src/modules/extra/m_ssl_gnutls.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2008 John Brooks <john.brooks@dereferenced.net>
   6  *   Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   8  *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
   9  *
  10  * This file is part of InspIRCd.  InspIRCd is free software: you can
  11  * redistribute it and/or modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation, version 2.
  13  *
  14  * This program is distributed in the hope that it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  16  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23
  24 #include "inspircd.h"
  25 #include <gnutls/gnutls.h>
  26 #include <gnutls/x509.h>
  27 #include "modules/ssl.h"
  28 #include "modules/cap.h"
  29 #include <memory>
  30
  31 #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))
  32 #define GNUTLS_HAS_MAC_GET_ID
  33 #include <gnutls/crypto.h>
  34 #endif
  35
  36 #if (GNUTLS_VERSION_MAJOR > 2 || GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 12)
  37 # define GNUTLS_HAS_RND
  38 #else
  39 # include <gcrypt.h>
  40 #endif
  41
  42 #ifdef _WIN32
  43 # pragma comment(lib, "libgnutls.lib")
  44 # pragma comment(lib, "libgcrypt.lib")
  45 # pragma comment(lib, "libgpg-error.lib")
  46 # pragma comment(lib, "user32.lib")
  47 # pragma comment(lib, "advapi32.lib")
  48 # pragma comment(lib, "libgcc.lib")
  49 # pragma comment(lib, "libmingwex.lib")
  50 # pragma comment(lib, "gdi32.lib")
  51 #endif
  52
  53 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") eval("print `libgcrypt-config --cflags | tr -d \r` if `pkg-config --modversion gnutls 2>/dev/null | tr -d \r` lt '2.12'") -Wno-pedantic */
  54 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") eval("print `libgcrypt-config --libs | tr -d \r` if `pkg-config --modversion gnutls 2>/dev/null | tr -d \r` lt '2.12'") */
  55
  56 #ifndef GNUTLS_VERSION_MAJOR
  57 #define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
  58 #define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
  59 #define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
  60 #endif
  61
  62 // These don't exist in older GnuTLS versions
  63 #if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 1) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 1 && GNUTLS_VERSION_PATCH >= 7))
  64 #define GNUTLS_NEW_PRIO_API
  65 #endif
  66
  67 #if(GNUTLS_VERSION_MAJOR < 2)
  68 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  69 typedef gnutls_dh_params_t gnutls_dh_params;
  70 #endif
  71
  72 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  73
  74 #if (GNUTLS_VERSION_MAJOR > 2 || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR >= 12))
  75 #define GNUTLS_NEW_CERT_CALLBACK_API
  76 typedef gnutls_retr2_st cert_cb_last_param_type;
  77 #else
  78 typedef gnutls_retr_st cert_cb_last_param_type;
  79 #endif
  80
  81 class RandGen : public HandlerBase2<void, char*, size_t>
  82 {
  83  public:
  84         RandGen() {}
  85         void Call(char* buffer, size_t len)
  86         {
  87 #ifdef GNUTLS_HAS_RND
  88                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
  89 #else
  90                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  91 #endif
  92         }
  93 };
  94
  95 namespace GnuTLS
  96 {
  97         class Init
  98         {
  99          public:
 100                 Init() { gnutls_global_init(); }
 101                 ~Init() { gnutls_global_deinit(); }
 102         };
 103
 104         class Exception : public ModuleException
 105         {
 106          public:
 107                 Exception(const std::string& reason)
 108                         : ModuleException(reason) { }
 109         };
 110
 111         void ThrowOnError(int errcode, const char* msg)
 112         {
 113                 if (errcode < 0)
 114                 {
 115                         std::string reason = msg;
 116                         reason.append(" :").append(gnutls_strerror(errcode));
 117                         throw Exception(reason);
 118                 }
 119         }
 120
 121         /** Used to create a gnutls_datum_t* from a std::string
 122          */
 123         class Datum
 124         {
 125                 gnutls_datum_t datum;
 126
 127          public:
 128                 Datum(const std::string& dat)
 129                 {
 130                         datum.data = (unsigned char*)dat.data();
 131                         datum.size = static_cast<unsigned int>(dat.length());
 132                 }
 133
 134                 const gnutls_datum_t* get() const { return &datum; }
 135         };
 136
 137         class Hash
 138         {
 139                 gnutls_digest_algorithm_t hash;
 140
 141          public:
 142                 // Nothing to deallocate, constructor may throw freely
 143                 Hash(const std::string& hashname)
 144                 {
 145                         // As older versions of gnutls can't do this, let's disable it where needed.
