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 | |
4d2a62a3 JH |
73 | #if GNUTLS_VERSION_NUMBER >= 0x030300 |
74 | # define GNUTLS_AUTO_GLOBAL_INIT | |
9f707b89 | 75 | # define GNUTLS_AUTO_PKCS11_MANUAL |
4d2a62a3 | 76 | #endif |
f20cfa4a JH |
77 | #if GNUTLS_VERSION_NUMBER >= 0x030500 |
78 | # define SUPPORT_GNUTLS_KEYLOG | |
79 | #endif | |
47195144 JH |
80 | #if GNUTLS_VERSION_NUMBER >= 0x030506 && !defined(DISABLE_OCSP) |
81 | # define SUPPORT_SRV_OCSP_STACK | |
82 | #endif | |
49132a3b JH |
83 | #if GNUTLS_VERSION_NUMBER >= 0x030600 |
84 | # define GNUTLS_AUTO_DHPARAMS | |
85 | #endif | |
be427508 | 86 | #if GNUTLS_VERSION_NUMBER >= 0x030603 |
e326959e | 87 | # define EXIM_HAVE_TLS1_3 |
be427508 | 88 | # define SUPPORT_GNUTLS_EXT_RAW_PARSE |
e326959e | 89 | # define GNUTLS_OCSP_STATUS_REQUEST_GET2 |
be427508 | 90 | #endif |
c0635b6d JH |
91 | |
92 | #ifdef SUPPORT_DANE | |
93 | # if GNUTLS_VERSION_NUMBER >= 0x030000 | |
94 | # define DANESSL_USAGE_DANE_TA 2 | |
95 | # define DANESSL_USAGE_DANE_EE 3 | |
96 | # else | |
97 | # error GnuTLS version too early for DANE | |
98 | # endif | |
99 | # if GNUTLS_VERSION_NUMBER < 0x999999 | |
100 | # define GNUTLS_BROKEN_DANE_VALIDATION | |
101 | # endif | |
899b8bbc | 102 | #endif |
7e07527a | 103 | |
43e2db44 JH |
104 | #ifdef EXPERIMENTAL_TLS_RESUME |
105 | # if GNUTLS_VERSION_NUMBER < 0x030603 | |
106 | # error GNUTLS version too early for session-resumption | |
107 | # endif | |
108 | #endif | |
109 | ||
f2de3a33 | 110 | #ifndef DISABLE_OCSP |
2b4a568d JH |
111 | # include <gnutls/ocsp.h> |
112 | #endif | |
899b8bbc JH |
113 | #ifdef SUPPORT_DANE |
114 | # include <gnutls/dane.h> | |
115 | #endif | |
059ec3d9 | 116 | |
f1be21cf JH |
117 | #include "tls-cipher-stdname.c" |
118 | ||
119 | ||
b10c87b3 JH |
120 | #ifdef MACRO_PREDEF |
121 | void | |
122 | options_tls(void) | |
123 | { | |
124 | # ifdef EXPERIMENTAL_TLS_RESUME | |
125 | builtin_macro_create_var(US"_RESUME_DECODE", RESUME_DECODE_STRING ); | |
126 | # endif | |
e326959e JH |
127 | # ifdef EXIM_HAVE_TLS1_3 |
128 | builtin_macro_create(US"_HAVE_TLS1_3"); | |
129 | # endif | |
b10c87b3 JH |
130 | } |
131 | #else | |
132 | ||
133 | ||
17c76198 | 134 | /* GnuTLS 2 vs 3 |
059ec3d9 | 135 | |
17c76198 PP |
136 | GnuTLS 3 only: |
137 | gnutls_global_set_audit_log_function() | |
059ec3d9 | 138 | |
17c76198 PP |
139 | Changes: |
140 | gnutls_certificate_verify_peers2(): is new, drop the 2 for old version | |
141 | */ | |
059ec3d9 | 142 | |
17c76198 | 143 | /* Local static variables for GnuTLS */ |
059ec3d9 | 144 | |
17c76198 | 145 | /* Values for verify_requirement */ |
059ec3d9 | 146 | |
e51c7be2 | 147 | enum peer_verify_requirement |
899b8bbc | 148 | { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED, VERIFY_DANE }; |
059ec3d9 | 149 | |
17c76198 PP |
150 | /* This holds most state for server or client; with this, we can set up an |
151 | outbound TLS-enabled connection in an ACL callout, while not stomping all | |
152 | over the TLS variables available for expansion. | |
059ec3d9 | 153 | |
17c76198 PP |
154 | Some of these correspond to variables in globals.c; those variables will |
155 | be set to point to content in one of these instances, as appropriate for | |
156 | the stage of the process lifetime. | |
059ec3d9 | 157 | |
b1a32a3c | 158 | Not handled here: global tlsp->tls_channelbinding. |
17c76198 | 159 | */ |
059ec3d9 | 160 | |
17c76198 | 161 | typedef struct exim_gnutls_state { |
9d1c15ef | 162 | gnutls_session_t session; |
17c76198 | 163 | gnutls_certificate_credentials_t x509_cred; |
9d1c15ef | 164 | gnutls_priority_t priority_cache; |
17c76198 | 165 | enum peer_verify_requirement verify_requirement; |
9d1c15ef JH |
166 | int fd_in; |
167 | int fd_out; | |
168 | BOOL peer_cert_verified; | |
899b8bbc | 169 | BOOL peer_dane_verified; |
9d1c15ef JH |
170 | BOOL trigger_sni_changes; |
171 | BOOL have_set_peerdn; | |
5fd28bb8 | 172 | const struct host_item *host; /* NULL if server */ |
afdb5e9c | 173 | gnutls_x509_crt_t peercert; |
9d1c15ef JH |
174 | uschar *peerdn; |
175 | uschar *ciphersuite; | |
176 | uschar *received_sni; | |
17c76198 PP |
177 | |
178 | const uschar *tls_certificate; | |
179 | const uschar *tls_privatekey; | |
180 | const uschar *tls_sni; /* client send only, not received */ | |
181 | const uschar *tls_verify_certificates; | |
182 | const uschar *tls_crl; | |
183 | const uschar *tls_require_ciphers; | |
e51c7be2 | 184 | |
17c76198 PP |
185 | uschar *exp_tls_certificate; |
186 | uschar *exp_tls_privatekey; | |
17c76198 PP |
187 | uschar *exp_tls_verify_certificates; |
188 | uschar *exp_tls_crl; | |
189 | uschar *exp_tls_require_ciphers; | |
55414b25 | 190 | const uschar *exp_tls_verify_cert_hostnames; |
0cbf2b82 | 191 | #ifndef DISABLE_EVENT |
a7538db1 JH |
192 | uschar *event_action; |
193 | #endif | |
899b8bbc JH |
194 | #ifdef SUPPORT_DANE |
195 | char * const * dane_data; | |
196 | const int * dane_data_len; | |
197 | #endif | |
17c76198 | 198 | |
389ca47a | 199 | tls_support *tlsp; /* set in tls_init() */ |
817d9f57 | 200 | |
17c76198 PP |
201 | uschar *xfer_buffer; |
202 | int xfer_buffer_lwm; | |
203 | int xfer_buffer_hwm; | |
8b77d27a JH |
204 | BOOL xfer_eof; /*XXX never gets set! */ |
205 | BOOL xfer_error; | |
17c76198 PP |
206 | } exim_gnutls_state_st; |
207 | ||
208 | static const exim_gnutls_state_st exim_gnutls_state_init = { | |
b10c87b3 | 209 | /* all elements not explicitly intialised here get 0/NULL/FALSE */ |
f2ed27cf JH |
210 | .fd_in = -1, |
211 | .fd_out = -1, | |
17c76198 | 212 | }; |
83da1223 | 213 | |
17c76198 PP |
214 | /* Not only do we have our own APIs which don't pass around state, assuming |
215 | it's held in globals, GnuTLS doesn't appear to let us register callback data | |
216 | for callbacks, or as part of the session, so we have to keep a "this is the | |
217 | context we're currently dealing with" pointer and rely upon being | |
218 | single-threaded to keep from processing data on an inbound TLS connection while | |
219 | talking to another TLS connection for an outbound check. This does mean that | |
220 | there's no way for heart-beats to be responded to, for the duration of the | |
a7538db1 JH |
221 | second connection. |
222 | XXX But see gnutls_session_get_ptr() | |
223 | */ | |
059ec3d9 | 224 | |
74f1a423 | 225 | static exim_gnutls_state_st state_server; |
059ec3d9 | 226 | |
49132a3b | 227 | #ifndef GNUTLS_AUTO_DHPARAMS |
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; |
49132a3b | 233 | #endif |
059ec3d9 | 234 | |
dea4b568 | 235 | static int ssl_session_timeout = 7200; /* Two hours */ |
059ec3d9 | 236 | |
fc243e94 | 237 | static const uschar * const exim_default_gnutls_priority = US"NORMAL"; |
83da1223 | 238 | |
17c76198 | 239 | /* Guard library core initialisation */ |
83da1223 | 240 | |
17c76198 | 241 | static BOOL exim_gnutls_base_init_done = FALSE; |
059ec3d9 | 242 | |
4fb7df6d | 243 | #ifndef DISABLE_OCSP |
9196d5bf | 244 | static BOOL gnutls_buggy_ocsp = FALSE; |
e5489333 | 245 | static BOOL exim_testharness_disable_ocsp_validity_check = FALSE; |
4fb7df6d | 246 | #endif |
9196d5bf | 247 | |
b10c87b3 JH |
248 | #ifdef EXPERIMENTAL_TLS_RESUME |
249 | static gnutls_datum_t server_sessticket_key; | |
250 | #endif | |
059ec3d9 | 251 | |
17c76198 PP |
252 | /* ------------------------------------------------------------------------ */ |
253 | /* macros */ | |
83da1223 | 254 | |
17c76198 | 255 | #define MAX_HOST_LEN 255 |
83da1223 | 256 | |
17c76198 PP |
257 | /* Set this to control gnutls_global_set_log_level(); values 0 to 9 will setup |
258 | the library logging; a value less than 0 disables the calls to set up logging | |
dc6d1769 JH |
259 | callbacks. GNuTLS also looks for an environment variable - except not for |
260 | setuid binaries, making it useless - "GNUTLS_DEBUG_LEVEL". | |
261 | Allegedly the testscript line "GNUTLS_DEBUG_LEVEL=9 sudo exim ..." would work, | |
262 | but the env var must be added to /etc/sudoers too. */ | |
2c17bb02 | 263 | #ifndef EXIM_GNUTLS_LIBRARY_LOG_LEVEL |
b1a4f234 | 264 | # define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1 |
2c17bb02 | 265 | #endif |
83da1223 | 266 | |
2c17bb02 | 267 | #ifndef EXIM_CLIENT_DH_MIN_BITS |
a7538db1 | 268 | # define EXIM_CLIENT_DH_MIN_BITS 1024 |
2c17bb02 | 269 | #endif |
83da1223 | 270 | |
af3498d6 PP |
271 | /* With GnuTLS 2.12.x+ we have gnutls_sec_param_to_pk_bits() with which we |
272 | can ask for a bit-strength. Without that, we stick to the constant we had | |
273 | before, for now. */ | |
2c17bb02 | 274 | #ifndef EXIM_SERVER_DH_BITS_PRE2_12 |
a7538db1 | 275 | # define EXIM_SERVER_DH_BITS_PRE2_12 1024 |
2c17bb02 | 276 | #endif |
af3498d6 | 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 | ||
e5489333 JH |
308 | #ifdef EXPERIMENTAL_TLS_RESUME |
309 | static int | |
310 | tls_server_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when, | |
311 | unsigned incoming, const gnutls_datum_t * msg); | |
312 | #endif | |
af3498d6 PP |
313 | |
314 | ||
b10c87b3 JH |
315 | /* Daemon one-time initialisation */ |
316 | void | |
317 | tls_daemon_init(void) | |
318 | { | |
319 | #ifdef EXPERIMENTAL_TLS_RESUME | |
320 | /* We are dependent on the GnuTLS implementation of the Session Ticket | |
321 | encryption; both the strength and the key rotation period. We hope that | |
322 | the strength at least matches that of the ciphersuite (but GnuTLS does not | |
323 | document this). */ | |
324 | ||
325 | static BOOL once = FALSE; | |
326 | if (once) return; | |
327 | once = TRUE; | |
328 | gnutls_session_ticket_key_generate(&server_sessticket_key); /* >= 2.10.0 */ | |
329 | if (f.running_in_test_harness) ssl_session_timeout = 6; | |
330 | #endif | |
331 | } | |
332 | ||
17c76198 PP |
333 | /* ------------------------------------------------------------------------ */ |
334 | /* Static functions */ | |
059ec3d9 PH |
335 | |
336 | /************************************************* | |
337 | * Handle TLS error * | |
338 | *************************************************/ | |
339 | ||
340 | /* Called from lots of places when errors occur before actually starting to do | |
341 | the TLS handshake, that is, while the session is still in clear. Always returns | |
342 | DEFER for a server and FAIL for a client so that most calls can use "return | |
343 | tls_error(...)" to do this processing and then give an appropriate return. A | |
344 | single function is used for both server and client, because it is called from | |
345 | some shared functions. | |
346 | ||
347 | Argument: | |
348 | prefix text to include in the logged error | |
7199e1ee TF |
349 | msg additional error string (may be NULL) |
350 | usually obtained from gnutls_strerror() | |
17c76198 PP |
351 | host NULL if setting up a server; |
352 | the connected host if setting up a client | |
cf0c6164 | 353 | errstr pointer to returned error string |
059ec3d9 PH |
354 | |
355 | Returns: OK/DEFER/FAIL | |
356 | */ | |
357 | ||
358 | static int | |
48224640 | 359 | tls_error(const uschar *prefix, const uschar *msg, const host_item *host, |
cf0c6164 | 360 | uschar ** errstr) |
059ec3d9 | 361 | { |
cf0c6164 | 362 | if (errstr) |
48224640 | 363 | *errstr = string_sprintf("(%s)%s%s", prefix, msg ? ": " : "", msg ? msg : US""); |
cf0c6164 | 364 | return host ? FAIL : DEFER; |
059ec3d9 PH |
365 | } |
366 | ||
367 | ||
452a164f JH |
368 | static int |
369 | tls_error_gnu(const uschar *prefix, int err, const host_item *host, | |
370 | uschar ** errstr) | |
371 | { | |
372 | return tls_error(prefix, US gnutls_strerror(err), host, errstr); | |
373 | } | |
374 | ||
375 | static int | |
376 | tls_error_sys(const uschar *prefix, int err, const host_item *host, | |
377 | uschar ** errstr) | |
378 | { | |
379 | return tls_error(prefix, US strerror(err), host, errstr); | |
380 | } | |
059ec3d9 | 381 | |
17c76198 | 382 | |
059ec3d9 | 383 | /************************************************* |
17c76198 | 384 | * Deal with logging errors during I/O * |
059ec3d9 PH |
385 | *************************************************/ |
386 | ||
17c76198 | 387 | /* We have to get the identity of the peer from saved data. |
059ec3d9 | 388 | |
17c76198 PP |
389 | Argument: |
390 | state the current GnuTLS exim state container | |
391 | rc the GnuTLS error code, or 0 if it's a local error | |
392 | when text identifying read or write | |
95f52235 | 393 | text local error text when rc is 0 |
059ec3d9 | 394 | |
17c76198 | 395 | Returns: nothing |
059ec3d9 PH |
396 | */ |
397 | ||
17c76198 PP |
398 | static void |
399 | record_io_error(exim_gnutls_state_st *state, int rc, uschar *when, uschar *text) | |
059ec3d9 | 400 | { |
48224640 | 401 | const uschar * msg; |
cf0c6164 | 402 | uschar * errstr; |
059ec3d9 | 403 | |
17c76198 | 404 | if (rc == GNUTLS_E_FATAL_ALERT_RECEIVED) |
95f52235 | 405 | msg = string_sprintf("A TLS fatal alert has been received: %s", |
17c76198 PP |
406 | US gnutls_alert_get_name(gnutls_alert_get(state->session))); |
407 | else | |
48224640 | 408 | msg = US gnutls_strerror(rc); |
059ec3d9 | 409 | |
cf0c6164 JH |
410 | (void) tls_error(when, msg, state->host, &errstr); |
411 | ||
412 | if (state->host) | |
413 | log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection %s", | |
414 | state->host->name, state->host->address, errstr); | |
415 | else | |
416 | { | |
417 | uschar * conn_info = smtp_get_connection_info(); | |
418 | if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5; | |
419 | /* I'd like to get separated H= here, but too hard for now */ | |
420 | log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr); | |
421 | } | |
17c76198 | 422 | } |
059ec3d9 | 423 | |
059ec3d9 | 424 | |
059ec3d9 | 425 | |
059ec3d9 | 426 | |
17c76198 PP |
427 | /************************************************* |
428 | * Set various Exim expansion vars * | |
429 | *************************************************/ | |
059ec3d9 | 430 | |
e51c7be2 JH |
431 | #define exim_gnutls_cert_err(Label) \ |
432 | do \ | |
433 | { \ | |
434 | if (rc != GNUTLS_E_SUCCESS) \ | |
435 | { \ | |
436 | DEBUG(D_tls) debug_printf("TLS: cert problem: %s: %s\n", \ | |
437 | (Label), gnutls_strerror(rc)); \ | |
438 | return rc; \ | |
439 | } \ | |
440 | } while (0) | |
9d1c15ef JH |
441 | |
442 | static int | |
27f19eb4 | 443 | import_cert(const gnutls_datum_t * cert, gnutls_x509_crt_t * crtp) |
9d1c15ef JH |
444 | { |
445 | int rc; | |
446 | ||
447 | rc = gnutls_x509_crt_init(crtp); | |
448 | exim_gnutls_cert_err(US"gnutls_x509_crt_init (crt)"); | |
449 | ||
450 | rc = gnutls_x509_crt_import(*crtp, cert, GNUTLS_X509_FMT_DER); | |
451 | exim_gnutls_cert_err(US"failed to import certificate [gnutls_x509_crt_import(cert)]"); | |
452 | ||
453 | return rc; | |
454 | } | |
455 | ||
456 | #undef exim_gnutls_cert_err | |
457 | ||
458 | ||
17c76198 PP |
459 | /* We set various Exim global variables from the state, once a session has |
460 | been established. With TLS callouts, may need to change this to stack | |
461 | variables, or just re-call it with the server state after client callout | |
462 | has finished. | |
059ec3d9 | 463 | |
9d1c15ef | 464 | Make sure anything set here is unset in tls_getc(). |
17c76198 PP |
465 | |
466 | Sets: | |
467 | tls_active fd | |
468 | tls_bits strength indicator | |
469 | tls_certificate_verified bool indicator | |
b1a32a3c | 470 | tls_channelbinding for some SASL mechanisms |
5b195d6b | 471 | tls_ver a string |
17c76198 | 472 | tls_cipher a string |
9d1c15ef | 473 | tls_peercert pointer to library internal |
17c76198 PP |
474 | tls_peerdn a string |
475 | tls_sni a (UTF-8) string | |
9d1c15ef | 476 | tls_ourcert pointer to library internal |
17c76198 PP |
477 | |
478 | Argument: | |
479 | state the relevant exim_gnutls_state_st * | |
480 | */ | |
481 | ||
482 | static void | |
9d1c15ef | 483 | extract_exim_vars_from_tls_state(exim_gnutls_state_st * state) |
17c76198 | 484 | { |
17c76198 PP |
485 | #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING |
486 | int old_pool; | |
487 | int rc; | |
488 | gnutls_datum_t channel; | |
489 | #endif | |
9d1c15ef | 490 | tls_support * tlsp = state->tlsp; |
17c76198 | 491 | |
74f1a423 JH |
492 | tlsp->active.sock = state->fd_out; |
493 | tlsp->active.tls_ctx = state; | |
17c76198 | 494 | |
817d9f57 | 495 | DEBUG(D_tls) debug_printf("cipher: %s\n", state->ciphersuite); |
17c76198 | 496 | |
9d1c15ef | 497 | tlsp->certificate_verified = state->peer_cert_verified; |
899b8bbc JH |
498 | #ifdef SUPPORT_DANE |
499 | tlsp->dane_verified = state->peer_dane_verified; | |
500 | #endif | |
059ec3d9 | 501 | |
b1a32a3c | 502 | /* note that tls_channelbinding is not saved to the spool file, since it's |
17c76198 PP |
503 | only available for use for authenticators while this TLS session is running. */ |
504 | ||
b1a32a3c | 505 | tlsp->channelbinding = NULL; |
17c76198 PP |
506 | #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING |
507 | channel.data = NULL; | |
508 | channel.size = 0; | |
1f20760b JH |
509 | if ((rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel))) |
510 | { DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc)); } | |
511 | else | |
512 | { | |
b1a32a3c JH |
513 | /* Declare the taintedness of the binding info. On server, untainted; on |
514 | client, tainted - being the Finish msg from the server. */ | |
515 | ||
17c76198 PP |
516 | old_pool = store_pool; |
517 | store_pool = POOL_PERM; | |
b1a32a3c JH |
518 | tlsp->channelbinding = b64encode_taint(CUS channel.data, (int)channel.size, |
519 | !!state->host); | |
17c76198 | 520 | store_pool = old_pool; |
b1a32a3c | 521 | DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage\n"); |
1f20760b | 522 | } |
17c76198 PP |
523 | #endif |
524 | ||
9d1c15ef JH |
525 | /* peercert is set in peer_status() */ |
526 | tlsp->peerdn = state->peerdn; | |
527 | tlsp->sni = state->received_sni; | |
528 | ||
529 | /* record our certificate */ | |
530 | { | |
27f19eb4 | 531 | const gnutls_datum_t * cert = gnutls_certificate_get_ours(state->session); |
9d1c15ef JH |
532 | gnutls_x509_crt_t crt; |
533 | ||
534 | tlsp->ourcert = cert && import_cert(cert, &crt)==0 ? crt : NULL; | |
