summaryrefslogtreecommitdiff
path: root/src/modules/extra/m_ssl_gnutls.cpp
blob: 9f21d6d281397d2fb235a1caf43a1f724d3b4fa9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
/*
 * InspIRCd -- Internet Relay Chat Daemon
 *
 *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
 *   Copyright (C) 2008 John Brooks <john.brooks@dereferenced.net>
 *   Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
 *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
 *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
 *
 * This file is part of InspIRCd.  InspIRCd is free software: you can
 * redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation, version 2.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */


#include "inspircd.h"
#include <gcrypt.h>
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#include "modules/ssl.h"
#include "modules/cap.h"

#if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 9) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 9 && GNUTLS_VERSION_PATCH >= 8))
#define GNUTLS_HAS_MAC_GET_ID
#include <gnutls/crypto.h>
#endif

#ifdef _WIN32
# pragma comment(lib, "libgnutls.lib")
# pragma comment(lib, "libgcrypt.lib")
# pragma comment(lib, "libgpg-error.lib")
# pragma comment(lib, "user32.lib")
# pragma comment(lib, "advapi32.lib")
# pragma comment(lib, "libgcc.lib")
# pragma comment(lib, "libmingwex.lib")
# pragma comment(lib, "gdi32.lib")
#endif

/* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") exec("libgcrypt-config --cflags") -Wno-pedantic */
/* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") exec("libgcrypt-config --libs") */

#ifndef GNUTLS_VERSION_MAJOR
#define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
#define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
#define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
#endif

// These don't exist in older GnuTLS versions
#if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 1) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 1 && GNUTLS_VERSION_PATCH >= 7))
#define GNUTLS_NEW_PRIO_API
#endif

#if(GNUTLS_VERSION_MAJOR < 2)
typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
typedef gnutls_dh_params_t gnutls_dh_params;
#endif

enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };

static std::vector<gnutls_x509_crt_t> x509_certs;
static gnutls_x509_privkey_t x509_key;
#if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
	const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {

	st->type = GNUTLS_CRT_X509;
#else
static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
	const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr2_st * st) {
	st->cert_type = GNUTLS_CRT_X509;
	st->key_type = GNUTLS_PRIVKEY_X509;
#endif
	st->ncerts = x509_certs.size();
	st->cert.x509 = &x509_certs[0];
	st->key.x509 = x509_key;
	st->deinit_all = 0;

	return 0;
}

class RandGen : public HandlerBase2<void, char*, size_t>
{
 public:
	RandGen() {}
	void Call(char* buffer, size_t len)
	{
		gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
	}
};

/** Represents an SSL user's extra data
 */
class issl_session
{
public:
	StreamSocket* socket;
	gnutls_session_t sess;
	issl_status status;
	reference<ssl_cert> cert;

	issl_session() : socket(NULL), sess(NULL) {}
};

class GnuTLSIOHook : public SSLIOHook
{
 private:
	void InitSession(StreamSocket* user, bool me_server)
	{
		issl_session* session = &sessions[user->GetFd()];

		gnutls_init(&session->sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
		session->socket = user;

		#ifdef GNUTLS_NEW_PRIO_API
		gnutls_priority_set(session->sess, priority);
		#else
		gnutls_set_default_priority(session->sess);
		#endif
		gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
		gnutls_dh_set_prime_bits(session->sess, dh_bits);
		gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(session));
		gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
		gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);

		if (me_server)
			gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.

		Handshake(session, user);
	}

	void CloseSession(issl_session* session)
	{
		if (session->sess)
		{
			gnutls_bye(session->sess, GNUTLS_SHUT_WR);
			gnutls_deinit(session->sess);
		}
		session->socket = NULL;
		session->sess = NULL;
		session->cert = NULL;
		session->status = ISSL_NONE;
	}

	bool Handshake(issl_session* session, StreamSocket* user)
	{
		int ret = gnutls_handshake(session->sess);

		if (ret < 0)
		{
			if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
			{
				// Handshake needs resuming later, read() or write() would have blocked.

