Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
f9ba5e22 | 5 | /* Copyright (c) University of Cambridge 1995 - 2018 */ |
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 | |
6aa6fc9c | 16 | Mavrogiannopoulos. The revamp is partially a rewrite, partially cut&paste as |
17c76198 | 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> | |
184384c3 | 42 | |
a5f239e4 PP |
43 | /* needed to disable PKCS11 autoload unless requested */ |
44 | #if GNUTLS_VERSION_NUMBER >= 0x020c00 | |
45 | # include <gnutls/pkcs11.h> | |
76075bb5 | 46 | # define SUPPORT_PARAM_TO_PK_BITS |
a5f239e4 | 47 | #endif |
7e07527a JH |
48 | #if GNUTLS_VERSION_NUMBER < 0x030103 && !defined(DISABLE_OCSP) |
49 | # warning "GnuTLS library version too old; define DISABLE_OCSP in Makefile" | |
50 | # define DISABLE_OCSP | |
51 | #endif | |
0cbf2b82 | 52 | #if GNUTLS_VERSION_NUMBER < 0x020a00 && !defined(DISABLE_EVENT) |
774ef2d7 | 53 | # warning "GnuTLS library version too old; tls:cert event unsupported" |
0cbf2b82 | 54 | # define DISABLE_EVENT |
a7538db1 | 55 | #endif |
a7fec7a7 JH |
56 | #if GNUTLS_VERSION_NUMBER >= 0x030306 |
57 | # define SUPPORT_CA_DIR | |
58 | #else | |
59 | # undef SUPPORT_CA_DIR | |
60 | #endif | |
11a04b5a | 61 | #if GNUTLS_VERSION_NUMBER >= 0x030014 |
cb1d7830 JH |
62 | # define SUPPORT_SYSDEFAULT_CABUNDLE |
63 | #endif | |
184384c3 JH |
64 | #if GNUTLS_VERSION_NUMBER >= 0x030104 |
65 | # define GNUTLS_CERT_VFY_STATUS_PRINT | |
66 | #endif | |
925ac8e4 JH |
67 | #if GNUTLS_VERSION_NUMBER >= 0x030109 |
68 | # define SUPPORT_CORK | |
69 | #endif | |
f20cfa4a JH |
70 | #if GNUTLS_VERSION_NUMBER >= 0x03010a |
71 | # define SUPPORT_GNUTLS_SESS_DESC | |
72 | #endif | |
73 | #if GNUTLS_VERSION_NUMBER >= 0x030500 | |
74 | # define SUPPORT_GNUTLS_KEYLOG | |
75 | #endif | |
47195144 JH |
76 | #if GNUTLS_VERSION_NUMBER >= 0x030506 && !defined(DISABLE_OCSP) |
77 | # define SUPPORT_SRV_OCSP_STACK | |
78 | #endif | |
c0635b6d JH |
79 | |
80 | #ifdef SUPPORT_DANE | |
81 | # if GNUTLS_VERSION_NUMBER >= 0x030000 | |
82 | # define DANESSL_USAGE_DANE_TA 2 | |
83 | # define DANESSL_USAGE_DANE_EE 3 | |
84 | # else | |
85 | # error GnuTLS version too early for DANE | |
86 | # endif | |
87 | # if GNUTLS_VERSION_NUMBER < 0x999999 | |
88 | # define GNUTLS_BROKEN_DANE_VALIDATION | |
89 | # endif | |
899b8bbc | 90 | #endif |
7e07527a | 91 | |
f2de3a33 | 92 | #ifndef DISABLE_OCSP |
2b4a568d JH |
93 | # include <gnutls/ocsp.h> |
94 | #endif | |
899b8bbc JH |
95 | #ifdef SUPPORT_DANE |
96 | # include <gnutls/dane.h> | |
97 | #endif | |
059ec3d9 | 98 | |
17c76198 | 99 | /* GnuTLS 2 vs 3 |
059ec3d9 | 100 | |
17c76198 PP |
101 | GnuTLS 3 only: |
102 | gnutls_global_set_audit_log_function() | |
059ec3d9 | 103 | |
17c76198 PP |
104 | Changes: |
105 | gnutls_certificate_verify_peers2(): is new, drop the 2 for old version | |
106 | */ | |
059ec3d9 | 107 | |
17c76198 | 108 | /* Local static variables for GnuTLS */ |
059ec3d9 | 109 | |
17c76198 | 110 | /* Values for verify_requirement */ |
059ec3d9 | 111 | |
e51c7be2 | 112 | enum peer_verify_requirement |
899b8bbc | 113 | { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED, VERIFY_DANE }; |
059ec3d9 | 114 | |
17c76198 PP |
115 | /* This holds most state for server or client; with this, we can set up an |
116 | outbound TLS-enabled connection in an ACL callout, while not stomping all | |
117 | over the TLS variables available for expansion. | |
059ec3d9 | 118 | |
17c76198 PP |
119 | Some of these correspond to variables in globals.c; those variables will |
120 | be set to point to content in one of these instances, as appropriate for | |
121 | the stage of the process lifetime. | |
059ec3d9 | 122 | |
389ca47a | 123 | Not handled here: global tls_channelbinding_b64. |
17c76198 | 124 | */ |
059ec3d9 | 125 | |
17c76198 | 126 | typedef struct exim_gnutls_state { |
9d1c15ef | 127 | gnutls_session_t session; |
17c76198 | 128 | gnutls_certificate_credentials_t x509_cred; |
9d1c15ef | 129 | gnutls_priority_t priority_cache; |
17c76198 | 130 | enum peer_verify_requirement verify_requirement; |
9d1c15ef JH |
131 | int fd_in; |
132 | int fd_out; | |
133 | BOOL peer_cert_verified; | |
899b8bbc | 134 | BOOL peer_dane_verified; |
9d1c15ef JH |
135 | BOOL trigger_sni_changes; |
136 | BOOL have_set_peerdn; | |
5fd28bb8 | 137 | const struct host_item *host; /* NULL if server */ |
afdb5e9c | 138 | gnutls_x509_crt_t peercert; |
9d1c15ef JH |
139 | uschar *peerdn; |
140 | uschar *ciphersuite; | |
141 | uschar *received_sni; | |
17c76198 PP |
142 | |
143 | const uschar *tls_certificate; | |
144 | const uschar *tls_privatekey; | |
145 | const uschar *tls_sni; /* client send only, not received */ | |
146 | const uschar *tls_verify_certificates; | |
147 | const uschar *tls_crl; | |
148 | const uschar *tls_require_ciphers; | |
e51c7be2 | 149 | |
17c76198 PP |
150 | uschar *exp_tls_certificate; |
151 | uschar *exp_tls_privatekey; | |
17c76198 PP |
152 | uschar *exp_tls_verify_certificates; |
153 | uschar *exp_tls_crl; | |
154 | uschar *exp_tls_require_ciphers; | |
55414b25 | 155 | const uschar *exp_tls_verify_cert_hostnames; |
0cbf2b82 | 156 | #ifndef DISABLE_EVENT |
a7538db1 JH |
157 | uschar *event_action; |
158 | #endif | |
899b8bbc JH |
159 | #ifdef SUPPORT_DANE |
160 | char * const * dane_data; | |
161 | const int * dane_data_len; | |
162 | #endif | |
17c76198 | 163 | |
389ca47a | 164 | tls_support *tlsp; /* set in tls_init() */ |
817d9f57 | 165 | |
17c76198 PP |
166 | uschar *xfer_buffer; |
167 | int xfer_buffer_lwm; | |
168 | int xfer_buffer_hwm; | |
8b77d27a JH |
169 | BOOL xfer_eof; /*XXX never gets set! */ |
170 | BOOL xfer_error; | |
17c76198 PP |
171 | } exim_gnutls_state_st; |
172 | ||
173 | static const exim_gnutls_state_st exim_gnutls_state_init = { | |
f2ed27cf JH |
174 | .session = NULL, |
175 | .x509_cred = NULL, | |
176 | .priority_cache = NULL, | |
177 | .verify_requirement = VERIFY_NONE, | |
178 | .fd_in = -1, | |
179 | .fd_out = -1, | |
180 | .peer_cert_verified = FALSE, | |
899b8bbc | 181 | .peer_dane_verified = FALSE, |
f2ed27cf JH |
182 | .trigger_sni_changes =FALSE, |
183 | .have_set_peerdn = FALSE, | |
184 | .host = NULL, | |
185 | .peercert = NULL, | |
186 | .peerdn = NULL, | |
187 | .ciphersuite = NULL, | |
188 | .received_sni = NULL, | |
189 | ||
190 | .tls_certificate = NULL, | |
191 | .tls_privatekey = NULL, | |
192 | .tls_sni = NULL, | |
193 | .tls_verify_certificates = NULL, | |
194 | .tls_crl = NULL, | |
195 | .tls_require_ciphers =NULL, | |
196 | ||
197 | .exp_tls_certificate = NULL, | |
198 | .exp_tls_privatekey = NULL, | |
199 | .exp_tls_verify_certificates = NULL, | |
200 | .exp_tls_crl = NULL, | |
201 | .exp_tls_require_ciphers = NULL, | |
f2ed27cf | 202 | .exp_tls_verify_cert_hostnames = NULL, |
0cbf2b82 | 203 | #ifndef DISABLE_EVENT |
f2ed27cf | 204 | .event_action = NULL, |
e51c7be2 | 205 | #endif |
f2ed27cf JH |
206 | .tlsp = NULL, |
207 | ||
208 | .xfer_buffer = NULL, | |
209 | .xfer_buffer_lwm = 0, | |
210 | .xfer_buffer_hwm = 0, | |
8b77d27a JH |
211 | .xfer_eof = FALSE, |
212 | .xfer_error = FALSE, | |
17c76198 | 213 | }; |
83da1223 | 214 | |
17c76198 PP |
215 | /* Not only do we have our own APIs which don't pass around state, assuming |
216 | it's held in globals, GnuTLS doesn't appear to let us register callback data | |
217 | for callbacks, or as part of the session, so we have to keep a "this is the | |
218 | context we're currently dealing with" pointer and rely upon being | |
219 | single-threaded to keep from processing data on an inbound TLS connection while | |
220 | talking to another TLS connection for an outbound check. This does mean that | |
221 | there's no way for heart-beats to be responded to, for the duration of the | |
a7538db1 JH |
222 | second connection. |
223 | XXX But see gnutls_session_get_ptr() | |
224 | */ | |
059ec3d9 | 225 | |
74f1a423 | 226 | static exim_gnutls_state_st state_server; |
059ec3d9 | 227 | |
17c76198 PP |
228 | /* dh_params are initialised once within the lifetime of a process using TLS; |
229 | if we used TLS in a long-lived daemon, we'd have to reconsider this. But we | |
230 | don't want to repeat this. */ | |
83da1223 | 231 | |
17c76198 | 232 | static gnutls_dh_params_t dh_server_params = NULL; |
059ec3d9 | 233 | |
17c76198 | 234 | /* No idea how this value was chosen; preserving it. Default is 3600. */ |
059ec3d9 | 235 | |
17c76198 | 236 | static const int ssl_session_timeout = 200; |
059ec3d9 | 237 | |
17c76198 | 238 | static const char * const exim_default_gnutls_priority = "NORMAL"; |
83da1223 | 239 | |
17c76198 | 240 | /* Guard library core initialisation */ |
83da1223 | 241 | |
17c76198 | 242 | static BOOL exim_gnutls_base_init_done = FALSE; |
059ec3d9 | 243 | |
4fb7df6d | 244 | #ifndef DISABLE_OCSP |
9196d5bf | 245 | static BOOL gnutls_buggy_ocsp = FALSE; |
4fb7df6d | 246 | #endif |
9196d5bf | 247 | |
059ec3d9 | 248 | |
17c76198 PP |
249 | /* ------------------------------------------------------------------------ */ |
250 | /* macros */ | |
83da1223 | 251 | |
17c76198 | 252 | #define MAX_HOST_LEN 255 |
83da1223 | 253 | |
17c76198 PP |
254 | /* Set this to control gnutls_global_set_log_level(); values 0 to 9 will setup |
255 | the library logging; a value less than 0 disables the calls to set up logging | |
ef9da2ee JH |
256 | callbacks. Possibly GNuTLS also looks for an environment variable |
257 | "GNUTLS_DEBUG_LEVEL". */ | |
2c17bb02 | 258 | #ifndef EXIM_GNUTLS_LIBRARY_LOG_LEVEL |
a7538db1 | 259 | # define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1 |
2c17bb02 | 260 | #endif |
83da1223 | 261 | |
2c17bb02 | 262 | #ifndef EXIM_CLIENT_DH_MIN_BITS |
a7538db1 | 263 | # define EXIM_CLIENT_DH_MIN_BITS 1024 |
2c17bb02 | 264 | #endif |
83da1223 | 265 | |
af3498d6 PP |
266 | /* With GnuTLS 2.12.x+ we have gnutls_sec_param_to_pk_bits() with which we |
267 | can ask for a bit-strength. Without that, we stick to the constant we had | |
268 | before, for now. */ | |
2c17bb02 | 269 | #ifndef EXIM_SERVER_DH_BITS_PRE2_12 |
a7538db1 | 270 | # define EXIM_SERVER_DH_BITS_PRE2_12 1024 |
2c17bb02 | 271 | #endif |
af3498d6 | 272 | |
47195144 JH |
273 | #define exim_gnutls_err_check(rc, Label) do { \ |
274 | if ((rc) != GNUTLS_E_SUCCESS) \ | |
48224640 | 275 | return tls_error((Label), US gnutls_strerror(rc), host, errstr); \ |
cf0c6164 | 276 | } while (0) |
059ec3d9 | 277 | |
cf0c6164 JH |
278 | #define expand_check_tlsvar(Varname, errstr) \ |
279 | expand_check(state->Varname, US #Varname, &state->exp_##Varname, errstr) | |
83da1223 | 280 | |
17c76198 | 281 | #if GNUTLS_VERSION_NUMBER >= 0x020c00 |
e51c7be2 JH |
282 | # define HAVE_GNUTLS_SESSION_CHANNEL_BINDING |
283 | # define HAVE_GNUTLS_SEC_PARAM_CONSTANTS | |
284 | # define HAVE_GNUTLS_RND | |
2519e60d TL |
285 | /* The security fix we provide with the gnutls_allow_auto_pkcs11 option |
286 | * (4.82 PP/09) introduces a compatibility regression. The symbol simply | |
287 | * isn't available sometimes, so this needs to become a conditional | |
288 | * compilation; the sanest way to deal with this being a problem on | |
289 | * older OSes is to block it in the Local/Makefile with this compiler | |
290 | * definition */ | |
e51c7be2 JH |
291 | # ifndef AVOID_GNUTLS_PKCS11 |
292 | # define HAVE_GNUTLS_PKCS11 | |
293 | # endif /* AVOID_GNUTLS_PKCS11 */ | |
17c76198 | 294 | #endif |
83da1223 | 295 | |
af3498d6 PP |
296 | |
297 | ||
298 | ||
299 | /* ------------------------------------------------------------------------ */ | |
300 | /* Callback declarations */ | |
301 | ||
302 | #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 | |
303 | static void exim_gnutls_logger_cb(int level, const char *message); | |
304 | #endif | |
305 | ||
306 | static int exim_sni_handling_cb(gnutls_session_t session); | |
307 | ||
f2de3a33 | 308 | #ifndef DISABLE_OCSP |
44662487 JH |
309 | static int server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, |
310 | gnutls_datum_t * ocsp_response); | |
311 | #endif | |
af3498d6 PP |
312 | |
313 | ||
314 | ||
17c76198 PP |
315 | /* ------------------------------------------------------------------------ */ |
316 | /* Static functions */ | |
059ec3d9 PH |
317 | |
318 | /************************************************* | |
319 | * Handle TLS error * | |
320 | *************************************************/ | |
321 | ||
322 | /* Called from lots of places when errors occur before actually starting to do | |
323 | the TLS handshake, that is, while the session is still in clear. Always returns | |
324 | DEFER for a server and FAIL for a client so that most calls can use "return | |
325 | tls_error(...)" to do this processing and then give an appropriate return. A | |
326 | single function is used for both server and client, because it is called from | |
327 | some shared functions. | |
328 | ||
329 | Argument: | |
330 | prefix text to include in the logged error | |
7199e1ee TF |
331 | msg additional error string (may be NULL) |
332 | usually obtained from gnutls_strerror() | |
17c76198 PP |
333 | host NULL if setting up a server; |
334 | the connected host if setting up a client | |
cf0c6164 | 335 | errstr pointer to returned error string |
059ec3d9 PH |
336 | |
337 | Returns: OK/DEFER/FAIL | |
338 | */ | |
339 | ||
340 | static int | |
48224640 | 341 | tls_error(const uschar *prefix, const uschar *msg, const host_item *host, |
cf0c6164 | 342 | uschar ** errstr) |
059ec3d9 | 343 | { |
cf0c6164 | 344 | if (errstr) |
48224640 | 345 | *errstr = string_sprintf("(%s)%s%s", prefix, msg ? ": " : "", msg ? msg : US""); |
cf0c6164 | 346 | return host ? FAIL : DEFER; |
059ec3d9 PH |
347 | } |
348 | ||
349 | ||
350 | ||
17c76198 | 351 | |
059ec3d9 | 352 | /************************************************* |
17c76198 | 353 | * Deal with logging errors during I/O * |
059ec3d9 PH |
354 | *************************************************/ |
355 | ||
17c76198 | 356 | /* We have to get the identity of the peer from saved data. |
059ec3d9 | 357 | |
17c76198 PP |
358 | Argument: |
359 | state the current GnuTLS exim state container | |
360 | rc the GnuTLS error code, or 0 if it's a local error | |
361 | when text identifying read or write | |
362 | text local error text when ec is 0 | |
059ec3d9 | 363 | |
17c76198 | 364 | Returns: nothing |
059ec3d9 PH |
365 | */ |
366 | ||
17c76198 PP |
367 | static void |
368 | record_io_error(exim_gnutls_state_st *state, int rc, uschar *when, uschar *text) | |
059ec3d9 | 369 | { |
48224640 | 370 | const uschar * msg; |
cf0c6164 | 371 | uschar * errstr; |
059ec3d9 | 372 | |
17c76198 | 373 | if (rc == GNUTLS_E_FATAL_ALERT_RECEIVED) |
48224640 | 374 | msg = string_sprintf("%s: %s", US gnutls_strerror(rc), |
17c76198 PP |
375 | US gnutls_alert_get_name(gnutls_alert_get(state->session))); |
376 | else | |
48224640 | 377 | msg = US gnutls_strerror(rc); |
059ec3d9 | 378 | |
cf0c6164 JH |
379 | (void) tls_error(when, msg, state->host, &errstr); |
380 | ||
381 | if (state->host) | |
382 | log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection %s", | |
383 | state->host->name, state->host->address, errstr); | |
384 | else | |
385 | { | |
386 | uschar * conn_info = smtp_get_connection_info(); | |
387 | if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5; | |
388 | /* I'd like to get separated H= here, but too hard for now */ | |
389 | log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr); | |
390 | } | |
17c76198 | 391 | } |
059ec3d9 | 392 | |
059ec3d9 | 393 | |
059ec3d9 | 394 | |
059ec3d9 | 395 | |
17c76198 PP |
396 | /************************************************* |
397 | * Set various Exim expansion vars * | |
