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->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                                 user->DelIOHook();
 259                         }
 260                 }
 261         }
 262
 263         Version GetVersion()
 264         {
 265                 return Version("Provides SSL support for clients", VF_VENDOR);
 266         }
 267
 268
 269         void OnRequest(Request& request)
 270         {
 271                 Module* sslinfo = ServerInstance->Modules->Find("m_sslinfo.so");
 272                 if (sslinfo)
 273                         sslinfo->OnRequest(request);
 274         }
 275
 276
 277         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 278         {
 279                 int fd = user->GetFd();
 280
 281                 issl_session* session = &sessions[fd];
 282
 283                 session->fd = fd;
 284                 session->sess = SSL_new(ctx);
 285                 session->status = ISSL_NONE;
 286                 session->outbound = false;
 287
 288                 if (session->sess == NULL)
 289                         return;
 290
 291                 if (SSL_set_fd(session->sess, fd) == 0)
 292                 {
 293                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 294                         return;
 295                 }
 296
 297                 Handshake(user, session);
 298         }
 299
 300         void OnStreamSocketConnect(StreamSocket* user)
 301         {
 302                 int fd = user->GetFd();
 303                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 304                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 305                         return;
 306
 307                 issl_session* session = &sessions[fd];
 308
 309                 session->fd = fd;
 310                 session->sess = SSL_new(clictx);
 311                 session->status = ISSL_NONE;
 312                 session->outbound = true;
 313
 314                 if (session->sess == NULL)
 315                         return;
 316
 317                 if (SSL_set_fd(session->sess, fd) == 0)
 318                 {
 319                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 320                         return;
 321                 }
 322
 323                 Handshake(user, session);
 324         }
 325
 326         void OnStreamSocketClose(StreamSocket* user)
 327         {
 328                 int fd = user->GetFd();
 329                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 330                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 331                         return;
 332
 333                 CloseSession(&sessions[fd]);
 334         }
 335
 336         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 337         {
 338                 int fd = user->GetFd();
 339                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 340                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 341                         return -1;
 342
 343                 issl_session* session = &sessions[fd];
 344
 345                 if (!session->sess)
 346                 {
 347                         CloseSession(session);
 348                         return -1;
 349                 }
 350
 351                 if (session->status == ISSL_HANDSHAKING)
 352                 {
 353                         // The handshake isn't finished and it wants to read, try to finish it.
 354                         if (!Handshake(user, session))
 355                         {
 356                                 // Couldn't resume handshake.
 357                                 if (session->status == ISSL_NONE)
 358                                         return -1;
 359                                 return 0;
 360                         }
 361                 }
 362
 363                 // If we resumed the handshake then session->status will be ISSL_OPEN
 364
 365                 if (session->status == ISSL_OPEN)
 366                 {
 367                         char* buffer = ServerInstance->GetReadBuffer();
 368                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 369                         int ret = SSL_read(session->sess, buffer, bufsiz);
 370
 371                         if (ret > 0)
 372                         {
 373                                 recvq.append(buffer, ret);
 374                                 return 1;
 375                         }
 376                         else if (ret == 0)
 377                         {
 378                                 // Client closed connection.
 379                                 CloseSession(session);
 380                                 return -1;
 381                         }
 382                         else if (ret < 0)
 383                         {
 384                                 int err = SSL_get_error(session->sess, ret);
 385
 386                                 if (err == SSL_ERROR_WANT_READ)
 387                                 {
 388                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 389                                         return 0;
 390                                 }
 391                                 else if (err == SSL_ERROR_WANT_WRITE)
 392                                 {
 393                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 394                                         return 0;
 395                                 }
 396                                 else
 397                                 {
 398                                         CloseSession(session);
 399                                         return -1;
 400                                 }
 401                         }
 402                 }
 403
 404                 return 0;
 405         }
 406
 407         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 408         {
 409                 int fd = user->GetFd();
 410
 411                 issl_session* session = &sessions[fd];
 412
 413                 if (!session->sess)
 414                 {
 415                         CloseSession(session);
 416                         return -1;
 417                 }
 418
 419                 session->data_to_write = true;
 420
 421                 if (session->status == ISSL_HANDSHAKING)
 422                 {
 423                         if (!Handshake(user, session))
 424                         {
 425                                 // Couldn't resume handshake.