				if(gnutls_record_get_direction(session->sess) == 0)
				{
					// gnutls_handshake() wants to read() again.
					session->status = ISSL_HANDSHAKING_READ;
					ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
				}
				else
				{
					// gnutls_handshake() wants to write() again.
					session->status = ISSL_HANDSHAKING_WRITE;
					ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
				}
			}
			else
			{
				user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
				CloseSession(session);
				session->status = ISSL_CLOSING;
			}

			return false;
		}
		else
		{
			// Change the seesion state
			session->status = ISSL_HANDSHAKEN;

			VerifyCertificate(session,user);

			// Finish writing, if any left
			ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);

			return true;
		}
	}

	void VerifyCertificate(issl_session* session, StreamSocket* user)
	{
		if (!session->sess || !user)
			return;

		unsigned int status;
		const gnutls_datum_t* cert_list;
		int ret;
		unsigned int cert_list_size;
		gnutls_x509_crt_t cert;
		char str[512];
		unsigned char digest[512];
		size_t digest_size = sizeof(digest);
		size_t name_size = sizeof(str);
		ssl_cert* certinfo = new ssl_cert;
		session->cert = certinfo;

		/* This verification function uses the trusted CAs in the credentials
		 * structure. So you must have installed one or more CA certificates.
		 */
		ret = gnutls_certificate_verify_peers2(session->sess, &status);

		if (ret < 0)
		{
			certinfo->error = std::string(gnutls_strerror(ret));
			return;
		}

		certinfo->invalid = (status & GNUTLS_CERT_INVALID);
		certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
		certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
		certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);

		/* Up to here the process is the same for X.509 certificates and
		 * OpenPGP keys. From now on X.509 certificates are assumed. This can
		 * be easily extended to work with openpgp keys as well.
		 */
		if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
		{
			certinfo->error = "No X509 keys sent";
			return;
		}

		ret = gnutls_x509_crt_init(&cert);
		if (ret < 0)
		{
			certinfo->error = gnutls_strerror(ret);
			return;
		}

		cert_list_size = 0;
		cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
		if (cert_list == NULL)
		{
			certinfo->error = "No certificate was found";
			goto info_done_dealloc;
		}

		/* This is not a real world example, since we only check the first
		 * certificate in the given chain.
		 */

		ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
		if (ret < 0)
		{
			certinfo->error = gnutls_strerror(ret);
			goto info_done_dealloc;
		}

		gnutls_x509_crt_get_dn(cert, str, &name_size);
		certinfo->dn = str;

		gnutls_x509_crt_get_issuer_dn(cert, str, &name_size);
		certinfo->issuer = str;

		if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
		{
			certinfo->error = gnutls_strerror(ret);
		}
		else
		{
			certinfo->fingerprint = BinToHex(digest, digest_size);
		}

		/* Beware here we do not check for errors.
		 */
		if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
		{
			certinfo->error = "Not activated, or expired certificate";
		}

info_done_dealloc:
		gnutls_x509_crt_deinit(cert);
	}

	static const char* UnknownIfNULL(const char* str)
	{
		return str ? str : "UNKNOWN";
	}

	static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
	{
		issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
		if (session->socket->GetEventMask() & FD_READ_WILL_BLOCK)
		{
#ifdef _WIN32
			gnutls_transport_set_errno(session->sess, EAGAIN);
#else
			errno = EAGAIN;
#endif
			return -1;
		}

		int rv = ServerInstance->SE->Recv(session->socket, reinterpret_cast<char *>(buffer), size, 0);

#ifdef _WIN32
		if (rv < 0)
		{
			/* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
			 * and then set errno appropriately.
			 * The gnutls library may also have a different errno variable than us, see
			 * gnutls_transport_set_errno(3).
			 */
			gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
		}
#endif

		if (rv < (int)size)
			ServerInstance->SE->ChangeEventMask(session->socket, FD_READ_WILL_BLOCK);
		return rv;
	}

	static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
	{
		issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
		if (session->socket->GetEventMask() & FD_WRITE_WILL_BLOCK)
		{
#ifdef _WIN32
			gnutls_transport_set_errno(session->sess, EAGAIN);
#else
			errno = EAGAIN;
#endif
			return -1;
		}

		int rv = ServerInstance->SE->Send(session->socket, reinterpret_cast<const char *>(buffer), size, 0);

