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