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.lib")
  51 # pragma comment(lib, "libgcrypt.lib")
  52 # pragma comment(lib, "libgpg-error.lib")
  53 # pragma comment(lib, "user32.lib")
  54 # pragma comment(lib, "advapi32.lib")
  55 # pragma comment(lib, "libgcc.lib")
  56 # pragma comment(lib, "libmingwex.lib")
  57 # pragma comment(lib, "gdi32.lib")
  58 #endif
  59
  60 /* $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'") */
  61 /* $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'") */
  62
  63 #ifndef GNUTLS_VERSION_MAJOR
  64 #define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
  65 #define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
  66 #define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
  67 #endif
  68
  69 // These don't exist in older GnuTLS versions
  70 #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))
  71 #define GNUTLS_NEW_PRIO_API
  72 #endif
  73
  74 #if(GNUTLS_VERSION_MAJOR < 2)
  75 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  76 typedef gnutls_dh_params_t gnutls_dh_params;
  77 #endif
  78
  79 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  80
  81 #if (GNUTLS_VERSION_MAJOR > 2 || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR >= 12))
  82 #define GNUTLS_NEW_CERT_CALLBACK_API
  83 typedef gnutls_retr2_st cert_cb_last_param_type;
  84 #else
  85 typedef gnutls_retr_st cert_cb_last_param_type;
  86 #endif
  87
  88 class RandGen : public HandlerBase2<void, char*, size_t>
  89 {
  90  public:
  91         void Call(char* buffer, size_t len)
  92         {
  93 #ifdef GNUTLS_HAS_RND
  94                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
  95 #else
  96                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  97 #endif
  98         }
  99 };
 100
 101 namespace GnuTLS
 102 {
 103         class Init
 104         {
 105          public:
 106                 Init() { gnutls_global_init(); }
 107                 ~Init() { gnutls_global_deinit(); }
 108         };
 109
 110         class Exception : public ModuleException
 111         {
 112          public:
 113                 Exception(const std::string& reason)
 114                         : ModuleException(reason) { }
 115         };
 116
 117         void ThrowOnError(int errcode, const char* msg)
 118         {
 119                 if (errcode < 0)
 120                 {
 121                         std::string reason = msg;
 122                         reason.append(" :").append(gnutls_strerror(errcode));
 123                         throw Exception(reason);
 124                 }
 125         }
 126
 127         /** Used to create a gnutls_datum_t* from a std::string
 128          */
 129         class Datum
 130         {
 131                 gnutls_datum_t datum;
 132
 133          public:
 134                 Datum(const std::string& dat)
 135                 {
 136                         datum.data = (unsigned char*)dat.data();
 137                         datum.size = static_cast<unsigned int>(dat.length());
 138                 }
 139
 140                 const gnutls_datum_t* get() const { return &datum; }
 141         };
 142
 143         class Hash
 144         {
 145                 gnutls_digest_algorithm_t hash;
 146
 147          public:
 148                 // Nothing to deallocate, constructor may throw freely
 149                 Hash(const std::string& hashname)
 150                 {
 151                         // As older versions of gnutls can't do this, let's disable it where needed.