535 | } | |
059ec3d9 PH |
536 | } |
537 | ||
538 | ||
539 | ||
17c76198 | 540 | |
49132a3b | 541 | #ifndef GNUTLS_AUTO_DHPARAMS |
059ec3d9 | 542 | /************************************************* |
575643cd | 543 | * Setup up DH parameters * |
059ec3d9 PH |
544 | *************************************************/ |
545 | ||
575643cd | 546 | /* Generating the D-H parameters may take a long time. They only need to |
059ec3d9 PH |
547 | be re-generated every so often, depending on security policy. What we do is to |
548 | keep these parameters in a file in the spool directory. If the file does not | |
549 | exist, we generate them. This means that it is easy to cause a regeneration. | |
550 | ||
551 | The new file is written as a temporary file and renamed, so that an incomplete | |
552 | file is never present. If two processes both compute some new parameters, you | |
553 | waste a bit of effort, but it doesn't seem worth messing around with locking to | |
554 | prevent this. | |
555 | ||
059ec3d9 PH |
556 | Returns: OK/DEFER/FAIL |
557 | */ | |
558 | ||
559 | static int | |
cf0c6164 | 560 | init_server_dh(uschar ** errstr) |
059ec3d9 | 561 | { |
17c76198 PP |
562 | int fd, rc; |
563 | unsigned int dh_bits; | |
49132a3b | 564 | gnutls_datum_t m = {.data = NULL, .size = 0}; |
a799883d PP |
565 | uschar filename_buf[PATH_MAX]; |
566 | uschar *filename = NULL; | |
17c76198 | 567 | size_t sz; |
a799883d PP |
568 | uschar *exp_tls_dhparam; |
569 | BOOL use_file_in_spool = FALSE; | |
17c76198 | 570 | host_item *host = NULL; /* dummy for macros */ |
059ec3d9 | 571 | |
17c76198 | 572 | DEBUG(D_tls) debug_printf("Initialising GnuTLS server params.\n"); |
059ec3d9 | 573 | |
452a164f JH |
574 | if ((rc = gnutls_dh_params_init(&dh_server_params))) |
575 | return tls_error_gnu(US"gnutls_dh_params_init", rc, host, errstr); | |
059ec3d9 | 576 | |
cf0c6164 | 577 | if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam, errstr)) |
a799883d PP |
578 | return DEFER; |
579 | ||
580 | if (!exp_tls_dhparam) | |
581 | { | |
582 | DEBUG(D_tls) debug_printf("Loading default hard-coded DH params\n"); | |
583 | m.data = US std_dh_prime_default(); | |
584 | m.size = Ustrlen(m.data); | |
585 | } | |
586 | else if (Ustrcmp(exp_tls_dhparam, "historic") == 0) | |
587 | use_file_in_spool = TRUE; | |
588 | else if (Ustrcmp(exp_tls_dhparam, "none") == 0) | |
589 | { | |
590 | DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); | |
591 | return OK; | |
592 | } | |
593 | else if (exp_tls_dhparam[0] != '/') | |
594 | { | |
f5d25c2b | 595 | if (!(m.data = US std_dh_prime_named(exp_tls_dhparam))) |
48224640 | 596 | return tls_error(US"No standard prime named", exp_tls_dhparam, NULL, errstr); |
a799883d PP |
597 | m.size = Ustrlen(m.data); |
598 | } | |
599 | else | |
a799883d | 600 | filename = exp_tls_dhparam; |
a799883d PP |
601 | |
602 | if (m.data) | |
603 | { | |
452a164f JH |
604 | if ((rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM))) |
605 | return tls_error_gnu(US"gnutls_dh_params_import_pkcs3", rc, host, errstr); | |
a799883d PP |
606 | DEBUG(D_tls) debug_printf("Loaded fixed standard D-H parameters\n"); |
607 | return OK; | |
608 | } | |
609 | ||
af3498d6 PP |
610 | #ifdef HAVE_GNUTLS_SEC_PARAM_CONSTANTS |
611 | /* If you change this constant, also change dh_param_fn_ext so that we can use a | |
17c76198 | 612 | different filename and ensure we have sufficient bits. */ |
452a164f JH |
613 | |
614 | if (!(dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL))) | |
cf0c6164 | 615 | return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL, errstr); |
af3498d6 | 616 | DEBUG(D_tls) |
b34fc30c | 617 | debug_printf("GnuTLS tells us that for D-H PK, NORMAL is %d bits.\n", |
af3498d6 PP |
618 | dh_bits); |
619 | #else | |
620 | dh_bits = EXIM_SERVER_DH_BITS_PRE2_12; | |
621 | DEBUG(D_tls) | |
622 | debug_printf("GnuTLS lacks gnutls_sec_param_to_pk_bits(), using %d bits.\n", | |
623 | dh_bits); | |
624 | #endif | |
059ec3d9 | 625 | |
3375e053 PP |
626 | /* Some clients have hard-coded limits. */ |
627 | if (dh_bits > tls_dh_max_bits) | |
628 | { | |
629 | DEBUG(D_tls) | |
630 | debug_printf("tls_dh_max_bits clamping override, using %d bits instead.\n", | |
631 | tls_dh_max_bits); | |
632 | dh_bits = tls_dh_max_bits; | |
633 | } | |
634 | ||
a799883d PP |
635 | if (use_file_in_spool) |
636 | { | |
637 | if (!string_format(filename_buf, sizeof(filename_buf), | |
638 | "%s/gnutls-params-%d", spool_directory, dh_bits)) | |
cf0c6164 | 639 | return tls_error(US"overlong filename", NULL, NULL, errstr); |
a799883d PP |
640 | filename = filename_buf; |
641 | } | |
059ec3d9 | 642 | |
b5aea5e1 | 643 | /* Open the cache file for reading and if successful, read it and set up the |
575643cd | 644 | parameters. */ |
059ec3d9 | 645 | |
f5d25c2b | 646 | if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) |
059ec3d9 | 647 | { |
b5aea5e1 | 648 | struct stat statbuf; |
17c76198 PP |
649 | FILE *fp; |
650 | int saved_errno; | |
651 | ||
652 | if (fstat(fd, &statbuf) < 0) /* EIO */ | |
653 | { | |
654 | saved_errno = errno; | |
655 | (void)close(fd); | |
452a164f | 656 | return tls_error_sys(US"TLS cache stat failed", saved_errno, NULL, errstr); |
17c76198 PP |
657 | } |
658 | if (!S_ISREG(statbuf.st_mode)) | |
b5aea5e1 PH |
659 | { |
660 | (void)close(fd); | |
cf0c6164 | 661 | return tls_error(US"TLS cache not a file", NULL, NULL, errstr); |
17c76198 | 662 | } |
40c90bca | 663 | if (!(fp = fdopen(fd, "rb"))) |
17c76198 PP |
664 | { |
665 | saved_errno = errno; | |
666 | (void)close(fd); | |
452a164f JH |
667 | return tls_error_sys(US"fdopen(TLS cache stat fd) failed", |
668 | saved_errno, NULL, errstr); | |
b5aea5e1 | 669 | } |
059ec3d9 | 670 | |
b5aea5e1 | 671 | m.size = statbuf.st_size; |
f3ebb786 | 672 | if (!(m.data = store_malloc(m.size))) |
17c76198 PP |
673 | { |
674 | fclose(fp); | |
452a164f | 675 | return tls_error_sys(US"malloc failed", errno, NULL, errstr); |
17c76198 | 676 | } |
40c90bca | 677 | if (!(sz = fread(m.data, m.size, 1, fp))) |
17c76198 PP |
678 | { |
679 | saved_errno = errno; | |
680 | fclose(fp); | |
f3ebb786 | 681 | store_free(m.data); |
452a164f | 682 | return tls_error_sys(US"fread failed", saved_errno, NULL, errstr); |
17c76198 PP |
683 | } |
684 | fclose(fp); | |
b5aea5e1 | 685 | |
17c76198 | 686 | rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM); |
f3ebb786 | 687 | store_free(m.data); |
452a164f JH |
688 | if (rc) |
689 | return tls_error_gnu(US"gnutls_dh_params_import_pkcs3", rc, host, errstr); | |
17c76198 | 690 | DEBUG(D_tls) debug_printf("read D-H parameters from file \"%s\"\n", filename); |
b5aea5e1 PH |
691 | } |
692 | ||
693 | /* If the file does not exist, fall through to compute new data and cache it. | |
694 | If there was any other opening error, it is serious. */ | |
695 | ||
182ad5cf PH |
696 | else if (errno == ENOENT) |
697 | { | |
17c76198 | 698 | rc = -1; |
182ad5cf | 699 | DEBUG(D_tls) |
17c76198 | 700 | debug_printf("D-H parameter cache file \"%s\" does not exist\n", filename); |
182ad5cf PH |
701 | } |
702 | else | |
17c76198 | 703 | return tls_error(string_open_failed(errno, "\"%s\" for reading", filename), |
cf0c6164 | 704 | NULL, NULL, errstr); |
b5aea5e1 PH |
705 | |
706 | /* If ret < 0, either the cache file does not exist, or the data it contains | |
707 | is not useful. One particular case of this is when upgrading from an older | |
708 | release of Exim in which the data was stored in a different format. We don't | |
709 | try to be clever and support both formats; we just regenerate new data in this | |
710 | case. */ | |
711 | ||
17c76198 | 712 | if (rc < 0) |
b5aea5e1 | 713 | { |
17c76198 | 714 | uschar *temp_fn; |
201f5254 | 715 | unsigned int dh_bits_gen = dh_bits; |
059ec3d9 | 716 | |
17c76198 PP |
717 | if ((PATH_MAX - Ustrlen(filename)) < 10) |
718 | return tls_error(US"Filename too long to generate replacement", | |
48224640 | 719 | filename, NULL, errstr); |
059ec3d9 | 720 | |
48224640 | 721 | temp_fn = string_copy(US"%s.XXXXXXX"); |
f5d25c2b | 722 | if ((fd = mkstemp(CS temp_fn)) < 0) /* modifies temp_fn */ |
452a164f | 723 | return tls_error_sys(US"Unable to open temp file", errno, NULL, errstr); |
b66fecb4 | 724 | (void)exim_chown(temp_fn, exim_uid, exim_gid); /* Probably not necessary */ |
059ec3d9 | 725 | |
49132a3b JH |
726 | /* GnuTLS overshoots! If we ask for 2236, we might get 2237 or more. But |
727 | there's no way to ask GnuTLS how many bits there really are. We can ask | |
728 | how many bits were used in a TLS session, but that's it! The prime itself | |
729 | is hidden behind too much abstraction. So we ask for less, and proceed on | |
730 | a wing and a prayer. First attempt, subtracted 3 for 2233 and got 2240. */ | |
731 | ||
cae6e576 | 732 | if (dh_bits >= EXIM_CLIENT_DH_MIN_BITS + 10) |
201f5254 PP |
733 | { |
734 | dh_bits_gen = dh_bits - 10; | |
735 | DEBUG(D_tls) | |
736 | debug_printf("being paranoid about DH generation, make it '%d' bits'\n", | |
737 | dh_bits_gen); | |
738 | } | |
739 | ||
740 | DEBUG(D_tls) | |
741 | debug_printf("requesting generation of %d bit Diffie-Hellman prime ...\n", | |
742 | dh_bits_gen); | |
452a164f JH |
743 | if ((rc = gnutls_dh_params_generate2(dh_server_params, dh_bits_gen))) |
744 | return tls_error_gnu(US"gnutls_dh_params_generate2", rc, host, errstr); | |
17c76198 PP |
745 | |
746 | /* gnutls_dh_params_export_pkcs3() will tell us the exact size, every time, | |
747 | and I confirmed that a NULL call to get the size first is how the GnuTLS | |
748 | sample apps handle this. */ | |
749 | ||
750 | sz = 0; | |
751 | m.data = NULL; | |
452a164f JH |
752 | if ( (rc = gnutls_dh_params_export_pkcs3(dh_server_params, |
753 | GNUTLS_X509_FMT_PEM, m.data, &sz)) | |
754 | && rc != GNUTLS_E_SHORT_MEMORY_BUFFER) | |
755 | return tls_error_gnu(US"gnutls_dh_params_export_pkcs3(NULL) sizing", | |
756 | rc, host, errstr); | |
17c76198 | 757 | m.size = sz; |
f3ebb786 | 758 | if (!(m.data = store_malloc(m.size))) |
452a164f | 759 | return tls_error_sys(US"memory allocation failed", errno, NULL, errstr); |
40c90bca | 760 | |
1f00591e | 761 | /* this will return a size 1 less than the allocation size above */ |
452a164f JH |
762 | if ((rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, |
763 | m.data, &sz))) | |
17c76198 | 764 | { |
f3ebb786 | 765 | store_free(m.data); |
452a164f | 766 | return tls_error_gnu(US"gnutls_dh_params_export_pkcs3() real", rc, host, errstr); |
17c76198 | 767 | } |
1f00591e | 768 | m.size = sz; /* shrink by 1, probably */ |
059ec3d9 | 769 | |
f5d25c2b | 770 | if ((sz = write_to_fd_buf(fd, m.data, (size_t) m.size)) != m.size) |
17c76198 | 771 | { |
f3ebb786 | 772 | store_free(m.data); |
452a164f JH |
773 | return tls_error_sys(US"TLS cache write D-H params failed", |
774 | errno, NULL, errstr); | |
17c76198 | 775 | } |
f3ebb786 | 776 | store_free(m.data); |
f5d25c2b | 777 | if ((sz = write_to_fd_buf(fd, US"\n", 1)) != 1) |
452a164f JH |
778 | return tls_error_sys(US"TLS cache write D-H params final newline failed", |
779 | errno, NULL, errstr); | |
17c76198 | 780 | |
f5d25c2b | 781 | if ((rc = close(fd))) |
452a164f | 782 | return tls_error_sys(US"TLS cache write close() failed", errno, NULL, errstr); |
059ec3d9 | 783 | |
17c76198 | 784 | if (Urename(temp_fn, filename) < 0) |
452a164f JH |
785 | return tls_error_sys(string_sprintf("failed to rename \"%s\" as \"%s\"", |
786 | temp_fn, filename), errno, NULL, errstr); | |
059ec3d9 | 787 | |
17c76198 | 788 | DEBUG(D_tls) debug_printf("wrote D-H parameters to file \"%s\"\n", filename); |
059ec3d9 PH |
789 | } |
790 | ||
17c76198 | 791 | DEBUG(D_tls) debug_printf("initialized server D-H parameters\n"); |
059ec3d9 PH |
792 | return OK; |
793 | } | |
49132a3b | 794 | #endif |
059ec3d9 PH |
795 | |
796 | ||
797 | ||
798 | ||
23bb6982 JH |
799 | /* Create and install a selfsigned certificate, for use in server mode */ |
800 | ||
801 | static int | |
cf0c6164 | 802 | tls_install_selfsign(exim_gnutls_state_st * state, uschar ** errstr) |
23bb6982 JH |
803 | { |
804 | gnutls_x509_crt_t cert = NULL; | |
805 | time_t now; | |
806 | gnutls_x509_privkey_t pkey = NULL; | |
807 | const uschar * where; | |
808 | int rc; | |
809 | ||
810 | where = US"initialising pkey"; | |
811 | if ((rc = gnutls_x509_privkey_init(&pkey))) goto err; | |
812 | ||
813 | where = US"initialising cert"; | |
814 | if ((rc = gnutls_x509_crt_init(&cert))) goto err; | |
815 | ||
816 | where = US"generating pkey"; | |
817 | if ((rc = gnutls_x509_privkey_generate(pkey, GNUTLS_PK_RSA, | |
76075bb5 | 818 | #ifdef SUPPORT_PARAM_TO_PK_BITS |
4312da48 JH |
819 | # ifndef GNUTLS_SEC_PARAM_MEDIUM |
820 | # define GNUTLS_SEC_PARAM_MEDIUM GNUTLS_SEC_PARAM_HIGH | |
821 | # endif | |
6aac3239 | 822 | gnutls_sec_param_to_pk_bits(GNUTLS_PK_RSA, GNUTLS_SEC_PARAM_MEDIUM), |
76075bb5 | 823 | #else |
6aac3239 | 824 | 2048, |
76075bb5 JH |
825 | #endif |
826 | 0))) | |
23bb6982 JH |
827 | goto err; |
828 | ||
829 | where = US"configuring cert"; | |
1613fd68 | 830 | now = 1; |
23bb6982 JH |
831 | if ( (rc = gnutls_x509_crt_set_version(cert, 3)) |
832 | || (rc = gnutls_x509_crt_set_serial(cert, &now, sizeof(now))) | |
833 | || (rc = gnutls_x509_crt_set_activation_time(cert, now = time(NULL))) | |
834 | || (rc = gnutls_x509_crt_set_expiration_time(cert, now + 60 * 60)) /* 1 hr */ | |
835 | || (rc = gnutls_x509_crt_set_key(cert, pkey)) | |
836 | ||
837 | || (rc = gnutls_x509_crt_set_dn_by_oid(cert, | |
838 | GNUTLS_OID_X520_COUNTRY_NAME, 0, "UK", 2)) | |
839 | || (rc = gnutls_x509_crt_set_dn_by_oid(cert, | |
840 | GNUTLS_OID_X520_ORGANIZATION_NAME, 0, "Exim Developers", 15)) | |
841 | || (rc = gnutls_x509_crt_set_dn_by_oid(cert, | |
842 | GNUTLS_OID_X520_COMMON_NAME, 0, | |
843 | smtp_active_hostname, Ustrlen(smtp_active_hostname))) | |
844 | ) | |
845 | goto err; | |
846 | ||
847 | where = US"signing cert"; | |
848 | if ((rc = gnutls_x509_crt_sign(cert, cert, pkey))) goto err; | |
849 | ||
850 | where = US"installing selfsign cert"; | |
851 | /* Since: 2.4.0 */ | |
852 | if ((rc = gnutls_certificate_set_x509_key(state->x509_cred, &cert, 1, pkey))) | |
853 | goto err; | |
854 | ||
855 | rc = OK; | |
856 | ||
857 | out: | |
858 | if (cert) gnutls_x509_crt_deinit(cert); | |
859 | if (pkey) gnutls_x509_privkey_deinit(pkey); | |
860 | return rc; | |
861 | ||
862 | err: | |
452a164f | 863 | rc = tls_error_gnu(where, rc, NULL, errstr); |
23bb6982 JH |
864 | goto out; |
865 | } | |
866 | ||
867 | ||
868 | ||
869 | ||
47195144 JH |
870 | /* Add certificate and key, from files. |
871 | ||
872 | Return: | |
873 | Zero or negative: good. Negate value for certificate index if < 0. | |
874 | Greater than zero: FAIL or DEFER code. | |
875 | */ | |
876 | ||
ba86e143 JH |
877 | static int |
878 | tls_add_certfile(exim_gnutls_state_st * state, const host_item * host, | |
879 | uschar * certfile, uschar * keyfile, uschar ** errstr) | |
880 | { | |
881 | int rc = gnutls_certificate_set_x509_key_file(state->x509_cred, | |
882 | CS certfile, CS keyfile, GNUTLS_X509_FMT_PEM); | |
47195144 | 883 | if (rc < 0) |
452a164f | 884 | return tls_error_gnu( |
47195144 | 885 | string_sprintf("cert/key setup: cert=%s key=%s", certfile, keyfile), |
452a164f | 886 | rc, host, errstr); |
47195144 | 887 | return -rc; |
ba86e143 JH |
888 | } |
889 | ||
890 | ||
d896cef5 JH |
891 | #if !defined(DISABLE_OCSP) && !defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) |
892 | /* Load an OCSP proof from file for sending by the server. Called | |
893 | on getting a status-request handshake message, for earlier versions | |
894 | of GnuTLS. */ | |
895 | ||
896 | static int | |
897 | server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, | |
898 | gnutls_datum_t * ocsp_response) | |
899 | { | |
900 | int ret; | |
901 | DEBUG(D_tls) debug_printf("OCSP stapling callback: %s\n", US ptr); | |
902 | ||
903 | if ((ret = gnutls_load_file(ptr, ocsp_response)) < 0) | |
904 | { | |
905 | DEBUG(D_tls) debug_printf("Failed to load ocsp stapling file %s\n", | |
906 | CS ptr); | |
907 | tls_in.ocsp = OCSP_NOT_RESP; | |
908 | return GNUTLS_E_NO_CERTIFICATE_STATUS; | |
909 | } | |
910 | ||
911 | tls_in.ocsp = OCSP_VFY_NOT_TRIED; | |
912 | return 0; | |
913 | } | |
914 | #endif | |
915 | ||
916 | ||
be427508 | 917 | #ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE |
e5489333 JH |
918 | /* Make a note that we saw a status-request */ |
919 | static int | |
920 | tls_server_clienthello_ext(void * ctx, unsigned tls_id, | |
921 | const unsigned char *data, unsigned size) | |
922 | { | |
923 | /* https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */ | |
924 | if (tls_id == 5) /* status_request */ | |
925 | { | |
e326959e | 926 | DEBUG(D_tls) debug_printf("Seen status_request extension from client\n"); |
e5489333 JH |
927 | tls_in.ocsp = OCSP_NOT_RESP; |
928 | } | |
929 | return 0; | |
930 | } | |
931 | ||
932 | /* Callback for client-hello, on server, if we think we might serve stapled-OCSP */ | |
933 | static int | |
934 | tls_server_clienthello_cb(gnutls_session_t session, unsigned int htype, | |
935 | unsigned when, unsigned int incoming, const gnutls_datum_t * msg) | |
936 | { | |
937 | /* Call fn for each extension seen. 3.6.3 onwards */ | |
938 | return gnutls_ext_raw_parse(NULL, tls_server_clienthello_ext, msg, | |
939 | GNUTLS_EXT_RAW_FLAG_TLS_CLIENT_HELLO); | |
940 | } | |
e326959e JH |
941 | |
942 | ||
943 | /* Make a note that we saw a status-response */ | |
944 | static int | |
945 | tls_server_servercerts_ext(void * ctx, unsigned tls_id, | |
946 | const unsigned char *data, unsigned size) | |
947 | { | |
948 | /* debug_printf("%s %u\n", __FUNCTION__, tls_id); */ | |
949 | /* https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */ | |
950 | if (FALSE && tls_id == 5) /* status_request */ | |
951 | { | |
952 | DEBUG(D_tls) debug_printf("Seen status_request extension\n"); | |
953 | tls_in.ocsp = exim_testharness_disable_ocsp_validity_check | |
954 | ? OCSP_VFY_NOT_TRIED : OCSP_VFIED; /* We know that GnuTLS verifies responses */ | |
