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 sslports;
  93         bool use_sha;
  94
  95         ServiceProvider iohook;
  96  public:
  97
  98         ModuleSSLOpenSSL() : iohook(this, "ssl/openssl", SERVICE_IOHOOK)
  99         {
 100                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 101
 102                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 103                 inbufsize = ServerInstance->Config->NetBufferSize;
 104
 105                 /* Global SSL library initialization*/
 106                 SSL_library_init();
 107                 SSL_load_error_strings();
 108
 109                 /* Build our SSL contexts:
 110                  * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
 111                  */
 112                 ctx = SSL_CTX_new( SSLv23_server_method() );
 113                 clictx = SSL_CTX_new( SSLv23_client_method() );
 114
 115                 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 116                 SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 117
 118                 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 119                 SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 120         }
 121
 122         void init()
 123         {
 124                 // Needs the flag as it ignores a plain /rehash
 125                 OnModuleRehash(NULL,"ssl");
 126                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnHookIO, I_OnUserConnect };
 127                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 128                 ServerInstance->Modules->AddService(iohook);
 129         }
 130
 131         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 132         {
 133                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "openssl")
 134                 {
 135                         /* Hook the user with our module */
 136                         user->AddIOHook(this);
 137                 }
 138         }
 139
 140         void OnRehash(User* user)
 141         {
 142                 ConfigReader Conf;
 143
 144                 sslports.clear();
 145
 146                 for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 147                 {
 148                         ListenSocket* port = ServerInstance->ports[i];
 149                         if (port->bind_tag->getString("ssl") != "openssl")
 150                                 continue;
 151
 152                         std::string portid = port->bind_desc;
 153                         ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 154                         if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 155                                 sslports.append(portid).append(";");
 156                 }
 157
 158                 if (!sslports.empty())
 159                         sslports.erase(sslports.end() - 1);
 160         }
 161
 162         void OnModuleRehash(User* user, const std::string &param)
 163         {
 164                 if (param != "ssl")
 165                         return;
 166
 167                 std::string keyfile;
 168                 std::string certfile;
 169                 std::string cafile;
 170                 std::string dhfile;
 171                 OnRehash(user);
 172
 173                 ConfigTag* conf = ServerInstance->Config->ConfValue("openssl");
 174
 175                 cafile   = conf->getString("cafile", "conf/ca.pem");
 176                 certfile = conf->getString("certfile", "conf/cert.pem");
 177                 keyfile  = conf->getString("keyfile", "conf/key.pem");
 178                 dhfile   = conf->getString("dhfile", "conf/dhparams.pem");
 179                 std::string hash = conf->getString("hash", "md5");
 180                 if (hash != "sha1" && hash != "md5")
 181                         throw ModuleException("Unknown hash type " + hash);
 182                 use_sha = (hash == "sha1");
 183
 184
 185                 /* Load our keys and certificates
 186                  * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 187                  */
 188                 if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
 189                 {
 190                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
 191                         ERR_print_errors_cb(error_callback, this);
 192                 }
 193
 194                 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)))
 195                 {
 196                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
 197                         ERR_print_errors_cb(error_callback, this);
 198                 }
 199
 200                 /* Load the CAs we trust*/
 201                 if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
 202                 {
 203                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
 204                         ERR_print_errors_cb(error_callback, this);
 205                 }
 206
 207                 FILE* dhpfile = fopen(dhfile.c_str(), "r");
 208                 DH* ret;
 209
 210                 if (dhpfile == NULL)
 211                 {
 212                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
 213                         throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
 214                 }
 215                 else
 216                 {
 217                         ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
 218                         if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
 219                         {
 220                                 ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
 221                                 ERR_print_errors_cb(error_callback, this);
 222                         }
 223                 }
 224
 225                 fclose(dhpfile);
 226         }
 227
 228         void On005Numeric(std::string &output)
 229         {
 230                 if (!sslports.empty())
 231                         output.append(" SSL=" + sslports);
 232         }
 233
 234         ~ModuleSSLOpenSSL()
 235         {
 236                 SSL_CTX_free(ctx);
 237                 SSL_CTX_free(clictx);
 238                 delete[] sessions;
 239         }
 240
 241         void OnUserConnect(LocalUser* user)
 242         {
 243                 if (user->eh.GetIOHook() == this)
 244                 {
 245                         if (sessions[user->GetFd()].sess)
 246                         {
 247                                 SSLCertSubmission(user, this, ServerInstance->Modules->Find("m_sslinfo.so"), sessions[user->GetFd()].cert);
 248
 249                                 if (!sessions[user->GetFd()].cert->fingerprint.empty())
 250                                         user->WriteServ("NOTICE %s :*** You are connected using SSL fingerprint %s",
 251                                                 user->nick.c_str(), sessions[user->GetFd()].cert->fingerprint.c_str());
 252                         }
 253                 }
 254         }
 255
 256         void OnCleanup(int target_type, void* item)