 152 #ifdef GNUTLS_HAS_MAC_GET_ID
 153                         // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 154                         // There is no gnutls_dig_get_id() at the moment, but it may come later
 155                         hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 156                         if (hash == GNUTLS_DIG_UNKNOWN)
 157                                 throw Exception("Unknown hash type " + hashname);
 158
 159                         // Check if the user is giving us something that is a valid MAC but not digest
 160                         gnutls_hash_hd_t is_digest;
 161                         if (gnutls_hash_init(&is_digest, hash) < 0)
 162                                 throw Exception("Unknown hash type " + hashname);
 163                         gnutls_hash_deinit(is_digest, NULL);
 164 #else
 165                         if (hashname == "md5")
 166                                 hash = GNUTLS_DIG_MD5;
 167                         else if (hashname == "sha1")
 168                                 hash = GNUTLS_DIG_SHA1;
 169                         else
 170                                 throw Exception("Unknown hash type " + hashname);
 171 #endif
 172                 }
 173
 174                 gnutls_digest_algorithm_t get() const { return hash; }
 175         };
 176
 177         class DHParams
 178         {
 179                 gnutls_dh_params_t dh_params;
 180
 181                 DHParams()
 182                 {
 183                         ThrowOnError(gnutls_dh_params_init(&dh_params), "gnutls_dh_params_init() failed");
 184                 }
 185
 186          public:
 187                 /** Import */
 188                 static std::auto_ptr<DHParams> Import(const std::string& dhstr)
 189                 {
 190                         std::auto_ptr<DHParams> dh(new DHParams);
 191                         int ret = gnutls_dh_params_import_pkcs3(dh->dh_params, Datum(dhstr).get(), GNUTLS_X509_FMT_PEM);
 192                         ThrowOnError(ret, "Unable to import DH params");
 193                         return dh;
 194                 }
 195
 196                 /** Generate */
 197                 static std::auto_ptr<DHParams> Generate(unsigned int bits)
 198                 {
 199                         std::auto_ptr<DHParams> dh(new DHParams);
 200                         ThrowOnError(gnutls_dh_params_generate2(dh->dh_params, bits), "Unable to generate DH params");
 201                         return dh;
 202                 }
 203
 204                 ~DHParams()
 205                 {
 206                         gnutls_dh_params_deinit(dh_params);
 207                 }
 208
 209                 const gnutls_dh_params_t& get() const { return dh_params; }
 210         };
 211
 212         class X509Key
 213         {
 214                 /** Ensure that the key is deinited in case the constructor of X509Key throws
 215                  */
 216                 class RAIIKey
 217                 {
 218                  public:
 219                         gnutls_x509_privkey_t key;
 220
 221                         RAIIKey()
 222                         {
 223                                 ThrowOnError(gnutls_x509_privkey_init(&key), "gnutls_x509_privkey_init() failed");
 224                         }
 225
 226                         ~RAIIKey()
 227                         {
 228                                 gnutls_x509_privkey_deinit(key);
 229                         }
 230                 } key;
 231
 232          public:
 233                 /** Import */
 234                 X509Key(const std::string& keystr)
 235                 {
 236                         int ret = gnutls_x509_privkey_import(key.key, Datum(keystr).get(), GNUTLS_X509_FMT_PEM);
 237                         ThrowOnError(ret, "Unable to import private key");
 238                 }
 239
 240                 gnutls_x509_privkey_t& get() { return key.key; }
 241         };
 242
 243         class X509CertList
 244         {
 245                 std::vector<gnutls_x509_crt_t> certs;
 246
 247          public:
 248                 /** Import */
 249                 X509CertList(const std::string& certstr)
 250                 {
 251                         unsigned int certcount = 3;
 252                         certs.resize(certcount);
 253                         Datum datum(certstr);
 254
 255                         int ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 256                         if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 257                         {
 258                                 // the buffer wasn't big enough to hold all certs but gnutls changed certcount to the number of available certs,
 259                                 // try again with a bigger buffer
 260                                 certs.resize(certcount);
 261                                 ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 262                         }
 263
 264                         ThrowOnError(ret, "Unable to load certificates");
 265
 266                         // Resize the vector to the actual number of certs because we rely on its size being correct
 267                         // when deallocating the certs
 268                         certs.resize(certcount);
 269                 }
 270
