src/modules/extra/m_ssl_openssl.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 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 /* $NoPedantic */
  33 /* $CopyInstall: conf/key.pem $(CONPATH) -m 0400 -o $(INSTUID) */
  34 /* $CopyInstall: conf/cert.pem $(CONPATH) -m 0444 */
  35
  36
  37 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
  38
  39 static bool SelfSigned = false;
  40
  41 char* get_error()
  42 {
  43         return ERR_error_string(ERR_get_error(), NULL);
  44 }
  45
  46 static int error_callback(const char *str, size_t len, void *u);
  47
  48 /** Represents an SSL user's extra data
  49  */
  50 class issl_session
  51 {
  52 public:
  53         SSL* sess;
  54         issl_status status;
  55         reference<ssl_cert> cert;
  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         ServiceProvider iohook;
 100  public:
 101
 102         ModuleSSLOpenSSL() : iohook(this, "ssl/openssl", SERVICE_IOHOOK)
 103         {
 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, I_OnUserConnect };
 129                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 130                 ServerInstance->Modules->AddService(iohook);
 131         }
 132
 133         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 134         {
 135                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "openssl")
 136                 {
 137                         /* Hook the user with our module */
 138                         user->AddIOHook(this);
 139                 }
 140         }
 141
 142         void OnRehash(User* user)
 143         {
 144                 ConfigReader Conf;
 145
 146                 sslports.clear();
 147
 148                 for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 149                 {
 150                         ListenSocket* port = ServerInstance->ports[i];
 151                         if (port->bind_tag->getString("ssl") != "openssl")
 152                                 continue;
 153
 154                         std::string portid = port->bind_desc;
 155                         ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 156                         if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 157                                 sslports.append(portid).append(";");
 158                 }
 159
 160                 if (!sslports.empty())
 161                         sslports.erase(sslports.end() - 1);
 162         }
 163
 164         void OnModuleRehash(User* user, const std::string &param)
 165         {
 166                 if (param != "ssl")
 167                         return;
 168
 169                 OnRehash(user);
 170
 171                 ConfigReader Conf;
 172
 173                 cafile   = Conf.ReadValue("openssl", "cafile", 0);
 174                 certfile = Conf.ReadValue("openssl", "certfile", 0);
 175                 keyfile  = Conf.ReadValue("openssl", "keyfile", 0);
 176                 dhfile   = Conf.ReadValue("openssl", "dhfile", 0);
 177
 178                 // Set all the default values needed.
 179                 if (cafile.empty())
 180                         cafile = "conf/ca.pem";
 181
 182                 if (certfile.empty())
 183                         certfile = "conf/cert.pem";
 184
 185                 if (keyfile.empty())
 186                         keyfile = "conf/key.pem";
 187
 188                 if (dhfile.empty())
 189                         dhfile = "conf/dhparams.pem";
 190
 191                 /* Load our keys and certificates
 192                  * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 193                  */
 194                 if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
 195                 {
 196                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
 197                         ERR_print_errors_cb(error_callback, this);
 198                 }
 199
 200                 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)))
 201                 {
 202                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
 203                         ERR_print_errors_cb(error_callback, this);
 204                 }
 205
 206                 /* Load the CAs we trust*/
 207                 if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
 208                 {
 209                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
 210                         ERR_print_errors_cb(error_callback, this);
 211                 }
 212
 213                 FILE* dhpfile = fopen(dhfile.c_str(), "r");
 214                 DH* ret;
 215
 216                 if (dhpfile == NULL)
 217                 {
 218                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
 219                         throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
 220                 }
 221                 else
 222                 {
 223                         ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
 224                         if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
 225                         {
 226                                 ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
 227                                 ERR_print_errors_cb(error_callback, this);
 228                         }
 229                 }
 230
 231                 fclose(dhpfile);
 232         }
 233
 234         void On005Numeric(std::string &output)
 235         {
 236                 if (!sslports.empty())
 237                         output.append(" SSL=" + sslports);
 238         }
 239
 240         ~ModuleSSLOpenSSL()
 241         {
 242                 SSL_CTX_free(ctx);
 243                 SSL_CTX_free(clictx);
 244                 delete[] sessions;
 245         }
 246
 247         void OnUserConnect(LocalUser* user)
 248         {
 249                 if (user->eh.GetIOHook() == this)
 250                 {
 251                         if (sessions[user->GetFd()].sess)
 252                         {
 253                                 SSLCertSubmission(user, this, ServerInstance->Modules->Find("m_sslinfo.so"), sessions[user->GetFd()].cert);
 254                         }
 255                 }
 256         }
 257
 258         void OnCleanup(int target_type, void* item)
 259         {
 260                 if (target_type == TYPE_USER)
 261                 {
 262                         LocalUser* user = IS_LOCAL((User*)item);
 263
 264                         if (user && user->eh.GetIOHook() == this)
 265                         {