398 | *************************************************/ | |
059ec3d9 | 399 | |
e51c7be2 JH |
400 | #define exim_gnutls_cert_err(Label) \ |
401 | do \ | |
402 | { \ | |
403 | if (rc != GNUTLS_E_SUCCESS) \ | |
404 | { \ | |
405 | DEBUG(D_tls) debug_printf("TLS: cert problem: %s: %s\n", \ | |
406 | (Label), gnutls_strerror(rc)); \ | |
407 | return rc; \ | |
408 | } \ | |
409 | } while (0) | |
9d1c15ef JH |
410 | |
411 | static int | |
27f19eb4 | 412 | import_cert(const gnutls_datum_t * cert, gnutls_x509_crt_t * crtp) |
9d1c15ef JH |
413 | { |
414 | int rc; | |
415 | ||
416 | rc = gnutls_x509_crt_init(crtp); | |
417 | exim_gnutls_cert_err(US"gnutls_x509_crt_init (crt)"); | |
418 | ||
419 | rc = gnutls_x509_crt_import(*crtp, cert, GNUTLS_X509_FMT_DER); | |
420 | exim_gnutls_cert_err(US"failed to import certificate [gnutls_x509_crt_import(cert)]"); | |
421 | ||
422 | return rc; | |
423 | } | |
424 | ||
425 | #undef exim_gnutls_cert_err | |
426 | ||
427 | ||
17c76198 PP |
428 | /* We set various Exim global variables from the state, once a session has |
429 | been established. With TLS callouts, may need to change this to stack | |
430 | variables, or just re-call it with the server state after client callout | |
431 | has finished. | |
059ec3d9 | 432 | |
9d1c15ef | 433 | Make sure anything set here is unset in tls_getc(). |
17c76198 PP |
434 | |
435 | Sets: | |
436 | tls_active fd | |
437 | tls_bits strength indicator | |
438 | tls_certificate_verified bool indicator | |
439 | tls_channelbinding_b64 for some SASL mechanisms | |
440 | tls_cipher a string | |
9d1c15ef | 441 | tls_peercert pointer to library internal |
17c76198 PP |
442 | tls_peerdn a string |
443 | tls_sni a (UTF-8) string | |
9d1c15ef | 444 | tls_ourcert pointer to library internal |
17c76198 PP |
445 | |
446 | Argument: | |
447 | state the relevant exim_gnutls_state_st * | |
448 | */ | |
449 | ||
450 | static void | |
9d1c15ef | 451 | extract_exim_vars_from_tls_state(exim_gnutls_state_st * state) |
17c76198 | 452 | { |
17c76198 | 453 | gnutls_cipher_algorithm_t cipher; |
17c76198 PP |
454 | #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING |
455 | int old_pool; | |
456 | int rc; | |
457 | gnutls_datum_t channel; | |
458 | #endif | |
9d1c15ef | 459 | tls_support * tlsp = state->tlsp; |
17c76198 | 460 | |
74f1a423 JH |
461 | tlsp->active.sock = state->fd_out; |
462 | tlsp->active.tls_ctx = state; | |
17c76198 PP |
463 | |
464 | cipher = gnutls_cipher_get(state->session); | |
465 | /* returns size in "bytes" */ | |
9d1c15ef | 466 | tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; |
17c76198 | 467 | |
9d1c15ef | 468 | tlsp->cipher = state->ciphersuite; |
17c76198 | 469 | |
817d9f57 | 470 | DEBUG(D_tls) debug_printf("cipher: %s\n", state->ciphersuite); |
17c76198 | 471 | |
9d1c15ef | 472 | tlsp->certificate_verified = state->peer_cert_verified; |
899b8bbc JH |
473 | #ifdef SUPPORT_DANE |
474 | tlsp->dane_verified = state->peer_dane_verified; | |
475 | #endif | |
059ec3d9 | 476 | |
17c76198 PP |
477 | /* note that tls_channelbinding_b64 is not saved to the spool file, since it's |
478 | only available for use for authenticators while this TLS session is running. */ | |
479 | ||
480 | tls_channelbinding_b64 = NULL; | |
481 | #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING | |
482 | channel.data = NULL; | |
483 | channel.size = 0; | |
1f20760b JH |
484 | if ((rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel))) |
485 | { DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc)); } | |
486 | else | |
487 | { | |
17c76198 PP |
488 | old_pool = store_pool; |
489 | store_pool = POOL_PERM; | |
1f20760b | 490 | tls_channelbinding_b64 = b64encode(CUS channel.data, (int)channel.size); |
17c76198 PP |
491 | store_pool = old_pool; |
492 | DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage.\n"); | |
1f20760b | 493 | } |
17c76198 PP |
494 | #endif |
495 | ||
9d1c15ef JH |
496 | /* peercert is set in peer_status() */ |
497 | tlsp->peerdn = state->peerdn; | |
498 | tlsp->sni = state->received_sni; | |
499 | ||
500 | /* record our certificate */ | |
501 | { | |
27f19eb4 | 502 | const gnutls_datum_t * cert = gnutls_certificate_get_ours(state->session); |
9d1c15ef JH |
503 | gnutls_x509_crt_t crt; |
504 | ||
505 | tlsp->ourcert = cert && import_cert(cert, &crt)==0 ? crt : NULL; | |
506 | } | |
059ec3d9 PH |
507 | } |
508 | ||
509 | ||
510 | ||
17c76198 | 511 | |
059ec3d9 | 512 | /************************************************* |
575643cd | 513 | * Setup up DH parameters * |
059ec3d9 PH |
514 | *************************************************/ |
515 | ||
575643cd | 516 | /* Generating the D-H parameters may take a long time. They only need to |
059ec3d9 PH |
517 | be re-generated every so often, depending on security policy. What we do is to |
518 | keep these parameters in a file in the spool directory. If the file does not | |
519 | exist, we generate them. This means that it is easy to cause a regeneration. | |
520 | ||
521 | The new file is written as a temporary file and renamed, so that an incomplete | |
522 | file is never present. If two processes both compute some new parameters, you | |
523 | waste a bit of effort, but it doesn't seem worth messing around with locking to | |
524 | prevent this. | |
525 | ||
059ec3d9 PH |
526 | Returns: OK/DEFER/FAIL |
527 | */ | |
528 | ||
529 | static int | |
cf0c6164 | 530 | init_server_dh(uschar ** errstr) |
059ec3d9 | 531 | { |
17c76198 PP |
532 | int fd, rc; |
533 | unsigned int dh_bits; | |
27f19eb4 | 534 | gnutls_datum_t m; |
a799883d PP |
535 | uschar filename_buf[PATH_MAX]; |
536 | uschar *filename = NULL; | |
17c76198 | 537 | size_t sz; |
a799883d PP |
538 | uschar *exp_tls_dhparam; |
539 | BOOL use_file_in_spool = FALSE; | |
540 | BOOL use_fixed_file = FALSE; | |
17c76198 | 541 | host_item *host = NULL; /* dummy for macros */ |
059ec3d9 | 542 | |
17c76198 | 543 | DEBUG(D_tls) debug_printf("Initialising GnuTLS server params.\n"); |
059ec3d9 | 544 | |
17c76198 | 545 | rc = gnutls_dh_params_init(&dh_server_params); |
47195144 | 546 | exim_gnutls_err_check(rc, US"gnutls_dh_params_init"); |
059ec3d9 | 547 | |
a799883d PP |
548 | m.data = NULL; |
549 | m.size = 0; | |
550 | ||
cf0c6164 | 551 | if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam, errstr)) |
a799883d PP |
552 | return DEFER; |
553 | ||
554 | if (!exp_tls_dhparam) | |
555 | { | |
556 | DEBUG(D_tls) debug_printf("Loading default hard-coded DH params\n"); | |
557 | m.data = US std_dh_prime_default(); | |
558 | m.size = Ustrlen(m.data); | |
559 | } | |
560 | else if (Ustrcmp(exp_tls_dhparam, "historic") == 0) | |
561 | use_file_in_spool = TRUE; | |
562 | else if (Ustrcmp(exp_tls_dhparam, "none") == 0) | |
563 | { | |
564 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); | |
565 | return OK; | |
566 | } | |
567 | else if (exp_tls_dhparam[0] != '/') | |
568 | { | |
f5d25c2b | 569 | if (!(m.data = US std_dh_prime_named(exp_tls_dhparam))) |
48224640 | 570 | return tls_error(US"No standard prime named", exp_tls_dhparam, NULL, errstr); |
a799883d PP |
571 | m.size = Ustrlen(m.data); |
572 | } | |
573 | else | |
574 | { | |
575 | use_fixed_file = TRUE; | |
576 | filename = exp_tls_dhparam; | |
577 | } | |
578 | ||
579 | if (m.data) | |
580 | { | |
581 | rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM); | |
47195144 | 582 | exim_gnutls_err_check(rc, US"gnutls_dh_params_import_pkcs3"); |
a799883d PP |
583 | DEBUG(D_tls) debug_printf("Loaded fixed standard D-H parameters\n"); |
584 | return OK; | |
585 | } | |
586 | ||
af3498d6 PP |
587 | #ifdef HAVE_GNUTLS_SEC_PARAM_CONSTANTS |
588 | /* If you change this constant, also change dh_param_fn_ext so that we can use a | |
17c76198 PP |
589 | different filename and ensure we have sufficient bits. */ |
590 | dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL); | |
591 | if (!dh_bits) | |
cf0c6164 | 592 | return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL, errstr); |
af3498d6 | 593 | DEBUG(D_tls) |
b34fc30c | 594 | debug_printf("GnuTLS tells us that for D-H PK, NORMAL is %d bits.\n", |
af3498d6 PP |
595 | dh_bits); |
596 | #else | |
597 | dh_bits = EXIM_SERVER_DH_BITS_PRE2_12; | |
598 | DEBUG(D_tls) | |
599 | debug_printf("GnuTLS lacks gnutls_sec_param_to_pk_bits(), using %d bits.\n", | |
600 | dh_bits); | |
601 | #endif | |
059ec3d9 | 602 | |
3375e053 PP |
603 | /* Some clients have hard-coded limits. */ |
604 | if (dh_bits > tls_dh_max_bits) | |
605 | { | |
606 | DEBUG(D_tls) | |
607 | debug_printf("tls_dh_max_bits clamping override, using %d bits instead.\n", | |
608 | tls_dh_max_bits); | |
609 | dh_bits = tls_dh_max_bits; | |
610 | } | |
611 | ||
a799883d PP |
612 | if (use_file_in_spool) |
613 | { | |
614 | if (!string_format(filename_buf, sizeof(filename_buf), | |
615 | "%s/gnutls-params-%d", spool_directory, dh_bits)) | |
cf0c6164 | 616 | return tls_error(US"overlong filename", NULL, NULL, errstr); |
a799883d PP |
617 | filename = filename_buf; |
618 | } | |
059ec3d9 | 619 | |
b5aea5e1 | 620 | /* Open the cache file for reading and if successful, read it and set up the |
575643cd | 621 | parameters. */ |
059ec3d9 | 622 | |
f5d25c2b | 623 | if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) |
059ec3d9 | 624 | { |
b5aea5e1 | 625 | struct stat statbuf; |
17c76198 PP |
626 | FILE *fp; |
627 | int saved_errno; | |
628 | ||
629 | if (fstat(fd, &statbuf) < 0) /* EIO */ | |
630 | { | |
631 | saved_errno = errno; | |
632 | (void)close(fd); | |
48224640 | 633 | return tls_error(US"TLS cache stat failed", US strerror(saved_errno), NULL, errstr); |
17c76198 PP |
634 | } |
635 | if (!S_ISREG(statbuf.st_mode)) | |
b5aea5e1 PH |
636 | { |
637 | (void)close(fd); | |
cf0c6164 | 638 | return tls_error(US"TLS cache not a file", NULL, NULL, errstr); |
17c76198 | 639 | } |
40c90bca | 640 | if (!(fp = fdopen(fd, "rb"))) |
17c76198 PP |
641 | { |
642 | saved_errno = errno; | |
643 | (void)close(fd); | |
644 | return tls_error(US"fdopen(TLS cache stat fd) failed", | |
48224640 | 645 | US strerror(saved_errno), NULL, errstr); |
b5aea5e1 | 646 | } |
059ec3d9 | 647 | |
b5aea5e1 | 648 | m.size = statbuf.st_size; |
40c90bca | 649 | if (!(m.data = malloc(m.size))) |
17c76198 PP |
650 | { |
651 | fclose(fp); | |
48224640 | 652 | return tls_error(US"malloc failed", US strerror(errno), NULL, errstr); |
17c76198 | 653 | } |
40c90bca | 654 | if (!(sz = fread(m.data, m.size, 1, fp))) |
17c76198 PP |
655 | { |
656 | saved_errno = errno; | |
657 | fclose(fp); | |
658 | free(m.data); | |
48224640 | 659 | return tls_error(US"fread failed", US strerror(saved_errno), NULL, errstr); |
17c76198 PP |
660 | } |
661 | fclose(fp); | |
b5aea5e1 | 662 | |
17c76198 | 663 | rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM); |
b5aea5e1 | 664 | free(m.data); |
47195144 | 665 | exim_gnutls_err_check(rc, US"gnutls_dh_params_import_pkcs3"); |
17c76198 | 666 | DEBUG(D_tls) debug_printf("read D-H parameters from file \"%s\"\n", filename); |
b5aea5e1 PH |
667 | } |
668 | ||
669 | /* If the file does not exist, fall through to compute new data and cache it. | |
670 | If there was any other opening error, it is serious. */ | |
671 | ||
182ad5cf PH |
672 | else if (errno == ENOENT) |
673 | { | |
17c76198 | 674 | rc = -1; |
182ad5cf | 675 | DEBUG(D_tls) |
17c76198 | 676 | debug_printf("D-H parameter cache file \"%s\" does not exist\n", filename); |
182ad5cf PH |
677 | } |
678 | else | |
17c76198 | 679 | return tls_error(string_open_failed(errno, "\"%s\" for reading", filename), |
cf0c6164 | 680 | NULL, NULL, errstr); |
b5aea5e1 PH |
681 | |
682 | /* If ret < 0, either the cache file does not exist, or the data it contains | |
683 | is not useful. One particular case of this is when upgrading from an older | |
684 | release of Exim in which the data was stored in a different format. We don't | |
685 | try to be clever and support both formats; we just regenerate new data in this | |
686 | case. */ | |
687 | ||
17c76198 | 688 | if (rc < 0) |
b5aea5e1 | 689 | { |
17c76198 | 690 | uschar *temp_fn; |
201f5254 | 691 | unsigned int dh_bits_gen = dh_bits; |
059ec3d9 | 692 | |
17c76198 PP |
693 | if ((PATH_MAX - Ustrlen(filename)) < 10) |
694 | return tls_error(US"Filename too long to generate replacement", | |
48224640 | 695 | filename, NULL, errstr); |
059ec3d9 | 696 | |
48224640 | 697 | temp_fn = string_copy(US"%s.XXXXXXX"); |
f5d25c2b | 698 | if ((fd = mkstemp(CS temp_fn)) < 0) /* modifies temp_fn */ |
48224640 | 699 | return tls_error(US"Unable to open temp file", US strerror(errno), NULL, errstr); |
059ec3d9 PH |
700 | (void)fchown(fd, exim_uid, exim_gid); /* Probably not necessary */ |
701 | ||
201f5254 PP |
702 | /* GnuTLS overshoots! |
703 | * If we ask for 2236, we might get 2237 or more. | |
704 | * But there's no way to ask GnuTLS how many bits there really are. | |
705 | * We can ask how many bits were used in a TLS session, but that's it! | |
706 | * The prime itself is hidden behind too much abstraction. | |
707 | * So we ask for less, and proceed on a wing and a prayer. | |
708 | * First attempt, subtracted 3 for 2233 and got 2240. | |
709 | */ | |
cae6e576 | 710 | if (dh_bits >= EXIM_CLIENT_DH_MIN_BITS + 10) |
201f5254 PP |
711 | { |
712 | dh_bits_gen = dh_bits - 10; | |
713 | DEBUG(D_tls) | |
714 | debug_printf("being paranoid about DH generation, make it '%d' bits'\n", | |
715 | dh_bits_gen); | |
716 | } | |
717 | ||
718 | DEBUG(D_tls) | |
719 | debug_printf("requesting generation of %d bit Diffie-Hellman prime ...\n", | |
720 | dh_bits_gen); | |
721 | rc = gnutls_dh_params_generate2(dh_server_params, dh_bits_gen); | |
47195144 | 722 | exim_gnutls_err_check(rc, US"gnutls_dh_params_generate2"); |
17c76198 PP |
723 | |
724 | /* gnutls_dh_params_export_pkcs3() will tell us the exact size, every time, | |
725 | and I confirmed that a NULL call to get the size first is how the GnuTLS | |
726 | sample apps handle this. */ | |
727 | ||
728 | sz = 0; | |
729 | m.data = NULL; | |
730 | rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, | |
731 | m.data, &sz); | |
732 | if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) | |
47195144 | 733 | exim_gnutls_err_check(rc, US"gnutls_dh_params_export_pkcs3(NULL) sizing"); |
17c76198 | 734 | m.size = sz; |
40c90bca | 735 | if (!(m.data = malloc(m.size))) |
48224640 | 736 | return tls_error(US"memory allocation failed", US strerror(errno), NULL, errstr); |
40c90bca | 737 | |
1f00591e | 738 | /* this will return a size 1 less than the allocation size above */ |
17c76198 | 739 | rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, |
1f00591e | 740 | m.data, &sz); |
17c76198 PP |
741 | if (rc != GNUTLS_E_SUCCESS) |
742 | { | |
743 | free(m.data); | |
47195144 | 744 | exim_gnutls_err_check(rc, US"gnutls_dh_params_export_pkcs3() real"); |
17c76198 | 745 | } |
1f00591e | 746 | m.size = sz; /* shrink by 1, probably */ |
059ec3d9 | 747 | |
f5d25c2b | 748 | if ((sz = write_to_fd_buf(fd, m.data, (size_t) m.size)) != m.size) |
17c76198 PP |
749 | { |
750 | free(m.data); | |
751 | return tls_error(US"TLS cache write D-H params failed", | |
48224640 | 752 | US strerror(errno), NULL, errstr); |
17c76198 | 753 | } |
b5aea5e1 | 754 | free(m.data); |
f5d25c2b | 755 | if ((sz = write_to_fd_buf(fd, US"\n", 1)) != 1) |
17c76198 | 756 | return tls_error(US"TLS cache write D-H params final newline failed", |
48224640 | 757 | US strerror(errno), NULL, errstr); |
17c76198 | 758 | |
f5d25c2b | 759 | if ((rc = close(fd))) |
48224640 | 760 | return tls_error(US"TLS cache write close() failed", US strerror(errno), NULL, errstr); |
059ec3d9 | 761 | |
17c76198 PP |