 146 #ifdef GNUTLS_HAS_MAC_GET_ID
 147                         // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 148                         // There is no gnutls_dig_get_id() at the moment, but it may come later
 149                         hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 150                         if (hash == GNUTLS_DIG_UNKNOWN)
 151                                 throw Exception("Unknown hash type " + hashname);
 152
 153                         // Check if the user is giving us something that is a valid MAC but not digest
 154                         gnutls_hash_hd_t is_digest;
 155                         if (gnutls_hash_init(&is_digest, hash) < 0)
 156                                 throw Exception("Unknown hash type " + hashname);
 157                         gnutls_hash_deinit(is_digest, NULL);
 158 #else
 159                         if (hashname == "md5")
 160                                 hash = GNUTLS_DIG_MD5;
 161                         else if (hashname == "sha1")
 162                                 hash = GNUTLS_DIG_SHA1;
 163                         else
 164                                 throw Exception("Unknown hash type " + hashname);
 165 #endif
 166                 }
 167
 168                 gnutls_digest_algorithm_t get() const { return hash; }
 169         };
 170
 171         class DHParams
 172         {
 173                 gnutls_dh_params_t dh_params;
 174
 175                 DHParams()
 176                 {
 177                         ThrowOnError(gnutls_dh_params_init(&dh_params), "gnutls_dh_params_init() failed");
 178                 }
 179
 180          public:
 181                 /** Import */
 182                 static std::auto_ptr<DHParams> Import(const std::string& dhstr)
 183                 {
 184                         std::auto_ptr<DHParams> dh(new DHParams);
 185                         int ret = gnutls_dh_params_import_pkcs3(dh->dh_params, Datum(dhstr).get(), GNUTLS_X509_FMT_PEM);
 186                         ThrowOnError(ret, "Unable to import DH params");
 187                         return dh;
 188                 }
 189
 190                 /** Generate */
 191                 static std::auto_ptr<DHParams> Generate(unsigned int bits)
 192                 {
 193                         std::auto_ptr<DHParams> dh(new DHParams);
 194                         ThrowOnError(gnutls_dh_params_generate2(dh->dh_params, bits), "Unable to generate DH params");
 195                         return dh;
 196                 }
 197
 198                 ~DHParams()
 199                 {
 200                         gnutls_dh_params_deinit(dh_params);
 201                 }
 202
 203                 const gnutls_dh_params_t& get() const { return dh_params; }
 204         };
 205
 206         class X509Key
 207         {
 208                 /** Ensure that the key is deinited in case the constructor of X509Key throws
 209                  */
 210                 class RAIIKey
 211                 {
 212                  public:
 213                         gnutls_x509_privkey_t key;
 214
 215                         RAIIKey()
 216                         {
 217                                 ThrowOnError(gnutls_x509_privkey_init(&key), "gnutls_x509_privkey_init() failed");
 218                         }
 219
 220                         ~RAIIKey()
 221                         {
 222                                 gnutls_x509_privkey_deinit(key);
 223                         }
 224                 } key;
 225
 226          public:
 227                 /** Import */
 228                 X509Key(const std::string& keystr)
 229                 {
 230                         int ret = gnutls_x509_privkey_import(key.key, Datum(keystr).get(), GNUTLS_X509_FMT_PEM);
 231                         ThrowOnError(ret, "Unable to import private key");
 232                 }
 233
 234                 gnutls_x509_privkey_t& get() { return key.key; }
 235         };
 236
 237         class X509CertList
 238         {
 239                 std::vector<gnutls_x509_crt_t> certs;
 240
 241          public:
 242                 /** Import */
 243                 X509CertList(const std::string& certstr)
 244                 {
 245                         unsigned int certcount = 3;
 246                         certs.resize(certcount);
 247                         Datum datum(certstr);
 248
 249                         int ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 250                         if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 251                         {
 252                                 // the buffer wasn't big enough to hold all certs but gnutls changed certcount to the number of available certs,
 253                                 // try again with a bigger buffer
 254                                 certs.resize(certcount);
 255                                 ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 256                         }
 257
 258                         ThrowOnError(ret, "Unable to load certificates");
 259
 260                         // Resize the vector to the actual number of certs because we rely on its size being correct
 261                         // when deallocating the certs
 262                         certs.resize(certcount);
 263                 }
 264
 265                 ~X509CertList()
 266                 {
 267                         for (std::vector<gnutls_x509_crt_t>::iterator i = certs.begin(); i != certs.end(); ++i)
 268                                 gnutls_x509_crt_deinit(*i);
 269                 }
 270
 271                 gnutls_x509_crt_t* raw() { return &certs[0]; }
 272                 unsigned int size() const { return certs.size(); }
 273         };
 274
 275         class X509CRL : public refcountbase
 276         {
 277                 class RAIICRL
 278                 {
 279                  public:
 280                         gnutls_x509_crl_t crl;
 281