 271                 ~X509CertList()
 272                 {
 273                         for (std::vector<gnutls_x509_crt_t>::iterator i = certs.begin(); i != certs.end(); ++i)
 274                                 gnutls_x509_crt_deinit(*i);
 275                 }
 276
 277                 gnutls_x509_crt_t* raw() { return &certs[0]; }
 278                 unsigned int size() const { return certs.size(); }
 279         };
 280
 281         class X509CRL : public refcountbase
 282         {
 283                 class RAIICRL
 284                 {
 285                  public:
 286                         gnutls_x509_crl_t crl;
 287
 288                         RAIICRL()
 289                         {
 290                                 ThrowOnError(gnutls_x509_crl_init(&crl), "gnutls_x509_crl_init() failed");
 291                         }
 292
 293                         ~RAIICRL()
 294                         {
 295                                 gnutls_x509_crl_deinit(crl);
 296                         }
 297                 } crl;
 298
 299          public:
 300                 /** Import */
 301                 X509CRL(const std::string& crlstr)
 302                 {
 303                         int ret = gnutls_x509_crl_import(get(), Datum(crlstr).get(), GNUTLS_X509_FMT_PEM);
 304                         ThrowOnError(ret, "Unable to load certificate revocation list");
 305                 }
 306
 307                 gnutls_x509_crl_t& get() { return crl.crl; }
 308         };
 309
 310 #ifdef GNUTLS_NEW_PRIO_API
 311         class Priority
 312         {
 313                 gnutls_priority_t priority;
 314
 315          public:
 316                 Priority(const std::string& priorities)
 317                 {
 318                         // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 319                         // If the user did not supply anything then the string is already set to "NORMAL"
 320                         const char* priocstr = priorities.c_str();
 321                         const char* prioerror;
 322
 323                         int ret = gnutls_priority_init(&priority, priocstr, &prioerror);
 324                         if (ret < 0)
 325                         {
 326                                 // gnutls did not understand the user supplied string
 327                                 throw Exception("Unable to initialize priorities to \"" + priorities + "\": " + gnutls_strerror(ret) + " Syntax error at position " + ConvToStr((unsigned int) (prioerror - priocstr)));
 328                         }
 329                 }
 330
 331                 ~Priority()
 332                 {
 333                         gnutls_priority_deinit(priority);
 334                 }
 335
 336                 void SetupSession(gnutls_session_t sess)
 337                 {
 338                         gnutls_priority_set(sess, priority);
 339                 }
 340         };
 341 #else
 342         /** Dummy class, used when gnutls_priority_set() is not available
 343          */
 344         class Priority
 345         {
 346          public:
 347                 Priority(const std::string& priorities)
 348                 {
 349                         if (priorities != "NORMAL")
 350                                 throw Exception("You've set a non-default priority string, but GnuTLS lacks support for it");
 351                 }
 352
 353                 static void SetupSession(gnutls_session_t sess)
 354                 {
 355                         // Always set the default priorities
 356                         gnutls_set_default_priority(sess);
 357                 }
 358         };
 359 #endif
 360
 361         class CertCredentials
 362         {
 363                 /** DH parameters associated with these credentials
 364                  */
 365                 std::auto_ptr<DHParams> dh;
 366
 367          protected:
 368                 gnutls_certificate_credentials_t cred;
 369
 370          public:
 371                 CertCredentials()
 372                 {
 373                         ThrowOnError(gnutls_certificate_allocate_credentials(&cred), "Cannot allocate certificate credentials");
 374                 }
 375
 376                 ~CertCredentials()
 377                 {
 378                         gnutls_certificate_free_credentials(cred);
 379                 }
 380
 381                 /** Associates these credentials with the session
 382                  */
 383                 void SetupSession(gnutls_session_t sess)
 384                 {
 385                         gnutls_credentials_set(sess, GNUTLS_CRD_CERTIFICATE, cred);
 386                 }
 387
 388                 /** Set the given DH parameters to be used with these credentials
 389                  */
 390                 void SetDH(std::auto_ptr<DHParams>& DH)
 391                 {
 392                         dh = DH;
 393                         gnutls_certificate_set_dh_params(cred, dh->get());
 394                 }
 395         };
 396
 397         class X509Credentials : public CertCredentials
 398         {
 399                 /** Private key
 400                  */
 401                 X509Key key;
 402
 403                 /** Certificate list, presented to the peer
 404                  */
 405                 X509CertList certs;
 406
 407                 /** Trusted CA, may be NULL
