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 "modules/ssl.h"
  26 #include <memory>
  27
  28 // Fix warnings about the use of commas at end of enumerator lists on C++03.
  29 #if defined __clang__
  30 # pragma clang diagnostic ignored "-Wc++11-extensions"
  31 #elif defined __GNUC__
  32 # pragma GCC diagnostic ignored "-pedantic"
  33 #endif
  34
  35 #include <gnutls/gnutls.h>
  36 #include <gnutls/x509.h>
  37
  38 #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))
  39 #define GNUTLS_HAS_MAC_GET_ID
  40 #include <gnutls/crypto.h>
  41 #endif
  42
  43 #if (GNUTLS_VERSION_MAJOR > 2 || GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 12)
  44 # define GNUTLS_HAS_RND
  45 #else
  46 # include <gcrypt.h>
  47 #endif
  48
  49 #ifdef _WIN32
  50 # pragma comment(lib, "libgnutls-28.lib")
  51 #endif
  52
  53 /* $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'") */
  54 /* $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'") */
  55
  56 #ifndef GNUTLS_VERSION_MAJOR
  57 #define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
  58 #define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
  59 #define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
  60 #endif
  61
  62 // These don't exist in older GnuTLS versions
  63 #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))
  64 #define GNUTLS_NEW_PRIO_API
  65 #endif
  66
  67 #if(GNUTLS_VERSION_MAJOR < 2)
  68 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  69 typedef gnutls_dh_params_t gnutls_dh_params;
  70 #endif
  71
  72 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  73
  74 #if (GNUTLS_VERSION_MAJOR > 2 || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR >= 12))
  75 #define GNUTLS_NEW_CERT_CALLBACK_API
  76 typedef gnutls_retr2_st cert_cb_last_param_type;
  77 #else
  78 typedef gnutls_retr_st cert_cb_last_param_type;
  79 #endif
  80
  81 class RandGen : public HandlerBase2<void, char*, size_t>
  82 {
  83  public:
  84         void Call(char* buffer, size_t len)
  85         {
  86 #ifdef GNUTLS_HAS_RND
  87                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
  88 #else
  89                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  90 #endif
  91         }
  92 };
  93
  94 namespace GnuTLS
  95 {
  96         class Init
  97         {
  98          public:
  99                 Init() { gnutls_global_init(); }
 100                 ~Init() { gnutls_global_deinit(); }
 101         };
 102
 103         class Exception : public ModuleException
 104         {
 105          public:
 106                 Exception(const std::string& reason)
 107                         : ModuleException(reason) { }
 108         };
 109
 110         void ThrowOnError(int errcode, const char* msg)
 111         {
 112                 if (errcode < 0)
 113                 {
 114                         std::string reason = msg;
 115                         reason.append(" :").append(gnutls_strerror(errcode));
 116                         throw Exception(reason);
 117                 }
 118         }
 119
 120         /** Used to create a gnutls_datum_t* from a std::string
 121          */
 122         class Datum
 123         {
 124                 gnutls_datum_t datum;
 125
 126          public:
 127                 Datum(const std::string& dat)
 128                 {
 129                         datum.data = (unsigned char*)dat.data();
 130                         datum.size = static_cast<unsigned int>(dat.length());
 131                 }
 132
 133                 const gnutls_datum_t* get() const { return &datum; }
 134         };
 135
 136         class Hash
 137         {
 138                 gnutls_digest_algorithm_t hash;
 139
 140          public:
 141                 // Nothing to deallocate, constructor may throw freely
 142                 Hash(const std::string& hashname)
 143                 {
 144                         // As older versions of gnutls can't do this, let's disable it where needed.
