1 /*
2 * ngIRCd -- The Next Generation IRC Daemon
3 * Copyright (c)2005-2008 Florian Westphal (fw@strlen.de).
4 * Copyright (c)2008-2014 Alexander Barton (alex@barton.de) and Contributors.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 * Please read the file COPYING, README and AUTHORS for more information.
11 */
12
13 #include "portab.h"
14
15 /**
16 * @file
17 * SSL wrapper functions
18 */
19
20 #include "conf-ssl.h"
21
22 #ifdef SSL_SUPPORT
23
24 #include "io.h"
25 #include <assert.h>
26 #include <stdio.h>
27 #include <string.h>
28 #include <stdlib.h>
29 #include <errno.h>
30
31 #define CONN_MODULE
32 #include "conn.h"
33 #include "conf.h"
34 #include "conn-func.h"
35 #include "conn-ssl.h"
36 #include "log.h"
37
38 #include "defines.h"
39
40 extern struct SSLOptions Conf_SSLOptions;
41
42 #ifdef HAVE_LIBSSL
43 #include <openssl/err.h>
44 #include <openssl/rand.h>
45 #include <openssl/dh.h>
46
47 static SSL_CTX * ssl_ctx;
48 static DH *dh_params;
49
50 static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c ));
51 #endif
52
53 #ifdef HAVE_LIBGNUTLS
54 #include <sys/types.h>
55 #include <sys/stat.h>
56 #include <fcntl.h>
57 #include <unistd.h>
58 #include <gnutls/x509.h>
59
60 #define DH_BITS 2048
61 #define DH_BITS_MIN 1024
62
63 #define MAX_HASH_SIZE 64 /* from gnutls-int.h */
64
65 typedef struct {
66 int refcnt;
67 gnutls_certificate_credentials_t x509_cred;
68 gnutls_dh_params_t dh_params;
69 } x509_cred_slot;
70
71 static array x509_creds = INIT_ARRAY;
72 static size_t x509_cred_idx;
73
74 static gnutls_dh_params_t dh_params;
75 static gnutls_priority_t priorities_cache = NULL;
76 static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void ));
77 #endif
78
79 #define SHA256_STRING_LEN (32 * 2 + 1)
80
81 static bool ConnSSL_Init_SSL PARAMS(( CONNECTION *c ));
82 static int ConnectAccept PARAMS(( CONNECTION *c, bool connect ));
83 static int ConnSSL_HandleError PARAMS(( CONNECTION *c, const int code, const char *fname ));
84
85 #ifdef HAVE_LIBGNUTLS
openreadclose(const char * name,size_t * len)86 static char * openreadclose(const char *name, size_t *len)
87 {
88 char *buf = NULL;
89 struct stat s;
90 ssize_t br;
91 int fd = open(name, O_RDONLY);
92 if (fd < 0) {
93 Log(LOG_ERR, "Could not open %s: %s", name, strerror(errno));
94 return NULL;
95 }
96 if (fstat(fd, &s)) {
97 Log(LOG_ERR, "Could not fstat %s: %s", name, strerror(errno));
98 goto out;
99 }
100 if (!S_ISREG(s.st_mode)) {
101 Log(LOG_ERR, "%s: Not a regular file", name);
102 goto out;
103 }
104 if (s.st_size <= 0) {
105 Log(LOG_ERR, "%s: invalid file length (size %ld <= 0)", name, (long) s.st_size);
106 goto out;
107 }
108 buf = malloc(s.st_size);
109 if (!buf) {
110 Log(LOG_ERR, "Could not malloc %lu bytes for file %s: %s", s.st_size, name, strerror(errno));
111 goto out;
112 }
113 br = read(fd, buf, s.st_size);
114 if (br != (ssize_t)s.st_size) {
115 Log(LOG_ERR, "Could not read file %s: read returned %ld, expected %ld: %s",
116 name, (long) br, (long) s.st_size, br == -1 ? strerror(errno):"short read?!");
117 memset(buf, 0, s.st_size);
118 free(buf);
119 buf = NULL;
120 } else {
121 *len = br;
122 }
123 out:
124 close(fd);
125 return buf;
126 }
127 #endif
128
129
130 #ifdef HAVE_LIBSSL
131 /**
132 * Log OpenSSL error message.