 408                  */
 409                 std::auto_ptr<X509CertList> trustedca;
 410
 411                 /** Certificate revocation list, may be NULL
 412                  */
 413                 std::auto_ptr<X509CRL> crl;
 414
 415                 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);
 416
 417          public:
 418                 X509Credentials(const std::string& certstr, const std::string& keystr)
 419                         : key(keystr)
 420                         , certs(certstr)
 421                 {
 422                         // Throwing is ok here, the destructor of Credentials is called in that case
 423                         int ret = gnutls_certificate_set_x509_key(cred, certs.raw(), certs.size(), key.get());
 424                         ThrowOnError(ret, "Unable to set cert/key pair");
 425
 426 #ifdef GNUTLS_NEW_CERT_CALLBACK_API
 427                         gnutls_certificate_set_retrieve_function(cred, cert_callback);
 428 #else
 429                         gnutls_certificate_client_set_retrieve_function(cred, cert_callback);
 430 #endif
 431                 }
 432
 433                 /** Sets the trusted CA and the certificate revocation list
 434                  * to use when verifying certificates
 435                  */
 436                 void SetCA(std::auto_ptr<X509CertList>& certlist, std::auto_ptr<X509CRL>& CRL)
 437                 {
 438                         // Do nothing if certlist is NULL
 439                         if (certlist.get())
 440                         {
 441                                 int ret = gnutls_certificate_set_x509_trust(cred, certlist->raw(), certlist->size());
 442                                 ThrowOnError(ret, "gnutls_certificate_set_x509_trust() failed");
 443
 444                                 if (CRL.get())
 445                                 {
 446                                         ret = gnutls_certificate_set_x509_crl(cred, &CRL->get(), 1);
 447                                         ThrowOnError(ret, "gnutls_certificate_set_x509_crl() failed");
 448                                 }
 449
 450                                 trustedca = certlist;
 451                                 crl = CRL;
 452                         }
 453                 }
 454         };
 455
 456         class Profile : public refcountbase
 457         {
 458                 /** Name of this profile
 459                  */
 460                 const std::string name;
 461
 462                 /** X509 certificate(s) and key
 463                  */
 464                 X509Credentials x509cred;
 465
 466                 /** The minimum length in bits for the DH prime to be accepted as a client
 467                  */
 468                 unsigned int min_dh_bits;
 469
 470                 /** Hashing algorithm to use when generating certificate fingerprints
 471                  */
 472                 Hash hash;
 473
 474                 /** Priorities for ciphers, compression methods, etc.
 475                  */
 476                 Priority priority;
 477
 478                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 479                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 480                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL)
 481                         : name(profilename)
 482                         , x509cred(certstr, keystr)
 483                         , min_dh_bits(mindh)
 484                         , hash(hashstr)
 485                         , priority(priostr)
 486                 {
 487                         x509cred.SetDH(DH);
 488                         x509cred.SetCA(CA, CRL);
 489                 }
 490
 491                 static std::string ReadFile(const std::string& filename)
 492                 {
 493                         FileReader reader(filename);
 494                         std::string ret = reader.GetString();
 495                         if (ret.empty())
 496                                 throw Exception("Cannot read file " + filename);
 497                         return ret;
 498                 }
 499
 500          public:
 501                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 502                 {
 503                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 504                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 505
 506                         std::auto_ptr<DHParams> dh;
 507                         int gendh = tag->getInt("gendh");
 508                         if (gendh)
 509                         {
 510                                 gendh = (gendh < 1024 ? 1024 : gendh);
 511                                 dh = DHParams::Generate(gendh);
 512                         }
 513                         else
 514                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 515
 516                         // Use default priority string if this tag does not specify one
 517                         std::string priostr = tag->getString("priority", "NORMAL");
 518                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 519                         std::string hashstr = tag->getString("hash", "md5");
 520
 521                         // Load trusted CA and revocation list, if set
 522                         std::auto_ptr<X509CertList> ca;