762 | if (Urename(temp_fn, filename) < 0) |
763 | return tls_error(string_sprintf("failed to rename \"%s\" as \"%s\"", | |
48224640 | 764 | temp_fn, filename), US strerror(errno), NULL, errstr); |
059ec3d9 | 765 | |
17c76198 | 766 | DEBUG(D_tls) debug_printf("wrote D-H parameters to file \"%s\"\n", filename); |
059ec3d9 PH |
767 | } |
768 | ||
17c76198 | 769 | DEBUG(D_tls) debug_printf("initialized server D-H parameters\n"); |
059ec3d9 PH |
770 | return OK; |
771 | } | |
772 | ||
773 | ||
774 | ||
775 | ||
23bb6982 JH |
776 | /* Create and install a selfsigned certificate, for use in server mode */ |
777 | ||
778 | static int | |
cf0c6164 | 779 | tls_install_selfsign(exim_gnutls_state_st * state, uschar ** errstr) |
23bb6982 JH |
780 | { |
781 | gnutls_x509_crt_t cert = NULL; | |
782 | time_t now; | |
783 | gnutls_x509_privkey_t pkey = NULL; | |
784 | const uschar * where; | |
785 | int rc; | |
786 | ||
787 | where = US"initialising pkey"; | |
788 | if ((rc = gnutls_x509_privkey_init(&pkey))) goto err; | |
789 | ||
790 | where = US"initialising cert"; | |
791 | if ((rc = gnutls_x509_crt_init(&cert))) goto err; | |
792 | ||
793 | where = US"generating pkey"; | |
794 | if ((rc = gnutls_x509_privkey_generate(pkey, GNUTLS_PK_RSA, | |
76075bb5 | 795 | #ifdef SUPPORT_PARAM_TO_PK_BITS |
4312da48 JH |
796 | # ifndef GNUTLS_SEC_PARAM_MEDIUM |
797 | # define GNUTLS_SEC_PARAM_MEDIUM GNUTLS_SEC_PARAM_HIGH | |
798 | # endif | |
6aac3239 | 799 | gnutls_sec_param_to_pk_bits(GNUTLS_PK_RSA, GNUTLS_SEC_PARAM_MEDIUM), |
76075bb5 | 800 | #else |
6aac3239 | 801 | 2048, |
76075bb5 JH |
802 | #endif |
803 | 0))) | |
23bb6982 JH |
804 | goto err; |
805 | ||
806 | where = US"configuring cert"; | |
1613fd68 | 807 | now = 1; |
23bb6982 JH |
808 | if ( (rc = gnutls_x509_crt_set_version(cert, 3)) |
809 | || (rc = gnutls_x509_crt_set_serial(cert, &now, sizeof(now))) | |
810 | || (rc = gnutls_x509_crt_set_activation_time(cert, now = time(NULL))) | |
811 | || (rc = gnutls_x509_crt_set_expiration_time(cert, now + 60 * 60)) /* 1 hr */ | |
812 | || (rc = gnutls_x509_crt_set_key(cert, pkey)) | |
813 | ||
814 | || (rc = gnutls_x509_crt_set_dn_by_oid(cert, | |
815 | GNUTLS_OID_X520_COUNTRY_NAME, 0, "UK", 2)) | |
816 | || (rc = gnutls_x509_crt_set_dn_by_oid(cert, | |
817 | GNUTLS_OID_X520_ORGANIZATION_NAME, 0, "Exim Developers", 15)) | |
818 | || (rc = gnutls_x509_crt_set_dn_by_oid(cert, | |
819 | GNUTLS_OID_X520_COMMON_NAME, 0, | |
820 | smtp_active_hostname, Ustrlen(smtp_active_hostname))) | |
821 | ) | |
822 | goto err; | |
823 | ||
824 | where = US"signing cert"; | |
825 | if ((rc = gnutls_x509_crt_sign(cert, cert, pkey))) goto err; | |
826 | ||
827 | where = US"installing selfsign cert"; | |
828 | /* Since: 2.4.0 */ | |
829 | if ((rc = gnutls_certificate_set_x509_key(state->x509_cred, &cert, 1, pkey))) | |
830 | goto err; | |
831 | ||
832 | rc = OK; | |
833 | ||
834 | out: | |
835 | if (cert) gnutls_x509_crt_deinit(cert); | |
836 | if (pkey) gnutls_x509_privkey_deinit(pkey); | |
837 | return rc; | |
838 | ||
839 | err: | |
48224640 | 840 | rc = tls_error(where, US gnutls_strerror(rc), NULL, errstr); |
23bb6982 JH |
841 | goto out; |
842 | } | |
843 | ||
844 | ||
845 | ||
846 | ||
47195144 JH |
847 | /* Add certificate and key, from files. |
848 | ||
849 | Return: | |
850 | Zero or negative: good. Negate value for certificate index if < 0. | |
851 | Greater than zero: FAIL or DEFER code. | |
852 | */ | |
853 | ||
ba86e143 JH |
854 | static int |
855 | tls_add_certfile(exim_gnutls_state_st * state, const host_item * host, | |
856 | uschar * certfile, uschar * keyfile, uschar ** errstr) | |
857 | { | |
858 | int rc = gnutls_certificate_set_x509_key_file(state->x509_cred, | |
859 | CS certfile, CS keyfile, GNUTLS_X509_FMT_PEM); | |
47195144 JH |
860 | if (rc < 0) |
861 | return tls_error( | |
862 | string_sprintf("cert/key setup: cert=%s key=%s", certfile, keyfile), | |
48224640 | 863 | US gnutls_strerror(rc), host, errstr); |
47195144 | 864 | return -rc; |
ba86e143 JH |
865 | } |
866 | ||
867 | ||
059ec3d9 | 868 | /************************************************* |
17c76198 | 869 | * Variables re-expanded post-SNI * |
059ec3d9 PH |
870 | *************************************************/ |
871 | ||
17c76198 PP |
872 | /* Called from both server and client code, via tls_init(), and also from |
873 | the SNI callback after receiving an SNI, if tls_certificate includes "tls_sni". | |
874 | ||
875 | We can tell the two apart by state->received_sni being non-NULL in callback. | |
876 | ||
877 | The callback should not call us unless state->trigger_sni_changes is true, | |
878 | which we are responsible for setting on the first pass through. | |
059ec3d9 PH |
879 | |
880 | Arguments: | |
17c76198 | 881 | state exim_gnutls_state_st * |
cf0c6164 | 882 | errstr error string pointer |
059ec3d9 PH |
883 | |
884 | Returns: OK/DEFER/FAIL | |
885 | */ | |
886 | ||
887 | static int | |
ba86e143 | 888 | tls_expand_session_files(exim_gnutls_state_st * state, uschar ** errstr) |
059ec3d9 | 889 | { |
1365611d | 890 | struct stat statbuf; |
059ec3d9 | 891 | int rc; |
17c76198 PP |
892 | const host_item *host = state->host; /* macro should be reconsidered? */ |
893 | uschar *saved_tls_certificate = NULL; | |
894 | uschar *saved_tls_privatekey = NULL; | |
895 | uschar *saved_tls_verify_certificates = NULL; | |
896 | uschar *saved_tls_crl = NULL; | |
897 | int cert_count; | |
898 | ||
899 | /* We check for tls_sni *before* expansion. */ | |
2b4a568d | 900 | if (!host) /* server */ |
17c76198 PP |
901 | if (!state->received_sni) |
902 | { | |
ba86e143 JH |
903 | if ( state->tls_certificate |
904 | && ( Ustrstr(state->tls_certificate, US"tls_sni") | |
905 | || Ustrstr(state->tls_certificate, US"tls_in_sni") | |
906 | || Ustrstr(state->tls_certificate, US"tls_out_sni") | |
907 | ) ) | |
17c76198 PP |
908 | { |
909 | DEBUG(D_tls) debug_printf("We will re-expand TLS session files if we receive SNI.\n"); | |
910 | state->trigger_sni_changes = TRUE; | |
911 | } | |
912 | } | |
913 | else | |
914 | { | |
1365611d | 915 | /* useful for debugging */ |
17c76198 PP |
916 | saved_tls_certificate = state->exp_tls_certificate; |
917 | saved_tls_privatekey = state->exp_tls_privatekey; | |
918 | saved_tls_verify_certificates = state->exp_tls_verify_certificates; | |
919 | saved_tls_crl = state->exp_tls_crl; | |
920 | } | |
059ec3d9 | 921 | |
1365611d | 922 | rc = gnutls_certificate_allocate_credentials(&state->x509_cred); |
47195144 JH |
923 | exim_gnutls_err_check(rc, US"gnutls_certificate_allocate_credentials"); |
924 | ||
925 | #ifdef SUPPORT_SRV_OCSP_STACK | |
926 | gnutls_certificate_set_flags(state->x509_cred, GNUTLS_CERTIFICATE_API_V2); | |
927 | #endif | |
1365611d | 928 | |
17c76198 PP |
929 | /* remember: expand_check_tlsvar() is expand_check() but fiddling with |
930 | state members, assuming consistent naming; and expand_check() returns | |
931 | false if expansion failed, unless expansion was forced to fail. */ | |
059ec3d9 | 932 | |
17c76198 PP |
933 | /* check if we at least have a certificate, before doing expensive |
934 | D-H generation. */ | |
059ec3d9 | 935 | |
cf0c6164 | 936 | if (!expand_check_tlsvar(tls_certificate, errstr)) |
17c76198 | 937 | return DEFER; |
059ec3d9 | 938 | |
17c76198 | 939 | /* certificate is mandatory in server, optional in client */ |
059ec3d9 | 940 | |
23bb6982 JH |
941 | if ( !state->exp_tls_certificate |
942 | || !*state->exp_tls_certificate | |
943 | ) | |
2b4a568d | 944 | if (!host) |
cf0c6164 | 945 | return tls_install_selfsign(state, errstr); |
17c76198 PP |
946 | else |
947 | DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n"); | |
059ec3d9 | 948 | |
cf0c6164 | 949 | if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey, errstr)) |
059ec3d9 PH |
950 | return DEFER; |
951 | ||
17c76198 PP |
952 | /* tls_privatekey is optional, defaulting to same file as certificate */ |
953 | ||
954 | if (state->tls_privatekey == NULL || *state->tls_privatekey == '\0') | |
059ec3d9 | 955 | { |
17c76198 PP |
956 | state->tls_privatekey = state->tls_certificate; |
957 | state->exp_tls_privatekey = state->exp_tls_certificate; | |
059ec3d9 | 958 | } |
c91535f3 | 959 | |
059ec3d9 | 960 | |
17c76198 | 961 | if (state->exp_tls_certificate && *state->exp_tls_certificate) |
059ec3d9 PH |
962 | { |
963 | DEBUG(D_tls) debug_printf("certificate file = %s\nkey file = %s\n", | |
17c76198 PP |
964 | state->exp_tls_certificate, state->exp_tls_privatekey); |
965 | ||
966 | if (state->received_sni) | |
23bb6982 JH |
967 | if ( Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0 |
968 | && Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0 | |
969 | ) | |
17c76198 | 970 | { |
b34fc30c | 971 | DEBUG(D_tls) debug_printf("TLS SNI: cert and key unchanged\n"); |
17c76198 PP |
972 | } |
973 | else | |
974 | { | |
b34fc30c | 975 | DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair.\n"); |
17c76198 | 976 | } |
059ec3d9 | 977 | |
ba86e143 JH |
978 | if (!host) /* server */ |
979 | { | |
980 | const uschar * clist = state->exp_tls_certificate; | |
981 | const uschar * klist = state->exp_tls_privatekey; | |
47195144 JH |
982 | const uschar * olist; |
983 | int csep = 0, ksep = 0, osep = 0, cnt = 0; | |
984 | uschar * cfile, * kfile, * ofile; | |
985 | ||
986 | #ifndef DISABLE_OCSP | |
987 | if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", &ofile, errstr)) | |
988 | return DEFER; | |
989 | olist = ofile; | |
990 | #endif | |
ba86e143 JH |
991 | |
992 | while (cfile = string_nextinlist(&clist, &csep, NULL, 0)) | |
47195144 | 993 | |
ba86e143 JH |
994 | if (!(kfile = string_nextinlist(&klist, &ksep, NULL, 0))) |
995 | return tls_error(US"cert/key setup: out of keys", NULL, host, errstr); | |
47195144 | 996 | else if (0 < (rc = tls_add_certfile(state, host, cfile, kfile, errstr))) |
ba86e143 JH |
997 | return rc; |
998 | else | |
47195144 JH |
999 | { |
1000 | int gnutls_cert_index = -rc; | |
ba86e143 | 1001 | DEBUG(D_tls) debug_printf("TLS: cert/key %s registered\n", cfile); |
47195144 JH |
1002 | |
1003 | /* Set the OCSP stapling server info */ | |
1004 | ||
1005 | #ifndef DISABLE_OCSP | |
1006 | if (tls_ocsp_file) | |
1007 | if (gnutls_buggy_ocsp) | |
1008 | { | |
1009 | DEBUG(D_tls) | |
1010 | debug_printf("GnuTLS library is buggy for OCSP; avoiding\n"); | |
1011 | } | |
1012 | else if ((ofile = string_nextinlist(&olist, &osep, NULL, 0))) | |
1013 | { | |
1014 | /* Use the full callback method for stapling just to get | |
1015 | observability. More efficient would be to read the file once only, | |
1016 | if it never changed (due to SNI). Would need restart on file update, | |
1017 | or watch datestamp. */ | |
1018 | ||
1019 | # ifdef SUPPORT_SRV_OCSP_STACK | |
1020 | rc = gnutls_certificate_set_ocsp_status_request_function2( | |
1021 | state->x509_cred, gnutls_cert_index, | |
1022 | server_ocsp_stapling_cb, ofile); | |
1023 | ||
1024 | exim_gnutls_err_check(rc, | |
1025 | US"gnutls_certificate_set_ocsp_status_request_function2"); | |
1026 | # else | |
1027 | if (cnt++ > 0) | |
1028 | { | |
1029 | DEBUG(D_tls) | |
1030 | debug_printf("oops; multiple OCSP files not supported\n"); | |
1031 | break; | |
1032 | } | |
1033 | gnutls_certificate_set_ocsp_status_request_function( | |
1034 | state->x509_cred, server_ocsp_stapling_cb, ofile); | |
1035 | # endif | |
1036 | ||
1037 | DEBUG(D_tls) debug_printf("OCSP response file = %s\n", ofile); | |
1038 | } | |
1039 | else | |
1040 | DEBUG(D_tls) debug_printf("ran out of OCSP response files in list\n"); | |
1041 | #endif | |
1042 | } | |
ba86e143 JH |
1043 | } |
1044 | else | |
1045 | { | |
47195144 | 1046 | if (0 < (rc = tls_add_certfile(state, host, |
ba86e143 JH |
1047 | state->exp_tls_certificate, state->exp_tls_privatekey, errstr))) |
1048 | return rc; | |
1049 | DEBUG(D_tls) debug_printf("TLS: cert/key registered\n"); | |
1050 | } | |
1051 | ||
b34fc30c | 1052 | } /* tls_certificate */ |
059ec3d9 | 1053 | |
2b4a568d | 1054 | |
059ec3d9 PH |
1055 | /* Set the trusted CAs file if one is provided, and then add the CRL if one is |
1056 | provided. Experiment shows that, if the certificate file is empty, an unhelpful | |
1057 | error message is provided. However, if we just refrain from setting anything up | |
1058 | in that case, certificate verification fails, which seems to be the correct | |
1059 | behaviour. */ | |
1060 | ||
610ff438 | 1061 | if (state->tls_verify_certificates && *state->tls_verify_certificates) |
059ec3d9 | 1062 | { |
cf0c6164 | 1063 | if (!expand_check_tlsvar(tls_verify_certificates, errstr)) |
059ec3d9 | 1064 | return DEFER; |
610ff438 JH |
1065 | #ifndef SUPPORT_SYSDEFAULT_CABUNDLE |
1066 | if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) | |
1067 | state->exp_tls_verify_certificates = NULL; | |
1068 | #endif | |
17c76198 | 1069 | if (state->tls_crl && *state->tls_crl) |
cf0c6164 | 1070 | if (!expand_check_tlsvar(tls_crl, errstr)) |
17c76198 | 1071 | return DEFER; |
059ec3d9 | 1072 | |
1365611d PP |
1073 | if (!(state->exp_tls_verify_certificates && |
1074 | *state->exp_tls_verify_certificates)) | |
b34fc30c PP |
1075 | { |
1076 | DEBUG(D_tls) | |
1365611d PP |
1077 | debug_printf("TLS: tls_verify_certificates expanded empty, ignoring\n"); |
1078 | /* With no tls_verify_certificates, we ignore tls_crl too */ | |
17c76198 | 1079 | return OK; |
b34fc30c | 1080 | } |
1365611d | 1081 | } |
83e2f8a2 PP |
1082 | else |
1083 | { | |
1084 | DEBUG(D_tls) | |
1085 | debug_printf("TLS: tls_verify_certificates not set or empty, ignoring\n"); | |
1086 | return OK; | |
1087 | } | |
17c76198 | 1088 | |
cb1d7830 JH |
1089 | #ifdef SUPPORT_SYSDEFAULT_CABUNDLE |
1090 | if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) | |
1091 | cert_count = gnutls_certificate_set_x509_system_trust(state->x509_cred); | |
1092 | else | |
1093 | #endif | |
1365611d | 1094 | { |
cb1d7830 JH |
1095 | if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0) |
1096 | { | |
1097 | log_write(0, LOG_MAIN|LOG_PANIC, "could not stat %s " | |
1098 | "(tls_verify_certificates): %s", state->exp_tls_verify_certificates, | |
1099 | strerror(errno)); | |
1100 | return DEFER; | |
1101 | } | |
17c76198 | 1102 | |
a7fec7a7 | 1103 | #ifndef SUPPORT_CA_DIR |
cb1d7830 JH |
1104 | /* The test suite passes in /dev/null; we could check for that path explicitly, |
1105 | but who knows if someone has some weird FIFO which always dumps some certs, or | |
1106 | other weirdness. The thing we really want to check is that it's not a | |
1107 | directory, since while OpenSSL supports that, GnuTLS does not. | |
60f914bc | 1108 | So s/!S_ISREG/S_ISDIR/ and change some messaging ... */ |
cb1d7830 JH |
1109 | if (S_ISDIR(statbuf.st_mode)) |
1110 | { | |
1111 | DEBUG(D_tls) | |
1112 | debug_printf("verify certificates path is a dir: \"%s\"\n", | |
1113 | state->exp_tls_verify_certificates); | |
1114 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1115 | "tls_verify_certificates \"%s\" is a directory", | |
1116 | state->exp_tls_verify_certificates); | |
1117 | return DEFER; | |
1118 | } | |
a7fec7a7 | 1119 | #endif |
059ec3d9 | 1120 | |
cb1d7830 JH |
1121 | DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n", |
1122 | state->exp_tls_verify_certificates, statbuf.st_size); | |
059ec3d9 | 1123 | |
cb1d7830 JH |
1124 | if (statbuf.st_size == 0) |
1125 | { | |
1126 | DEBUG(D_tls) | |
1127 | debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n"); | |
1128 | return OK; | |
1129 | } | |
059ec3d9 | 1130 | |
cb1d7830 | 1131 | cert_count = |
a7fec7a7 JH |
1132 | |
1133 | #ifdef SUPPORT_CA_DIR | |
cb1d7830 JH |
1134 | (statbuf.st_mode & S_IFMT) == S_IFDIR |
