src/modules/extra/m_ssl_gnutls.cpp

   1 #include <string>
   2 #include <vector>
   3
   4 #include <gnutls/gnutls.h>
   5
   6 #include "inspircd_config.h"
   7 #include "users.h"
   8 #include "channels.h"
   9 #include "modules.h"
  10 #include "helperfuncs.h"
  11 #include "socket.h"
  12 #include "hashcomp.h"
  13
  14 /* $ModDesc: Provides SSL support for clients */
  15 /* $CompileFlags: `libgnutls-config --cflags` */
  16 /* $LinkerFlags: `libgnutls-config --libs` */
  17
  18 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  19
  20 bool isin(int port, const std::vector<int> &portlist)
  21 {
  22         for(unsigned int i = 0; i < portlist.size(); i++)
  23                 if(portlist[i] == port)
  24                         return true;
  25
  26         return false;
  27 }
  28
  29 class issl_session
  30 {
  31 public:
  32         gnutls_session_t sess;
  33         issl_status status;
  34         std::string outbuf;
  35         int inbufoffset;
  36         char* inbuf;
  37         int fd;
  38 };
  39
  40 class ModuleSSLGnuTLS : public Module
  41 {
  42         Server* Srv;
  43         ServerConfig* SrvConf;
  44         ConfigReader* Conf;
  45
  46         CullList culllist;
  47
  48         std::vector<int> listenports;
  49
  50         int inbufsize;
  51         issl_session sessions[MAX_DESCRIPTORS];
  52
  53         gnutls_certificate_credentials x509_cred;
  54         gnutls_dh_params dh_params;
  55
  56         std::string keyfile;
  57         std::string certfile;
  58         std::string cafile;
  59         std::string crlfile;
  60         int dh_bits;
  61
  62  public:
  63
  64         ModuleSSLGnuTLS(Server* Me)
  65                 : Module::Module(Me)
  66         {
  67                 Srv = Me;
  68                 SrvConf = Srv->GetConfig();
  69
  70                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
  71                 inbufsize = SrvConf->NetBufferSize;
  72
  73                 gnutls_global_init(); // This must be called once in the program
  74
  75                 if(gnutls_certificate_allocate_credentials(&x509_cred) != 0)
  76                         log(DEFAULT, "m_ssl_gnutls.so: Failed to allocate certificate credentials");
  77
  78                 // Guessing return meaning
  79                 if(gnutls_dh_params_init(&dh_params) < 0)
  80                         log(DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters");
  81
  82                 // Needs the flag as it ignores a plain /rehash
  83                 OnRehash("ssl");
  84
  85                 // Void return, guess we assume success
  86                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
  87         }
  88
  89         virtual void OnRehash(std::string param)
  90         {
  91                 if(param != "ssl")
  92                         return;
  93
  94                 Conf = new ConfigReader;
  95
  96                 for(unsigned int i = 0; i < listenports.size(); i++)
  97                 {
  98                         SrvConf->DelIOHook(listenports[i]);
  99                 }
 100
 101                 listenports.clear();
 102
 103                 for(int i = 0; i < Conf->Enumerate("bind"); i++)
 104                 {
 105                         // For each <bind> tag
 106                         if(((Conf->ReadValue("bind", "type", i) == "") || (Conf->ReadValue("bind", "type", i) == "clients")) && (Conf->ReadValue("bind", "ssl", i) == "gnutls"))
 107                         {
 108                                 // Get the port we're meant to be listening on with SSL
 109                                 unsigned int port = Conf->ReadInteger("bind", "port", i, true);
 110                                 if(SrvConf->AddIOHook(port, this))
 111                                 {
 112                                         // We keep a record of which ports we're listening on with SSL
 113                                         listenports.push_back(port);
 114
 115                                         log(DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %d", port);
 116                                 }
 117                                 else
 118                                 {
 119                                         log(DEFAULT, "m_ssl_gnutls.so: FAILED to enable SSL on port %d, maybe you have another ssl or similar module loaded?", port);
 120                                 }
 121                         }
 122                 }
 123
 124                 std::string confdir(CONFIG_FILE);
 125                 // +1 so we the path ends with a /
 126                 confdir = confdir.substr(0, confdir.find_last_of('/') + 1);
 127
 128                 cafile  = Conf->ReadValue("gnutls", "cafile", 0);
 129                 crlfile = Conf->ReadValue("gnutls", "crlfile", 0);
 130                 certfile        = Conf->ReadValue("gnutls", "certfile", 0);
 131                 keyfile = Conf->ReadValue("gnutls", "keyfile", 0);
 132                 dh_bits = Conf->ReadInteger("gnutls", "dhbits", 0, false);
 133
 134                 // Set all the default values needed.
