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
  34
  35 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
  36
  37 static bool SelfSigned = false;
  38
  39 char* get_error()
  40 {
  41         return ERR_error_string(ERR_get_error(), NULL);
  42 }
  43
  44 static int error_callback(const char *str, size_t len, void *u);
  45
  46 /** Represents an SSL user's extra data
  47  */
  48 class issl_session
  49 {
  50 public:
  51         SSL* sess;
  52         issl_status status;
  53         reference<ssl_cert> cert;
  54
  55         int fd;
  56         bool outbound;
  57         bool data_to_write;
  58
  59         issl_session()
  60         {
  61                 outbound = false;
  62                 data_to_write = false;
  63         }
  64 };
  65
  66 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
  67 {
  68         /* XXX: This will allow self signed certificates.
  69          * In the future if we want an option to not allow this,
  70          * we can just return preverify_ok here, and openssl
  71          * will boot off self-signed and invalid peer certs.
  72          */
  73         int ve = X509_STORE_CTX_get_error(ctx);
  74
  75         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
  76
  77         return 1;
  78 }
  79
  80 class ModuleSSLOpenSSL : public Module
  81 {
  82         int inbufsize;
  83         issl_session* sessions;
  84
  85         SSL_CTX* ctx;
  86         SSL_CTX* clictx;
  87
  88         char cipher[MAXBUF];
  89
  90         std::string sslports;
  91         bool use_sha;
  92
  93         ServiceProvider iohook;
  94  public:
  95
  96         ModuleSSLOpenSSL() : iohook(this, "ssl/openssl", SERVICE_IOHOOK)
  97         {
  98                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
  99
 100                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 101                 inbufsize = ServerInstance->Config->NetBufferSize;
 102
 103                 /* Global SSL library initialization*/
 104                 SSL_library_init();
 105                 SSL_load_error_strings();
 106
 107                 /* Build our SSL contexts:
 108                  * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
 109                  */
 110                 ctx = SSL_CTX_new( SSLv23_server_method() );
 111                 clictx = SSL_CTX_new( SSLv23_client_method() );
 112
 113                 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 114                 SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 115
 116                 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 117                 SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 118         }
 119
 120         void init()
 121         {
 122                 // Needs the flag as it ignores a plain /rehash
 123                 OnModuleRehash(NULL,"ssl");
 124                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnHookIO, I_OnUserConnect };
 125                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 126                 ServerInstance->Modules->AddService(iohook);
 127         }
 128
 129         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 130         {
 131                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "openssl")
 132                 {
 133                         /* Hook the user with our module */
 134                         user->AddIOHook(this);
 135                 }
 136         }
 137
 138         void OnRehash(User* user)
 139         {
 140                 ConfigReader Conf;
 141
 142                 sslports.clear();
 143
 144                 for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 145                 {
 146                         ListenSocket* port = ServerInstance->ports[i];
 147                         if (port->bind_tag->getString("ssl") != "openssl")
 148                                 continue;
 149
 150                         std::string portid = port->bind_desc;
 151                         ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 152                         if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 153                                 sslports.append(portid).append(";");
 154                 }
 155
 156                 if (!sslports.empty())
 157                         sslports.erase(sslports.end() - 1);
 158         }
 159
 160         void OnModuleRehash(User* user, const std::string &param)
 161         {
 162                 if (param != "ssl")
 163                         return;
 164
 165                 std::string keyfile;
 166                 std::string certfile;
 167                 std::string cafile;
 168                 std::string dhfile;
 169                 OnRehash(user);
 170
 171                 ConfigTag* conf = ServerInstance->Config->ConfValue("openssl");
 172
 173                 cafile   = conf->getString("cafile", "conf/ca.pem");
 174                 certfile = conf->getString("certfile", "conf/cert.pem");
 175                 keyfile  = conf->getString("keyfile", "conf/key.pem");
 176                 dhfile   = conf->getString("dhfile", "conf/dhparams.pem");
 177                 std::string hash = conf->getString("hash", "md5");
 178                 if (hash != "sha1" && hash != "md5")
 179                         throw ModuleException("Unknown hash type " + hash);
 180                 use_sha = (hash == "sha1");
 181
 182
 183                 /* Load our keys and certificates
 184                  * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 185                  */
 186                 if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
 187                 {
 188                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
 189                         ERR_print_errors_cb(error_callback, this);
 190                 }
 191
 192                 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)))
 193                 {
 194                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
 195                         ERR_print_errors_cb(error_callback, this);
 196                 }
 197
 198                 /* Load the CAs we trust*/