 523                         std::auto_ptr<X509CRL> crl;
 524                         std::string filename = tag->getString("cafile");
 525                         if (!filename.empty())
 526                         {
 527                                 ca.reset(new X509CertList(ReadFile(filename)));
 528
 529                                 filename = tag->getString("crlfile");
 530                                 if (!filename.empty())
 531                                         crl.reset(new X509CRL(ReadFile(filename)));
 532                         }
 533
 534                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl);
 535                 }
 536
 537                 /** Set up the given session with the settings in this profile
 538                  */
 539                 void SetupSession(gnutls_session_t sess)
 540                 {
 541                         priority.SetupSession(sess);
 542                         x509cred.SetupSession(sess);
 543                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 544                 }
 545
 546                 const std::string& GetName() const { return name; }
 547                 X509Credentials& GetX509Credentials() { return x509cred; }
 548                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 549         };
 550 }
 551
 552 class GnuTLSIOHook : public SSLIOHook
 553 {
 554  private:
 555         gnutls_session_t sess;
 556         issl_status status;
 557         reference<GnuTLS::Profile> profile;
 558
 559         void InitSession(StreamSocket* user, bool me_server)
 560         {
 561                 gnutls_init(&sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 562
 563                 profile->SetupSession(sess);
 564                 gnutls_transport_set_ptr(sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 565                 gnutls_transport_set_push_function(sess, gnutls_push_wrapper);
 566                 gnutls_transport_set_pull_function(sess, gnutls_pull_wrapper);
 567
 568                 if (me_server)
 569                         gnutls_certificate_server_set_request(sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 570         }
 571
 572         void CloseSession()
 573         {
 574                 if (this->sess)
 575                 {
 576                         gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 577                         gnutls_deinit(this->sess);
 578                 }
 579                 sess = NULL;
 580                 certificate = NULL;
 581                 status = ISSL_NONE;
 582         }
 583
 584         bool Handshake(StreamSocket* user)
 585         {
 586                 int ret = gnutls_handshake(this->sess);
 587
 588                 if (ret < 0)
 589                 {
 590                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 591                         {
 592                                 // Handshake needs resuming later, read() or write() would have blocked.
 593
 594                                 if (gnutls_record_get_direction(this->sess) == 0)
 595                                 {
 596                                         // gnutls_handshake() wants to read() again.
 597                                         this->status = ISSL_HANDSHAKING_READ;
 598                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 599                                 }
 600                                 else
 601                                 {
 602                                         // gnutls_handshake() wants to write() again.
 603                                         this->status = ISSL_HANDSHAKING_WRITE;
 604                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 605                                 }
 606                         }
 607                         else
 608                         {
 609                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 610                                 CloseSession();
 611                                 this->status = ISSL_CLOSING;
 612                         }
 613
 614                         return false;
 615                 }
 616                 else
 617                 {
 618                         // Change the seesion state
 619                         this->status = ISSL_HANDSHAKEN;
 620
 621                         VerifyCertificate();
 622
 623                         // Finish writing, if any left
 624                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 625
 626                         return true;
 627                 }
 628         }
 629
 630         void VerifyCertificate()
 631         {
 632                 unsigned int certstatus;
 633                 const gnutls_datum_t* cert_list;
 634                 int ret;
 635                 unsigned int cert_list_size;
 636                 gnutls_x509_crt_t cert;
 637                 char str[512];
 638                 unsigned char digest[512];
 639                 size_t digest_size = sizeof(digest);
 640                 size_t name_size = sizeof(str);
 641                 ssl_cert* certinfo = new ssl_cert;
 642                 this->certificate = certinfo;
 643
 644                 /* This verification function uses the trusted CAs in the credentials
 645                  * structure. So you must have installed one or more CA certificates.