133 *
134 * @param msg The error message.
135 * @param info Additional information text or NULL.
136 */
137 static void
LogOpenSSLError(const char * error,const char * info)138 LogOpenSSLError(const char *error, const char *info)
139 {
140 unsigned long err = ERR_get_error();
141 char * errmsg = err
142 ? ERR_error_string(err, NULL)
143 : "Unable to determine error";
144
145 assert(error != NULL);
146
147 if (info)
148 Log(LOG_ERR, "%s: %s (%s)", error, info, errmsg);
149 else
150 Log(LOG_ERR, "%s: %s", error, errmsg);
151 }
152
153
154 static int
pem_passwd_cb(char * buf,int size,int rwflag,void * password)155 pem_passwd_cb(char *buf, int size, int rwflag, void *password)
156 {
157 array *pass = password;
158 int passlen;
159
160 (void)rwflag; /* rwflag is unused if DEBUG is not set. */
161 assert(rwflag == 0); /* 0 -> callback used for decryption.
162 * See SSL_CTX_set_default_passwd_cb(3) */
163
164 passlen = (int) array_bytes(pass);
165
166 LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen);
167 assert(passlen >= 0);
168 if (passlen <= 0) {
169 Log(LOG_ERR, "PEM password required but not set [in pem_passwd_cb()]!");
170 return 0;
171 }
172 size = passlen > size ? size : passlen;
173 memcpy(buf, (char *)(array_start(pass)), size);
174 return size;
175 }
176
177
178 static int
Verify_openssl(UNUSED int preverify_ok,UNUSED X509_STORE_CTX * x509_ctx)179 Verify_openssl(UNUSED int preverify_ok, UNUSED X509_STORE_CTX *x509_ctx)
180 {
181 return 1;
182 }
183 #endif
184
185
186 static bool
Load_DH_params(void)187 Load_DH_params(void)
188 {
189 #ifdef HAVE_LIBSSL
190 FILE *fp;
191 bool ret = true;
192
193 if (!Conf_SSLOptions.DHFile) {
194 Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!");
195 return false;
196 }
197 fp = fopen(Conf_SSLOptions.DHFile, "r");
198 if (!fp) {
199 Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno));
200 return false;
201 }
202 dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL);
203 if (!dh_params) {
204 Log(LOG_ERR, "%s: Failed to read SSL DH parameters!",
205 Conf_SSLOptions.DHFile);
206 ret = false;
207 }
208 fclose(fp);
209 return ret;
210 #endif
211 #ifdef HAVE_LIBGNUTLS
212 bool need_dhgenerate = true;
213 int err;
214 gnutls_dh_params_t tmp_dh_params;
215
216 err = gnutls_dh_params_init(&tmp_dh_params);
217 if (err < 0) {
218 Log(LOG_ERR, "Failed to initialize SSL DH parameters: %s",
219 gnutls_strerror(err));
220 return false;
221 }
222 if (Conf_SSLOptions.DHFile) {
223 gnutls_datum_t dhparms;
224 size_t size;
225 dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size);
226 if (dhparms.data) {
227 dhparms.size = size;
228 err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
229 if (err == 0)
230 need_dhgenerate = false;
231 else