 199                 if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
 200                 {
 201                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
 202                         ERR_print_errors_cb(error_callback, this);
 203                 }
 204
 205                 FILE* dhpfile = fopen(dhfile.c_str(), "r");
 206                 DH* ret;
 207
 208                 if (dhpfile == NULL)
 209                 {
 210                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
 211                         throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
 212                 }
 213                 else
 214                 {
 215                         ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
 216                         if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
 217                         {
 218                                 ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
 219                                 ERR_print_errors_cb(error_callback, this);
 220                         }
 221                 }
 222
 223                 fclose(dhpfile);
 224         }
 225
 226         void On005Numeric(std::string &output)
 227         {
 228                 if (!sslports.empty())
 229                         output.append(" SSL=" + sslports);
 230         }
 231
 232         ~ModuleSSLOpenSSL()
 233         {
 234                 SSL_CTX_free(ctx);
 235                 SSL_CTX_free(clictx);
 236                 delete[] sessions;
 237         }
 238
 239         void OnUserConnect(LocalUser* user)
 240         {
 241                 if (user->eh.GetIOHook() == this)
 242                 {
 243                         if (sessions[user->eh.GetFd()].sess)
 244                         {
 245                                 SSLCertSubmission(user, this, ServerInstance->Modules->Find("m_sslinfo.so"), sessions[user->eh.GetFd()].cert);
 246
 247                                 if (!sessions[user->eh.GetFd()].cert->fingerprint.empty())
 248                                         user->WriteServ("NOTICE %s :*** You are connected using SSL fingerprint %s",
 249                                                 user->nick.c_str(), sessions[user->eh.GetFd()].cert->fingerprint.c_str());
 250                         }
 251                 }
 252         }
 253
 254         void OnCleanup(int target_type, void* item)
 255         {
 256                 if (target_type == TYPE_USER)
 257                 {
 258                         LocalUser* user = IS_LOCAL((User*)item);
 259
 260                         if (user && user->eh.GetIOHook() == this)
 261                         {
 262                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 263                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 264                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 265                         }
 266                 }
 267         }
 268
 269         Version GetVersion()
 270         {
 271                 return Version("Provides SSL support for clients", VF_VENDOR);
 272         }
 273
 274         void OnRequest(Request& request)
 275         {
 276                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 277                 {
 278                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 279                         int fd = req.sock->GetFd();
 280                         issl_session* session = &sessions[fd];
 281
 282                         req.cert = session->cert;
 283                 }
 284         }
 285
 286         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 287         {
 288                 int fd = user->GetFd();
 289
 290                 issl_session* session = &sessions[fd];
 291
 292                 session->fd = fd;
 293                 session->sess = SSL_new(ctx);
 294                 session->status = ISSL_NONE;
 295                 session->outbound = false;
 296
 297                 if (session->sess == NULL)
 298                         return;
 299
 300                 if (SSL_set_fd(session->sess, fd) == 0)
 301                 {
 302                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 303                         return;
 304                 }
 305
 306                 Handshake(user, session);
 307         }
 308
 309         void OnStreamSocketConnect(StreamSocket* user)
 310         {
 311                 int fd = user->GetFd();
 312                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 313                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 314                         return;
 315
 316                 issl_session* session = &sessions[fd];
 317
 318                 session->fd = fd;
 319                 session->sess = SSL_new(clictx);
 320                 session->status = ISSL_NONE;
 321                 session->outbound = true;
 322
 323                 if (session->sess == NULL)
 324                         return;
 325
 326                 if (SSL_set_fd(session->sess, fd) == 0)
 327                 {
 328                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 329                         return;
 330                 }
 331
 332                 Handshake(user, session);
 333         }
 334
 335         void OnStreamSocketClose(StreamSocket* user)
 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;
 341
 342                 CloseSession(&sessions[fd]);
 343         }
 344
 345         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 346         {
 347                 int fd = user->GetFd();
 348                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 349                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 350                         return -1;
 351
 352                 issl_session* session = &sessions[fd];
 353
 354                 if (!session->sess)
 355                 {
 356                         CloseSession(session);
 357                         return -1;
 358                 }
 359
 360                 if (session->status == ISSL_HANDSHAKING)
 361                 {
 362                         // The handshake isn't finished and it wants to read, try to finish it.