 257         {
 258                 if (target_type == TYPE_USER)
 259                 {
 260                         LocalUser* user = IS_LOCAL((User*)item);
 261
 262                         if (user && user->eh.GetIOHook() == this)
 263                         {
 264                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 265                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 266                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 267                         }
 268                 }
 269         }
 270
 271         Version GetVersion()
 272         {
 273                 return Version("Provides SSL support for clients", VF_VENDOR);
 274         }
 275
 276         void OnRequest(Request& request)
 277         {
 278                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 279                 {
 280                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 281                         int fd = req.sock->GetFd();
 282                         issl_session* session = &sessions[fd];
 283
 284                         req.cert = session->cert;
 285                 }
 286         }
 287
 288         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 289         {
 290                 int fd = user->GetFd();
 291
 292                 issl_session* session = &sessions[fd];
 293
 294                 session->fd = fd;
 295                 session->sess = SSL_new(ctx);
 296                 session->status = ISSL_NONE;
 297                 session->outbound = false;
 298
 299                 if (session->sess == NULL)
 300                         return;
 301
 302                 if (SSL_set_fd(session->sess, fd) == 0)
 303                 {
 304                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 305                         return;
 306                 }
 307
 308                 Handshake(user, session);
 309         }
 310
 311         void OnStreamSocketConnect(StreamSocket* user)
 312         {
 313                 int fd = user->GetFd();
 314                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 315                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 316                         return;
 317
 318                 issl_session* session = &sessions[fd];
 319
 320                 session->fd = fd;
 321                 session->sess = SSL_new(clictx);
 322                 session->status = ISSL_NONE;
 323                 session->outbound = true;
 324
 325                 if (session->sess == NULL)
 326                         return;
 327
 328                 if (SSL_set_fd(session->sess, fd) == 0)
 329                 {
 330                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 331                         return;
 332                 }
 333
 334                 Handshake(user, session);
 335         }
 336
 337         void OnStreamSocketClose(StreamSocket* user)
 338         {
 339                 int fd = user->GetFd();
 340                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 341                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 342                         return;
 343
 344                 CloseSession(&sessions[fd]);
 345         }
 346
 347         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 348         {
 349                 int fd = user->GetFd();
 350                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 351                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 352                         return -1;
 353
 354                 issl_session* session = &sessions[fd];
 355
 356                 if (!session->sess)
 357                 {
 358                         CloseSession(session);
 359                         return -1;
 360                 }
 361
 362                 if (session->status == ISSL_HANDSHAKING)
 363                 {
 364                         // The handshake isn't finished and it wants to read, try to finish it.
 365                         if (!Handshake(user, session))
 366                         {
 367                                 // Couldn't resume handshake.
 368                                 if (session->status == ISSL_NONE)
 369                                         return -1;
 370                                 return 0;
 371                         }
 372                 }
 373
 374                 // If we resumed the handshake then session->status will be ISSL_OPEN
 375
 376                 if (session->status == ISSL_OPEN)
 377                 {
 378                         char* buffer = ServerInstance->GetReadBuffer();
 379                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 380                         int ret = SSL_read(session->sess, buffer, bufsiz);
 381
 382                         if (ret > 0)
 383                         {
 384                                 recvq.append(buffer, ret);
 385                                 return 1;
 386                         }
 387                         else if (ret == 0)
 388                         {
 389                                 // Client closed connection.
 390                                 CloseSession(session);
 391                                 return -1;
 392                         }
 393                         else if (ret < 0)
 394                         {
 395                                 int err = SSL_get_error(session->sess, ret);
 396
 397                                 if (err == SSL_ERROR_WANT_READ)
 398                                 {
 399                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 400                                         return 0;
 401                                 }
 402                                 else if (err == SSL_ERROR_WANT_WRITE)
 403                                 {
 404                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 405                                         return 0;
 406                                 }
 407                                 else
 408                                 {
 409                                         CloseSession(session);
 410                                         return -1;
 411                                 }
 412                         }
 413                 }
 414
 415                 return 0;
 416         }
 417
 418         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 419         {
 420                 int fd = user->GetFd();
 421
 422                 issl_session* session = &sessions[fd];
 423
 424                 if (!session->sess)
 425                 {
 426                         CloseSession(session);
 427                         return -1;
 428                 }
 429
 430                 session->data_to_write = true;
 431
 432                 if (session->status == ISSL_HANDSHAKING)
 433                 {
 434                         if (!Handshake(user, session))
 435                         {
 436                                 // Couldn't resume handshake.
