summaryrefslogtreecommitdiff
path: root/src/modules/extra/m_ssl_gnutls.cpp
blob: 96f35e14bd084946e0e0432b4077beb7b7831d4f (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
941
/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
 * See: http://www.inspircd.org/wiki/index.php/Credits
 *
 * This program is free but copyrighted software; see
 *	    the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#include "inspircd.h"
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#include "transport.h"
#include "m_cap.h"

#ifdef WINDOWS
#pragma comment(lib, "libgnutls-13.lib")
#endif

/* $ModDesc: Provides SSL support for clients */
/* $CompileFlags: exec("libgnutls-config --cflags") */
/* $LinkerFlags: rpath("libgnutls-config --libs") exec("libgnutls-config --libs") */
/* $ModDep: transport.h */
/* $CopyInstall: conf/key.pem $(CONPATH) */
/* $CopyInstall: conf/cert.pem $(CONPATH) */

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

bool isin(const std::string &host, int port, const std::vector<std::string> &portlist)
{
	if (std::find(portlist.begin(), portlist.end(), "*:" + ConvToStr(port)) != portlist.end())
		return true;

	if (std::find(portlist.begin(), portlist.end(), ":" + ConvToStr(port)) != portlist.end())
		return true;

	return std::find(portlist.begin(), portlist.end(), host + ":" + ConvToStr(port)) != portlist.end();
}

/** Represents an SSL user's extra data
 */
class issl_session : public classbase
{
public:
	issl_session()
	{
		sess = NULL;
	}

	gnutls_session_t sess;
	issl_status status;
	std::string outbuf;
	int inbufoffset;
	char* inbuf;
	int fd;
};

class CommandStartTLS : public Command
{
	Module* Caller;
 public:
	/* Command 'dalinfo', takes no parameters and needs no special modes */
	CommandStartTLS (InspIRCd* Instance, Module* mod) : Command(Instance,"STARTTLS", 0, 0, true), Caller(mod)
	{
		this->source = "m_ssl_gnutls.so";
	}

	CmdResult Handle (const std::vector<std::string> &parameters, User *user)
	{
		/* changed from == REG_ALL to catch clients sending STARTTLS
		 * after NICK and USER but before OnUserConnect completes and
		 * give a proper error message (see bug #645) - dz
		 */
		if (user->registered != REG_NONE)
		{
			ServerInstance->Users->QuitUser(user, "STARTTLS is not permitted after client registration has started");
		}
		else
		{
			if (!user->GetIOHook())
			{
				user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
				user->AddIOHook(Caller);
				Caller->OnRawSocketAccept(user->GetFd(), user->GetIPString(), user->GetPort());
			}
			else
				user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
		}

		return CMD_FAILURE;
	}
};

class ModuleSSLGnuTLS : public Module
{

	ConfigReader* Conf;

	char* dummy;

	std::vector<std::string> listenports;

	int inbufsize;
	issl_session* sessions;

	gnutls_certificate_credentials x509_cred;
	gnutls_dh_params dh_params;

	std::string keyfile;
	std::string certfile;
	std::string cafile;
	std::string crlfile;
	std::string sslports;
	int dh_bits;

	int clientactive;
	bool cred_alloc;

	CommandStartTLS* starttls;

 public:

	ModuleSSLGnuTLS(InspIRCd* Me)
		: Module(Me)
	{
		ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);

		sessions = new issl_session[ServerInstance->SE->GetMaxFds()];

		// Not rehashable...because I cba to reduce all the sizes of existing buffers.
		inbufsize = ServerInstance->Config->NetBufferSize;

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

		cred_alloc = false;
		// Needs the flag as it ignores a plain /rehash
		OnRehash(NULL,"ssl");

