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 #ifndef GNUTLS_VERSION_NUMBER
  39 #define GNUTLS_VERSION_NUMBER LIBGNUTLS_VERSION_NUMBER
  40 #endif
  41
  42 // Check if the GnuTLS library is at least version major.minor.patch
  43 #define INSPIRCD_GNUTLS_HAS_VERSION(major, minor, patch) (GNUTLS_VERSION_NUMBER >= ((major << 16) | (minor << 8) | patch))
  44
  45 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 9, 8)
  46 #define GNUTLS_HAS_MAC_GET_ID
  47 #include <gnutls/crypto.h>
  48 #endif
  49
  50 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 12, 0)
  51 # define GNUTLS_HAS_RND
  52 #else
  53 # include <gcrypt.h>
  54 #endif
  55
  56 #ifdef _WIN32
  57 # pragma comment(lib, "libgnutls-28.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 // These don't exist in older GnuTLS versions
  64 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 1, 7)
  65 #define GNUTLS_NEW_PRIO_API
  66 #endif
  67
  68 #if (!INSPIRCD_GNUTLS_HAS_VERSION(2, 0, 0))
  69 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  70 typedef gnutls_dh_params_t gnutls_dh_params;
  71 #endif
  72
  73 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_HANDSHAKEN };
  74
  75 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 12, 0)
  76 #define GNUTLS_NEW_CERT_CALLBACK_API
  77 typedef gnutls_retr2_st cert_cb_last_param_type;
  78 #else
  79 typedef gnutls_retr_st cert_cb_last_param_type;
  80 #endif
  81
  82 #if INSPIRCD_GNUTLS_HAS_VERSION(3, 3, 5)
  83 #define INSPIRCD_GNUTLS_HAS_RECV_PACKET
  84 #endif
  85
  86 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 99, 0)
  87 // The second parameter of gnutls_init() has changed in 2.99.0 from gnutls_connection_end_t to unsigned int
  88 // (it became a general flags parameter) and the enum has been deprecated and generates a warning on use.
  89 typedef unsigned int inspircd_gnutls_session_init_flags_t;
  90 #else
  91 typedef gnutls_connection_end_t inspircd_gnutls_session_init_flags_t;
  92 #endif
  93
  94 class RandGen : public HandlerBase2<void, char*, size_t>
  95 {
  96  public:
  97         void Call(char* buffer, size_t len)
  98         {
  99 #ifdef GNUTLS_HAS_RND
 100                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
 101 #else
 102                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
 103 #endif
 104         }
 105 };
 106
 107 namespace GnuTLS
 108 {
 109         class Init
 110         {
 111          public:
 112                 Init() { gnutls_global_init(); }
 113                 ~Init() { gnutls_global_deinit(); }
 114         };
 115
 116         class Exception : public ModuleException
 117         {
 118          public:
 119                 Exception(const std::string& reason)
 120                         : ModuleException(reason) { }
 121         };
 122
 123         void ThrowOnError(int errcode, const char* msg)
 124         {
 125                 if (errcode < 0)
 126                 {
 127                         std::string reason = msg;
 128                         reason.append(" :").append(gnutls_strerror(errcode));
 129                         throw Exception(reason);
 130                 }
 131         }
 132
 133         /** Used to create a gnutls_datum_t* from a std::string
 134          */
 135         class Datum
 136         {
 137                 gnutls_datum_t datum;
 138
 139          public:
 140                 Datum(const std::string& dat)
 141                 {
 142                         datum.data = (unsigned char*)dat.data();
 143                         datum.size = static_cast<unsigned int>(dat.length());
 144                 }
 145
 146                 const gnutls_datum_t* get() const { return &datum; }
 147         };
 148
 149         class Hash
 150         {
 151                 gnutls_digest_algorithm_t hash;
 152
 153          public:
 154                 // Nothing to deallocate, constructor may throw freely
 155                 Hash(const std::string& hashname)
 156                 {
 157                         // As older versions of gnutls can't do this, let's disable it where needed.