1135 | ? | |
1136 | gnutls_certificate_set_x509_trust_dir(state->x509_cred, | |
1137 | CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM) | |
1138 | : | |
a7fec7a7 | 1139 | #endif |
cb1d7830 JH |
1140 | gnutls_certificate_set_x509_trust_file(state->x509_cred, |
1141 | CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM); | |
1142 | } | |
a7fec7a7 | 1143 | |
1365611d PP |
1144 | if (cert_count < 0) |
1145 | { | |
1146 | rc = cert_count; | |
47195144 | 1147 | exim_gnutls_err_check(rc, US"setting certificate trust"); |
1365611d PP |
1148 | } |
1149 | DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", cert_count); | |
059ec3d9 | 1150 | |
5c8cda3a PP |
1151 | if (state->tls_crl && *state->tls_crl && |
1152 | state->exp_tls_crl && *state->exp_tls_crl) | |
1365611d | 1153 | { |
5c8cda3a PP |
1154 | DEBUG(D_tls) debug_printf("loading CRL file = %s\n", state->exp_tls_crl); |
1155 | cert_count = gnutls_certificate_set_x509_crl_file(state->x509_cred, | |
1156 | CS state->exp_tls_crl, GNUTLS_X509_FMT_PEM); | |
1157 | if (cert_count < 0) | |
1365611d | 1158 | { |
5c8cda3a | 1159 | rc = cert_count; |
47195144 | 1160 | exim_gnutls_err_check(rc, US"gnutls_certificate_set_x509_crl_file"); |
1365611d | 1161 | } |
5c8cda3a | 1162 | DEBUG(D_tls) debug_printf("Processed %d CRLs.\n", cert_count); |
1365611d | 1163 | } |
059ec3d9 | 1164 | |
059ec3d9 PH |
1165 | return OK; |
1166 | } | |
1167 | ||
1168 | ||
1169 | ||
1170 | ||
1365611d PP |
1171 | /************************************************* |
1172 | * Set X.509 state variables * | |
1173 | *************************************************/ | |
1174 | ||
1175 | /* In GnuTLS, the registered cert/key are not replaced by a later | |
1176 | set of a cert/key, so for SNI support we need a whole new x509_cred | |
1177 | structure. Which means various other non-re-expanded pieces of state | |
1178 | need to be re-set in the new struct, so the setting logic is pulled | |
1179 | out to this. | |
1180 | ||
1181 | Arguments: | |
1182 | state exim_gnutls_state_st * | |
cf0c6164 | 1183 | errstr error string pointer |
1365611d PP |
1184 | |
1185 | Returns: OK/DEFER/FAIL | |
1186 | */ | |
1187 | ||
1188 | static int | |
cf0c6164 | 1189 | tls_set_remaining_x509(exim_gnutls_state_st *state, uschar ** errstr) |
1365611d PP |
1190 | { |
1191 | int rc; | |
1192 | const host_item *host = state->host; /* macro should be reconsidered? */ | |
1193 | ||
1194 | /* Create D-H parameters, or read them from the cache file. This function does | |
1195 | its own SMTP error messaging. This only happens for the server, TLS D-H ignores | |
1196 | client-side params. */ | |
1197 | ||
1198 | if (!state->host) | |
1199 | { | |
1200 | if (!dh_server_params) | |
1201 | { | |
cf0c6164 | 1202 | rc = init_server_dh(errstr); |
1365611d PP |
1203 | if (rc != OK) return rc; |
1204 | } | |
1205 | gnutls_certificate_set_dh_params(state->x509_cred, dh_server_params); | |
1206 | } | |
1207 | ||
1208 | /* Link the credentials to the session. */ | |
1209 | ||
1210 | rc = gnutls_credentials_set(state->session, GNUTLS_CRD_CERTIFICATE, state->x509_cred); | |
47195144 | 1211 | exim_gnutls_err_check(rc, US"gnutls_credentials_set"); |
1365611d PP |
1212 | |
1213 | return OK; | |
1214 | } | |
1215 | ||
059ec3d9 | 1216 | /************************************************* |
17c76198 | 1217 | * Initialize for GnuTLS * |
059ec3d9 PH |
1218 | *************************************************/ |
1219 | ||
9196d5bf | 1220 | |
4fb7df6d JH |
1221 | #ifndef DISABLE_OCSP |
1222 | ||
9196d5bf JH |
1223 | static BOOL |
1224 | tls_is_buggy_ocsp(void) | |
1225 | { | |
1226 | const uschar * s; | |
1227 | uschar maj, mid, mic; | |
1228 | ||
1229 | s = CUS gnutls_check_version(NULL); | |
1230 | maj = atoi(CCS s); | |
1231 | if (maj == 3) | |
1232 | { | |
1233 | while (*s && *s != '.') s++; | |
1234 | mid = atoi(CCS ++s); | |
1235 | if (mid <= 2) | |
1236 | return TRUE; | |
1237 | else if (mid >= 5) | |
1238 | return FALSE; | |
1239 | else | |
1240 | { | |
1241 | while (*s && *s != '.') s++; | |
1242 | mic = atoi(CCS ++s); | |
1243 | return mic <= (mid == 3 ? 16 : 3); | |
1244 | } | |
1245 | } | |
1246 | return FALSE; | |
1247 | } | |
1248 | ||
4fb7df6d | 1249 | #endif |
9196d5bf JH |
1250 | |
1251 | ||
17c76198 PP |
1252 | /* Called from both server and client code. In the case of a server, errors |
1253 | before actual TLS negotiation return DEFER. | |
059ec3d9 PH |
1254 | |
1255 | Arguments: | |
17c76198 PP |
1256 | host connected host, if client; NULL if server |
1257 | certificate certificate file | |
1258 | privatekey private key file | |
1259 | sni TLS SNI to send, sometimes when client; else NULL | |
1260 | cas CA certs file | |
1261 | crl CRL file | |
1262 | require_ciphers tls_require_ciphers setting | |
817d9f57 | 1263 | caller_state returned state-info structure |
cf0c6164 | 1264 | errstr error string pointer |
059ec3d9 | 1265 | |
17c76198 | 1266 | Returns: OK/DEFER/FAIL |
059ec3d9 PH |
1267 | */ |
1268 | ||
17c76198 PP |
1269 | static int |
1270 | tls_init( | |
1271 | const host_item *host, | |
1272 | const uschar *certificate, | |
1273 | const uschar *privatekey, | |
1274 | const uschar *sni, | |
1275 | const uschar *cas, | |
1276 | const uschar *crl, | |
1277 | const uschar *require_ciphers, | |
cf0c6164 | 1278 | exim_gnutls_state_st **caller_state, |
74f1a423 | 1279 | tls_support * tlsp, |
cf0c6164 | 1280 | uschar ** errstr) |
059ec3d9 | 1281 | { |
17c76198 PP |
1282 | exim_gnutls_state_st *state; |
1283 | int rc; | |
1284 | size_t sz; | |
1285 | const char *errpos; | |
1286 | uschar *p; | |
1287 | BOOL want_default_priorities; | |
1288 | ||
1289 | if (!exim_gnutls_base_init_done) | |
059ec3d9 | 1290 | { |
17c76198 PP |
1291 | DEBUG(D_tls) debug_printf("GnuTLS global init required.\n"); |
1292 | ||
a5f239e4 PP |
1293 | #ifdef HAVE_GNUTLS_PKCS11 |
1294 | /* By default, gnutls_global_init will init PKCS11 support in auto mode, | |
1295 | which loads modules from a config file, which sounds good and may be wanted | |
1296 | by some sysadmin, but also means in common configurations that GNOME keyring | |
1297 | environment variables are used and so breaks for users calling mailq. | |
1298 | To prevent this, we init PKCS11 first, which is the documented approach. */ | |
2519e60d | 1299 | if (!gnutls_allow_auto_pkcs11) |
a5f239e4 PP |
1300 | { |
1301 | rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL); | |
47195144 | 1302 | exim_gnutls_err_check(rc, US"gnutls_pkcs11_init"); |
a5f239e4 PP |
1303 | } |
1304 | #endif | |
1305 | ||
17c76198 | 1306 | rc = gnutls_global_init(); |
47195144 | 1307 | exim_gnutls_err_check(rc, US"gnutls_global_init"); |
17c76198 PP |
1308 | |
1309 | #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 | |
1310 | DEBUG(D_tls) | |
059ec3d9 | 1311 | { |
17c76198 | 1312 | gnutls_global_set_log_function(exim_gnutls_logger_cb); |
aded2255 | 1313 | /* arbitrarily chosen level; bump up to 9 for more */ |
17c76198 | 1314 | gnutls_global_set_log_level(EXIM_GNUTLS_LIBRARY_LOG_LEVEL); |
059ec3d9 | 1315 | } |
17c76198 PP |
1316 | #endif |
1317 | ||
4fb7df6d JH |
1318 | #ifndef DISABLE_OCSP |
1319 | if (tls_ocsp_file && (gnutls_buggy_ocsp = tls_is_buggy_ocsp())) | |
9196d5bf | 1320 | log_write(0, LOG_MAIN, "OCSP unusable with this GnuTLS library version"); |
4fb7df6d | 1321 | #endif |
9196d5bf | 1322 | |
17c76198 | 1323 | exim_gnutls_base_init_done = TRUE; |
059ec3d9 | 1324 | } |
059ec3d9 | 1325 | |
17c76198 PP |
1326 | if (host) |
1327 | { | |
74f1a423 JH |
1328 | /* For client-side sessions we allocate a context. This lets us run |
1329 | several in parallel. */ | |
1330 | int old_pool = store_pool; | |
1331 | store_pool = POOL_PERM; | |
1332 | state = store_get(sizeof(exim_gnutls_state_st)); | |
1333 | store_pool = old_pool; | |
1334 | ||
17c76198 | 1335 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); |
74f1a423 | 1336 | state->tlsp = tlsp; |
17c76198 PP |
1337 | DEBUG(D_tls) debug_printf("initialising GnuTLS client session\n"); |
1338 | rc = gnutls_init(&state->session, GNUTLS_CLIENT); | |
1339 | } | |
1340 | else | |
1341 | { | |
1342 | state = &state_server; | |
1343 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); | |
74f1a423 | 1344 | state->tlsp = tlsp; |
17c76198 PP |
1345 | DEBUG(D_tls) debug_printf("initialising GnuTLS server session\n"); |
1346 | rc = gnutls_init(&state->session, GNUTLS_SERVER); | |
1347 | } | |
47195144 | 1348 | exim_gnutls_err_check(rc, US"gnutls_init"); |
059ec3d9 | 1349 | |
17c76198 | 1350 | state->host = host; |
059ec3d9 | 1351 | |
17c76198 PP |
1352 | state->tls_certificate = certificate; |
1353 | state->tls_privatekey = privatekey; | |
5779e6aa | 1354 | state->tls_require_ciphers = require_ciphers; |
17c76198 PP |
1355 | state->tls_sni = sni; |
1356 | state->tls_verify_certificates = cas; | |
1357 | state->tls_crl = crl; | |
059ec3d9 | 1358 | |
17c76198 PP |
1359 | /* This handles the variables that might get re-expanded after TLS SNI; |
1360 | that's tls_certificate, tls_privatekey, tls_verify_certificates, tls_crl */ | |
059ec3d9 | 1361 | |
17c76198 PP |
1362 | DEBUG(D_tls) |
1363 | debug_printf("Expanding various TLS configuration options for session credentials.\n"); | |
cf0c6164 | 1364 | if ((rc = tls_expand_session_files(state, errstr)) != OK) return rc; |
059ec3d9 | 1365 | |
1365611d PP |
1366 | /* These are all other parts of the x509_cred handling, since SNI in GnuTLS |
1367 | requires a new structure afterwards. */ | |
83da1223 | 1368 | |
cf0c6164 | 1369 | if ((rc = tls_set_remaining_x509(state, errstr)) != OK) return rc; |
83da1223 | 1370 | |
17c76198 PP |
1371 | /* set SNI in client, only */ |
1372 | if (host) | |
1373 | { | |
cf0c6164 | 1374 | if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni, errstr)) |
17c76198 | 1375 | return DEFER; |
0df4ab80 | 1376 | if (state->tlsp->sni && *state->tlsp->sni) |
17c76198 PP |
1377 | { |
1378 | DEBUG(D_tls) | |
0df4ab80 JH |
1379 | debug_printf("Setting TLS client SNI to \"%s\"\n", state->tlsp->sni); |
1380 | sz = Ustrlen(state->tlsp->sni); | |
17c76198 | 1381 | rc = gnutls_server_name_set(state->session, |
0df4ab80 | 1382 | GNUTLS_NAME_DNS, state->tlsp->sni, sz); |
47195144 | 1383 | exim_gnutls_err_check(rc, US"gnutls_server_name_set"); |
17c76198 PP |
1384 | } |
1385 | } | |
1386 | else if (state->tls_sni) | |
1387 | DEBUG(D_tls) debug_printf("*** PROBABLY A BUG *** " \ | |
ba86e143 | 1388 | "have an SNI set for a server [%s]\n", state->tls_sni); |
83da1223 | 1389 | |
17c76198 | 1390 | /* This is the priority string support, |
42bfef1e | 1391 | http://www.gnutls.org/manual/html_node/Priority-Strings.html |
17c76198 PP |
1392 | and replaces gnutls_require_kx, gnutls_require_mac & gnutls_require_protocols. |
1393 | This was backwards incompatible, but means Exim no longer needs to track | |
1394 | all algorithms and provide string forms for them. */ | |
83da1223 | 1395 | |
17c76198 | 1396 | want_default_priorities = TRUE; |
83da1223 | 1397 | |
17c76198 | 1398 | if (state->tls_require_ciphers && *state->tls_require_ciphers) |
83da1223 | 1399 | { |
cf0c6164 | 1400 | if (!expand_check_tlsvar(tls_require_ciphers, errstr)) |
17c76198 PP |
1401 | return DEFER; |
1402 | if (state->exp_tls_require_ciphers && *state->exp_tls_require_ciphers) | |
83da1223 | 1403 | { |
17c76198 PP |
1404 | DEBUG(D_tls) debug_printf("GnuTLS session cipher/priority \"%s\"\n", |
1405 | state->exp_tls_require_ciphers); | |
1406 | ||
1407 | rc = gnutls_priority_init(&state->priority_cache, | |
1408 | CS state->exp_tls_require_ciphers, &errpos); | |
1409 | want_default_priorities = FALSE; | |
1410 | p = state->exp_tls_require_ciphers; | |
83da1223 PH |
1411 | } |
1412 | } | |
17c76198 PP |
1413 | if (want_default_priorities) |
1414 | { | |
83e2f8a2 PP |
1415 | DEBUG(D_tls) |
1416 | debug_printf("GnuTLS using default session cipher/priority \"%s\"\n", | |
1417 | exim_default_gnutls_priority); | |
17c76198 PP |
1418 | rc = gnutls_priority_init(&state->priority_cache, |
1419 | exim_default_gnutls_priority, &errpos); | |
1420 | p = US exim_default_gnutls_priority; | |
1421 | } | |
83da1223 | 1422 | |
47195144 | 1423 | exim_gnutls_err_check(rc, string_sprintf( |
17c76198 PP |
1424 | "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"", |
1425 | p, errpos - CS p, errpos)); | |
1426 | ||
1427 | rc = gnutls_priority_set(state->session, state->priority_cache); | |
47195144 | 1428 | exim_gnutls_err_check(rc, US"gnutls_priority_set"); |
17c76198 PP |
1429 | |
1430 | gnutls_db_set_cache_expiration(state->session, ssl_session_timeout); | |
1431 | ||
1432 | /* Reduce security in favour of increased compatibility, if the admin | |
1433 | decides to make that trade-off. */ | |
1434 | if (gnutls_compat_mode) | |
83da1223 | 1435 | { |
17c76198 PP |
1436 | #if LIBGNUTLS_VERSION_NUMBER >= 0x020104 |
1437 | DEBUG(D_tls) debug_printf("lowering GnuTLS security, compatibility mode\n"); | |
1438 | gnutls_session_enable_compatibility_mode(state->session); | |
1439 | #else | |
1440 | DEBUG(D_tls) debug_printf("Unable to set gnutls_compat_mode - GnuTLS version too old\n"); | |
1441 | #endif | |
83da1223 PH |
1442 | } |
1443 | ||
17c76198 | 1444 | *caller_state = state; |
17c76198 | 1445 | return OK; |
83da1223 PH |
1446 | } |
1447 | ||
1448 | ||
1449 | ||
059ec3d9 | 1450 | /************************************************* |
17c76198 | 1451 | * Extract peer information * |
059ec3d9 PH |
1452 | *************************************************/ |
1453 | ||
17c76198 | 1454 | /* Called from both server and client code. |
4fe99a6c PP |
1455 | Only this is allowed to set state->peerdn and state->have_set_peerdn |
1456 | and we use that to detect double-calls. | |
059ec3d9 | 1457 | |
75fe387d PP |
1458 | NOTE: the state blocks last while the TLS connection is up, which is fine |
1459 | for logging in the server side, but for the client side, we log after teardown | |
1460 | in src/deliver.c. While the session is up, we can twist about states and | |
1461 | repoint tls_* globals, but those variables used for logging or other variable | |
1462 | expansion that happens _after_ delivery need to have a longer life-time. | |
1463 | ||
1464 | So for those, we get the data from POOL_PERM; the re-invoke guard keeps us from | |
1465 | doing this more than once per generation of a state context. We set them in | |
1466 | the state context, and repoint tls_* to them. After the state goes away, the | |
1467 | tls_* copies of the pointers remain valid and client delivery logging is happy. | |
1468 | ||
1469 | tls_certificate_verified is a BOOL, so the tls_peerdn and tls_cipher issues | |
1470 | don't apply. | |
1471 | ||
059ec3d9 | 1472 | Arguments: |
17c76198 | 1473 | state exim_gnutls_state_st * |
cf0c6164 | 1474 | errstr pointer to error string |
059ec3d9 | 1475 | |
17c76198 | 1476 | Returns: OK/DEFER/FAIL |
059ec3d9 PH |
1477 | */ |
1478 | ||
17c76198 | 1479 | static int |
cf0c6164 | 1480 | peer_status(exim_gnutls_state_st *state, uschar ** errstr) |
059ec3d9 | 1481 | { |
75fe387d | 1482 | uschar cipherbuf[256]; |
27f19eb4 | 1483 | const gnutls_datum_t *cert_list; |
75fe387d | 1484 | int old_pool, rc; |
17c76198 | 1485 | unsigned int cert_list_size = 0; |
4fe99a6c PP |
1486 | gnutls_protocol_t protocol; |
1487 | gnutls_cipher_algorithm_t cipher; | |
1488 | gnutls_kx_algorithm_t kx; | |
1489 | gnutls_mac_algorithm_t mac; | |
17c76198 PP |
1490 | gnutls_certificate_type_t ct; |
1491 | gnutls_x509_crt_t crt; | |
d7978c0f | 1492 | uschar *dn_buf; |
17c76198 | 1493 | size_t sz; |
059ec3d9 | 1494 | |
4fe99a6c | 1495 | if (state->have_set_peerdn) |