955 | } | |
956 | return 0; | |
957 | } | |
958 | ||
959 | /* Callback for certificates packet, on server, if we think we might serve stapled-OCSP */ | |
960 | static int | |
961 | tls_server_servercerts_cb(gnutls_session_t session, unsigned int htype, | |
962 | unsigned when, unsigned int incoming, const gnutls_datum_t * msg) | |
963 | { | |
964 | /* Call fn for each extension seen. 3.6.3 onwards */ | |
965 | #ifdef notdef | |
966 | /*XXX crashes */ | |
967 | return gnutls_ext_raw_parse(NULL, tls_server_servercerts_ext, msg, 0); | |
968 | #endif | |
969 | } | |
be427508 | 970 | #endif |
e5489333 | 971 | |
e326959e JH |
972 | /*XXX in tls1.3 the cert-status travel as an extension next to the cert, in the |
973 | "Handshake Protocol: Certificate" record. | |
974 | So we need to spot the Certificate handshake message, parse it and spot any status_request extension(s) | |
975 | ||
976 | This is different to tls1.2 - where it is a separate record (wireshake term) / handshake message (gnutls term). | |
977 | */ | |
978 | ||
727a5d25 | 979 | #if defined(EXPERIMENTAL_TLS_RESUME) || defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) |
e5489333 JH |
980 | /* Callback for certificate-status, on server. We sent stapled OCSP. */ |
981 | static int | |
982 | tls_server_certstatus_cb(gnutls_session_t session, unsigned int htype, | |
983 | unsigned when, unsigned int incoming, const gnutls_datum_t * msg) | |
984 | { | |
e326959e | 985 | DEBUG(D_tls) debug_printf("Sending certificate-status\n"); /*XXX we get this for tls1.2 but not for 1.3 */ |
e5489333 JH |
986 | #ifdef SUPPORT_SRV_OCSP_STACK |
987 | tls_in.ocsp = exim_testharness_disable_ocsp_validity_check | |
988 | ? OCSP_VFY_NOT_TRIED : OCSP_VFIED; /* We know that GnuTLS verifies responses */ | |
989 | #else | |
990 | tls_in.ocsp = OCSP_VFY_NOT_TRIED; | |
991 | #endif | |
992 | return 0; | |
993 | } | |
994 | ||
995 | /* Callback for handshake messages, on server */ | |
996 | static int | |
997 | tls_server_hook_cb(gnutls_session_t sess, u_int htype, unsigned when, | |
998 | unsigned incoming, const gnutls_datum_t * msg) | |
999 | { | |
e326959e | 1000 | /* debug_printf("%s: htype %u\n", __FUNCTION__, htype); */ |
e5489333 JH |
1001 | switch (htype) |
1002 | { | |
727a5d25 | 1003 | # ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE |
e5489333 JH |
1004 | case GNUTLS_HANDSHAKE_CLIENT_HELLO: |
1005 | return tls_server_clienthello_cb(sess, htype, when, incoming, msg); | |
e326959e JH |
1006 | case GNUTLS_HANDSHAKE_CERTIFICATE_PKT: |
1007 | return tls_server_servercerts_cb(sess, htype, when, incoming, msg); | |
727a5d25 | 1008 | # endif |
e5489333 JH |
1009 | case GNUTLS_HANDSHAKE_CERTIFICATE_STATUS: |
1010 | return tls_server_certstatus_cb(sess, htype, when, incoming, msg); | |
727a5d25 | 1011 | # ifdef EXPERIMENTAL_TLS_RESUME |
e5489333 JH |
1012 | case GNUTLS_HANDSHAKE_NEW_SESSION_TICKET: |
1013 | return tls_server_ticket_cb(sess, htype, when, incoming, msg); | |
727a5d25 | 1014 | # endif |
e5489333 JH |
1015 | default: |
1016 | return 0; | |
1017 | } | |
1018 | } | |
727a5d25 | 1019 | #endif |
e5489333 JH |
1020 | |
1021 | ||
727a5d25 | 1022 | #if !defined(DISABLE_OCSP) && defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) |
e5489333 JH |
1023 | static void |
1024 | tls_server_testharness_ocsp_fiddle(void) | |
1025 | { | |
1026 | extern char ** environ; | |
1027 | if (environ) for (uschar ** p = USS environ; *p; p++) | |
1028 | if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) | |
1029 | { | |
1030 | DEBUG(D_tls) debug_printf("Permitting known bad OCSP response\n"); | |
1031 | exim_testharness_disable_ocsp_validity_check = TRUE; | |
1032 | } | |
1033 | } | |
727a5d25 | 1034 | #endif |
e5489333 | 1035 | |
059ec3d9 | 1036 | /************************************************* |
17c76198 | 1037 | * Variables re-expanded post-SNI * |
059ec3d9 PH |
1038 | *************************************************/ |
1039 | ||
17c76198 PP |
1040 | /* Called from both server and client code, via tls_init(), and also from |
1041 | the SNI callback after receiving an SNI, if tls_certificate includes "tls_sni". | |
1042 | ||
1043 | We can tell the two apart by state->received_sni being non-NULL in callback. | |
1044 | ||
1045 | The callback should not call us unless state->trigger_sni_changes is true, | |
1046 | which we are responsible for setting on the first pass through. | |
059ec3d9 PH |
1047 | |
1048 | Arguments: | |
17c76198 | 1049 | state exim_gnutls_state_st * |
cf0c6164 | 1050 | errstr error string pointer |
059ec3d9 PH |
1051 | |
1052 | Returns: OK/DEFER/FAIL | |
1053 | */ | |
1054 | ||
1055 | static int | |
ba86e143 | 1056 | tls_expand_session_files(exim_gnutls_state_st * state, uschar ** errstr) |
059ec3d9 | 1057 | { |
1365611d | 1058 | struct stat statbuf; |
059ec3d9 | 1059 | int rc; |
17c76198 PP |
1060 | const host_item *host = state->host; /* macro should be reconsidered? */ |
1061 | uschar *saved_tls_certificate = NULL; | |
1062 | uschar *saved_tls_privatekey = NULL; | |
1063 | uschar *saved_tls_verify_certificates = NULL; | |
1064 | uschar *saved_tls_crl = NULL; | |
1065 | int cert_count; | |
1066 | ||
1067 | /* We check for tls_sni *before* expansion. */ | |
2b4a568d | 1068 | if (!host) /* server */ |
17c76198 PP |
1069 | if (!state->received_sni) |
1070 | { | |
ba86e143 JH |
1071 | if ( state->tls_certificate |
1072 | && ( Ustrstr(state->tls_certificate, US"tls_sni") | |
1073 | || Ustrstr(state->tls_certificate, US"tls_in_sni") | |
1074 | || Ustrstr(state->tls_certificate, US"tls_out_sni") | |
1075 | ) ) | |
17c76198 PP |
1076 | { |
1077 | DEBUG(D_tls) debug_printf("We will re-expand TLS session files if we receive SNI.\n"); | |
1078 | state->trigger_sni_changes = TRUE; | |
1079 | } | |
1080 | } | |
1081 | else | |
1082 | { | |
1365611d | 1083 | /* useful for debugging */ |
17c76198 PP |
1084 | saved_tls_certificate = state->exp_tls_certificate; |
1085 | saved_tls_privatekey = state->exp_tls_privatekey; | |
1086 | saved_tls_verify_certificates = state->exp_tls_verify_certificates; | |
1087 | saved_tls_crl = state->exp_tls_crl; | |
1088 | } | |
059ec3d9 | 1089 | |
452a164f JH |
1090 | if ((rc = gnutls_certificate_allocate_credentials(&state->x509_cred))) |
1091 | return tls_error_gnu(US"gnutls_certificate_allocate_credentials", | |
1092 | rc, host, errstr); | |
47195144 JH |
1093 | |
1094 | #ifdef SUPPORT_SRV_OCSP_STACK | |
1095 | gnutls_certificate_set_flags(state->x509_cred, GNUTLS_CERTIFICATE_API_V2); | |
e326959e JH |
1096 | |
1097 | # if !defined(DISABLE_OCSP) && defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) | |
1098 | if (!host && tls_ocsp_file) | |
1099 | { | |
1100 | if (f.running_in_test_harness) | |
1101 | tls_server_testharness_ocsp_fiddle(); | |
1102 | ||
1103 | if (exim_testharness_disable_ocsp_validity_check) | |
1104 | gnutls_certificate_set_flags(state->x509_cred, | |
1105 | GNUTLS_CERTIFICATE_API_V2 | GNUTLS_CERTIFICATE_SKIP_OCSP_RESPONSE_CHECK); | |
1106 | } | |
1107 | # endif | |
47195144 | 1108 | #endif |
1365611d | 1109 | |
17c76198 PP |
1110 | /* remember: expand_check_tlsvar() is expand_check() but fiddling with |
1111 | state members, assuming consistent naming; and expand_check() returns | |
1112 | false if expansion failed, unless expansion was forced to fail. */ | |
059ec3d9 | 1113 | |
17c76198 PP |
1114 | /* check if we at least have a certificate, before doing expensive |
1115 | D-H generation. */ | |
059ec3d9 | 1116 | |
cf0c6164 | 1117 | if (!expand_check_tlsvar(tls_certificate, errstr)) |
17c76198 | 1118 | return DEFER; |
059ec3d9 | 1119 | |
17c76198 | 1120 | /* certificate is mandatory in server, optional in client */ |
059ec3d9 | 1121 | |
23bb6982 JH |
1122 | if ( !state->exp_tls_certificate |
1123 | || !*state->exp_tls_certificate | |
1124 | ) | |
2b4a568d | 1125 | if (!host) |
cf0c6164 | 1126 | return tls_install_selfsign(state, errstr); |
17c76198 PP |
1127 | else |
1128 | DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n"); | |
059ec3d9 | 1129 | |
cf0c6164 | 1130 | if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey, errstr)) |
059ec3d9 PH |
1131 | return DEFER; |
1132 | ||
17c76198 PP |
1133 | /* tls_privatekey is optional, defaulting to same file as certificate */ |
1134 | ||
e326959e | 1135 | if (!state->tls_privatekey || !*state->tls_privatekey) |
059ec3d9 | 1136 | { |
17c76198 PP |
1137 | state->tls_privatekey = state->tls_certificate; |
1138 | state->exp_tls_privatekey = state->exp_tls_certificate; | |
059ec3d9 | 1139 | } |
c91535f3 | 1140 | |
059ec3d9 | 1141 | |
17c76198 | 1142 | if (state->exp_tls_certificate && *state->exp_tls_certificate) |
059ec3d9 PH |
1143 | { |
1144 | DEBUG(D_tls) debug_printf("certificate file = %s\nkey file = %s\n", | |
17c76198 PP |
1145 | state->exp_tls_certificate, state->exp_tls_privatekey); |
1146 | ||
1147 | if (state->received_sni) | |
23bb6982 JH |
1148 | if ( Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0 |
1149 | && Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0 | |
1150 | ) | |
17c76198 | 1151 | { |
b34fc30c | 1152 | DEBUG(D_tls) debug_printf("TLS SNI: cert and key unchanged\n"); |
17c76198 PP |
1153 | } |
1154 | else | |
1155 | { | |
b34fc30c | 1156 | DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair.\n"); |
17c76198 | 1157 | } |
059ec3d9 | 1158 | |
ba86e143 JH |
1159 | if (!host) /* server */ |
1160 | { | |
1161 | const uschar * clist = state->exp_tls_certificate; | |
1162 | const uschar * klist = state->exp_tls_privatekey; | |
47195144 JH |
1163 | const uschar * olist; |
1164 | int csep = 0, ksep = 0, osep = 0, cnt = 0; | |
1165 | uschar * cfile, * kfile, * ofile; | |
47195144 | 1166 | #ifndef DISABLE_OCSP |
e326959e JH |
1167 | # ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE |
1168 | gnutls_x509_crt_fmt_t ocsp_fmt = GNUTLS_X509_FMT_DER; | |
1169 | # endif | |
1170 | ||
47195144 JH |
1171 | if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", &ofile, errstr)) |
1172 | return DEFER; | |
1173 | olist = ofile; | |
1174 | #endif | |
ba86e143 JH |
1175 | |
1176 | while (cfile = string_nextinlist(&clist, &csep, NULL, 0)) | |
47195144 | 1177 | |
ba86e143 JH |
1178 | if (!(kfile = string_nextinlist(&klist, &ksep, NULL, 0))) |
1179 | return tls_error(US"cert/key setup: out of keys", NULL, host, errstr); | |
47195144 | 1180 | else if (0 < (rc = tls_add_certfile(state, host, cfile, kfile, errstr))) |
ba86e143 JH |
1181 | return rc; |
1182 | else | |
47195144 JH |
1183 | { |
1184 | int gnutls_cert_index = -rc; | |
e326959e JH |
1185 | DEBUG(D_tls) debug_printf("TLS: cert/key %d %s registered\n", |
1186 | gnutls_cert_index, cfile); | |
47195144 JH |
1187 | |
1188 | #ifndef DISABLE_OCSP | |
1189 | if (tls_ocsp_file) | |
e5489333 | 1190 | { |
e326959e | 1191 | /* Set the OCSP stapling server info */ |
47195144 JH |
1192 | if (gnutls_buggy_ocsp) |
1193 | { | |
1194 | DEBUG(D_tls) | |
1195 | debug_printf("GnuTLS library is buggy for OCSP; avoiding\n"); | |
1196 | } | |
1197 | else if ((ofile = string_nextinlist(&olist, &osep, NULL, 0))) | |
1198 | { | |
e326959e JH |
1199 | DEBUG(D_tls) debug_printf("OCSP response file %d = %s\n", |
1200 | gnutls_cert_index, ofile); | |
be427508 | 1201 | # ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE |
e326959e | 1202 | if (Ustrncmp(ofile, US"PEM ", 4) == 0) |
47195144 | 1203 | { |
e326959e JH |
1204 | ocsp_fmt = GNUTLS_X509_FMT_PEM; |
1205 | ofile += 4; | |
1206 | } | |
1207 | else if (Ustrncmp(ofile, US"DER ", 4) == 0) | |
1208 | { | |
1209 | ocsp_fmt = GNUTLS_X509_FMT_DER; | |
1210 | ofile += 4; | |
1211 | } | |
e5489333 | 1212 | |
e326959e JH |
1213 | if ((rc = gnutls_certificate_set_ocsp_status_request_file2( |
1214 | state->x509_cred, CCS ofile, gnutls_cert_index, | |
1215 | ocsp_fmt)) < 0) | |
1216 | return tls_error_gnu( | |
1217 | US"gnutls_certificate_set_ocsp_status_request_file2", | |
1218 | rc, host, errstr); | |
1219 | DEBUG(D_tls) | |
1220 | debug_printf(" %d response%s loaded\n", rc, rc>1 ? "s":""); | |
e5489333 | 1221 | |
e326959e JH |
1222 | /* Arrange callbacks for OCSP request observability */ |
1223 | ||
1224 | gnutls_handshake_set_hook_function(state->session, | |
1225 | GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb); | |
1226 | ||
1227 | # else | |
1228 | # if defined(SUPPORT_SRV_OCSP_STACK) | |
be427508 JH |
1229 | if ((rc = gnutls_certificate_set_ocsp_status_request_function2( |
1230 | state->x509_cred, gnutls_cert_index, | |
1231 | server_ocsp_stapling_cb, ofile))) | |
1232 | return tls_error_gnu( | |
1233 | US"gnutls_certificate_set_ocsp_status_request_function2", | |
1234 | rc, host, errstr); | |
1235 | else | |
e326959e | 1236 | # endif |
e5489333 JH |
1237 | { |
1238 | if (cnt++ > 0) | |
1239 | { | |
1240 | DEBUG(D_tls) | |
1241 | debug_printf("oops; multiple OCSP files not supported\n"); | |
1242 | break; | |
1243 | } | |
d896cef5 JH |
1244 | gnutls_certificate_set_ocsp_status_request_function( |
1245 | state->x509_cred, server_ocsp_stapling_cb, ofile); | |
e5489333 | 1246 | } |
e326959e | 1247 | # endif /* SUPPORT_GNUTLS_EXT_RAW_PARSE */ |
47195144 JH |
1248 | } |
1249 | else | |
1250 | DEBUG(D_tls) debug_printf("ran out of OCSP response files in list\n"); | |
e5489333 | 1251 | } |
fd71e7b8 | 1252 | #endif /* DISABLE_OCSP */ |
47195144 | 1253 | } |
ba86e143 | 1254 | } |
e5489333 | 1255 | else /* client */ |
ba86e143 | 1256 | { |
47195144 | 1257 | if (0 < (rc = tls_add_certfile(state, host, |
ba86e143 JH |
1258 | state->exp_tls_certificate, state->exp_tls_privatekey, errstr))) |
1259 | return rc; | |
1260 | DEBUG(D_tls) debug_printf("TLS: cert/key registered\n"); | |
1261 | } | |
1262 | ||
b34fc30c | 1263 | } /* tls_certificate */ |
059ec3d9 | 1264 | |
2b4a568d | 1265 | |
059ec3d9 PH |
1266 | /* Set the trusted CAs file if one is provided, and then add the CRL if one is |
1267 | provided. Experiment shows that, if the certificate file is empty, an unhelpful | |
1268 | error message is provided. However, if we just refrain from setting anything up | |
1269 | in that case, certificate verification fails, which seems to be the correct | |
1270 | behaviour. */ | |
1271 | ||
610ff438 | 1272 | if (state->tls_verify_certificates && *state->tls_verify_certificates) |
059ec3d9 | 1273 | { |
cf0c6164 | 1274 | if (!expand_check_tlsvar(tls_verify_certificates, errstr)) |
059ec3d9 | 1275 | return DEFER; |
610ff438 JH |
1276 | #ifndef SUPPORT_SYSDEFAULT_CABUNDLE |
1277 | if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) | |
1278 | state->exp_tls_verify_certificates = NULL; | |
1279 | #endif | |
17c76198 | 1280 | if (state->tls_crl && *state->tls_crl) |
cf0c6164 | 1281 | if (!expand_check_tlsvar(tls_crl, errstr)) |
17c76198 | 1282 | return DEFER; |
059ec3d9 | 1283 | |
1365611d PP |
1284 | if (!(state->exp_tls_verify_certificates && |
1285 | *state->exp_tls_verify_certificates)) | |
b34fc30c PP |
1286 | { |
1287 | DEBUG(D_tls) | |
1365611d PP |
1288 | debug_printf("TLS: tls_verify_certificates expanded empty, ignoring\n"); |
1289 | /* With no tls_verify_certificates, we ignore tls_crl too */ | |
17c76198 | 1290 | return OK; |
b34fc30c | 1291 | } |
1365611d | 1292 | } |
83e2f8a2 PP |
1293 | else |
1294 | { | |
1295 | DEBUG(D_tls) | |
1296 | debug_printf("TLS: tls_verify_certificates not set or empty, ignoring\n"); | |
1297 | return OK; | |
1298 | } | |
17c76198 | 1299 | |
cb1d7830 JH |
1300 | #ifdef SUPPORT_SYSDEFAULT_CABUNDLE |
1301 | if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) | |
1302 | cert_count = gnutls_certificate_set_x509_system_trust(state->x509_cred); | |
1303 | else | |
1304 | #endif | |
1365611d | 1305 | { |
cb1d7830 JH |
1306 | if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0) |
1307 | { | |
d896cef5 | 1308 | log_write(0, LOG_MAIN|LOG_PANIC, "could not stat '%s' " |
cb1d7830 JH |
1309 | "(tls_verify_certificates): %s", state->exp_tls_verify_certificates, |
1310 | strerror(errno)); | |
1311 | return DEFER; | |
1312 | } | |
17c76198 | 1313 | |
a7fec7a7 | 1314 | #ifndef SUPPORT_CA_DIR |
cb1d7830 JH |
1315 | /* The test suite passes in /dev/null; we could check for that path explicitly, |
1316 | but who knows if someone has some weird FIFO which always dumps some certs, or | |
1317 | other weirdness. The thing we really want to check is that it's not a | |
1318 | directory, since while OpenSSL supports that, GnuTLS does not. | |
60f914bc | 1319 | So s/!S_ISREG/S_ISDIR/ and change some messaging ... */ |
cb1d7830 JH |
1320 | if (S_ISDIR(statbuf.st_mode)) |
1321 | { | |
1322 | DEBUG(D_tls) | |
1323 | debug_printf("verify certificates path is a dir: \"%s\"\n", | |
1324 | state->exp_tls_verify_certificates); | |
1325 | log_write(0, LOG_MAIN|LOG_PANIC, | |
1326 | "tls_verify_certificates \"%s\" is a directory", | |
1327 | state->exp_tls_verify_certificates); | |
1328 | return DEFER; | |
1329 | } | |
a7fec7a7 | 1330 | #endif |
059ec3d9 | 1331 | |
cb1d7830 JH |
1332 | DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n", |
1333 | state->exp_tls_verify_certificates, statbuf.st_size); | |
059ec3d9 | 1334 | |
cb1d7830 JH |
1335 | if (statbuf.st_size == 0) |
1336 | { | |
1337 | DEBUG(D_tls) | |
1338 | debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n"); | |
1339 | return OK; | |
1340 | } | |
059ec3d9 | 1341 | |
cb1d7830 | 1342 | cert_count = |
a7fec7a7 JH |
1343 | |
1344 | #ifdef SUPPORT_CA_DIR | |
cb1d7830 JH |
1345 | (statbuf.st_mode & S_IFMT) == S_IFDIR |
1346 | ? | |
1347 | gnutls_certificate_set_x509_trust_dir(state->x509_cred, | |
1348 | CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM) | |
1349 | : | |
a7fec7a7 | 1350 | #endif |
cb1d7830 JH |
1351 | gnutls_certificate_set_x509_trust_file(state->x509_cred, |
1352 | CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM); | |
12d95aa6 JH |
1353 | |
1354 | #ifdef SUPPORT_CA_DIR | |
1355 | /* Mimic the behaviour with OpenSSL of not advertising a usable-cert list | |
1356 | when using the directory-of-certs config model. */ | |
1357 | ||
1358 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
1359 | gnutls_certificate_send_x509_rdn_sequence(state->session, 1); | |
1360 | #endif | |