 282                         RAIICRL()
 283                         {
 284                                 ThrowOnError(gnutls_x509_crl_init(&crl), "gnutls_x509_crl_init() failed");
 285                         }
 286
 287                         ~RAIICRL()
 288                         {
 289                                 gnutls_x509_crl_deinit(crl);
 290                         }
 291                 } crl;
 292
 293          public:
 294                 /** Import */
 295                 X509CRL(const std::string& crlstr)
 296                 {
 297                         int ret = gnutls_x509_crl_import(get(), Datum(crlstr).get(), GNUTLS_X509_FMT_PEM);
 298                         ThrowOnError(ret, "Unable to load certificate revocation list");
 299                 }
 300
 301                 gnutls_x509_crl_t& get() { return crl.crl; }
 302         };
 303
 304 #ifdef GNUTLS_NEW_PRIO_API
 305         class Priority
 306         {
 307                 gnutls_priority_t priority;
 308
 309          public:
 310                 Priority(const std::string& priorities)
 311                 {
 312                         // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 313                         // If the user did not supply anything then the string is already set to "NORMAL"
 314                         const char* priocstr = priorities.c_str();
 315                         const char* prioerror;
 316
 317                         int ret = gnutls_priority_init(&priority, priocstr, &prioerror);
 318                         if (ret < 0)
 319                         {
 320                                 // gnutls did not understand the user supplied string
 321                                 throw Exception("Unable to initialize priorities to \"" + priorities + "\": " + gnutls_strerror(ret) + " Syntax error at position " + ConvToStr((unsigned int) (prioerror - priocstr)));
 322                         }
 323                 }
 324
 325                 ~Priority()
 326                 {
 327                         gnutls_priority_deinit(priority);
 328                 }
 329
 330                 void SetupSession(gnutls_session_t sess)
 331                 {
 332                         gnutls_priority_set(sess, priority);
 333                 }
 334         };
 335 #else
 336         /** Dummy class, used when gnutls_priority_set() is not available
 337          */
 338         class Priority
 339         {
 340          public:
 341                 Priority(const std::string& priorities)
 342                 {
 343                         if (priorities != "NORMAL")
 344                                 throw Exception("You've set a non-default priority string, but GnuTLS lacks support for it");
 345                 }
 346
 347                 static void SetupSession(gnutls_session_t sess)
 348                 {
 349                         // Always set the default priorities
 350                         gnutls_set_default_priority(sess);
 351                 }
 352         };
 353 #endif
 354
 355         class CertCredentials
 356         {
 357                 /** DH parameters associated with these credentials
 358                  */
 359                 std::auto_ptr<DHParams> dh;
 360
 361          protected:
 362                 gnutls_certificate_credentials_t cred;
 363
 364          public:
 365                 CertCredentials()
 366                 {
 367                         ThrowOnError(gnutls_certificate_allocate_credentials(&cred), "Cannot allocate certificate credentials");
 368                 }
 369
 370                 ~CertCredentials()
 371                 {
 372                         gnutls_certificate_free_credentials(cred);
 373                 }
 374
 375                 /** Associates these credentials with the session
 376                  */
 377                 void SetupSession(gnutls_session_t sess)
 378                 {
 379                         gnutls_credentials_set(sess, GNUTLS_CRD_CERTIFICATE, cred);
 380                 }
 381
 382                 /** Set the given DH parameters to be used with these credentials
 383                  */
 384                 void SetDH(std::auto_ptr<DHParams>& DH)
 385                 {
 386                         dh = DH;
 387                         gnutls_certificate_set_dh_params(cred, dh->get());
 388                 }
 389         };
 390
 391         class X509Credentials : public CertCredentials
 392         {
 393                 /** Private key
 394                  */
 395                 X509Key key;
 396
 397                 /** Certificate list, presented to the peer
 398                  */
 399                 X509CertList certs;
 400
 401                 /** Trusted CA, may be NULL
 402                  */
 403                 std::auto_ptr<X509CertList> trustedca;
 404
 405                 /** Certificate revocation list, may be NULL
 406                  */
 407                 std::auto_ptr<X509CRL> crl;
 408
 409                 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);
 410
 411          public:
 412                 X509Credentials(const std::string& certstr, const std::string& keystr)
 413                         : key(keystr)
 414                         , certs(certstr)
 415                 {
 416                         // Throwing is ok here, the destructor of Credentials is called in that case
 417                         int ret = gnutls_certificate_set_x509_key(cred, certs.raw(), certs.size(), key.get());
 418                         ThrowOnError(ret, "Unable to set cert/key pair");
 419
 420 #ifdef GNUTLS_NEW_CERT_CALLBACK_API
 421                         gnutls_certificate_set_retrieve_function(cred, cert_callback);
 422 #else
 423                         gnutls_certificate_client_set_retrieve_function(cred, cert_callback);
 424 #endif
 425                 }
 426
 427                 /** Sets the trusted CA and the certificate revocation list
 428                  * to use when verifying certificates