 158 #ifdef GNUTLS_HAS_MAC_GET_ID
 159                         // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 160                         // There is no gnutls_dig_get_id() at the moment, but it may come later
 161                         hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 162                         if (hash == GNUTLS_DIG_UNKNOWN)
 163                                 throw Exception("Unknown hash type " + hashname);
 164
 165                         // Check if the user is giving us something that is a valid MAC but not digest
 166                         gnutls_hash_hd_t is_digest;
 167                         if (gnutls_hash_init(&is_digest, hash) < 0)
 168                                 throw Exception("Unknown hash type " + hashname);
 169                         gnutls_hash_deinit(is_digest, NULL);
 170 #else
 171                         if (hashname == "md5")
 172                                 hash = GNUTLS_DIG_MD5;
 173                         else if (hashname == "sha1")
 174                                 hash = GNUTLS_DIG_SHA1;
 175 #ifdef INSPIRCD_GNUTLS_ENABLE_SHA256_FINGERPRINT
 176                         else if (hashname == "sha256")
 177                                 hash = GNUTLS_DIG_SHA256;
 178 #endif
 179                         else
 180                                 throw Exception("Unknown hash type " + hashname);
 181 #endif
 182                 }
 183
 184                 gnutls_digest_algorithm_t get() const { return hash; }
 185         };
 186
 187         class DHParams
 188         {
 189                 gnutls_dh_params_t dh_params;
 190
 191                 DHParams()
 192                 {
 193                         ThrowOnError(gnutls_dh_params_init(&dh_params), "gnutls_dh_params_init() failed");
 194                 }
 195
 196          public:
 197                 /** Import */
 198                 static std::auto_ptr<DHParams> Import(const std::string& dhstr)
 199                 {
 200                         std::auto_ptr<DHParams> dh(new DHParams);
 201                         int ret = gnutls_dh_params_import_pkcs3(dh->dh_params, Datum(dhstr).get(), GNUTLS_X509_FMT_PEM);
 202                         ThrowOnError(ret, "Unable to import DH params");
 203                         return dh;
 204                 }
 205
 206                 /** Generate */
 207                 static std::auto_ptr<DHParams> Generate(unsigned int bits)
 208                 {
 209                         std::auto_ptr<DHParams> dh(new DHParams);
 210                         ThrowOnError(gnutls_dh_params_generate2(dh->dh_params, bits), "Unable to generate DH params");
 211                         return dh;
 212                 }
 213
 214                 ~DHParams()
 215                 {
 216                         gnutls_dh_params_deinit(dh_params);
 217                 }
 218
 219                 const gnutls_dh_params_t& get() const { return dh_params; }
 220         };
 221
 222         class X509Key
 223         {
 224                 /** Ensure that the key is deinited in case the constructor of X509Key throws
 225                  */
 226                 class RAIIKey
 227                 {
 228                  public:
 229                         gnutls_x509_privkey_t key;
 230
 231                         RAIIKey()
 232                         {
 233                                 ThrowOnError(gnutls_x509_privkey_init(&key), "gnutls_x509_privkey_init() failed");
 234                         }
 235
 236                         ~RAIIKey()
 237                         {
 238                                 gnutls_x509_privkey_deinit(key);
 239                         }
 240                 } key;
 241
 242          public:
 243                 /** Import */
 244                 X509Key(const std::string& keystr)
 245                 {
 246                         int ret = gnutls_x509_privkey_import(key.key, Datum(keystr).get(), GNUTLS_X509_FMT_PEM);
 247                         ThrowOnError(ret, "Unable to import private key");
 248                 }
 249
 250                 gnutls_x509_privkey_t& get() { return key.key; }
 251         };
 252
 253         class X509CertList
 254         {
 255                 std::vector<gnutls_x509_crt_t> certs;
 256
 257          public:
 258                 /** Import */
 259                 X509CertList(const std::string& certstr)
 260                 {
 261                         unsigned int certcount = 3;
 262                         certs.resize(certcount);
 263                         Datum datum(certstr);
 264
 265                         int ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 266                         if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 267                         {
 268                                 // the buffer wasn't big enough to hold all certs but gnutls changed certcount to the number of available certs,
 269                                 // try again with a bigger buffer
 270                                 certs.resize(certcount);
 271                                 ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 272                         }
 273
 274                         ThrowOnError(ret, "Unable to load certificates");
 275