 266                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 267                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 268                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 269                         }
 270                 }
 271         }
 272
 273         Version GetVersion()
 274         {
 275                 return Version("Provides SSL support for clients", VF_VENDOR);
 276         }
 277
 278         void OnRequest(Request& request)
 279         {
 280                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 281                 {
 282                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 283                         int fd = req.sock->GetFd();
 284                         issl_session* session = &sessions[fd];
 285
 286                         req.cert = session->cert;
 287                 }
 288         }
 289
 290         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 291         {
 292                 int fd = user->GetFd();
 293
 294                 issl_session* session = &sessions[fd];
 295
 296                 session->fd = fd;
 297                 session->sess = SSL_new(ctx);
 298                 session->status = ISSL_NONE;
 299                 session->outbound = false;
 300
 301                 if (session->sess == NULL)
 302                         return;
 303
 304                 if (SSL_set_fd(session->sess, fd) == 0)
 305                 {
 306                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 307                         return;
 308                 }
 309
 310                 Handshake(user, session);
 311         }
 312
 313         void OnStreamSocketConnect(StreamSocket* user)
 314         {
 315                 int fd = user->GetFd();
 316                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 317                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 318                         return;
 319
 320                 issl_session* session = &sessions[fd];
 321
 322                 session->fd = fd;
 323                 session->sess = SSL_new(clictx);
 324                 session->status = ISSL_NONE;
 325                 session->outbound = true;
 326
 327                 if (session->sess == NULL)
 328                         return;
 329
 330                 if (SSL_set_fd(session->sess, fd) == 0)
 331                 {
 332                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 333                         return;
 334                 }
 335
 336                 Handshake(user, session);
 337         }
 338
 339         void OnStreamSocketClose(StreamSocket* user)
 340         {
 341                 int fd = user->GetFd();
 342                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 343                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 344                         return;
 345
 346                 CloseSession(&sessions[fd]);
 347         }
 348
 349         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 350         {
 351                 int fd = user->GetFd();
 352                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 353                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 354                         return -1;
 355
 356                 issl_session* session = &sessions[fd];
 357
 358                 if (!session->sess)
 359                 {
 360                         CloseSession(session);
 361                         return -1;
 362                 }
 363
 364                 if (session->status == ISSL_HANDSHAKING)
 365                 {
 366                         // The handshake isn't finished and it wants to read, try to finish it.
 367                         if (!Handshake(user, session))
 368                         {
 369                                 // Couldn't resume handshake.
 370                                 if (session->status == ISSL_NONE)
 371                                         return -1;
 372                                 return 0;
 373                         }
 374                 }
 375
 376                 // If we resumed the handshake then session->status will be ISSL_OPEN
 377
 378                 if (session->status == ISSL_OPEN)
 379                 {
 380                         char* buffer = ServerInstance->GetReadBuffer();
 381                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 382                         int ret = SSL_read(session->sess, buffer, bufsiz);
 383
 384                         if (ret > 0)
 385                         {
 386                                 recvq.append(buffer, ret);
 387                                 return 1;
 388                         }
 389                         else if (ret == 0)
 390                         {
 391                                 // Client closed connection.
 392                                 CloseSession(session);
 393                                 return -1;
 394                         }
 395                         else if (ret < 0)
 396                         {
 397                                 int err = SSL_get_error(session->sess, ret);
 398
 399                                 if (err == SSL_ERROR_WANT_READ)
 400                                 {
 401                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 402                                         return 0;
 403                                 }
 404                                 else if (err == SSL_ERROR_WANT_WRITE)
 405                                 {
 406                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 407                                         return 0;
 408                                 }
 409                                 else
 410                                 {
 411                                         CloseSession(session);
 412                                         return -1;
 413                                 }
 414                         }
 415                 }
 416
 417                 return 0;
 418         }
 419
 420         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 421         {
 422                 int fd = user->GetFd();
 423
 424                 issl_session* session = &sessions[fd];
 425
 426                 if (!session->sess)
 427                 {
 428                         CloseSession(session);
 429                         return -1;
 430                 }
 431
 432                 session->data_to_write = true;
 433
 434                 if (session->status == ISSL_HANDSHAKING)
 435                 {
 436                         if (!Handshake(user, session))
 437                         {
 438                                 // Couldn't resume handshake.