		// Void return, guess we assume success
		gnutls_certificate_set_dh_params(x509_cred, dh_params);
		Implementation eventlist[] = { I_On005Numeric, I_OnRawSocketConnect, I_OnRawSocketAccept, I_OnRawSocketClose, I_OnRawSocketRead, I_OnRawSocketWrite, I_OnCleanup,
			I_OnBufferFlushed, I_OnRequest, I_OnSyncUserMetaData, I_OnDecodeMetaData, I_OnUnloadModule, I_OnRehash, I_OnWhois, I_OnPostConnect, I_OnEvent, I_OnHookUserIO };
		ServerInstance->Modules->Attach(eventlist, this, 17);

		starttls = new CommandStartTLS(ServerInstance, this);
		ServerInstance->AddCommand(starttls);
	}

	virtual void OnRehash(User* user, const std::string &param)
	{
		Conf = new ConfigReader(ServerInstance);

		listenports.clear();
		clientactive = 0;
		sslports.clear();

		for(int index = 0; index < Conf->Enumerate("bind"); index++)
		{
			// For each <bind> tag
			std::string x = Conf->ReadValue("bind", "type", index);
			if(((x.empty()) || (x == "clients")) && (Conf->ReadValue("bind", "ssl", index) == "gnutls"))
			{
				// Get the port we're meant to be listening on with SSL
				std::string port = Conf->ReadValue("bind", "port", index);
				std::string addr = Conf->ReadValue("bind", "address", index);

				irc::portparser portrange(port, false);
				long portno = -1;
				while ((portno = portrange.GetToken()))
				{
					clientactive++;
					try
					{
						listenports.push_back(addr + ":" + ConvToStr(portno));

						for (size_t i = 0; i < ServerInstance->Config->ports.size(); i++)
							if ((ServerInstance->Config->ports[i]->GetPort() == portno) && (ServerInstance->Config->ports[i]->GetIP() == addr))
								ServerInstance->Config->ports[i]->SetDescription("ssl");
						ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %ld", portno);

						sslports.append((addr.empty() ? "*" : addr)).append(":").append(ConvToStr(portno)).append(";");
					}
					catch (ModuleException &e)
					{
						ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: FAILED to enable SSL on port %ld: %s. Maybe it's already hooked by the same port on a different IP, or you have an other SSL or similar module loaded?", portno, e.GetReason());
					}
				}
			}
		}

		if (!sslports.empty())
			sslports.erase(sslports.end() - 1);

		if(param != "ssl")
		{
			delete Conf;
			return;
		}

		std::string confdir(ServerInstance->ConfigFileName);
		// +1 so we the path ends with a /
		confdir = confdir.substr(0, confdir.find_last_of('/') + 1);

		cafile	= Conf->ReadValue("gnutls", "cafile", 0);
		crlfile	= Conf->ReadValue("gnutls", "crlfile", 0);
		certfile	= Conf->ReadValue("gnutls", "certfile", 0);
		keyfile	= Conf->ReadValue("gnutls", "keyfile", 0);
		dh_bits	= Conf->ReadInteger("gnutls", "dhbits", 0, false);

		// Set all the default values needed.
		if (cafile.empty())
			cafile = "ca.pem";

		if (crlfile.empty())
			crlfile = "crl.pem";

		if (certfile.empty())
			certfile = "cert.pem";

		if (keyfile.empty())
			keyfile = "key.pem";

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

		// Prepend relative paths with the path to the config directory.
		if ((cafile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(cafile)))
			cafile = confdir + cafile;

		if ((crlfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(crlfile)))
			crlfile = confdir + crlfile;

		if ((certfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(certfile)))
			certfile = confdir + certfile;

		if ((keyfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(keyfile)))
			keyfile = confdir + keyfile;

		int ret;
		
		if (cred_alloc)
		{
			// Deallocate the old credentials
			gnutls_dh_params_deinit(dh_params);
			gnutls_certificate_free_credentials(x509_cred);
		}
		else
			cred_alloc = true;
		
		if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
			ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
		
		if((ret = gnutls_dh_params_init(&dh_params)) < 0)
			ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
		
		if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
			ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));

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

		if((ret = gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
		{
			// If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
			throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + ", key: " + keyfile + "): " + std::string(gnutls_strerror(ret)));
		}