 276                         // Resize the vector to the actual number of certs because we rely on its size being correct
 277                         // when deallocating the certs
 278                         certs.resize(certcount);
 279                 }
 280
 281                 ~X509CertList()
 282                 {
 283                         for (std::vector<gnutls_x509_crt_t>::iterator i = certs.begin(); i != certs.end(); ++i)
 284                                 gnutls_x509_crt_deinit(*i);
 285                 }
 286
 287                 gnutls_x509_crt_t* raw() { return &certs[0]; }
 288                 unsigned int size() const { return certs.size(); }
 289         };
 290
 291         class X509CRL : public refcountbase
 292         {
 293                 class RAIICRL
 294                 {
 295                  public:
 296                         gnutls_x509_crl_t crl;
 297
 298                         RAIICRL()
 299                         {
 300                                 ThrowOnError(gnutls_x509_crl_init(&crl), "gnutls_x509_crl_init() failed");
 301                         }
 302
 303                         ~RAIICRL()
 304                         {
 305                                 gnutls_x509_crl_deinit(crl);
 306                         }
 307                 } crl;
 308
 309          public:
 310                 /** Import */
 311                 X509CRL(const std::string& crlstr)
 312                 {
 313                         int ret = gnutls_x509_crl_import(get(), Datum(crlstr).get(), GNUTLS_X509_FMT_PEM);
 314                         ThrowOnError(ret, "Unable to load certificate revocation list");
 315                 }
 316
 317                 gnutls_x509_crl_t& get() { return crl.crl; }
 318         };
 319
 320 #ifdef GNUTLS_NEW_PRIO_API
 321         class Priority
 322         {
 323                 gnutls_priority_t priority;
 324
 325          public:
 326                 Priority(const std::string& priorities)
 327                 {
 328                         // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 329                         // If the user did not supply anything then the string is already set to "NORMAL"
 330                         const char* priocstr = priorities.c_str();
 331                         const char* prioerror;
 332
 333                         int ret = gnutls_priority_init(&priority, priocstr, &prioerror);
 334                         if (ret < 0)
 335                         {
 336                                 // gnutls did not understand the user supplied string
 337                                 throw Exception("Unable to initialize priorities to \"" + priorities + "\": " + gnutls_strerror(ret) + " Syntax error at position " + ConvToStr((unsigned int) (prioerror - priocstr)));
 338                         }
 339                 }
 340
 341                 ~Priority()
 342                 {
 343                         gnutls_priority_deinit(priority);
 344                 }
 345
 346                 void SetupSession(gnutls_session_t sess)
 347                 {
 348                         gnutls_priority_set(sess, priority);
 349                 }
 350         };
 351 #else
 352         /** Dummy class, used when gnutls_priority_set() is not available
 353          */
 354         class Priority
 355         {
 356          public:
 357                 Priority(const std::string& priorities)
 358                 {
 359                         if (priorities != "NORMAL")
 360                                 throw Exception("You've set a non-default priority string, but GnuTLS lacks support for it");
 361                 }
 362
 363                 static void SetupSession(gnutls_session_t sess)
 364                 {
 365                         // Always set the default priorities
 366                         gnutls_set_default_priority(sess);
 367                 }
 368         };
 369 #endif
 370
 371         class CertCredentials
 372         {
 373                 /** DH parameters associated with these credentials
 374                  */
 375                 std::auto_ptr<DHParams> dh;
 376
 377          protected:
 378                 gnutls_certificate_credentials_t cred;
 379
 380          public:
 381                 CertCredentials()
 382                 {
 383                         ThrowOnError(gnutls_certificate_allocate_credentials(&cred), "Cannot allocate certificate credentials");
 384                 }
 385
 386                 ~CertCredentials()
 387                 {
 388                         gnutls_certificate_free_credentials(cred);
 389                 }
 390
 391                 /** Associates these credentials with the session
 392                  */
 393                 void SetupSession(gnutls_session_t sess)
 394                 {
 395                         gnutls_credentials_set(sess, GNUTLS_CRD_CERTIFICATE, cred);
 396                 }
 397
 398                 /** Set the given DH parameters to be used with these credentials
 399                  */
 400                 void SetDH(std::auto_ptr<DHParams>& DH)
 401                 {
 402                         dh = DH;
 403                         gnutls_certificate_set_dh_params(cred, dh->get());
 404                 }
 405         };
 406