232 Log(LOG_ERR,
233 "Failed to initialize SSL DH parameters: %s",
234 gnutls_strerror(err));
235
236 memset(dhparms.data, 0, size);
237 free(dhparms.data);
238 }
239 }
240 if (need_dhgenerate) {
241 Log(LOG_WARNING,
242 "DHFile not set, generating %u bit DH parameters. This may take a while ...",
243 DH_BITS);
244 err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS);
245 if (err < 0) {
246 Log(LOG_ERR, "Failed to generate SSL DH parameters: %s",
247 gnutls_strerror(err));
248 return false;
249 }
250 }
251 dh_params = tmp_dh_params;
252 return true;
253 #endif
254 }
255
256
ConnSSL_Free(CONNECTION * c)257 void ConnSSL_Free(CONNECTION *c)
258 {
259 #ifdef HAVE_LIBSSL
260 SSL *ssl = c->ssl_state.ssl;
261 if (ssl) {
262 SSL_shutdown(ssl);
263 SSL_free(ssl);
264 c->ssl_state.ssl = NULL;
265 if (c->ssl_state.fingerprint) {
266 free(c->ssl_state.fingerprint);
267 c->ssl_state.fingerprint = NULL;
268 }
269 }
270 #endif
271 #ifdef HAVE_LIBGNUTLS
272 gnutls_session_t sess = c->ssl_state.gnutls_session;
273 if (Conn_OPTION_ISSET(c, CONN_SSL)) {
274 gnutls_bye(sess, GNUTLS_SHUT_RDWR);
275 gnutls_deinit(sess);
276 }
277 x509_cred_slot *slot = array_get(&x509_creds, sizeof(x509_cred_slot), c->ssl_state.x509_cred_idx);
278 assert(slot != NULL);
279 assert(slot->refcnt > 0);
280 assert(slot->x509_cred != NULL);
281 slot->refcnt--;
282 if ((c->ssl_state.x509_cred_idx != x509_cred_idx) && (slot->refcnt <= 0)) {
283 Log(LOG_INFO, "Discarding X509 certificate credentials from slot %zd.",
284 c->ssl_state.x509_cred_idx);
285 gnutls_certificate_free_keys(slot->x509_cred);
286 gnutls_certificate_free_credentials(slot->x509_cred);
287 slot->x509_cred = NULL;
288 gnutls_dh_params_deinit(slot->dh_params);
289 slot->dh_params = NULL;
290 slot->refcnt = 0;
291 }
292 #endif
293 assert(Conn_OPTION_ISSET(c, CONN_SSL));
294 /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */
295 Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL);
296 }
297
298
299 bool
ConnSSL_InitLibrary(void)300 ConnSSL_InitLibrary( void )
301 {
302 if (!Conf_SSLInUse()) {
303 LogDebug("SSL not in use, skipping initialization.");
304 return true;
305 }
306
307 #ifdef HAVE_LIBSSL
308 SSL_CTX *newctx;
309
310 #if OPENSSL_API_COMPAT < 0x10100000L
311 if (!ssl_ctx) {
312 SSL_library_init();
313 SSL_load_error_strings();
314 }
315 #endif
316
317 if (!RAND_status()) {
318 Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
319 /*
320 * it is probably best to fail and let the user install EGD or
321 * a similar program if no kernel random device is available.
322 * According to OpenSSL RAND_egd(3): "The automatic query of
323 * /var/run/egd-pool et al was added in OpenSSL 0.9.7";
324 * so it makes little sense to deal with PRNGD seeding ourselves.