 135                 if(cafile == "")
 136                         cafile = "ca.pem";
 137
 138                 if(crlfile == "")
 139                         crlfile = "crl.pem";
 140
 141                 if(certfile == "")
 142                         certfile = "cert.pem";
 143
 144                 if(keyfile == "")
 145                         keyfile = "key.pem";
 146
 147                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 148                         dh_bits = 1024;
 149
 150                 // Prepend relative paths with the path to the config directory.
 151                 if(cafile[0] != '/')
 152                         cafile = confdir + cafile;
 153
 154                 if(crlfile[0] != '/')
 155                         crlfile = confdir + crlfile;
 156
 157                 if(certfile[0] != '/')
 158                         certfile = confdir + certfile;
 159
 160                 if(keyfile[0] != '/')
 161                         keyfile = confdir + keyfile;
 162
 163                 if(gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
 164                         log(DEFAULT, "m_ssl_gnutls.so: Failed to set X.509 trust file: %s", cafile.c_str());
 165
 166                 if(gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
 167                         log(DEFAULT, "m_ssl_gnutls.so: Failed to set X.509 CRL file: %s", crlfile.c_str());
 168
 169                 // Guessing on the return value of this, manual doesn't say :|
 170                 if(gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
 171                         log(DEFAULT, "m_ssl_gnutls.so: Failed to set X.509 certificate and key files: %s and %s", certfile.c_str(), keyfile.c_str());
 172
 173                 // This may be on a large (once a day or week) timer eventually.
 174                 GenerateDHParams();
 175
 176                 delete Conf;
 177         }
 178
 179         void GenerateDHParams()
 180         {
 181                 // Generate Diffie Hellman parameters - for use with DHE
 182                 // kx algorithms. These should be discarded and regenerated
 183                 // once a day, once a week or once a month. Depending on the
 184                 // security requirements.
 185
 186                 if(gnutls_dh_params_generate2(dh_params, dh_bits) < 0)
 187                         log(DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits)", dh_bits);
 188         }
 189
 190         virtual ~ModuleSSLGnuTLS()
 191         {
 192                 gnutls_dh_params_deinit(dh_params);
 193                 gnutls_certificate_free_credentials(x509_cred);
 194                 gnutls_global_deinit();
 195         }
 196
 197         virtual void OnCleanup(int target_type, void* item)
 198         {
 199                 if(target_type == TYPE_USER)
 200                 {
 201                         userrec* user = (userrec*)item;
 202
 203                         if(user->GetExt("ssl") && IS_LOCAL(user) && isin(user->port, listenports))
 204                         {
 205                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 206                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 207                                 log(DEBUG, "m_ssl_gnutls.so: Adding user %s to cull list", user->nick);
 208                                 culllist.AddItem(user, "SSL module unloading");
 209                         }
 210                 }
 211         }
 212
 213         virtual void OnUnloadModule(Module* mod, std::string name)
 214         {
 215                 if(mod == this)
 216                 {
 217                         // We're being unloaded, kill all the users added to the cull list in OnCleanup
 218                         int numusers = culllist.Apply();
 219                         log(DEBUG, "m_ssl_gnutls.so: Killed %d users for unload of GnuTLS SSL module", numusers);
 220
 221                         for(unsigned int i = 0; i < listenports.size(); i++)
 222                                 SrvConf->DelIOHook(listenports[i]);
 223                 }
 224         }
 225
 226         virtual Version GetVersion()
 227         {
 228                 return Version(1, 0, 0, 0, VF_VENDOR);
 229         }
 230
 231         void Implements(char* List)
 232         {
 233                 List[I_OnRawSocketAccept] = List[I_OnRawSocketClose] = List[I_OnRawSocketRead] = List[I_OnRawSocketWrite] = List[I_OnCleanup] = 1;
 234                 List[I_OnSyncUserMetaData] = List[I_OnDecodeMetaData] = List[I_OnUnloadModule] = List[I_OnRehash] = List[I_OnWhois] = List[I_OnGlobalConnect] = 1;
 235         }
 236
 237         virtual void OnRawSocketAccept(int fd, std::string ip, int localport)
 238         {
 239                 issl_session* session = &sessions[fd];
 240
 241                 session->fd = fd;
 242                 session->inbuf = new char[inbufsize];
 243                 session->inbufoffset = 0;
 244
 245                 gnutls_init(&session->sess, GNUTLS_SERVER);
 246
 247                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 248                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 249                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 250                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 251                 gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 252
 253                 Handshake(session);
 254         }
 255
 256         virtual void OnRawSocketClose(int fd)
