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 <gnutls/gnutls.h>
  26 #include <gnutls/x509.h>
  27 #include "modules/ssl.h"
  28 #include <memory>
  29
  30 #if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 9) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 9 && GNUTLS_VERSION_PATCH >= 8))
  31 #define GNUTLS_HAS_MAC_GET_ID
  32 #include <gnutls/crypto.h>
  33 #endif
  34
  35 #if (GNUTLS_VERSION_MAJOR > 2 || GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 12)
  36 # define GNUTLS_HAS_RND
  37 #else
  38 # include <gcrypt.h>
  39 #endif
  40
  41 #ifdef _WIN32
  42 # pragma comment(lib, "libgnutls.lib")
  43 # pragma comment(lib, "libgcrypt.lib")
  44 # pragma comment(lib, "libgpg-error.lib")
  45 # pragma comment(lib, "user32.lib")
  46 # pragma comment(lib, "advapi32.lib")
  47 # pragma comment(lib, "libgcc.lib")
  48 # pragma comment(lib, "libmingwex.lib")
  49 # pragma comment(lib, "gdi32.lib")
  50 #endif
  51
  52 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") eval("print `libgcrypt-config --cflags | tr -d \r` if `pkg-config --modversion gnutls 2>/dev/null | tr -d \r` lt '2.12'") -Wno-pedantic */
  53 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") eval("print `libgcrypt-config --libs | tr -d \r` if `pkg-config --modversion gnutls 2>/dev/null | tr -d \r` lt '2.12'") */
  54
  55 #ifndef GNUTLS_VERSION_MAJOR
  56 #define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
  57 #define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
  58 #define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
  59 #endif
  60
  61 // These don't exist in older GnuTLS versions
  62 #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))
  63 #define GNUTLS_NEW_PRIO_API
  64 #endif
  65
  66 #if(GNUTLS_VERSION_MAJOR < 2)
  67 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  68 typedef gnutls_dh_params_t gnutls_dh_params;
  69 #endif
  70
  71 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  72
  73 #if (GNUTLS_VERSION_MAJOR > 2 || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR >= 12))
  74 #define GNUTLS_NEW_CERT_CALLBACK_API
  75 typedef gnutls_retr2_st cert_cb_last_param_type;
  76 #else
  77 typedef gnutls_retr_st cert_cb_last_param_type;
  78 #endif
  79
  80 class RandGen : public HandlerBase2<void, char*, size_t>
  81 {
  82  public:
  83         void Call(char* buffer, size_t len)
  84         {
  85 #ifdef GNUTLS_HAS_RND
  86                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
  87 #else
  88                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  89 #endif
  90         }
  91 };
  92
  93 namespace GnuTLS
  94 {
  95         class Init
  96         {
  97          public:
  98                 Init() { gnutls_global_init(); }
  99                 ~Init() { gnutls_global_deinit(); }
 100         };
 101
 102         class Exception : public ModuleException
 103         {
 104          public:
 105                 Exception(const std::string& reason)
 106                         : ModuleException(reason) { }
 107         };
 108
 109         void ThrowOnError(int errcode, const char* msg)
 110         {
 111                 if (errcode < 0)
 112                 {
 113                         std::string reason = msg;
 114                         reason.append(" :").append(gnutls_strerror(errcode));
 115                         throw Exception(reason);
 116                 }
 117         }
 118
 119         /** Used to create a gnutls_datum_t* from a std::string
 120          */
 121         class Datum
 122         {
 123                 gnutls_datum_t datum;
 124
 125          public:
 126                 Datum(const std::string& dat)
 127                 {
 128                         datum.data = (unsigned char*)dat.data();
 129                         datum.size = static_cast<unsigned int>(dat.length());
 130                 }
 131
 132                 const gnutls_datum_t* get() const { return &datum; }
 133         };
 134
 135         class Hash
 136         {
 137                 gnutls_digest_algorithm_t hash;
 138
 139          public:
 140                 // Nothing to deallocate, constructor may throw freely
 141                 Hash(const std::string& hashname)
 142                 {
 143                         // As older versions of gnutls can't do this, let's disable it where needed.
