src/modules/extra/m_ssl_gnutls.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2008 John Brooks <john.brooks@dereferenced.net>
   6  *   Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   8  *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
   9  *
  10  * This file is part of InspIRCd.  InspIRCd is free software: you can
  11  * redistribute it and/or modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation, version 2.
  13  *
  14  * This program is distributed in the hope that it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  16  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23
  24 #include "inspircd.h"
  25 #ifndef _WIN32
  26 #include <gcrypt.h>
  27 #endif
  28 #include <gnutls/gnutls.h>
  29 #include <gnutls/x509.h>
  30 #include "ssl.h"
  31 #include "m_cap.h"
  32
  33 #ifdef _WIN32
  34 # pragma comment(lib, "libgnutls-28.lib")
  35 #endif
  36
  37 /* $ModDesc: Provides SSL support for clients */
  38 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") exec("libgcrypt-config --cflags") */
  39 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") exec("libgcrypt-config --libs") */
  40 /* $NoPedantic */
  41
  42 #ifndef GNUTLS_VERSION_MAJOR
  43 #define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
  44 #define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
  45 #define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
  46 #endif
  47
  48 // These don't exist in older GnuTLS versions
  49 #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))
  50 #define GNUTLS_NEW_PRIO_API
  51 #endif
  52
  53 #if(GNUTLS_VERSION_MAJOR < 2)
  54 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  55 typedef gnutls_dh_params_t gnutls_dh_params;
  56 #endif
  57
  58 #if (defined(_WIN32) && (GNUTLS_VERSION_MAJOR > 2 || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR >= 12)))
  59 # define GNUTLS_HAS_RND
  60 # include <gnutls/crypto.h>
  61 #else
  62 # include <gcrypt.h>
  63 #endif
  64
  65 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  66
  67 struct SSLConfig : public refcountbase
  68 {
  69         gnutls_certificate_credentials_t x509_cred;
  70         std::vector<gnutls_x509_crt_t> x509_certs;
  71         gnutls_x509_privkey_t x509_key;
  72         gnutls_dh_params_t dh_params;
  73 #ifdef GNUTLS_NEW_PRIO_API
  74         gnutls_priority_t priority;
  75 #endif
  76
  77         SSLConfig()
  78                 : x509_cred(NULL)
  79                 , x509_key(NULL)
  80                 , dh_params(NULL)
  81 #ifdef GNUTLS_NEW_PRIO_API
  82                 , priority(NULL)
  83 #endif
  84         {
  85         }
  86
  87         ~SSLConfig()
  88         {
  89                 ServerInstance->Logs->Log("m_ssl_gnutls", DEBUG, "Destroying SSLConfig %p", (void*)this);
  90
  91                 if (x509_cred)
  92                         gnutls_certificate_free_credentials(x509_cred);
  93
  94                 for (unsigned int i = 0; i < x509_certs.size(); i++)
  95                         gnutls_x509_crt_deinit(x509_certs[i]);
  96
  97                 if (x509_key)
  98                         gnutls_x509_privkey_deinit(x509_key);
  99
 100                 if (dh_params)
 101                         gnutls_dh_params_deinit(dh_params);
 102
 103 #ifdef GNUTLS_NEW_PRIO_API
 104                 if (priority)
 105                         gnutls_priority_deinit(priority);
 106 #endif
 107         }
 108 };
 109
 110 static reference<SSLConfig> currconf;
 111
 112 static SSLConfig* GetSessionConfig(gnutls_session_t session);
 113
 114 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
 115 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
 116         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
 117
 118         st->type = GNUTLS_CRT_X509;
 119 #else
 120 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
 121         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr2_st * st) {
 122         st->cert_type = GNUTLS_CRT_X509;
 123         st->key_type = GNUTLS_PRIVKEY_X509;
 124 #endif
 125         SSLConfig* conf = GetSessionConfig(session);
 126         std::vector<gnutls_x509_crt_t>& x509_certs = conf->x509_certs;
 127         st->ncerts = x509_certs.size();
 128         st->cert.x509 = &x509_certs[0];
 129         st->key.x509 = conf->x509_key;
 130         st->deinit_all = 0;
 131
 132         return 0;
 133 }
 134
 135 class RandGen : public HandlerBase2<void, char*, size_t>
 136 {
 137  public:
 138         RandGen() {}
 139         void Call(char* buffer, size_t len)
 140         {
 141 #ifdef GNUTLS_HAS_RND
 142                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
 143 #else
 144                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
 145 #endif
 146         }
 147 };
 148
 149 /** Represents an SSL user's extra data
 150  */
 151 class issl_session
 152 {
 153 public:
 154         StreamSocket* socket;
 155         gnutls_session_t sess;
 156         issl_status status;
 157         reference<ssl_cert> cert;
 158         reference<SSLConfig> config;
 159