 429                  */
 430                 void SetCA(std::auto_ptr<X509CertList>& certlist, std::auto_ptr<X509CRL>& CRL)
 431                 {
 432                         // Do nothing if certlist is NULL
 433                         if (certlist.get())
 434                         {
 435                                 int ret = gnutls_certificate_set_x509_trust(cred, certlist->raw(), certlist->size());
 436                                 ThrowOnError(ret, "gnutls_certificate_set_x509_trust() failed");
 437
 438                                 if (CRL.get())
 439                                 {
 440                                         ret = gnutls_certificate_set_x509_crl(cred, &CRL->get(), 1);
 441                                         ThrowOnError(ret, "gnutls_certificate_set_x509_crl() failed");
 442                                 }
 443
 444                                 trustedca = certlist;
 445                                 crl = CRL;
 446                         }
 447                 }
 448         };
 449
 450         class Profile : public refcountbase
 451         {
 452                 /** Name of this profile
 453                  */
 454                 const std::string name;
 455
 456                 /** X509 certificate(s) and key
 457                  */
 458                 X509Credentials x509cred;
 459
 460                 /** The minimum length in bits for the DH prime to be accepted as a client
 461                  */
 462                 unsigned int min_dh_bits;
 463
 464                 /** Hashing algorithm to use when generating certificate fingerprints
 465                  */
 466                 Hash hash;
 467
 468                 /** Priorities for ciphers, compression methods, etc.
 469                  */
 470                 Priority priority;
 471
 472                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 473                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 474                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL)
 475                         : name(profilename)
 476                         , x509cred(certstr, keystr)
 477                         , min_dh_bits(mindh)
 478                         , hash(hashstr)
 479                         , priority(priostr)
 480                 {
 481                         x509cred.SetDH(DH);
 482                         x509cred.SetCA(CA, CRL);
 483                 }
 484
 485                 static std::string ReadFile(const std::string& filename)
 486                 {
 487                         FileReader reader(filename);
 488                         std::string ret = reader.GetString();
 489                         if (ret.empty())
 490                                 throw Exception("Cannot read file " + filename);
 491                         return ret;
 492                 }
 493
 494          public:
 495                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 496                 {
 497                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 498                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 499
 500                         std::auto_ptr<DHParams> dh;
 501                         int gendh = tag->getInt("gendh");
 502                         if (gendh)
 503                         {
 504                                 gendh = (gendh < 1024 ? 1024 : gendh);
 505                                 dh = DHParams::Generate(gendh);
 506                         }
 507                         else
 508                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 509
 510                         // Use default priority string if this tag does not specify one
 511                         std::string priostr = tag->getString("priority", "NORMAL");
 512                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 513                         std::string hashstr = tag->getString("hash", "md5");
 514
 515                         // Load trusted CA and revocation list, if set
 516                         std::auto_ptr<X509CertList> ca;
 517                         std::auto_ptr<X509CRL> crl;
 518                         std::string filename = tag->getString("cafile");
 519                         if (!filename.empty())
 520                         {
 521                                 ca.reset(new X509CertList(ReadFile(filename)));
 522
 523                                 filename = tag->getString("crlfile");
 524                                 if (!filename.empty())
 525                                         crl.reset(new X509CRL(ReadFile(filename)));
 526                         }
 527
 528                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl);
 529                 }
 530
 531                 /** Set up the given session with the settings in this profile
 532                  */
 533                 void SetupSession(gnutls_session_t sess)
 534                 {
 535                         priority.SetupSession(sess);
 536                         x509cred.SetupSession(sess);
 537                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 538                 }
 539
 540                 const std::string& GetName() const { return name; }
 541                 X509Credentials& GetX509Credentials() { return x509cred; }
 542                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 543         };
 544 }
 545
 546 /** Represents an SSL user's extra data
 547  */
 548 class issl_session
 549 {
 550 public:
 551         StreamSocket* socket;
 552         gnutls_session_t sess;
 553         issl_status status;
 554         reference<ssl_cert> cert;
 555         reference<GnuTLS::Profile> profile;
 556
 557         issl_session() : socket(NULL), sess(NULL) {}
 558 };
 559
 560 class GnuTLSIOHook : public SSLIOHook
 561 {
 562  private:
 563         void InitSession(StreamSocket* user, bool me_server)
 564         {