325 */
326 array_free(&Conf_SSLOptions.ListenPorts);
327 return false;
328 }
329
330 newctx = SSL_CTX_new(SSLv23_method());
331 if (!newctx) {
332 LogOpenSSLError("Failed to create SSL context", NULL);
333 array_free(&Conf_SSLOptions.ListenPorts);
334 return false;
335 }
336
337 if (!ConnSSL_LoadServerKey_openssl(newctx)) {
338 /* Failed to read new key but an old ssl context
339 * already exists -> reuse old context */
340 if (ssl_ctx) {
341 SSL_CTX_free(newctx);
342 Log(LOG_WARNING,
343 "Re-Initializing of SSL failed, using old keys!");
344 return true;
345 }
346 /* No preexisting old context -> error. */
347 goto out;
348 }
349
350 if (SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0) {
351 Log(LOG_ERR, "Failed to apply OpenSSL cipher list \"%s\"!",
352 Conf_SSLOptions.CipherList);
353 goto out;
354 }
355
356 SSL_CTX_set_session_id_context(newctx, (unsigned char *)"ngircd", 6);
357 SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
358 SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
359 SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
360 Verify_openssl);
361 SSL_CTX_free(ssl_ctx);
362 ssl_ctx = newctx;
363 Log(LOG_INFO, "%s initialized.", OpenSSL_version(OPENSSL_VERSION));
364 return true;
365 out:
366 SSL_CTX_free(newctx);
367 array_free(&Conf_SSLOptions.ListenPorts);
368 return false;
369 #endif
370 #ifdef HAVE_LIBGNUTLS
371 int err;
372 static bool initialized;
373
374 if (!initialized) {
375 err = gnutls_global_init();
376 if (err) {
377 Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
378 gnutls_strerror(err));
379 goto out;
380 }
381 }
382
383 if (!ConnSSL_LoadServerKey_gnutls())
384 goto out;
385
386 if (priorities_cache != NULL) {
387 gnutls_priority_deinit(priorities_cache);
388 }
389 if (gnutls_priority_init(&priorities_cache, Conf_SSLOptions.CipherList,
390 NULL) != GNUTLS_E_SUCCESS) {
391 Log(LOG_ERR,
392 "Failed to apply GnuTLS cipher list \"%s\"!",
393 Conf_SSLOptions.CipherList);
394 goto out;
395 }
396
397 Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
398 initialized = true;
399 return true;
400 out:
401 array_free(&Conf_SSLOptions.ListenPorts);
402 return false;
403 #endif
404 }
405
406
407 #ifdef HAVE_LIBGNUTLS
408 static bool
ConnSSL_LoadServerKey_gnutls(void)409 ConnSSL_LoadServerKey_gnutls(void)
410 {
411 int err;
412 const char *cert_file;
413
414 x509_cred_slot *slot = NULL;
415 gnutls_certificate_credentials_t x509_cred;
416
417 err = gnutls_certificate_allocate_credentials(&x509_cred);
418 if (err < 0) {
419 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
420 gnutls_strerror(err));
421 return false;
422 }
423
424 cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
425 if (!cert_file) {
426 Log(LOG_ERR, "No SSL server key configured!");
427 return false;
428 }
429
430 if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
431 Log(LOG_WARNING,
432 "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
433
434 if (!Load_DH_params())
435 return false;
436
437 gnutls_certificate_set_dh_params(x509_cred, dh_params);
438 err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
439 if (err < 0) {
440 Log(LOG_ERR,
441 "Failed to set certificate key file (cert %s, key %s): %s",
442 cert_file,
443 Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
444 gnutls_strerror(err));
445 return false;
446 }
447
448 /* Free currently active x509 context (if any) unless it is still in use */
449 slot = array_get(&x509_creds, sizeof(x509_cred_slot), x509_cred_idx);
450 if ((slot != NULL) && (slot->refcnt <= 0) && (slot->x509_cred != NULL)) {
451 Log(LOG_INFO, "Discarding X509 certificate credentials from slot %zd.", x509_cred_idx);
452 gnutls_certificate_free_keys(slot->x509_cred);