 144 #ifdef GNUTLS_HAS_MAC_GET_ID
 145                         // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 146                         // There is no gnutls_dig_get_id() at the moment, but it may come later
 147                         hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 148                         if (hash == GNUTLS_DIG_UNKNOWN)
 149                                 throw Exception("Unknown hash type " + hashname);
 150
 151                         // Check if the user is giving us something that is a valid MAC but not digest
 152                         gnutls_hash_hd_t is_digest;
 153                         if (gnutls_hash_init(&is_digest, hash) < 0)
 154                                 throw Exception("Unknown hash type " + hashname);
 155                         gnutls_hash_deinit(is_digest, NULL);
 156 #else
 157                         if (hashname == "md5")
 158                                 hash = GNUTLS_DIG_MD5;
 159                         else if (hashname == "sha1")
 160                                 hash = GNUTLS_DIG_SHA1;
 161                         else
 162                                 throw Exception("Unknown hash type " + hashname);
 163 #endif
 164                 }
 165
 166                 gnutls_digest_algorithm_t get() const { return hash; }
 167         };
 168
 169         class DHParams
 170         {
 171                 gnutls_dh_params_t dh_params;
 172
 173                 DHParams()
 174                 {
 175                         ThrowOnError(gnutls_dh_params_init(&dh_params), "gnutls_dh_params_init() failed");
 176                 }
 177
 178          public:
 179                 /** Import */
 180                 static std::auto_ptr<DHParams> Import(const std::string& dhstr)
 181                 {
 182                         std::auto_ptr<DHParams> dh(new DHParams);
 183                         int ret = gnutls_dh_params_import_pkcs3(dh->dh_params, Datum(dhstr).get(), GNUTLS_X509_FMT_PEM);
 184                         ThrowOnError(ret, "Unable to import DH params");
 185                         return dh;
 186                 }
 187
 188                 /** Generate */
 189                 static std::auto_ptr<DHParams> Generate(unsigned int bits)
 190                 {
 191                         std::auto_ptr<DHParams> dh(new DHParams);
 192                         ThrowOnError(gnutls_dh_params_generate2(dh->dh_params, bits), "Unable to generate DH params");
 193                         return dh;
 194                 }
 195
 196                 ~DHParams()
 197                 {
 198                         gnutls_dh_params_deinit(dh_params);
 199                 }
 200
 201                 const gnutls_dh_params_t& get() const { return dh_params; }
 202         };
 203
 204         class X509Key
 205         {
 206                 /** Ensure that the key is deinited in case the constructor of X509Key throws
 207                  */
 208                 class RAIIKey
 209                 {
 210                  public:
 211                         gnutls_x509_privkey_t key;
 212
 213                         RAIIKey()
 214                         {
 215                                 ThrowOnError(gnutls_x509_privkey_init(&key), "gnutls_x509_privkey_init() failed");
 216                         }
 217
 218                         ~RAIIKey()
 219                         {
 220                                 gnutls_x509_privkey_deinit(key);
 221                         }
 222                 } key;
 223
 224          public:
 225                 /** Import */
 226                 X509Key(const std::string& keystr)
 227                 {
 228                         int ret = gnutls_x509_privkey_import(key.key, Datum(keystr).get(), GNUTLS_X509_FMT_PEM);
 229                         ThrowOnError(ret, "Unable to import private key");
 230                 }
 231
 232                 gnutls_x509_privkey_t& get() { return key.key; }
 233         };
 234
 235         class X509CertList
 236         {
 237                 std::vector<gnutls_x509_crt_t> certs;
 238
 239          public:
 240                 /** Import */
 241                 X509CertList(const std::string& certstr)
 242                 {
 243                         unsigned int certcount = 3;
 244                         certs.resize(certcount);
 245                         Datum datum(certstr);
 246
 247                         int ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 248                         if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 249                         {