 407         class X509Credentials : public CertCredentials
 408         {
 409                 /** Private key
 410                  */
 411                 X509Key key;
 412
 413                 /** Certificate list, presented to the peer
 414                  */
 415                 X509CertList certs;
 416
 417                 /** Trusted CA, may be NULL
 418                  */
 419                 std::auto_ptr<X509CertList> trustedca;
 420
 421                 /** Certificate revocation list, may be NULL
 422                  */
 423                 std::auto_ptr<X509CRL> crl;
 424
 425                 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);
 426
 427          public:
 428                 X509Credentials(const std::string& certstr, const std::string& keystr)
 429                         : key(keystr)
 430                         , certs(certstr)
 431                 {
 432                         // Throwing is ok here, the destructor of Credentials is called in that case
 433                         int ret = gnutls_certificate_set_x509_key(cred, certs.raw(), certs.size(), key.get());
 434                         ThrowOnError(ret, "Unable to set cert/key pair");
 435
 436 #ifdef GNUTLS_NEW_CERT_CALLBACK_API
 437                         gnutls_certificate_set_retrieve_function(cred, cert_callback);
 438 #else
 439                         gnutls_certificate_client_set_retrieve_function(cred, cert_callback);
 440 #endif
 441                 }
 442
 443                 /** Sets the trusted CA and the certificate revocation list
 444                  * to use when verifying certificates
 445                  */
 446                 void SetCA(std::auto_ptr<X509CertList>& certlist, std::auto_ptr<X509CRL>& CRL)
 447                 {
 448                         // Do nothing if certlist is NULL
 449                         if (certlist.get())
 450                         {
 451                                 int ret = gnutls_certificate_set_x509_trust(cred, certlist->raw(), certlist->size());
 452                                 ThrowOnError(ret, "gnutls_certificate_set_x509_trust() failed");
 453
 454                                 if (CRL.get())
 455                                 {
 456                                         ret = gnutls_certificate_set_x509_crl(cred, &CRL->get(), 1);
 457                                         ThrowOnError(ret, "gnutls_certificate_set_x509_crl() failed");
 458                                 }
 459
 460                                 trustedca = certlist;
 461                                 crl = CRL;
 462                         }
 463                 }
 464         };
 465
 466         class DataReader
 467         {
 468                 int retval;
 469 #ifdef INSPIRCD_GNUTLS_HAS_RECV_PACKET
 470                 gnutls_packet_t packet;
 471
 472          public:
 473                 DataReader(gnutls_session_t sess)
 474                 {
 475                         // Using the packet API avoids the final copy of the data which GnuTLS does if we supply
 476                         // our own buffer. Instead, we get the buffer containing the data from GnuTLS and copy it
 477                         // to the recvq directly from there in appendto().
 478                         retval = gnutls_record_recv_packet(sess, &packet);
 479                 }
 480
 481                 void appendto(std::string& recvq)
 482                 {
 483                         // Copy data from GnuTLS buffers to recvq
 484                         gnutls_datum_t datum;
 485                         gnutls_packet_get(packet, &datum, NULL);
 486                         recvq.append(reinterpret_cast<const char*>(datum.data), datum.size);
 487
 488                         gnutls_packet_deinit(packet);
 489                 }
 490 #else
 491                 char* const buffer;
 492
 493          public:
 494                 DataReader(gnutls_session_t sess)
 495                         : buffer(ServerInstance->GetReadBuffer())
 496                 {
 497                         // Read data from GnuTLS buffers into ReadBuffer
 498                         retval = gnutls_record_recv(sess, buffer, ServerInstance->Config->NetBufferSize);
 499                 }
 500
 501                 void appendto(std::string& recvq)
 502                 {
 503                         // Copy data from ReadBuffer to recvq
 504                         recvq.append(buffer, retval);
 505                 }
 506 #endif
 507
 508                 int ret() const { return retval; }
 509         };
 510
 511         class Profile : public refcountbase
 512         {
 513                 /** Name of this profile
 514                  */
 515                 const std::string name;
 516
 517                 /** X509 certificate(s) and key
 518                  */
 519                 X509Credentials x509cred;
 520
 521                 /** The minimum length in bits for the DH prime to be accepted as a client
 522                  */
 523                 unsigned int min_dh_bits;
 524
 525                 /** Hashing algorithm to use when generating certificate fingerprints
 526                  */
 527                 Hash hash;
 528
 529                 /** Priorities for ciphers, compression methods, etc.