		// This may be on a large (once a day or week) timer eventually.
		GenerateDHParams();

		delete Conf;
	}

	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.

		int ret;

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

	virtual ~ModuleSSLGnuTLS()
	{
		gnutls_dh_params_deinit(dh_params);
		gnutls_certificate_free_credentials(x509_cred);
		gnutls_global_deinit();
		ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
		delete[] sessions;
	}

	virtual void OnCleanup(int target_type, void* item)
	{
		if(target_type == TYPE_USER)
		{
			User* user = (User*)item;

			if (user->GetIOHook() == this)
			{
				// 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");
				user->DelIOHook();
			}
			if (user->GetExt("ssl_cert", dummy))
			{
				ssl_cert* tofree;
				user->GetExt("ssl_cert", tofree);
				delete tofree;
				user->Shrink("ssl_cert");
			}
		}
	}

	virtual void OnUnloadModule(Module* mod, const std::string &name)
	{
		if(mod == this)
		{
			for(unsigned int i = 0; i < listenports.size(); i++)
			{
				for (size_t j = 0; j < ServerInstance->Config->ports.size(); j++)
					if (listenports[i] == (ServerInstance->Config->ports[j]->GetIP()+":"+ConvToStr(ServerInstance->Config->ports[j]->GetPort())))
						ServerInstance->Config->ports[j]->SetDescription("plaintext");
			}
		}
	}

	virtual Version GetVersion()
	{
		return Version("$Id$", VF_VENDOR, API_VERSION);
	}


	virtual void On005Numeric(std::string &output)
	{
		output.append(" SSL=" + sslports);
	}

	virtual void OnHookUserIO(User* user, const std::string &targetip)
	{
		if (!user->GetIOHook() && isin(targetip,user->GetPort(),listenports))
		{
			/* Hook the user with our module */
			user->AddIOHook(this);
		}
	}

	virtual const char* OnRequest(Request* request)
	{
		ISHRequest* ISR = (ISHRequest*)request;
		if (strcmp("IS_NAME", request->GetId()) == 0)
		{
			return "gnutls";
		}
		else if (strcmp("IS_HOOK", request->GetId()) == 0)
		{
			const char* ret = "OK";
			try
			{
				ret = ISR->Sock->AddIOHook((Module*)this) ? "OK" : NULL;
			}
			catch (ModuleException &e)
			{
				return NULL;
			}
			return ret;
		}
		else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
		{
			return ISR->Sock->DelIOHook() ? "OK" : NULL;
		}
		else if (strcmp("IS_HSDONE", request->GetId()) == 0)
		{
			if (ISR->Sock->GetFd() < 0)
				return "OK";

			issl_session* session = &sessions[ISR->Sock->GetFd()];
			return (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE) ? NULL : "OK";
		}
		else if (strcmp("IS_ATTACH", request->GetId()) == 0)
		{
			if (ISR->Sock->GetFd() > -1)
			{
				issl_session* session = &sessions[ISR->Sock->GetFd()];
				if (session->sess)
				{
					if ((Extensible*)ServerInstance->FindDescriptor(ISR->Sock->GetFd()) == (Extensible*)(ISR->Sock))
					{
						VerifyCertificate(session, (BufferedSocket*)ISR->Sock);
						return "OK";
					}
				}
			}
		}
		return NULL;
	}


	virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
	{
		/* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
		if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
			return;

		issl_session* session = &sessions[fd];

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

		session->fd = fd;
		session->inbuf = new char[inbufsize];
		session->inbufoffset = 0;

		gnutls_init(&session->sess, GNUTLS_SERVER);

		gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
		gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
		gnutls_dh_set_prime_bits(session->sess, dh_bits);

		/* This is an experimental change to avoid a warning on 64bit systems about casting between integer and pointer of different sizes
		 * This needs testing, but it's easy enough to rollback if need be
		 * Old: gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
		 * New: gnutls_transport_set_ptr(session->sess, &fd); // Give gnutls the fd for the socket.
		 *
		 * With testing this seems to...not work :/
		 */

		gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.