 250                                 // the buffer wasn't big enough to hold all certs but gnutls changed certcount to the number of available certs,
 251                                 // try again with a bigger buffer
 252                                 certs.resize(certcount);
 253                                 ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 254                         }
 255
 256                         ThrowOnError(ret, "Unable to load certificates");
 257
 258                         // Resize the vector to the actual number of certs because we rely on its size being correct
 259                         // when deallocating the certs
 260                         certs.resize(certcount);
 261                 }
 262
 263                 ~X509CertList()
 264                 {
 265                         for (std::vector<gnutls_x509_crt_t>::iterator i = certs.begin(); i != certs.end(); ++i)
 266                                 gnutls_x509_crt_deinit(*i);
 267                 }
 268
 269                 gnutls_x509_crt_t* raw() { return &certs[0]; }
 270                 unsigned int size() const { return certs.size(); }
 271         };
 272
 273         class X509CRL : public refcountbase
 274         {
 275                 class RAIICRL
 276                 {
 277                  public:
 278                         gnutls_x509_crl_t crl;
 279
 280                         RAIICRL()
 281                         {
 282                                 ThrowOnError(gnutls_x509_crl_init(&crl), "gnutls_x509_crl_init() failed");
 283                         }
 284
 285                         ~RAIICRL()
 286                         {
 287                                 gnutls_x509_crl_deinit(crl);
 288                         }
 289                 } crl;
 290
 291          public:
 292                 /** Import */
 293                 X509CRL(const std::string& crlstr)
 294                 {
 295                         int ret = gnutls_x509_crl_import(get(), Datum(crlstr).get(), GNUTLS_X509_FMT_PEM);
 296                         ThrowOnError(ret, "Unable to load certificate revocation list");
 297                 }
 298
 299                 gnutls_x509_crl_t& get() { return crl.crl; }
 300         };
 301
 302 #ifdef GNUTLS_NEW_PRIO_API
 303         class Priority
 304         {
 305                 gnutls_priority_t priority;
 306
 307          public:
 308                 Priority(const std::string& priorities)
 309                 {
 310                         // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 311                         // If the user did not supply anything then the string is already set to "NORMAL"
 312                         const char* priocstr = priorities.c_str();
 313                         const char* prioerror;
 314
 315                         int ret = gnutls_priority_init(&priority, priocstr, &prioerror);
 316                         if (ret < 0)
 317                         {
 318                                 // gnutls did not understand the user supplied string
 319                                 throw Exception("Unable to initialize priorities to \"" + priorities + "\": " + gnutls_strerror(ret) + " Syntax error at position " + ConvToStr((unsigned int) (prioerror - priocstr)));
 320                         }
 321                 }
 322
 323                 ~Priority()
 324                 {
 325                         gnutls_priority_deinit(priority);
 326                 }
 327
 328                 void SetupSession(gnutls_session_t sess)
 329                 {
 330                         gnutls_priority_set(sess, priority);
 331                 }
 332         };
 333 #else
 334         /** Dummy class, used when gnutls_priority_set() is not available
 335          */
 336         class Priority
 337         {
 338          public:
 339                 Priority(const std::string& priorities)
 340                 {
 341                         if (priorities != "NORMAL")
 342                                 throw Exception("You've set a non-default priority string, but GnuTLS lacks support for it");
 343                 }
 344
 345                 static void SetupSession(gnutls_session_t sess)
 346                 {
 347                         // Always set the default priorities
 348                         gnutls_set_default_priority(sess);
 349                 }
 350         };
 351 #endif
 352
 353         class CertCredentials
 354         {
 355                 /** DH parameters associated with these credentials
 356                  */
 357                 std::auto_ptr<DHParams> dh;
 358
 359          protected:
 360                 gnutls_certificate_credentials_t cred;
 361
 362          public:
 363                 CertCredentials()
 364                 {
 365                         ThrowOnError(gnutls_certificate_allocate_credentials(&cred), "Cannot allocate certificate credentials");
 366                 }
 367
 368                 ~CertCredentials()
 369                 {
 370                         gnutls_certificate_free_credentials(cred);
 371                 }
 372
 373                 /** Associates these credentials with the session
 374                  */
 375                 void SetupSession(gnutls_session_t sess)
 376                 {
 377                         gnutls_credentials_set(sess, GNUTLS_CRD_CERTIFICATE, cred);
 378                 }
 379
 380                 /** Set the given DH parameters to be used with these credentials
 381                  */
 382                 void SetDH(std::auto_ptr<DHParams>& DH)
 383                 {
 384                         dh = DH;
 385                         gnutls_certificate_set_dh_params(cred, dh->get());
 386                 }
 387         };
 388
 389         class X509Credentials : public CertCredentials
 390         {
 391                 /** Private key
 392                  */
 393                 X509Key key;
 394
 395                 /** Certificate list, presented to the peer
 396                  */
 397                 X509CertList certs;
 398
 399                 /** Trusted CA, may be NULL
 400                  */
 401                 std::auto_ptr<X509CertList> trustedca;
 402
 403                 /** Certificate revocation list, may be NULL
 404                  */
 405                 std::auto_ptr<X509CRL> crl;
 406
 407                 static int cert_callback(gnutls_session_t session, const gnutls_datum_t* req_ca_rdn, int nreqs, const gnutls_pk_algorithm_t* sign_algos, int sign_algos_length, cert_cb_last_param_type* st);
 408
 409          public:
 410                 X509Credentials(const std::string& certstr, const std::string& keystr)
 411                         : key(keystr)
 412                         , certs(certstr)
 413                 {
 414                         // Throwing is ok here, the destructor of Credentials is called in that case
 415                         int ret = gnutls_certificate_set_x509_key(cred, certs.raw(), certs.size(), key.get());
 416                         ThrowOnError(ret, "Unable to set cert/key pair");
 417
 418 #ifdef GNUTLS_NEW_CERT_CALLBACK_API
 419                         gnutls_certificate_set_retrieve_function(cred, cert_callback);
 420 #else
 421                         gnutls_certificate_client_set_retrieve_function(cred, cert_callback);
 422 #endif
 423                 }
 424
 425                 /** Sets the trusted CA and the certificate revocation list
 426                  * to use when verifying certificates
 427                  */
 428                 void SetCA(std::auto_ptr<X509CertList>& certlist, std::auto_ptr<X509CRL>& CRL)
 429                 {
 430                         // Do nothing if certlist is NULL
 431                         if (certlist.get())
 432                         {
 433                                 int ret = gnutls_certificate_set_x509_trust(cred, certlist->raw(), certlist->size());
 434                                 ThrowOnError(ret, "gnutls_certificate_set_x509_trust() failed");
 435
 436                                 if (CRL.get())
 437                                 {
 438                                         ret = gnutls_certificate_set_x509_crl(cred, &CRL->get(), 1);
 439                                         ThrowOnError(ret, "gnutls_certificate_set_x509_crl() failed");
 440                                 }
 441
 442                                 trustedca = certlist;
 443                                 crl = CRL;
 444                         }
 445                 }
 446         };
 447
 448         class Profile : public refcountbase
 449         {
 450                 /** Name of this profile
 451                  */
 452                 const std::string name;
 453
 454                 /** X509 certificate(s) and key
 455                  */
 456                 X509Credentials x509cred;
 457
 458                 /** The minimum length in bits for the DH prime to be accepted as a client
 459                  */
 460                 unsigned int min_dh_bits;
 461
 462                 /** Hashing algorithm to use when generating certificate fingerprints
 463                  */
 464                 Hash hash;
 465
 466                 /** Priorities for ciphers, compression methods, etc.
