src/modules/extra/m_ssl_openssl.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include <openssl/ssl.h>
  16 #include <openssl/err.h>
  17 #include "ssl.h"
  18
  19 #ifdef WINDOWS
  20 #pragma comment(lib, "libeay32MTd")
  21 #pragma comment(lib, "ssleay32MTd")
  22 #undef MAX_DESCRIPTORS
  23 #define MAX_DESCRIPTORS 10000
  24 #endif
  25
  26 /* $ModDesc: Provides SSL support for clients */
  27
  28 /* $LinkerFlags: if("USE_FREEBSD_BASE_SSL") -lssl -lcrypto */
  29 /* $CompileFlags: if(!"USE_FREEBSD_BASE_SSL") pkgconfversion("openssl","0.9.7") pkgconfincludes("openssl","/openssl/ssl.h","") */
  30 /* $LinkerFlags: if(!"USE_FREEBSD_BASE_SSL") rpath("pkg-config --libs openssl") pkgconflibs("openssl","/libssl.so","-lssl -lcrypto -ldl") */
  31
  32 /* $ModDep: transport.h */
  33 /* $NoPedantic */
  34 /* $CopyInstall: conf/key.pem $(CONPATH) */
  35 /* $CopyInstall: conf/cert.pem $(CONPATH) */
  36
  37
  38 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
  39
  40 static bool SelfSigned = false;
  41
  42 char* get_error()
  43 {
  44         return ERR_error_string(ERR_get_error(), NULL);
  45 }
  46
  47 static int error_callback(const char *str, size_t len, void *u);
  48
  49 /** Represents an SSL user's extra data
  50  */
  51 class issl_session
  52 {
  53 public:
  54         SSL* sess;
  55         issl_status status;
  56
  57         int fd;
  58         bool outbound;
  59         bool data_to_write;
  60
  61         issl_session()
  62         {
  63                 outbound = false;
  64                 data_to_write = false;
  65         }
  66 };
  67
  68 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
  69 {
  70         /* XXX: This will allow self signed certificates.
  71          * In the future if we want an option to not allow this,
  72          * we can just return preverify_ok here, and openssl
  73          * will boot off self-signed and invalid peer certs.
  74          */
  75         int ve = X509_STORE_CTX_get_error(ctx);
  76
  77         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
  78
  79         return 1;
  80 }
  81
  82 class ModuleSSLOpenSSL : public Module
  83 {
  84         int inbufsize;
  85         issl_session* sessions;
  86
  87         SSL_CTX* ctx;
  88         SSL_CTX* clictx;
  89
  90         char cipher[MAXBUF];
  91
  92         std::string keyfile;
  93         std::string certfile;
  94         std::string cafile;
  95         // std::string crlfile;
  96         std::string dhfile;
  97         std::string sslports;
  98
  99  public:
 100
 101         ModuleSSLOpenSSL()
 102         {
 103                 ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);
 104
 105                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 106
 107                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 108                 inbufsize = ServerInstance->Config->NetBufferSize;
 109
 110                 /* Global SSL library initialization*/
 111                 SSL_library_init();
 112                 SSL_load_error_strings();
 113
 114                 /* Build our SSL contexts:
 115                  * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
 116                  */
 117                 ctx = SSL_CTX_new( SSLv23_server_method() );
 118                 clictx = SSL_CTX_new( SSLv23_client_method() );
 119
 120                 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 121                 SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 122
 123                 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 124                 SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 125
 126                 // Needs the flag as it ignores a plain /rehash
 127                 OnModuleRehash(NULL,"ssl");
 128                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnHookIO };
 129                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 130         }
 131
 132         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 133         {
 134                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "openssl")
 135                 {
 136                         /* Hook the user with our module */
 137                         user->AddIOHook(this);
 138                 }
 139         }
 140
 141         void OnRehash(User* user)
 142         {
 143                 ConfigReader Conf;
 144
 145                 sslports.clear();
 146
 147                 for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 148                 {
 149                         ListenSocket* port = ServerInstance->ports[i];
 150                         if (port->bind_tag->getString("ssl") != "openssl")
 151                                 continue;
 152
 153                         std::string portid = port->bind_desc;
 154                         ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 155                         if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 156                                 sslports.append(portid).append(";");
 157                 }
 158
 159                 if (!sslports.empty())
 160                         sslports.erase(sslports.end() - 1);
 161         }
 162
 163         void OnModuleRehash(User* user, const std::string &param)
 164         {
 165                 if (param != "ssl")
 166                         return;
 167
 168                 OnRehash(user);
 169
 170                 ConfigReader Conf;
 171
 172                 cafile   = Conf.ReadValue("openssl", "cafile", 0);
 173                 certfile = Conf.ReadValue("openssl", "certfile", 0);
 174                 keyfile  = Conf.ReadValue("openssl", "keyfile", 0);
 175                 dhfile   = Conf.ReadValue("openssl", "dhfile", 0);
 176
 177                 // Set all the default values needed.