cb1d7830 | 1361 | } |
a7fec7a7 | 1362 | |
1365611d | 1363 | if (cert_count < 0) |
452a164f JH |
1364 | return tls_error_gnu(US"setting certificate trust", cert_count, host, errstr); |
1365 | DEBUG(D_tls) | |
1366 | debug_printf("Added %d certificate authorities.\n", cert_count); | |
059ec3d9 | 1367 | |
5c8cda3a PP |
1368 | if (state->tls_crl && *state->tls_crl && |
1369 | state->exp_tls_crl && *state->exp_tls_crl) | |
1365611d | 1370 | { |
5c8cda3a | 1371 | DEBUG(D_tls) debug_printf("loading CRL file = %s\n", state->exp_tls_crl); |
452a164f JH |
1372 | if ((cert_count = gnutls_certificate_set_x509_crl_file(state->x509_cred, |
1373 | CS state->exp_tls_crl, GNUTLS_X509_FMT_PEM)) < 0) | |
1374 | return tls_error_gnu(US"gnutls_certificate_set_x509_crl_file", | |
1375 | cert_count, host, errstr); | |
1376 | ||
5c8cda3a | 1377 | DEBUG(D_tls) debug_printf("Processed %d CRLs.\n", cert_count); |
1365611d | 1378 | } |
059ec3d9 | 1379 | |
059ec3d9 PH |
1380 | return OK; |
1381 | } | |
1382 | ||
1383 | ||
1384 | ||
1385 | ||
1365611d PP |
1386 | /************************************************* |
1387 | * Set X.509 state variables * | |
1388 | *************************************************/ | |
1389 | ||
1390 | /* In GnuTLS, the registered cert/key are not replaced by a later | |
1391 | set of a cert/key, so for SNI support we need a whole new x509_cred | |
1392 | structure. Which means various other non-re-expanded pieces of state | |
1393 | need to be re-set in the new struct, so the setting logic is pulled | |
1394 | out to this. | |
1395 | ||
1396 | Arguments: | |
1397 | state exim_gnutls_state_st * | |
cf0c6164 | 1398 | errstr error string pointer |
1365611d PP |
1399 | |
1400 | Returns: OK/DEFER/FAIL | |
1401 | */ | |
1402 | ||
1403 | static int | |
cf0c6164 | 1404 | tls_set_remaining_x509(exim_gnutls_state_st *state, uschar ** errstr) |
1365611d PP |
1405 | { |
1406 | int rc; | |
1407 | const host_item *host = state->host; /* macro should be reconsidered? */ | |
1408 | ||
49132a3b | 1409 | #ifndef GNUTLS_AUTO_DHPARAMS |
1365611d PP |
1410 | /* Create D-H parameters, or read them from the cache file. This function does |
1411 | its own SMTP error messaging. This only happens for the server, TLS D-H ignores | |
1412 | client-side params. */ | |
1413 | ||
1414 | if (!state->host) | |
1415 | { | |
1416 | if (!dh_server_params) | |
452a164f | 1417 | if ((rc = init_server_dh(errstr)) != OK) return rc; |
49132a3b JH |
1418 | |
1419 | /* Unnecessary & discouraged with 3.6.0 or later */ | |
1365611d PP |
1420 | gnutls_certificate_set_dh_params(state->x509_cred, dh_server_params); |
1421 | } | |
49132a3b | 1422 | #endif |
1365611d PP |
1423 | |
1424 | /* Link the credentials to the session. */ | |
1425 | ||
452a164f JH |
1426 | if ((rc = gnutls_credentials_set(state->session, |
1427 | GNUTLS_CRD_CERTIFICATE, state->x509_cred))) | |
1428 | return tls_error_gnu(US"gnutls_credentials_set", rc, host, errstr); | |
1365611d PP |
1429 | |
1430 | return OK; | |
1431 | } | |
1432 | ||
059ec3d9 | 1433 | /************************************************* |
17c76198 | 1434 | * Initialize for GnuTLS * |
059ec3d9 PH |
1435 | *************************************************/ |
1436 | ||
9196d5bf | 1437 | |
4fb7df6d JH |
1438 | #ifndef DISABLE_OCSP |
1439 | ||
9196d5bf JH |
1440 | static BOOL |
1441 | tls_is_buggy_ocsp(void) | |
1442 | { | |
1443 | const uschar * s; | |
1444 | uschar maj, mid, mic; | |
1445 | ||
1446 | s = CUS gnutls_check_version(NULL); | |
1447 | maj = atoi(CCS s); | |
1448 | if (maj == 3) | |
1449 | { | |
1450 | while (*s && *s != '.') s++; | |
1451 | mid = atoi(CCS ++s); | |
1452 | if (mid <= 2) | |
1453 | return TRUE; | |
1454 | else if (mid >= 5) | |
1455 | return FALSE; | |
1456 | else | |
1457 | { | |
1458 | while (*s && *s != '.') s++; | |
1459 | mic = atoi(CCS ++s); | |
1460 | return mic <= (mid == 3 ? 16 : 3); | |
1461 | } | |
1462 | } | |
1463 | return FALSE; | |
1464 | } | |
1465 | ||
4fb7df6d | 1466 | #endif |
9196d5bf JH |
1467 | |
1468 | ||
17c76198 PP |
1469 | /* Called from both server and client code. In the case of a server, errors |
1470 | before actual TLS negotiation return DEFER. | |
059ec3d9 PH |
1471 | |
1472 | Arguments: | |
17c76198 PP |
1473 | host connected host, if client; NULL if server |
1474 | certificate certificate file | |
1475 | privatekey private key file | |
1476 | sni TLS SNI to send, sometimes when client; else NULL | |
1477 | cas CA certs file | |
1478 | crl CRL file | |
1479 | require_ciphers tls_require_ciphers setting | |
817d9f57 | 1480 | caller_state returned state-info structure |
cf0c6164 | 1481 | errstr error string pointer |
059ec3d9 | 1482 | |
17c76198 | 1483 | Returns: OK/DEFER/FAIL |
059ec3d9 PH |
1484 | */ |
1485 | ||
17c76198 PP |
1486 | static int |
1487 | tls_init( | |
1488 | const host_item *host, | |
1489 | const uschar *certificate, | |
1490 | const uschar *privatekey, | |
1491 | const uschar *sni, | |
1492 | const uschar *cas, | |
1493 | const uschar *crl, | |
1494 | const uschar *require_ciphers, | |
cf0c6164 | 1495 | exim_gnutls_state_st **caller_state, |
74f1a423 | 1496 | tls_support * tlsp, |
cf0c6164 | 1497 | uschar ** errstr) |
059ec3d9 | 1498 | { |
00c0dd4e | 1499 | exim_gnutls_state_st * state; |
17c76198 PP |
1500 | int rc; |
1501 | size_t sz; | |
00c0dd4e JH |
1502 | const char * errpos; |
1503 | const uschar * p; | |
17c76198 PP |
1504 | |
1505 | if (!exim_gnutls_base_init_done) | |
059ec3d9 | 1506 | { |
17c76198 PP |
1507 | DEBUG(D_tls) debug_printf("GnuTLS global init required.\n"); |
1508 | ||
9f707b89 | 1509 | #if defined(HAVE_GNUTLS_PKCS11) && !defined(GNUTLS_AUTO_PKCS11_MANUAL) |
a5f239e4 PP |
1510 | /* By default, gnutls_global_init will init PKCS11 support in auto mode, |
1511 | which loads modules from a config file, which sounds good and may be wanted | |
1512 | by some sysadmin, but also means in common configurations that GNOME keyring | |
1513 | environment variables are used and so breaks for users calling mailq. | |
1514 | To prevent this, we init PKCS11 first, which is the documented approach. */ | |
2519e60d | 1515 | if (!gnutls_allow_auto_pkcs11) |
452a164f JH |
1516 | if ((rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL))) |
1517 | return tls_error_gnu(US"gnutls_pkcs11_init", rc, host, errstr); | |
a5f239e4 PP |
1518 | #endif |
1519 | ||
4d2a62a3 | 1520 | #ifndef GNUTLS_AUTO_GLOBAL_INIT |
452a164f JH |
1521 | if ((rc = gnutls_global_init())) |
1522 | return tls_error_gnu(US"gnutls_global_init", rc, host, errstr); | |
4d2a62a3 | 1523 | #endif |
17c76198 PP |
1524 | |
1525 | #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 | |
1526 | DEBUG(D_tls) | |
059ec3d9 | 1527 | { |
17c76198 | 1528 | gnutls_global_set_log_function(exim_gnutls_logger_cb); |
aded2255 | 1529 | /* arbitrarily chosen level; bump up to 9 for more */ |
17c76198 | 1530 | gnutls_global_set_log_level(EXIM_GNUTLS_LIBRARY_LOG_LEVEL); |
059ec3d9 | 1531 | } |
17c76198 PP |
1532 | #endif |
1533 | ||
4fb7df6d JH |
1534 | #ifndef DISABLE_OCSP |
1535 | if (tls_ocsp_file && (gnutls_buggy_ocsp = tls_is_buggy_ocsp())) | |
9196d5bf | 1536 | log_write(0, LOG_MAIN, "OCSP unusable with this GnuTLS library version"); |
4fb7df6d | 1537 | #endif |
9196d5bf | 1538 | |
17c76198 | 1539 | exim_gnutls_base_init_done = TRUE; |
059ec3d9 | 1540 | } |
059ec3d9 | 1541 | |
17c76198 PP |
1542 | if (host) |
1543 | { | |
74f1a423 JH |
1544 | /* For client-side sessions we allocate a context. This lets us run |
1545 | several in parallel. */ | |
1546 | int old_pool = store_pool; | |
1547 | store_pool = POOL_PERM; | |
f3ebb786 | 1548 | state = store_get(sizeof(exim_gnutls_state_st), FALSE); |
74f1a423 JH |
1549 | store_pool = old_pool; |
1550 | ||
17c76198 | 1551 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); |
74f1a423 | 1552 | state->tlsp = tlsp; |
17c76198 PP |
1553 | DEBUG(D_tls) debug_printf("initialising GnuTLS client session\n"); |
1554 | rc = gnutls_init(&state->session, GNUTLS_CLIENT); | |
1555 | } | |
1556 | else | |
1557 | { | |
1558 | state = &state_server; | |
1559 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); | |
74f1a423 | 1560 | state->tlsp = tlsp; |
17c76198 PP |
1561 | DEBUG(D_tls) debug_printf("initialising GnuTLS server session\n"); |
1562 | rc = gnutls_init(&state->session, GNUTLS_SERVER); | |
1563 | } | |
452a164f JH |
1564 | if (rc) |
1565 | return tls_error_gnu(US"gnutls_init", rc, host, errstr); | |
059ec3d9 | 1566 | |
17c76198 | 1567 | state->host = host; |
059ec3d9 | 1568 | |
17c76198 PP |
1569 | state->tls_certificate = certificate; |
1570 | state->tls_privatekey = privatekey; | |
5779e6aa | 1571 | state->tls_require_ciphers = require_ciphers; |
17c76198 PP |
1572 | state->tls_sni = sni; |
1573 | state->tls_verify_certificates = cas; | |
1574 | state->tls_crl = crl; | |
059ec3d9 | 1575 | |
17c76198 PP |
1576 | /* This handles the variables that might get re-expanded after TLS SNI; |
1577 | that's tls_certificate, tls_privatekey, tls_verify_certificates, tls_crl */ | |
059ec3d9 | 1578 | |
17c76198 PP |
1579 | DEBUG(D_tls) |
1580 | debug_printf("Expanding various TLS configuration options for session credentials.\n"); | |
cf0c6164 | 1581 | if ((rc = tls_expand_session_files(state, errstr)) != OK) return rc; |
059ec3d9 | 1582 | |
1365611d PP |
1583 | /* These are all other parts of the x509_cred handling, since SNI in GnuTLS |
1584 | requires a new structure afterwards. */ | |
83da1223 | 1585 | |
cf0c6164 | 1586 | if ((rc = tls_set_remaining_x509(state, errstr)) != OK) return rc; |
83da1223 | 1587 | |
17c76198 PP |
1588 | /* set SNI in client, only */ |
1589 | if (host) | |
1590 | { | |
cf0c6164 | 1591 | if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni, errstr)) |
17c76198 | 1592 | return DEFER; |
0df4ab80 | 1593 | if (state->tlsp->sni && *state->tlsp->sni) |
17c76198 PP |
1594 | { |
1595 | DEBUG(D_tls) | |
0df4ab80 JH |
1596 | debug_printf("Setting TLS client SNI to \"%s\"\n", state->tlsp->sni); |
1597 | sz = Ustrlen(state->tlsp->sni); | |
452a164f JH |
1598 | if ((rc = gnutls_server_name_set(state->session, |
1599 | GNUTLS_NAME_DNS, state->tlsp->sni, sz))) | |
1600 | return tls_error_gnu(US"gnutls_server_name_set", rc, host, errstr); | |
17c76198 PP |
1601 | } |
1602 | } | |
1603 | else if (state->tls_sni) | |
1604 | DEBUG(D_tls) debug_printf("*** PROBABLY A BUG *** " \ | |
ba86e143 | 1605 | "have an SNI set for a server [%s]\n", state->tls_sni); |
83da1223 | 1606 | |
17c76198 | 1607 | /* This is the priority string support, |
42bfef1e | 1608 | http://www.gnutls.org/manual/html_node/Priority-Strings.html |
17c76198 PP |
1609 | and replaces gnutls_require_kx, gnutls_require_mac & gnutls_require_protocols. |
1610 | This was backwards incompatible, but means Exim no longer needs to track | |
1611 | all algorithms and provide string forms for them. */ | |
83da1223 | 1612 | |
fc243e94 | 1613 | p = NULL; |
17c76198 | 1614 | if (state->tls_require_ciphers && *state->tls_require_ciphers) |
83da1223 | 1615 | { |
cf0c6164 | 1616 | if (!expand_check_tlsvar(tls_require_ciphers, errstr)) |
17c76198 PP |
1617 | return DEFER; |
1618 | if (state->exp_tls_require_ciphers && *state->exp_tls_require_ciphers) | |
83da1223 | 1619 | { |
17c76198 | 1620 | p = state->exp_tls_require_ciphers; |
fc243e94 | 1621 | DEBUG(D_tls) debug_printf("GnuTLS session cipher/priority \"%s\"\n", p); |
83da1223 PH |
1622 | } |
1623 | } | |
fc243e94 | 1624 | if (!p) |
17c76198 | 1625 | { |
fc243e94 | 1626 | p = exim_default_gnutls_priority; |
83e2f8a2 | 1627 | DEBUG(D_tls) |
fc243e94 | 1628 | debug_printf("GnuTLS using default session cipher/priority \"%s\"\n", p); |
17c76198 | 1629 | } |
83da1223 | 1630 | |
452a164f JH |
1631 | if ((rc = gnutls_priority_init(&state->priority_cache, CCS p, &errpos))) |
1632 | return tls_error_gnu(string_sprintf( | |
1633 | "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"", | |
1634 | p, errpos - CS p, errpos), | |
1635 | rc, host, errstr); | |
17c76198 | 1636 | |
452a164f JH |
1637 | if ((rc = gnutls_priority_set(state->session, state->priority_cache))) |
1638 | return tls_error_gnu(US"gnutls_priority_set", rc, host, errstr); | |
17c76198 | 1639 | |
b10c87b3 JH |
1640 | /* This also sets the server ticket expiration time to the same, and |
1641 | the STEK rotation time to 3x. */ | |
1642 | ||
17c76198 PP |
1643 | gnutls_db_set_cache_expiration(state->session, ssl_session_timeout); |
1644 | ||
1645 | /* Reduce security in favour of increased compatibility, if the admin | |
1646 | decides to make that trade-off. */ | |
1647 | if (gnutls_compat_mode) | |
83da1223 | 1648 | { |
17c76198 PP |
1649 | #if LIBGNUTLS_VERSION_NUMBER >= 0x020104 |
1650 | DEBUG(D_tls) debug_printf("lowering GnuTLS security, compatibility mode\n"); | |
1651 | gnutls_session_enable_compatibility_mode(state->session); | |
1652 | #else | |
1653 | DEBUG(D_tls) debug_printf("Unable to set gnutls_compat_mode - GnuTLS version too old\n"); | |
1654 | #endif | |
83da1223 PH |
1655 | } |
1656 | ||
17c76198 | 1657 | *caller_state = state; |
17c76198 | 1658 | return OK; |
83da1223 PH |
1659 | } |
1660 | ||
1661 | ||
1662 | ||
059ec3d9 | 1663 | /************************************************* |
17c76198 | 1664 | * Extract peer information * |
059ec3d9 PH |
1665 | *************************************************/ |
1666 | ||
f1be21cf JH |
1667 | static const uschar * |
1668 | cipher_stdname_kcm(gnutls_kx_algorithm_t kx, gnutls_cipher_algorithm_t cipher, | |
1669 | gnutls_mac_algorithm_t mac) | |
1670 | { | |
1671 | uschar cs_id[2]; | |
1672 | gnutls_kx_algorithm_t kx_i; | |
1673 | gnutls_cipher_algorithm_t cipher_i; | |
1674 | gnutls_mac_algorithm_t mac_i; | |
1675 | ||
1676 | for (size_t i = 0; | |
1677 | gnutls_cipher_suite_info(i, cs_id, &kx_i, &cipher_i, &mac_i, NULL); | |
1678 | i++) | |
1679 | if (kx_i == kx && cipher_i == cipher && mac_i == mac) | |
1680 | return cipher_stdname(cs_id[0], cs_id[1]); | |
1681 | return NULL; | |
1682 | } | |
1683 | ||
1684 | ||
1685 | ||
17c76198 | 1686 | /* Called from both server and client code. |
4fe99a6c PP |
1687 | Only this is allowed to set state->peerdn and state->have_set_peerdn |
1688 | and we use that to detect double-calls. | |
059ec3d9 | 1689 | |
75fe387d PP |
1690 | NOTE: the state blocks last while the TLS connection is up, which is fine |
1691 | for logging in the server side, but for the client side, we log after teardown | |
1692 | in src/deliver.c. While the session is up, we can twist about states and | |
1693 | repoint tls_* globals, but those variables used for logging or other variable | |
1694 | expansion that happens _after_ delivery need to have a longer life-time. | |
1695 | ||
1696 | So for those, we get the data from POOL_PERM; the re-invoke guard keeps us from | |
1697 | doing this more than once per generation of a state context. We set them in | |
1698 | the state context, and repoint tls_* to them. After the state goes away, the | |
1699 | tls_* copies of the pointers remain valid and client delivery logging is happy. | |
1700 | ||
1701 | tls_certificate_verified is a BOOL, so the tls_peerdn and tls_cipher issues | |
1702 | don't apply. | |
1703 | ||
059ec3d9 | 1704 | Arguments: |
17c76198 | 1705 | state exim_gnutls_state_st * |
cf0c6164 | 1706 | errstr pointer to error string |
059ec3d9 | 1707 | |
17c76198 | 1708 | Returns: OK/DEFER/FAIL |
059ec3d9 PH |
1709 | */ |
1710 | ||
17c76198 | 1711 | static int |
b10c87b3 | 1712 | peer_status(exim_gnutls_state_st * state, uschar ** errstr) |
059ec3d9 | 1713 | { |
b10c87b3 JH |
1714 | gnutls_session_t session = state->session; |
1715 | const gnutls_datum_t * cert_list; | |
75fe387d | 1716 | int old_pool, rc; |
17c76198 | 1717 | unsigned int cert_list_size = 0; |
4fe99a6c PP |
1718 | gnutls_protocol_t protocol; |
1719 | gnutls_cipher_algorithm_t cipher; | |
1720 | gnutls_kx_algorithm_t kx; | |
1721 | gnutls_mac_algorithm_t mac; | |
17c76198 PP |
1722 | gnutls_certificate_type_t ct; |
1723 | gnutls_x509_crt_t crt; | |
b10c87b3 | 1724 | uschar * dn_buf; |
17c76198 | 1725 | size_t sz; |
059ec3d9 | 1726 | |
4fe99a6c | 1727 | if (state->have_set_peerdn) |
17c76198 | 1728 | return OK; |
4fe99a6c | 1729 | state->have_set_peerdn = TRUE; |
059ec3d9 | 1730 | |
4fe99a6c | 1731 | state->peerdn = NULL; |
059ec3d9 | 1732 | |
4fe99a6c | 1733 | /* tls_cipher */ |
b10c87b3 JH |
1734 | cipher = gnutls_cipher_get(session); |
1735 | protocol = gnutls_protocol_get_version(session); | |
1736 | mac = gnutls_mac_get(session); | |
b9c6f63c JH |
1737 | kx = |
1738 | #ifdef GNUTLS_TLS1_3 | |
1739 | protocol >= GNUTLS_TLS1_3 ? 0 : | |
1740 | #endif | |
b10c87b3 | 1741 | gnutls_kx_get(session); |
4fe99a6c | 1742 | |
75fe387d | 1743 | old_pool = store_pool; |
f1be21cf | 1744 | { |
b10c87b3 | 1745 | tls_support * tlsp = state->tlsp; |
f1be21cf | 1746 | store_pool = POOL_PERM; |
d9acfc1c JH |
1747 | |
1748 | #ifdef SUPPORT_GNUTLS_SESS_DESC | |
1749 | { | |
1750 | gstring * g = NULL; | |
b10c87b3 | 1751 | uschar * s = US gnutls_session_get_desc(session), c; |
d9acfc1c JH |
1752 | |
1753 | /* Nikos M suggests we use this by preference. It returns like: | |
1754 | (TLS1.3)-(ECDHE-SECP256R1)-(RSA-PSS-RSAE-SHA256)-(AES-256-GCM) | |
1755 | ||
1756 | For partial back-compat, put a colon after the TLS version, replace the | |
1757 | )-( grouping with __, replace in-group - with _ and append the :keysize. */ | |
1758 | ||
1759 | /* debug_printf("peer_status: gnutls_session_get_desc %s\n", s); */ | |
1760 | ||
1761 | for (s++; (c = *s) && c != ')'; s++) g = string_catn(g, s, 1); | |
e4307860 | 1762 | |
5b195d6b | 1763 | tlsp->ver = string_copyn(g->s, g->ptr); |
e4307860 JH |
1764 | for (uschar * p = US tlsp->ver; *p; p++) |
1765 | if (*p == '-') { *p = '\0'; break; } /* TLS1.0-PKIX -> TLS1.0 */ | |
1766 | ||
d9acfc1c JH |
1767 | g = string_catn(g, US":", 1); |
1768 | if (*s) s++; /* now on _ between groups */ | |
1769 | while ((c = *s)) | |
1770 | { | |
e4307860 JH |
1771 | for (*++s && ++s; (c = *s) && c != ')'; s++) |
1772 | g = string_catn(g, c == '-' ? US"_" : s, 1); | |
d9acfc1c JH |
1773 | /* now on ) closing group */ |