 145 #ifdef GNUTLS_HAS_MAC_GET_ID
 146                         // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 147                         // There is no gnutls_dig_get_id() at the moment, but it may come later
 148                         hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 149                         if (hash == GNUTLS_DIG_UNKNOWN)
 150                                 throw Exception("Unknown hash type " + hashname);
 151
 152                         // Check if the user is giving us something that is a valid MAC but not digest
 153                         gnutls_hash_hd_t is_digest;
 154                         if (gnutls_hash_init(&is_digest, hash) < 0)
 155                                 throw Exception("Unknown hash type " + hashname);
 156                         gnutls_hash_deinit(is_digest, NULL);
 157 #else
 158                         if (hashname == "md5")
 159                                 hash = GNUTLS_DIG_MD5;
 160                         else if (hashname == "sha1")
 161                                 hash = GNUTLS_DIG_SHA1;
 162 #ifdef INSPIRCD_GNUTLS_ENABLE_SHA256_FINGERPRINT
 163                         else if (hashname == "sha256")
 164                                 hash = GNUTLS_DIG_SHA256;
 165 #endif
 166                         else
 167                                 throw Exception("Unknown hash type " + hashname);
 168 #endif
 169                 }
 170
 171                 gnutls_digest_algorithm_t get() const { return hash; }
 172         };
 173
 174         class DHParams
 175         {
 176                 gnutls_dh_params_t dh_params;
 177
 178                 DHParams()
 179                 {
 180                         ThrowOnError(gnutls_dh_params_init(&dh_params), "gnutls_dh_params_init() failed");
 181                 }
 182
 183          public:
 184                 /** Import */
 185                 static std::auto_ptr<DHParams> Import(const std::string& dhstr)
 186                 {
 187                         std::auto_ptr<DHParams> dh(new DHParams);
 188                         int ret = gnutls_dh_params_import_pkcs3(dh->dh_params, Datum(dhstr).get(), GNUTLS_X509_FMT_PEM);
 189                         ThrowOnError(ret, "Unable to import DH params");
 190                         return dh;
 191                 }
 192
 193                 /** Generate */
 194                 static std::auto_ptr<DHParams> Generate(unsigned int bits)
 195                 {
 196                         std::auto_ptr<DHParams> dh(new DHParams);
 197                         ThrowOnError(gnutls_dh_params_generate2(dh->dh_params, bits), "Unable to generate DH params");
 198                         return dh;
 199                 }
 200
 201                 ~DHParams()
 202                 {
 203                         gnutls_dh_params_deinit(dh_params);
 204                 }
 205
 206                 const gnutls_dh_params_t& get() const { return dh_params; }
 207         };
 208
 209         class X509Key
 210         {
 211                 /** Ensure that the key is deinited in case the constructor of X509Key throws
 212                  */
 213                 class RAIIKey
 214                 {
 215                  public:
 216                         gnutls_x509_privkey_t key;
 217
 218                         RAIIKey()
 219                         {
 220                                 ThrowOnError(gnutls_x509_privkey_init(&key), "gnutls_x509_privkey_init() failed");
 221                         }
 222
 223                         ~RAIIKey()
 224                         {
 225                                 gnutls_x509_privkey_deinit(key);
 226                         }
 227                 } key;
 228
 229          public:
 230                 /** Import */
 231                 X509Key(const std::string& keystr)
 232                 {
 233                         int ret = gnutls_x509_privkey_import(key.key, Datum(keystr).get(), GNUTLS_X509_FMT_PEM);
 234                         ThrowOnError(ret, "Unable to import private key");
 235                 }
 236
 237                 gnutls_x509_privkey_t& get() { return key.key; }
 238         };
 239
 240         class X509CertList
 241         {
 242                 std::vector<gnutls_x509_crt_t> certs;
 243
 244          public:
 245                 /** Import */
 246                 X509CertList(const std::string& certstr)
 247                 {
 248                         unsigned int certcount = 3;
 249                         certs.resize(certcount);
 250                         Datum datum(certstr);
 251