 565                 issl_session* session = &sessions[user->GetFd()];
 566
 567                 gnutls_init(&session->sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 568                 session->socket = user;
 569
 570                 session->profile->SetupSession(session->sess);
 571                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(session));
 572                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 573                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 574
 575                 if (me_server)
 576                         gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 577
 578                 Handshake(session, user);
 579         }
 580
 581         void CloseSession(issl_session* session)
 582         {
 583                 if (session->sess)
 584                 {
 585                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 586                         gnutls_deinit(session->sess);
 587                 }
 588                 session->socket = NULL;
 589                 session->sess = NULL;
 590                 session->cert = NULL;
 591                 session->profile = NULL;
 592                 session->status = ISSL_NONE;
 593         }
 594
 595         bool Handshake(issl_session* session, StreamSocket* user)
 596         {
 597                 int ret = gnutls_handshake(session->sess);
 598
 599                 if (ret < 0)
 600                 {
 601                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 602                         {
 603                                 // Handshake needs resuming later, read() or write() would have blocked.
 604
 605                                 if(gnutls_record_get_direction(session->sess) == 0)
 606                                 {
 607                                         // gnutls_handshake() wants to read() again.
 608                                         session->status = ISSL_HANDSHAKING_READ;
 609                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 610                                 }
 611                                 else
 612                                 {
 613                                         // gnutls_handshake() wants to write() again.
 614                                         session->status = ISSL_HANDSHAKING_WRITE;
 615                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 616                                 }
 617                         }
 618                         else
 619                         {
 620                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 621                                 CloseSession(session);
 622                                 session->status = ISSL_CLOSING;
 623                         }
 624
 625                         return false;
 626                 }
 627                 else
 628                 {
 629                         // Change the seesion state
 630                         session->status = ISSL_HANDSHAKEN;
 631
 632                         VerifyCertificate(session,user);
 633
 634                         // Finish writing, if any left
 635                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 636
 637                         return true;
 638                 }
 639         }
 640
 641         void VerifyCertificate(issl_session* session, StreamSocket* user)
 642         {
 643                 if (!session->sess || !user)
 644                         return;
 645
 646                 unsigned int status;
 647                 const gnutls_datum_t* cert_list;
 648                 int ret;
 649                 unsigned int cert_list_size;
 650                 gnutls_x509_crt_t cert;
 651                 char str[512];
 652                 unsigned char digest[512];
 653                 size_t digest_size = sizeof(digest);
 654                 size_t name_size = sizeof(str);
 655                 ssl_cert* certinfo = new ssl_cert;
 656                 session->cert = certinfo;
 657
 658                 /* This verification function uses the trusted CAs in the credentials
 659                  * structure. So you must have installed one or more CA certificates.
 660                  */
 661                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 662
 663                 if (ret < 0)
 664                 {
 665                         certinfo->error = std::string(gnutls_strerror(ret));
 666                         return;
 667                 }
 668
 669                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 670                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 671                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 672                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 673
 674                 /* Up to here the process is the same for X.509 certificates and
 675                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 676                  * be easily extended to work with openpgp keys as well.
 677                  */
 678                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 679                 {
 680                         certinfo->error = "No X509 keys sent";
 681                         return;
 682                 }
 683
 684                 ret = gnutls_x509_crt_init(&cert);
 685                 if (ret < 0)
 686                 {
 687                         certinfo->error = gnutls_strerror(ret);
 688                         return;
 689                 }
 690
 691                 cert_list_size = 0;
 692                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 693                 if (cert_list == NULL)
 694                 {
 695                         certinfo->error = "No certificate was found";
 696                         goto info_done_dealloc;
 697                 }
 698
 699                 /* This is not a real world example, since we only check the first
 700                  * certificate in the given chain.