 646                  */
 647                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 648
 649                 if (ret < 0)
 650                 {
 651                         certinfo->error = std::string(gnutls_strerror(ret));
 652                         return;
 653                 }
 654
 655                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 656                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 657                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 658                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 659
 660                 /* Up to here the process is the same for X.509 certificates and
 661                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 662                  * be easily extended to work with openpgp keys as well.
 663                  */
 664                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 665                 {
 666                         certinfo->error = "No X509 keys sent";
 667                         return;
 668                 }
 669
 670                 ret = gnutls_x509_crt_init(&cert);
 671                 if (ret < 0)
 672                 {
 673                         certinfo->error = gnutls_strerror(ret);
 674                         return;
 675                 }
 676
 677                 cert_list_size = 0;
 678                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 679                 if (cert_list == NULL)
 680                 {
 681                         certinfo->error = "No certificate was found";
 682                         goto info_done_dealloc;
 683                 }
 684
 685                 /* This is not a real world example, since we only check the first
 686                  * certificate in the given chain.
 687                  */
 688
 689                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 690                 if (ret < 0)
 691                 {
 692                         certinfo->error = gnutls_strerror(ret);
 693                         goto info_done_dealloc;
 694                 }
 695
 696                 gnutls_x509_crt_get_dn(cert, str, &name_size);
 697                 certinfo->dn = str;
 698
 699                 gnutls_x509_crt_get_issuer_dn(cert, str, &name_size);
 700                 certinfo->issuer = str;
 701
 702                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 703                 {
 704                         certinfo->error = gnutls_strerror(ret);
 705                 }
 706                 else
 707                 {
 708                         certinfo->fingerprint = BinToHex(digest, digest_size);
 709                 }
 710
 711                 /* Beware here we do not check for errors.
 712                  */
 713                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 714                 {
 715                         certinfo->error = "Not activated, or expired certificate";
 716                 }
 717
 718 info_done_dealloc:
 719                 gnutls_x509_crt_deinit(cert);
 720         }
 721
 722         static const char* UnknownIfNULL(const char* str)
 723         {
 724                 return str ? str : "UNKNOWN";
 725         }
 726
 727         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 728         {
 729                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 730 #ifdef _WIN32
 731                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 732 #endif
 733
 734                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 735                 {
 736 #ifdef _WIN32
 737                         gnutls_transport_set_errno(session->sess, EAGAIN);
 738 #else
 739                         errno = EAGAIN;
 740 #endif
 741                         return -1;
 742                 }
 743
 744                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 745
 746 #ifdef _WIN32
 747                 if (rv < 0)
 748                 {
 749                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 750                          * and then set errno appropriately.
 751                          * The gnutls library may also have a different errno variable than us, see
 752                          * gnutls_transport_set_errno(3).
 753                          */
 754                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 755                 }
 756 #endif
 757
 758                 if (rv < (int)size)
 759                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 760                 return rv;
 761         }
 762
 763         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 764         {
 765                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 766 #ifdef _WIN32
 767                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 768 #endif
 769
 770                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 771                 {
 772 #ifdef _WIN32
 773                         gnutls_transport_set_errno(session->sess, EAGAIN);
 774 #else
 775                         errno = EAGAIN;
 776 #endif
 777                         return -1;
 778                 }
 779
 780                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 781
 782 #ifdef _WIN32
 783                 if (rv < 0)
 784                 {
 785                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 786                          * and then set errno appropriately.
 787                          * The gnutls library may also have a different errno variable than us, see
 788                          * gnutls_transport_set_errno(3).