 252                         int ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 253                         if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 254                         {
 255                                 // the buffer wasn't big enough to hold all certs but gnutls changed certcount to the number of available certs,
 256                                 // try again with a bigger buffer
 257                                 certs.resize(certcount);
 258                                 ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 259                         }
 260
 261                         ThrowOnError(ret, "Unable to load certificates");
 262
 263                         // Resize the vector to the actual number of certs because we rely on its size being correct
 264                         // when deallocating the certs
 265                         certs.resize(certcount);
 266                 }
 267
 268                 ~X509CertList()
 269                 {
 270                         for (std::vector<gnutls_x509_crt_t>::iterator i = certs.begin(); i != certs.end(); ++i)
 271                                 gnutls_x509_crt_deinit(*i);
 272                 }
 273
 274                 gnutls_x509_crt_t* raw() { return &certs[0]; }
 275                 unsigned int size() const { return certs.size(); }
 276         };
 277
 278         class X509CRL : public refcountbase
 279         {
 280                 class RAIICRL
 281                 {
 282                  public:
 283                         gnutls_x509_crl_t crl;
 284
 285                         RAIICRL()
 286                         {
 287                                 ThrowOnError(gnutls_x509_crl_init(&crl), "gnutls_x509_crl_init() failed");
 288                         }
 289
 290                         ~RAIICRL()
 291                         {
 292                                 gnutls_x509_crl_deinit(crl);
 293                         }
 294                 } crl;
 295
 296          public:
 297                 /** Import */
 298                 X509CRL(const std::string& crlstr)
 299                 {
 300                         int ret = gnutls_x509_crl_import(get(), Datum(crlstr).get(), GNUTLS_X509_FMT_PEM);
 301                         ThrowOnError(ret, "Unable to load certificate revocation list");
 302                 }
 303
 304                 gnutls_x509_crl_t& get() { return crl.crl; }
 305         };
 306
 307 #ifdef GNUTLS_NEW_PRIO_API
 308         class Priority
 309         {
 310                 gnutls_priority_t priority;
 311
 312          public:
 313                 Priority(const std::string& priorities)
 314                 {
 315                         // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 316                         // If the user did not supply anything then the string is already set to "NORMAL"
 317                         const char* priocstr = priorities.c_str();
 318                         const char* prioerror;
 319
 320                         int ret = gnutls_priority_init(&priority, priocstr, &prioerror);
 321                         if (ret < 0)
 322                         {
 323                                 // gnutls did not understand the user supplied string
 324                                 throw Exception("Unable to initialize priorities to \"" + priorities + "\": " + gnutls_strerror(ret) + " Syntax error at position " + ConvToStr((unsigned int) (prioerror - priocstr)));
 325                         }
 326                 }
 327
 328                 ~Priority()
 329                 {
 330                         gnutls_priority_deinit(priority);
 331                 }
 332
 333                 void SetupSession(gnutls_session_t sess)
 334                 {
 335                         gnutls_priority_set(sess, priority);
 336                 }
 337         };
 338 #else
 339         /** Dummy class, used when gnutls_priority_set() is not available
 340          */
 341         class Priority
 342         {
 343          public:
 344                 Priority(const std::string& priorities)
 345                 {
 346                         if (priorities != "NORMAL")
 347                                 throw Exception("You've set a non-default priority string, but GnuTLS lacks support for it");
 348                 }
 349
 350                 static void SetupSession(gnutls_session_t sess)
 351                 {
 352                         // Always set the default priorities
 353                         gnutls_set_default_priority(sess);
 354                 }
 355         };
 356 #endif
 357
 358         class CertCredentials
 359         {
