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 #include <gcrypt.h>
  26 #include <gnutls/gnutls.h>
  27 #include <gnutls/x509.h>
  28 #include "ssl.h"
  29 #include "m_cap.h"
  30
  31 #ifdef _WIN32
  32 # pragma comment(lib, "libgnutls.lib")
  33 # pragma comment(lib, "libgcrypt.lib")
  34 # pragma comment(lib, "libgpg-error.lib")
  35 # pragma comment(lib, "user32.lib")
  36 # pragma comment(lib, "advapi32.lib")
  37 # pragma comment(lib, "libgcc.lib")
  38 # pragma comment(lib, "libmingwex.lib")
  39 # pragma comment(lib, "gdi32.lib")
  40 #endif
  41
  42 /* $ModDesc: Provides SSL support for clients */
  43 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") exec("libgcrypt-config --cflags") */
  44 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") exec("libgcrypt-config --libs") */
  45 /* $NoPedantic */
  46
  47 #ifndef GNUTLS_VERSION_MAJOR
  48 #define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
  49 #define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
  50 #define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
  51 #endif
  52
  53 // These don't exist in older GnuTLS versions
  54 #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))
  55 #define GNUTLS_NEW_PRIO_API
  56 #endif
  57
  58 #if(GNUTLS_VERSION_MAJOR < 2)
  59 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  60 typedef gnutls_dh_params_t gnutls_dh_params;
  61 #endif
  62
  63 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  64
  65 static std::vector<gnutls_x509_crt_t> x509_certs;
  66 static gnutls_x509_privkey_t x509_key;
  67 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
  68 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  69         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
  70
  71         st->type = GNUTLS_CRT_X509;
  72 #else
  73 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  74         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr2_st * st) {
  75         st->cert_type = GNUTLS_CRT_X509;
  76         st->key_type = GNUTLS_PRIVKEY_X509;
  77 #endif
  78         st->ncerts = x509_certs.size();
  79         st->cert.x509 = &x509_certs[0];
  80         st->key.x509 = x509_key;
  81         st->deinit_all = 0;
  82
  83         return 0;
  84 }
  85
  86 class RandGen : public HandlerBase2<void, char*, size_t>
  87 {
  88  public:
  89         RandGen() {}
  90         void Call(char* buffer, size_t len)
  91         {
  92                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  93         }
  94 };
  95
  96 /** Represents an SSL user's extra data
  97  */
  98 class issl_session
  99 {
 100 public:
 101         StreamSocket* socket;
 102         gnutls_session_t sess;
 103         issl_status status;
 104         reference<ssl_cert> cert;
 105
 106         issl_session() : socket(NULL), sess(NULL) {}
 107 };
 108
 109 class CommandStartTLS : public SplitCommand
 110 {
 111  public:
 112         bool enabled;
 113         CommandStartTLS (Module* mod) : SplitCommand(mod, "STARTTLS")
 114         {
 115                 enabled = true;
 116                 works_before_reg = true;
 117         }
 118
 119         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 120         {
 121                 if (!enabled)
 122                 {
 123                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 124                         return CMD_FAILURE;
 125                 }
 126
 127                 if (user->registered == REG_ALL)
 128                 {
 129                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 130                 }
 131                 else
 132                 {
 133                         if (!user->eh.GetIOHook())
 134                         {
 135                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 136                                 /* We need to flush the write buffer prior to adding the IOHook,
 137                                  * otherwise we'll be sending this line inside the SSL session - which
 138                                  * won't start its handshake until the client gets this line. Currently,
 139                                  * we assume the write will not block here; this is usually safe, as
 140                                  * STARTTLS is sent very early on in the registration phase, where the
 141                                  * user hasn't built up much sendq. Handling a blocked write here would
 142                                  * be very annoying.