 363                         if (!Handshake(user, session))
 364                         {
 365                                 // Couldn't resume handshake.
 366                                 if (session->status == ISSL_NONE)
 367                                         return -1;
 368                                 return 0;
 369                         }
 370                 }
 371
 372                 // If we resumed the handshake then session->status will be ISSL_OPEN
 373
 374                 if (session->status == ISSL_OPEN)
 375                 {
 376                         char* buffer = ServerInstance->GetReadBuffer();
 377                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 378                         int ret = SSL_read(session->sess, buffer, bufsiz);
 379
 380                         if (ret > 0)
 381                         {
 382                                 recvq.append(buffer, ret);
 383                                 return 1;
 384                         }
 385                         else if (ret == 0)
 386                         {
 387                                 // Client closed connection.
 388                                 CloseSession(session);
 389                                 return -1;
 390                         }
 391                         else if (ret < 0)
 392                         {
 393                                 int err = SSL_get_error(session->sess, ret);
 394
 395                                 if (err == SSL_ERROR_WANT_READ)
 396                                 {
 397                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 398                                         return 0;
 399                                 }
 400                                 else if (err == SSL_ERROR_WANT_WRITE)
 401                                 {
 402                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 403                                         return 0;
 404                                 }
 405                                 else
 406                                 {
 407                                         CloseSession(session);
 408                                         return -1;
 409                                 }
 410                         }
 411                 }
 412
 413                 return 0;
 414         }
 415
 416         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 417         {
 418                 int fd = user->GetFd();
 419
 420                 issl_session* session = &sessions[fd];
 421
 422                 if (!session->sess)
 423                 {
 424                         CloseSession(session);
 425                         return -1;
 426                 }
 427
 428                 session->data_to_write = true;
 429
 430                 if (session->status == ISSL_HANDSHAKING)
 431                 {
 432                         if (!Handshake(user, session))
 433                         {
 434                                 // Couldn't resume handshake.