 701                  */
 702
 703                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 704                 if (ret < 0)
 705                 {
 706                         certinfo->error = gnutls_strerror(ret);
 707                         goto info_done_dealloc;
 708                 }
 709
 710                 gnutls_x509_crt_get_dn(cert, str, &name_size);
 711                 certinfo->dn = str;
 712
 713                 gnutls_x509_crt_get_issuer_dn(cert, str, &name_size);
 714                 certinfo->issuer = str;
 715
 716                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, session->profile->GetHash(), digest, &digest_size)) < 0)
 717                 {
 718                         certinfo->error = gnutls_strerror(ret);
 719                 }
 720                 else
 721                 {
 722                         certinfo->fingerprint = BinToHex(digest, digest_size);
 723                 }
 724
 725                 /* Beware here we do not check for errors.
 726                  */
 727                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 728                 {
 729                         certinfo->error = "Not activated, or expired certificate";
 730                 }
 731
 732 info_done_dealloc:
 733                 gnutls_x509_crt_deinit(cert);
 734         }
 735
 736         static const char* UnknownIfNULL(const char* str)
 737         {
 738                 return str ? str : "UNKNOWN";
 739         }
 740
 741         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 742         {
 743                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 744                 if (session->socket->GetEventMask() & FD_READ_WILL_BLOCK)
 745                 {
 746 #ifdef _WIN32
 747                         gnutls_transport_set_errno(session->sess, EAGAIN);
 748 #else
 749                         errno = EAGAIN;
 750 #endif
 751                         return -1;
 752                 }
 753
 754                 int rv = ServerInstance->SE->Recv(session->socket, reinterpret_cast<char *>(buffer), size, 0);
 755
 756 #ifdef _WIN32
 757                 if (rv < 0)
 758                 {
 759                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 760                          * and then set errno appropriately.
 761                          * The gnutls library may also have a different errno variable than us, see
 762                          * gnutls_transport_set_errno(3).
 763                          */
 764                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 765                 }
 766 #endif
 767
 768                 if (rv < (int)size)
 769                         ServerInstance->SE->ChangeEventMask(session->socket, FD_READ_WILL_BLOCK);
 770                 return rv;
 771         }
 772
 773         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 774         {
 775                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 776                 if (session->socket->GetEventMask() & FD_WRITE_WILL_BLOCK)
 777                 {
 778 #ifdef _WIN32
 779                         gnutls_transport_set_errno(session->sess, EAGAIN);
 780 #else
 781                         errno = EAGAIN;
 782 #endif
 783                         return -1;
 784                 }
 785
 786                 int rv = ServerInstance->SE->Send(session->socket, reinterpret_cast<const char *>(buffer), size, 0);
 787
 788 #ifdef _WIN32
 789                 if (rv < 0)
 790                 {
 791                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 792                          * and then set errno appropriately.
 793                          * The gnutls library may also have a different errno variable than us, see
 794                          * gnutls_transport_set_errno(3).
 795                          */
 796                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 797                 }
 798 #endif
 799
 800                 if (rv < (int)size)
 801                         ServerInstance->SE->ChangeEventMask(session->socket, FD_WRITE_WILL_BLOCK);
 802                 return rv;
 803         }
 804
 805  public:
 806         issl_session* sessions;
 807
 808         GnuTLSIOHook(Module* parent)
 809                 : SSLIOHook(parent, "ssl/gnutls")
 810         {
 811                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 812         }
 813
 814         ~GnuTLSIOHook()
 815         {
 816                 delete[] sessions;
 817         }
 818
 819         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 820         {
 821                 issl_session* session = &sessions[user->GetFd()];
 822
 823                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 824                 if (session->sess)
 825                         return;
 826
 827                 InitSession(user, true);
 828         }
 829
 830         void OnStreamSocketConnect(StreamSocket* user) CXX11_OVERRIDE
 831         {
 832                 InitSession(user, false);
 833         }
 834
 835         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 836         {
 837                 CloseSession(&sessions[user->GetFd()]);
 838         }
 839
 840         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 841         {
 842                 issl_session* session = &sessions[user->GetFd()];
 843
 844                 if (!session->sess)
 845                 {
 846                         CloseSession(session);
 847                         user->SetError("No SSL session");
 848                         return -1;
 849                 }
 850
 851                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 852                 {
 853                         // The handshake isn't finished, try to finish it.