 143                                  */
 144                                 user->eh.DoWrite();
 145                                 user->eh.AddIOHook(creator);
 146                                 creator->OnStreamSocketAccept(&user->eh, NULL, NULL);
 147                         }
 148                         else
 149                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 150                 }
 151
 152                 return CMD_FAILURE;
 153         }
 154 };
 155
 156 class ModuleSSLGnuTLS : public Module
 157 {
 158         issl_session* sessions;
 159
 160         gnutls_certificate_credentials_t x509_cred;
 161         gnutls_dh_params_t dh_params;
 162         gnutls_digest_algorithm_t hash;
 163         #ifdef GNUTLS_NEW_PRIO_API
 164         gnutls_priority_t priority;
 165         #endif
 166
 167         std::string sslports;
 168         int dh_bits;
 169
 170         bool cred_alloc;
 171         bool dh_alloc;
 172
 173         RandGen randhandler;
 174         CommandStartTLS starttls;
 175
 176         GenericCap capHandler;
 177         ServiceProvider iohook;
 178
 179         inline static const char* UnknownIfNULL(const char* str)
 180         {
 181                 return str ? str : "UNKNOWN";
 182         }
 183
 184         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 185         {
 186                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 187                 if (session->socket->GetEventMask() & FD_READ_WILL_BLOCK)
 188                 {
 189 #ifdef _WIN32
 190                         gnutls_transport_set_errno(session->sess, EAGAIN);
 191 #else
 192                         errno = EAGAIN;
 193 #endif
 194                         return -1;
 195                 }
 196
 197                 int rv = ServerInstance->SE->Recv(session->socket, reinterpret_cast<char *>(buffer), size, 0);
 198
 199 #ifdef _WIN32
 200                 if (rv < 0)
 201                 {
 202                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 203                          * and then set errno appropriately.
 204                          * The gnutls library may also have a different errno variable than us, see
 205                          * gnutls_transport_set_errno(3).
 206                          */
 207                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 208                 }
 209 #endif
 210
 211                 if (rv < (int)size)
 212                         ServerInstance->SE->ChangeEventMask(session->socket, FD_READ_WILL_BLOCK);
 213                 return rv;
 214         }
 215
 216         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 217         {
 218                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 219                 if (session->socket->GetEventMask() & FD_WRITE_WILL_BLOCK)
 220                 {
 221 #ifdef _WIN32
 222                         gnutls_transport_set_errno(session->sess, EAGAIN);
 223 #else
 224                         errno = EAGAIN;
 225 #endif
 226                         return -1;
 227                 }
 228
 229                 int rv = ServerInstance->SE->Send(session->socket, reinterpret_cast<const char *>(buffer), size, 0);
 230
 231 #ifdef _WIN32
 232                 if (rv < 0)
 233                 {
 234                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 235                          * and then set errno appropriately.
 236                          * The gnutls library may also have a different errno variable than us, see
 237                          * gnutls_transport_set_errno(3).
 238                          */
 239                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 240                 }
 241 #endif
 242
 243                 if (rv < (int)size)
 244                         ServerInstance->SE->ChangeEventMask(session->socket, FD_WRITE_WILL_BLOCK);
 245                 return rv;
 246         }
 247
 248  public:
 249
 250         ModuleSSLGnuTLS()
 251                 : starttls(this), capHandler(this, "tls"), iohook(this, "ssl/gnutls", SERVICE_IOHOOK)
 252         {
 253                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 254
 255                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 256
 257                 gnutls_global_init(); // This must be called once in the program
 258                 gnutls_x509_privkey_init(&x509_key);
 259
 260                 #ifdef GNUTLS_NEW_PRIO_API
 261                 // Init this here so it's always initialized, avoids an extra boolean
 262                 gnutls_priority_init(&priority, "NORMAL", NULL);
 263                 #endif
 264
 265                 cred_alloc = false;
 266                 dh_alloc = false;
 267         }
 268
 269         void init()
 270         {
 271                 // Needs the flag as it ignores a plain /rehash
 272                 OnModuleRehash(NULL,"ssl");
 273
 274                 ServerInstance->GenRandom = &randhandler;
 275
 276                 // Void return, guess we assume success
 277                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 278                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 279                         I_OnEvent, I_OnHookIO };
 280                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 281
 282                 ServerInstance->Modules->AddService(iohook);
 283                 ServerInstance->Modules->AddService(starttls);
 284         }
 285
 286         void OnRehash(User* user)
 287         {
 288                 sslports.clear();
 289
 290                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 291                 starttls.enabled = Conf->getBool("starttls", true);
 292
 293                 if (Conf->getBool("showports", true))
 294                 {
 295                         sslports = Conf->getString("advertisedports");
 296                         if (!sslports.empty())
 297                                 return;
 298
 299                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 300                         {
 301                                 ListenSocket* port = ServerInstance->ports[i];
 302                                 if (port->bind_tag->getString("ssl") != "gnutls")
 303                                         continue;
 304
 305                                 const std::string& portid = port->bind_desc;
 306                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 307
 308                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 309                                 {
 310                                         /*
 311                                          * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
 312                                          * the IP:port in ISUPPORT.