#ifdef _WIN32
		if (rv < 0)
		{
			/* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
			 * and then set errno appropriately.
			 * The gnutls library may also have a different errno variable than us, see
			 * gnutls_transport_set_errno(3).
			 */
			gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
		}
#endif

		if (rv < (int)size)
			ServerInstance->SE->ChangeEventMask(session->socket, FD_WRITE_WILL_BLOCK);
		return rv;
	}

 public:
 	issl_session* sessions;
	gnutls_certificate_credentials_t x509_cred;

	gnutls_digest_algorithm_t hash;
	#ifdef GNUTLS_NEW_PRIO_API
	gnutls_priority_t priority;
	#endif
	int dh_bits;

	GnuTLSIOHook(Module* parent)
		: SSLIOHook(parent, "ssl/gnutls")
	{
		sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
	}

	~GnuTLSIOHook()
	{
		delete[] sessions;
	}

	void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
	{
		issl_session* session = &sessions[user->GetFd()];

		/* For STARTTLS: Don't try and init a session on a socket that already has a session */
		if (session->sess)
			return;

		InitSession(user, true);
	}

	void OnStreamSocketConnect(StreamSocket* user) CXX11_OVERRIDE
	{
		InitSession(user, false);
	}

	void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
	{
		CloseSession(&sessions[user->GetFd()]);
	}

	int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
	{
		issl_session* session = &sessions[user->GetFd()];

		if (!session->sess)
		{
			CloseSession(session);
			user->SetError("No SSL session");
			return -1;
		}

		if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
		{
			// The handshake isn't finished, try to finish it.

			if(!Handshake(session, user))
			{
				if (session->status != ISSL_CLOSING)
					return 0;
				return -1;
			}
		}

		// If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.

		if (session->status == ISSL_HANDSHAKEN)
		{
			char* buffer = ServerInstance->GetReadBuffer();
			size_t bufsiz = ServerInstance->Config->NetBufferSize;
			int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
			if (ret > 0)
			{
				recvq.append(buffer, ret);
				return 1;
			}
			else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
			{
				return 0;
			}
			else if (ret == 0)
			{
				user->SetError("Connection closed");
				CloseSession(session);
				return -1;
			}
			else
			{
				user->SetError(gnutls_strerror(ret));
				CloseSession(session);
				return -1;
			}
		}
		else if (session->status == ISSL_CLOSING)
			return -1;

		return 0;
	}

	int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
	{
		issl_session* session = &sessions[user->GetFd()];

		if (!session->sess)
		{
			CloseSession(session);
			user->SetError("No SSL session");
			return -1;
		}

		if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
		{
			// The handshake isn't finished, try to finish it.
			Handshake(session, user);
			if (session->status != ISSL_CLOSING)
				return 0;
			return -1;
		}

		int ret = 0;

		if (session->status == ISSL_HANDSHAKEN)
		{
			ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());

			if (ret == (int)sendq.length())
			{
				ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
				return 1;
			}
			else if (ret > 0)
			{
				sendq = sendq.substr(ret);
				ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
				return 0;
			}
			else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
			{
				ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
				return 0;
			}
			else // (ret < 0)
			{
				user->SetError(gnutls_strerror(ret));
				CloseSession(session);
				return -1;
			}
		}

		return 0;
	}

	ssl_cert* GetCertificate(StreamSocket* sock) CXX11_OVERRIDE
	{
		int fd = sock->GetFd();
		issl_session* session = &sessions[fd];
		return session->cert;
	}

	void TellCiphersAndFingerprint(LocalUser* user)
	{
		const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
		if (sess)
		{
			std::string text = "*** You are connected using SSL cipher '";

			text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
			text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
			text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");

			ssl_cert* cert = sessions[user->eh.GetFd()].cert;
			if (!cert->fingerprint.empty())
				text += " and your SSL fingerprint is " + cert->fingerprint;

			user->WriteNotice(text);
		}
	}
};

class CommandStartTLS : public SplitCommand
{
	IOHook& hook;

 public:
	bool enabled;
	CommandStartTLS(Module* mod, IOHook& Hook)
		: SplitCommand(mod, "STARTTLS")
		, hook(Hook)
	{
		enabled = true;
		works_before_reg = true;
	}

	CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
	{
		if (!enabled)
		{
			user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
			return CMD_FAILURE;
		}

		if (user->registered == REG_ALL)
		{
			user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
		}
		else
		{
			if (!user->eh.GetIOHook())
			{
				user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
				/* We need to flush the write buffer prior to adding the IOHook,
				 * otherwise we'll be sending this line inside the SSL session - which
				 * won't start its handshake until the client gets this line. Currently,
				 * we assume the write will not block here; this is usually safe, as
				 * STARTTLS is sent very early on in the registration phase, where the
				 * user hasn't built up much sendq. Handling a blocked write here would
				 * be very annoying.
				 */
				user->eh.DoWrite();
				user->eh.AddIOHook(&hook);
				hook.OnStreamSocketAccept(&user->eh, NULL, NULL);
			}
			else
				user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
		}

		return CMD_FAILURE;
	}
};

class ModuleSSLGnuTLS : public Module
{
	GnuTLSIOHook iohook;

	gnutls_dh_params_t dh_params;

	std::string sslports;

	bool cred_alloc;
	bool dh_alloc;

	RandGen randhandler;
	CommandStartTLS starttls;

	GenericCap capHandler;

 public:
	ModuleSSLGnuTLS()
		: iohook(this), starttls(this, iohook), capHandler(this, "tls")
	{
		gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);

		gnutls_global_init(); // This must be called once in the program
		gnutls_x509_privkey_init(&x509_key);

		#ifdef GNUTLS_NEW_PRIO_API
		// Init this here so it's always initialized, avoids an extra boolean
		gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
		#endif

		cred_alloc = false;
		dh_alloc = false;
	}

	void init() CXX11_OVERRIDE
	{
		// Needs the flag as it ignores a plain /rehash
		OnModuleRehash(NULL,"ssl");

		ServerInstance->GenRandom = &randhandler;

		// Void return, guess we assume success
		gnutls_certificate_set_dh_params(iohook.x509_cred, dh_params);

		ServerInstance->Modules->AddService(iohook);
		ServerInstance->Modules->AddService(starttls);
	}

	void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
	{
		sslports.clear();

		ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
		starttls.enabled = Conf->getBool("starttls", true);

		if (Conf->getBool("showports", true))
		{
			sslports = Conf->getString("advertisedports");
			if (!sslports.empty())
				return;

			for (size_t i = 0; i < ServerInstance->ports.size(); i++)
			{
				ListenSocket* port = ServerInstance->ports[i];
				if (port->bind_tag->getString("ssl") != "gnutls")
					continue;

				const std::string& portid = port->bind_desc;
				ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Enabling SSL for port %s", portid.c_str());

				if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
				{
					/*
					 * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
					 * the IP:port in ISUPPORT.
					 *
					 * We used to advertise all ports seperated by a ';' char that matched the above criteria,
					 * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
					 * To solve this by default we now only display the first IP:port found and let the user
					 * configure the exact value for the 005 token, if necessary.
					 */
					sslports = portid;
					break;
				}
			}
		}
	}

	void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
	{
		if(param != "ssl")
			return;

		std::string keyfile;
		std::string certfile;
		std::string cafile;
		std::string crlfile;

		ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");

		cafile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("cafile", "ca.pem"));
		crlfile	= ServerInstance->Config->Paths.PrependConfig(Conf->getString("crlfile", "crl.pem"));
		certfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("certfile", "cert.pem"));
		keyfile	= ServerInstance->Config->Paths.PrependConfig(Conf->getString("keyfile", "key.pem"));
		int dh_bits = Conf->getInt("dhbits");
		std::string hashname = Conf->getString("hash", "md5");