 789                          */
 790                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 791                 }
 792 #endif
 793
 794                 if (rv < (int)size)
 795                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 796                 return rv;
 797         }
 798
 799  public:
 800         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool outbound, const reference<GnuTLS::Profile>& sslprofile)
 801                 : SSLIOHook(hookprov)
 802                 , sess(NULL)
 803                 , status(ISSL_NONE)
 804                 , profile(sslprofile)
 805         {
 806                 InitSession(sock, outbound);
 807                 sock->AddIOHook(this);
 808                 Handshake(sock);
 809         }
 810
 811         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 812         {
 813                 CloseSession();
 814         }
 815
 816         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 817         {
 818                 if (!this->sess)
 819                 {
 820                         CloseSession();
 821                         user->SetError("No SSL session");
 822                         return -1;
 823                 }
 824
 825                 if (this->status == ISSL_HANDSHAKING_READ || this->status == ISSL_HANDSHAKING_WRITE)
 826                 {
 827                         // The handshake isn't finished, try to finish it.
 828
 829                         if (!Handshake(user))
 830                         {
 831                                 if (this->status != ISSL_CLOSING)
 832                                         return 0;
 833                                 return -1;
 834                         }
 835                 }
 836
 837                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 838
 839                 if (this->status == ISSL_HANDSHAKEN)
 840                 {
 841                         char* buffer = ServerInstance->GetReadBuffer();
 842                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 843                         int ret = gnutls_record_recv(this->sess, buffer, bufsiz);
 844                         if (ret > 0)
 845                         {
 846                                 recvq.append(buffer, ret);
 847                                 return 1;
 848                         }
 849                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 850                         {
 851                                 return 0;
 852                         }
 853                         else if (ret == 0)
 854                         {
 855                                 user->SetError("Connection closed");
 856                                 CloseSession();
 857                                 return -1;
 858                         }
 859                         else
 860                         {
 861                                 user->SetError(gnutls_strerror(ret));
 862                                 CloseSession();
 863                                 return -1;
 864                         }
 865                 }
 866                 else if (this->status == ISSL_CLOSING)
 867                         return -1;
 868
 869                 return 0;
 870         }
 871
 872         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 873         {
 874                 if (!this->sess)
 875                 {
 876                         CloseSession();
 877                         user->SetError("No SSL session");
 878                         return -1;
 879                 }
 880
 881                 if (this->status == ISSL_HANDSHAKING_WRITE || this->status == ISSL_HANDSHAKING_READ)
 882                 {
 883                         // The handshake isn't finished, try to finish it.
 884                         Handshake(user);
 885                         if (this->status != ISSL_CLOSING)
 886                                 return 0;
 887                         return -1;
 888                 }
 889
 890                 int ret = 0;
 891
 892                 if (this->status == ISSL_HANDSHAKEN)
 893                 {
 894                         ret = gnutls_record_send(this->sess, sendq.data(), sendq.length());
 895
 896                         if (ret == (int)sendq.length())
 897                         {
 898                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 899                                 return 1;
 900                         }
 901                         else if (ret > 0)
 902                         {
 903                                 sendq = sendq.substr(ret);
 904                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 905                                 return 0;
 906                         }
 907                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 908                         {
 909                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 910                                 return 0;
 911                         }
 912                         else // (ret < 0)
 913                         {
 914                                 user->SetError(gnutls_strerror(ret));
 915                                 CloseSession();
 916                                 return -1;
 917                         }
 918                 }
 919
 920                 return 0;
 921         }
 922
 923         void TellCiphersAndFingerprint(LocalUser* user)
 924         {
 925                 if (sess)
 926                 {
 927                         std::string text = "*** You are connected using SSL cipher '";
 928
 929                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 930                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 931                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 932
 933                         if (!certificate->fingerprint.empty())
 934                                 text += " and your SSL fingerprint is " + certificate->fingerprint;
 935
 936                         user->WriteNotice(text);
 937                 }
 938         }
 939
 940         GnuTLS::Profile* GetProfile() { return profile; }
 941 };
 942
 943 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)
 944 {
 945 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
 946         st->type = GNUTLS_CRT_X509;