1774 | if ((c = *s) && *++s == '-') g = string_catn(g, US"__", 2); | |
1775 | /* now on _ between groups */ | |
1776 | } | |
1777 | g = string_catn(g, US":", 1); | |
1778 | g = string_cat(g, string_sprintf("%d", (int) gnutls_cipher_get_key_size(cipher) * 8)); | |
1779 | state->ciphersuite = string_from_gstring(g); | |
1780 | } | |
1781 | #else | |
f1be21cf JH |
1782 | state->ciphersuite = string_sprintf("%s:%s:%d", |
1783 | gnutls_protocol_get_name(protocol), | |
1784 | gnutls_cipher_suite_get_name(kx, cipher, mac), | |
1785 | (int) gnutls_cipher_get_key_size(cipher) * 8); | |
1786 | ||
1787 | /* I don't see a way that spaces could occur, in the current GnuTLS | |
1788 | code base, but it was a concern in the old code and perhaps older GnuTLS | |
1789 | releases did return "TLS 1.0"; play it safe, just in case. */ | |
1790 | ||
1791 | for (uschar * p = state->ciphersuite; *p; p++) if (isspace(*p)) *p = '-'; | |
5b195d6b JH |
1792 | tlsp->ver = string_copyn(state->ciphersuite, |
1793 | Ustrchr(state->ciphersuite, ':') - state->ciphersuite); | |
d9acfc1c JH |
1794 | #endif |
1795 | ||
1796 | /* debug_printf("peer_status: ciphersuite %s\n", state->ciphersuite); */ | |
1797 | ||
b10c87b3 JH |
1798 | tlsp->cipher = state->ciphersuite; |
1799 | tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; | |
f1be21cf | 1800 | |
b10c87b3 | 1801 | tlsp->cipher_stdname = cipher_stdname_kcm(kx, cipher, mac); |
f1be21cf | 1802 | } |
75fe387d | 1803 | store_pool = old_pool; |
4fe99a6c PP |
1804 | |
1805 | /* tls_peerdn */ | |
b10c87b3 | 1806 | cert_list = gnutls_certificate_get_peers(session, &cert_list_size); |
83da1223 | 1807 | |
f1be21cf | 1808 | if (!cert_list || cert_list_size == 0) |
17c76198 | 1809 | { |
17c76198 PP |
1810 | DEBUG(D_tls) debug_printf("TLS: no certificate from peer (%p & %d)\n", |
1811 | cert_list, cert_list_size); | |
e51c7be2 | 1812 | if (state->verify_requirement >= VERIFY_REQUIRED) |
17c76198 | 1813 | return tls_error(US"certificate verification failed", |
48224640 | 1814 | US"no certificate received from peer", state->host, errstr); |
17c76198 PP |
1815 | return OK; |
1816 | } | |
059ec3d9 | 1817 | |
b10c87b3 | 1818 | if ((ct = gnutls_certificate_type_get(session)) != GNUTLS_CRT_X509) |
059ec3d9 | 1819 | { |
95f52235 | 1820 | const uschar * ctn = US gnutls_certificate_type_get_name(ct); |
17c76198 PP |
1821 | DEBUG(D_tls) |
1822 | debug_printf("TLS: peer cert not X.509 but instead \"%s\"\n", ctn); | |
e51c7be2 | 1823 | if (state->verify_requirement >= VERIFY_REQUIRED) |
17c76198 | 1824 | return tls_error(US"certificate verification not possible, unhandled type", |
cf0c6164 | 1825 | ctn, state->host, errstr); |
17c76198 | 1826 | return OK; |
83da1223 | 1827 | } |
059ec3d9 | 1828 | |
e51c7be2 JH |
1829 | #define exim_gnutls_peer_err(Label) \ |
1830 | do { \ | |
1831 | if (rc != GNUTLS_E_SUCCESS) \ | |
1832 | { \ | |
1833 | DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", \ | |
1834 | (Label), gnutls_strerror(rc)); \ | |
1835 | if (state->verify_requirement >= VERIFY_REQUIRED) \ | |
452a164f | 1836 | return tls_error_gnu((Label), rc, state->host, errstr); \ |
e51c7be2 JH |
1837 | return OK; \ |
1838 | } \ | |
1839 | } while (0) | |
17c76198 | 1840 | |
9d1c15ef JH |
1841 | rc = import_cert(&cert_list[0], &crt); |
1842 | exim_gnutls_peer_err(US"cert 0"); | |
1843 | ||
1844 | state->tlsp->peercert = state->peercert = crt; | |
17c76198 | 1845 | |
17c76198 PP |
1846 | sz = 0; |
1847 | rc = gnutls_x509_crt_get_dn(crt, NULL, &sz); | |
1848 | if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) | |
83da1223 | 1849 | { |
17c76198 PP |
1850 | exim_gnutls_peer_err(US"getting size for cert DN failed"); |
1851 | return FAIL; /* should not happen */ | |
059ec3d9 | 1852 | } |
f3ebb786 | 1853 | dn_buf = store_get_perm(sz, TRUE); /* tainted */ |
17c76198 PP |
1854 | rc = gnutls_x509_crt_get_dn(crt, CS dn_buf, &sz); |
1855 | exim_gnutls_peer_err(US"failed to extract certificate DN [gnutls_x509_crt_get_dn(cert 0)]"); | |
9d1c15ef | 1856 | |
17c76198 PP |
1857 | state->peerdn = dn_buf; |
1858 | ||
1859 | return OK; | |
1860 | #undef exim_gnutls_peer_err | |
1861 | } | |
059ec3d9 | 1862 | |
059ec3d9 | 1863 | |
059ec3d9 | 1864 | |
059ec3d9 | 1865 | |
17c76198 PP |
1866 | /************************************************* |
1867 | * Verify peer certificate * | |
1868 | *************************************************/ | |
059ec3d9 | 1869 | |
17c76198 PP |
1870 | /* Called from both server and client code. |
1871 | *Should* be using a callback registered with | |
1872 | gnutls_certificate_set_verify_function() to fail the handshake if we dislike | |
1873 | the peer information, but that's too new for some OSes. | |
059ec3d9 | 1874 | |
17c76198 | 1875 | Arguments: |
899b8bbc JH |
1876 | state exim_gnutls_state_st * |
1877 | errstr where to put an error message | |
059ec3d9 | 1878 | |
17c76198 PP |
1879 | Returns: |
1880 | FALSE if the session should be rejected | |
1881 | TRUE if the cert is okay or we just don't care | |
1882 | */ | |
059ec3d9 | 1883 | |
17c76198 | 1884 | static BOOL |
28646fa9 | 1885 | verify_certificate(exim_gnutls_state_st * state, uschar ** errstr) |
17c76198 PP |
1886 | { |
1887 | int rc; | |
899b8bbc JH |
1888 | uint verify; |
1889 | ||
8008accd | 1890 | DEBUG(D_tls) debug_printf("TLS: checking peer certificate\n"); |
cf0c6164 | 1891 | *errstr = NULL; |
b10c87b3 | 1892 | rc = peer_status(state, errstr); |
17c76198 | 1893 | |
b10c87b3 JH |
1894 | if (state->verify_requirement == VERIFY_NONE) |
1895 | return TRUE; | |
1896 | ||
1897 | if (rc != OK || !state->peerdn) | |
e6060e2c | 1898 | { |
17c76198 | 1899 | verify = GNUTLS_CERT_INVALID; |
cf0c6164 | 1900 | *errstr = US"certificate not supplied"; |
17c76198 PP |
1901 | } |
1902 | else | |
899b8bbc JH |
1903 | |
1904 | { | |
1905 | #ifdef SUPPORT_DANE | |
1906 | if (state->verify_requirement == VERIFY_DANE && state->host) | |
1907 | { | |
1908 | /* Using dane_verify_session_crt() would be easy, as it does it all for us | |
1909 | including talking to a DNS resolver. But we want to do that bit ourselves | |
1910 | as the testsuite intercepts and fakes its own DNS environment. */ | |
1911 | ||
1912 | dane_state_t s; | |
1913 | dane_query_t r; | |
899b8bbc | 1914 | uint lsize; |
94c13285 JH |
1915 | const gnutls_datum_t * certlist = |
1916 | gnutls_certificate_get_peers(state->session, &lsize); | |
1917 | int usage = tls_out.tlsa_usage; | |
1918 | ||
1919 | # ifdef GNUTLS_BROKEN_DANE_VALIDATION | |
1920 | /* Split the TLSA records into two sets, TA and EE selectors. Run the | |
1921 | dane-verification separately so that we know which selector verified; | |
570cb1bd | 1922 | then we know whether to do name-verification (needed for TA but not EE). */ |
94c13285 JH |
1923 | |
1924 | if (usage == ((1<<DANESSL_USAGE_DANE_TA) | (1<<DANESSL_USAGE_DANE_EE))) | |
bd5b3f3c | 1925 | { /* a mixed-usage bundle */ |
94c13285 JH |
1926 | int i, j, nrec; |
1927 | const char ** dd; | |
1928 | int * ddl; | |
1929 | ||
1930 | for(nrec = 0; state->dane_data_len[nrec]; ) nrec++; | |
1931 | nrec++; | |
1932 | ||
f3ebb786 JH |
1933 | dd = store_get(nrec * sizeof(uschar *), FALSE); |
1934 | ddl = store_get(nrec * sizeof(int), FALSE); | |
94c13285 JH |
1935 | nrec--; |
1936 | ||
1937 | if ((rc = dane_state_init(&s, 0))) | |
1938 | goto tlsa_prob; | |
1939 | ||
1940 | for (usage = DANESSL_USAGE_DANE_EE; | |
1941 | usage >= DANESSL_USAGE_DANE_TA; usage--) | |
1942 | { /* take records with this usage */ | |
1943 | for (j = i = 0; i < nrec; i++) | |
1944 | if (state->dane_data[i][0] == usage) | |
1945 | { | |
1946 | dd[j] = state->dane_data[i]; | |
1947 | ddl[j++] = state->dane_data_len[i]; | |
1948 | } | |
1949 | if (j) | |
1950 | { | |
1951 | dd[j] = NULL; | |
1952 | ddl[j] = 0; | |
1953 | ||
1954 | if ((rc = dane_raw_tlsa(s, &r, (char * const *)dd, ddl, 1, 0))) | |
1955 | goto tlsa_prob; | |
1956 | ||
1957 | if ((rc = dane_verify_crt_raw(s, certlist, lsize, | |
1958 | gnutls_certificate_type_get(state->session), | |
1959 | r, 0, | |
1960 | usage == DANESSL_USAGE_DANE_EE | |
1961 | ? DANE_VFLAG_ONLY_CHECK_EE_USAGE : 0, | |
1962 | &verify))) | |
1963 | { | |
1964 | DEBUG(D_tls) | |
1965 | debug_printf("TLSA record problem: %s\n", dane_strerror(rc)); | |
1966 | } | |
1967 | else if (verify == 0) /* verification passed */ | |
1968 | { | |
1969 | usage = 1 << usage; | |
1970 | break; | |
1971 | } | |
1972 | } | |
1973 | } | |
899b8bbc | 1974 | |
94c13285 JH |
1975 | if (rc) goto tlsa_prob; |
1976 | } | |
1977 | else | |
1978 | # endif | |
899b8bbc | 1979 | { |
94c13285 JH |
1980 | if ( (rc = dane_state_init(&s, 0)) |
1981 | || (rc = dane_raw_tlsa(s, &r, state->dane_data, state->dane_data_len, | |
1982 | 1, 0)) | |
1983 | || (rc = dane_verify_crt_raw(s, certlist, lsize, | |
1984 | gnutls_certificate_type_get(state->session), | |
5ec37a55 | 1985 | r, 0, |
94c13285 JH |
1986 | # ifdef GNUTLS_BROKEN_DANE_VALIDATION |
1987 | usage == (1 << DANESSL_USAGE_DANE_EE) | |
1988 | ? DANE_VFLAG_ONLY_CHECK_EE_USAGE : 0, | |
1989 | # else | |
1990 | 0, | |
1991 | # endif | |
1992 | &verify)) | |
1993 | ) | |
1994 | goto tlsa_prob; | |
899b8bbc | 1995 | } |
94c13285 JH |
1996 | |
1997 | if (verify != 0) /* verification failed */ | |
899b8bbc JH |
1998 | { |
1999 | gnutls_datum_t str; | |
2000 | (void) dane_verification_status_print(verify, &str, 0); | |
2001 | *errstr = US str.data; /* don't bother to free */ | |
2002 | goto badcert; | |
2003 | } | |
28646fa9 | 2004 | |
94c13285 JH |
2005 | # ifdef GNUTLS_BROKEN_DANE_VALIDATION |
2006 | /* If a TA-mode TLSA record was used for verification we must additionally | |
570cb1bd | 2007 | verify the cert name (but not the CA chain). For EE-mode, skip it. */ |
28646fa9 | 2008 | |
94c13285 JH |
2009 | if (usage & (1 << DANESSL_USAGE_DANE_EE)) |
2010 | # endif | |
28646fa9 | 2011 | { |
570cb1bd | 2012 | state->peer_dane_verified = state->peer_cert_verified = TRUE; |
28646fa9 JH |
2013 | goto goodcert; |
2014 | } | |
570cb1bd JH |
2015 | # ifdef GNUTLS_BROKEN_DANE_VALIDATION |
2016 | /* Assume that the name on the A-record is the one that should be matching | |
2017 | the cert. An alternate view is that the domain part of the email address | |
2018 | is also permissible. */ | |
2019 | ||
2020 | if (gnutls_x509_crt_check_hostname(state->tlsp->peercert, | |
2021 | CS state->host->name)) | |
2022 | { | |
2023 | state->peer_dane_verified = state->peer_cert_verified = TRUE; | |
2024 | goto goodcert; | |
2025 | } | |
2026 | # endif | |
899b8bbc | 2027 | } |
570cb1bd | 2028 | #endif /*SUPPORT_DANE*/ |
899b8bbc | 2029 | |
17c76198 | 2030 | rc = gnutls_certificate_verify_peers2(state->session, &verify); |
899b8bbc | 2031 | } |
e6060e2c | 2032 | |
899b8bbc | 2033 | /* Handle the result of verification. INVALID is set if any others are. */ |
059ec3d9 | 2034 | |
28646fa9 | 2035 | if (rc < 0 || verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED)) |
17c76198 PP |
2036 | { |
2037 | state->peer_cert_verified = FALSE; | |
cf0c6164 | 2038 | if (!*errstr) |
184384c3 JH |
2039 | { |
2040 | #ifdef GNUTLS_CERT_VFY_STATUS_PRINT | |
2041 | DEBUG(D_tls) | |
2042 | { | |
2043 | gnutls_datum_t txt; | |
2044 | ||
2045 | if (gnutls_certificate_verification_status_print(verify, | |
2046 | gnutls_certificate_type_get(state->session), &txt, 0) | |
2047 | == GNUTLS_E_SUCCESS) | |
2048 | { | |
2049 | debug_printf("%s\n", txt.data); | |
2050 | gnutls_free(txt.data); | |
2051 | } | |
2052 | } | |
2053 | #endif | |
cf0c6164 JH |
2054 | *errstr = verify & GNUTLS_CERT_REVOKED |
2055 | ? US"certificate revoked" : US"certificate invalid"; | |
184384c3 | 2056 | } |
059ec3d9 | 2057 | |
17c76198 | 2058 | DEBUG(D_tls) |
e51c7be2 | 2059 | debug_printf("TLS certificate verification failed (%s): peerdn=\"%s\"\n", |
cf0c6164 | 2060 | *errstr, state->peerdn ? state->peerdn : US"<unset>"); |
059ec3d9 | 2061 | |
e51c7be2 | 2062 | if (state->verify_requirement >= VERIFY_REQUIRED) |
899b8bbc | 2063 | goto badcert; |
17c76198 | 2064 | DEBUG(D_tls) |
4789da3a | 2065 | debug_printf("TLS verify failure overridden (host in tls_try_verify_hosts)\n"); |
17c76198 | 2066 | } |
e51c7be2 | 2067 | |
17c76198 PP |
2068 | else |
2069 | { | |
5fd28bb8 JH |
2070 | /* Client side, check the server's certificate name versus the name on the |
2071 | A-record for the connection we made. What to do for server side - what name | |
2072 | to use for client? We document that there is no such checking for server | |
2073 | side. */ | |
2074 | ||
2075 | if ( state->exp_tls_verify_cert_hostnames | |
2076 | && !gnutls_x509_crt_check_hostname(state->tlsp->peercert, | |
2077 | CS state->exp_tls_verify_cert_hostnames) | |
2078 | ) | |
e51c7be2 | 2079 | { |
5fd28bb8 JH |
2080 | DEBUG(D_tls) |
2081 | debug_printf("TLS certificate verification failed: cert name mismatch\n"); | |
2082 | if (state->verify_requirement >= VERIFY_REQUIRED) | |
2083 | goto badcert; | |
2084 | return TRUE; | |
e51c7be2 | 2085 | } |
5fd28bb8 | 2086 | |
17c76198 | 2087 | state->peer_cert_verified = TRUE; |
e51c7be2 | 2088 | DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=\"%s\"\n", |
4fe99a6c | 2089 | state->peerdn ? state->peerdn : US"<unset>"); |
17c76198 | 2090 | } |
059ec3d9 | 2091 | |
28646fa9 JH |
2092 | goodcert: |
2093 | state->tlsp->peerdn = state->peerdn; | |
2094 | return TRUE; | |
899b8bbc | 2095 | |
b83314e3 | 2096 | #ifdef SUPPORT_DANE |
94c13285 | 2097 | tlsa_prob: |
624f33df JH |
2098 | *errstr = string_sprintf("TLSA record problem: %s", |
2099 | rc == DANE_E_REQUESTED_DATA_NOT_AVAILABLE ? "none usable" : dane_strerror(rc)); | |
b83314e3 JH |
2100 | #endif |
2101 | ||
899b8bbc JH |
2102 | badcert: |
2103 | gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); | |
2104 | return FALSE; | |
17c76198 | 2105 | } |
059ec3d9 | 2106 | |
17c76198 PP |
2107 | |
2108 | ||
2109 | ||
2110 | /* ------------------------------------------------------------------------ */ | |
2111 | /* Callbacks */ | |
2112 | ||
2113 | /* Logging function which can be registered with | |
2114 | * gnutls_global_set_log_function() | |
2115 | * gnutls_global_set_log_level() 0..9 | |
2116 | */ | |
af3498d6 | 2117 | #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 |
059ec3d9 | 2118 | static void |
17c76198 | 2119 | exim_gnutls_logger_cb(int level, const char *message) |
059ec3d9 | 2120 | { |
8c79eebf PP |
2121 | size_t len = strlen(message); |
2122 | if (len < 1) | |
2123 | { | |
2124 | DEBUG(D_tls) debug_printf("GnuTLS<%d> empty debug message\n", level); | |
2125 | return; | |
2126 | } | |
2127 | DEBUG(D_tls) debug_printf("GnuTLS<%d>: %s%s", level, message, | |
2128 | message[len-1] == '\n' ? "" : "\n"); | |
17c76198 | 2129 | } |
af3498d6 | 2130 | #endif |
059ec3d9 | 2131 | |
059ec3d9 | 2132 | |
17c76198 PP |
2133 | /* Called after client hello, should handle SNI work. |
2134 | This will always set tls_sni (state->received_sni) if available, | |
2135 | and may trigger presenting different certificates, | |
2136 | if state->trigger_sni_changes is TRUE. | |
059ec3d9 | 2137 | |
17c76198 PP |
2138 | Should be registered with |
2139 | gnutls_handshake_set_post_client_hello_function() | |
059ec3d9 | 2140 | |
17c76198 PP |
2141 | "This callback must return 0 on success or a gnutls error code to terminate the |
2142 | handshake.". | |
059ec3d9 | 2143 | |
17c76198 PP |
2144 | For inability to get SNI information, we return 0. |
2145 | We only return non-zero if re-setup failed. | |
817d9f57 | 2146 | Only used for server-side TLS. |
17c76198 | 2147 | */ |
44bbabb5 | 2148 | |
17c76198 PP |
2149 | static int |
2150 | exim_sni_handling_cb(gnutls_session_t session) | |
2151 | { | |
2152 | char sni_name[MAX_HOST_LEN]; | |
2153 | size_t data_len = MAX_HOST_LEN; | |
817d9f57 | 2154 | exim_gnutls_state_st *state = &state_server; |
17c76198 PP |
2155 | unsigned int sni_type; |
2156 | int rc, old_pool; | |
cf0c6164 | 2157 | uschar * dummy_errstr; |
17c76198 PP |
2158 | |
2159 | rc = gnutls_server_name_get(session, sni_name, &data_len, &sni_type, 0); | |
b34fc30c PP |
2160 | if (rc != GNUTLS_E_SUCCESS) |
2161 | { | |
8775d84f | 2162 | DEBUG(D_tls) |
b34fc30c PP |
2163 | if (rc == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) |
2164 | debug_printf("TLS: no SNI presented in handshake.\n"); | |
2165 | else | |
2166 | debug_printf("TLS failure: gnutls_server_name_get(): %s [%d]\n", | |
2167 | gnutls_strerror(rc), rc); | |
b34fc30c PP |
2168 | return 0; |
2169 | } | |
2170 | ||
17c76198 PP |
2171 | if (sni_type != GNUTLS_NAME_DNS) |
2172 | { | |
2173 | DEBUG(D_tls) debug_printf("TLS: ignoring SNI of unhandled type %u\n", sni_type); | |
2174 | return 0; | |
2175 | } | |
44bbabb5 | 2176 | |
17c76198 PP |
2177 | /* We now have a UTF-8 string in sni_name */ |
2178 | old_pool = store_pool; | |
2179 | store_pool = POOL_PERM; | |
89a80675 | 2180 | state->received_sni = string_copy_taint(US sni_name, TRUE); |
17c76198 PP |
2181 | store_pool = old_pool; |
2182 | ||
2183 | /* We set this one now so that variable expansions below will work */ | |
817d9f57 | 2184 | state->tlsp->sni = state->received_sni; |
17c76198 PP |
2185 | |
2186 | DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", sni_name, | |
2187 | state->trigger_sni_changes ? "" : " (unused for certificate selection)"); | |
2188 | ||
2189 | if (!state->trigger_sni_changes) | |
2190 | return 0; | |
2191 | ||
cf0c6164 | 2192 | if ((rc = tls_expand_session_files(state, &dummy_errstr)) != OK) |
17c76198 PP |
2193 | { |
2194 | /* If the setup of certs/etc failed before handshake, TLS would not have | |
2195 | been offered. The best we can do now is abort. */ | |
2196 | return GNUTLS_E_APPLICATION_ERROR_MIN; | |
2197 | } | |
2198 | ||
cf0c6164 | 2199 | rc = tls_set_remaining_x509(state, &dummy_errstr); |
1365611d PP |
2200 | if (rc != OK) return GNUTLS_E_APPLICATION_ERROR_MIN; |
2201 | ||
2202 | return 0; | |
059ec3d9 PH |
2203 | } |
2204 | ||
2205 | ||
2206 | ||
0cbf2b82 | 2207 | #ifndef DISABLE_EVENT |
a7538db1 JH |
2208 | /* |
2209 | We use this callback to get observability and detail-level control | |
723fe533 JH |
2210 | for an exim TLS connection (either direction), raising a tls:cert event |