 257         {
 258                 log(DEBUG, "OnRawSocketClose: %d", fd);
 259                 CloseSession(&sessions[fd]);
 260         }
 261
 262         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 263         {
 264                 issl_session* session = &sessions[fd];
 265
 266                 if(!session->sess)
 267                 {
 268                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: No session to read from");
 269                         readresult = 0;
 270                         CloseSession(session);
 271                         return 1;
 272                 }
 273
 274                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead(%d, buffer, %u, %d)", fd, count, readresult);
 275
 276                 if(session->status == ISSL_HANDSHAKING_READ)
 277                 {
 278                         // The handshake isn't finished, try to finish it.
 279
 280                         if(Handshake(session))
 281                         {
 282                                 // Handshake successfully resumed.
 283                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: successfully resumed handshake");
 284                         }
 285                         else
 286                         {
 287                                 // Couldn't resume handshake.
 288                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: failed to resume handshake");
 289                                 return -1;
 290                         }
 291                 }
 292                 else if(session->status == ISSL_HANDSHAKING_WRITE)
 293                 {
 294                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: handshake wants to write data but we are currently reading");
 295                         return -1;
 296                 }
 297
 298                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 299
 300                 if(session->status == ISSL_HANDSHAKEN)
 301                 {
 302                         // Is this right? Not sure if the unencrypted data is garaunteed to be the same length.
 303                         // Read into the inbuffer, offset from the beginning by the amount of data we have that insp hasn't taken yet.
 304                         log(DEBUG, "m_ssl_gnutls.so: gnutls_record_recv(sess, inbuf+%d, %d-%d)", session->inbufoffset, inbufsize, session->inbufoffset);
 305
 306                         int ret = gnutls_record_recv(session->sess, session->inbuf + session->inbufoffset, inbufsize - session->inbufoffset);
 307
 308                         if(ret == 0)
 309                         {
 310                                 // Client closed connection.
 311                                 log(DEBUG, "m_ssl_gnutls.so: Client closed the connection");
 312                                 readresult = 0;
 313                                 CloseSession(session);
 314                                 return 1;
 315                         }
 316                         else if(ret < 0)
 317                         {
 318                                 if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 319                                 {
 320                                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Not all SSL data read: %s", gnutls_strerror(ret));
 321                                         return -1;
 322                                 }
 323                                 else
 324                                 {
 325                                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Error reading SSL data: %s", gnutls_strerror(ret));
 326                                         readresult = 0;
 327                                         CloseSession(session);
 328                                 }
 329                         }
 330                         else
 331                         {
 332                                 // Read successfully 'ret' bytes into inbuf + inbufoffset
 333                                 // There are 'ret' + 'inbufoffset' bytes of data in 'inbuf'
 334                                 // 'buffer' is 'count' long
 335
 336                                 unsigned int length = ret + session->inbufoffset;
 337
 338                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Read %d bytes, now have %d waiting to be passed up", ret, length);
 339
 340                                 if(count <= length)
 341                                 {
 342                                         memcpy(buffer, session->inbuf, count);
 343                                         // Move the stuff left in inbuf to the beginning of it
 344                                         memcpy(session->inbuf, session->inbuf + count, (length - count));
 345                                         // Now we need to set session->inbufoffset to the amount of data still waiting to be handed to insp.
 346                                         session->inbufoffset = length - count;
 347                                         // Insp uses readresult as the count of how much data there is in buffer, so:
 348                                         readresult = count;
 349                                 }
 350                                 else
 351                                 {
 352                                         // There's not as much in the inbuf as there is space in the buffer, so just copy the whole thing.