 160         issl_session() : socket(NULL), sess(NULL) {}
 161 };
 162
 163 static SSLConfig* GetSessionConfig(gnutls_session_t sess)
 164 {
 165         issl_session* session = reinterpret_cast<issl_session*>(gnutls_transport_get_ptr(sess));
 166         return session->config;
 167 }
 168
 169 class CommandStartTLS : public SplitCommand
 170 {
 171  public:
 172         bool enabled;
 173         CommandStartTLS (Module* mod) : SplitCommand(mod, "STARTTLS")
 174         {
 175                 enabled = true;
 176                 works_before_reg = true;
 177         }
 178
 179         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 180         {
 181                 if (!enabled)
 182                 {
 183                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 184                         return CMD_FAILURE;
 185                 }
 186
 187                 if (user->registered == REG_ALL)
 188                 {
 189                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 190                 }
 191                 else
 192                 {
 193                         if (!user->eh.GetIOHook())
 194                         {
 195                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 196                                 /* We need to flush the write buffer prior to adding the IOHook,
 197                                  * otherwise we'll be sending this line inside the SSL session - which
 198                                  * won't start its handshake until the client gets this line. Currently,
 199                                  * we assume the write will not block here; this is usually safe, as
 200                                  * STARTTLS is sent very early on in the registration phase, where the
 201                                  * user hasn't built up much sendq. Handling a blocked write here would
 202                                  * be very annoying.
 203                                  */
 204                                 user->eh.DoWrite();
 205                                 user->eh.AddIOHook(creator);
 206                                 creator->OnStreamSocketAccept(&user->eh, NULL, NULL);
 207                         }
 208                         else
 209                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 210                 }
 211
 212                 return CMD_FAILURE;
 213         }
 214 };
 215
 216 class ModuleSSLGnuTLS : public Module
 217 {
 218         issl_session* sessions;
 219
 220         gnutls_digest_algorithm_t hash;
 221
 222         std::string sslports;
 223         int dh_bits;
 224
 225         RandGen randhandler;
 226         CommandStartTLS starttls;
 227
 228         GenericCap capHandler;
 229         ServiceProvider iohook;
 230
 231         inline static const char* UnknownIfNULL(const char* str)
 232         {
 233                 return str ? str : "UNKNOWN";
 234         }
 235
 236         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 237         {
 238                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 239                 if (session->socket->GetEventMask() & FD_READ_WILL_BLOCK)
 240                 {
 241 #ifdef _WIN32
 242                         gnutls_transport_set_errno(session->sess, EAGAIN);
 243 #else
 244                         errno = EAGAIN;
 245 #endif
 246                         return -1;
 247                 }
 248
 249                 int rv = ServerInstance->SE->Recv(session->socket, reinterpret_cast<char *>(buffer), size, 0);
 250
 251 #ifdef _WIN32
 252                 if (rv < 0)
 253                 {
 254                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 255                          * and then set errno appropriately.
 256                          * The gnutls library may also have a different errno variable than us, see
 257                          * gnutls_transport_set_errno(3).
 258                          */
 259                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 260                 }
 261 #endif
 262
 263                 if (rv < (int)size)
 264                         ServerInstance->SE->ChangeEventMask(session->socket, FD_READ_WILL_BLOCK);
 265                 return rv;
 266         }
 267
 268         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 269         {
 270                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 271                 if (session->socket->GetEventMask() & FD_WRITE_WILL_BLOCK)
 272                 {
 273 #ifdef _WIN32
 274                         gnutls_transport_set_errno(session->sess, EAGAIN);
 275 #else
 276                         errno = EAGAIN;
 277 #endif
 278                         return -1;
 279                 }
 280
 281                 int rv = ServerInstance->SE->Send(session->socket, reinterpret_cast<const char *>(buffer), size, 0);
 282
 283 #ifdef _WIN32
 284                 if (rv < 0)
 285                 {
 286                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 287                          * and then set errno appropriately.