2211 | for each cert in the chain presented by the peer. Any event | |
a7538db1 JH |
2212 | can deny verification. |
2213 | ||
2214 | Return 0 for the handshake to continue or non-zero to terminate. | |
2215 | */ | |
2216 | ||
2217 | static int | |
723fe533 | 2218 | verify_cb(gnutls_session_t session) |
a7538db1 | 2219 | { |
27f19eb4 | 2220 | const gnutls_datum_t * cert_list; |
a7538db1 JH |
2221 | unsigned int cert_list_size = 0; |
2222 | gnutls_x509_crt_t crt; | |
2223 | int rc; | |
b30275b8 | 2224 | uschar * yield; |
a7538db1 JH |
2225 | exim_gnutls_state_st * state = gnutls_session_get_ptr(session); |
2226 | ||
bd5b3f3c | 2227 | if ((cert_list = gnutls_certificate_get_peers(session, &cert_list_size))) |
a7538db1 JH |
2228 | while (cert_list_size--) |
2229 | { | |
bd5b3f3c | 2230 | if ((rc = import_cert(&cert_list[cert_list_size], &crt)) != GNUTLS_E_SUCCESS) |
a7538db1 JH |
2231 | { |
2232 | DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n", | |
2233 | cert_list_size, gnutls_strerror(rc)); | |
2234 | break; | |
2235 | } | |
2236 | ||
2237 | state->tlsp->peercert = crt; | |
b30275b8 JH |
2238 | if ((yield = event_raise(state->event_action, |
2239 | US"tls:cert", string_sprintf("%d", cert_list_size)))) | |
a7538db1 JH |
2240 | { |
2241 | log_write(0, LOG_MAIN, | |
b30275b8 JH |
2242 | "SSL verify denied by event-action: depth=%d: %s", |
2243 | cert_list_size, yield); | |
a7538db1 JH |
2244 | return 1; /* reject */ |
2245 | } | |
2246 | state->tlsp->peercert = NULL; | |
2247 | } | |
2248 | ||
2249 | return 0; | |
2250 | } | |
2251 | ||
2252 | #endif | |
44662487 JH |
2253 | |
2254 | ||
f20cfa4a JH |
2255 | static gstring * |
2256 | ddump(gnutls_datum_t * d) | |
2257 | { | |
2258 | gstring * g = string_get((d->size+1) * 2); | |
2259 | uschar * s = d->data; | |
2260 | for (unsigned i = d->size; i > 0; i--, s++) | |
2261 | { | |
2262 | g = string_catn(g, US "0123456789abcdef" + (*s >> 4), 1); | |
2263 | g = string_catn(g, US "0123456789abcdef" + (*s & 0xf), 1); | |
2264 | } | |
2265 | return g; | |
2266 | } | |
17c76198 | 2267 | |
dc6d1769 JH |
2268 | static void |
2269 | post_handshake_debug(exim_gnutls_state_st * state) | |
2270 | { | |
dc6d1769 JH |
2271 | #ifdef SUPPORT_GNUTLS_SESS_DESC |
2272 | debug_printf("%s\n", gnutls_session_get_desc(state->session)); | |
2273 | #endif | |
2274 | #ifdef SUPPORT_GNUTLS_KEYLOG | |
e326959e JH |
2275 | |
2276 | # ifdef EXIM_HAVE_TLS1_3 | |
dc6d1769 | 2277 | if (gnutls_protocol_get_version(state->session) < GNUTLS_TLS1_3) |
a8af957d JH |
2278 | #else |
2279 | if (TRUE) | |
2280 | #endif | |
dc6d1769 JH |
2281 | { |
2282 | gnutls_datum_t c, s; | |
2283 | gstring * gc, * gs; | |
2284 | /* we only want the client random and the master secret */ | |
2285 | gnutls_session_get_random(state->session, &c, &s); | |
2286 | gnutls_session_get_master_secret(state->session, &s); | |
2287 | gc = ddump(&c); | |
2288 | gs = ddump(&s); | |
2289 | debug_printf("CLIENT_RANDOM %.*s %.*s\n", (int)gc->ptr, gc->s, (int)gs->ptr, gs->s); | |
2290 | } | |
2291 | else | |
2292 | debug_printf("To get keying info for TLS1.3 is hard:\n" | |
2293 | " set environment variable SSLKEYLOGFILE to a filename writable by uid exim\n" | |
2294 | " add SSLKEYLOGFILE to keep_environment in the exim config\n" | |
2295 | " run exim as root\n" | |
e326959e JH |
2296 | " if using sudo, add SSLKEYLOGFILE to env_keep in /etc/sudoers\n" |
2297 | " (works for TLS1.2 also, and saves cut-paste into file)\n"); | |
dc6d1769 JH |
2298 | #endif |
2299 | } | |
2300 | ||
b10c87b3 JH |
2301 | |
2302 | #ifdef EXPERIMENTAL_TLS_RESUME | |
2303 | static int | |
2304 | tls_server_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when, | |
2305 | unsigned incoming, const gnutls_datum_t * msg) | |
2306 | { | |
2307 | DEBUG(D_tls) debug_printf("newticket cb\n"); | |
2308 | tls_in.resumption |= RESUME_CLIENT_REQUESTED; | |
2309 | return 0; | |
2310 | } | |
2311 | ||
2312 | static void | |
2313 | tls_server_resume_prehandshake(exim_gnutls_state_st * state) | |
2314 | { | |
2315 | /* Should the server offer session resumption? */ | |
2316 | tls_in.resumption = RESUME_SUPPORTED; | |
2317 | if (verify_check_host(&tls_resumption_hosts) == OK) | |
2318 | { | |
2319 | int rc; | |
2320 | /* GnuTLS appears to not do ticket overlap, but does emit a fresh ticket when | |
2321 | an offered resumption is unacceptable. We lose one resumption per ticket | |
2322 | lifetime, and sessions cannot be indefinitely re-used. There seems to be no | |
2323 | way (3.6.7) of changing the default number of 2 TLS1.3 tickets issued, but at | |
2324 | least they go out in a single packet. */ | |
2325 | ||
2326 | if (!(rc = gnutls_session_ticket_enable_server(state->session, | |
2327 | &server_sessticket_key))) | |
2328 | tls_in.resumption |= RESUME_SERVER_TICKET; | |
2329 | else | |
2330 | DEBUG(D_tls) | |
2331 | debug_printf("enabling session tickets: %s\n", US gnutls_strerror(rc)); | |
2332 | ||
2333 | /* Try to tell if we see a ticket request */ | |
2334 | gnutls_handshake_set_hook_function(state->session, | |
e5489333 | 2335 | GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb); |
b10c87b3 JH |
2336 | } |
2337 | } | |
2338 | ||
2339 | static void | |
2340 | tls_server_resume_posthandshake(exim_gnutls_state_st * state) | |
2341 | { | |
2342 | if (gnutls_session_resumption_requested(state->session)) | |
2343 | { | |
2344 | /* This tells us the client sent a full ticket. We use a | |
2345 | callback on session-ticket request, elsewhere, to tell | |
2346 | if a client asked for a ticket. */ | |
2347 | ||
2348 | tls_in.resumption |= RESUME_CLIENT_SUGGESTED; | |
2349 | DEBUG(D_tls) debug_printf("client requested resumption\n"); | |
2350 | } | |
2351 | if (gnutls_session_is_resumed(state->session)) | |
2352 | { | |
2353 | tls_in.resumption |= RESUME_USED; | |
2354 | DEBUG(D_tls) debug_printf("Session resumed\n"); | |
2355 | } | |
2356 | } | |
2357 | #endif | |
17c76198 PP |
2358 | /* ------------------------------------------------------------------------ */ |
2359 | /* Exported functions */ | |
2360 | ||
2361 | ||
2362 | ||
2363 | ||
059ec3d9 PH |
2364 | /************************************************* |
2365 | * Start a TLS session in a server * | |
2366 | *************************************************/ | |
2367 | ||
2368 | /* This is called when Exim is running as a server, after having received | |
2369 | the STARTTLS command. It must respond to that command, and then negotiate | |
2370 | a TLS session. | |
2371 | ||
2372 | Arguments: | |
83da1223 | 2373 | require_ciphers list of allowed ciphers or NULL |
cf0c6164 | 2374 | errstr pointer to error string |
059ec3d9 PH |
2375 | |
2376 | Returns: OK on success | |
2377 | DEFER for errors before the start of the negotiation | |
4c04137d | 2378 | FAIL for errors during the negotiation; the server can't |
059ec3d9 PH |
2379 | continue running. |
2380 | */ | |
2381 | ||
2382 | int | |
cf0c6164 | 2383 | tls_server_start(const uschar * require_ciphers, uschar ** errstr) |
059ec3d9 PH |
2384 | { |
2385 | int rc; | |
cf0c6164 | 2386 | exim_gnutls_state_st * state = NULL; |
059ec3d9 PH |
2387 | |
2388 | /* Check for previous activation */ | |
74f1a423 | 2389 | if (tls_in.active.sock >= 0) |
059ec3d9 | 2390 | { |
48224640 | 2391 | tls_error(US"STARTTLS received after TLS started", US "", NULL, errstr); |
925ac8e4 | 2392 | smtp_printf("554 Already in TLS\r\n", FALSE); |
059ec3d9 PH |
2393 | return FAIL; |
2394 | } | |
2395 | ||
2396 | /* Initialize the library. If it fails, it will already have logged the error | |
2397 | and sent an SMTP response. */ | |
2398 | ||
17c76198 | 2399 | DEBUG(D_tls) debug_printf("initialising GnuTLS as a server\n"); |
059ec3d9 | 2400 | |
d85cdeb5 JH |
2401 | { |
2402 | #ifdef MEASURE_TIMING | |
2403 | struct timeval t0; | |
2404 | gettimeofday(&t0, NULL); | |
2405 | #endif | |
2406 | ||
2407 | if ((rc = tls_init(NULL, tls_certificate, tls_privatekey, | |
2408 | NULL, tls_verify_certificates, tls_crl, | |
2409 | require_ciphers, &state, &tls_in, errstr)) != OK) return rc; | |
2410 | ||
2411 | #ifdef MEASURE_TIMING | |
2412 | report_time_since(&t0, US"server tls_init (delta)"); | |
2413 | #endif | |
2414 | } | |
059ec3d9 | 2415 | |
b10c87b3 JH |
2416 | #ifdef EXPERIMENTAL_TLS_RESUME |
2417 | tls_server_resume_prehandshake(state); | |
2418 | #endif | |
2419 | ||
059ec3d9 PH |
2420 | /* If this is a host for which certificate verification is mandatory or |
2421 | optional, set up appropriately. */ | |
2422 | ||
059ec3d9 | 2423 | if (verify_check_host(&tls_verify_hosts) == OK) |
17c76198 | 2424 | { |
e51c7be2 JH |
2425 | DEBUG(D_tls) |
2426 | debug_printf("TLS: a client certificate will be required.\n"); | |
17c76198 PP |
2427 | state->verify_requirement = VERIFY_REQUIRED; |
2428 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); | |
2429 | } | |
059ec3d9 | 2430 | else if (verify_check_host(&tls_try_verify_hosts) == OK) |
17c76198 | 2431 | { |
e51c7be2 JH |
2432 | DEBUG(D_tls) |
2433 | debug_printf("TLS: a client certificate will be requested but not required.\n"); | |
17c76198 PP |
2434 | state->verify_requirement = VERIFY_OPTIONAL; |
2435 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST); | |
2436 | } | |
2437 | else | |
2438 | { | |
e51c7be2 JH |
2439 | DEBUG(D_tls) |
2440 | debug_printf("TLS: a client certificate will not be requested.\n"); | |
17c76198 PP |
2441 | state->verify_requirement = VERIFY_NONE; |
2442 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); | |
2443 | } | |
059ec3d9 | 2444 | |
0cbf2b82 | 2445 | #ifndef DISABLE_EVENT |
723fe533 JH |
2446 | if (event_action) |
2447 | { | |
2448 | state->event_action = event_action; | |
2449 | gnutls_session_set_ptr(state->session, state); | |
2450 | gnutls_certificate_set_verify_function(state->x509_cred, verify_cb); | |
2451 | } | |
2452 | #endif | |
2453 | ||
17c76198 PP |
2454 | /* Register SNI handling; always, even if not in tls_certificate, so that the |
2455 | expansion variable $tls_sni is always available. */ | |
059ec3d9 | 2456 | |
17c76198 PP |
2457 | gnutls_handshake_set_post_client_hello_function(state->session, |
2458 | exim_sni_handling_cb); | |
059ec3d9 PH |
2459 | |
2460 | /* Set context and tell client to go ahead, except in the case of TLS startup | |
2461 | on connection, where outputting anything now upsets the clients and tends to | |
2462 | make them disconnect. We need to have an explicit fflush() here, to force out | |
2463 | the response. Other smtp_printf() calls do not need it, because in non-TLS | |
2464 | mode, the fflush() happens when smtp_getc() is called. */ | |
2465 | ||
817d9f57 | 2466 | if (!state->tlsp->on_connect) |
059ec3d9 | 2467 | { |
925ac8e4 | 2468 | smtp_printf("220 TLS go ahead\r\n", FALSE); |
9d1c15ef | 2469 | fflush(smtp_out); |
059ec3d9 PH |
2470 | } |
2471 | ||
2472 | /* Now negotiate the TLS session. We put our own timer on it, since it seems | |
8008accd JH |
2473 | that the GnuTLS library doesn't. |
2474 | From 3.1.0 there is gnutls_handshake_set_timeout() - but it requires you | |
2475 | to set (and clear down afterwards) up a pull-timeout callback function that does | |
2476 | a select, so we're no better off unless avoiding signals becomes an issue. */ | |
059ec3d9 | 2477 | |
17c76198 | 2478 | gnutls_transport_set_ptr2(state->session, |
27f19eb4 JH |
2479 | (gnutls_transport_ptr_t)(long) fileno(smtp_in), |
2480 | (gnutls_transport_ptr_t)(long) fileno(smtp_out)); | |
17c76198 PP |
2481 | state->fd_in = fileno(smtp_in); |
2482 | state->fd_out = fileno(smtp_out); | |
059ec3d9 PH |
2483 | |
2484 | sigalrm_seen = FALSE; | |
c2a1bba0 | 2485 | if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); |
17c76198 | 2486 | do |
17c76198 | 2487 | rc = gnutls_handshake(state->session); |
157a7880 | 2488 | while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen); |
c2a1bba0 | 2489 | ALARM_CLR(0); |
059ec3d9 | 2490 | |
17c76198 | 2491 | if (rc != GNUTLS_E_SUCCESS) |
059ec3d9 | 2492 | { |
059ec3d9 PH |
2493 | /* It seems that, except in the case of a timeout, we have to close the |
2494 | connection right here; otherwise if the other end is running OpenSSL it hangs | |
2495 | until the server times out. */ | |
2496 | ||
60d10ce7 | 2497 | if (sigalrm_seen) |
ad7fc6eb | 2498 | { |
48224640 | 2499 | tls_error(US"gnutls_handshake", US"timed out", NULL, errstr); |
ad7fc6eb JH |
2500 | gnutls_db_remove_session(state->session); |
2501 | } | |
60d10ce7 | 2502 | else |
059ec3d9 | 2503 | { |
452a164f | 2504 | tls_error_gnu(US"gnutls_handshake", rc, NULL, errstr); |
f5d25c2b | 2505 | (void) gnutls_alert_send_appropriate(state->session, rc); |
ad7fc6eb | 2506 | gnutls_deinit(state->session); |
ed62aae3 | 2507 | gnutls_certificate_free_credentials(state->x509_cred); |
60d10ce7 | 2508 | millisleep(500); |
ad7fc6eb | 2509 | shutdown(state->fd_out, SHUT_WR); |
d7978c0f | 2510 | for (int i = 1024; fgetc(smtp_in) != EOF && i > 0; ) i--; /* drain skt */ |
f1e894f3 PH |
2511 | (void)fclose(smtp_out); |
2512 | (void)fclose(smtp_in); | |
60d10ce7 | 2513 | smtp_out = smtp_in = NULL; |
059ec3d9 PH |
2514 | } |
2515 | ||
2516 | return FAIL; | |
2517 | } | |
2518 | ||
b10c87b3 JH |
2519 | #ifdef EXPERIMENTAL_TLS_RESUME |
2520 | tls_server_resume_posthandshake(state); | |
2521 | #endif | |
2522 | ||
dc6d1769 | 2523 | DEBUG(D_tls) post_handshake_debug(state); |
059ec3d9 | 2524 | |
17c76198 PP |
2525 | /* Verify after the fact */ |
2526 | ||
899b8bbc | 2527 | if (!verify_certificate(state, errstr)) |
059ec3d9 | 2528 | { |
9d1c15ef | 2529 | if (state->verify_requirement != VERIFY_OPTIONAL) |
17c76198 | 2530 | { |
cf0c6164 | 2531 | (void) tls_error(US"certificate verification failed", *errstr, NULL, errstr); |
9d1c15ef | 2532 | return FAIL; |
17c76198 | 2533 | } |
9d1c15ef JH |
2534 | DEBUG(D_tls) |
2535 | debug_printf("TLS: continuing on only because verification was optional, after: %s\n", | |
cf0c6164 | 2536 | *errstr); |
059ec3d9 PH |
2537 | } |
2538 | ||
17c76198 PP |
2539 | /* Sets various Exim expansion variables; always safe within server */ |
2540 | ||
9d1c15ef | 2541 | extract_exim_vars_from_tls_state(state); |
059ec3d9 PH |
2542 | |
2543 | /* TLS has been set up. Adjust the input functions to read via TLS, | |
2544 | and initialize appropriately. */ | |
2545 | ||
17c76198 | 2546 | state->xfer_buffer = store_malloc(ssl_xfer_buffer_size); |
059ec3d9 PH |
2547 | |
2548 | receive_getc = tls_getc; | |
0d81dabc | 2549 | receive_getbuf = tls_getbuf; |
584e96c6 | 2550 | receive_get_cache = tls_get_cache; |
059ec3d9 PH |
2551 | receive_ungetc = tls_ungetc; |
2552 | receive_feof = tls_feof; | |
2553 | receive_ferror = tls_ferror; | |
58eb016e | 2554 | receive_smtp_buffered = tls_smtp_buffered; |
059ec3d9 | 2555 | |
059ec3d9 PH |
2556 | return OK; |
2557 | } | |
2558 | ||
2559 | ||
2560 | ||
2561 | ||
aa2a70ba JH |
2562 | static void |
2563 | tls_client_setup_hostname_checks(host_item * host, exim_gnutls_state_st * state, | |
2564 | smtp_transport_options_block * ob) | |
2565 | { | |
3fb3231c | 2566 | if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK) |
aa2a70ba | 2567 | { |
4af0d74a | 2568 | state->exp_tls_verify_cert_hostnames = |
8c5d388a | 2569 | #ifdef SUPPORT_I18N |
4af0d74a JH |
2570 | string_domain_utf8_to_alabel(host->name, NULL); |
2571 | #else | |
2572 | host->name; | |
2573 | #endif | |
aa2a70ba JH |
2574 | DEBUG(D_tls) |
2575 | debug_printf("TLS: server cert verification includes hostname: \"%s\".\n", | |
2576 | state->exp_tls_verify_cert_hostnames); | |
2577 | } | |
2578 | } | |
aa2a70ba JH |
2579 | |
2580 | ||
899b8bbc JH |
2581 | |
2582 | ||
2583 | #ifdef SUPPORT_DANE | |
2584 | /* Given our list of RRs from the TLSA lookup, build a lookup block in | |
2585 | GnuTLS-DANE's preferred format. Hang it on the state str for later | |
2586 | use in DANE verification. | |
2587 | ||
2588 | We point at the dnsa data not copy it, so it must remain valid until | |
2589 | after verification is done.*/ | |
2590 | ||
3674140c | 2591 | static BOOL |
899b8bbc JH |
2592 | dane_tlsa_load(exim_gnutls_state_st * state, dns_answer * dnsa) |
2593 | { | |
899b8bbc JH |
2594 | dns_scan dnss; |
2595 | int i; | |
2596 | const char ** dane_data; | |
2597 | int * dane_data_len; | |
2598 | ||
d7978c0f JH |
2599 | i = 1; |
2600 | for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; | |
899b8bbc JH |
2601 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) |
2602 | ) if (rr->type == T_TLSA) i++; | |
2603 | ||
f3ebb786 JH |
2604 | dane_data = store_get(i * sizeof(uschar *), FALSE); |
2605 | dane_data_len = store_get(i * sizeof(int), FALSE); | |
899b8bbc | 2606 | |
d7978c0f JH |
2607 | i = 0; |
2608 | for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; | |
899b8bbc | 2609 | rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) |
1b76ad22 | 2610 | ) if (rr->type == T_TLSA && rr->size > 3) |
899b8bbc JH |
2611 | { |
2612 | const uschar * p = rr->data; | |
f3ebb786 | 2613 | /*XXX need somehow to mark rr and its data as tainted. Doues this mean copying it? */ |
3674140c JH |
2614 | uint8_t usage = p[0], sel = p[1], type = p[2]; |
2615 | ||
2616 | DEBUG(D_tls) | |
2617 | debug_printf("TLSA: %d %d %d size %d\n", usage, sel, type, rr->size); | |
2618 | ||
94c13285 JH |
2619 | if ( (usage != DANESSL_USAGE_DANE_TA && usage != DANESSL_USAGE_DANE_EE) |
2620 | || (sel != 0 && sel != 1) | |
2621 | ) | |
2622 | continue; | |
3674140c JH |
2623 | switch(type) |
2624 | { | |
2625 | case 0: /* Full: cannot check at present */ | |
2626 | break; | |
2627 | case 1: if (rr->size != 3 + 256/8) continue; /* sha2-256 */ | |
2628 | break; | |
2629 | case 2: if (rr->size != 3 + 512/8) continue; /* sha2-512 */ | |
2630 | break; | |
2631 | default: continue; | |
2632 | } | |
899b8bbc JH |
2633 | |
2634 | tls_out.tlsa_usage |= 1<<usage; | |
48224640 | 2635 | dane_data[i] = CS p; |
899b8bbc JH |
2636 | dane_data_len[i++] = rr->size; |
2637 | } | |
3674140c JH |
2638 | |
2639 | if (!i) return FALSE; | |
2640 | ||
899b8bbc JH |
2641 | dane_data[i] = NULL; |
2642 | dane_data_len[i] = 0; | |
2643 | ||