 467                  */
 468                 Priority priority;
 469
 470                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 471                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 472                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL)
 473                         : name(profilename)
 474                         , x509cred(certstr, keystr)
 475                         , min_dh_bits(mindh)
 476                         , hash(hashstr)
 477                         , priority(priostr)
 478                 {
 479                         x509cred.SetDH(DH);
 480                         x509cred.SetCA(CA, CRL);
 481                 }
 482
 483                 static std::string ReadFile(const std::string& filename)
 484                 {
 485                         FileReader reader(filename);
 486                         std::string ret = reader.GetString();
 487                         if (ret.empty())
 488                                 throw Exception("Cannot read file " + filename);
 489                         return ret;
 490                 }
 491
 492          public:
 493                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 494                 {
 495                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 496                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 497
 498                         std::auto_ptr<DHParams> dh;
 499                         int gendh = tag->getInt("gendh");
 500                         if (gendh)
 501                         {
 502                                 gendh = (gendh < 1024 ? 1024 : gendh);
 503                                 dh = DHParams::Generate(gendh);
 504                         }
 505                         else
 506                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 507
 508                         // Use default priority string if this tag does not specify one
 509                         std::string priostr = tag->getString("priority", "NORMAL");
 510                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 511                         std::string hashstr = tag->getString("hash", "md5");
 512
 513                         // Load trusted CA and revocation list, if set
 514                         std::auto_ptr<X509CertList> ca;
 515                         std::auto_ptr<X509CRL> crl;
 516                         std::string filename = tag->getString("cafile");
 517                         if (!filename.empty())
 518                         {
 519                                 ca.reset(new X509CertList(ReadFile(filename)));
 520
 521                                 filename = tag->getString("crlfile");
 522                                 if (!filename.empty())
 523                                         crl.reset(new X509CRL(ReadFile(filename)));
 524                         }
 525
 526                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl);
 527                 }
 528
 529                 /** Set up the given session with the settings in this profile
 530                  */
 531                 void SetupSession(gnutls_session_t sess)
 532                 {
 533                         priority.SetupSession(sess);
 534                         x509cred.SetupSession(sess);
 535                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 536                 }
 537
 538                 const std::string& GetName() const { return name; }
 539                 X509Credentials& GetX509Credentials() { return x509cred; }
 540                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 541         };
 542 }
 543
 544 class GnuTLSIOHook : public SSLIOHook
 545 {
 546  private:
 547         gnutls_session_t sess;
 548         issl_status status;
 549         reference<GnuTLS::Profile> profile;
 550
 551         void InitSession(StreamSocket* user, bool me_server)
 552         {
 553                 gnutls_init(&sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 554
 555                 profile->SetupSession(sess);
 556                 gnutls_transport_set_ptr(sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 557                 gnutls_transport_set_push_function(sess, gnutls_push_wrapper);
 558                 gnutls_transport_set_pull_function(sess, gnutls_pull_wrapper);
 559
 560                 if (me_server)
 561                         gnutls_certificate_server_set_request(sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 562         }
 563
 564         void CloseSession()
 565         {
 566                 if (this->sess)
 567                 {
 568                         gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 569                         gnutls_deinit(this->sess);
 570                 }
 571                 sess = NULL;
 572                 certificate = NULL;
 573                 status = ISSL_NONE;
 574         }
 575
 576         bool Handshake(StreamSocket* user)
 577         {
 578                 int ret = gnutls_handshake(this->sess);
 579
 580                 if (ret < 0)
 581                 {
 582                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 583                         {
 584                                 // Handshake needs resuming later, read() or write() would have blocked.
 585
 586                                 if (gnutls_record_get_direction(this->sess) == 0)
 587                                 {
 588                                         // gnutls_handshake() wants to read() again.
 589                                         this->status = ISSL_HANDSHAKING_READ;
 590                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 591                                 }
 592                                 else
 593                                 {
 594                                         // gnutls_handshake() wants to write() again.
 595                                         this->status = ISSL_HANDSHAKING_WRITE;
 596                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 597                                 }
 598                         }
 599                         else
 600                         {
 601                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 602                                 CloseSession();
 603                                 this->status = ISSL_CLOSING;
 604                         }
 605
 606                         return false;
 607                 }
 608                 else
 609                 {
 610                         // Change the seesion state
 611                         this->status = ISSL_HANDSHAKEN;
 612
 613                         VerifyCertificate();
 614
 615                         // Finish writing, if any left
 616                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 617
 618                         return true;
 619                 }
 620         }
 621
 622         void VerifyCertificate()
 623         {
 624                 unsigned int certstatus;
 625                 const gnutls_datum_t* cert_list;
 626                 int ret;
 627                 unsigned int cert_list_size;
 628                 gnutls_x509_crt_t cert;
 629                 char str[512];
 630                 unsigned char digest[512];
 631                 size_t digest_size = sizeof(digest);
 632                 size_t name_size = sizeof(str);
 633                 ssl_cert* certinfo = new ssl_cert;
 634                 this->certificate = certinfo;
 635
 636                 /* This verification function uses the trusted CAs in the credentials
 637                  * structure. So you must have installed one or more CA certificates.