 288                          * The gnutls library may also have a different errno variable than us, see
 289                          * gnutls_transport_set_errno(3).
 290                          */
 291                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 292                 }
 293 #endif
 294
 295                 if (rv < (int)size)
 296                         ServerInstance->SE->ChangeEventMask(session->socket, FD_WRITE_WILL_BLOCK);
 297                 return rv;
 298         }
 299
 300  public:
 301
 302         ModuleSSLGnuTLS()
 303                 : starttls(this), capHandler(this, "tls"), iohook(this, "ssl/gnutls", SERVICE_IOHOOK)
 304         {
 305 #ifndef GNUTLS_HAS_RND
 306                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 307 #endif
 308
 309                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 310
 311                 gnutls_global_init(); // This must be called once in the program
 312         }
 313
 314         void init()
 315         {
 316                 currconf = new SSLConfig;
 317                 InitSSLConfig(currconf);
 318
 319                 ServerInstance->GenRandom = &randhandler;
 320
 321                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 322                         I_OnEvent, I_OnHookIO };
 323                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 324
 325                 ServerInstance->Modules->AddService(iohook);
 326                 ServerInstance->Modules->AddService(starttls);
 327         }
 328
 329         void OnRehash(User* user)
 330         {
 331                 sslports.clear();
 332
 333                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 334                 starttls.enabled = Conf->getBool("starttls", true);
 335
 336                 if (Conf->getBool("showports", true))
 337                 {
 338                         sslports = Conf->getString("advertisedports");
 339                         if (!sslports.empty())
 340                                 return;
 341
 342                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 343                         {
 344                                 ListenSocket* port = ServerInstance->ports[i];
 345                                 if (port->bind_tag->getString("ssl") != "gnutls")
 346                                         continue;
 347
 348                                 const std::string& portid = port->bind_desc;
 349                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 350
 351                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 352                                 {
 353                                         /*
 354                                          * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
 355                                          * the IP:port in ISUPPORT.
 356                                          *
 357                                          * We used to advertise all ports seperated by a ';' char that matched the above criteria,
 358                                          * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
 359                                          * To solve this by default we now only display the first IP:port found and let the user
 360                                          * configure the exact value for the 005 token, if necessary.
 361                                          */
 362                                         sslports = portid;
 363                                         break;
 364                                 }
 365                         }
 366                 }
 367         }
 368
 369         void OnModuleRehash(User* user, const std::string &param)
 370         {
 371                 if(param != "ssl")
 372                         return;
 373
 374                 reference<SSLConfig> newconf = new SSLConfig;
 375                 try
 376                 {
 377                         InitSSLConfig(newconf);
 378                 }
 379                 catch (ModuleException& ex)
 380                 {
 381                         ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls: Not applying new config. %s", ex.GetReason());
 382                         return;
 383                 }
 384
 385                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls: Applying new config, old config is in use by %d connection(s)", currconf->GetReferenceCount()-1);
 386                 currconf = newconf;
 387         }
 388
 389         void InitSSLConfig(SSLConfig* config)
 390         {
 391                 ServerInstance->Logs->Log("m_ssl_gnutls", DEBUG, "Initializing new SSLConfig %p", (void*)config);
 392
 393                 std::string keyfile;
 394                 std::string certfile;
 395                 std::string cafile;
 396                 std::string crlfile;
 397                 OnRehash(NULL);
 398
 399                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 400
 401                 cafile = Conf->getString("cafile", CONFIG_PATH "/ca.pem");
 402                 crlfile = Conf->getString("crlfile", CONFIG_PATH "/crl.pem");
 403                 certfile = Conf->getString("certfile", CONFIG_PATH "/cert.pem");
 404                 keyfile = Conf->getString("keyfile", CONFIG_PATH "/key.pem");
 405                 dh_bits = Conf->getInt("dhbits");
 406                 std::string hashname = Conf->getString("hash", "md5");
 407
 408                 // The GnuTLS manual states that the gnutls_set_default_priority()
 409                 // call we used previously when initializing the session is the same
 410                 // as setting the "NORMAL" priority string.