17c76198 | 1496 | return OK; |
4fe99a6c | 1497 | state->have_set_peerdn = TRUE; |
059ec3d9 | 1498 | |
4fe99a6c | 1499 | state->peerdn = NULL; |
059ec3d9 | 1500 | |
4fe99a6c PP |
1501 | /* tls_cipher */ |
1502 | cipher = gnutls_cipher_get(state->session); | |
1503 | protocol = gnutls_protocol_get_version(state->session); | |
1504 | mac = gnutls_mac_get(state->session); | |
1505 | kx = gnutls_kx_get(state->session); | |
1506 | ||
75fe387d | 1507 | string_format(cipherbuf, sizeof(cipherbuf), |
4fe99a6c PP |
1508 | "%s:%s:%d", |
1509 | gnutls_protocol_get_name(protocol), | |
1510 | gnutls_cipher_suite_get_name(kx, cipher, mac), | |
1511 | (int) gnutls_cipher_get_key_size(cipher) * 8); | |
1512 | ||
1513 | /* I don't see a way that spaces could occur, in the current GnuTLS | |
1514 | code base, but it was a concern in the old code and perhaps older GnuTLS | |
1515 | releases did return "TLS 1.0"; play it safe, just in case. */ | |
d7978c0f | 1516 | for (uschar * p = cipherbuf; *p != '\0'; ++p) |
4fe99a6c PP |
1517 | if (isspace(*p)) |
1518 | *p = '-'; | |
75fe387d PP |
1519 | old_pool = store_pool; |
1520 | store_pool = POOL_PERM; | |
1521 | state->ciphersuite = string_copy(cipherbuf); | |
1522 | store_pool = old_pool; | |
817d9f57 | 1523 | state->tlsp->cipher = state->ciphersuite; |
4fe99a6c PP |
1524 | |
1525 | /* tls_peerdn */ | |
17c76198 | 1526 | cert_list = gnutls_certificate_get_peers(state->session, &cert_list_size); |
83da1223 | 1527 | |
17c76198 PP |
1528 | if (cert_list == NULL || cert_list_size == 0) |
1529 | { | |
17c76198 PP |
1530 | DEBUG(D_tls) debug_printf("TLS: no certificate from peer (%p & %d)\n", |
1531 | cert_list, cert_list_size); | |
e51c7be2 | 1532 | if (state->verify_requirement >= VERIFY_REQUIRED) |
17c76198 | 1533 | return tls_error(US"certificate verification failed", |
48224640 | 1534 | US"no certificate received from peer", state->host, errstr); |
17c76198 PP |
1535 | return OK; |
1536 | } | |
059ec3d9 | 1537 | |
17c76198 PP |
1538 | ct = gnutls_certificate_type_get(state->session); |
1539 | if (ct != GNUTLS_CRT_X509) | |
059ec3d9 | 1540 | { |
48224640 | 1541 | const uschar *ctn = US gnutls_certificate_type_get_name(ct); |
17c76198 PP |
1542 | DEBUG(D_tls) |
1543 | debug_printf("TLS: peer cert not X.509 but instead \"%s\"\n", ctn); | |
e51c7be2 | 1544 | if (state->verify_requirement >= VERIFY_REQUIRED) |
17c76198 | 1545 | return tls_error(US"certificate verification not possible, unhandled type", |
cf0c6164 | 1546 | ctn, state->host, errstr); |
17c76198 | 1547 | return OK; |
83da1223 | 1548 | } |
059ec3d9 | 1549 | |
e51c7be2 JH |
1550 | #define exim_gnutls_peer_err(Label) \ |
1551 | do { \ | |
1552 | if (rc != GNUTLS_E_SUCCESS) \ | |
1553 | { \ | |
1554 | DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", \ | |
1555 | (Label), gnutls_strerror(rc)); \ | |
1556 | if (state->verify_requirement >= VERIFY_REQUIRED) \ | |
48224640 | 1557 | return tls_error((Label), US gnutls_strerror(rc), state->host, errstr); \ |
e51c7be2 JH |
1558 | return OK; \ |
1559 | } \ | |
1560 | } while (0) | |
17c76198 | 1561 | |
9d1c15ef JH |
1562 | rc = import_cert(&cert_list[0], &crt); |
1563 | exim_gnutls_peer_err(US"cert 0"); | |
1564 | ||
1565 | state->tlsp->peercert = state->peercert = crt; | |
17c76198 | 1566 | |
17c76198 PP |
1567 | sz = 0; |
1568 | rc = gnutls_x509_crt_get_dn(crt, NULL, &sz); | |
1569 | if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) | |
83da1223 | 1570 | { |
17c76198 PP |
1571 | exim_gnutls_peer_err(US"getting size for cert DN failed"); |
1572 | return FAIL; /* should not happen */ | |
059ec3d9 | 1573 | } |
17c76198 PP |
1574 | dn_buf = store_get_perm(sz); |
1575 | rc = gnutls_x509_crt_get_dn(crt, CS dn_buf, &sz); | |
1576 | exim_gnutls_peer_err(US"failed to extract certificate DN [gnutls_x509_crt_get_dn(cert 0)]"); | |
9d1c15ef | 1577 | |
17c76198 PP |
1578 | state->peerdn = dn_buf; |
1579 | ||
1580 | return OK; | |
1581 | #undef exim_gnutls_peer_err | |
1582 | } | |
059ec3d9 | 1583 | |
059ec3d9 | 1584 | |
059ec3d9 | 1585 | |
059ec3d9 | 1586 | |
17c76198 PP |
1587 | /************************************************* |
1588 | * Verify peer certificate * | |
1589 | *************************************************/ | |
059ec3d9 | 1590 | |
17c76198 PP |
1591 | /* Called from both server and client code. |
1592 | *Should* be using a callback registered with | |
1593 | gnutls_certificate_set_verify_function() to fail the handshake if we dislike | |
1594 | the peer information, but that's too new for some OSes. | |
059ec3d9 | 1595 | |
17c76198 | 1596 | Arguments: |
899b8bbc JH |
1597 | state exim_gnutls_state_st * |
1598 | errstr where to put an error message | |
059ec3d9 | 1599 | |
17c76198 PP |
1600 | Returns: |
1601 | FALSE if the session should be rejected | |
1602 | TRUE if the cert is okay or we just don't care | |
1603 | */ | |
059ec3d9 | 1604 | |
17c76198 | 1605 | static BOOL |
28646fa9 | 1606 | verify_certificate(exim_gnutls_state_st * state, uschar ** errstr) |
17c76198 PP |
1607 | { |
1608 | int rc; | |
899b8bbc JH |
1609 | uint verify; |
1610 | ||
1611 | if (state->verify_requirement == VERIFY_NONE) | |
1612 | return TRUE; | |
17c76198 | 1613 | |
8008accd | 1614 | DEBUG(D_tls) debug_printf("TLS: checking peer certificate\n"); |
cf0c6164 | 1615 | *errstr = NULL; |
17c76198 | 1616 | |
cf0c6164 | 1617 | if ((rc = peer_status(state, errstr)) != OK) |
e6060e2c | 1618 | { |
17c76198 | 1619 | verify = GNUTLS_CERT_INVALID; |
cf0c6164 | 1620 | *errstr = US"certificate not supplied"; |
17c76198 PP |
1621 | } |
1622 | else | |
899b8bbc JH |
1623 | |
1624 | { | |
1625 | #ifdef SUPPORT_DANE | |
1626 | if (state->verify_requirement == VERIFY_DANE && state->host) | |
1627 | { | |
1628 | /* Using dane_verify_session_crt() would be easy, as it does it all for us | |
1629 | including talking to a DNS resolver. But we want to do that bit ourselves | |
1630 | as the testsuite intercepts and fakes its own DNS environment. */ | |
1631 | ||
1632 | dane_state_t s; | |
1633 | dane_query_t r; | |
899b8bbc | 1634 | uint lsize; |
94c13285 JH |
1635 | const gnutls_datum_t * certlist = |
1636 | gnutls_certificate_get_peers(state->session, &lsize); | |
1637 | int usage = tls_out.tlsa_usage; | |
1638 | ||
1639 | # ifdef GNUTLS_BROKEN_DANE_VALIDATION | |
1640 | /* Split the TLSA records into two sets, TA and EE selectors. Run the | |
1641 | dane-verification separately so that we know which selector verified; | |
570cb1bd | 1642 | then we know whether to do name-verification (needed for TA but not EE). */ |
94c13285 JH |
1643 | |
1644 | if (usage == ((1<<DANESSL_USAGE_DANE_TA) | (1<<DANESSL_USAGE_DANE_EE))) | |
bd5b3f3c | 1645 | { /* a mixed-usage bundle */ |
94c13285 JH |
1646 | int i, j, nrec; |
1647 | const char ** dd; | |
1648 | int * ddl; | |
1649 | ||
1650 | for(nrec = 0; state->dane_data_len[nrec]; ) nrec++; | |
1651 | nrec++; | |
1652 | ||
1653 | dd = store_get(nrec * sizeof(uschar *)); | |
1654 | ddl = store_get(nrec * sizeof(int)); | |
1655 | nrec--; | |
1656 | ||
1657 | if ((rc = dane_state_init(&s, 0))) | |
1658 | goto tlsa_prob; | |
1659 | ||
1660 | for (usage = DANESSL_USAGE_DANE_EE; | |
1661 | usage >= DANESSL_USAGE_DANE_TA; usage--) | |
1662 | { /* take records with this usage */ | |
1663 | for (j = i = 0; i < nrec; i++) | |
1664 | if (state->dane_data[i][0] == usage) | |
1665 | { | |
1666 | dd[j] = state->dane_data[i]; | |
1667 | ddl[j++] = state->dane_data_len[i]; | |
1668 | } | |
1669 | if (j) | |
1670 | { | |
1671 | dd[j] = NULL; | |
1672 | ddl[j] = 0; | |
1673 | ||
1674 | if ((rc = dane_raw_tlsa(s, &r, (char * const *)dd, ddl, 1, 0))) | |
1675 | goto tlsa_prob; | |
1676 | ||
1677 | if ((rc = dane_verify_crt_raw(s, certlist, lsize, | |
1678 | gnutls_certificate_type_get(state->session), | |
1679 | r, 0, | |
1680 | usage == DANESSL_USAGE_DANE_EE | |
1681 | ? DANE_VFLAG_ONLY_CHECK_EE_USAGE : 0, | |
1682 | &verify))) | |
1683 | { | |
1684 | DEBUG(D_tls) | |
1685 | debug_printf("TLSA record problem: %s\n", dane_strerror(rc)); | |
1686 | } | |
1687 | else if (verify == 0) /* verification passed */ | |
1688 | { | |
1689 | usage = 1 << usage; | |
1690 | break; | |
1691 | } | |
1692 | } | |
1693 | } | |
899b8bbc | 1694 | |
94c13285 JH |
1695 | if (rc) goto tlsa_prob; |
1696 | } | |
1697 | else | |
1698 | # endif | |
899b8bbc | 1699 | { |
94c13285 JH |
1700 | if ( (rc = dane_state_init(&s, 0)) |
1701 | || (rc = dane_raw_tlsa(s, &r, state->dane_data, state->dane_data_len, | |
1702 | 1, 0)) | |
1703 | || (rc = dane_verify_crt_raw(s, certlist, lsize, | |
1704 | gnutls_certificate_type_get(state->session), | |
5ec37a55 | 1705 | r, 0, |
94c13285 JH |
1706 | # ifdef GNUTLS_BROKEN_DANE_VALIDATION |
1707 | usage == (1 << DANESSL_USAGE_DANE_EE) | |
1708 | ? DANE_VFLAG_ONLY_CHECK_EE_USAGE : 0, | |
1709 | # else | |
1710 | 0, | |
1711 | # endif | |
1712 | &verify)) | |
1713 | ) | |
1714 | goto tlsa_prob; | |
899b8bbc | 1715 | } |
94c13285 JH |
1716 | |
1717 | if (verify != 0) /* verification failed */ | |
899b8bbc JH |
1718 | { |
1719 | gnutls_datum_t str; | |
1720 | (void) dane_verification_status_print(verify, &str, 0); | |
1721 | *errstr = US str.data; /* don't bother to free */ | |
1722 | goto badcert; | |
1723 | } | |
28646fa9 | 1724 | |
94c13285 JH |
1725 | # ifdef GNUTLS_BROKEN_DANE_VALIDATION |
1726 | /* If a TA-mode TLSA record was used for verification we must additionally | |
570cb1bd | 1727 | verify the cert name (but not the CA chain). For EE-mode, skip it. */ |
28646fa9 | 1728 | |
94c13285 JH |
1729 | if (usage & (1 << DANESSL_USAGE_DANE_EE)) |
1730 | # endif | |
28646fa9 | 1731 | { |
570cb1bd | 1732 | state->peer_dane_verified = state->peer_cert_verified = TRUE; |
28646fa9 JH |
1733 | goto goodcert; |
1734 | } | |
570cb1bd JH |
1735 | # ifdef GNUTLS_BROKEN_DANE_VALIDATION |
1736 | /* Assume that the name on the A-record is the one that should be matching | |
1737 | the cert. An alternate view is that the domain part of the email address | |
1738 | is also permissible. */ | |
1739 | ||
1740 | if (gnutls_x509_crt_check_hostname(state->tlsp->peercert, | |
1741 | CS state->host->name)) | |
1742 | { | |
1743 | state->peer_dane_verified = state->peer_cert_verified = TRUE; | |
1744 | goto goodcert; | |
1745 | } | |
1746 | # endif | |
899b8bbc | 1747 | } |
570cb1bd | 1748 | #endif /*SUPPORT_DANE*/ |
899b8bbc | 1749 | |
17c76198 | 1750 | rc = gnutls_certificate_verify_peers2(state->session, &verify); |
899b8bbc | 1751 | } |
e6060e2c | 1752 | |
899b8bbc | 1753 | /* Handle the result of verification. INVALID is set if any others are. */ |
059ec3d9 | 1754 | |
28646fa9 | 1755 | if (rc < 0 || verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED)) |
17c76198 PP |
1756 | { |
1757 | state->peer_cert_verified = FALSE; | |
cf0c6164 | 1758 | if (!*errstr) |
184384c3 JH |
1759 | { |
1760 | #ifdef GNUTLS_CERT_VFY_STATUS_PRINT | |
1761 | DEBUG(D_tls) | |
1762 | { | |
1763 | gnutls_datum_t txt; | |
1764 | ||
1765 | if (gnutls_certificate_verification_status_print(verify, | |
1766 | gnutls_certificate_type_get(state->session), &txt, 0) | |
1767 | == GNUTLS_E_SUCCESS) | |
1768 | { | |
1769 | debug_printf("%s\n", txt.data); | |
1770 | gnutls_free(txt.data); | |
1771 | } | |
1772 | } | |
1773 | #endif | |
cf0c6164 JH |
1774 | *errstr = verify & GNUTLS_CERT_REVOKED |
1775 | ? US"certificate revoked" : US"certificate invalid"; | |
184384c3 | 1776 | } |
059ec3d9 | 1777 | |
17c76198 | 1778 | DEBUG(D_tls) |
e51c7be2 | 1779 | debug_printf("TLS certificate verification failed (%s): peerdn=\"%s\"\n", |
cf0c6164 | 1780 | *errstr, state->peerdn ? state->peerdn : US"<unset>"); |
059ec3d9 | 1781 | |
e51c7be2 | 1782 | if (state->verify_requirement >= VERIFY_REQUIRED) |
899b8bbc | 1783 | goto badcert; |
17c76198 | 1784 | DEBUG(D_tls) |
4789da3a | 1785 | debug_printf("TLS verify failure overridden (host in tls_try_verify_hosts)\n"); |
17c76198 | 1786 | } |
e51c7be2 | 1787 | |
17c76198 PP |
1788 | else |
1789 | { | |
5fd28bb8 JH |
1790 | /* Client side, check the server's certificate name versus the name on the |
1791 | A-record for the connection we made. What to do for server side - what name | |
1792 | to use for client? We document that there is no such checking for server | |
1793 | side. */ | |
1794 | ||
1795 | if ( state->exp_tls_verify_cert_hostnames | |
1796 | && !gnutls_x509_crt_check_hostname(state->tlsp->peercert, | |
1797 | CS state->exp_tls_verify_cert_hostnames) | |
1798 | ) | |
e51c7be2 | 1799 | { |
5fd28bb8 JH |
1800 | DEBUG(D_tls) |
1801 | debug_printf("TLS certificate verification failed: cert name mismatch\n"); | |
1802 | if (state->verify_requirement >= VERIFY_REQUIRED) | |
1803 | goto badcert; | |
1804 | return TRUE; | |
e51c7be2 | 1805 | } |
5fd28bb8 | 1806 | |
17c76198 | 1807 | state->peer_cert_verified = TRUE; |
e51c7be2 | 1808 | DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=\"%s\"\n", |
4fe99a6c | 1809 | state->peerdn ? state->peerdn : US"<unset>"); |
17c76198 | 1810 | } |
059ec3d9 | 1811 | |
28646fa9 JH |
1812 | goodcert: |
1813 | state->tlsp->peerdn = state->peerdn; | |
1814 | return TRUE; | |
899b8bbc | 1815 | |
b83314e3 | 1816 | #ifdef SUPPORT_DANE |
94c13285 | 1817 | tlsa_prob: |
624f33df JH |
1818 | *errstr = string_sprintf("TLSA record problem: %s", |
1819 | rc == DANE_E_REQUESTED_DATA_NOT_AVAILABLE ? "none usable" : dane_strerror(rc)); | |
b83314e3 JH |
1820 | #endif |
1821 | ||
899b8bbc JH |
1822 | badcert: |
1823 | gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); | |
1824 | return FALSE; | |
17c76198 | 1825 | } |
059ec3d9 | 1826 | |
17c76198 PP |
1827 | |
1828 | ||
1829 | ||
1830 | /* ------------------------------------------------------------------------ */ | |
1831 | /* Callbacks */ | |
1832 | ||
1833 | /* Logging function which can be registered with | |
1834 | * gnutls_global_set_log_function() | |
1835 | * gnutls_global_set_log_level() 0..9 | |
1836 | */ | |
af3498d6 | 1837 | #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 |
059ec3d9 | 1838 | static void |
17c76198 | 1839 | exim_gnutls_logger_cb(int level, const char *message) |
059ec3d9 | 1840 | { |
8c79eebf PP |
1841 | size_t len = strlen(message); |
1842 | if (len < 1) | |
1843 | { | |
1844 | DEBUG(D_tls) debug_printf("GnuTLS<%d> empty debug message\n", level); | |
1845 | return; | |
1846 | } | |
1847 | DEBUG(D_tls) debug_printf("GnuTLS<%d>: %s%s", level, message, | |
1848 | message[len-1] == '\n' ? "" : "\n"); | |
17c76198 | 1849 | } |
af3498d6 | 1850 | #endif |
059ec3d9 | 1851 | |
059ec3d9 | 1852 | |
17c76198 PP |
1853 | /* Called after client hello, should handle SNI work. |
1854 | This will always set tls_sni (state->received_sni) if available, | |
1855 | and may trigger presenting different certificates, | |
1856 | if state->trigger_sni_changes is TRUE. | |
059ec3d9 | 1857 | |
17c76198 PP |
1858 | Should be registered with |
1859 | gnutls_handshake_set_post_client_hello_function() | |
059ec3d9 | 1860 | |
17c76198 PP |
1861 | "This callback must return 0 on success or a gnutls error code to terminate the |
1862 | handshake.". | |
059ec3d9 | 1863 | |
17c76198 PP |
1864 | For inability to get SNI information, we return 0. |
1865 | We only return non-zero if re-setup failed. | |
817d9f57 | 1866 | Only used for server-side TLS. |
17c76198 | 1867 | */ |
44bbabb5 | 1868 | |
17c76198 PP |
1869 | static int |
1870 | exim_sni_handling_cb(gnutls_session_t session) | |
1871 | { | |
1872 | char sni_name[MAX_HOST_LEN]; | |
1873 | size_t data_len = MAX_HOST_LEN; | |
817d9f57 | 1874 | exim_gnutls_state_st *state = &state_server; |
17c76198 PP |
1875 | unsigned int sni_type; |
1876 | int rc, old_pool; | |