 439                                 if (session->status == ISSL_NONE)
 440                                         return -1;
 441                                 return 0;
 442                         }
 443                 }
 444
 445                 if (session->status == ISSL_OPEN)
 446                 {
 447                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 448                         if (ret == (int)buffer.length())
 449                         {
 450                                 session->data_to_write = false;
 451                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 452                                 return 1;
 453                         }
 454                         else if (ret > 0)
 455                         {
 456                                 buffer = buffer.substr(ret);
 457                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 458                                 return 0;
 459                         }
 460                         else if (ret == 0)
 461                         {
 462                                 CloseSession(session);
 463                                 return -1;
 464                         }
 465                         else if (ret < 0)
 466                         {
 467                                 int err = SSL_get_error(session->sess, ret);
 468
 469                                 if (err == SSL_ERROR_WANT_WRITE)
 470                                 {
 471                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 472                                         return 0;
 473                                 }
 474                                 else if (err == SSL_ERROR_WANT_READ)
 475                                 {
 476                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 477                                         return 0;
 478                                 }
 479                                 else
 480                                 {
 481                                         CloseSession(session);
 482                                         return -1;
 483                                 }
 484                         }
 485                 }
 486                 return 0;
 487         }
 488
 489         bool Handshake(StreamSocket* user, issl_session* session)
 490         {
 491                 int ret;
 492
 493                 if (session->outbound)
 494                         ret = SSL_connect(session->sess);
 495                 else
 496                         ret = SSL_accept(session->sess);
 497
 498                 if (ret < 0)
 499                 {
 500                         int err = SSL_get_error(session->sess, ret);
 501
 502                         if (err == SSL_ERROR_WANT_READ)
 503                         {
 504                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 505                                 session->status = ISSL_HANDSHAKING;
 506                                 return true;
 507                         }
 508                         else if (err == SSL_ERROR_WANT_WRITE)
 509                         {
 510                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 511                                 session->status = ISSL_HANDSHAKING;
 512                                 return true;
 513                         }
 514                         else
 515                         {
 516                                 CloseSession(session);
 517                         }
 518
 519                         return false;
 520                 }
 521                 else if (ret > 0)
 522                 {
 523                         // Handshake complete.
 524                         VerifyCertificate(session, user);
 525
 526                         session->status = ISSL_OPEN;
 527
 528                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 529
 530                         return true;
 531                 }
 532                 else if (ret == 0)
 533                 {
 534                         CloseSession(session);
 535                         return true;
 536                 }
 537
 538                 return true;
 539         }
 540
 541         void CloseSession(issl_session* session)
 542         {
 543                 if (session->sess)
 544                 {
 545                         SSL_shutdown(session->sess);
 546                         SSL_free(session->sess);
 547                 }
 548
 549                 session->sess = NULL;
 550                 session->status = ISSL_NONE;
 551                 errno = EIO;
 552         }
 553
 554         void VerifyCertificate(issl_session* session, StreamSocket* user)
 555         {
 556                 if (!session->sess || !user || session->cert)
 557                         return;
 558
 559                 X509* cert;
 560                 ssl_cert* certinfo = new ssl_cert;
 561                 session->cert = certinfo;
 562                 unsigned int n;
 563                 unsigned char md[EVP_MAX_MD_SIZE];
 564                 const EVP_MD *digest = EVP_md5();
 565
 566                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 567
 568                 if (!cert)
 569                 {
 570                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 571                         return;
 572                 }
 573
 574                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 575
 576                 if (SelfSigned)
 577                 {
 578                         certinfo->unknownsigner = false;
 579                         certinfo->trusted = true;
 580                 }
 581                 else
 582                 {
 583                         certinfo->unknownsigner = true;
 584                         certinfo->trusted = false;
 585                 }
 586
 587                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 588                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 589
 590                 if (!X509_digest(cert, digest, md, &n))
 591                 {
 592                         certinfo->error = "Out of memory generating fingerprint";
 593                 }
 594                 else
 595                 {
 596                         certinfo->fingerprint = irc::hex(md, n);
 597                 }
 598
 599                 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))
 600                 {
 601                         certinfo->error = "Not activated, or expired certificate";
 602                 }
 603
 604                 X509_free(cert);
 605         }
 606 };
 607
 608 static int error_callback(const char *str, size_t len, void *u)
 609 {
 610         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 611
 612         //
 613         // XXX: Remove this line, it causes valgrind warnings...
 614         //
 615         // MD_update(&m, buf, j);
 616         //
 617         //
 618         // ... ONLY JOKING! :-)
 619         //
 620
 621         return 0;
 622 }
 623
 624 MODULE_INIT(ModuleSSLOpenSSL)