		// The GnuTLS manual states that the gnutls_set_default_priority()
		// call we used previously when initializing the session is the same
		// as setting the "NORMAL" priority string.
		// Thus if the setting below is not in the config we will behave exactly
		// the same as before, when the priority setting wasn't available.
		std::string priorities = Conf->getString("priority", "NORMAL");

		if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
			dh_bits = 1024;

		iohook.dh_bits = dh_bits;

		// As older versions of gnutls can't do this, let's disable it where needed.
#ifdef GNUTLS_HAS_MAC_GET_ID
		// As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
		// There is no gnutls_dig_get_id() at the moment, but it may come later
		iohook.hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
		if (iohook.hash == GNUTLS_DIG_UNKNOWN)
			throw ModuleException("Unknown hash type " + hashname);

		// Check if the user is walking around with their head in the ass,
		// giving us something that is a valid MAC but not digest
		gnutls_hash_hd_t is_digest;
		if (gnutls_hash_init(&is_digest, iohook.hash) < 0)
			throw ModuleException("Unknown hash type " + hashname);
		gnutls_hash_deinit(is_digest, NULL);
#else
		if (hashname == "md5")
			iohook.hash = GNUTLS_DIG_MD5;
		else if (hashname == "sha1")
			iohook.hash = GNUTLS_DIG_SHA1;
		else
			throw ModuleException("Unknown hash type " + hashname);
#endif

		int ret;

		if (dh_alloc)
		{
			gnutls_dh_params_deinit(dh_params);
			dh_alloc = false;
			dh_params = NULL;
		}

		if (cred_alloc)
		{
			// Deallocate the old credentials
			gnutls_certificate_free_credentials(iohook.x509_cred);

			for(unsigned int i=0; i < x509_certs.size(); i++)
				gnutls_x509_crt_deinit(x509_certs[i]);
			x509_certs.clear();
		}

		ret = gnutls_certificate_allocate_credentials(&iohook.x509_cred);
		cred_alloc = (ret >= 0);
		if (!cred_alloc)
			ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to allocate certificate credentials: %s", gnutls_strerror(ret));

		if((ret =gnutls_certificate_set_x509_trust_file(iohook.x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
			ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));

		if((ret = gnutls_certificate_set_x509_crl_file (iohook.x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
			ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));

		FileReader reader;

		reader.Load(certfile);
		std::string cert_string = reader.GetString();
		gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), static_cast<unsigned int>(cert_string.length()) };

		reader.Load(keyfile);
		std::string key_string = reader.GetString();
		gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), static_cast<unsigned int>(key_string.length()) };

		// If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
		unsigned int certcount = 3;
		x509_certs.resize(certcount);
		ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
		if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
		{
			// the buffer wasn't big enough to hold all certs but gnutls updated certcount to the number of available certs, try again with a bigger buffer
			x509_certs.resize(certcount);
			ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
		}

		if (ret <= 0)
		{
			// clear the vector so we won't call gnutls_x509_crt_deinit() on the (uninited) certs later
			x509_certs.clear();
			throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + ((ret < 0) ? (std::string(gnutls_strerror(ret))) : "No certs could be read"));
		}
		x509_certs.resize(ret);

		if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
			throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));

		if((ret = gnutls_certificate_set_x509_key(iohook.x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
			throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));

		#ifdef GNUTLS_NEW_PRIO_API
		// It's safe to call this every time as we cannot have this uninitialized, see constructor and below.
		gnutls_priority_deinit(iohook.priority);

		// Try to set the priorities for ciphers, kex methods etc. to the user supplied string
		// If the user did not supply anything then the string is already set to "NORMAL"
		const char* priocstr = priorities.c_str();
		const char* prioerror;

		if ((ret = gnutls_priority_init(&iohook.priority, priocstr, &prioerror)) < 0)
		{
			// gnutls did not understand the user supplied string, log and fall back to the default priorities
			ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to set priorities to \"%s\": %s Syntax error at position %u, falling back to default (NORMAL)", priorities.c_str(), gnutls_strerror(ret), (unsigned int) (prioerror - priocstr));
			gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
		}