cf0c6164 | 1877 | uschar * dummy_errstr; |
17c76198 PP |
1878 | |
1879 | rc = gnutls_server_name_get(session, sni_name, &data_len, &sni_type, 0); | |
b34fc30c PP |
1880 | if (rc != GNUTLS_E_SUCCESS) |
1881 | { | |
1882 | DEBUG(D_tls) { | |
1883 | if (rc == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) | |
1884 | debug_printf("TLS: no SNI presented in handshake.\n"); | |
1885 | else | |
1886 | debug_printf("TLS failure: gnutls_server_name_get(): %s [%d]\n", | |
1887 | gnutls_strerror(rc), rc); | |
cf0c6164 | 1888 | } |
b34fc30c PP |
1889 | return 0; |
1890 | } | |
1891 | ||
17c76198 PP |
1892 | if (sni_type != GNUTLS_NAME_DNS) |
1893 | { | |
1894 | DEBUG(D_tls) debug_printf("TLS: ignoring SNI of unhandled type %u\n", sni_type); | |
1895 | return 0; | |
1896 | } | |
44bbabb5 | 1897 | |
17c76198 PP |
1898 | /* We now have a UTF-8 string in sni_name */ |
1899 | old_pool = store_pool; | |
1900 | store_pool = POOL_PERM; | |
1901 | state->received_sni = string_copyn(US sni_name, data_len); | |
1902 | store_pool = old_pool; | |
1903 | ||
1904 | /* We set this one now so that variable expansions below will work */ | |
817d9f57 | 1905 | state->tlsp->sni = state->received_sni; |
17c76198 PP |
1906 | |
1907 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", sni_name, | |
1908 | state->trigger_sni_changes ? "" : " (unused for certificate selection)"); | |
1909 | ||
1910 | if (!state->trigger_sni_changes) | |
1911 | return 0; | |
1912 | ||
cf0c6164 | 1913 | if ((rc = tls_expand_session_files(state, &dummy_errstr)) != OK) |
17c76198 PP |
1914 | { |
1915 | /* If the setup of certs/etc failed before handshake, TLS would not have | |
1916 | been offered. The best we can do now is abort. */ | |
1917 | return GNUTLS_E_APPLICATION_ERROR_MIN; | |
1918 | } | |
1919 | ||
cf0c6164 | 1920 | rc = tls_set_remaining_x509(state, &dummy_errstr); |
1365611d PP |
1921 | if (rc != OK) return GNUTLS_E_APPLICATION_ERROR_MIN; |
1922 | ||
1923 | return 0; | |
059ec3d9 PH |
1924 | } |
1925 | ||
1926 | ||
1927 | ||
f2de3a33 | 1928 | #ifndef DISABLE_OCSP |
44662487 JH |
1929 | |
1930 | static int | |
1931 | server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, | |
1932 | gnutls_datum_t * ocsp_response) | |
1933 | { | |
1934 | int ret; | |
47195144 | 1935 | DEBUG(D_tls) debug_printf("OCSP stapling callback: %s\n", US ptr); |
44662487 | 1936 | |
44662487 JH |
1937 | if ((ret = gnutls_load_file(ptr, ocsp_response)) < 0) |
1938 | { | |
1939 | DEBUG(D_tls) debug_printf("Failed to load ocsp stapling file %s\n", | |
5903c6ff | 1940 | CS ptr); |
018058b2 | 1941 | tls_in.ocsp = OCSP_NOT_RESP; |
44662487 JH |
1942 | return GNUTLS_E_NO_CERTIFICATE_STATUS; |
1943 | } | |
1944 | ||
018058b2 | 1945 | tls_in.ocsp = OCSP_VFY_NOT_TRIED; |
44662487 JH |
1946 | return 0; |
1947 | } | |
1948 | ||
1949 | #endif | |
1950 | ||
1951 | ||
0cbf2b82 | 1952 | #ifndef DISABLE_EVENT |
a7538db1 JH |
1953 | /* |
1954 | We use this callback to get observability and detail-level control | |
723fe533 JH |
1955 | for an exim TLS connection (either direction), raising a tls:cert event |
1956 | for each cert in the chain presented by the peer. Any event | |
a7538db1 JH |
1957 | can deny verification. |
1958 | ||
1959 | Return 0 for the handshake to continue or non-zero to terminate. | |
1960 | */ | |
1961 | ||
1962 | static int | |
723fe533 | 1963 | verify_cb(gnutls_session_t session) |
a7538db1 | 1964 | { |
27f19eb4 | 1965 | const gnutls_datum_t * cert_list; |
a7538db1 JH |
1966 | unsigned int cert_list_size = 0; |
1967 | gnutls_x509_crt_t crt; | |
1968 | int rc; | |
b30275b8 | 1969 | uschar * yield; |
a7538db1 JH |
1970 | exim_gnutls_state_st * state = gnutls_session_get_ptr(session); |
1971 | ||
bd5b3f3c | 1972 | if ((cert_list = gnutls_certificate_get_peers(session, &cert_list_size))) |
a7538db1 JH |
1973 | while (cert_list_size--) |
1974 | { | |
bd5b3f3c | 1975 | if ((rc = import_cert(&cert_list[cert_list_size], &crt)) != GNUTLS_E_SUCCESS) |
a7538db1 JH |
1976 | { |
1977 | DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n", | |
1978 | cert_list_size, gnutls_strerror(rc)); | |
1979 | break; | |
1980 | } | |
1981 | ||
1982 | state->tlsp->peercert = crt; | |
b30275b8 JH |
1983 | if ((yield = event_raise(state->event_action, |
1984 | US"tls:cert", string_sprintf("%d", cert_list_size)))) | |
a7538db1 JH |
1985 | { |
1986 | log_write(0, LOG_MAIN, | |
b30275b8 JH |
1987 | "SSL verify denied by event-action: depth=%d: %s", |
1988 | cert_list_size, yield); | |
a7538db1 JH |
1989 | return 1; /* reject */ |
1990 | } | |
1991 | state->tlsp->peercert = NULL; | |
1992 | } | |
1993 | ||
1994 | return 0; | |
1995 | } | |
1996 | ||
1997 | #endif | |
44662487 JH |
1998 | |
1999 | ||
f20cfa4a JH |
2000 | static gstring * |
2001 | ddump(gnutls_datum_t * d) | |
2002 | { | |
2003 | gstring * g = string_get((d->size+1) * 2); | |
2004 | uschar * s = d->data; | |
2005 | for (unsigned i = d->size; i > 0; i--, s++) | |
2006 | { | |
2007 | g = string_catn(g, US "0123456789abcdef" + (*s >> 4), 1); | |
2008 | g = string_catn(g, US "0123456789abcdef" + (*s & 0xf), 1); | |
2009 | } | |
2010 | return g; | |
2011 | } | |
17c76198 PP |
2012 | |
2013 | /* ------------------------------------------------------------------------ */ | |
2014 | /* Exported functions */ | |
2015 | ||
2016 | ||
2017 | ||
2018 | ||
059ec3d9 PH |
2019 | /************************************************* |
2020 | * Start a TLS session in a server * | |
2021 | *************************************************/ | |
2022 | ||
2023 | /* This is called when Exim is running as a server, after having received | |
2024 | the STARTTLS command. It must respond to that command, and then negotiate | |
2025 | a TLS session. | |
2026 | ||
2027 | Arguments: | |
83da1223 | 2028 | require_ciphers list of allowed ciphers or NULL |
cf0c6164 | 2029 | errstr pointer to error string |
059ec3d9 PH |
2030 | |
2031 | Returns: OK on success | |
2032 | DEFER for errors before the start of the negotiation | |
4c04137d | 2033 | FAIL for errors during the negotiation; the server can't |
059ec3d9 PH |
2034 | continue running. |
2035 | */ | |
2036 | ||
2037 | int | |
cf0c6164 | 2038 | tls_server_start(const uschar * require_ciphers, uschar ** errstr) |
059ec3d9 PH |
2039 | { |
2040 | int rc; | |
cf0c6164 | 2041 | exim_gnutls_state_st * state = NULL; |
059ec3d9 PH |
2042 | |
2043 | /* Check for previous activation */ | |
74f1a423 | 2044 | if (tls_in.active.sock >= 0) |
059ec3d9 | 2045 | { |
48224640 | 2046 | tls_error(US"STARTTLS received after TLS started", US "", NULL, errstr); |
925ac8e4 | 2047 | smtp_printf("554 Already in TLS\r\n", FALSE); |
059ec3d9 PH |
2048 | return FAIL; |
2049 | } | |
2050 | ||
2051 | /* Initialize the library. If it fails, it will already have logged the error | |
2052 | and sent an SMTP response. */ | |
2053 | ||
17c76198 | 2054 | DEBUG(D_tls) debug_printf("initialising GnuTLS as a server\n"); |
059ec3d9 | 2055 | |
cf0c6164 | 2056 | if ((rc = tls_init(NULL, tls_certificate, tls_privatekey, |
17c76198 | 2057 | NULL, tls_verify_certificates, tls_crl, |
74f1a423 | 2058 | require_ciphers, &state, &tls_in, errstr)) != OK) return rc; |
059ec3d9 | 2059 | |
059ec3d9 PH |
2060 | /* If this is a host for which certificate verification is mandatory or |
2061 | optional, set up appropriately. */ | |
2062 | ||
059ec3d9 | 2063 | if (verify_check_host(&tls_verify_hosts) == OK) |
17c76198 | 2064 | { |
e51c7be2 JH |
2065 | DEBUG(D_tls) |
2066 | debug_printf("TLS: a client certificate will be required.\n"); | |
17c76198 PP |
2067 | state->verify_requirement = VERIFY_REQUIRED; |
2068 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); | |
2069 | } | |
059ec3d9 | 2070 | else if (verify_check_host(&tls_try_verify_hosts) == OK) |
17c76198 | 2071 | { |
e51c7be2 JH |
2072 | DEBUG(D_tls) |
2073 | debug_printf("TLS: a client certificate will be requested but not required.\n"); | |
17c76198 PP |
2074 | state->verify_requirement = VERIFY_OPTIONAL; |
2075 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST); | |
2076 | } | |
2077 | else | |
2078 | { | |
e51c7be2 JH |
2079 | DEBUG(D_tls) |
2080 | debug_printf("TLS: a client certificate will not be requested.\n"); | |
17c76198 PP |
2081 | state->verify_requirement = VERIFY_NONE; |
2082 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); | |
2083 | } | |
059ec3d9 | 2084 | |
0cbf2b82 | 2085 | #ifndef DISABLE_EVENT |
723fe533 JH |
2086 | if (event_action) |
2087 | { | |
2088 | state->event_action = event_action; | |
2089 | gnutls_session_set_ptr(state->session, state); | |
2090 | gnutls_certificate_set_verify_function(state->x509_cred, verify_cb); | |
2091 | } | |
2092 | #endif | |
2093 | ||
17c76198 PP |
2094 | /* Register SNI handling; always, even if not in tls_certificate, so that the |
2095 | expansion variable $tls_sni is always available. */ | |
059ec3d9 | 2096 | |
17c76198 PP |
2097 | gnutls_handshake_set_post_client_hello_function(state->session, |
2098 | exim_sni_handling_cb); | |
059ec3d9 PH |
2099 | |
2100 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
2101 | on connection, where outputting anything now upsets the clients and tends to | |
2102 | make them disconnect. We need to have an explicit fflush() here, to force out | |
2103 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
2104 | mode, the fflush() happens when smtp_getc() is called. */ | |
2105 | ||
817d9f57 | 2106 | if (!state->tlsp->on_connect) |
059ec3d9 | 2107 | { |
925ac8e4 | 2108 | smtp_printf("220 TLS go ahead\r\n", FALSE); |
9d1c15ef | 2109 | fflush(smtp_out); |
059ec3d9 PH |
2110 | } |
2111 | ||
2112 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
8008accd JH |
2113 | that the GnuTLS library doesn't. |
2114 | From 3.1.0 there is gnutls_handshake_set_timeout() - but it requires you | |
2115 | to set (and clear down afterwards) up a pull-timeout callback function that does | |
2116 | a select, so we're no better off unless avoiding signals becomes an issue. */ | |
059ec3d9 | 2117 | |
17c76198 | 2118 | gnutls_transport_set_ptr2(state->session, |
27f19eb4 JH |
2119 | (gnutls_transport_ptr_t)(long) fileno(smtp_in), |
2120 | (gnutls_transport_ptr_t)(long) fileno(smtp_out)); | |
17c76198 PP |
2121 | state->fd_in = fileno(smtp_in); |
2122 | state->fd_out = fileno(smtp_out); | |
059ec3d9 PH |
2123 | |
2124 | sigalrm_seen = FALSE; | |
c2a1bba0 | 2125 | if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); |
17c76198 | 2126 | do |
17c76198 | 2127 | rc = gnutls_handshake(state->session); |
157a7880 | 2128 | while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen); |
c2a1bba0 | 2129 | ALARM_CLR(0); |
059ec3d9 | 2130 | |
17c76198 | 2131 | if (rc != GNUTLS_E_SUCCESS) |
059ec3d9 | 2132 | { |
059ec3d9 PH |
2133 | /* It seems that, except in the case of a timeout, we have to close the |
2134 | connection right here; otherwise if the other end is running OpenSSL it hangs | |
2135 | until the server times out. */ | |
2136 | ||
60d10ce7 | 2137 | if (sigalrm_seen) |
ad7fc6eb | 2138 | { |
48224640 | 2139 | tls_error(US"gnutls_handshake", US"timed out", NULL, errstr); |
ad7fc6eb JH |
2140 | gnutls_db_remove_session(state->session); |
2141 | } | |
60d10ce7 | 2142 | else |
059ec3d9 | 2143 | { |
48224640 | 2144 | tls_error(US"gnutls_handshake", US gnutls_strerror(rc), NULL, errstr); |
f5d25c2b | 2145 | (void) gnutls_alert_send_appropriate(state->session, rc); |
ad7fc6eb | 2146 | gnutls_deinit(state->session); |
ed62aae3 | 2147 | gnutls_certificate_free_credentials(state->x509_cred); |
60d10ce7 | 2148 | millisleep(500); |
ad7fc6eb | 2149 | shutdown(state->fd_out, SHUT_WR); |
d7978c0f | 2150 | for (int i = 1024; fgetc(smtp_in) != EOF && i > 0; ) i--; /* drain skt */ |
f1e894f3 PH |
2151 | (void)fclose(smtp_out); |
2152 | (void)fclose(smtp_in); | |
60d10ce7 | 2153 | smtp_out = smtp_in = NULL; |
059ec3d9 PH |
2154 | } |
2155 | ||
2156 | return FAIL; | |
2157 | } | |
2158 | ||
f20cfa4a JH |
2159 | DEBUG(D_tls) |
2160 | { | |
2161 | debug_printf("gnutls_handshake was successful\n"); | |
2162 | #ifdef SUPPORT_GNUTLS_SESS_DESC | |
2163 | debug_printf("%s\n", gnutls_session_get_desc(state->session)); | |
2164 | #endif | |
2165 | #ifdef SUPPORT_GNUTLS_KEYLOG | |
2166 | { | |
2167 | gnutls_datum_t c, s; | |
2168 | gstring * gc, * gs; | |
2169 | gnutls_session_get_random(state->session, &c, &s); | |
2170 | gnutls_session_get_master_secret(state->session, &s); | |
2171 | gc = ddump(&c); | |
2172 | gs = ddump(&s); | |
2173 | debug_printf("CLIENT_RANDOM %.*s %.*s\n", (int)gc->ptr, gc->s, (int)gs->ptr, gs->s); | |
2174 | } | |
2175 | #endif | |
2176 | } | |
059ec3d9 | 2177 | |
17c76198 PP |
2178 | /* Verify after the fact */ |
2179 | ||
899b8bbc | 2180 | if (!verify_certificate(state, errstr)) |
059ec3d9 | 2181 | { |
9d1c15ef | 2182 | if (state->verify_requirement != VERIFY_OPTIONAL) |
17c76198 | 2183 | { |
cf0c6164 | 2184 | (void) tls_error(US"certificate verification failed", *errstr, NULL, errstr); |
9d1c15ef | 2185 | return FAIL; |
17c76198 | 2186 | } |
9d1c15ef JH |
2187 | DEBUG(D_tls) |
2188 | debug_printf("TLS: continuing on only because verification was optional, after: %s\n", | |
cf0c6164 | 2189 | *errstr); |
059ec3d9 PH |
2190 | } |
2191 | ||
17c76198 PP |
2192 | /* Figure out peer DN, and if authenticated, etc. */ |
2193 | ||
cf0c6164 | 2194 | if ((rc = peer_status(state, NULL)) != OK) return rc; |
17c76198 PP |
2195 | |
2196 | /* Sets various Exim expansion variables; always safe within server */ | |
2197 | ||
9d1c15ef | 2198 | extract_exim_vars_from_tls_state(state); |
059ec3d9 PH |
2199 | |
2200 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
2201 | and initialize appropriately. */ | |
2202 | ||
17c76198 | 2203 | state->xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
059ec3d9 PH |
2204 | |
2205 | receive_getc = tls_getc; | |
0d81dabc | 2206 | receive_getbuf = tls_getbuf; |
584e96c6 | 2207 | receive_get_cache = tls_get_cache; |
059ec3d9 PH |
2208 | receive_ungetc = tls_ungetc; |
2209 | receive_feof = tls_feof; | |
2210 | receive_ferror = tls_ferror; | |
58eb016e | 2211 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 2212 | |
059ec3d9 PH |
2213 | return OK; |
2214 | } | |
2215 | ||
2216 | ||
2217 | ||
2218 | ||
aa2a70ba JH |
2219 | static void |
2220 | tls_client_setup_hostname_checks(host_item * host, exim_gnutls_state_st * state, | |
2221 | smtp_transport_options_block * ob) | |
2222 | { | |
3fb3231c | 2223 | if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK) |
aa2a70ba | 2224 | { |
4af0d74a | 2225 | state->exp_tls_verify_cert_hostnames = |
8c5d388a | 2226 | #ifdef SUPPORT_I18N |
4af0d74a JH |
2227 | string_domain_utf8_to_alabel(host->name, NULL); |
2228 | #else | |
2229 | host->name; | |
2230 | #endif | |
aa2a70ba JH |
2231 | DEBUG(D_tls) |
2232 | debug_printf("TLS: server cert verification includes hostname: \"%s\".\n", | |
2233 | state->exp_tls_verify_cert_hostnames); | |
2234 | } | |
2235 | } | |
aa2a70ba JH |
2236 | |
2237 | ||
899b8bbc JH |
2238 | |
2239 | ||
2240 | #ifdef SUPPORT_DANE | |
2241 | /* Given our list of RRs from the TLSA lookup, build a lookup block in | |
2242 | GnuTLS-DANE's preferred format. Hang it on the state str for later | |
2243 | use in DANE verification. | |
2244 | ||
2245 | We point at the dnsa data not copy it, so it must remain valid until | |
2246 | after verification is done.*/ | |
2247 | ||
3674140c | 2248 | static BOOL |
899b8bbc JH |
2249 | dane_tlsa_load(exim_gnutls_state_st * state, dns_answer * dnsa) |
2250 | { | |
899b8bbc JH |
2251 | dns_scan dnss; |
2252 | int i; | |
2253 | const char ** dane_data; | |
2254 | int * dane_data_len; | |
2255 | ||
d7978c0f JH |