2644 | state->dane_data = (char * const *)dane_data; | |
2645 | state->dane_data_len = dane_data_len; | |
3674140c | 2646 | return TRUE; |
899b8bbc JH |
2647 | } |
2648 | #endif | |
2649 | ||
2650 | ||
2651 | ||
b10c87b3 JH |
2652 | #ifdef EXPERIMENTAL_TLS_RESUME |
2653 | /* On the client, get any stashed session for the given IP from hints db | |
2654 | and apply it to the ssl-connection for attempted resumption. Although | |
2655 | there is a gnutls_session_ticket_enable_client() interface it is | |
2656 | documented as unnecessary (as of 3.6.7) as "session tickets are emabled | |
2657 | by deafult". There seems to be no way to disable them, so even hosts not | |
2658 | enabled by the transport option will be sent a ticket request. We will | |
2659 | however avoid storing and retrieving session information. */ | |
2660 | ||
2661 | static void | |
2662 | tls_retrieve_session(tls_support * tlsp, gnutls_session_t session, | |
2663 | host_item * host, smtp_transport_options_block * ob) | |
2664 | { | |
2665 | tlsp->resumption = RESUME_SUPPORTED; | |
2666 | if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, host) == OK) | |
2667 | { | |
2668 | dbdata_tls_session * dt; | |
2669 | int len, rc; | |
2670 | open_db dbblock, * dbm_file; | |
2671 | ||
2672 | DEBUG(D_tls) | |
2673 | debug_printf("check for resumable session for %s\n", host->address); | |
2674 | tlsp->host_resumable = TRUE; | |
2675 | tlsp->resumption |= RESUME_CLIENT_REQUESTED; | |
2676 | if ((dbm_file = dbfn_open(US"tls", O_RDONLY, &dbblock, FALSE, FALSE))) | |
2677 | { | |
dea4b568 JH |
2678 | /* Key for the db is the IP. We'd like to filter the retrieved session |
2679 | for ticket advisory expiry, but 3.6.1 seems to give no access to that */ | |
2680 | ||
b10c87b3 JH |
2681 | if ((dt = dbfn_read_with_length(dbm_file, host->address, &len))) |
2682 | if (!(rc = gnutls_session_set_data(session, | |
2683 | CUS dt->session, (size_t)len - sizeof(dbdata_tls_session)))) | |
2684 | { | |
2685 | DEBUG(D_tls) debug_printf("good session\n"); | |
2686 | tlsp->resumption |= RESUME_CLIENT_SUGGESTED; | |
2687 | } | |
2688 | else DEBUG(D_tls) debug_printf("setting session resumption data: %s\n", | |
2689 | US gnutls_strerror(rc)); | |
2690 | dbfn_close(dbm_file); | |
2691 | } | |
2692 | } | |
2693 | } | |
2694 | ||
2695 | ||
2696 | static void | |
2697 | tls_save_session(tls_support * tlsp, gnutls_session_t session, const host_item * host) | |
2698 | { | |
2699 | /* TLS 1.2 - we get both the callback and the direct posthandshake call, | |
2700 | but this flag is not set until the second. TLS 1.3 it's the other way about. | |
2701 | Keep both calls as the session data cannot be extracted before handshake | |
2702 | completes. */ | |
2703 | ||
2704 | if (gnutls_session_get_flags(session) & GNUTLS_SFLAGS_SESSION_TICKET) | |
2705 | { | |
2706 | gnutls_datum_t tkt; | |
2707 | int rc; | |
2708 | ||
2709 | DEBUG(D_tls) debug_printf("server offered session ticket\n"); | |
2710 | tlsp->ticket_received = TRUE; | |
2711 | tlsp->resumption |= RESUME_SERVER_TICKET; | |
2712 | ||
2713 | if (tlsp->host_resumable) | |
2714 | if (!(rc = gnutls_session_get_data2(session, &tkt))) | |
2715 | { | |
2716 | open_db dbblock, * dbm_file; | |
2717 | int dlen = sizeof(dbdata_tls_session) + tkt.size; | |
f3ebb786 | 2718 | dbdata_tls_session * dt = store_get(dlen, TRUE); |
b10c87b3 JH |
2719 | |
2720 | DEBUG(D_tls) debug_printf("session data size %u\n", (unsigned)tkt.size); | |
2721 | memcpy(dt->session, tkt.data, tkt.size); | |
2722 | gnutls_free(tkt.data); | |
2723 | ||
2724 | if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE))) | |
2725 | { | |
2726 | /* key for the db is the IP */ | |
2727 | dbfn_delete(dbm_file, host->address); | |
2728 | dbfn_write(dbm_file, host->address, dt, dlen); | |
2729 | dbfn_close(dbm_file); | |
2730 | ||
2731 | DEBUG(D_tls) | |
2732 | debug_printf("wrote session db (len %u)\n", (unsigned)dlen); | |
2733 | } | |
2734 | } | |
2735 | else DEBUG(D_tls) | |
2736 | debug_printf("extract session data: %s\n", US gnutls_strerror(rc)); | |
2737 | } | |
2738 | } | |
2739 | ||
2740 | ||
2741 | /* With a TLS1.3 session, the ticket(s) are not seen until | |
2742 | the first data read is attempted. And there's often two of them. | |
2743 | Pick them up with this callback. We are also called for 1.2 | |
2744 | but we do nothing. | |
2745 | */ | |
2746 | static int | |
2747 | tls_client_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when, | |
2748 | unsigned incoming, const gnutls_datum_t * msg) | |
2749 | { | |
2750 | exim_gnutls_state_st * state = gnutls_session_get_ptr(sess); | |
2751 | tls_support * tlsp = state->tlsp; | |
2752 | ||
2753 | DEBUG(D_tls) debug_printf("newticket cb\n"); | |
2754 | ||
2755 | if (!tlsp->ticket_received) | |
2756 | tls_save_session(tlsp, sess, state->host); | |
2757 | return 0; | |
2758 | } | |
2759 | ||
2760 | ||
2761 | static void | |
2762 | tls_client_resume_prehandshake(exim_gnutls_state_st * state, | |
2763 | tls_support * tlsp, host_item * host, | |
2764 | smtp_transport_options_block * ob) | |
2765 | { | |
2766 | gnutls_session_set_ptr(state->session, state); | |
2767 | gnutls_handshake_set_hook_function(state->session, | |
2768 | GNUTLS_HANDSHAKE_NEW_SESSION_TICKET, GNUTLS_HOOK_POST, tls_client_ticket_cb); | |
2769 | ||
2770 | tls_retrieve_session(tlsp, state->session, host, ob); | |
2771 | } | |
2772 | ||
2773 | static void | |
2774 | tls_client_resume_posthandshake(exim_gnutls_state_st * state, | |
2775 | tls_support * tlsp, host_item * host) | |
2776 | { | |
2777 | if (gnutls_session_is_resumed(state->session)) | |
2778 | { | |
2779 | DEBUG(D_tls) debug_printf("Session resumed\n"); | |
2780 | tlsp->resumption |= RESUME_USED; | |
2781 | } | |
2782 | ||
2783 | tls_save_session(tlsp, state->session, host); | |
2784 | } | |
2785 | #endif /* EXPERIMENTAL_TLS_RESUME */ | |
2786 | ||
2787 | ||
059ec3d9 PH |
2788 | /************************************************* |
2789 | * Start a TLS session in a client * | |
2790 | *************************************************/ | |
2791 | ||
2792 | /* Called from the smtp transport after STARTTLS has been accepted. | |
2793 | ||
2794 | Arguments: | |
c05bdbd6 JH |
2795 | cctx connection context |
2796 | conn_args connection details | |
2797 | cookie datum for randomness (not used) | |
2798 | tlsp record details of channel configuration here; must be non-NULL | |
2799 | errstr error string pointer | |
2800 | ||
2801 | Returns: TRUE for success with TLS session context set in smtp context, | |
2802 | FALSE on error | |
059ec3d9 PH |
2803 | */ |
2804 | ||
c05bdbd6 JH |
2805 | BOOL |
2806 | tls_client_start(client_conn_ctx * cctx, smtp_connect_args * conn_args, | |
2807 | void * cookie ARG_UNUSED, | |
2808 | tls_support * tlsp, uschar ** errstr) | |
059ec3d9 | 2809 | { |
c05bdbd6 JH |
2810 | host_item * host = conn_args->host; /* for msgs and option-tests */ |
2811 | transport_instance * tb = conn_args->tblock; /* always smtp or NULL */ | |
2812 | smtp_transport_options_block * ob = tb | |
afdb5e9c JH |
2813 | ? (smtp_transport_options_block *)tb->options_block |
2814 | : &smtp_transport_option_defaults; | |
059ec3d9 | 2815 | int rc; |
899b8bbc | 2816 | exim_gnutls_state_st * state = NULL; |
c05bdbd6 | 2817 | uschar * cipher_list = NULL; |
74f1a423 | 2818 | |
f2de3a33 | 2819 | #ifndef DISABLE_OCSP |
5130845b | 2820 | BOOL require_ocsp = |
3fb3231c | 2821 | verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK; |
44662487 | 2822 | BOOL request_ocsp = require_ocsp ? TRUE |
3fb3231c | 2823 | : verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK; |
2b4a568d | 2824 | #endif |
059ec3d9 | 2825 | |
c05bdbd6 | 2826 | DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", cctx->sock); |
059ec3d9 | 2827 | |
5ec37a55 | 2828 | #ifdef SUPPORT_DANE |
c05bdbd6 JH |
2829 | /* If dane is flagged, have either request or require dane for this host, and |
2830 | a TLSA record found. Therefore, dane verify required. Which implies cert must | |
2831 | be requested and supplied, dane verify must pass, and cert verify irrelevant | |
2832 | (incl. hostnames), and (caller handled) require_tls */ | |
2833 | ||
2834 | if (conn_args->dane && ob->dane_require_tls_ciphers) | |
5ec37a55 PP |
2835 | { |
2836 | /* not using expand_check_tlsvar because not yet in state */ | |
2837 | if (!expand_check(ob->dane_require_tls_ciphers, US"dane_require_tls_ciphers", | |
2838 | &cipher_list, errstr)) | |
c05bdbd6 | 2839 | return FALSE; |
cf260049 JH |
2840 | cipher_list = cipher_list && *cipher_list |
2841 | ? ob->dane_require_tls_ciphers : ob->tls_require_ciphers; | |
5ec37a55 PP |
2842 | } |
2843 | #endif | |
2844 | ||
2845 | if (!cipher_list) | |
2846 | cipher_list = ob->tls_require_ciphers; | |
2847 | ||
d85cdeb5 JH |
2848 | { |
2849 | #ifdef MEASURE_TIMING | |
2850 | struct timeval t0; | |
2851 | gettimeofday(&t0, NULL); | |
2852 | #endif | |
2853 | ||
2854 | if (tls_init(host, ob->tls_certificate, ob->tls_privatekey, | |
2855 | ob->tls_sni, ob->tls_verify_certificates, ob->tls_crl, | |
2856 | cipher_list, &state, tlsp, errstr) != OK) | |
2857 | return FALSE; | |
2858 | ||
2859 | #ifdef MEASURE_TIMING | |
2860 | report_time_since(&t0, US"client tls_init (delta)"); | |
2861 | #endif | |
2862 | } | |
059ec3d9 | 2863 | |
54c90be1 | 2864 | { |
65867078 JH |
2865 | int dh_min_bits = ob->tls_dh_min_bits; |
2866 | if (dh_min_bits < EXIM_CLIENT_DH_MIN_MIN_BITS) | |
2867 | { | |
2868 | DEBUG(D_tls) | |
2869 | debug_printf("WARNING: tls_dh_min_bits far too low," | |
2870 | " clamping %d up to %d\n", | |
2871 | dh_min_bits, EXIM_CLIENT_DH_MIN_MIN_BITS); | |
2872 | dh_min_bits = EXIM_CLIENT_DH_MIN_MIN_BITS; | |
2873 | } | |
54c90be1 | 2874 | |
65867078 JH |
2875 | DEBUG(D_tls) debug_printf("Setting D-H prime minimum" |
2876 | " acceptable bits to %d\n", | |
2877 | dh_min_bits); | |
2878 | gnutls_dh_set_prime_bits(state->session, dh_min_bits); | |
2879 | } | |
83da1223 | 2880 | |
94431adb | 2881 | /* Stick to the old behaviour for compatibility if tls_verify_certificates is |
2b4a568d JH |
2882 | set but both tls_verify_hosts and tls_try_verify_hosts are unset. Check only |
2883 | the specified host patterns if one of them is defined */ | |
2884 | ||
899b8bbc | 2885 | #ifdef SUPPORT_DANE |
c05bdbd6 | 2886 | if (conn_args->dane && dane_tlsa_load(state, &conn_args->tlsa_dnsa)) |
899b8bbc JH |
2887 | { |
2888 | DEBUG(D_tls) | |
2889 | debug_printf("TLS: server certificate DANE required.\n"); | |
2890 | state->verify_requirement = VERIFY_DANE; | |
2891 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); | |
899b8bbc JH |
2892 | } |
2893 | else | |
2894 | #endif | |
2895 | if ( ( state->exp_tls_verify_certificates | |
2896 | && !ob->tls_verify_hosts | |
2897 | && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) | |
2898 | ) | |
3fb3231c | 2899 | || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK |
899b8bbc | 2900 | ) |
17c76198 | 2901 | { |
aa2a70ba | 2902 | tls_client_setup_hostname_checks(host, state, ob); |
aa2a70ba JH |
2903 | DEBUG(D_tls) |
2904 | debug_printf("TLS: server certificate verification required.\n"); | |
2905 | state->verify_requirement = VERIFY_REQUIRED; | |
52f93eed WB |
2906 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); |
2907 | } | |
3fb3231c | 2908 | else if (verify_check_given_host(CUSS &ob->tls_try_verify_hosts, host) == OK) |
52f93eed | 2909 | { |
aa2a70ba | 2910 | tls_client_setup_hostname_checks(host, state, ob); |
e51c7be2 JH |
2911 | DEBUG(D_tls) |
2912 | debug_printf("TLS: server certificate verification optional.\n"); | |
52f93eed | 2913 | state->verify_requirement = VERIFY_OPTIONAL; |
17c76198 PP |
2914 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST); |
2915 | } | |
2916 | else | |
2917 | { | |
e51c7be2 JH |
2918 | DEBUG(D_tls) |
2919 | debug_printf("TLS: server certificate verification not required.\n"); | |
52f93eed WB |
2920 | state->verify_requirement = VERIFY_NONE; |
2921 | gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); | |
17c76198 | 2922 | } |
059ec3d9 | 2923 | |
f2de3a33 JH |
2924 | #ifndef DISABLE_OCSP |
2925 | /* supported since GnuTLS 3.1.3 */ | |
44662487 | 2926 | if (request_ocsp) |
9d1c15ef JH |
2927 | { |
2928 | DEBUG(D_tls) debug_printf("TLS: will request OCSP stapling\n"); | |
65867078 JH |
2929 | if ((rc = gnutls_ocsp_status_request_enable_client(state->session, |
2930 | NULL, 0, NULL)) != OK) | |
74f1a423 | 2931 | { |
452a164f | 2932 | tls_error_gnu(US"cert-status-req", rc, state->host, errstr); |
c05bdbd6 | 2933 | return FALSE; |
74f1a423 JH |
2934 | } |
2935 | tlsp->ocsp = OCSP_NOT_RESP; | |
9d1c15ef | 2936 | } |
2b4a568d JH |
2937 | #endif |
2938 | ||
b10c87b3 JH |
2939 | #ifdef EXPERIMENTAL_TLS_RESUME |
2940 | tls_client_resume_prehandshake(state, tlsp, host, ob); | |
2941 | #endif | |
2942 | ||
0cbf2b82 | 2943 | #ifndef DISABLE_EVENT |
afdb5e9c | 2944 | if (tb && tb->event_action) |
a7538db1 | 2945 | { |
774ef2d7 | 2946 | state->event_action = tb->event_action; |
a7538db1 | 2947 | gnutls_session_set_ptr(state->session, state); |
723fe533 | 2948 | gnutls_certificate_set_verify_function(state->x509_cred, verify_cb); |
a7538db1 JH |
2949 | } |
2950 | #endif | |
2951 | ||
c05bdbd6 JH |
2952 | gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr_t)(long) cctx->sock); |
2953 | state->fd_in = cctx->sock; | |
2954 | state->fd_out = cctx->sock; | |
059ec3d9 | 2955 | |
9d1c15ef | 2956 | DEBUG(D_tls) debug_printf("about to gnutls_handshake\n"); |
059ec3d9 PH |
2957 | /* There doesn't seem to be a built-in timeout on connection. */ |
2958 | ||
2959 | sigalrm_seen = FALSE; | |
c2a1bba0 | 2960 | ALARM(ob->command_timeout); |
17c76198 | 2961 | do |
17c76198 | 2962 | rc = gnutls_handshake(state->session); |
f1fed05b | 2963 | while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen); |
c2a1bba0 | 2964 | ALARM_CLR(0); |
059ec3d9 | 2965 | |
4fe99a6c | 2966 | if (rc != GNUTLS_E_SUCCESS) |
74f1a423 | 2967 | { |
60d10ce7 JH |
2968 | if (sigalrm_seen) |
2969 | { | |
2970 | gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_USER_CANCELED); | |
48224640 | 2971 | tls_error(US"gnutls_handshake", US"timed out", state->host, errstr); |
60d10ce7 JH |
2972 | } |
2973 | else | |
452a164f | 2974 | tls_error_gnu(US"gnutls_handshake", rc, state->host, errstr); |
c05bdbd6 | 2975 | return FALSE; |
74f1a423 | 2976 | } |
4fe99a6c | 2977 | |
dc6d1769 | 2978 | DEBUG(D_tls) post_handshake_debug(state); |
059ec3d9 | 2979 | |
17c76198 | 2980 | /* Verify late */ |
059ec3d9 | 2981 | |
899b8bbc | 2982 | if (!verify_certificate(state, errstr)) |
74f1a423 JH |
2983 | { |
2984 | tls_error(US"certificate verification failed", *errstr, state->host, errstr); | |
c05bdbd6 | 2985 | return FALSE; |
74f1a423 | 2986 | } |
059ec3d9 | 2987 | |
f2de3a33 | 2988 | #ifndef DISABLE_OCSP |
7a501c87 | 2989 | if (request_ocsp) |
2b4a568d JH |
2990 | { |
2991 | DEBUG(D_tls) | |
2992 | { | |
2993 | gnutls_datum_t stapling; | |
2994 | gnutls_ocsp_resp_t resp; | |
2995 | gnutls_datum_t printed; | |
e326959e JH |
2996 | unsigned idx = 0; |
2997 | ||
2998 | for (; | |
2999 | # ifdef GNUTLS_OCSP_STATUS_REQUEST_GET2 | |
3000 | (rc = gnutls_ocsp_status_request_get2(state->session, idx, &stapling)) == 0; | |
3001 | #else | |
3002 | (rc = gnutls_ocsp_status_request_get(state->session, &stapling)) == 0; | |
3003 | #endif | |
3004 | idx++) | |
3005 | if ( (rc= gnutls_ocsp_resp_init(&resp)) == 0 | |
3006 | && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0 | |
3007 | && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_COMPACT, &printed)) == 0 | |
3008 | ) | |
3009 | { | |
3010 | debug_printf("%.4096s", printed.data); | |
3011 | gnutls_free(printed.data); | |
3012 | } | |
3013 | else | |
3014 | (void) tls_error_gnu(US"ocsp decode", rc, state->host, errstr); | |
3015 | if (idx == 0 && rc) | |
452a164f | 3016 | (void) tls_error_gnu(US"ocsp decode", rc, state->host, errstr); |
2b4a568d JH |
3017 | } |
3018 | ||
2b4a568d | 3019 | if (gnutls_ocsp_status_request_is_checked(state->session, 0) == 0) |
018058b2 | 3020 | { |
74f1a423 JH |
3021 | tlsp->ocsp = OCSP_FAILED; |
3022 | tls_error(US"certificate status check failed", NULL, state->host, errstr); | |
7a501c87 JH |
3023 | if (require_ocsp) |
3024 | return FALSE; | |
3025 | } | |
3026 | else | |
3027 | { | |
3028 | DEBUG(D_tls) debug_printf("Passed OCSP checking\n"); | |
3029 | tlsp->ocsp = OCSP_VFIED; | |
018058b2 | 3030 | } |
2b4a568d JH |
3031 | } |
3032 | #endif | |
3033 | ||
b10c87b3 JH |
3034 | #ifdef EXPERIMENTAL_TLS_RESUME |
3035 | tls_client_resume_posthandshake(state, tlsp, host); | |
3036 | #endif | |
059ec3d9 | 3037 | |
4fe99a6c | 3038 | /* Sets various Exim expansion variables; may need to adjust for ACL callouts */ |
059ec3d9 | 3039 | |
9d1c15ef | 3040 | extract_exim_vars_from_tls_state(state); |
059ec3d9 | 3041 | |
c05bdbd6 JH |
3042 | cctx->tls_ctx = state; |
3043 | return TRUE; | |
059ec3d9 PH |
3044 | } |
3045 | ||
3046 | ||
3047 | ||
17c76198 | 3048 | |
059ec3d9 | 3049 | /************************************************* |
17c76198 | 3050 | * Close down a TLS session * |
059ec3d9 PH |
3051 | *************************************************/ |
3052 | ||
17c76198 PP |
3053 | /* This is also called from within a delivery subprocess forked from the |
3054 | daemon, to shut down the TLS library, without actually doing a shutdown (which | |
3055 | would tamper with the TLS session in the parent process). | |
059ec3d9 | 3056 | |
dec766a1 | 3057 | Arguments: |
74f1a423 | 3058 | ct_ctx client context pointer, or NULL for the one global server context |
dec766a1 | 3059 | shutdown 1 if TLS close-alert is to be sent, |
afdb5e9c | 3060 | 2 if also response to be waited for |
dec766a1 | 3061 | |
17c76198 | 3062 | Returns: nothing |
059ec3d9 PH |
3063 | */ |
3064 | ||
17c76198 | 3065 | void |
74f1a423 | 3066 | tls_close(void * ct_ctx, int shutdown) |
059ec3d9 | 3067 | { |
74f1a423 | 3068 | exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; |
bd231acd | 3069 | tls_support * tlsp = state->tlsp; |
059ec3d9 | 3070 | |
bd231acd | 3071 | if (!tlsp || tlsp->active.sock < 0) return; /* TLS was not active */ |