 638                  */
 639                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 640
 641                 if (ret < 0)
 642                 {
 643                         certinfo->error = std::string(gnutls_strerror(ret));
 644                         return;
 645                 }
 646
 647                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 648                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 649                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 650                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 651
 652                 /* Up to here the process is the same for X.509 certificates and
 653                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 654                  * be easily extended to work with openpgp keys as well.
 655                  */
 656                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 657                 {
 658                         certinfo->error = "No X509 keys sent";
 659                         return;
 660                 }
 661
 662                 ret = gnutls_x509_crt_init(&cert);
 663                 if (ret < 0)
 664                 {
 665                         certinfo->error = gnutls_strerror(ret);
 666                         return;
 667                 }
 668
 669                 cert_list_size = 0;
 670                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 671                 if (cert_list == NULL)
 672                 {
 673                         certinfo->error = "No certificate was found";
 674                         goto info_done_dealloc;
 675                 }
 676
 677                 /* This is not a real world example, since we only check the first
 678                  * certificate in the given chain.
 679                  */
 680
 681                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 682                 if (ret < 0)
 683                 {
 684                         certinfo->error = gnutls_strerror(ret);
 685                         goto info_done_dealloc;
 686                 }
 687
 688                 gnutls_x509_crt_get_dn(cert, str, &name_size);
 689                 certinfo->dn = str;
 690
 691                 gnutls_x509_crt_get_issuer_dn(cert, str, &name_size);
 692                 certinfo->issuer = str;
 693
 694                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 695                 {
 696                         certinfo->error = gnutls_strerror(ret);
 697                 }
 698                 else
 699                 {
 700                         certinfo->fingerprint = BinToHex(digest, digest_size);
 701                 }
 702
 703                 /* Beware here we do not check for errors.
 704                  */
 705                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 706                 {
 707                         certinfo->error = "Not activated, or expired certificate";
 708                 }
 709
 710 info_done_dealloc:
 711                 gnutls_x509_crt_deinit(cert);
 712         }
 713
 714         static const char* UnknownIfNULL(const char* str)
 715         {
 716                 return str ? str : "UNKNOWN";
 717         }
 718
 719         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 720         {
 721                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 722 #ifdef _WIN32
 723                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 724 #endif
 725
 726                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 727                 {
 728 #ifdef _WIN32
 729                         gnutls_transport_set_errno(session->sess, EAGAIN);
 730 #else
 731                         errno = EAGAIN;
 732 #endif
 733                         return -1;
 734                 }
 735
 736                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 737
 738 #ifdef _WIN32
 739                 if (rv < 0)
 740                 {
 741                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 742                          * and then set errno appropriately.
 743                          * The gnutls library may also have a different errno variable than us, see
 744                          * gnutls_transport_set_errno(3).
 745                          */
 746                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 747                 }
 748 #endif
 749
 750                 if (rv < (int)size)
 751                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 752                 return rv;
 753         }
 754
 755         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 756         {
 757                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 758 #ifdef _WIN32
 759                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 760 #endif
 761
 762                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 763                 {
 764 #ifdef _WIN32
 765                         gnutls_transport_set_errno(session->sess, EAGAIN);
 766 #else
 767                         errno = EAGAIN;
 768 #endif
 769                         return -1;
 770                 }
 771
 772                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 773
 774 #ifdef _WIN32
 775                 if (rv < 0)
 776                 {
 777                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 778                          * and then set errno appropriately.
 779                          * The gnutls library may also have a different errno variable than us, see
 780                          * gnutls_transport_set_errno(3).