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

		Handshake(session);
	}

	virtual void OnRawSocketConnect(int fd)
	{
		/* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
		if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
			return;

		issl_session* session = &sessions[fd];

		session->fd = fd;
		session->inbuf = new char[inbufsize];
		session->inbufoffset = 0;

		gnutls_init(&session->sess, GNUTLS_CLIENT);

		gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
		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, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.

		Handshake(session);
	}

	virtual void OnRawSocketClose(int fd)
	{
		/* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
		if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds()))
			return;

		CloseSession(&sessions[fd]);

		EventHandler* user = ServerInstance->SE->GetRef(fd);

		if ((user) && (user->GetExt("ssl_cert", dummy)))
		{
			ssl_cert* tofree;
			user->GetExt("ssl_cert", tofree);
			delete tofree;
			user->Shrink("ssl_cert");
		}
	}

	virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
	{
		/* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
		if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
			return 0;

		issl_session* session = &sessions[fd];

		if (!session->sess)
		{
			readresult = 0;
			CloseSession(session);
			return 1;
		}

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

			if(!Handshake(session))
			{
				// Couldn't resume handshake.
				return -1;
			}
		}
		else if (session->status == ISSL_HANDSHAKING_WRITE)
		{
			errno = EAGAIN;
			MakePollWrite(session);
			return -1;
		}

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

		if (session->status == ISSL_HANDSHAKEN)
		{
			// Is this right? Not sure if the unencrypted data is garaunteed to be the same length.
			// Read into the inbuffer, offset from the beginning by the amount of data we have that insp hasn't taken yet.
			int ret = gnutls_record_recv(session->sess, session->inbuf + session->inbufoffset, inbufsize - session->inbufoffset);

			if (ret == 0)
			{
				// Client closed connection.
				readresult = 0;
				CloseSession(session);
				return 1;
			}
			else if (ret < 0)
			{
				if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
				{
					errno = EAGAIN;
					return -1;
				}
				else
				{
					ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
							"m_ssl_gnutls.so: Error while reading on fd %d: %s",
							session->fd, gnutls_strerror(ret));
					readresult = 0;
					CloseSession(session);
				}
			}
			else
			{
				// Read successfully 'ret' bytes into inbuf + inbufoffset
				// There are 'ret' + 'inbufoffset' bytes of data in 'inbuf'
				// 'buffer' is 'count' long

				unsigned int length = ret + session->inbufoffset;

				if(count <= length)
				{
					memcpy(buffer, session->inbuf, count);
					// Move the stuff left in inbuf to the beginning of it
					memmove(session->inbuf, session->inbuf + count, (length - count));
					// Now we need to set session->inbufoffset to the amount of data still waiting to be handed to insp.
					session->inbufoffset = length - count;
					// Insp uses readresult as the count of how much data there is in buffer, so:
					readresult = count;
				}
				else
				{
					// There's not as much in the inbuf as there is space in the buffer, so just copy the whole thing.
					memcpy(buffer, session->inbuf, length);
					// Zero the offset, as there's nothing there..
					session->inbufoffset = 0;
					// As above
					readresult = length;
				}
			}
		}
		else if(session->status == ISSL_CLOSING)
			readresult = 0;

		return 1;
	}

	virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
	{
		/* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
		if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
			return 0;

		issl_session* session = &sessions[fd];
		const char* sendbuffer = buffer;

		if (!session->sess)
		{
			CloseSession(session);
			return 1;
		}

		session->outbuf.append(sendbuffer, count);
		sendbuffer = session->outbuf.c_str();
		count = session->outbuf.size();

		if (session->status == ISSL_HANDSHAKING_WRITE)
		{
			// The handshake isn't finished, try to finish it.
			Handshake(session);
			errno = EAGAIN;
			return -1;
		}

		int ret = 0;

		if (session->status == ISSL_HANDSHAKEN)
		{
			ret = gnutls_record_send(session->sess, sendbuffer, count);

			if (ret == 0)
			{
				CloseSession(session);
			}
			else if (ret < 0)
			{
				if(ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED)
				{
					ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
							"m_ssl_gnutls.so: Error while writing to fd %d: %s",
							session->fd, gnutls_strerror(ret));
					CloseSession(session);
				}
				else
				{
					errno = EAGAIN;
				}
			}
			else
			{
				session->outbuf = session->outbuf.substr(ret);
			}
		}