17c76198 PP |
3072 | |
3073 | if (shutdown) | |
3074 | { | |
dec766a1 WB |
3075 | DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n", |
3076 | shutdown > 1 ? " (with response-wait)" : ""); | |
3077 | ||
c2a1bba0 | 3078 | ALARM(2); |
dec766a1 | 3079 | gnutls_bye(state->session, shutdown > 1 ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR); |
c2a1bba0 | 3080 | ALARM_CLR(0); |
17c76198 PP |
3081 | } |
3082 | ||
bd231acd JH |
3083 | if (!ct_ctx) /* server */ |
3084 | { | |
3085 | receive_getc = smtp_getc; | |
3086 | receive_getbuf = smtp_getbuf; | |
3087 | receive_get_cache = smtp_get_cache; | |
3088 | receive_ungetc = smtp_ungetc; | |
3089 | receive_feof = smtp_feof; | |
3090 | receive_ferror = smtp_ferror; | |
3091 | receive_smtp_buffered = smtp_buffered; | |
3092 | } | |
3093 | ||
17c76198 | 3094 | gnutls_deinit(state->session); |
ed62aae3 HSHR |
3095 | gnutls_certificate_free_credentials(state->x509_cred); |
3096 | ||
bd231acd JH |
3097 | tlsp->active.sock = -1; |
3098 | tlsp->active.tls_ctx = NULL; | |
3099 | /* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */ | |
b1a32a3c | 3100 | tlsp->channelbinding = NULL; |
bd231acd | 3101 | |
17c76198 | 3102 | |
b808677c | 3103 | if (state->xfer_buffer) store_free(state->xfer_buffer); |
17c76198 | 3104 | memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); |
059ec3d9 PH |
3105 | } |
3106 | ||
3107 | ||
3108 | ||
17c76198 | 3109 | |
0d81dabc JH |
3110 | static BOOL |
3111 | tls_refill(unsigned lim) | |
3112 | { | |
3113 | exim_gnutls_state_st * state = &state_server; | |
3114 | ssize_t inbytes; | |
3115 | ||
3116 | DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(%p, %p, %u)\n", | |
3117 | state->session, state->xfer_buffer, ssl_xfer_buffer_size); | |
3118 | ||
f1fed05b | 3119 | sigalrm_seen = FALSE; |
c2a1bba0 | 3120 | if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); |
4896a319 AM |
3121 | |
3122 | do | |
3123 | inbytes = gnutls_record_recv(state->session, state->xfer_buffer, | |
3124 | MIN(ssl_xfer_buffer_size, lim)); | |
3125 | while (inbytes == GNUTLS_E_AGAIN); | |
3126 | ||
c2a1bba0 | 3127 | if (smtp_receive_timeout > 0) ALARM_CLR(0); |
9723f966 JH |
3128 | |
3129 | if (had_command_timeout) /* set by signal handler */ | |
3130 | smtp_command_timeout_exit(); /* does not return */ | |
3131 | if (had_command_sigterm) | |
3132 | smtp_command_sigterm_exit(); | |
3133 | if (had_data_timeout) | |
3134 | smtp_data_timeout_exit(); | |
3135 | if (had_data_sigint) | |
3136 | smtp_data_sigint_exit(); | |
3137 | ||
3138 | /* Timeouts do not get this far. A zero-byte return appears to mean that the | |
3139 | TLS session has been closed down, not that the socket itself has been closed | |
3140 | down. Revert to non-TLS handling. */ | |
0d81dabc JH |
3141 | |
3142 | if (sigalrm_seen) | |
3143 | { | |
3144 | DEBUG(D_tls) debug_printf("Got tls read timeout\n"); | |
8b77d27a | 3145 | state->xfer_error = TRUE; |
0d81dabc JH |
3146 | return FALSE; |
3147 | } | |
3148 | ||
3149 | else if (inbytes == 0) | |
3150 | { | |
3151 | DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); | |
bd231acd | 3152 | tls_close(NULL, TLS_NO_SHUTDOWN); |
0d81dabc JH |
3153 | return FALSE; |
3154 | } | |
3155 | ||
3156 | /* Handle genuine errors */ | |
3157 | ||
3158 | else if (inbytes < 0) | |
3159 | { | |
95f52235 | 3160 | DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv\n", __FUNCTION__); |
0d81dabc | 3161 | record_io_error(state, (int) inbytes, US"recv", NULL); |
8b77d27a | 3162 | state->xfer_error = TRUE; |
0d81dabc JH |
3163 | return FALSE; |
3164 | } | |
3165 | #ifndef DISABLE_DKIM | |
3166 | dkim_exim_verify_feed(state->xfer_buffer, inbytes); | |
3167 | #endif | |
3168 | state->xfer_buffer_hwm = (int) inbytes; | |
3169 | state->xfer_buffer_lwm = 0; | |
3170 | return TRUE; | |
3171 | } | |
3172 | ||
059ec3d9 PH |
3173 | /************************************************* |
3174 | * TLS version of getc * | |
3175 | *************************************************/ | |
3176 | ||
3177 | /* This gets the next byte from the TLS input buffer. If the buffer is empty, | |
3178 | it refills the buffer via the GnuTLS reading function. | |
817d9f57 | 3179 | Only used by the server-side TLS. |
059ec3d9 | 3180 | |
17c76198 PP |
3181 | This feeds DKIM and should be used for all message-body reads. |
3182 | ||
aded2255 | 3183 | Arguments: lim Maximum amount to read/buffer |
059ec3d9 PH |
3184 | Returns: the next character or EOF |
3185 | */ | |
3186 | ||
3187 | int | |
bd8fbe36 | 3188 | tls_getc(unsigned lim) |
059ec3d9 | 3189 | { |
0d81dabc | 3190 | exim_gnutls_state_st * state = &state_server; |
059ec3d9 | 3191 | |
0d81dabc JH |
3192 | if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) |
3193 | if (!tls_refill(lim)) | |
3194 | return state->xfer_error ? EOF : smtp_getc(lim); | |
ed62aae3 | 3195 | |
0d81dabc | 3196 | /* Something in the buffer; return next uschar */ |
059ec3d9 | 3197 | |
0d81dabc JH |
3198 | return state->xfer_buffer[state->xfer_buffer_lwm++]; |
3199 | } | |
059ec3d9 | 3200 | |
0d81dabc JH |
3201 | uschar * |
3202 | tls_getbuf(unsigned * len) | |
3203 | { | |
3204 | exim_gnutls_state_st * state = &state_server; | |
3205 | unsigned size; | |
3206 | uschar * buf; | |
059ec3d9 | 3207 | |
0d81dabc JH |
3208 | if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) |
3209 | if (!tls_refill(*len)) | |
059ec3d9 | 3210 | { |
0d81dabc JH |
3211 | if (!state->xfer_error) return smtp_getbuf(len); |
3212 | *len = 0; | |
3213 | return NULL; | |
059ec3d9 | 3214 | } |
059ec3d9 | 3215 | |
0d81dabc JH |
3216 | if ((size = state->xfer_buffer_hwm - state->xfer_buffer_lwm) > *len) |
3217 | size = *len; | |
3218 | buf = &state->xfer_buffer[state->xfer_buffer_lwm]; | |
3219 | state->xfer_buffer_lwm += size; | |
3220 | *len = size; | |
3221 | return buf; | |
059ec3d9 PH |
3222 | } |
3223 | ||
0d81dabc | 3224 | |
584e96c6 JH |
3225 | void |
3226 | tls_get_cache() | |
3227 | { | |
9960d1e5 | 3228 | #ifndef DISABLE_DKIM |
584e96c6 JH |
3229 | exim_gnutls_state_st * state = &state_server; |
3230 | int n = state->xfer_buffer_hwm - state->xfer_buffer_lwm; | |
3231 | if (n > 0) | |
3232 | dkim_exim_verify_feed(state->xfer_buffer+state->xfer_buffer_lwm, n); | |
584e96c6 | 3233 | #endif |
9960d1e5 | 3234 | } |
584e96c6 | 3235 | |
059ec3d9 | 3236 | |
925ac8e4 JH |
3237 | BOOL |
3238 | tls_could_read(void) | |
3239 | { | |
3240 | return state_server.xfer_buffer_lwm < state_server.xfer_buffer_hwm | |
3241 | || gnutls_record_check_pending(state_server.session) > 0; | |
3242 | } | |
3243 | ||
3244 | ||
059ec3d9 | 3245 | |
17c76198 | 3246 | |
059ec3d9 PH |
3247 | /************************************************* |
3248 | * Read bytes from TLS channel * | |
3249 | *************************************************/ | |
3250 | ||
17c76198 PP |
3251 | /* This does not feed DKIM, so if the caller uses this for reading message body, |
3252 | then the caller must feed DKIM. | |
817d9f57 | 3253 | |
059ec3d9 | 3254 | Arguments: |
74f1a423 | 3255 | ct_ctx client context pointer, or NULL for the one global server context |
059ec3d9 PH |
3256 | buff buffer of data |
3257 | len size of buffer | |
3258 | ||
3259 | Returns: the number of bytes read | |
afdb5e9c | 3260 | -1 after a failed read, including EOF |
059ec3d9 PH |
3261 | */ |
3262 | ||
3263 | int | |
74f1a423 | 3264 | tls_read(void * ct_ctx, uschar *buff, size_t len) |
059ec3d9 | 3265 | { |
74f1a423 | 3266 | exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; |
17c76198 | 3267 | ssize_t inbytes; |
059ec3d9 | 3268 | |
17c76198 PP |
3269 | if (len > INT_MAX) |
3270 | len = INT_MAX; | |
059ec3d9 | 3271 | |
17c76198 PP |
3272 | if (state->xfer_buffer_lwm < state->xfer_buffer_hwm) |
3273 | DEBUG(D_tls) | |
3274 | debug_printf("*** PROBABLY A BUG *** " \ | |
3275 | "tls_read() called with data in the tls_getc() buffer, %d ignored\n", | |
3276 | state->xfer_buffer_hwm - state->xfer_buffer_lwm); | |
3277 | ||
3278 | DEBUG(D_tls) | |
3279 | debug_printf("Calling gnutls_record_recv(%p, %p, " SIZE_T_FMT ")\n", | |
3280 | state->session, buff, len); | |
3281 | ||
4896a319 AM |
3282 | do |
3283 | inbytes = gnutls_record_recv(state->session, buff, len); | |
3284 | while (inbytes == GNUTLS_E_AGAIN); | |
3285 | ||
059ec3d9 PH |
3286 | if (inbytes > 0) return inbytes; |
3287 | if (inbytes == 0) | |
3288 | { | |
3289 | DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); | |
3290 | } | |
5fd28bb8 | 3291 | else |
4896a319 | 3292 | { |
95f52235 | 3293 | DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv\n", __FUNCTION__); |
4896a319 AM |
3294 | record_io_error(state, (int)inbytes, US"recv", NULL); |
3295 | } | |
059ec3d9 PH |
3296 | |
3297 | return -1; | |
3298 | } | |
3299 | ||
3300 | ||
3301 | ||
17c76198 | 3302 | |
059ec3d9 PH |
3303 | /************************************************* |
3304 | * Write bytes down TLS channel * | |
3305 | *************************************************/ | |
3306 | ||
3307 | /* | |
3308 | Arguments: | |
74f1a423 | 3309 | ct_ctx client context pointer, or NULL for the one global server context |
059ec3d9 PH |
3310 | buff buffer of data |
3311 | len number of bytes | |
925ac8e4 | 3312 | more more data expected soon |
059ec3d9 | 3313 | |
30398c06 JH |
3314 | Calling with len zero and more unset will flush buffered writes. The buff |
3315 | argument can be null for that case. | |
3316 | ||
059ec3d9 PH |
3317 | Returns: the number of bytes after a successful write, |
3318 | -1 after a failed write | |
3319 | */ | |
3320 | ||
3321 | int | |
74f1a423 | 3322 | tls_write(void * ct_ctx, const uschar * buff, size_t len, BOOL more) |
059ec3d9 | 3323 | { |
17c76198 PP |
3324 | ssize_t outbytes; |
3325 | size_t left = len; | |
74f1a423 | 3326 | exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; |
925ac8e4 JH |
3327 | #ifdef SUPPORT_CORK |
3328 | static BOOL corked = FALSE; | |
3329 | ||
3330 | if (more && !corked) gnutls_record_cork(state->session); | |
3331 | #endif | |
3332 | ||
3333 | DEBUG(D_tls) debug_printf("%s(%p, " SIZE_T_FMT "%s)\n", __FUNCTION__, | |
3334 | buff, left, more ? ", more" : ""); | |
059ec3d9 | 3335 | |
059ec3d9 PH |
3336 | while (left > 0) |
3337 | { | |
17c76198 PP |
3338 | DEBUG(D_tls) debug_printf("gnutls_record_send(SSL, %p, " SIZE_T_FMT ")\n", |
3339 | buff, left); | |
4896a319 AM |
3340 | |
3341 | do | |
3342 | outbytes = gnutls_record_send(state->session, buff, left); | |
3343 | while (outbytes == GNUTLS_E_AGAIN); | |
059ec3d9 | 3344 | |
17c76198 | 3345 | DEBUG(D_tls) debug_printf("outbytes=" SSIZE_T_FMT "\n", outbytes); |
059ec3d9 PH |
3346 | if (outbytes < 0) |
3347 | { | |
1b76ad22 | 3348 | DEBUG(D_tls) debug_printf("%s: gnutls_record_send err\n", __FUNCTION__); |
17c76198 | 3349 | record_io_error(state, outbytes, US"send", NULL); |
059ec3d9 PH |
3350 | return -1; |
3351 | } | |
3352 | if (outbytes == 0) | |
3353 | { | |
17c76198 | 3354 | record_io_error(state, 0, US"send", US"TLS channel closed on write"); |
059ec3d9 PH |
3355 | return -1; |
3356 | } | |
3357 | ||
3358 | left -= outbytes; | |
3359 | buff += outbytes; | |
3360 | } | |
3361 | ||
17c76198 PP |
3362 | if (len > INT_MAX) |
3363 | { | |
3364 | DEBUG(D_tls) | |
3365 | debug_printf("Whoops! Wrote more bytes (" SIZE_T_FMT ") than INT_MAX\n", | |
3366 | len); | |
3367 | len = INT_MAX; | |
3368 | } | |
3369 | ||
925ac8e4 JH |
3370 | #ifdef SUPPORT_CORK |
3371 | if (more != corked) | |
3372 | { | |
3373 | if (!more) (void) gnutls_record_uncork(state->session, 0); | |
3374 | corked = more; | |
3375 | } | |
3376 | #endif | |
3377 | ||
17c76198 | 3378 | return (int) len; |
059ec3d9 PH |
3379 | } |
3380 | ||
3381 | ||
3382 | ||
17c76198 | 3383 | |
059ec3d9 | 3384 | /************************************************* |
17c76198 | 3385 | * Random number generation * |
059ec3d9 PH |
3386 | *************************************************/ |
3387 | ||
17c76198 PP |
3388 | /* Pseudo-random number generation. The result is not expected to be |
3389 | cryptographically strong but not so weak that someone will shoot themselves | |
3390 | in the foot using it as a nonce in input in some email header scheme or | |
3391 | whatever weirdness they'll twist this into. The result should handle fork() | |
3392 | and avoid repeating sequences. OpenSSL handles that for us. | |
059ec3d9 | 3393 | |
17c76198 PP |
3394 | Arguments: |
3395 | max range maximum | |
3396 | Returns a random number in range [0, max-1] | |
059ec3d9 PH |
3397 | */ |
3398 | ||
af3498d6 | 3399 | #ifdef HAVE_GNUTLS_RND |
17c76198 PP |
3400 | int |
3401 | vaguely_random_number(int max) | |
059ec3d9 | 3402 | { |
17c76198 PP |
3403 | unsigned int r; |
3404 | int i, needed_len; | |
17c76198 PP |
3405 | uschar smallbuf[sizeof(r)]; |
3406 | ||
3407 | if (max <= 1) | |
3408 | return 0; | |
3409 | ||
3410 | needed_len = sizeof(r); | |
3411 | /* Don't take 8 times more entropy than needed if int is 8 octets and we were | |
d7978c0f JH |
3412 | asked for a number less than 10. */ |
3413 | ||
17c76198 PP |
3414 | for (r = max, i = 0; r; ++i) |
3415 | r >>= 1; | |
3416 | i = (i + 7) / 8; | |
3417 | if (i < needed_len) | |
3418 | needed_len = i; | |
3419 | ||
3420 | i = gnutls_rnd(GNUTLS_RND_NONCE, smallbuf, needed_len); | |
3421 | if (i < 0) | |
059ec3d9 | 3422 | { |
17c76198 PP |
3423 | DEBUG(D_all) debug_printf("gnutls_rnd() failed, using fallback.\n"); |
3424 | return vaguely_random_number_fallback(max); | |
3425 | } | |
3426 | r = 0; | |
d7978c0f JH |
3427 | for (uschar * p = smallbuf; needed_len; --needed_len, ++p) |
3428 | r = r * 256 + *p; | |
059ec3d9 | 3429 | |
17c76198 PP |
3430 | /* We don't particularly care about weighted results; if someone wants |
3431 | * smooth distribution and cares enough then they should submit a patch then. */ | |
3432 | return r % max; | |
059ec3d9 | 3433 | } |
af3498d6 PP |
3434 | #else /* HAVE_GNUTLS_RND */ |
3435 | int | |
3436 | vaguely_random_number(int max) | |
3437 | { | |
3438 | return vaguely_random_number_fallback(max); | |
3439 | } | |
3440 | #endif /* HAVE_GNUTLS_RND */ | |
059ec3d9 | 3441 | |
36f12725 NM |
3442 | |
3443 | ||
3444 | ||
3375e053 PP |
3445 | /************************************************* |
3446 | * Let tls_require_ciphers be checked at startup * | |
3447 | *************************************************/ | |
3448 | ||
3449 | /* The tls_require_ciphers option, if set, must be something which the | |
3450 | library can parse. | |
3451 | ||
3452 | Returns: NULL on success, or error message | |
3453 | */ | |
3454 | ||
3455 | uschar * | |
3456 | tls_validate_require_cipher(void) | |
3457 | { | |
3458 | int rc; | |
3459 | uschar *expciphers = NULL; | |
3460 | gnutls_priority_t priority_cache; | |
3461 | const char *errpos; | |
cf0c6164 | 3462 | uschar * dummy_errstr; |
3375e053 | 3463 | |
4d2a62a3 JH |
3464 | #ifdef GNUTLS_AUTO_GLOBAL_INIT |
3465 | # define validate_check_rc(Label) do { \ | |
3466 | if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) \ | |
3467 | return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0) | |
3468 | # define return_deinit(Label) do { return (Label); } while (0) | |
3469 | #else | |
3470 | # define validate_check_rc(Label) do { \ | |
3375e053 | 3471 | if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) gnutls_global_deinit(); \ |
4d2a62a3 JH |
3472 | return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0) |
3473 | # define return_deinit(Label) do { gnutls_global_deinit(); return (Label); } while (0) | |
3474 | #endif | |
3375e053 PP |
3475 | |
3476 | if (exim_gnutls_base_init_done) | |
3477 | log_write(0, LOG_MAIN|LOG_PANIC, | |
3478 | "already initialised GnuTLS, Exim developer bug"); | |
3479 | ||
9f707b89 | 3480 | #if defined(HAVE_GNUTLS_PKCS11) && !defined(GNUTLS_AUTO_PKCS11_MANUAL) |
2519e60d | 3481 | if (!gnutls_allow_auto_pkcs11) |
a5f239e4 PP |
3482 | { |
3483 | rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL); | |
3484 | validate_check_rc(US"gnutls_pkcs11_init"); | |
3485 | } | |
3486 | #endif | |
4d2a62a3 | 3487 | #ifndef GNUTLS_AUTO_GLOBAL_INIT |
3375e053 PP |
3488 | rc = gnutls_global_init(); |
3489 | validate_check_rc(US"gnutls_global_init()"); | |
4d2a62a3 | 3490 | #endif |
3375e053 PP |
3491 | exim_gnutls_base_init_done = TRUE; |
3492 | ||
3493 | if (!(tls_require_ciphers && *tls_require_ciphers)) | |
3494 | return_deinit(NULL); | |
3495 | ||
cf0c6164 JH |
3496 | if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers, |
3497 | &dummy_errstr)) | |
3375e053 PP |
3498 | return_deinit(US"failed to expand tls_require_ciphers"); |
3499 | ||
3500 | if (!(expciphers && *expciphers)) | |
3501 | return_deinit(NULL); | |
3502 | ||
3503 | DEBUG(D_tls) | |
3504 | debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers); | |
3505 | ||
3506 | rc = gnutls_priority_init(&priority_cache, CS expciphers, &errpos); | |
3507 | validate_check_rc(string_sprintf( | |
3508 | "gnutls_priority_init(%s) failed at offset %ld, \"%.8s..\"", | |
3509 | expciphers, errpos - CS expciphers, errpos)); | |
3510 | ||
3511 | #undef return_deinit | |
3512 | #undef validate_check_rc | |
4d2a62a3 | 3513 | #ifndef GNUTLS_AUTO_GLOBAL_INIT |
3375e053 | 3514 | gnutls_global_deinit(); |
4d2a62a3 | 3515 | #endif |
3375e053 PP |
3516 | |
3517 | return NULL; | |
3518 | } | |
3519 | ||
3520 | ||
3521 | ||
3522 | ||
36f12725 NM |
3523 | /************************************************* |
3524 | * Report the library versions. * | |
3525 | *************************************************/ | |
3526 | ||
3527 | /* See a description in tls-openssl.c for an explanation of why this exists. | |
3528 | ||
3529 | Arguments: a FILE* to print the results to | |
3530 | Returns: nothing | |
3531 | */ | |
3532 | ||
3533 | void | |
3534 | tls_version_report(FILE *f) | |
3535 | { | |
754a0503 PP |
3536 | fprintf(f, "Library version: GnuTLS: Compile: %s\n" |
3537 | " Runtime: %s\n", | |
3538 | LIBGNUTLS_VERSION, | |
3539 | gnutls_check_version(NULL)); | |
36f12725 NM |
3540 | } |
3541 | ||
b10c87b3 | 3542 | #endif /*!MACRO_PREDEF*/ |
2b4a568d JH |
3543 | /* vi: aw ai sw=2 |
3544 | */ | |
059ec3d9 | 3545 | /* End of tls-gnu.c */ |