 426                                 if (session->status == ISSL_NONE)
 427                                         return -1;
 428                                 return 0;
 429                         }
 430                 }
 431
 432                 if (session->status == ISSL_OPEN)
 433                 {
 434                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 435                         if (ret == (int)buffer.length())
 436                         {
 437                                 session->data_to_write = false;
 438                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 439                                 return 1;
 440                         }
 441                         else if (ret > 0)
 442                         {
 443                                 buffer = buffer.substr(ret);
 444                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 445                                 return 0;
 446                         }
 447                         else if (ret == 0)
 448                         {
 449                                 CloseSession(session);
 450                                 return -1;
 451                         }
 452                         else if (ret < 0)
 453                         {
 454                                 int err = SSL_get_error(session->sess, ret);
 455
 456                                 if (err == SSL_ERROR_WANT_WRITE)
 457                                 {
 458                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 459                                         return 0;
 460                                 }
 461                                 else if (err == SSL_ERROR_WANT_READ)
 462                                 {
 463                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 464                                         return 0;
 465                                 }
 466                                 else
 467                                 {
 468                                         CloseSession(session);
 469                                         return -1;
 470                                 }
 471                         }
 472                 }
 473                 return 0;
 474         }
 475
 476         bool Handshake(EventHandler* user, issl_session* session)
 477         {
 478                 int ret;
 479
 480                 if (session->outbound)
 481                         ret = SSL_connect(session->sess);
 482                 else
 483                         ret = SSL_accept(session->sess);
 484
 485                 if (ret < 0)
 486                 {
 487                         int err = SSL_get_error(session->sess, ret);
 488
 489                         if (err == SSL_ERROR_WANT_READ)
 490                         {
 491                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 492                                 session->status = ISSL_HANDSHAKING;
 493                                 return true;
 494                         }
 495                         else if (err == SSL_ERROR_WANT_WRITE)
 496                         {
 497                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 498                                 session->status = ISSL_HANDSHAKING;
 499                                 return true;
 500                         }
 501                         else
 502                         {
 503                                 CloseSession(session);
 504                         }
 505
 506                         return false;
 507                 }
 508                 else if (ret > 0)
 509                 {
 510                         // Handshake complete.
 511                         VerifyCertificate(session, user);
 512
 513                         session->status = ISSL_OPEN;
 514
 515                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 516
 517                         return true;
 518                 }
 519                 else if (ret == 0)
 520                 {
 521                         CloseSession(session);
 522                         return true;
 523                 }
 524
 525                 return true;
 526         }
 527
 528         void CloseSession(issl_session* session)
 529         {
 530                 if (session->sess)
 531                 {
 532                         SSL_shutdown(session->sess);
 533                         SSL_free(session->sess);
 534                 }
 535
 536                 session->sess = NULL;
 537                 session->status = ISSL_NONE;
 538                 errno = EIO;
 539         }
 540
 541         void VerifyCertificate(issl_session* session, Extensible* user)
 542         {
 543                 if (!session->sess || !user)
 544                         return;
 545
 546                 Module* sslinfo = ServerInstance->Modules->Find("m_sslinfo.so");
 547                 if (!sslinfo)
 548                         return;
 549
 550                 X509* cert;
 551                 ssl_cert* certinfo = new ssl_cert;
 552                 unsigned int n;
 553                 unsigned char md[EVP_MAX_MD_SIZE];
 554                 const EVP_MD *digest = EVP_md5();
 555
 556                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 557
 558                 if (!cert)
 559                 {
 560                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 561                         SSLCertSubmission(user, this, sslinfo, certinfo);
 562                         return;
 563                 }
 564
 565                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 566
 567                 if (SelfSigned)
 568                 {
 569                         certinfo->unknownsigner = false;
 570                         certinfo->trusted = true;
 571                 }
 572                 else
 573                 {
 574                         certinfo->unknownsigner = true;
 575                         certinfo->trusted = false;
 576                 }
 577
 578                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 579                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 580
 581                 if (!X509_digest(cert, digest, md, &n))
 582                 {
 583                         certinfo->error = "Out of memory generating fingerprint";
 584                 }
 585                 else
 586                 {
 587                         certinfo->fingerprint = irc::hex(md, n);
 588                 }
 589
 590                 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))
 591                 {
 592                         certinfo->error = "Not activated, or expired certificate";
 593                 }
 594
 595                 X509_free(cert);
 596                 SSLCertSubmission(user, this, sslinfo, certinfo);
 597         }
 598 };
 599
 600 static int error_callback(const char *str, size_t len, void *u)
 601 {
 602         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 603
 604         //
 605         // XXX: Remove this line, it causes valgrind warnings...
 606         //
 607         // MD_update(&m, buf, j);
 608         //
 609         //
 610         // ... ONLY JOKING! :-)
 611         //
 612
 613         return 0;
 614 }
 615
 616 MODULE_INIT(ModuleSSLOpenSSL)