453 gnutls_certificate_free_credentials(slot->x509_cred);
454 slot->x509_cred = NULL;
455 gnutls_dh_params_deinit(slot->dh_params);
456 slot->dh_params = NULL;
457 slot->refcnt = 0;
458 }
459
460 /* Find free slot */
461 x509_cred_idx = (size_t) -1;
462 size_t i;
463 for (slot = array_start(&x509_creds), i = 0;
464 i < array_length(&x509_creds, sizeof(x509_cred_slot));
465 slot++, i++) {
466 if (slot->refcnt <= 0) {
467 x509_cred_idx = i;
468 break;
469 }
470 }
471 /* ... allocate new slot otherwise. */
472 if (x509_cred_idx == (size_t) -1) {
473 x509_cred_idx = array_length(&x509_creds, sizeof(x509_cred_slot));
474 slot = array_alloc(&x509_creds, sizeof(x509_cred_slot), x509_cred_idx);
475 if (slot == NULL) {
476 Log(LOG_ERR, "Failed to allocate new slot for certificate credentials");
477 return false;
478 }
479 }
480 Log(LOG_INFO, "Storing new X509 certificate credentials in slot %zd.", x509_cred_idx);
481 slot->x509_cred = x509_cred;
482 slot->refcnt = 0;
483
484 return true;
485 }
486 #endif
487
488
489 #ifdef HAVE_LIBSSL
490 static bool
ConnSSL_LoadServerKey_openssl(SSL_CTX * ctx)491 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
492 {
493 char *cert_key;
494
495 assert(ctx);
496 if (!Conf_SSLOptions.KeyFile) {
497 Log(LOG_ERR, "No SSL server key configured!");
498 return false;
499 }
500
501 SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
502 SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
503
504 if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
505 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
506 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
507 return false;
508 }
509
510 cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
511 if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
512 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
513 LogOpenSSLError("Failed to load certificate chain", cert_key);
514 return false;
515 }
516
517 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
518
519 if (!SSL_CTX_check_private_key(ctx)) {
520 LogOpenSSLError("Server private key does not match certificate", NULL);
521 return false;
522 }
523 if (Load_DH_params()) {
524 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
525 LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
526 /* don't return false here: the non-DH modes will still work */
527 DH_free(dh_params);
528 dh_params = NULL;
529 }
530 return true;
531 }
532
533
534 #endif
535 static bool
ConnSSL_Init_SSL(CONNECTION * c)536 ConnSSL_Init_SSL(CONNECTION *c)
537 {
538 int ret;
539
540 LogDebug("Initializing SSL ...");
541 assert(c != NULL);
542
543 #ifdef HAVE_LIBSSL
544 if (!ssl_ctx) {
545 Log(LOG_ERR,
546 "Can't initialize SSL context, OpenSSL initialization failed at startup!");
547 return false;
548 }
549 assert(c->ssl_state.ssl == NULL);
550 assert(c->ssl_state.fingerprint == NULL);
551
552 c->ssl_state.ssl = SSL_new(ssl_ctx);
553 if (!c->ssl_state.ssl) {
554 LogOpenSSLError("Failed to create SSL structure", NULL);
555 return false;
556 }
557 Conn_OPTION_ADD(c, CONN_SSL);
558
559 ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
560 if (ret != 1) {
561 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
562 ConnSSL_Free(c);
563 return false;
564 }
565 #endif
566 #ifdef HAVE_LIBGNUTLS
567 Conn_OPTION_ADD(c, CONN_SSL);
568 ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
569 if (ret != GNUTLS_E_SUCCESS) {
570 Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
571 gnutls_strerror(ret));
572 ConnSSL_Free(c);
573 return false;
574 }
575 /*
576 * The intermediate (long) cast is here to avoid a warning like:
577 * "cast to pointer from integer of different size" on 64-bit platforms.