 313                                          *
 314                                          * We used to advertise all ports seperated by a ';' char that matched the above criteria,
 315                                          * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
 316                                          * To solve this by default we now only display the first IP:port found and let the user
 317                                          * configure the exact value for the 005 token, if necessary.
 318                                          */
 319                                         sslports = portid;
 320                                         break;
 321                                 }
 322                         }
 323                 }
 324         }
 325
 326         void OnModuleRehash(User* user, const std::string &param)
 327         {
 328                 if(param != "ssl")
 329                         return;
 330
 331                 std::string keyfile;
 332                 std::string certfile;
 333                 std::string cafile;
 334                 std::string crlfile;
 335                 OnRehash(user);
 336
 337                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 338
 339                 cafile = Conf->getString("cafile", CONFIG_PATH "/ca.pem");
 340                 crlfile = Conf->getString("crlfile", CONFIG_PATH "/crl.pem");
 341                 certfile = Conf->getString("certfile", CONFIG_PATH "/cert.pem");
 342                 keyfile = Conf->getString("keyfile", CONFIG_PATH "/key.pem");
 343                 dh_bits = Conf->getInt("dhbits");
 344                 std::string hashname = Conf->getString("hash", "md5");
 345
 346                 // The GnuTLS manual states that the gnutls_set_default_priority()
 347                 // call we used previously when initializing the session is the same
 348                 // as setting the "NORMAL" priority string.
 349                 // Thus if the setting below is not in the config we will behave exactly
 350                 // the same as before, when the priority setting wasn't available.
 351                 std::string priorities = Conf->getString("priority", "NORMAL");
 352
 353                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 354                         dh_bits = 1024;
 355
 356                 if (hashname == "md5")
 357                         hash = GNUTLS_DIG_MD5;
 358                 else if (hashname == "sha1")
 359                         hash = GNUTLS_DIG_SHA1;
 360                 else
 361                         throw ModuleException("Unknown hash type " + hashname);
 362
 363
 364                 int ret;
 365
 366                 if (dh_alloc)
 367                 {
 368                         gnutls_dh_params_deinit(dh_params);
 369                         dh_alloc = false;
 370                         dh_params = NULL;
 371                 }
 372
 373                 if (cred_alloc)
 374                 {
 375                         // Deallocate the old credentials
 376                         gnutls_certificate_free_credentials(x509_cred);
 377
 378                         for(unsigned int i=0; i < x509_certs.size(); i++)
 379                                 gnutls_x509_crt_deinit(x509_certs[i]);
 380                         x509_certs.clear();
 381                 }
 382
 383                 ret = gnutls_certificate_allocate_credentials(&x509_cred);
 384                 cred_alloc = (ret >= 0);
 385                 if (!cred_alloc)
 386                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 387
 388                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 389                         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));
 390
 391                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 392                         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));
 393
 394                 FileReader reader;
 395
 396                 reader.LoadFile(certfile);
 397                 std::string cert_string = reader.Contents();
 398                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), static_cast<unsigned int>(cert_string.length()) };
 399
 400                 reader.LoadFile(keyfile);
 401                 std::string key_string = reader.Contents();
 402                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), static_cast<unsigned int>(key_string.length()) };
 403
 404                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 405                 unsigned int certcount = 3;
 406                 x509_certs.resize(certcount);
 407                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 408                 if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 409                 {
 410                         // 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
 411                         x509_certs.resize(certcount);
 412                         ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 413                 }
 414
 415                 if (ret <= 0)
 416                 {
 417                         // clear the vector so we won't call gnutls_x509_crt_deinit() on the (uninited) certs later
 418                         x509_certs.clear();
 419                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + ((ret < 0) ? (std::string(gnutls_strerror(ret))) : "No certs could be read"));
 420                 }
 421                 x509_certs.resize(ret);
 422
 423                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 424                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 425
 426                 if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 427                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 428
 429                 #ifdef GNUTLS_NEW_PRIO_API
 430                 // It's safe to call this every time as we cannot have this uninitialized, see constructor and below.