 435                                 if (session->status == ISSL_NONE)
 436                                         return -1;
 437                                 return 0;
 438                         }
 439                 }
 440
 441                 if (session->status == ISSL_OPEN)
 442                 {
 443                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 444                         if (ret == (int)buffer.length())
 445                         {
 446                                 session->data_to_write = false;
 447                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 448                                 return 1;
 449                         }
 450                         else if (ret > 0)
 451                         {
 452                                 buffer = buffer.substr(ret);
 453                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 454                                 return 0;
 455                         }
 456                         else if (ret == 0)
 457                         {
 458                                 CloseSession(session);
 459                                 return -1;
 460                         }
 461                         else if (ret < 0)
 462                         {
 463                                 int err = SSL_get_error(session->sess, ret);
 464
 465                                 if (err == SSL_ERROR_WANT_WRITE)
 466                                 {
 467                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 468                                         return 0;
 469                                 }
 470                                 else if (err == SSL_ERROR_WANT_READ)
 471                                 {
 472                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 473                                         return 0;
 474                                 }
 475                                 else
 476                                 {
 477                                         CloseSession(session);
 478                                         return -1;
 479                                 }
 480                         }
 481                 }
 482                 return 0;
 483         }
 484
 485         bool Handshake(StreamSocket* user, issl_session* session)
 486         {
 487                 int ret;
 488
 489                 if (session->outbound)
 490                         ret = SSL_connect(session->sess);
 491                 else
 492                         ret = SSL_accept(session->sess);
 493
 494                 if (ret < 0)
 495                 {
 496                         int err = SSL_get_error(session->sess, ret);
 497
 498                         if (err == SSL_ERROR_WANT_READ)
 499                         {
 500                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 501                                 session->status = ISSL_HANDSHAKING;
 502                                 return true;
 503                         }
 504                         else if (err == SSL_ERROR_WANT_WRITE)
 505                         {
 506                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 507                                 session->status = ISSL_HANDSHAKING;
 508                                 return true;
 509                         }
 510                         else
 511                         {
 512                                 CloseSession(session);
 513                         }
 514
 515                         return false;
 516                 }
 517                 else if (ret > 0)
 518                 {
 519                         // Handshake complete.
 520                         VerifyCertificate(session, user);
 521
 522                         session->status = ISSL_OPEN;
 523
 524                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 525
 526                         return true;
 527                 }
 528                 else if (ret == 0)
 529                 {
 530                         CloseSession(session);
 531                         return true;
 532                 }
 533
 534                 return true;
 535         }
 536
 537         void CloseSession(issl_session* session)
 538         {
 539                 if (session->sess)
 540                 {
 541                         SSL_shutdown(session->sess);
 542                         SSL_free(session->sess);
 543                 }
 544
 545                 session->sess = NULL;
 546                 session->status = ISSL_NONE;
 547                 errno = EIO;
 548         }
 549
 550         void VerifyCertificate(issl_session* session, StreamSocket* user)
 551         {
 552                 if (!session->sess || !user || session->cert)
 553                         return;
 554
 555                 X509* cert;
 556                 ssl_cert* certinfo = new ssl_cert;
 557                 session->cert = certinfo;
 558                 unsigned int n;
 559                 unsigned char md[EVP_MAX_MD_SIZE];
 560                 const EVP_MD *digest = use_sha ? EVP_sha1() : EVP_md5();
 561
 562                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 563
 564                 if (!cert)
 565                 {
 566                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 567                         return;
 568                 }
 569
 570                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 571
 572                 if (SelfSigned)
 573                 {
 574                         certinfo->unknownsigner = false;
 575                         certinfo->trusted = true;
 576                 }
 577                 else
 578                 {
 579                         certinfo->unknownsigner = true;
 580                         certinfo->trusted = false;
 581                 }
 582
 583                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 584                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 585
 586                 if (!X509_digest(cert, digest, md, &n))
 587                 {
 588                         certinfo->error = "Out of memory generating fingerprint";
 589                 }
 590                 else
 591                 {
 592                         certinfo->fingerprint = irc::hex(md, n);
 593                 }
 594
 595                 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))
 596                 {
 597                         certinfo->error = "Not activated, or expired certificate";
 598                 }
 599
 600                 X509_free(cert);
 601         }
 602 };
 603
 604 static int error_callback(const char *str, size_t len, void *u)
 605 {
 606         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 607
 608         //
 609         // XXX: Remove this line, it causes valgrind warnings...
 610         //
 611         // MD_update(&m, buf, j);
 612         //
 613         //
 614         // ... ONLY JOKING! :-)
 615         //
 616
 617         return 0;
 618 }
 619
 620 MODULE_INIT(ModuleSSLOpenSSL)