 360                 /** DH parameters associated with these credentials
 361                  */
 362                 std::auto_ptr<DHParams> dh;
 363
 364          protected:
 365                 gnutls_certificate_credentials_t cred;
 366
 367          public:
 368                 CertCredentials()
 369                 {
 370                         ThrowOnError(gnutls_certificate_allocate_credentials(&cred), "Cannot allocate certificate credentials");
 371                 }
 372
 373                 ~CertCredentials()
 374                 {
 375                         gnutls_certificate_free_credentials(cred);
 376                 }
 377
 378                 /** Associates these credentials with the session
 379                  */
 380                 void SetupSession(gnutls_session_t sess)
 381                 {
 382                         gnutls_credentials_set(sess, GNUTLS_CRD_CERTIFICATE, cred);
 383                 }
 384
 385                 /** Set the given DH parameters to be used with these credentials
 386                  */
 387                 void SetDH(std::auto_ptr<DHParams>& DH)
 388                 {
 389                         dh = DH;
 390                         gnutls_certificate_set_dh_params(cred, dh->get());
 391                 }
 392         };
 393
 394         class X509Credentials : public CertCredentials
 395         {
 396                 /** Private key
 397                  */
 398                 X509Key key;
 399
 400                 /** Certificate list, presented to the peer
 401                  */
 402                 X509CertList certs;
 403
 404                 /** Trusted CA, may be NULL
 405                  */
 406                 std::auto_ptr<X509CertList> trustedca;
 407
 408                 /** Certificate revocation list, may be NULL
 409                  */
 410                 std::auto_ptr<X509CRL> crl;
 411
 412                 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);
 413
 414          public:
 415                 X509Credentials(const std::string& certstr, const std::string& keystr)
 416                         : key(keystr)
 417                         , certs(certstr)
 418                 {
 419                         // Throwing is ok here, the destructor of Credentials is called in that case
 420                         int ret = gnutls_certificate_set_x509_key(cred, certs.raw(), certs.size(), key.get());
 421                         ThrowOnError(ret, "Unable to set cert/key pair");
 422
 423 #ifdef GNUTLS_NEW_CERT_CALLBACK_API
 424                         gnutls_certificate_set_retrieve_function(cred, cert_callback);
 425 #else
 426                         gnutls_certificate_client_set_retrieve_function(cred, cert_callback);
 427 #endif
 428                 }
 429
 430                 /** Sets the trusted CA and the certificate revocation list
 431                  * to use when verifying certificates
 432                  */
 433                 void SetCA(std::auto_ptr<X509CertList>& certlist, std::auto_ptr<X509CRL>& CRL)
 434                 {
 435                         // Do nothing if certlist is NULL
 436                         if (certlist.get())
 437                         {
 438                                 int ret = gnutls_certificate_set_x509_trust(cred, certlist->raw(), certlist->size());
 439                                 ThrowOnError(ret, "gnutls_certificate_set_x509_trust() failed");
 440
 441                                 if (CRL.get())
 442                                 {
 443                                         ret = gnutls_certificate_set_x509_crl(cred, &CRL->get(), 1);
 444                                         ThrowOnError(ret, "gnutls_certificate_set_x509_crl() failed");
 445                                 }
 446
 447                                 trustedca = certlist;
 448                                 crl = CRL;
 449                         }
 450                 }
 451         };
 452
 453         class Profile : public refcountbase
 454         {
 455                 /** Name of this profile
 456                  */
 457                 const std::string name;
 458
 459                 /** X509 certificate(s) and key
 460                  */
 461                 X509Credentials x509cred;
 462
 463                 /** The minimum length in bits for the DH prime to be accepted as a client
 464                  */
 465                 unsigned int min_dh_bits;
 466
 467                 /** Hashing algorithm to use when generating certificate fingerprints
 468                  */
 469                 Hash hash;
 470
 471                 /** Priorities for ciphers, compression methods, etc.