 178                 if (cafile.empty())
 179                         cafile = "conf/ca.pem";
 180
 181                 if (certfile.empty())
 182                         certfile = "conf/cert.pem";
 183
 184                 if (keyfile.empty())
 185                         keyfile = "conf/key.pem";
 186
 187                 if (dhfile.empty())
 188                         dhfile = "conf/dhparams.pem";
 189
 190                 /* Load our keys and certificates
 191                  * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 192                  */
 193                 if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
 194                 {
 195                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
 196                         ERR_print_errors_cb(error_callback, this);
 197                 }
 198
 199                 if (((!SSL_CTX_use_PrivateKey_file(ctx, keyfile.c_str(), SSL_FILETYPE_PEM))) || (!SSL_CTX_use_PrivateKey_file(clictx, keyfile.c_str(), SSL_FILETYPE_PEM)))
 200                 {
 201                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
 202                         ERR_print_errors_cb(error_callback, this);
 203                 }
 204
 205                 /* Load the CAs we trust*/
 206                 if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
 207                 {
 208                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
 209                         ERR_print_errors_cb(error_callback, this);
 210                 }
 211
 212                 FILE* dhpfile = fopen(dhfile.c_str(), "r");
 213                 DH* ret;
 214
 215                 if (dhpfile == NULL)
 216                 {
 217                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
 218                         throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
 219                 }
 220                 else
 221                 {
 222                         ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
 223                         if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
 224                         {
 225                                 ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
 226                                 ERR_print_errors_cb(error_callback, this);
 227                         }
 228                 }
 229
 230                 fclose(dhpfile);
 231         }
 232
 233         void On005Numeric(std::string &output)
 234         {
 235                 if (!sslports.empty())
 236                         output.append(" SSL=" + sslports);
 237         }
 238
 239         ~ModuleSSLOpenSSL()
 240         {
 241                 SSL_CTX_free(ctx);
 242                 SSL_CTX_free(clictx);
 243                 ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
 244                 delete[] sessions;
 245         }
 246
 247         void OnCleanup(int target_type, void* item)
 248         {
 249                 if (target_type == TYPE_USER)
 250                 {
 251                         LocalUser* user = IS_LOCAL((User*)item);
 252
 253                         if (user && user->eh.GetIOHook() == this)
 254                         {
 255                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 256                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 257                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 258                         }
 259                 }
 260         }
 261
 262         Version GetVersion()
 263         {
 264                 return Version("Provides SSL support for clients", VF_VENDOR);
 265         }
 266
 267
 268         void OnRequest(Request& request)
 269         {
 270                 Module* sslinfo = ServerInstance->Modules->Find("m_sslinfo.so");
 271                 if (sslinfo)
 272                         sslinfo->OnRequest(request);
 273         }
 274
 275
 276         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 277         {
 278                 int fd = user->GetFd();
 279
 280                 issl_session* session = &sessions[fd];
 281
 282                 session->fd = fd;
 283                 session->sess = SSL_new(ctx);
 284                 session->status = ISSL_NONE;
 285                 session->outbound = false;
 286
 287                 if (session->sess == NULL)
 288                         return;
 289
 290                 if (SSL_set_fd(session->sess, fd) == 0)
 291                 {
 292                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 293                         return;
 294                 }
 295
 296                 Handshake(user, session);
 297         }
 298
 299         void OnStreamSocketConnect(StreamSocket* user)
 300         {
 301                 int fd = user->GetFd();
 302                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 303                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 304                         return;
