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