 472                  */
 473                 Priority priority;
 474
 475                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 476                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 477                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL)
 478                         : name(profilename)
 479                         , x509cred(certstr, keystr)
 480                         , min_dh_bits(mindh)
 481                         , hash(hashstr)
 482                         , priority(priostr)
 483                 {
 484                         x509cred.SetDH(DH);
 485                         x509cred.SetCA(CA, CRL);
 486                 }
 487
 488                 static std::string ReadFile(const std::string& filename)
 489                 {
 490                         FileReader reader(filename);
 491                         std::string ret = reader.GetString();
 492                         if (ret.empty())
 493                                 throw Exception("Cannot read file " + filename);
 494                         return ret;
 495                 }
 496
 497          public:
 498                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 499                 {
 500                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 501                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 502
 503                         std::auto_ptr<DHParams> dh;
 504                         int gendh = tag->getInt("gendh");
 505                         if (gendh)
 506                         {
 507                                 gendh = (gendh < 1024 ? 1024 : gendh);
 508                                 dh = DHParams::Generate(gendh);
 509                         }
 510                         else
 511                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 512
 513                         // Use default priority string if this tag does not specify one
 514                         std::string priostr = tag->getString("priority", "NORMAL");
 515                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 516                         std::string hashstr = tag->getString("hash", "md5");
 517
 518                         // Load trusted CA and revocation list, if set
 519                         std::auto_ptr<X509CertList> ca;
 520                         std::auto_ptr<X509CRL> crl;
 521                         std::string filename = tag->getString("cafile");
 522                         if (!filename.empty())
 523                         {
 524                                 ca.reset(new X509CertList(ReadFile(filename)));
 525
 526                                 filename = tag->getString("crlfile");
 527                                 if (!filename.empty())
 528                                         crl.reset(new X509CRL(ReadFile(filename)));
 529                         }
 530
 531                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl);
 532                 }
 533
 534                 /** Set up the given session with the settings in this profile
 535                  */
 536                 void SetupSession(gnutls_session_t sess)
 537                 {
 538                         priority.SetupSession(sess);
 539                         x509cred.SetupSession(sess);
 540                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 541                 }
 542
 543                 const std::string& GetName() const { return name; }
 544                 X509Credentials& GetX509Credentials() { return x509cred; }
 545                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 546         };
 547 }
 548
 549 class GnuTLSIOHook : public SSLIOHook
 550 {
 551  private:
 552         gnutls_session_t sess;
 553         issl_status status;
 554         reference<GnuTLS::Profile> profile;
 555
 556         void InitSession(StreamSocket* user, bool me_server)
 557         {
 558                 gnutls_init(&sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 559
 560                 profile->SetupSession(sess);
 561                 gnutls_transport_set_ptr(sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 562                 gnutls_transport_set_push_function(sess, gnutls_push_wrapper);
 563                 gnutls_transport_set_pull_function(sess, gnutls_pull_wrapper);
 564
 565                 if (me_server)
 566                         gnutls_certificate_server_set_request(sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 567         }
 568
 569         void CloseSession()
 570         {
 571                 if (this->sess)
 572                 {
 573                         gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 574                         gnutls_deinit(this->sess);
 575                 }
 576                 sess = NULL;
 577                 certificate = NULL;
 578                 status = ISSL_NONE;
 579         }
 580
 581         bool Handshake(StreamSocket* user)
 582         {
 583                 int ret = gnutls_handshake(this->sess);
 584
 585                 if (ret < 0)
 586                 {
 587                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 588                         {
 589                                 // Handshake needs resuming later, read() or write() would have blocked.
 590
 591                                 if (gnutls_record_get_direction(this->sess) == 0)
 592                                 {
 593                                         // gnutls_handshake() wants to read() again.
 594                                         this->status = ISSL_HANDSHAKING_READ;
 595                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 596                                 }
 597                                 else
 598                                 {
 599                                         // gnutls_handshake() wants to write() again.
 600                                         this->status = ISSL_HANDSHAKING_WRITE;
 601                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 602                                 }
 603                         }
 604                         else
 605                         {
 606                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 607                                 CloseSession();
 608                                 this->status = ISSL_CLOSING;
 609                         }
 610
 611                         return false;
 612                 }
 613                 else
 614                 {
 615                         // Change the seesion state
 616                         this->status = ISSL_HANDSHAKEN;
 617
 618                         VerifyCertificate();
 619
 620                         // Finish writing, if any left
 621                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 622
 623                         return true;
 624                 }
 625         }
 626
 627         void VerifyCertificate()
 628         {
 629                 unsigned int certstatus;
 630                 const gnutls_datum_t* cert_list;
 631                 int ret;
 632                 unsigned int cert_list_size;
 633                 gnutls_x509_crt_t cert;
 634                 char str[512];
 635                 unsigned char digest[512];
 636                 size_t digest_size = sizeof(digest);
 637                 size_t name_size = sizeof(str);
 638                 ssl_cert* certinfo = new ssl_cert;
 639                 this->certificate = certinfo;
 640
 641                 /* This verification function uses the trusted CAs in the credentials
 642                  * structure. So you must have installed one or more CA certificates.