 305
 306                 issl_session* session = &sessions[fd];
 307
 308                 session->fd = fd;
 309                 session->sess = SSL_new(clictx);
 310                 session->status = ISSL_NONE;
 311                 session->outbound = true;
 312
 313                 if (session->sess == NULL)
 314                         return;
 315
 316                 if (SSL_set_fd(session->sess, fd) == 0)
 317                 {
 318                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 319                         return;
 320                 }
 321
 322                 Handshake(user, session);
 323         }
 324
 325         void OnStreamSocketClose(StreamSocket* user)
 326         {
 327                 int fd = user->GetFd();
 328                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 329                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 330                         return;
 331
 332                 CloseSession(&sessions[fd]);
 333         }
 334
 335         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 336         {
 337                 int fd = user->GetFd();
 338                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 339                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 340                         return -1;
 341
 342                 issl_session* session = &sessions[fd];
 343
 344                 if (!session->sess)
 345                 {
 346                         CloseSession(session);
 347                         return -1;
 348                 }
 349
 350                 if (session->status == ISSL_HANDSHAKING)
 351                 {
 352                         // The handshake isn't finished and it wants to read, try to finish it.
 353                         if (!Handshake(user, session))
 354                         {
 355                                 // Couldn't resume handshake.
 356                                 if (session->status == ISSL_NONE)
 357                                         return -1;
 358                                 return 0;
 359                         }
 360                 }
 361
 362                 // If we resumed the handshake then session->status will be ISSL_OPEN
 363
 364                 if (session->status == ISSL_OPEN)
 365                 {
 366                         char* buffer = ServerInstance->GetReadBuffer();
 367                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 368                         int ret = SSL_read(session->sess, buffer, bufsiz);
 369
 370                         if (ret > 0)
 371                         {
 372                                 recvq.append(buffer, ret);
 373                                 return 1;
 374                         }
 375                         else if (ret == 0)
 376                         {
 377                                 // Client closed connection.
 378                                 CloseSession(session);
 379                                 return -1;
 380                         }
 381                         else if (ret < 0)
 382                         {
 383                                 int err = SSL_get_error(session->sess, ret);
 384
 385                                 if (err == SSL_ERROR_WANT_READ)
 386                                 {
 387                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 388                                         return 0;
 389                                 }
 390                                 else if (err == SSL_ERROR_WANT_WRITE)
 391                                 {
 392                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 393                                         return 0;
 394                                 }
 395                                 else
 396                                 {
 397                                         CloseSession(session);
 398                                         return -1;
 399                                 }
 400                         }
 401                 }
 402
 403                 return 0;
 404         }
 405
 406         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 407         {
 408                 int fd = user->GetFd();
 409
 410                 issl_session* session = &sessions[fd];
 411
 412                 if (!session->sess)
 413                 {
 414                         CloseSession(session);
 415                         return -1;
 416                 }
 417
 418                 session->data_to_write = true;
 419
 420                 if (session->status == ISSL_HANDSHAKING)
 421                 {
 422                         if (!Handshake(user, session))
 423                         {
 424                                 // Couldn't resume handshake.