 411                 // Thus if the setting below is not in the config we will behave exactly
 412                 // the same as before, when the priority setting wasn't available.
 413                 std::string priorities = Conf->getString("priority", "NORMAL");
 414
 415                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 416                         dh_bits = 1024;
 417
 418                 if (hashname == "md5")
 419                         hash = GNUTLS_DIG_MD5;
 420                 else if (hashname == "sha1")
 421                         hash = GNUTLS_DIG_SHA1;
 422                 else
 423                         throw ModuleException("Unknown hash type " + hashname);
 424
 425
 426                 int ret;
 427
 428                 gnutls_certificate_credentials_t& x509_cred = config->x509_cred;
 429
 430                 ret = gnutls_certificate_allocate_credentials(&x509_cred);
 431                 if (ret < 0)
 432                 {
 433                         // Set to NULL because we can't be sure what value is in it and we must not try to
 434                         // deallocate it in case of an error
 435                         x509_cred = NULL;
 436                         throw ModuleException("Failed to allocate certificate credentials: " + std::string(gnutls_strerror(ret)));
 437                 }
 438
 439                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 440                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));
 441
 442                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 443                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
 444
 445                 FileReader reader;
 446
 447                 reader.LoadFile(certfile);
 448                 std::string cert_string = reader.Contents();
 449                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), static_cast<unsigned int>(cert_string.length()) };
 450
 451                 reader.LoadFile(keyfile);
 452                 std::string key_string = reader.Contents();
 453                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), static_cast<unsigned int>(key_string.length()) };
 454
 455                 std::vector<gnutls_x509_crt_t>& x509_certs = config->x509_certs;
 456
 457                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 458                 unsigned int certcount = 3;
 459                 x509_certs.resize(certcount);
 460                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 461                 if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 462                 {
 463                         // 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
 464                         x509_certs.resize(certcount);
 465                         ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 466                 }
 467
 468                 if (ret <= 0)
 469                 {
 470                         // clear the vector so we won't call gnutls_x509_crt_deinit() on the (uninited) certs later
 471                         x509_certs.clear();
 472                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + ((ret < 0) ? (std::string(gnutls_strerror(ret))) : "No certs could be read"));
 473                 }
 474                 x509_certs.resize(ret);
 475
 476                 gnutls_x509_privkey_t& x509_key = config->x509_key;
 477                 if (gnutls_x509_privkey_init(&x509_key) < 0)
 478                 {
 479                         // Make sure the destructor does not try to deallocate this, see above
 480                         x509_key = NULL;
 481                         throw ModuleException("Unable to initialize private key");
 482                 }
 483
 484                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 485                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 486
 487                 if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 488                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 489
 490                 #ifdef GNUTLS_NEW_PRIO_API
 491                 // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 492                 // If the user did not supply anything then the string is already set to "NORMAL"
 493                 const char* priocstr = priorities.c_str();
 494                 const char* prioerror;
 495
 496                 gnutls_priority_t& priority = config->priority;
 497                 if ((ret = gnutls_priority_init(&priority, priocstr, &prioerror)) < 0)
 498                 {
 499                         // gnutls did not understand the user supplied string, log and fall back to the default priorities
 500                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: 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));
 501                         gnutls_priority_init(&priority, "NORMAL", NULL);
 502                 }
 503
 504                 #else
 505                 if (priorities != "NORMAL")
 506                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: 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.");
 507                 #endif
 508
 509                 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
 510                 gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
 511                 #else
 512                 gnutls_certificate_set_retrieve_function (x509_cred, cert_callback);
 513                 #endif
 514
 515                 gnutls_dh_params_t& dh_params = config->dh_params;
 516                 ret = gnutls_dh_params_init(&dh_params);
 517                 if (ret < 0)
 518                 {
 519                         // Make sure the destructor does not try to deallocate this, see above
 520                         dh_params = NULL;
 521                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 522                         return;
 523                 }
 524
 525                 std::string dhfile = Conf->getString("dhfile");
 526                 if (!dhfile.empty())
 527                 {
 528                         // Try to load DH params from file
 529                         reader.LoadFile(dhfile);
 530                         std::string dhstring = reader.Contents();
 531                         gnutls_datum_t dh_datum = { (unsigned char*)dhstring.data(), static_cast<unsigned int>(dhstring.length()) };