 643                  */
 644                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 645
 646                 if (ret < 0)
 647                 {
 648                         certinfo->error = std::string(gnutls_strerror(ret));
 649                         return;
 650                 }
 651
 652                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 653                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 654                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 655                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 656
 657                 /* Up to here the process is the same for X.509 certificates and
 658                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 659                  * be easily extended to work with openpgp keys as well.
 660                  */
 661                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 662                 {
 663                         certinfo->error = "No X509 keys sent";
 664                         return;
 665                 }
 666
 667                 ret = gnutls_x509_crt_init(&cert);
 668                 if (ret < 0)
 669                 {
 670                         certinfo->error = gnutls_strerror(ret);
 671                         return;
 672                 }
 673
 674                 cert_list_size = 0;
 675                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 676                 if (cert_list == NULL)
 677                 {
 678                         certinfo->error = "No certificate was found";
 679                         goto info_done_dealloc;
 680                 }
 681
 682                 /* This is not a real world example, since we only check the first
 683                  * certificate in the given chain.
 684                  */
 685
 686                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 687                 if (ret < 0)
 688                 {
 689                         certinfo->error = gnutls_strerror(ret);
 690                         goto info_done_dealloc;
 691                 }
 692
 693                 if (gnutls_x509_crt_get_dn(cert, str, &name_size) == 0)
 694                 {
 695                         std::string& dn = certinfo->dn;
 696                         dn = str;
 697                         // Make sure there are no chars in the string that we consider invalid
 698                         if (dn.find_first_of("\r\n") != std::string::npos)
 699                                 dn.clear();
 700                 }
 701
 702                 name_size = sizeof(str);
 703                 if (gnutls_x509_crt_get_issuer_dn(cert, str, &name_size) == 0)
 704                 {
 705                         std::string& issuer = certinfo->issuer;
 706                         issuer = str;
 707                         if (issuer.find_first_of("\r\n") != std::string::npos)
 708                                 issuer.clear();
 709                 }
 710
 711                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 712                 {
 713                         certinfo->error = gnutls_strerror(ret);
 714                 }
 715                 else
 716                 {
 717                         certinfo->fingerprint = BinToHex(digest, digest_size);
 718                 }
 719
 720                 /* Beware here we do not check for errors.
 721                  */
 722                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 723                 {
 724                         certinfo->error = "Not activated, or expired certificate";
 725                 }
 726
 727 info_done_dealloc:
 728                 gnutls_x509_crt_deinit(cert);
 729         }
 730
 731         static const char* UnknownIfNULL(const char* str)
 732         {
 733                 return str ? str : "UNKNOWN";
 734         }
 735
 736         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 737         {
 738                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 739 #ifdef _WIN32
 740                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 741 #endif
 742
 743                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 744                 {
 745 #ifdef _WIN32
 746                         gnutls_transport_set_errno(session->sess, EAGAIN);
 747 #else
 748                         errno = EAGAIN;
 749 #endif
 750                         return -1;
 751                 }
 752
 753                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 754
 755 #ifdef _WIN32
 756                 if (rv < 0)
 757                 {
 758                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 759                          * and then set errno appropriately.
 760                          * The gnutls library may also have a different errno variable than us, see
 761                          * gnutls_transport_set_errno(3).
 762                          */
 763                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 764                 }
 765 #endif
 766
 767                 if (rv < (int)size)
 768                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 769                 return rv;
 770         }
 771
 772         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 773         {
 774                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 775 #ifdef _WIN32
 776                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 777 #endif
 778
 779                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 780                 {
 781 #ifdef _WIN32
 782                         gnutls_transport_set_errno(session->sess, EAGAIN);
 783 #else
 784                         errno = EAGAIN;
 785 #endif
 786                         return -1;
 787                 }
 788
 789                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 790
 791 #ifdef _WIN32
 792                 if (rv < 0)
 793                 {
 794                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 795                          * and then set errno appropriately.
 796                          * The gnutls library may also have a different errno variable than us, see
 797                          * gnutls_transport_set_errno(3).