578 * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
579 * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
580 */
581 gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
582 (gnutls_transport_ptr_t) (long) c->sock);
583 gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
584 GNUTLS_CERT_REQUEST);
585
586 Log(LOG_INFO, "Using X509 credentials from slot %zd", x509_cred_idx);
587 c->ssl_state.x509_cred_idx = x509_cred_idx;
588 x509_cred_slot *slot = array_get(&x509_creds, sizeof(x509_cred_slot), x509_cred_idx);
589 slot->refcnt++;
590 ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
591 GNUTLS_CRD_CERTIFICATE, slot->x509_cred);
592 if (ret != 0) {
593 Log(LOG_ERR, "Failed to set SSL credentials: %s",
594 gnutls_strerror(ret));
595 ConnSSL_Free(c);
596 return false;
597 }
598 gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
599 #endif
600 return true;
601 }
602
603
604 bool
ConnSSL_PrepareConnect(CONNECTION * c,UNUSED CONF_SERVER * s)605 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
606 {
607 bool ret;
608 #ifdef HAVE_LIBGNUTLS
609 int err;
610
611 err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
612 if (err) {
613 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
614 gnutls_strerror(err));
615 return false;
616 }
617 #endif
618 ret = ConnSSL_Init_SSL(c);
619 if (!ret)
620 return false;
621 Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
622 #ifdef HAVE_LIBSSL
623 assert(c->ssl_state.ssl);
624 SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
625 #endif
626 return true;
627 }
628
629
630 /**
631 * Check and handle error return codes after failed calls to SSL functions.
632 *
633 * OpenSSL:
634 * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
635 * SSL_write() on ssl.
636 *
637 * GnuTLS:
638 * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
639 *
640 * @param c The connection handle.
641 * @prarm code The return code.
642 * @param fname The name of the function in which the error occurred.
643 * @return -1 on fatal errors, 0 if we can try again later.
644 */
645 static int
ConnSSL_HandleError(CONNECTION * c,const int code,const char * fname)646 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
647 {
648 #ifdef HAVE_LIBSSL
649 int ret = SSL_ERROR_SYSCALL;
650 unsigned long sslerr;
651 int real_errno = errno;
652
653 ret = SSL_get_error(c->ssl_state.ssl, code);
654
655 switch (ret) {
656 case SSL_ERROR_WANT_READ:
657 io_event_del(c->sock, IO_WANTWRITE);
658 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
659 return 0; /* try again later */
660 case SSL_ERROR_WANT_WRITE:
661 io_event_del(c->sock, IO_WANTREAD);
662 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
663 case SSL_ERROR_NONE:
664 return 0; /* try again later */
665 case SSL_ERROR_ZERO_RETURN:
666 LogDebug("SSL connection shut down normally.");
667 break;
668 case SSL_ERROR_SYSCALL:
669 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
670 * and SSL_ERROR_WANT_X509_LOOKUP */
671 sslerr = ERR_get_error();
672 if (sslerr) {
673 Log(LOG_ERR, "SSL error: %s [in %s()]!",
674 ERR_error_string(sslerr, NULL), fname);
675 } else {
676 switch (code) { /* EOF that violated protocol */
677 case 0:
678 Log(LOG_ERR,
679 "SSL error, client disconnected [in %s()]!",
680 fname);
681 break;
682 case -1: /* low level socket I/O error, check errno */
683 Log(LOG_ERR, "SSL error: %s [in %s()]!",
684 strerror(real_errno), fname);
685 }
686 }
687 break;
688 case SSL_ERROR_SSL:
689 LogOpenSSLError("SSL protocol error", fname);
690 break;
691 default:
692 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
693 }
694 ConnSSL_Free(c);
695 return -1;
696 #endif
697 #ifdef HAVE_LIBGNUTLS
698 switch (code) {
699 case GNUTLS_E_AGAIN:
700 case GNUTLS_E_INTERRUPTED:
701 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
702 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
703 io_event_del(c->sock, IO_WANTREAD);
704 } else {
705 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
706 io_event_del(c->sock, IO_WANTWRITE);
707 }
708 break;
709 default:
710 assert(code < 0);
711 if (gnutls_error_is_fatal(code)) {
712 Log(LOG_ERR, "SSL error: %s [%s].",
713 gnutls_strerror(code), fname);
714 ConnSSL_Free(c);
715 return -1;
716 }
717 }
718 return 0;
719 #endif
720 }
721
722
723 static void
ConnSSL_LogCertInfo(CONNECTION * c)724 ConnSSL_LogCertInfo( CONNECTION *c )
725 {
726 #ifdef HAVE_LIBSSL
727 SSL *ssl = c->ssl_state.ssl;
728
729 assert(ssl);
730
731 Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
732 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
733 #endif
734 #ifdef HAVE_LIBGNUTLS
735 gnutls_session_t sess = c->ssl_state.gnutls_session;
736 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
737
738 Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
739 c->sock,
740 gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
741 gnutls_cipher_get_name(cipher),
742 gnutls_mac_get_name(gnutls_mac_get(sess)));