 425                                 if (session->status == ISSL_NONE)
 426                                         return -1;
 427                                 return 0;
 428                         }
 429                 }
 430
 431                 if (session->status == ISSL_OPEN)
 432                 {
 433                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 434                         if (ret == (int)buffer.length())
 435                         {
 436                                 session->data_to_write = false;
 437                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 438                                 return 1;
 439                         }
 440                         else if (ret > 0)
 441                         {
 442                                 buffer = buffer.substr(ret);
 443                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 444                                 return 0;
 445                         }
 446                         else if (ret == 0)
 447                         {
 448                                 CloseSession(session);
 449                                 return -1;
 450                         }
 451                         else if (ret < 0)
 452                         {
 453                                 int err = SSL_get_error(session->sess, ret);
 454
 455                                 if (err == SSL_ERROR_WANT_WRITE)
 456                                 {
 457                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 458                                         return 0;
 459                                 }
 460                                 else if (err == SSL_ERROR_WANT_READ)
 461                                 {
 462                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 463                                         return 0;
 464                                 }
 465                                 else
 466                                 {
 467                                         CloseSession(session);
 468                                         return -1;
 469                                 }
 470                         }
 471                 }
 472                 return 0;
 473         }
 474
 475         bool Handshake(EventHandler* user, issl_session* session)
 476         {
 477                 int ret;
 478
 479                 if (session->outbound)
 480                         ret = SSL_connect(session->sess);
 481                 else
 482                         ret = SSL_accept(session->sess);
 483
 484                 if (ret < 0)
 485                 {
 486                         int err = SSL_get_error(session->sess, ret);
 487
 488                         if (err == SSL_ERROR_WANT_READ)
 489                         {
 490                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 491                                 session->status = ISSL_HANDSHAKING;
 492                                 return true;
 493                         }
 494                         else if (err == SSL_ERROR_WANT_WRITE)
 495                         {
 496                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 497                                 session->status = ISSL_HANDSHAKING;
 498                                 return true;
 499                         }
 500                         else
 501                         {
 502                                 CloseSession(session);
 503                         }
 504
 505                         return false;
 506                 }
 507                 else if (ret > 0)
 508                 {
 509                         // Handshake complete.
 510                         VerifyCertificate(session, user);
 511
 512                         session->status = ISSL_OPEN;
 513
 514                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 515
 516                         return true;
 517                 }
 518                 else if (ret == 0)
 519                 {
 520                         CloseSession(session);
 521                         return true;
 522                 }
 523
 524                 return true;
 525         }
 526
 527         void CloseSession(issl_session* session)
 528         {
 529                 if (session->sess)
 530                 {
 531                         SSL_shutdown(session->sess);
 532                         SSL_free(session->sess);
 533                 }
 534
 535                 session->sess = NULL;
 536                 session->status = ISSL_NONE;
 537                 errno = EIO;
 538         }
 539
 540         void VerifyCertificate(issl_session* session, Extensible* user)
 541         {
 542                 if (!session->sess || !user)
 543                         return;
 544
 545                 Module* sslinfo = ServerInstance->Modules->Find("m_sslinfo.so");
 546                 if (!sslinfo)
 547                         return;
 548
 549                 X509* cert;
 550                 ssl_cert* certinfo = new ssl_cert;
 551                 unsigned int n;
 552                 unsigned char md[EVP_MAX_MD_SIZE];
 553                 const EVP_MD *digest = EVP_md5();
 554
 555                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 556
 557                 if (!cert)
 558                 {
 559                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 560                         SSLCertSubmission(user, this, sslinfo, certinfo);
 561                         return;
 562                 }
 563
 564                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 565
 566                 if (SelfSigned)
 567                 {
 568                         certinfo->unknownsigner = false;
 569                         certinfo->trusted = true;
 570                 }
 571                 else
 572                 {
 573                         certinfo->unknownsigner = true;
 574                         certinfo->trusted = false;
 575                 }
 576
 577                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 578                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 579
 580                 if (!X509_digest(cert, digest, md, &n))
 581                 {
 582                         certinfo->error = "Out of memory generating fingerprint";
 583                 }
 584                 else
 585                 {
 586                         certinfo->fingerprint = irc::hex(md, n);
 587                 }
 588
 589                 if ((ASN1_UTCTIME_cmp_time_t(X509_get_notAfter(cert), ServerInstance->Time()) == -1) || (ASN1_UTCTIME_cmp_time_t(X509_get_notBefore(cert), ServerInstance->Time()) == 0))
 590                 {
 591                         certinfo->error = "Not activated, or expired certificate";
 592                 }
 593
 594                 X509_free(cert);
 595                 SSLCertSubmission(user, this, sslinfo, certinfo);
 596         }
 597 };
 598
 599 static int error_callback(const char *str, size_t len, void *u)
 600 {
 601         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 602
 603         //
 604         // XXX: Remove this line, it causes valgrind warnings...
 605         //
 606         // MD_update(&m, buf, j);
 607         //
 608         //
 609         // ... ONLY JOKING! :-)
 610         //
 611
 612         return 0;
 613 }
 614
 615 MODULE_INIT(ModuleSSLOpenSSL)