 798                          */
 799                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 800                 }
 801 #endif
 802
 803                 if (rv < (int)size)
 804                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 805                 return rv;
 806         }
 807
 808  public:
 809         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool outbound, const reference<GnuTLS::Profile>& sslprofile)
 810                 : SSLIOHook(hookprov)
 811                 , sess(NULL)
 812                 , status(ISSL_NONE)
 813                 , profile(sslprofile)
 814         {
 815                 InitSession(sock, outbound);
 816                 sock->AddIOHook(this);
 817                 Handshake(sock);
 818         }
 819
 820         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 821         {
 822                 CloseSession();
 823         }
 824
 825         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 826         {
 827                 if (!this->sess)
 828                 {
 829                         CloseSession();
 830                         user->SetError("No SSL session");
 831                         return -1;
 832                 }
 833
 834                 if (this->status == ISSL_HANDSHAKING_READ || this->status == ISSL_HANDSHAKING_WRITE)
 835                 {
 836                         // The handshake isn't finished, try to finish it.
 837
 838                         if (!Handshake(user))
 839                         {
 840                                 if (this->status != ISSL_CLOSING)
 841                                         return 0;
 842                                 return -1;
 843                         }
 844                 }
 845
 846                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 847
 848                 if (this->status == ISSL_HANDSHAKEN)
 849                 {
 850                         char* buffer = ServerInstance->GetReadBuffer();
 851                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 852                         int ret = gnutls_record_recv(this->sess, buffer, bufsiz);
 853                         if (ret > 0)
 854                         {
 855                                 recvq.append(buffer, ret);
 856                                 return 1;
 857                         }
 858                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 859                         {
 860                                 return 0;
 861                         }
 862                         else if (ret == 0)
 863                         {
 864                                 user->SetError("Connection closed");
 865                                 CloseSession();
 866                                 return -1;
 867                         }
 868                         else
 869                         {
 870                                 user->SetError(gnutls_strerror(ret));
 871                                 CloseSession();
 872                                 return -1;
 873                         }
 874                 }
 875                 else if (this->status == ISSL_CLOSING)
 876                         return -1;
 877
 878                 return 0;
 879         }
 880
 881         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 882         {
 883                 if (!this->sess)
 884                 {
 885                         CloseSession();
 886                         user->SetError("No SSL session");
 887                         return -1;
 888                 }
 889
 890                 if (this->status == ISSL_HANDSHAKING_WRITE || this->status == ISSL_HANDSHAKING_READ)
 891                 {
 892                         // The handshake isn't finished, try to finish it.
 893                         Handshake(user);
 894                         if (this->status != ISSL_CLOSING)
 895                                 return 0;
 896                         return -1;
 897                 }
 898
 899                 int ret = 0;
 900
 901                 if (this->status == ISSL_HANDSHAKEN)
 902                 {
 903                         ret = gnutls_record_send(this->sess, sendq.data(), sendq.length());
 904
 905                         if (ret == (int)sendq.length())
 906                         {
 907                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 908                                 return 1;
 909                         }
 910                         else if (ret > 0)
 911                         {
 912                                 sendq = sendq.substr(ret);
 913                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 914                                 return 0;
 915                         }
 916                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 917                         {
 918                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 919                                 return 0;
 920                         }
 921                         else // (ret < 0)
 922                         {
 923                                 user->SetError(gnutls_strerror(ret));
 924                                 CloseSession();
 925                                 return -1;
 926                         }
 927                 }
 928
 929                 return 0;
 930         }
 931
 932         void TellCiphersAndFingerprint(LocalUser* user)
 933         {
 934                 if (sess)
 935                 {
 936                         std::string text = "*** You are connected using SSL cipher '";
 937
 938                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 939                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 940                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 941
 942                         if (!certificate->fingerprint.empty())
 943                                 text += " and your SSL certificate fingerprint is " + certificate->fingerprint;
 944
 945                         user->WriteNotice(text);
 946                 }
 947         }
 948
 949         GnuTLS::Profile* GetProfile() { return profile; }
 950 };
 951
 952 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)
 953 {
 954 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