743 #endif
744 }
745
746
747 /*
748 Accept incoming SSL connection.
749 Return Values:
750 1: SSL Connection established
751 0: try again
752 -1: SSL Connection not established due to fatal error.
753 */
754 int
ConnSSL_Accept(CONNECTION * c)755 ConnSSL_Accept( CONNECTION *c )
756 {
757 assert(c != NULL);
758 if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
759 #ifdef HAVE_LIBGNUTLS
760 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
761 if (err) {
762 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
763 gnutls_strerror(err));
764 return false;
765 }
766 #endif
767 if (!ConnSSL_Init_SSL(c))
768 return -1;
769 }
770 return ConnectAccept(c, false );
771 }
772
773
774 int
ConnSSL_Connect(CONNECTION * c)775 ConnSSL_Connect( CONNECTION *c )
776 {
777 assert(c != NULL);
778 #ifdef HAVE_LIBSSL
779 assert(c->ssl_state.ssl);
780 #endif
781 assert(Conn_OPTION_ISSET(c, CONN_SSL));
782 return ConnectAccept(c, true);
783 }
784
785 static int
ConnSSL_InitCertFp(CONNECTION * c)786 ConnSSL_InitCertFp( CONNECTION *c )
787 {
788 const char hex[] = "0123456789abcdef";
789 int i;
790
791 #ifdef HAVE_LIBSSL
792 unsigned char digest[EVP_MAX_MD_SIZE];
793 unsigned int digest_size;
794 X509 *cert;
795
796 cert = SSL_get_peer_certificate(c->ssl_state.ssl);
797 if (!cert)
798 return 0;
799
800 if (!X509_digest(cert, EVP_sha256(), digest, &digest_size)) {
801 X509_free(cert);
802 return 0;
803 }
804
805 X509_free(cert);
806 #endif /* HAVE_LIBSSL */
807 #ifdef HAVE_LIBGNUTLS
808 gnutls_x509_crt_t cert;
809 unsigned int cert_list_size;
810 const gnutls_datum_t *cert_list;
811 unsigned char digest[MAX_HASH_SIZE];
812 size_t digest_size;
813
814 if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) !=
815 GNUTLS_CRT_X509)
816 return 0;
817
818 if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
819 return 0;
820
821 cert_list_size = 0;
822 cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
823 &cert_list_size);
824 if (!cert_list) {
825 gnutls_x509_crt_deinit(cert);
826 return 0;
827 }
828
829 if (gnutls_x509_crt_import(cert, &cert_list[0],
830 GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
831 gnutls_x509_crt_deinit(cert);
832 return 0;
833 }
834
835 digest_size = sizeof(digest);
836 if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA256, digest,
837 &digest_size)) {
838 gnutls_x509_crt_deinit(cert);
839 return 0;
840 }
841
842 gnutls_x509_crt_deinit(cert);
843 #endif /* HAVE_LIBGNUTLS */
844
845 assert(c->ssl_state.fingerprint == NULL);
846
847 c->ssl_state.fingerprint = malloc(SHA256_STRING_LEN);
848 if (!c->ssl_state.fingerprint)
849 return 0;
850
851 for (i = 0; i < (int)digest_size; i++) {
852 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
853 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
854 }
855 c->ssl_state.fingerprint[i * 2] = '\0';
856
857 return 1;
858 }
859
860 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
861 static int
ConnectAccept(CONNECTION * c,bool connect)862 ConnectAccept( CONNECTION *c, bool connect)
863 {
864 int ret;
865 #ifdef HAVE_LIBSSL
866 SSL *ssl = c->ssl_state.ssl;
867 assert(ssl != NULL);
868
869 ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
870 if (1 != ret)
871 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
872 #endif
873 #ifdef HAVE_LIBGNUTLS
874 (void) connect;
875 ret = gnutls_handshake(c->ssl_state.gnutls_session);