 854
 855                         if(!Handshake(session, user))
 856                         {
 857                                 if (session->status != ISSL_CLOSING)
 858                                         return 0;
 859                                 return -1;
 860                         }
 861                 }
 862
 863                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 864
 865                 if (session->status == ISSL_HANDSHAKEN)
 866                 {
 867                         char* buffer = ServerInstance->GetReadBuffer();
 868                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 869                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 870                         if (ret > 0)
 871                         {
 872                                 recvq.append(buffer, ret);
 873                                 return 1;
 874                         }
 875                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 876                         {
 877                                 return 0;
 878                         }
 879                         else if (ret == 0)
 880                         {
 881                                 user->SetError("Connection closed");
 882                                 CloseSession(session);
 883                                 return -1;
 884                         }
 885                         else
 886                         {
 887                                 user->SetError(gnutls_strerror(ret));
 888                                 CloseSession(session);
 889                                 return -1;
 890                         }
 891                 }
 892                 else if (session->status == ISSL_CLOSING)
 893                         return -1;
 894
 895                 return 0;
 896         }
 897
 898         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 899         {
 900                 issl_session* session = &sessions[user->GetFd()];
 901
 902                 if (!session->sess)
 903                 {
 904                         CloseSession(session);
 905                         user->SetError("No SSL session");
 906                         return -1;
 907                 }
 908
 909                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 910                 {
 911                         // The handshake isn't finished, try to finish it.
 912                         Handshake(session, user);
 913                         if (session->status != ISSL_CLOSING)
 914                                 return 0;
 915                         return -1;
 916                 }
 917
 918                 int ret = 0;
 919
 920                 if (session->status == ISSL_HANDSHAKEN)
 921                 {
 922                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 923
 924                         if (ret == (int)sendq.length())
 925                         {
 926                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 927                                 return 1;
 928                         }
 929                         else if (ret > 0)
 930                         {
 931                                 sendq = sendq.substr(ret);
 932                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 933                                 return 0;
 934                         }
 935                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 936                         {
 937                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 938                                 return 0;
 939                         }
 940                         else // (ret < 0)
 941                         {
 942                                 user->SetError(gnutls_strerror(ret));
 943                                 CloseSession(session);
 944                                 return -1;
 945                         }
 946                 }
 947
 948                 return 0;
 949         }
 950
 951         ssl_cert* GetCertificate(StreamSocket* sock) CXX11_OVERRIDE
 952         {
 953                 int fd = sock->GetFd();
 954                 issl_session* session = &sessions[fd];
 955                 return session->cert;
 956         }
 957
 958         void TellCiphersAndFingerprint(LocalUser* user)
 959         {
 960                 const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
 961                 if (sess)
 962                 {
 963                         std::string text = "*** You are connected using SSL cipher '";
 964
 965                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 966                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 967                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 968
 969                         ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 970                         if (!cert->fingerprint.empty())
 971                                 text += " and your SSL fingerprint is " + cert->fingerprint;
 972
 973                         user->WriteNotice(text);
 974                 }
 975         }
 976 };
 977
 978 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)
 979 {
 980 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
 981         st->type = GNUTLS_CRT_X509;
 982 #else
 983         st->cert_type = GNUTLS_CRT_X509;
 984         st->key_type = GNUTLS_PRIVKEY_X509;
 985 #endif
 986         issl_session* session = reinterpret_cast<issl_session*>(gnutls_transport_get_ptr(sess));
 987         GnuTLS::X509Credentials& cred = session->profile->GetX509Credentials();
 988
 989         st->ncerts = cred.certs.size();
 990         st->cert.x509 = cred.certs.raw();
 991         st->key.x509 = cred.key.get();
 992         st->deinit_all = 0;
 993
 994         return 0;
 995 }
 996
 997 class ModuleSSLGnuTLS : public Module
 998 {
 999         typedef std::vector<reference<GnuTLS::Profile> > ProfileList;
1000
1001         // First member of the class, gets constructed first and destructed last
1002         GnuTLS::Init libinit;
1003
1004         GnuTLSIOHook iohook;
1005
1006         std::string sslports;
1007
1008         RandGen randhandler;
1009         ProfileList profiles;
1010
1011         void ReadProfiles()
1012         {
1013                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1014                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1015                 // avoiding unpleasant situations where no new SSL connections are possible.