 431                 gnutls_priority_deinit(priority);
 432
 433                 // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 434                 // If the user did not supply anything then the string is already set to "NORMAL"
 435                 const char* priocstr = priorities.c_str();
 436                 const char* prioerror;
 437
 438                 if ((ret = gnutls_priority_init(&priority, priocstr, &prioerror)) < 0)
 439                 {
 440                         // gnutls did not understand the user supplied string, log and fall back to the default priorities
 441                         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));
 442                         gnutls_priority_init(&priority, "NORMAL", NULL);
 443                 }
 444
 445                 #else
 446                 if (priorities != "NORMAL")
 447                         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.");
 448                 #endif
 449
 450                 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
 451                 gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
 452                 #else
 453                 gnutls_certificate_set_retrieve_function (x509_cred, cert_callback);
 454                 #endif
 455                 ret = gnutls_dh_params_init(&dh_params);
 456                 dh_alloc = (ret >= 0);
 457                 if (!dh_alloc)
 458                 {
 459                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 460                         return;
 461                 }
 462
 463                 std::string dhfile = Conf->getString("dhfile");
 464                 if (!dhfile.empty())
 465                 {
 466                         // Try to load DH params from file
 467                         reader.LoadFile(dhfile);
 468                         std::string dhstring = reader.Contents();
 469                         gnutls_datum_t dh_datum = { (unsigned char*)dhstring.data(), static_cast<unsigned int>(dhstring.length()) };
 470
 471                         if ((ret = gnutls_dh_params_import_pkcs3(dh_params, &dh_datum, GNUTLS_X509_FMT_PEM)) < 0)
 472                         {
 473                                 // File unreadable or GnuTLS was unhappy with the contents, generate the DH primes now
 474                                 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));
 475                                 GenerateDHParams();
 476                         }
 477                 }
 478                 else
 479                 {
 480                         GenerateDHParams();
 481                 }
 482         }
 483
 484         void GenerateDHParams()
 485         {
 486                 // Generate Diffie Hellman parameters - for use with DHE
 487                 // kx algorithms. These should be discarded and regenerated
 488                 // once a day, once a week or once a month. Depending on the
 489                 // security requirements.
 490
 491                 if (!dh_alloc)
 492                         return;
 493
 494                 int ret;
 495
 496                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 497                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 498         }
 499
 500         ~ModuleSSLGnuTLS()
 501         {
 502                 for(unsigned int i=0; i < x509_certs.size(); i++)
 503                         gnutls_x509_crt_deinit(x509_certs[i]);
 504
 505                 gnutls_x509_privkey_deinit(x509_key);
 506                 #ifdef GNUTLS_NEW_PRIO_API
 507                 gnutls_priority_deinit(priority);
 508                 #endif
 509
 510                 if (dh_alloc)
 511                         gnutls_dh_params_deinit(dh_params);
 512                 if (cred_alloc)
 513                         gnutls_certificate_free_credentials(x509_cred);
 514
 515                 gnutls_global_deinit();
 516                 delete[] sessions;
 517                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 518         }
 519
 520         void OnCleanup(int target_type, void* item)
 521         {
 522                 if(target_type == TYPE_USER)
 523                 {
 524                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 525
 526                         if (user && user->eh.GetIOHook() == this)
 527                         {
 528                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 529                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 530                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 531                         }
 532                 }
 533         }
 534
 535         Version GetVersion()
 536         {
 537                 return Version("Provides SSL support for clients", VF_VENDOR);
 538         }
 539
 540
 541         void On005Numeric(std::string &output)
 542         {
 543                 if (!sslports.empty())
 544                         output.append(" SSL=" + sslports);
 545                 if (starttls.enabled)
 546                         output.append(" STARTTLS");
 547         }
 548
 549         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 550         {
 551                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 552                 {
 553                         /* Hook the user with our module */
 554                         user->AddIOHook(this);
 555                 }
 556         }
 557
 558         void OnRequest(Request& request)
 559         {
 560                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 561                 {
 562                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 563                         int fd = req.sock->GetFd();
 564                         issl_session* session = &sessions[fd];
 565
 566                         req.cert = session->cert;
 567                 }
 568         }
 569
 570         void InitSession(StreamSocket* user, bool me_server)
 571         {
 572                 issl_session* session = &sessions[user->GetFd()];
 573
 574                 gnutls_init(&session->sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 575                 session->socket = user;
 576
 577                 #ifdef GNUTLS_NEW_PRIO_API
 578                 gnutls_priority_set(session->sess, priority);
 579                 #else
 580                 gnutls_set_default_priority(session->sess);
 581                 #endif
 582                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 583                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 584                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(session));