 437                                 if (session->status == ISSL_NONE)
 438                                         return -1;
 439                                 return 0;
 440                         }
 441                 }
 442
 443                 if (session->status == ISSL_OPEN)
 444                 {
 445                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 446                         if (ret == (int)buffer.length())
 447                         {
 448                                 session->data_to_write = false;
 449                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 450                                 return 1;
 451                         }
 452                         else if (ret > 0)
 453                         {
 454                                 buffer = buffer.substr(ret);
 455                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 456                                 return 0;
 457                         }
 458                         else if (ret == 0)
 459                         {
 460                                 CloseSession(session);
 461                                 return -1;
 462                         }
 463                         else if (ret < 0)
 464                         {
 465                                 int err = SSL_get_error(session->sess, ret);
 466
 467                                 if (err == SSL_ERROR_WANT_WRITE)
 468                                 {
 469                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 470                                         return 0;
 471                                 }
 472                                 else if (err == SSL_ERROR_WANT_READ)
 473                                 {
 474                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 475                                         return 0;
 476                                 }
 477                                 else
 478                                 {
 479                                         CloseSession(session);
 480                                         return -1;
 481                                 }
 482                         }
 483                 }
 484                 return 0;
 485         }
 486
 487         bool Handshake(StreamSocket* user, issl_session* session)
 488         {
 489                 int ret;
 490
 491                 if (session->outbound)
 492                         ret = SSL_connect(session->sess);
 493                 else
 494                         ret = SSL_accept(session->sess);
 495
 496                 if (ret < 0)
 497                 {
 498                         int err = SSL_get_error(session->sess, ret);
 499
 500                         if (err == SSL_ERROR_WANT_READ)
 501                         {
 502                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 503                                 session->status = ISSL_HANDSHAKING;
 504                                 return true;
 505                         }
 506                         else if (err == SSL_ERROR_WANT_WRITE)
 507                         {
 508                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 509                                 session->status = ISSL_HANDSHAKING;
 510                                 return true;
 511                         }
 512                         else
 513                         {
 514                                 CloseSession(session);
 515                         }
 516
 517                         return false;
 518                 }
 519                 else if (ret > 0)
 520                 {
 521                         // Handshake complete.
 522                         VerifyCertificate(session, user);
 523
 524                         session->status = ISSL_OPEN;
 525
 526                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 527
 528                         return true;
 529                 }
 530                 else if (ret == 0)
 531                 {
 532                         CloseSession(session);
 533                         return true;
 534                 }
 535
 536                 return true;
 537         }
 538
 539         void CloseSession(issl_session* session)
 540         {
 541                 if (session->sess)
 542                 {
 543                         SSL_shutdown(session->sess);
 544                         SSL_free(session->sess);
 545                 }
 546
 547                 session->sess = NULL;
 548                 session->status = ISSL_NONE;
 549                 errno = EIO;
 550         }
 551
 552         void VerifyCertificate(issl_session* session, StreamSocket* user)
 553         {
 554                 if (!session->sess || !user || session->cert)
 555                         return;
 556
 557                 X509* cert;
 558                 ssl_cert* certinfo = new ssl_cert;
 559                 session->cert = certinfo;
 560                 unsigned int n;
 561                 unsigned char md[EVP_MAX_MD_SIZE];
 562                 const EVP_MD *digest = use_sha ? EVP_sha1() : EVP_md5();
 563
 564                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 565
 566                 if (!cert)
 567                 {
 568                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 569                         return;
 570                 }
 571
 572                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 573
 574                 if (SelfSigned)
 575                 {
 576                         certinfo->unknownsigner = false;
 577                         certinfo->trusted = true;
 578                 }
 579                 else
 580                 {
 581                         certinfo->unknownsigner = true;
 582                         certinfo->trusted = false;
 583                 }
 584
 585                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 586                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 587
 588                 if (!X509_digest(cert, digest, md, &n))
 589                 {
 590                         certinfo->error = "Out of memory generating fingerprint";
 591                 }
 592                 else
 593                 {
 594                         certinfo->fingerprint = irc::hex(md, n);
 595                 }
 596
 597                 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))
 598                 {
 599                         certinfo->error = "Not activated, or expired certificate";
 600                 }
 601
 602                 X509_free(cert);
 603         }
 604 };
 605
 606 static int error_callback(const char *str, size_t len, void *u)
 607 {
 608         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 609
 610         //
 611         // XXX: Remove this line, it causes valgrind warnings...
 612         //
 613         // MD_update(&m, buf, j);
 614         //
 615         //
 616         // ... ONLY JOKING! :-)
 617         //
 618
 619         return 0;
 620 }
 621
 622 MODULE_INIT(ModuleSSLOpenSSL)