		#else
		if (priorities != "NORMAL")
			ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "You've set <gnutls:priority> to a value other than the default, but this is only supported with GnuTLS v2.1.7 or newer. Your GnuTLS version is older than that so the option will have no effect.");
		#endif

		#if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
		gnutls_certificate_client_set_retrieve_function (iohook.x509_cred, cert_callback);
		#else
		gnutls_certificate_set_retrieve_function (iohook.x509_cred, cert_callback);
		#endif
		ret = gnutls_dh_params_init(&dh_params);
		dh_alloc = (ret >= 0);
		if (!dh_alloc)
		{
			ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to initialise DH parameters: %s", gnutls_strerror(ret));
			return;
		}

		std::string dhfile = Conf->getString("dhfile");
		if (!dhfile.empty())
		{
			// Try to load DH params from file
			reader.Load(dhfile);
			std::string dhstring = reader.GetString();
			gnutls_datum_t dh_datum = { (unsigned char*)dhstring.data(), static_cast<unsigned int>(dhstring.length()) };

			if ((ret = gnutls_dh_params_import_pkcs3(dh_params, &dh_datum, GNUTLS_X509_FMT_PEM)) < 0)
			{
				// File unreadable or GnuTLS was unhappy with the contents, generate the DH primes now
				ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Generating DH parameters because I failed to load them from file '%s': %s", dhfile.c_str(), gnutls_strerror(ret));
				GenerateDHParams();
			}
		}
		else
		{
			GenerateDHParams();
		}
	}

	void GenerateDHParams()
	{
 		// Generate Diffie Hellman parameters - for use with DHE
		// kx algorithms. These should be discarded and regenerated
		// once a day, once a week or once a month. Depending on the
		// security requirements.

		if (!dh_alloc)
			return;

		int ret;

		if((ret = gnutls_dh_params_generate2(dh_params, iohook.dh_bits)) < 0)
			ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to generate DH parameters (%d bits): %s", iohook.dh_bits, gnutls_strerror(ret));
	}

	~ModuleSSLGnuTLS()
	{
		for(unsigned int i=0; i < x509_certs.size(); i++)
			gnutls_x509_crt_deinit(x509_certs[i]);

		gnutls_x509_privkey_deinit(x509_key);
		#ifdef GNUTLS_NEW_PRIO_API
		gnutls_priority_deinit(iohook.priority);
		#endif

		if (dh_alloc)
			gnutls_dh_params_deinit(dh_params);
		if (cred_alloc)
			gnutls_certificate_free_credentials(iohook.x509_cred);

		gnutls_global_deinit();
		ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
	}

	void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
	{
		if(target_type == TYPE_USER)
		{
			LocalUser* user = IS_LOCAL(static_cast<User*>(item));

			if (user && user->eh.GetIOHook() == &iohook)
			{
				// User is using SSL, they're a local user, and they're using one of *our* SSL ports.
				// Potentially there could be multiple SSL modules loaded at once on different ports.
				ServerInstance->Users->QuitUser(user, "SSL module unloading");
			}
		}
	}

	Version GetVersion() CXX11_OVERRIDE
	{
		return Version("Provides SSL support for clients", VF_VENDOR);
	}

	void On005Numeric(std::map<std::string, std::string>& tokens) CXX11_OVERRIDE
	{
		if (!sslports.empty())
			tokens["SSL"] = sslports;
		if (starttls.enabled)
			tokens["STARTTLS"];
	}

	void OnHookIO(StreamSocket* user, ListenSocket* lsb) CXX11_OVERRIDE
	{
		if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
		{
			/* Hook the user with our module */
			user->AddIOHook(&iohook);
		}
	}

	void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
	{
		if (user->eh.GetIOHook() == &iohook)
			iohook.TellCiphersAndFingerprint(user);
	}

	void OnEvent(Event& ev) CXX11_OVERRIDE
	{
		if (starttls.enabled)
			capHandler.HandleEvent(ev);
	}
};

MODULE_INIT(ModuleSSLGnuTLS)