 532
 533                         if ((ret = gnutls_dh_params_import_pkcs3(dh_params, &dh_datum, GNUTLS_X509_FMT_PEM)) < 0)
 534                         {
 535                                 // File unreadable or GnuTLS was unhappy with the contents, generate the DH primes now
 536                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Generating DH parameters because I failed to load them from file '%s': %s", dhfile.c_str(), gnutls_strerror(ret));
 537                                 GenerateDHParams(dh_params);
 538                         }
 539                 }
 540                 else
 541                 {
 542                         GenerateDHParams(dh_params);
 543                 }
 544
 545                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 546         }
 547
 548         void GenerateDHParams(gnutls_dh_params_t dh_params)
 549         {
 550                 // Generate Diffie Hellman parameters - for use with DHE
 551                 // kx algorithms. These should be discarded and regenerated
 552                 // once a day, once a week or once a month. Depending on the
 553                 // security requirements.
 554
 555                 int ret;
 556
 557                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 558                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 559         }
 560
 561         ~ModuleSSLGnuTLS()
 562         {
 563                 currconf = NULL;
 564
 565                 gnutls_global_deinit();
 566                 delete[] sessions;
 567                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 568         }
 569
 570         void OnCleanup(int target_type, void* item)
 571         {
 572                 if(target_type == TYPE_USER)
 573                 {
 574                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 575
 576                         if (user && user->eh.GetIOHook() == this)
 577                         {
 578                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 579                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 580                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 581                         }
 582                 }
 583         }
 584
 585         Version GetVersion()
 586         {
 587                 return Version("Provides SSL support for clients", VF_VENDOR);
 588         }
 589
 590
 591         void On005Numeric(std::string &output)
 592         {
 593                 if (!sslports.empty())
 594                         output.append(" SSL=" + sslports);
 595                 if (starttls.enabled)
 596                         output.append(" STARTTLS");
 597         }
 598
 599         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 600         {
 601                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 602                 {
 603                         /* Hook the user with our module */
 604                         user->AddIOHook(this);
 605                 }
 606         }
 607
 608         void OnRequest(Request& request)
 609         {
 610                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 611                 {
 612                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 613                         int fd = req.sock->GetFd();
 614                         issl_session* session = &sessions[fd];
 615
 616                         req.cert = session->cert;
 617                 }
 618                 else if (!strcmp("GET_RAW_SSL_SESSION", request.id))
 619                 {
 620                         SSLRawSessionRequest& req = static_cast<SSLRawSessionRequest&>(request);
 621                         if ((req.fd >= 0) && (req.fd < ServerInstance->SE->GetMaxFds()))
 622                                 req.data = reinterpret_cast<void*>(sessions[req.fd].sess);
 623                 }
 624         }
 625
 626         void InitSession(StreamSocket* user, bool me_server)
 627         {
 628                 issl_session* session = &sessions[user->GetFd()];
 629
 630                 gnutls_init(&session->sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 631                 session->socket = user;
 632                 session->config = currconf;
 633
 634                 #ifdef GNUTLS_NEW_PRIO_API
 635                 gnutls_priority_set(session->sess, currconf->priority);
 636                 #else
 637                 gnutls_set_default_priority(session->sess);
 638                 #endif
 639                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, currconf->x509_cred);
 640                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 641                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(session));
 642                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 643                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 644
 645                 if (me_server)
 646                         gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 647
 648                 Handshake(session, user);
 649         }
 650
 651         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 652         {
 653                 issl_session* session = &sessions[user->GetFd()];
 654
 655                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 656                 if (session->sess)
 657                         return;
 658
 659                 InitSession(user, true);
 660         }
 661
 662         void OnStreamSocketConnect(StreamSocket* user)
 663         {
 664                 InitSession(user, false);
 665         }
 666
 667         void OnStreamSocketClose(StreamSocket* user)
 668         {
 669                 CloseSession(&sessions[user->GetFd()]);
 670         }
 671
 672         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 673         {
 674                 issl_session* session = &sessions[user->GetFd()];
 675
 676                 if (!session->sess)
 677                 {
 678                         CloseSession(session);
 679                         user->SetError("No SSL session");
 680                         return -1;
 681                 }
 682
 683                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 684                 {
 685                         // The handshake isn't finished, try to finish it.