		MakePollWrite(session);

		/* Who's smart idea was it to return 1 when we havent written anything?
		 * This fucks the buffer up in BufferedSocket :p
		 */
		return ret < 1 ? 0 : ret;
	}

	// :kenny.chatspike.net 320 Om Epy|AFK :is a Secure Connection
	virtual void OnWhois(User* source, User* dest)
	{
		if (!clientactive)
			return;

		// Bugfix, only send this numeric for *our* SSL users
		if (dest->GetExt("ssl", dummy) || ((IS_LOCAL(dest) && (dest->GetIOHook() == this))))
		{
			ServerInstance->SendWhoisLine(source, dest, 320, "%s %s :is using a secure connection", source->nick.c_str(), dest->nick.c_str());
		}
	}

	virtual void OnSyncUserMetaData(User* user, Module* proto, void* opaque, const std::string &extname, bool displayable)
	{
		// check if the linking module wants to know about OUR metadata
		if(extname == "ssl")
		{
			// check if this user has an swhois field to send
			if(user->GetExt(extname, dummy))
			{
				// call this function in the linking module, let it format the data how it
				// sees fit, and send it on its way. We dont need or want to know how.
				proto->ProtoSendMetaData(opaque, TYPE_USER, user, extname, displayable ? "Enabled" : "ON");
			}
		}
	}

	virtual void OnDecodeMetaData(int target_type, void* target, const std::string &extname, const std::string &extdata)
	{
		// check if its our metadata key, and its associated with a user
		if ((target_type == TYPE_USER) && (extname == "ssl"))
		{
			User* dest = (User*)target;
			// if they dont already have an ssl flag, accept the remote server's
			if (!dest->GetExt(extname, dummy))
			{
				dest->Extend(extname, "ON");
			}
		}
	}

	bool Handshake(issl_session* session)
	{
		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;
				}
				else
				{
					// gnutls_handshake() wants to write() again.
					session->status = ISSL_HANDSHAKING_WRITE;
					MakePollWrite(session);
				}
			}
			else
			{
				// Handshake failed.
				ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
						"m_ssl_gnutls.so: Handshake failed on fd %d: %s",
						session->fd, gnutls_strerror(ret));
				CloseSession(session);
				session->status = ISSL_CLOSING;
			}

			return false;
		}
		else
		{
			// Handshake complete.
			// This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
			User* extendme = ServerInstance->FindDescriptor(session->fd);
			if (extendme)
			{
				if (!extendme->GetExt("ssl", dummy))
					extendme->Extend("ssl", "ON");
			}

			// Change the seesion state
			session->status = ISSL_HANDSHAKEN;

			// Finish writing, if any left
			MakePollWrite(session);

			return true;
		}
	}

	virtual void OnPostConnect(User* user)
	{
		// This occurs AFTER OnUserConnect so we can be sure the
		// protocol module has propagated the NICK message.
		if (user->GetIOHook() == this && (IS_LOCAL(user)))
		{
			// Tell whatever protocol module we're using that we need to inform other servers of this metadata NOW.
			ServerInstance->PI->SendMetaData(user, TYPE_USER, "SSL", "on");