1016                 ProfileList newprofiles;
1017
1018                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1019                 if (tags.first == tags.second)
1020                 {
1021                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1022                         const std::string defname = "gnutls";
1023                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1024                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1025
1026                         try
1027                         {
1028                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1029                                 newprofiles.push_back(profile);
1030                         }
1031                         catch (CoreException& ex)
1032                         {
1033                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1034                         }
1035                 }
1036
1037                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1038                 {
1039                         ConfigTag* tag = i->second;
1040                         if (tag->getString("provider") != "gnutls")
1041                                 continue;
1042
1043                         std::string name = tag->getString("name");
1044                         if (name.empty())
1045                         {
1046                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1047                                 continue;
1048                         }
1049
1050                         reference<GnuTLS::Profile> profile;
1051                         try
1052                         {
1053                                 profile = GnuTLS::Profile::Create(name, tag);
1054                         }
1055                         catch (CoreException& ex)
1056                         {
1057                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1058                         }
1059
1060                         newprofiles.push_back(profile);
1061                 }
1062
1063                 // New profiles are ok, begin using them
1064                 // Old profiles are deleted when their refcount drops to zero
1065                 profiles.swap(newprofiles);
1066         }
1067
1068  public:
1069         ModuleSSLGnuTLS() : iohook(this)
1070         {
1071 #ifndef GNUTLS_HAS_RND
1072                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1073 #endif
1074         }
1075
1076         void init() CXX11_OVERRIDE
1077         {
1078                 ReadProfiles();
1079                 ServerInstance->GenRandom = &randhandler;
1080         }
1081
1082         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
1083         {
1084                 sslports.clear();
1085
1086                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
1087
1088                 if (Conf->getBool("showports", true))
1089                 {
1090                         sslports = Conf->getString("advertisedports");
1091                         if (!sslports.empty())
1092                                 return;
1093
1094                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
1095                         {
1096                                 ListenSocket* port = ServerInstance->ports[i];
1097                                 if (port->bind_tag->getString("ssl") != "gnutls")
1098                                         continue;
1099
1100                                 const std::string& portid = port->bind_desc;
1101                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Enabling SSL for port %s", portid.c_str());
1102
1103                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
1104                                 {
1105                                         /*
1106                                          * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
1107                                          * the IP:port in ISUPPORT.
1108                                          *
1109                                          * We used to advertise all ports seperated by a ';' char that matched the above criteria,
1110                                          * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
1111                                          * To solve this by default we now only display the first IP:port found and let the user
1112                                          * configure the exact value for the 005 token, if necessary.
1113                                          */
1114                                         sslports = portid;
1115                                         break;
1116                                 }
1117                         }
1118                 }
1119         }
1120
1121         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1122         {
1123                 if(param != "ssl")
1124                         return;
1125
1126                 try
1127                 {
1128                         ReadProfiles();
1129                 }
1130                 catch (ModuleException& ex)
1131                 {
1132                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1133                 }
1134         }
1135
1136         ~ModuleSSLGnuTLS()
1137         {
1138                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1139         }
1140
1141         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1142         {
1143                 if(target_type == TYPE_USER)
1144                 {
1145                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1146
1147                         if (user && user->eh.GetIOHook() == &iohook)
1148                         {
1149                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1150                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1151                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1152                         }
1153                 }
1154         }
1155
1156         Version GetVersion() CXX11_OVERRIDE
1157         {
1158                 return Version("Provides SSL support for clients", VF_VENDOR);
1159         }
1160
1161         void On005Numeric(std::map<std::string, std::string>& tokens) CXX11_OVERRIDE
1162         {
1163                 if (!sslports.empty())
1164                         tokens["SSL"] = sslports;
1165         }
1166
1167         void OnHookIO(StreamSocket* user, ListenSocket* lsb) CXX11_OVERRIDE
1168         {
1169                 if (!user->GetIOHook())
1170                 {
1171                         std::string profilename = lsb->bind_tag->getString("ssl");
1172                         for (ProfileList::const_iterator i = profiles.begin(); i != profiles.end(); ++i)
1173                         {
1174                                 if ((*i)->GetName() == profilename)
1175                                 {
1176                                         iohook.sessions[user->GetFd()].profile = *i;
1177                                         user->AddIOHook(&iohook);
1178                                         break;
1179                                 }
1180                         }
1181                 }
1182         }
1183
1184         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1185         {
1186                 if (user->eh.GetIOHook() == &iohook)
1187                         iohook.TellCiphersAndFingerprint(user);
1188         }
1189 };
1190
1191 MODULE_INIT(ModuleSSLGnuTLS)