 686
 687                         if(!Handshake(session, user))
 688                         {
 689                                 if (session->status != ISSL_CLOSING)
 690                                         return 0;
 691                                 return -1;
 692                         }
 693                 }
 694
 695                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 696
 697                 if (session->status == ISSL_HANDSHAKEN)
 698                 {
 699                         char* buffer = ServerInstance->GetReadBuffer();
 700                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 701                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 702                         if (ret > 0)
 703                         {
 704                                 recvq.append(buffer, ret);
 705                                 return 1;
 706                         }
 707                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 708                         {
 709                                 return 0;
 710                         }
 711                         else if (ret == 0)
 712                         {
 713                                 user->SetError("Connection closed");
 714                                 CloseSession(session);
 715                                 return -1;
 716                         }
 717                         else
 718                         {
 719                                 user->SetError(gnutls_strerror(ret));
 720                                 CloseSession(session);
 721                                 return -1;
 722                         }
 723                 }
 724                 else if (session->status == ISSL_CLOSING)
 725                         return -1;
 726
 727                 return 0;
 728         }
 729
 730         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 731         {
 732                 issl_session* session = &sessions[user->GetFd()];
 733
 734                 if (!session->sess)
 735                 {
 736                         CloseSession(session);
 737                         user->SetError("No SSL session");
 738                         return -1;
 739                 }
 740
 741                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 742                 {
 743                         // The handshake isn't finished, try to finish it.
 744                         Handshake(session, user);
 745                         if (session->status != ISSL_CLOSING)
 746                                 return 0;
 747                         return -1;
 748                 }
 749
 750                 int ret = 0;
 751
 752                 if (session->status == ISSL_HANDSHAKEN)
 753                 {
 754                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 755
 756                         if (ret == (int)sendq.length())
 757                         {
 758                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 759                                 return 1;
 760                         }
 761                         else if (ret > 0)
 762                         {
 763                                 sendq = sendq.substr(ret);
 764                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 765                                 return 0;
 766                         }
 767                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 768                         {
 769                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 770                                 return 0;
 771                         }
 772                         else // (ret < 0)
 773                         {
 774                                 user->SetError(gnutls_strerror(ret));
 775                                 CloseSession(session);
 776                                 return -1;
 777                         }
 778                 }
 779
 780                 return 0;
 781         }
 782
 783         bool Handshake(issl_session* session, StreamSocket* user)
 784         {
 785                 int ret = gnutls_handshake(session->sess);
 786
 787                 if (ret < 0)
 788                 {
 789                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 790                         {
 791                                 // Handshake needs resuming later, read() or write() would have blocked.
 792
 793                                 if(gnutls_record_get_direction(session->sess) == 0)
 794                                 {
 795                                         // gnutls_handshake() wants to read() again.
 796                                         session->status = ISSL_HANDSHAKING_READ;
 797                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 798                                 }
 799                                 else
 800                                 {
 801                                         // gnutls_handshake() wants to write() again.