 947 #else
 948         st->cert_type = GNUTLS_CRT_X509;
 949         st->key_type = GNUTLS_PRIVKEY_X509;
 950 #endif
 951         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
 952         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
 953
 954         st->ncerts = cred.certs.size();
 955         st->cert.x509 = cred.certs.raw();
 956         st->key.x509 = cred.key.get();
 957         st->deinit_all = 0;
 958
 959         return 0;
 960 }
 961
 962 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
 963 {
 964         reference<GnuTLS::Profile> profile;
 965
 966  public:
 967         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
 968                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
 969                 , profile(prof)
 970         {
 971                 ServerInstance->Modules->AddService(*this);
 972         }
 973
 974         ~GnuTLSIOHookProvider()
 975         {
 976                 ServerInstance->Modules->DelService(*this);
 977         }
 978
 979         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 980         {
 981                 new GnuTLSIOHook(this, sock, true, profile);
 982         }
 983
 984         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
 985         {
 986                 new GnuTLSIOHook(this, sock, false, profile);
 987         }
 988 };
 989
 990 class ModuleSSLGnuTLS : public Module
 991 {
 992         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
 993
 994         // First member of the class, gets constructed first and destructed last
 995         GnuTLS::Init libinit;
 996         RandGen randhandler;
 997         ProfileList profiles;
 998
 999         void ReadProfiles()
1000         {
1001                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1002                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1003                 // avoiding unpleasant situations where no new SSL connections are possible.
1004                 ProfileList newprofiles;
1005
1006                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1007                 if (tags.first == tags.second)
1008                 {
1009                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1010                         const std::string defname = "gnutls";
1011                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1012                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1013
1014                         try
1015                         {
1016                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1017                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1018                         }
1019                         catch (CoreException& ex)
1020                         {
1021                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1022                         }
1023                 }
1024
1025                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1026                 {
1027                         ConfigTag* tag = i->second;
1028                         if (tag->getString("provider") != "gnutls")
1029                                 continue;
1030
1031                         std::string name = tag->getString("name");
1032                         if (name.empty())
1033                         {
1034                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1035                                 continue;
1036                         }
1037
1038                         reference<GnuTLS::Profile> profile;
1039                         try
1040                         {
1041                                 profile = GnuTLS::Profile::Create(name, tag);
1042                         }
1043                         catch (CoreException& ex)
1044                         {
1045                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1046                         }
1047
1048                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1049                 }
1050
1051                 // New profiles are ok, begin using them
1052                 // Old profiles are deleted when their refcount drops to zero
1053                 profiles.swap(newprofiles);
1054         }
1055
1056  public:
1057         ModuleSSLGnuTLS()
1058         {
1059 #ifndef GNUTLS_HAS_RND
1060                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1061 #endif
1062         }
1063
1064         void init() CXX11_OVERRIDE
1065         {
1066                 ReadProfiles();
1067                 ServerInstance->GenRandom = &randhandler;
1068         }
1069
1070         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1071         {
1072                 if(param != "ssl")
1073                         return;
1074
1075                 try
1076                 {
1077                         ReadProfiles();
1078                 }
1079                 catch (ModuleException& ex)
1080                 {
1081                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1082                 }
1083         }
1084
1085         ~ModuleSSLGnuTLS()
1086         {
1087                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1088         }
1089
1090         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1091         {
1092                 if(target_type == TYPE_USER)
1093                 {
1094                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1095
1096                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1097                         {
1098                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1099                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1100                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1101                         }
1102                 }
1103         }
1104
1105         Version GetVersion() CXX11_OVERRIDE
1106         {
1107                 return Version("Provides SSL support for clients", VF_VENDOR);
1108         }
1109
1110         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1111         {
1112                 IOHook* hook = user->eh.GetIOHook();
1113                 if (hook && hook->prov->creator == this)
1114                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1115         }
1116 };
1117
1118 MODULE_INIT(ModuleSSLGnuTLS)