			VerifyCertificate(&sessions[user->GetFd()],user);
			if (sessions[user->GetFd()].sess)
			{
				std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->GetFd()].sess));
				cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->GetFd()].sess))).append("-");
				cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->GetFd()].sess)));
				user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
			}
		}
	}

	void MakePollWrite(issl_session* session)
	{
		//OnRawSocketWrite(session->fd, NULL, 0);
		EventHandler* eh = ServerInstance->FindDescriptor(session->fd);
		if (eh)
			ServerInstance->SE->WantWrite(eh);
	}

	virtual void OnBufferFlushed(User* user)
	{
		if (user->GetIOHook() == this)
		{
			issl_session* session = &sessions[user->GetFd()];
			if (session && session->outbuf.size())
				OnRawSocketWrite(user->GetFd(), NULL, 0);
		}
	}

	void CloseSession(issl_session* session)
	{
		if(session->sess)
		{
			gnutls_bye(session->sess, GNUTLS_SHUT_WR);
			gnutls_deinit(session->sess);
		}

		if(session->inbuf)
		{
			delete[] session->inbuf;
		}

		session->outbuf.clear();
		session->inbuf = NULL;
		session->sess = NULL;
		session->status = ISSL_NONE;
	}

	void VerifyCertificate(issl_session* session, Extensible* 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 name[MAXBUF];
		unsigned char digest[MAXBUF];
		size_t digest_size = sizeof(digest);
		size_t name_size = sizeof(name);
		ssl_cert* certinfo = new ssl_cert;

		user->Extend("ssl_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->data.insert(std::make_pair("error",std::string(gnutls_strerror(ret))));
			return;
		}

		if (status & GNUTLS_CERT_INVALID)
		{
			certinfo->data.insert(std::make_pair("invalid",ConvToStr(1)));
		}
		else
		{
			certinfo->data.insert(std::make_pair("invalid",ConvToStr(0)));
		}
		if (status & GNUTLS_CERT_SIGNER_NOT_FOUND)
		{
			certinfo->data.insert(std::make_pair("unknownsigner",ConvToStr(1)));
		}
		else
		{
			certinfo->data.insert(std::make_pair("unknownsigner",ConvToStr(0)));
		}
		if (status & GNUTLS_CERT_REVOKED)
		{
			certinfo->data.insert(std::make_pair("revoked",ConvToStr(1)));
		}
		else
		{
			certinfo->data.insert(std::make_pair("revoked",ConvToStr(0)));
		}
		if (status & GNUTLS_CERT_SIGNER_NOT_CA)
		{
			certinfo->data.insert(std::make_pair("trusted",ConvToStr(0)));
		}
		else
		{
			certinfo->data.insert(std::make_pair("trusted",ConvToStr(1)));
		}

		/* 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->data.insert(std::make_pair("error","No X509 keys sent"));
			return;
		}

		ret = gnutls_x509_crt_init(&cert);
		if (ret < 0)
		{
			certinfo->data.insert(std::make_pair("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->data.insert(std::make_pair("error","No certificate was found"));
			return;
		}

		/* 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->data.insert(std::make_pair("error",gnutls_strerror(ret)));
			return;
		}

		gnutls_x509_crt_get_dn(cert, name, &name_size);

		certinfo->data.insert(std::make_pair("dn",name));

		gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);

		certinfo->data.insert(std::make_pair("issuer",name));

		if ((ret = gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_MD5, digest, &digest_size)) < 0)
		{
			certinfo->data.insert(std::make_pair("error",gnutls_strerror(ret)));
		}
		else
		{
			certinfo->data.insert(std::make_pair("fingerprint",irc::hex(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->data.insert(std::make_pair("error","Not activated, or expired certificate"));
		}

		gnutls_x509_crt_deinit(cert);

		return;
	}

	void OnEvent(Event* ev)
	{
		GenericCapHandler(ev, "tls", "tls");
	}

	void Prioritize()
	{
		Module* server = ServerInstance->Modules->Find("m_spanningtree.so");
		ServerInstance->Modules->SetPriority(this, I_OnPostConnect, PRIO_AFTER, &server);
	}
};

MODULE_INIT(ModuleSSLGnuTLS)