 530                  */
 531                 Priority priority;
 532
 533                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 534                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 535                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL)
 536                         : name(profilename)
 537                         , x509cred(certstr, keystr)
 538                         , min_dh_bits(mindh)
 539                         , hash(hashstr)
 540                         , priority(priostr)
 541                 {
 542                         x509cred.SetDH(DH);
 543                         x509cred.SetCA(CA, CRL);
 544                 }
 545
 546                 static std::string ReadFile(const std::string& filename)
 547                 {
 548                         FileReader reader(filename);
 549                         std::string ret = reader.GetString();
 550                         if (ret.empty())
 551                                 throw Exception("Cannot read file " + filename);
 552                         return ret;
 553                 }
 554
 555          public:
 556                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 557                 {
 558                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 559                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 560
 561                         std::auto_ptr<DHParams> dh;
 562                         int gendh = tag->getInt("gendh");
 563                         if (gendh)
 564                         {
 565                                 gendh = (gendh < 1024 ? 1024 : gendh);
 566                                 dh = DHParams::Generate(gendh);
 567                         }
 568                         else
 569                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 570
 571                         // Use default priority string if this tag does not specify one
 572                         std::string priostr = tag->getString("priority", "NORMAL");
 573                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 574                         std::string hashstr = tag->getString("hash", "md5");
 575
 576                         // Load trusted CA and revocation list, if set
 577                         std::auto_ptr<X509CertList> ca;
 578                         std::auto_ptr<X509CRL> crl;
 579                         std::string filename = tag->getString("cafile");
 580                         if (!filename.empty())
 581                         {
 582                                 ca.reset(new X509CertList(ReadFile(filename)));
 583
 584                                 filename = tag->getString("crlfile");
 585                                 if (!filename.empty())
 586                                         crl.reset(new X509CRL(ReadFile(filename)));
 587                         }
 588
 589                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl);
 590                 }
 591
 592                 /** Set up the given session with the settings in this profile
 593                  */
 594                 void SetupSession(gnutls_session_t sess)
 595                 {
 596                         priority.SetupSession(sess);
 597                         x509cred.SetupSession(sess);
 598                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 599
 600                         // Request client certificate if we are a server, no-op if we're a client
 601                         gnutls_certificate_server_set_request(sess, GNUTLS_CERT_REQUEST);
 602                 }
 603
 604                 const std::string& GetName() const { return name; }
 605                 X509Credentials& GetX509Credentials() { return x509cred; }
 606                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 607         };
 608 }
 609
 610 class GnuTLSIOHook : public SSLIOHook
 611 {
 612  private:
 613         gnutls_session_t sess;
 614         issl_status status;
 615         reference<GnuTLS::Profile> profile;
 616
 617         void CloseSession()
 618         {
 619                 if (this->sess)
 620                 {
 621                         gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 622                         gnutls_deinit(this->sess);
 623                 }
 624                 sess = NULL;
 625                 certificate = NULL;
 626                 status = ISSL_NONE;
 627         }
 628
 629         // Returns 1 if handshake succeeded, 0 if it is still in progress, -1 if it failed
 630         int Handshake(StreamSocket* user)
 631         {
 632                 int ret = gnutls_handshake(this->sess);
 633
 634                 if (ret < 0)
 635                 {
 636                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 637                         {
 638                                 // Handshake needs resuming later, read() or write() would have blocked.
 639                                 this->status = ISSL_HANDSHAKING;
 640
 641                                 if (gnutls_record_get_direction(this->sess) == 0)
 642                                 {
 643                                         // gnutls_handshake() wants to read() again.
 644                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 645                                 }
 646                                 else
 647                                 {
 648                                         // gnutls_handshake() wants to write() again.
 649                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 650                                 }
 651
 652                                 return 0;
 653                         }
 654                         else
 655                         {
 656                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 657                                 CloseSession();
 658                                 return -1;
 659                         }
 660                 }
 661                 else
 662                 {
 663                         // Change the seesion state
 664                         this->status = ISSL_HANDSHAKEN;
 665
 666                         VerifyCertificate();
 667
 668                         // Finish writing, if any left
 669                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 670
 671                         return 1;
 672                 }
 673         }
 674
 675         void VerifyCertificate()
 676         {
 677                 unsigned int certstatus;
 678                 const gnutls_datum_t* cert_list;
 679                 int ret;
 680                 unsigned int cert_list_size;
 681                 gnutls_x509_crt_t cert;
 682                 char str[512];
 683                 unsigned char digest[512];
 684                 size_t digest_size = sizeof(digest);
 685                 size_t name_size = sizeof(str);
 686                 ssl_cert* certinfo = new ssl_cert;
 687                 this->certificate = certinfo;
 688
 689                 /* This verification function uses the trusted CAs in the credentials
 690                  * structure. So you must have installed one or more CA certificates.