 353                                         memcpy(buffer, session->inbuf, length);
 354                                         // Zero the offset, as there's nothing there..
 355                                         session->inbufoffset = 0;
 356                                         // As above
 357                                         readresult = length;
 358                                 }
 359
 360                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Passing %d bytes up to insp:");
 361                                 Srv->Log(DEBUG, std::string(buffer, readresult));
 362                         }
 363                 }
 364                 else if(session->status == ISSL_CLOSING)
 365                 {
 366                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: session closing...");
 367                         readresult = 0;
 368                 }
 369
 370                 return 1;
 371         }
 372
 373         virtual int OnRawSocketWrite(int fd, char* buffer, int count)
 374         {
 375                 issl_session* session = &sessions[fd];
 376                 const char* sendbuffer = buffer;
 377
 378                 if(!session->sess)
 379                 {
 380                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: No session to write to");
 381                         CloseSession(session);
 382                         return 1;
 383                 }
 384
 385                 if(session->status == ISSL_HANDSHAKING_WRITE)
 386                 {
 387                         // The handshake isn't finished, try to finish it.
 388
 389                         if(Handshake(session))
 390                         {
 391                                 // Handshake successfully resumed.
 392                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: successfully resumed handshake");
 393                         }
 394                         else
 395                         {
 396                                 // Couldn't resume handshake.
 397                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: failed to resume handshake");
 398                         }
 399                 }
 400                 else if(session->status == ISSL_HANDSHAKING_READ)
 401                 {
 402                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: handshake wants to read data but we are currently writing");
 403                 }
 404
 405                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Adding %d bytes to the outgoing buffer", count);
 406                 session->outbuf.append(sendbuffer, count);
 407                 sendbuffer = session->outbuf.c_str();
 408                 count = session->outbuf.size();
 409
 410                 if(session->status == ISSL_HANDSHAKEN)
 411                 {
 412                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Trying to write %d bytes:", count);
 413                         Srv->Log(DEBUG, session->outbuf);
 414
 415                         int ret = gnutls_record_send(session->sess, sendbuffer, count);
 416
 417                         if(ret == 0)
 418                         {
 419                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Client closed the connection");
 420                                 CloseSession(session);
 421                         }
 422                         else if(ret < 0)
 423                         {
 424                                 if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 425                                 {
 426                                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Not all SSL data written: %s", gnutls_strerror(ret));
 427                                 }
 428                                 else
 429                                 {
 430                                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Error writing SSL data: %s", gnutls_strerror(ret));
 431                                         CloseSession(session);
 432                                 }
 433                         }
 434                         else
 435                         {
 436                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Successfully wrote %d bytes", ret);
 437                                 session->outbuf = session->outbuf.substr(ret);
 438                         }
 439                 }
 440                 else if(session->status == ISSL_CLOSING)
 441                 {
 442                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: session closing...");
 443                 }
 444
 445                 return 1;
 446         }
 447
 448         // :kenny.chatspike.net 320 Om Epy|AFK :is a Secure Connection
 449         virtual void OnWhois(userrec* source, userrec* dest)
 450         {
 451                 // Bugfix, only send this numeric for *our* SSL users
 452                 if(dest->GetExt("ssl") && isin(dest->port, listenports))
 453                 {
 454                         WriteServ(source->fd, "320 %s %s :is using a secure connection", source->nick, dest->nick);
 455                 }
 456         }
 457
 458         virtual void OnSyncUserMetaData(userrec* user, Module* proto, void* opaque, std::string extname)
 459         {
 460                 // check if the linking module wants to know about OUR metadata
 461                 if(extname == "ssl")
 462                 {
 463                         // check if this user has an swhois field to send
 464                         if(user->GetExt(extname))
 465                         {
 466                                 // call this function in the linking module, let it format the data how it
 467                                 // sees fit, and send it on its way. We dont need or want to know how.