 585                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 586                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 587
 588                 if (me_server)
 589                         gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 590
 591                 Handshake(session, user);
 592         }
 593
 594         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 595         {
 596                 issl_session* session = &sessions[user->GetFd()];
 597
 598                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 599                 if (session->sess)
 600                         return;
 601
 602                 InitSession(user, true);
 603         }
 604
 605         void OnStreamSocketConnect(StreamSocket* user)
 606         {
 607                 InitSession(user, false);
 608         }
 609
 610         void OnStreamSocketClose(StreamSocket* user)
 611         {
 612                 CloseSession(&sessions[user->GetFd()]);
 613         }
 614
 615         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 616         {
 617                 issl_session* session = &sessions[user->GetFd()];
 618
 619                 if (!session->sess)
 620                 {
 621                         CloseSession(session);
 622                         user->SetError("No SSL session");
 623                         return -1;
 624                 }
 625
 626                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 627                 {
 628                         // The handshake isn't finished, try to finish it.
 629
 630                         if(!Handshake(session, user))
 631                         {
 632                                 if (session->status != ISSL_CLOSING)
 633                                         return 0;
 634                                 return -1;
 635                         }
 636                 }
 637
 638                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 639
 640                 if (session->status == ISSL_HANDSHAKEN)
 641                 {
 642                         char* buffer = ServerInstance->GetReadBuffer();
 643                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 644                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 645                         if (ret > 0)
 646                         {
 647                                 recvq.append(buffer, ret);
 648                                 return 1;
 649                         }
 650                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 651                         {
 652                                 return 0;
 653                         }
 654                         else if (ret == 0)
 655                         {
 656                                 user->SetError("Connection closed");
 657                                 CloseSession(session);
 658                                 return -1;
 659                         }
 660                         else
 661                         {
 662                                 user->SetError(gnutls_strerror(ret));
 663                                 CloseSession(session);
 664                                 return -1;
 665                         }
 666                 }
 667                 else if (session->status == ISSL_CLOSING)
 668                         return -1;
 669
 670                 return 0;
 671         }
 672
 673         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 674         {
 675                 issl_session* session = &sessions[user->GetFd()];
 676
 677                 if (!session->sess)
 678                 {
 679                         CloseSession(session);
 680                         user->SetError("No SSL session");
 681                         return -1;
 682                 }
 683
 684                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 685                 {
 686                         // The handshake isn't finished, try to finish it.
 687                         Handshake(session, user);
 688                         if (session->status != ISSL_CLOSING)
 689                                 return 0;
 690                         return -1;
 691                 }
 692
 693                 int ret = 0;
 694
 695                 if (session->status == ISSL_HANDSHAKEN)
 696                 {
 697                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 698
 699                         if (ret == (int)sendq.length())
 700                         {
 701                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 702                                 return 1;
 703                         }
 704                         else if (ret > 0)
 705                         {
 706                                 sendq = sendq.substr(ret);
 707                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 708                                 return 0;
 709                         }
 710                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 711                         {
 712                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 713                                 return 0;
 714                         }
 715                         else // (ret < 0)
 716                         {
 717                                 user->SetError(gnutls_strerror(ret));
 718                                 CloseSession(session);
 719                                 return -1;
 720                         }
 721                 }
 722
 723                 return 0;
 724         }
 725
 726         bool Handshake(issl_session* session, StreamSocket* user)
 727         {
 728                 int ret = gnutls_handshake(session->sess);
 729
 730                 if (ret < 0)
 731                 {
 732                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 733                         {
 734                                 // Handshake needs resuming later, read() or write() would have blocked.
 735
 736                                 if(gnutls_record_get_direction(session->sess) == 0)
 737                                 {
 738                                         // gnutls_handshake() wants to read() again.
 739                                         session->status = ISSL_HANDSHAKING_READ;
 740                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 741                                 }
 742                                 else
 743                                 {
 744                                         // gnutls_handshake() wants to write() again.