 781                          */
 782                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 783                 }
 784 #endif
 785
 786                 if (rv < (int)size)
 787                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 788                 return rv;
 789         }
 790
 791  public:
 792         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool outbound, const reference<GnuTLS::Profile>& sslprofile)
 793                 : SSLIOHook(hookprov)
 794                 , sess(NULL)
 795                 , status(ISSL_NONE)
 796                 , profile(sslprofile)
 797         {
 798                 InitSession(sock, outbound);
 799                 sock->AddIOHook(this);
 800                 Handshake(sock);
 801         }
 802
 803         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 804         {
 805                 CloseSession();
 806         }
 807
 808         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 809         {
 810                 if (!this->sess)
 811                 {
 812                         CloseSession();
 813                         user->SetError("No SSL session");
 814                         return -1;
 815                 }
 816
 817                 if (this->status == ISSL_HANDSHAKING_READ || this->status == ISSL_HANDSHAKING_WRITE)
 818                 {
 819                         // The handshake isn't finished, try to finish it.
 820
 821                         if (!Handshake(user))
 822                         {
 823                                 if (this->status != ISSL_CLOSING)
 824                                         return 0;
 825                                 return -1;
 826                         }
 827                 }
 828
 829                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 830
 831                 if (this->status == ISSL_HANDSHAKEN)
 832                 {
 833                         char* buffer = ServerInstance->GetReadBuffer();
 834                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 835                         int ret = gnutls_record_recv(this->sess, buffer, bufsiz);
 836                         if (ret > 0)
 837                         {
 838                                 recvq.append(buffer, ret);
 839                                 return 1;
 840                         }
 841                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 842                         {
 843                                 return 0;
 844                         }
 845                         else if (ret == 0)
 846                         {
 847                                 user->SetError("Connection closed");
 848                                 CloseSession();
 849                                 return -1;
 850                         }
 851                         else
 852                         {
 853                                 user->SetError(gnutls_strerror(ret));
 854                                 CloseSession();
 855                                 return -1;
 856                         }
 857                 }
 858                 else if (this->status == ISSL_CLOSING)
 859                         return -1;
 860
 861                 return 0;
 862         }
 863
 864         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 865         {
 866                 if (!this->sess)
 867                 {
 868                         CloseSession();
 869                         user->SetError("No SSL session");
 870                         return -1;
 871                 }
 872
 873                 if (this->status == ISSL_HANDSHAKING_WRITE || this->status == ISSL_HANDSHAKING_READ)
 874                 {
 875                         // The handshake isn't finished, try to finish it.
 876                         Handshake(user);
 877                         if (this->status != ISSL_CLOSING)
 878                                 return 0;
 879                         return -1;
 880                 }
 881
 882                 int ret = 0;
 883
 884                 if (this->status == ISSL_HANDSHAKEN)
 885                 {
 886                         ret = gnutls_record_send(this->sess, sendq.data(), sendq.length());
 887
 888                         if (ret == (int)sendq.length())
 889                         {
 890                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 891                                 return 1;
 892                         }
 893                         else if (ret > 0)
 894                         {
 895                                 sendq = sendq.substr(ret);
 896                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 897                                 return 0;
 898                         }
 899                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 900                         {
 901                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 902                                 return 0;
 903                         }
 904                         else // (ret < 0)
 905                         {
 906                                 user->SetError(gnutls_strerror(ret));
 907                                 CloseSession();
 908                                 return -1;
 909                         }
 910                 }
 911
 912                 return 0;
 913         }
 914
 915         void TellCiphersAndFingerprint(LocalUser* user)
 916         {
 917                 if (sess)
 918                 {
 919                         std::string text = "*** You are connected using SSL cipher '";
 920
 921                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 922                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 923                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 924
 925                         if (!certificate->fingerprint.empty())
 926                                 text += " and your SSL fingerprint is " + certificate->fingerprint;
 927
 928                         user->WriteNotice(text);
 929                 }
 930         }
 931
 932         GnuTLS::Profile* GetProfile() { return profile; }
 933 };
 934
 935 int GnuTLS::X509Credentials::cert_callback(gnutls_session_t sess, const gnutls_datum_t* req_ca_rdn, int nreqs, const gnutls_pk_algorithm_t* sign_algos, int sign_algos_length, cert_cb_last_param_type* st)
 936 {