2256 | i = 1; |
2257 | for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; | |
899b8bbc JH |
2258 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) |
2259 | ) if (rr->type == T_TLSA) i++; | |
2260 | ||
2261 | dane_data = store_get(i * sizeof(uschar *)); | |
2262 | dane_data_len = store_get(i * sizeof(int)); | |
2263 | ||
d7978c0f JH |
2264 | i = 0; |
2265 | for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; | |
899b8bbc | 2266 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) |
1b76ad22 | 2267 | ) if (rr->type == T_TLSA && rr->size > 3) |
899b8bbc JH |
2268 | { |
2269 | const uschar * p = rr->data; | |
3674140c JH |
2270 | uint8_t usage = p[0], sel = p[1], type = p[2]; |
2271 | ||
2272 | DEBUG(D_tls) | |
2273 | debug_printf("TLSA: %d %d %d size %d\n", usage, sel, type, rr->size); | |
2274 | ||
94c13285 JH |
2275 | if ( (usage != DANESSL_USAGE_DANE_TA && usage != DANESSL_USAGE_DANE_EE) |
2276 | || (sel != 0 && sel != 1) | |
2277 | ) | |
2278 | continue; | |
3674140c JH |
2279 | switch(type) |
2280 | { | |
2281 | case 0: /* Full: cannot check at present */ | |
2282 | break; | |
2283 | case 1: if (rr->size != 3 + 256/8) continue; /* sha2-256 */ | |
2284 | break; | |
2285 | case 2: if (rr->size != 3 + 512/8) continue; /* sha2-512 */ | |
2286 | break; | |
2287 | default: continue; | |
2288 | } | |
899b8bbc JH |
2289 | |
2290 | tls_out.tlsa_usage |= 1<<usage; | |
48224640 | 2291 | dane_data[i] = CS p; |
899b8bbc JH |
2292 | dane_data_len[i++] = rr->size; |
2293 | } | |
3674140c JH |
2294 | |
2295 | if (!i) return FALSE; | |
2296 | ||
899b8bbc JH |
2297 | dane_data[i] = NULL; |
2298 | dane_data_len[i] = 0; | |
2299 | ||
2300 | state->dane_data = (char * const *)dane_data; | |
2301 | state->dane_data_len = dane_data_len; | |
3674140c | 2302 | return TRUE; |
899b8bbc JH |
2303 | } |
2304 | #endif | |
2305 | ||
2306 | ||
2307 | ||
059ec3d9 PH |
2308 | /************************************************* |
2309 | * Start a TLS session in a client * | |
2310 | *************************************************/ | |
2311 | ||
2312 | /* Called from the smtp transport after STARTTLS has been accepted. | |
2313 | ||
2314 | Arguments: | |
2315 | fd the fd of the connection | |
afdb5e9c | 2316 | host connected host (for messages and option-tests) |
83da1223 | 2317 | addr the first address (not used) |
a7538db1 | 2318 | tb transport (always smtp) |
899b8bbc JH |
2319 | tlsa_dnsa non-NULL, either request or require dane for this host, and |
2320 | a TLSA record found. Therefore, dane verify required. | |
2321 | Which implies cert must be requested and supplied, dane | |
2322 | verify must pass, and cert verify irrelevant (incl. | |
2323 | hostnames), and (caller handled) require_tls | |
74f1a423 | 2324 | tlsp record details of channel configuration |
cf0c6164 JH |
2325 | errstr error string pointer |
2326 | ||
74f1a423 | 2327 | Returns: Pointer to TLS session context, or NULL on error |
059ec3d9 PH |
2328 | */ |
2329 | ||
74f1a423 | 2330 | void * |
17c76198 | 2331 | tls_client_start(int fd, host_item *host, |
f5d78688 | 2332 | address_item *addr ARG_UNUSED, |
cf0c6164 | 2333 | transport_instance * tb, |
c0635b6d | 2334 | #ifdef SUPPORT_DANE |
899b8bbc | 2335 | dns_answer * tlsa_dnsa, |
0e66b3b6 | 2336 | #endif |
74f1a423 | 2337 | tls_support * tlsp, uschar ** errstr) |
059ec3d9 | 2338 | { |
afdb5e9c JH |
2339 | smtp_transport_options_block *ob = tb |
2340 | ? (smtp_transport_options_block *)tb->options_block | |
2341 | : &smtp_transport_option_defaults; | |
059ec3d9 | 2342 | int rc; |
899b8bbc | 2343 | exim_gnutls_state_st * state = NULL; |
5ec37a55 | 2344 | uschar *cipher_list = NULL; |
74f1a423 | 2345 | |
f2de3a33 | 2346 | #ifndef DISABLE_OCSP |
5130845b | 2347 | BOOL require_ocsp = |
3fb3231c | 2348 | verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK; |
44662487 | 2349 | BOOL request_ocsp = require_ocsp ? TRUE |
3fb3231c | 2350 | : verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK; |
2b4a568d | 2351 | #endif |
059ec3d9 | 2352 | |
17c76198 | 2353 | DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", fd); |
059ec3d9 | 2354 | |
5ec37a55 | 2355 | #ifdef SUPPORT_DANE |
cf260049 | 2356 | if (tlsa_dnsa && ob->dane_require_tls_ciphers) |
5ec37a55 PP |
2357 | { |
2358 | /* not using expand_check_tlsvar because not yet in state */ | |
2359 | if (!expand_check(ob->dane_require_tls_ciphers, US"dane_require_tls_ciphers", | |
2360 | &cipher_list, errstr)) | |
74f1a423 | 2361 | return NULL; |
cf260049 JH |
2362 | cipher_list = cipher_list && *cipher_list |
2363 | ? ob->dane_require_tls_ciphers : ob->tls_require_ciphers; | |
5ec37a55 PP |
2364 | } |
2365 | #endif | |
2366 | ||
2367 | if (!cipher_list) | |
2368 | cipher_list = ob->tls_require_ciphers; | |
2369 | ||
74f1a423 | 2370 | if (tls_init(host, ob->tls_certificate, ob->tls_privatekey, |
65867078 | 2371 | ob->tls_sni, ob->tls_verify_certificates, ob->tls_crl, |
74f1a423 JH |
2372 | cipher_list, &state, tlsp, errstr) != OK) |
2373 | return NULL; | |
059ec3d9 | 2374 | |
54c90be1 | 2375 | { |
65867078 JH |
2376 | int dh_min_bits = ob->tls_dh_min_bits; |
2377 | if (dh_min_bits < EXIM_CLIENT_DH_MIN_MIN_BITS) | |
2378 | { | |
2379 | DEBUG(D_tls) | |
2380 | debug_printf("WARNING: tls_dh_min_bits far too low," | |
2381 | " clamping %d up to %d\n", | |
2382 | dh_min_bits, EXIM_CLIENT_DH_MIN_MIN_BITS); | |
2383 | dh_min_bits = EXIM_CLIENT_DH_MIN_MIN_BITS; | |
2384 | } | |
54c90be1 | 2385 | |
65867078 JH |
2386 | DEBUG(D_tls) debug_printf("Setting D-H prime minimum" |
2387 | " acceptable bits to %d\n", | |
2388 | dh_min_bits); | |
2389 | gnutls_dh_set_prime_bits(state->session, dh_min_bits); | |
2390 | } | |
83da1223 | 2391 | |
94431adb | 2392 | /* Stick to the old behaviour for compatibility if tls_verify_certificates is |
2b4a568d JH |
2393 | set but both tls_verify_hosts and tls_try_verify_hosts are unset. Check only |
2394 | the specified host patterns if one of them is defined */ | |
2395 | ||
899b8bbc | 2396 | #ifdef SUPPORT_DANE |
3674140c | 2397 | if (tlsa_dnsa && dane_tlsa_load(state, tlsa_dnsa)) |
899b8bbc JH |
2398 | { |
2399 | DEBUG(D_tls) | |
2400 | debug_printf("TLS: server certificate DANE required.\n"); | |
2401 | state->verify_requirement = VERIFY_DANE; | |
2402 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); | |
899b8bbc JH |
2403 | } |
2404 | else | |
2405 | #endif | |
2406 | if ( ( state->exp_tls_verify_certificates | |
2407 | && !ob->tls_verify_hosts | |
2408 | && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) | |
2409 | ) | |
3fb3231c | 2410 | || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK |
899b8bbc | 2411 | ) |
17c76198 | 2412 | { |
aa2a70ba | 2413 | tls_client_setup_hostname_checks(host, state, ob); |
aa2a70ba JH |
2414 | DEBUG(D_tls) |
2415 | debug_printf("TLS: server certificate verification required.\n"); | |
2416 | state->verify_requirement = VERIFY_REQUIRED; | |
52f93eed WB |
2417 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); |
2418 | } | |
3fb3231c | 2419 | else if (verify_check_given_host(CUSS &ob->tls_try_verify_hosts, host) == OK) |
52f93eed | 2420 | { |
aa2a70ba | 2421 | tls_client_setup_hostname_checks(host, state, ob); |
e51c7be2 JH |
2422 | DEBUG(D_tls) |
2423 | debug_printf("TLS: server certificate verification optional.\n"); | |
52f93eed | 2424 | state->verify_requirement = VERIFY_OPTIONAL; |
17c76198 PP |
2425 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST); |
2426 | } | |
2427 | else | |
2428 | { | |
e51c7be2 JH |
2429 | DEBUG(D_tls) |
2430 | debug_printf("TLS: server certificate verification not required.\n"); | |
52f93eed WB |
2431 | state->verify_requirement = VERIFY_NONE; |
2432 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); | |
17c76198 | 2433 | } |
059ec3d9 | 2434 | |
f2de3a33 JH |
2435 | #ifndef DISABLE_OCSP |
2436 | /* supported since GnuTLS 3.1.3 */ | |
44662487 | 2437 | if (request_ocsp) |
9d1c15ef JH |
2438 | { |
2439 | DEBUG(D_tls) debug_printf("TLS: will request OCSP stapling\n"); | |
65867078 JH |
2440 | if ((rc = gnutls_ocsp_status_request_enable_client(state->session, |
2441 | NULL, 0, NULL)) != OK) | |
74f1a423 | 2442 | { |
48224640 | 2443 | tls_error(US"cert-status-req", US gnutls_strerror(rc), state->host, errstr); |
74f1a423 JH |
2444 | return NULL; |
2445 | } | |
2446 | tlsp->ocsp = OCSP_NOT_RESP; | |
9d1c15ef | 2447 | } |
2b4a568d JH |
2448 | #endif |
2449 | ||
0cbf2b82 | 2450 | #ifndef DISABLE_EVENT |
afdb5e9c | 2451 | if (tb && tb->event_action) |
a7538db1 | 2452 | { |
774ef2d7 | 2453 | state->event_action = tb->event_action; |
a7538db1 | 2454 | gnutls_session_set_ptr(state->session, state); |
723fe533 | 2455 | gnutls_certificate_set_verify_function(state->x509_cred, verify_cb); |
a7538db1 JH |
2456 | } |
2457 | #endif | |
2458 | ||
27f19eb4 | 2459 | gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr_t)(long) fd); |
17c76198 PP |
2460 | state->fd_in = fd; |
2461 | state->fd_out = fd; | |
059ec3d9 | 2462 | |
9d1c15ef | 2463 | DEBUG(D_tls) debug_printf("about to gnutls_handshake\n"); |
059ec3d9 PH |
2464 | /* There doesn't seem to be a built-in timeout on connection. */ |
2465 | ||
2466 | sigalrm_seen = FALSE; | |
c2a1bba0 | 2467 | ALARM(ob->command_timeout); |
17c76198 | 2468 | do |
17c76198 | 2469 | rc = gnutls_handshake(state->session); |
f1fed05b | 2470 | while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen); |
c2a1bba0 | 2471 | ALARM_CLR(0); |
059ec3d9 | 2472 | |
4fe99a6c | 2473 | if (rc != GNUTLS_E_SUCCESS) |
74f1a423 | 2474 | { |
60d10ce7 JH |
2475 | if (sigalrm_seen) |
2476 | { | |
2477 | gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_USER_CANCELED); | |
48224640 | 2478 | tls_error(US"gnutls_handshake", US"timed out", state->host, errstr); |
60d10ce7 JH |
2479 | } |
2480 | else | |
48224640 | 2481 | tls_error(US"gnutls_handshake", US gnutls_strerror(rc), state->host, errstr); |
74f1a423 JH |
2482 | return NULL; |
2483 | } | |
4fe99a6c | 2484 | |
f20cfa4a JH |
2485 | DEBUG(D_tls) |
2486 | { | |
2487 | debug_printf("gnutls_handshake was successful\n"); | |
2488 | #ifdef SUPPORT_GNUTLS_SESS_DESC | |
2489 | debug_printf("%s\n", gnutls_session_get_desc(state->session)); | |
2490 | #endif | |
2491 | #ifdef SUPPORT_GNUTLS_KEYLOG | |
2492 | { | |
2493 | gnutls_datum_t c, s; | |
2494 | gstring * gc, * gs; | |
2495 | gnutls_session_get_random(state->session, &c, &s); | |
2496 | gnutls_session_get_master_secret(state->session, &s); | |
2497 | gc = ddump(&c); | |
2498 | gs = ddump(&s); | |
2499 | debug_printf("CLIENT_RANDOM %.*s %.*s\n", (int)gc->ptr, gc->s, (int)gs->ptr, gs->s); | |
2500 | } | |
2501 | #endif | |
2502 | } | |
059ec3d9 | 2503 | |
17c76198 | 2504 | /* Verify late */ |
059ec3d9 | 2505 | |
899b8bbc | 2506 | if (!verify_certificate(state, errstr)) |
74f1a423 JH |
2507 | { |
2508 | tls_error(US"certificate verification failed", *errstr, state->host, errstr); | |
2509 | return NULL; | |
2510 | } | |
059ec3d9 | 2511 | |
f2de3a33 | 2512 | #ifndef DISABLE_OCSP |
2b4a568d JH |
2513 | if (require_ocsp) |
2514 | { | |
2515 | DEBUG(D_tls) | |
2516 | { | |
2517 | gnutls_datum_t stapling; | |
2518 | gnutls_ocsp_resp_t resp; | |
2519 | gnutls_datum_t printed; | |
2520 | if ( (rc= gnutls_ocsp_status_request_get(state->session, &stapling)) == 0 | |
2521 | && (rc= gnutls_ocsp_resp_init(&resp)) == 0 | |
2522 | && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0 | |
2523 | && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_FULL, &printed)) == 0 | |
2524 | ) | |
2525 | { | |
65867078 | 2526 | debug_printf("%.4096s", printed.data); |
2b4a568d JH |
2527 | gnutls_free(printed.data); |
2528 | } | |
2529 | else | |
48224640 | 2530 | (void) tls_error(US"ocsp decode", US gnutls_strerror(rc), state->host, errstr); |
2b4a568d JH |
2531 | } |
2532 | ||
2b4a568d | 2533 | if (gnutls_ocsp_status_request_is_checked(state->session, 0) == 0) |
018058b2 | 2534 | { |
74f1a423 JH |
2535 | tlsp->ocsp = OCSP_FAILED; |
2536 | tls_error(US"certificate status check failed", NULL, state->host, errstr); | |
2537 | return NULL; | |
018058b2 | 2538 | } |
2b4a568d | 2539 | DEBUG(D_tls) debug_printf("Passed OCSP checking\n"); |
74f1a423 | 2540 | tlsp->ocsp = OCSP_VFIED; |
2b4a568d JH |
2541 | } |
2542 | #endif | |
2543 | ||
17c76198 | 2544 | /* Figure out peer DN, and if authenticated, etc. */ |
059ec3d9 | 2545 | |
74f1a423 JH |
2546 | if (peer_status(state, errstr) != OK) |
2547 | return NULL; | |
059ec3d9 | 2548 | |
4fe99a6c | 2549 | /* Sets various Exim expansion variables; may need to adjust for ACL callouts */ |
059ec3d9 | 2550 | |
9d1c15ef | 2551 | extract_exim_vars_from_tls_state(state); |
059ec3d9 | 2552 | |
74f1a423 | 2553 | return state; |
059ec3d9 PH |
2554 | } |
2555 | ||
2556 | ||
2557 | ||
17c76198 | 2558 | |
059ec3d9 | 2559 | /************************************************* |
17c76198 | 2560 | * Close down a TLS session * |
059ec3d9 PH |
2561 | *************************************************/ |
2562 | ||
17c76198 PP |
2563 | /* This is also called from within a delivery subprocess forked from the |
2564 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
2565 | would tamper with the TLS session in the parent process). | |
059ec3d9 | 2566 | |
dec766a1 | 2567 | Arguments: |
74f1a423 | 2568 | ct_ctx client context pointer, or NULL for the one global server context |
dec766a1 | 2569 | shutdown 1 if TLS close-alert is to be sent, |
afdb5e9c | 2570 | 2 if also response to be waited for |
dec766a1 | 2571 | |
17c76198 | 2572 | Returns: nothing |
059ec3d9 PH |
2573 | */ |
2574 | ||
17c76198 | 2575 | void |
74f1a423 | 2576 | tls_close(void * ct_ctx, int shutdown) |
059ec3d9 | 2577 | { |
74f1a423 | 2578 | exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; |
059ec3d9 | 2579 | |
74f1a423 | 2580 | if (!state->tlsp || state->tlsp->active.sock < 0) return; /* TLS was not active */ |
17c76198 PP |
2581 | |
2582 | if (shutdown) | |
2583 | { | |
dec766a1 WB |
2584 | DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n", |
2585 | shutdown > 1 ? " (with response-wait)" : ""); | |
2586 | ||
c2a1bba0 | 2587 | ALARM(2); |
dec766a1 | 2588 | gnutls_bye(state->session, shutdown > 1 ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR); |
c2a1bba0 | 2589 | ALARM_CLR(0); |
17c76198 PP |
2590 | } |
2591 | ||
2592 | gnutls_deinit(state->session); | |
ed62aae3 HSHR |
2593 | gnutls_certificate_free_credentials(state->x509_cred); |
2594 | ||
17c76198 | 2595 | |
74f1a423 JH |
2596 | state->tlsp->active.sock = -1; |
2597 | state->tlsp->active.tls_ctx = NULL; | |
b808677c | 2598 | if (state->xfer_buffer) store_free(state->xfer_buffer); |
17c76198 | 2599 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); |
059ec3d9 PH |
2600 | } |
2601 | ||
2602 | ||
2603 | ||
17c76198 | 2604 | |
0d81dabc JH |
2605 | static BOOL |
2606 | tls_refill(unsigned lim) | |
2607 | { | |
2608 | exim_gnutls_state_st * state = &state_server; | |
2609 | ssize_t inbytes; | |
2610 | ||
2611 | DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(%p, %p, %u)\n", | |
2612 | state->session, state->xfer_buffer, ssl_xfer_buffer_size); | |
2613 | ||
f1fed05b | 2614 | sigalrm_seen = FALSE; |
c2a1bba0 | 2615 | if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); |
4896a319 AM |
2616 | |
2617 | do | |
2618 | inbytes = gnutls_record_recv(state->session, state->xfer_buffer, | |
2619 | MIN(ssl_xfer_buffer_size, lim)); | |
2620 | while (inbytes == GNUTLS_E_AGAIN); | |
2621 | ||
c2a1bba0 | 2622 | if (smtp_receive_timeout > 0) ALARM_CLR(0); |
9723f966 JH |
2623 | |
2624 | if (had_command_timeout) /* set by signal handler */ | |
2625 | smtp_command_timeout_exit(); /* does not return */ | |