 745                                         session->status = ISSL_HANDSHAKING_WRITE;
 746                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 747                                 }
 748                         }
 749                         else
 750                         {
 751                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 752                                 CloseSession(session);
 753                                 session->status = ISSL_CLOSING;
 754                         }
 755
 756                         return false;
 757                 }
 758                 else
 759                 {
 760                         // Change the seesion state
 761                         session->status = ISSL_HANDSHAKEN;
 762
 763                         VerifyCertificate(session,user);
 764
 765                         // Finish writing, if any left
 766                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 767
 768                         return true;
 769                 }
 770         }
 771
 772         void OnUserConnect(LocalUser* user)
 773         {
 774                 if (user->eh.GetIOHook() == this)
 775                 {
 776                         if (sessions[user->eh.GetFd()].sess)
 777                         {
 778                                 const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
 779                                 std::string cipher = UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 780                                 cipher.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 781                                 cipher.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess))));
 782
 783                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 784                                 if (cert->fingerprint.empty())
 785                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 786                                 else
 787                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 788                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 789                         }
 790                 }
 791         }
 792
 793         void CloseSession(issl_session* session)
 794         {
 795                 if (session->sess)
 796                 {
 797                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 798                         gnutls_deinit(session->sess);
 799                 }
 800                 session->socket = NULL;
 801                 session->sess = NULL;
 802                 session->cert = NULL;
 803                 session->status = ISSL_NONE;
 804         }
 805
 806         void VerifyCertificate(issl_session* session, StreamSocket* user)
 807         {
 808                 if (!session->sess || !user)
 809                         return;
 810
 811                 unsigned int status;
 812                 const gnutls_datum_t* cert_list;
 813                 int ret;
 814                 unsigned int cert_list_size;
 815                 gnutls_x509_crt_t cert;
 816                 char name[MAXBUF];
 817                 unsigned char digest[MAXBUF];
 818                 size_t digest_size = sizeof(digest);
 819                 size_t name_size = sizeof(name);
 820                 ssl_cert* certinfo = new ssl_cert;
 821                 session->cert = certinfo;
 822
 823                 /* This verification function uses the trusted CAs in the credentials
 824                  * structure. So you must have installed one or more CA certificates.
 825                  */
 826                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 827
 828                 if (ret < 0)
 829                 {
 830                         certinfo->error = std::string(gnutls_strerror(ret));
 831                         return;
 832                 }
 833
 834                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 835                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 836                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 837                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 838
 839                 /* Up to here the process is the same for X.509 certificates and
 840                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 841                  * be easily extended to work with openpgp keys as well.
 842                  */
 843                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 844                 {
 845                         certinfo->error = "No X509 keys sent";
 846                         return;
 847                 }
 848
 849                 ret = gnutls_x509_crt_init(&cert);
 850                 if (ret < 0)
 851                 {
 852                         certinfo->error = gnutls_strerror(ret);
 853                         return;
 854                 }
 855
 856                 cert_list_size = 0;
 857                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 858                 if (cert_list == NULL)
 859                 {
 860                         certinfo->error = "No certificate was found";
 861                         goto info_done_dealloc;
 862                 }
 863
 864                 /* This is not a real world example, since we only check the first
 865                  * certificate in the given chain.
 866                  */
 867
 868                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 869                 if (ret < 0)
 870                 {
 871                         certinfo->error = gnutls_strerror(ret);
 872                         goto info_done_dealloc;
 873                 }
 874
 875                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 876                 certinfo->dn = name;
 877
 878                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 879                 certinfo->issuer = name;
 880
 881                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 882                 {
 883                         certinfo->error = gnutls_strerror(ret);
 884                 }
 885                 else
 886                 {
 887                         certinfo->fingerprint = irc::hex(digest, digest_size);
 888                 }
 889
 890                 /* Beware here we do not check for errors.
 891                  */
 892                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 893                 {
 894                         certinfo->error = "Not activated, or expired certificate";
 895                 }
 896
 897 info_done_dealloc:
 898                 gnutls_x509_crt_deinit(cert);
 899         }
 900
 901         void OnEvent(Event& ev)
 902         {
 903                 if (starttls.enabled)
 904                         capHandler.HandleEvent(ev);
 905         }
 906 };
 907
 908 MODULE_INIT(ModuleSSLGnuTLS)