876 if (ret)
877 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
878 #endif /* _GNUTLS */
879 (void)ConnSSL_InitCertFp(c);
880
881 Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
882 ConnSSL_LogCertInfo(c);
883
884 Conn_StartLogin(CONNECTION2ID(c));
885 return 1;
886 }
887
888
889 ssize_t
ConnSSL_Write(CONNECTION * c,const void * buf,size_t count)890 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
891 {
892 ssize_t bw;
893
894 Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
895
896 assert(count > 0);
897 #ifdef HAVE_LIBSSL
898 bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
899 #endif
900 #ifdef HAVE_LIBGNUTLS
901 bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
902 #endif
903 if (bw > 0)
904 return bw;
905 if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
906 errno = EAGAIN; /* try again */
907 return -1;
908 }
909
910
911 ssize_t
ConnSSL_Read(CONNECTION * c,void * buf,size_t count)912 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
913 {
914 ssize_t br;
915
916 Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
917 #ifdef HAVE_LIBSSL
918 br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
919 if (br > 0) /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
920 return br;
921 #endif
922 #ifdef HAVE_LIBGNUTLS
923 br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
924 if (br >= 0) /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
925 return br;
926 #endif
927 /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
928 if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
929 errno = EAGAIN;
930 return -1;
931 }
932 return 0;
933 }
934
935
936 bool
ConnSSL_GetCipherInfo(CONNECTION * c,char * buf,size_t len)937 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
938 {
939 #ifdef HAVE_LIBSSL
940 char *nl;
941 SSL *ssl = c->ssl_state.ssl;
942
943 if (!ssl)
944 return false;
945 *buf = 0;
946 SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
947 nl = strchr(buf, '\n');
948 if (nl)
949 *nl = 0;
950 return true;
951 #endif
952 #ifdef HAVE_LIBGNUTLS
953 if (Conn_OPTION_ISSET(c, CONN_SSL)) {
954 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
955 unsigned keysize;
956
957 gnutls_session_t sess = c->ssl_state.gnutls_session;
958 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
959 name_cipher = gnutls_cipher_get_name(cipher);
960 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
961 keysize = gnutls_cipher_get_key_size(cipher) * 8;
962 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
963 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
964
965 return snprintf(buf, len, "%s-%s%15s Kx=%s Enc=%s(%u) Mac=%s",
966 name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
967 }
968 return false;
969 #endif
970 }
971
972 char *
ConnSSL_GetCertFp(CONNECTION * c)973 ConnSSL_GetCertFp(CONNECTION *c)
974 {
975 return c->ssl_state.fingerprint;
976 }
977
978 bool
ConnSSL_SetCertFp(CONNECTION * c,const char * fingerprint)979 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
980 {
981 assert (c != NULL);
982 c->ssl_state.fingerprint = strndup(fingerprint, SHA256_STRING_LEN - 1);
983 return c->ssl_state.fingerprint != NULL;
984 }
985 #else
986
987 bool
ConnSSL_InitLibrary(void)988 ConnSSL_InitLibrary(void)
989 {
990 return true;
991 }
992
993 #endif /* SSL_SUPPORT */
994 /* -eof- */
995