 691                  */
 692                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 693
 694                 if (ret < 0)
 695                 {
 696                         certinfo->error = std::string(gnutls_strerror(ret));
 697                         return;
 698                 }
 699
 700                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 701                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 702                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 703                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 704
 705                 /* Up to here the process is the same for X.509 certificates and
 706                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 707                  * be easily extended to work with openpgp keys as well.
 708                  */
 709                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 710                 {
 711                         certinfo->error = "No X509 keys sent";
 712                         return;
 713                 }
 714
 715                 ret = gnutls_x509_crt_init(&cert);
 716                 if (ret < 0)
 717                 {
 718                         certinfo->error = gnutls_strerror(ret);
 719                         return;
 720                 }
 721
 722                 cert_list_size = 0;
 723                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 724                 if (cert_list == NULL)
 725                 {
 726                         certinfo->error = "No certificate was found";
 727                         goto info_done_dealloc;
 728                 }
 729
 730                 /* This is not a real world example, since we only check the first
 731                  * certificate in the given chain.
 732                  */
 733
 734                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 735                 if (ret < 0)
 736                 {
 737                         certinfo->error = gnutls_strerror(ret);
 738                         goto info_done_dealloc;
 739                 }
 740
 741                 if (gnutls_x509_crt_get_dn(cert, str, &name_size) == 0)
 742                 {
 743                         std::string& dn = certinfo->dn;
 744                         dn = str;
 745                         // Make sure there are no chars in the string that we consider invalid
 746                         if (dn.find_first_of("\r\n") != std::string::npos)
 747                                 dn.clear();
 748                 }
 749
 750                 name_size = sizeof(str);
 751                 if (gnutls_x509_crt_get_issuer_dn(cert, str, &name_size) == 0)
 752                 {
 753                         std::string& issuer = certinfo->issuer;
 754                         issuer = str;
 755                         if (issuer.find_first_of("\r\n") != std::string::npos)
 756                                 issuer.clear();
 757                 }
 758
 759                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 760                 {
 761                         certinfo->error = gnutls_strerror(ret);
 762                 }
 763                 else
 764                 {
 765                         certinfo->fingerprint = BinToHex(digest, digest_size);
 766                 }
 767
 768                 /* Beware here we do not check for errors.
 769                  */
 770                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 771                 {
 772                         certinfo->error = "Not activated, or expired certificate";
 773                 }
 774
 775 info_done_dealloc:
 776                 gnutls_x509_crt_deinit(cert);
 777         }
 778
 779         // Returns 1 if application I/O should proceed, 0 if it must wait for the underlying protocol to progress, -1 on fatal error
 780         int PrepareIO(StreamSocket* sock)
 781         {
 782                 if (status == ISSL_HANDSHAKEN)
 783                         return 1;
 784                 else if (status == ISSL_HANDSHAKING)
 785                 {
 786                         // The handshake isn't finished, try to finish it
 787                         return Handshake(sock);
 788                 }
 789
 790                 CloseSession();
 791                 sock->SetError("No SSL session");
 792                 return -1;
 793         }
 794
 795         static const char* UnknownIfNULL(const char* str)
 796         {
 797                 return str ? str : "UNKNOWN";
 798         }
 799
 800         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 801         {
 802                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 803 #ifdef _WIN32
 804                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 805 #endif
 806
 807                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 808                 {
 809 #ifdef _WIN32
 810                         gnutls_transport_set_errno(session->sess, EAGAIN);
 811 #else
 812                         errno = EAGAIN;
 813 #endif
 814                         return -1;
 815                 }
 816
 817                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 818
 819 #ifdef _WIN32
 820                 if (rv < 0)
 821                 {
 822                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 823                          * and then set errno appropriately.
 824                          * The gnutls library may also have a different errno variable than us, see
 825                          * gnutls_transport_set_errno(3).
