\n" |
2409 | " Runtime: %s\n", | |
2410 | LIBGNUTLS_VERSION, | |
2411 | gnutls_check_version(NULL)); | |
36f12725 NM |
2412 | } |
2413 | ||
2b4a568d JH |
2414 | /* vi: aw ai sw=2 |
2415 | */ | |
059ec3d9 | 2416 | /* End of tls-gnu.c */ |