 468                                 proto->ProtoSendMetaData(opaque, TYPE_USER, user, extname, "ON");
 469                         }
 470                 }
 471         }
 472
 473         virtual void OnDecodeMetaData(int target_type, void* target, std::string extname, std::string extdata)
 474         {
 475                 // check if its our metadata key, and its associated with a user
 476                 if ((target_type == TYPE_USER) && (extname == "ssl"))
 477                 {
 478                         userrec* dest = (userrec*)target;
 479                         // if they dont already have an ssl flag, accept the remote server's
 480                         if (!dest->GetExt(extname))
 481                         {
 482                                 dest->Extend(extname, "ON");
 483                         }
 484                 }
 485         }
 486
 487         bool Handshake(issl_session* session)
 488         {
 489                 int ret = gnutls_handshake(session->sess);
 490
 491       if(ret < 0)
 492                 {
 493                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 494                         {
 495                                 // Handshake needs resuming later, read() or write() would have blocked.
 496
 497                                 if(gnutls_record_get_direction(session->sess) == 0)
 498                                 {
 499                                         // gnutls_handshake() wants to read() again.
 500                                         session->status = ISSL_HANDSHAKING_READ;
 501                                         log(DEBUG, "m_ssl_gnutls.so: Handshake needs resuming (reading) later, error string: %s", gnutls_strerror(ret));
 502                                 }
 503                                 else
 504                                 {
 505                                         // gnutls_handshake() wants to write() again.
 506                                         session->status = ISSL_HANDSHAKING_WRITE;
 507                                         log(DEBUG, "m_ssl_gnutls.so: Handshake needs resuming (writing) later, error string: %s", gnutls_strerror(ret));
 508                                         MakePollWrite(session);
 509                                 }
 510                         }
 511                         else
 512                         {
 513                                 // Handshake failed.
 514                                 CloseSession(session);
 515                            log(DEBUG, "m_ssl_gnutls.so: Handshake failed, error string: %s", gnutls_strerror(ret));
 516                            session->status = ISSL_CLOSING;
 517                         }
 518
 519                         return false;
 520                 }
 521                 else
 522                 {
 523                         // Handshake complete.
 524                         log(DEBUG, "m_ssl_gnutls.so: Handshake completed");
 525
 526                         // This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
 527                         userrec* extendme = Srv->FindDescriptor(session->fd);
 528                         extendme->Extend("ssl", "ON");
 529
 530                         // Change the seesion state
 531                         session->status = ISSL_HANDSHAKEN;
 532
 533                         // Finish writing, if any left
 534                         MakePollWrite(session);
 535
 536                         return true;
 537                 }
 538         }
 539
 540         virtual void OnGlobalConnect(userrec* user)
 541         {
 542                 // This occurs AFTER OnUserConnect so we can be sure the
 543                 // protocol module has propogated the NICK message.
 544                 if ((user->GetExt("ssl")) && (IS_LOCAL(user)))
 545                 {
 546                         // Tell whatever protocol module we're using that we need to inform other servers of this metadata NOW.
 547                         std::deque<std::string>* metadata = new std::deque<std::string>;
 548                         metadata->push_back(user->nick);
 549                         metadata->push_back("ssl");             // The metadata id
 550                         metadata->push_back("ON");              // The value to send
 551                         Event* event = new Event((char*)metadata,(Module*)this,"send_metadata");
 552                         event->Send();                          // Trigger the event. We don't care what module picks it up.
 553                         delete event;
 554                         delete metadata;
 555                 }
 556         }
 557
 558         void MakePollWrite(issl_session* session)
 559         {
 560                 OnRawSocketWrite(session->fd, NULL, 0);
 561         }
 562
 563         void CloseSession(issl_session* session)
 564         {
 565                 if(session->sess)
 566                 {
 567                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 568                         gnutls_deinit(session->sess);
 569                 }
 570
 571                 if(session->inbuf)
 572                 {
 573                         delete[] session->inbuf;
 574                 }
 575
 576                 session->outbuf.clear();
 577                 session->inbuf = NULL;
 578                 session->sess = NULL;
 579                 session->status = ISSL_NONE;
 580         }
 581 };
 582
 583 class ModuleSSLGnuTLSFactory : public ModuleFactory
 584 {
 585  public:
 586         ModuleSSLGnuTLSFactory()
 587         {
 588         }
 589
 590         ~ModuleSSLGnuTLSFactory()
 591         {
 592         }
 593
 594         virtual Module * CreateModule(Server* Me)
 595         {
 596                 return new ModuleSSLGnuTLS(Me);
 597         }
 598 };
 599
 600
 601 extern "C" void * init_module( void )
 602 {
 603         return new ModuleSSLGnuTLSFactory;
 604 }
 605