 826                          */
 827                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 828                 }
 829 #endif
 830
 831                 if (rv < (int)size)
 832                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 833                 return rv;
 834         }
 835
 836         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 837         {
 838                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 839 #ifdef _WIN32
 840                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 841 #endif
 842
 843                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 844                 {
 845 #ifdef _WIN32
 846                         gnutls_transport_set_errno(session->sess, EAGAIN);
 847 #else
 848                         errno = EAGAIN;
 849 #endif
 850                         return -1;
 851                 }
 852
 853                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 854
 855 #ifdef _WIN32
 856                 if (rv < 0)
 857                 {
 858                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 859                          * and then set errno appropriately.
 860                          * The gnutls library may also have a different errno variable than us, see
 861                          * gnutls_transport_set_errno(3).
 862                          */
 863                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 864                 }
 865 #endif
 866
 867                 if (rv < (int)size)
 868                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 869                 return rv;
 870         }
 871
 872  public:
 873         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, inspircd_gnutls_session_init_flags_t flags, const reference<GnuTLS::Profile>& sslprofile)
 874                 : SSLIOHook(hookprov)
 875                 , sess(NULL)
 876                 , status(ISSL_NONE)
 877                 , profile(sslprofile)
 878         {
 879                 gnutls_init(&sess, flags);
 880                 gnutls_transport_set_ptr(sess, reinterpret_cast<gnutls_transport_ptr_t>(sock));
 881                 gnutls_transport_set_push_function(sess, gnutls_push_wrapper);
 882                 gnutls_transport_set_pull_function(sess, gnutls_pull_wrapper);
 883                 profile->SetupSession(sess);
 884
 885                 sock->AddIOHook(this);
 886                 Handshake(sock);
 887         }
 888
 889         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 890         {
 891                 CloseSession();
 892         }
 893
 894         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 895         {
 896                 // Finish handshake if needed
 897                 int prepret = PrepareIO(user);
 898                 if (prepret <= 0)
 899                         return prepret;
 900
 901                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 902                 {
 903                         GnuTLS::DataReader reader(sess);
 904                         int ret = reader.ret();
 905                         if (ret > 0)
 906                         {
 907                                 reader.appendto(recvq);
 908                                 return 1;
 909                         }
 910                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 911                         {
 912                                 return 0;
 913                         }
 914                         else if (ret == 0)
 915                         {
 916                                 user->SetError("Connection closed");
 917                                 CloseSession();
 918                                 return -1;
 919                         }
 920                         else
 921                         {
 922                                 user->SetError(gnutls_strerror(ret));
 923                                 CloseSession();
 924                                 return -1;
 925                         }
 926                 }
 927         }
 928
 929         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 930         {
 931                 // Finish handshake if needed
 932                 int prepret = PrepareIO(user);
 933                 if (prepret <= 0)
 934                         return prepret;
 935
 936                 // Session is ready for transferring application data
 937                 int ret = 0;
 938
 939                 {
 940                         ret = gnutls_record_send(this->sess, sendq.data(), sendq.length());
 941
 942                         if (ret == (int)sendq.length())
 943                         {
 944                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 945                                 return 1;
 946                         }
 947                         else if (ret > 0)
 948                         {
 949                                 sendq.erase(0, ret);
 950                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 951                                 return 0;
 952                         }
 953                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 954                         {
 955                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 956                                 return 0;
 957                         }
 958                         else // (ret < 0)
 959                         {
 960                                 user->SetError(gnutls_strerror(ret));
 961                                 CloseSession();
 962                                 return -1;
 963                         }
 964                 }
 965         }
 966
 967         void TellCiphersAndFingerprint(LocalUser* user)
 968         {
 969                 if (sess)
 970                 {
 971                         std::string text = "*** You are connected using SSL cipher '";
 972                         GetCiphersuite(text);
 973                         text += '\'';
 974                         if (!certificate->fingerprint.empty())
 975                                 text += " and your SSL certificate fingerprint is " + certificate->fingerprint;
 976
 977                         user->WriteNotice(text);
 978                 }
 979         }
 980
 981         void GetCiphersuite(std::string& out) const
 982         {
 983                 out.append(UnknownIfNULL(gnutls_protocol_get_name(gnutls_protocol_get_version(sess)))).push_back('-');
 984                 out.append(UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)))).push_back('-');
 985                 out.append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).push_back('-');
