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