 955         st->type = GNUTLS_CRT_X509;
 956 #else
 957         st->cert_type = GNUTLS_CRT_X509;
 958         st->key_type = GNUTLS_PRIVKEY_X509;
 959 #endif
 960         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
 961         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
 962
 963         st->ncerts = cred.certs.size();
 964         st->cert.x509 = cred.certs.raw();
 965         st->key.x509 = cred.key.get();
 966         st->deinit_all = 0;
 967
 968         return 0;
 969 }
 970
 971 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
 972 {
 973         reference<GnuTLS::Profile> profile;
 974
 975  public:
 976         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
 977                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
 978                 , profile(prof)
 979         {
 980                 ServerInstance->Modules->AddService(*this);
 981         }
 982
 983         ~GnuTLSIOHookProvider()
 984         {
 985                 ServerInstance->Modules->DelService(*this);
 986         }
 987
 988         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 989         {
 990                 new GnuTLSIOHook(this, sock, true, profile);
 991         }
 992
 993         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
 994         {
 995                 new GnuTLSIOHook(this, sock, false, profile);
 996         }
 997 };
 998
 999 class ModuleSSLGnuTLS : public Module
1000 {
1001         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
1002
1003         // First member of the class, gets constructed first and destructed last
1004         GnuTLS::Init libinit;
1005         RandGen randhandler;
1006         ProfileList profiles;
1007
1008         void ReadProfiles()
1009         {
1010                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1011                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1012                 // avoiding unpleasant situations where no new SSL connections are possible.
1013                 ProfileList newprofiles;
1014
1015                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1016                 if (tags.first == tags.second)
1017                 {
1018                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1019                         const std::string defname = "gnutls";
1020                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1021                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1022
1023                         try
1024                         {
1025                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1026                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1027                         }
1028                         catch (CoreException& ex)
1029                         {
1030                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1031                         }
1032                 }
1033
1034                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1035                 {
1036                         ConfigTag* tag = i->second;
1037                         if (tag->getString("provider") != "gnutls")
1038                                 continue;
1039
1040                         std::string name = tag->getString("name");
1041                         if (name.empty())
1042                         {
1043                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1044                                 continue;
1045                         }
1046
1047                         reference<GnuTLS::Profile> profile;
1048                         try
1049                         {
1050                                 profile = GnuTLS::Profile::Create(name, tag);
1051                         }
1052                         catch (CoreException& ex)
1053                         {
1054                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1055                         }
1056
1057                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1058                 }
1059
1060                 // New profiles are ok, begin using them
1061                 // Old profiles are deleted when their refcount drops to zero
1062                 profiles.swap(newprofiles);
1063         }
1064
1065  public:
1066         ModuleSSLGnuTLS()
1067         {
1068 #ifndef GNUTLS_HAS_RND
1069                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1070 #endif
1071         }
1072
1073         void init() CXX11_OVERRIDE
1074         {
1075                 ReadProfiles();
1076                 ServerInstance->GenRandom = &randhandler;
1077         }
1078
1079         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1080         {
1081                 if(param != "ssl")
1082                         return;
1083
1084                 try
1085                 {
1086                         ReadProfiles();
1087                 }
1088                 catch (ModuleException& ex)
1089                 {
1090                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1091                 }
1092         }
1093
1094         ~ModuleSSLGnuTLS()
1095         {
1096                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1097         }
1098
1099         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1100         {
1101                 if(target_type == TYPE_USER)
1102                 {
1103                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1104
1105                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1106                         {
1107                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1108                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1109                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1110                         }
1111                 }
1112         }
1113
1114         Version GetVersion() CXX11_OVERRIDE
1115         {
1116                 return Version("Provides SSL support for clients", VF_VENDOR);
1117         }
1118
1119         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1120         {
1121                 IOHook* hook = user->eh.GetIOHook();
1122                 if (hook && hook->prov->creator == this)
1123                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1124         }
1125 };
1126
1127 MODULE_INIT(ModuleSSLGnuTLS)