 986                 out.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess))));
 987         }
 988
 989         GnuTLS::Profile* GetProfile() { return profile; }
 990 };
 991
 992 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)
 993 {
 994 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
 995         st->type = GNUTLS_CRT_X509;
 996 #else
 997         st->cert_type = GNUTLS_CRT_X509;
 998         st->key_type = GNUTLS_PRIVKEY_X509;
 999 #endif
1000         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
1001         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
1002
1003         st->ncerts = cred.certs.size();
1004         st->cert.x509 = cred.certs.raw();
1005         st->key.x509 = cred.key.get();
1006         st->deinit_all = 0;
1007
1008         return 0;
1009 }
1010
1011 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
1012 {
1013         reference<GnuTLS::Profile> profile;
1014
1015  public:
1016         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
1017                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
1018                 , profile(prof)
1019         {
1020                 ServerInstance->Modules->AddService(*this);
1021         }
1022
1023         ~GnuTLSIOHookProvider()
1024         {
1025                 ServerInstance->Modules->DelService(*this);
1026         }
1027
1028         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
1029         {
1030                 new GnuTLSIOHook(this, sock, GNUTLS_SERVER, profile);
1031         }
1032
1033         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
1034         {
1035                 new GnuTLSIOHook(this, sock, GNUTLS_CLIENT, profile);
1036         }
1037 };
1038
1039 class ModuleSSLGnuTLS : public Module
1040 {
1041         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
1042
1043         // First member of the class, gets constructed first and destructed last
1044         GnuTLS::Init libinit;
1045         RandGen randhandler;
1046         ProfileList profiles;
1047
1048         void ReadProfiles()
1049         {
1050                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1051                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1052                 // avoiding unpleasant situations where no new SSL connections are possible.
1053                 ProfileList newprofiles;
1054
1055                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1056                 if (tags.first == tags.second)
1057                 {
1058                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1059                         const std::string defname = "gnutls";
1060                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1061                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1062
1063                         try
1064                         {
1065                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1066                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1067                         }
1068                         catch (CoreException& ex)
1069                         {
1070                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1071                         }
1072                 }
1073
1074                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1075                 {
1076                         ConfigTag* tag = i->second;
1077                         if (tag->getString("provider") != "gnutls")
1078                                 continue;
1079
1080                         std::string name = tag->getString("name");
1081                         if (name.empty())
1082                         {
1083                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1084                                 continue;
1085                         }
1086
1087                         reference<GnuTLS::Profile> profile;
1088                         try
1089                         {
1090                                 profile = GnuTLS::Profile::Create(name, tag);
1091                         }
1092                         catch (CoreException& ex)
1093                         {
1094                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1095                         }
1096
1097                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1098                 }
1099
1100                 // New profiles are ok, begin using them
1101                 // Old profiles are deleted when their refcount drops to zero
1102                 profiles.swap(newprofiles);
1103         }
1104
1105  public:
1106         ModuleSSLGnuTLS()
1107         {
1108 #ifndef GNUTLS_HAS_RND
1109                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1110 #endif
1111         }
1112
1113         void init() CXX11_OVERRIDE
1114         {
1115                 ReadProfiles();
1116                 ServerInstance->GenRandom = &randhandler;
1117         }
1118
1119         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1120         {
1121                 if(param != "ssl")
1122                         return;
1123
1124                 try
1125                 {
1126                         ReadProfiles();
1127                 }
1128                 catch (ModuleException& ex)
1129                 {
1130                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1131                 }
1132         }
1133
1134         ~ModuleSSLGnuTLS()
1135         {
1136                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1137         }
1138
1139         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1140         {
1141                 if(target_type == TYPE_USER)
1142                 {
1143                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1144
1145                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1146                         {
1147                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1148                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1149                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1150                         }
1151                 }
1152         }
1153
1154         Version GetVersion() CXX11_OVERRIDE
1155         {
1156                 return Version("Provides SSL support for clients", VF_VENDOR);
1157         }
1158
1159         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1160         {
1161                 IOHook* hook = user->eh.GetIOHook();
1162                 if (hook && hook->prov->creator == this)
1163                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1164         }
1165 };
1166
1167 MODULE_INIT(ModuleSSLGnuTLS)