 802                                         session->status = ISSL_HANDSHAKING_WRITE;
 803                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 804                                 }
 805                         }
 806                         else
 807                         {
 808                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 809                                 CloseSession(session);
 810                                 session->status = ISSL_CLOSING;
 811                         }
 812
 813                         return false;
 814                 }
 815                 else
 816                 {
 817                         // Change the seesion state
 818                         session->status = ISSL_HANDSHAKEN;
 819
 820                         VerifyCertificate(session,user);
 821
 822                         // Finish writing, if any left
 823                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 824
 825                         return true;
 826                 }
 827         }
 828
 829         void OnUserConnect(LocalUser* user)
 830         {
 831                 if (user->eh.GetIOHook() == this)
 832                 {
 833                         if (sessions[user->eh.GetFd()].sess)
 834                         {
 835                                 const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
 836                                 std::string cipher = UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 837                                 cipher.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 838                                 cipher.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess))));
 839
 840                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 841                                 if (cert->fingerprint.empty())
 842                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 843                                 else
 844                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 845                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 846                         }
 847                 }
 848         }
 849
 850         void CloseSession(issl_session* session)
 851         {
 852                 if (session->sess)
 853                 {
 854                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 855                         gnutls_deinit(session->sess);
 856                 }
 857                 session->socket = NULL;
 858                 session->sess = NULL;
 859                 session->cert = NULL;
 860                 session->status = ISSL_NONE;
 861                 session->config = NULL;
 862         }
 863
 864         void VerifyCertificate(issl_session* session, StreamSocket* user)
 865         {
 866                 if (!session->sess || !user)
 867                         return;
 868
 869                 unsigned int status;
 870                 const gnutls_datum_t* cert_list;
 871                 int ret;
 872                 unsigned int cert_list_size;
 873                 gnutls_x509_crt_t cert;
 874                 char name[MAXBUF];
 875                 unsigned char digest[MAXBUF];
 876                 size_t digest_size = sizeof(digest);
 877                 size_t name_size = sizeof(name);
 878                 ssl_cert* certinfo = new ssl_cert;
 879                 session->cert = certinfo;
 880
 881                 /* This verification function uses the trusted CAs in the credentials
 882                  * structure. So you must have installed one or more CA certificates.
 883                  */
 884                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 885
 886                 if (ret < 0)
 887                 {
 888                         certinfo->error = std::string(gnutls_strerror(ret));
 889                         return;
 890                 }
 891
 892                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 893                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 894                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 895                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 896
 897                 /* Up to here the process is the same for X.509 certificates and
 898                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 899                  * be easily extended to work with openpgp keys as well.
 900                  */
 901                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 902                 {
 903                         certinfo->error = "No X509 keys sent";
 904                         return;
 905                 }
 906
 907                 ret = gnutls_x509_crt_init(&cert);
 908                 if (ret < 0)
 909                 {
 910                         certinfo->error = gnutls_strerror(ret);
 911                         return;
 912                 }
 913
 914                 cert_list_size = 0;
 915                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 916                 if (cert_list == NULL)
 917                 {
 918                         certinfo->error = "No certificate was found";
 919                         goto info_done_dealloc;
 920                 }
 921
 922                 /* This is not a real world example, since we only check the first
 923                  * certificate in the given chain.
 924                  */
 925
 926                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 927                 if (ret < 0)
 928                 {
 929                         certinfo->error = gnutls_strerror(ret);
 930                         goto info_done_dealloc;
 931                 }
 932
 933                 if (gnutls_x509_crt_get_dn(cert, name, &name_size) == 0)
 934                 {
 935                         std::string& dn = certinfo->dn;
 936                         dn = name;
 937                         // Make sure there are no chars in the string that we consider invalid
 938                         if (dn.find_first_of("\r\n") != std::string::npos)
 939                                 dn.clear();
 940                 }
 941
 942                 name_size = sizeof(name);
 943                 if (gnutls_x509_crt_get_issuer_dn(cert, name, &name_size) == 0)
 944                 {
 945                         std::string& issuer = certinfo->issuer;
 946                         issuer = name;
 947                         if (issuer.find_first_of("\r\n") != std::string::npos)
 948                                 issuer.clear();
 949                 }
 950
 951                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 952                 {
 953                         certinfo->error = gnutls_strerror(ret);
 954                 }
 955                 else
 956                 {
 957                         certinfo->fingerprint = irc::hex(digest, digest_size);
 958                 }
 959
 960                 /* Beware here we do not check for errors.
 961                  */
 962                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 963                 {
 964                         certinfo->error = "Not activated, or expired certificate";
 965                 }
 966
 967 info_done_dealloc:
 968                 gnutls_x509_crt_deinit(cert);
 969         }
 970
 971         void OnEvent(Event& ev)
 972         {
 973                 if (starttls.enabled)
 974                         capHandler.HandleEvent(ev);
 975         }
 976 };
 977
 978 MODULE_INIT(ModuleSSLGnuTLS)