2626 | if (had_command_sigterm) | |
2627 | smtp_command_sigterm_exit(); | |
2628 | if (had_data_timeout) | |
2629 | smtp_data_timeout_exit(); | |
2630 | if (had_data_sigint) | |
2631 | smtp_data_sigint_exit(); | |
2632 | ||
2633 | /* Timeouts do not get this far. A zero-byte return appears to mean that the | |
2634 | TLS session has been closed down, not that the socket itself has been closed | |
2635 | down. Revert to non-TLS handling. */ | |
0d81dabc JH |
2636 | |
2637 | if (sigalrm_seen) | |
2638 | { | |
2639 | DEBUG(D_tls) debug_printf("Got tls read timeout\n"); | |
8b77d27a | 2640 | state->xfer_error = TRUE; |
0d81dabc JH |
2641 | return FALSE; |
2642 | } | |
2643 | ||
2644 | else if (inbytes == 0) | |
2645 | { | |
2646 | DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); | |
2647 | ||
2648 | receive_getc = smtp_getc; | |
2649 | receive_getbuf = smtp_getbuf; | |
2650 | receive_get_cache = smtp_get_cache; | |
2651 | receive_ungetc = smtp_ungetc; | |
2652 | receive_feof = smtp_feof; | |
2653 | receive_ferror = smtp_ferror; | |
2654 | receive_smtp_buffered = smtp_buffered; | |
2655 | ||
2656 | gnutls_deinit(state->session); | |
2657 | gnutls_certificate_free_credentials(state->x509_cred); | |
2658 | ||
2659 | state->session = NULL; | |
74f1a423 JH |
2660 | state->tlsp->active.sock = -1; |
2661 | state->tlsp->active.tls_ctx = NULL; | |
0d81dabc JH |
2662 | state->tlsp->bits = 0; |
2663 | state->tlsp->certificate_verified = FALSE; | |
2664 | tls_channelbinding_b64 = NULL; | |
2665 | state->tlsp->cipher = NULL; | |
2666 | state->tlsp->peercert = NULL; | |
2667 | state->tlsp->peerdn = NULL; | |
2668 | ||
2669 | return FALSE; | |
2670 | } | |
2671 | ||
2672 | /* Handle genuine errors */ | |
2673 | ||
2674 | else if (inbytes < 0) | |
2675 | { | |
4896a319 | 2676 | DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv(\n", __FUNCTION__); |
0d81dabc | 2677 | record_io_error(state, (int) inbytes, US"recv", NULL); |
8b77d27a | 2678 | state->xfer_error = TRUE; |
0d81dabc JH |
2679 | return FALSE; |
2680 | } | |
2681 | #ifndef DISABLE_DKIM | |
2682 | dkim_exim_verify_feed(state->xfer_buffer, inbytes); | |
2683 | #endif | |
2684 | state->xfer_buffer_hwm = (int) inbytes; | |
2685 | state->xfer_buffer_lwm = 0; | |
2686 | return TRUE; | |
2687 | } | |
2688 | ||
059ec3d9 PH |
2689 | /************************************************* |
2690 | * TLS version of getc * | |
2691 | *************************************************/ | |
2692 | ||
2693 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
2694 | it refills the buffer via the GnuTLS reading function. | |
817d9f57 | 2695 | Only used by the server-side TLS. |
059ec3d9 | 2696 | |
17c76198 PP |
2697 | This feeds DKIM and should be used for all message-body reads. |
2698 | ||
aded2255 | 2699 | Arguments: lim Maximum amount to read/buffer |
059ec3d9 PH |
2700 | Returns: the next character or EOF |
2701 | */ | |
2702 | ||
2703 | int | |
bd8fbe36 | 2704 | tls_getc(unsigned lim) |
059ec3d9 | 2705 | { |
0d81dabc | 2706 | exim_gnutls_state_st * state = &state_server; |
059ec3d9 | 2707 | |
0d81dabc JH |
2708 | if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) |
2709 | if (!tls_refill(lim)) | |
2710 | return state->xfer_error ? EOF : smtp_getc(lim); | |
ed62aae3 | 2711 | |
0d81dabc | 2712 | /* Something in the buffer; return next uschar */ |
059ec3d9 | 2713 | |
0d81dabc JH |
2714 | return state->xfer_buffer[state->xfer_buffer_lwm++]; |
2715 | } | |
059ec3d9 | 2716 | |
0d81dabc JH |
2717 | uschar * |
2718 | tls_getbuf(unsigned * len) | |
2719 | { | |
2720 | exim_gnutls_state_st * state = &state_server; | |
2721 | unsigned size; | |
2722 | uschar * buf; | |
059ec3d9 | 2723 | |
0d81dabc JH |
2724 | if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) |
2725 | if (!tls_refill(*len)) | |
059ec3d9 | 2726 | { |
0d81dabc JH |
2727 | if (!state->xfer_error) return smtp_getbuf(len); |
2728 | *len = 0; | |
2729 | return NULL; | |
059ec3d9 | 2730 | } |
059ec3d9 | 2731 | |
0d81dabc JH |
2732 | if ((size = state->xfer_buffer_hwm - state->xfer_buffer_lwm) > *len) |
2733 | size = *len; | |
2734 | buf = &state->xfer_buffer[state->xfer_buffer_lwm]; | |
2735 | state->xfer_buffer_lwm += size; | |
2736 | *len = size; | |
2737 | return buf; | |
059ec3d9 PH |
2738 | } |
2739 | ||
0d81dabc | 2740 | |
584e96c6 JH |
2741 | void |
2742 | tls_get_cache() | |
2743 | { | |
9960d1e5 | 2744 | #ifndef DISABLE_DKIM |
584e96c6 JH |
2745 | exim_gnutls_state_st * state = &state_server; |
2746 | int n = state->xfer_buffer_hwm - state->xfer_buffer_lwm; | |
2747 | if (n > 0) | |
2748 | dkim_exim_verify_feed(state->xfer_buffer+state->xfer_buffer_lwm, n); | |
584e96c6 | 2749 | #endif |
9960d1e5 | 2750 | } |
584e96c6 | 2751 | |
059ec3d9 | 2752 | |
925ac8e4 JH |
2753 | BOOL |
2754 | tls_could_read(void) | |
2755 | { | |
2756 | return state_server.xfer_buffer_lwm < state_server.xfer_buffer_hwm | |
2757 | || gnutls_record_check_pending(state_server.session) > 0; | |
2758 | } | |
2759 | ||
2760 | ||
059ec3d9 | 2761 | |
17c76198 | 2762 | |
059ec3d9 PH |
2763 | /************************************************* |
2764 | * Read bytes from TLS channel * | |
2765 | *************************************************/ | |
2766 | ||
17c76198 PP |
2767 | /* This does not feed DKIM, so if the caller uses this for reading message body, |
2768 | then the caller must feed DKIM. | |
817d9f57 | 2769 | |
059ec3d9 | 2770 | Arguments: |
74f1a423 | 2771 | ct_ctx client context pointer, or NULL for the one global server context |
059ec3d9 PH |
2772 | buff buffer of data |
2773 | len size of buffer | |
2774 | ||
2775 | Returns: the number of bytes read | |
afdb5e9c | 2776 | -1 after a failed read, including EOF |
059ec3d9 PH |
2777 | */ |
2778 | ||
2779 | int | |
74f1a423 | 2780 | tls_read(void * ct_ctx, uschar *buff, size_t len) |
059ec3d9 | 2781 | { |
74f1a423 | 2782 | exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; |
17c76198 | 2783 | ssize_t inbytes; |
059ec3d9 | 2784 | |
17c76198 PP |
2785 | if (len > INT_MAX) |
2786 | len = INT_MAX; | |
059ec3d9 | 2787 | |
17c76198 PP |
2788 | if (state->xfer_buffer_lwm < state->xfer_buffer_hwm) |
2789 | DEBUG(D_tls) | |
2790 | debug_printf("*** PROBABLY A BUG *** " \ | |
2791 | "tls_read() called with data in the tls_getc() buffer, %d ignored\n", | |
2792 | state->xfer_buffer_hwm - state->xfer_buffer_lwm); | |
2793 | ||
2794 | DEBUG(D_tls) | |
2795 | debug_printf("Calling gnutls_record_recv(%p, %p, " SIZE_T_FMT ")\n", | |
2796 | state->session, buff, len); | |
2797 | ||
4896a319 AM |
2798 | do |
2799 | inbytes = gnutls_record_recv(state->session, buff, len); | |
2800 | while (inbytes == GNUTLS_E_AGAIN); | |
2801 | ||
059ec3d9 PH |
2802 | if (inbytes > 0) return inbytes; |
2803 | if (inbytes == 0) | |
2804 | { | |
2805 | DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); | |
2806 | } | |
5fd28bb8 | 2807 | else |
4896a319 AM |
2808 | { |
2809 | DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv(\n", __FUNCTION__); | |
2810 | record_io_error(state, (int)inbytes, US"recv", NULL); | |
2811 | } | |
059ec3d9 PH |
2812 | |
2813 | return -1; | |
2814 | } | |
2815 | ||
2816 | ||
2817 | ||
17c76198 | 2818 | |
059ec3d9 PH |
2819 | /************************************************* |
2820 | * Write bytes down TLS channel * | |
2821 | *************************************************/ | |
2822 | ||
2823 | /* | |
2824 | Arguments: | |
74f1a423 | 2825 | ct_ctx client context pointer, or NULL for the one global server context |
059ec3d9 PH |
2826 | buff buffer of data |
2827 | len number of bytes | |
925ac8e4 | 2828 | more more data expected soon |
059ec3d9 PH |
2829 | |
2830 | Returns: the number of bytes after a successful write, | |
2831 | -1 after a failed write | |
2832 | */ | |
2833 | ||
2834 | int | |
74f1a423 | 2835 | tls_write(void * ct_ctx, const uschar * buff, size_t len, BOOL more) |
059ec3d9 | 2836 | { |
17c76198 PP |
2837 | ssize_t outbytes; |
2838 | size_t left = len; | |
74f1a423 | 2839 | exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; |
925ac8e4 JH |
2840 | #ifdef SUPPORT_CORK |
2841 | static BOOL corked = FALSE; | |
2842 | ||
2843 | if (more && !corked) gnutls_record_cork(state->session); | |
2844 | #endif | |
2845 | ||
2846 | DEBUG(D_tls) debug_printf("%s(%p, " SIZE_T_FMT "%s)\n", __FUNCTION__, | |
2847 | buff, left, more ? ", more" : ""); | |
059ec3d9 | 2848 | |
059ec3d9 PH |
2849 | while (left > 0) |
2850 | { | |
17c76198 PP |
2851 | DEBUG(D_tls) debug_printf("gnutls_record_send(SSL, %p, " SIZE_T_FMT ")\n", |
2852 | buff, left); | |
4896a319 AM |
2853 | |
2854 | do | |
2855 | outbytes = gnutls_record_send(state->session, buff, left); | |
2856 | while (outbytes == GNUTLS_E_AGAIN); | |
059ec3d9 | 2857 | |
17c76198 | 2858 | DEBUG(D_tls) debug_printf("outbytes=" SSIZE_T_FMT "\n", outbytes); |
059ec3d9 PH |
2859 | if (outbytes < 0) |
2860 | { | |
1b76ad22 | 2861 | DEBUG(D_tls) debug_printf("%s: gnutls_record_send err\n", __FUNCTION__); |
17c76198 | 2862 | record_io_error(state, outbytes, US"send", NULL); |
059ec3d9 PH |
2863 | return -1; |
2864 | } | |
2865 | if (outbytes == 0) | |
2866 | { | |
17c76198 | 2867 | record_io_error(state, 0, US"send", US"TLS channel closed on write"); |
059ec3d9 PH |
2868 | return -1; |
2869 | } | |
2870 | ||
2871 | left -= outbytes; | |
2872 | buff += outbytes; | |
2873 | } | |
2874 | ||
17c76198 PP |
2875 | if (len > INT_MAX) |
2876 | { | |
2877 | DEBUG(D_tls) | |
2878 | debug_printf("Whoops! Wrote more bytes (" SIZE_T_FMT ") than INT_MAX\n", | |
2879 | len); | |
2880 | len = INT_MAX; | |
2881 | } | |
2882 | ||
925ac8e4 JH |
2883 | #ifdef SUPPORT_CORK |
2884 | if (more != corked) | |
2885 | { | |
2886 | if (!more) (void) gnutls_record_uncork(state->session, 0); | |
2887 | corked = more; | |
2888 | } | |
2889 | #endif | |
2890 | ||
17c76198 | 2891 | return (int) len; |
059ec3d9 PH |
2892 | } |
2893 | ||
2894 | ||
2895 | ||
17c76198 | 2896 | |
059ec3d9 | 2897 | /************************************************* |
17c76198 | 2898 | * Random number generation * |
059ec3d9 PH |
2899 | *************************************************/ |
2900 | ||
17c76198 PP |
2901 | /* Pseudo-random number generation. The result is not expected to be |
2902 | cryptographically strong but not so weak that someone will shoot themselves | |
2903 | in the foot using it as a nonce in input in some email header scheme or | |
2904 | whatever weirdness they'll twist this into. The result should handle fork() | |
2905 | and avoid repeating sequences. OpenSSL handles that for us. | |
059ec3d9 | 2906 | |
17c76198 PP |
2907 | Arguments: |
2908 | max range maximum | |
2909 | Returns a random number in range [0, max-1] | |
059ec3d9 PH |
2910 | */ |
2911 | ||
af3498d6 | 2912 | #ifdef HAVE_GNUTLS_RND |
17c76198 PP |
2913 | int |
2914 | vaguely_random_number(int max) | |
059ec3d9 | 2915 | { |
17c76198 PP |
2916 | unsigned int r; |
2917 | int i, needed_len; | |
17c76198 PP |
2918 | uschar smallbuf[sizeof(r)]; |
2919 | ||
2920 | if (max <= 1) | |
2921 | return 0; | |
2922 | ||
2923 | needed_len = sizeof(r); | |
2924 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
d7978c0f JH |
2925 | asked for a number less than 10. */ |
2926 | ||
17c76198 PP |
2927 | for (r = max, i = 0; r; ++i) |
2928 | r >>= 1; | |
2929 | i = (i + 7) / 8; | |
2930 | if (i < needed_len) | |
2931 | needed_len = i; | |
2932 | ||
2933 | i = gnutls_rnd(GNUTLS_RND_NONCE, smallbuf, needed_len); | |
2934 | if (i < 0) | |
059ec3d9 | 2935 | { |
17c76198 PP |
2936 | DEBUG(D_all) debug_printf("gnutls_rnd() failed, using fallback.\n"); |
2937 | return vaguely_random_number_fallback(max); | |
2938 | } | |
2939 | r = 0; | |
d7978c0f JH |
2940 | for (uschar * p = smallbuf; needed_len; --needed_len, ++p) |
2941 | r = r * 256 + *p; | |
059ec3d9 | 2942 | |
17c76198 PP |
2943 | /* We don't particularly care about weighted results; if someone wants |
2944 | * smooth distribution and cares enough then they should submit a patch then. */ | |
2945 | return r % max; | |
059ec3d9 | 2946 | } |
af3498d6 PP |
2947 | #else /* HAVE_GNUTLS_RND */ |
2948 | int | |
2949 | vaguely_random_number(int max) | |
2950 | { | |
2951 | return vaguely_random_number_fallback(max); | |
2952 | } | |
2953 | #endif /* HAVE_GNUTLS_RND */ | |
059ec3d9 | 2954 | |
36f12725 NM |
2955 | |
2956 | ||
2957 | ||
3375e053 PP |
2958 | /************************************************* |
2959 | * Let tls_require_ciphers be checked at startup * | |
2960 | *************************************************/ | |
2961 | ||
2962 | /* The tls_require_ciphers option, if set, must be something which the | |
2963 | library can parse. | |
2964 | ||
2965 | Returns: NULL on success, or error message | |
2966 | */ | |
2967 | ||
2968 | uschar * | |
2969 | tls_validate_require_cipher(void) | |
2970 | { | |
2971 | int rc; | |
2972 | uschar *expciphers = NULL; | |
2973 | gnutls_priority_t priority_cache; | |
2974 | const char *errpos; | |
cf0c6164 | 2975 | uschar * dummy_errstr; |
3375e053 PP |
2976 | |
2977 | #define validate_check_rc(Label) do { \ | |
2978 | if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) gnutls_global_deinit(); \ | |
2979 | return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0) | |
2980 | #define return_deinit(Label) do { gnutls_global_deinit(); return (Label); } while (0) | |
2981 | ||
2982 | if (exim_gnutls_base_init_done) | |
2983 | log_write(0, LOG_MAIN|LOG_PANIC, | |
2984 | "already initialised GnuTLS, Exim developer bug"); | |
2985 | ||
a5f239e4 | 2986 | #ifdef HAVE_GNUTLS_PKCS11 |
2519e60d | 2987 | if (!gnutls_allow_auto_pkcs11) |
a5f239e4 PP |
2988 | { |
2989 | rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL); | |
2990 | validate_check_rc(US"gnutls_pkcs11_init"); | |
2991 | } | |
2992 | #endif | |
3375e053 PP |
2993 | rc = gnutls_global_init(); |
2994 | validate_check_rc(US"gnutls_global_init()"); | |
2995 | exim_gnutls_base_init_done = TRUE; | |
2996 | ||
2997 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
2998 | return_deinit(NULL); | |
2999 | ||
cf0c6164 JH |
3000 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers, |
3001 | &dummy_errstr)) | |
3375e053 PP |
3002 | return_deinit(US"failed to expand tls_require_ciphers"); |
3003 | ||
3004 | if (!(expciphers && *expciphers)) | |
3005 | return_deinit(NULL); | |
3006 | ||
3007 | DEBUG(D_tls) | |
3008 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
3009 | ||
3010 | rc = gnutls_priority_init(&priority_cache, CS expciphers, &errpos); | |
3011 | validate_check_rc(string_sprintf( | |
3012 | "gnutls_priority_init(%s) failed at offset %ld, \"%.8s..\"", | |
3013 | expciphers, errpos - CS expciphers, errpos)); | |
3014 | ||
3015 | #undef return_deinit | |
3016 | #undef validate_check_rc | |
3017 | gnutls_global_deinit(); | |
3018 | ||
3019 | return NULL; | |
3020 | } | |
3021 | ||
3022 | ||
3023 | ||
3024 | ||
36f12725 NM |
3025 | /************************************************* |
3026 | * Report the library versions. * | |
3027 | *************************************************/ | |
3028 | ||
3029 | /* See a description in tls-openssl.c for an explanation of why this exists. | |
3030 | ||
3031 | Arguments: a FILE* to print the results to | |
3032 | Returns: nothing | |
3033 | */ | |
3034 | ||
3035 | void | |
3036 | tls_version_report(FILE *f) | |
3037 | { | |
754a0503 PP |
3038 | fprintf(f, "Library version: GnuTLS: Compile: %s\n" |
3039 | " Runtime: %s\n", | |
3040 | LIBGNUTLS_VERSION, | |
3041 | gnutls_check_version(NULL)); | |
36f12725 NM |
3042 | } |
3043 | ||
2b4a568d JH |
3044 | /* vi: aw ai sw=2 |
3045 | */ | |
059ec3d9 | 3046 | /* End of tls-gnu.c */ |