 937 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
 938         st->type = GNUTLS_CRT_X509;
 939 #else
 940         st->cert_type = GNUTLS_CRT_X509;
 941         st->key_type = GNUTLS_PRIVKEY_X509;
 942 #endif
 943         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
 944         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
 945
 946         st->ncerts = cred.certs.size();
 947         st->cert.x509 = cred.certs.raw();
 948         st->key.x509 = cred.key.get();
 949         st->deinit_all = 0;
 950
 951         return 0;
 952 }
 953
 954 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
 955 {
 956         reference<GnuTLS::Profile> profile;
 957
 958  public:
 959         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
 960                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
 961                 , profile(prof)
 962         {
 963                 ServerInstance->Modules->AddService(*this);
 964         }
 965
 966         ~GnuTLSIOHookProvider()
 967         {
 968                 ServerInstance->Modules->DelService(*this);
 969         }
 970
 971         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 972         {
 973                 new GnuTLSIOHook(this, sock, true, profile);
 974         }
 975
 976         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
 977         {
 978                 new GnuTLSIOHook(this, sock, false, profile);
 979         }
 980 };
 981
 982 class ModuleSSLGnuTLS : public Module
 983 {
 984         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
 985
 986         // First member of the class, gets constructed first and destructed last
 987         GnuTLS::Init libinit;
 988         RandGen randhandler;
 989         ProfileList profiles;
 990
 991         void ReadProfiles()
 992         {
 993                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
 994                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
 995                 // avoiding unpleasant situations where no new SSL connections are possible.
 996                 ProfileList newprofiles;
 997
 998                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
 999                 if (tags.first == tags.second)
1000                 {
1001                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1002                         const std::string defname = "gnutls";
1003                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1004                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1005
1006                         try
1007                         {
1008                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1009                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1010                         }
1011                         catch (CoreException& ex)
1012                         {
1013                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1014                         }
1015                 }
1016
1017                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1018                 {
1019                         ConfigTag* tag = i->second;
1020                         if (tag->getString("provider") != "gnutls")
1021                                 continue;
1022
1023                         std::string name = tag->getString("name");
1024                         if (name.empty())
1025                         {
1026                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1027                                 continue;
1028                         }
1029
1030                         reference<GnuTLS::Profile> profile;
1031                         try
1032                         {
1033                                 profile = GnuTLS::Profile::Create(name, tag);
1034                         }
1035                         catch (CoreException& ex)
1036                         {
1037                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1038                         }
1039
1040                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1041                 }
1042
1043                 // New profiles are ok, begin using them
1044                 // Old profiles are deleted when their refcount drops to zero
1045                 profiles.swap(newprofiles);
1046         }
1047
1048  public:
1049         ModuleSSLGnuTLS()
1050         {
1051 #ifndef GNUTLS_HAS_RND
1052                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1053 #endif
1054         }
1055
1056         void init() CXX11_OVERRIDE
1057         {
1058                 ReadProfiles();
1059                 ServerInstance->GenRandom = &randhandler;
1060         }
1061
1062         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1063         {
1064                 if(param != "ssl")
1065                         return;
1066
1067                 try
1068                 {
1069                         ReadProfiles();
1070                 }
1071                 catch (ModuleException& ex)
1072                 {
1073                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1074                 }
1075         }
1076
1077         ~ModuleSSLGnuTLS()
1078         {
1079                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1080         }
1081
1082         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1083         {
1084                 if(target_type == TYPE_USER)
1085                 {
1086                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1087
1088                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1089                         {
1090                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1091                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1092                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1093                         }
1094                 }
1095         }
1096
1097         Version GetVersion() CXX11_OVERRIDE
1098         {
1099                 return Version("Provides SSL support for clients", VF_VENDOR);
1100         }
1101
1102         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1103         {
1104                 IOHook* hook = user->eh.GetIOHook();
1105                 if (hook && hook->prov->creator == this)
1106                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1107         }
1108 };
1109
1110 MODULE_INIT(ModuleSSLGnuTLS)