src/modules/m_cloaking.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
   6  *                       E-mail:
   7  *                <brain@chatspike.net>
   8  *                <Craig@chatspike.net>
   9  *
  10  * Written by Craig Edwards, Craig McLure, and others.
  11  * This program is free but copyrighted software; see
  12  *            the file COPYING for details.
  13  *
  14  * ---------------------------------------------------
  15  */
  16
  17 #include "inspircd_config.h"
  18 #include "configreader.h"
  19 #include "inspircd.h"
  20 #include "users.h"
  21 #include "channels.h"
  22 #include "modules.h"
  23
  24 #include "m_md5.h"
  25
  26 /* $ModDesc: Provides masking of user hostnames */
  27
  28 static const char* xtab[] = {"F92E45D871BCA630", "A1B9D80C72E653F4", "1ABC078934DEF562", "ABCDEF5678901234"};
  29
  30 /** Handles user mode +x
  31  */
  32 class CloakUser : public ModeHandler
  33 {
  34
  35         std::string prefix;
  36         unsigned int key1;
  37         unsigned int key2;
  38         unsigned int key3;
  39         unsigned int key4;
  40         Module* Sender;
  41         Module* MD5Provider;
  42
  43  public:
  44         CloakUser(InspIRCd* Instance, Module* Source, Module* MD5) : ModeHandler(Instance, 'x', 0, 0, false, MODETYPE_USER, false), Sender(Source), MD5Provider(MD5)
  45         {
  46         }
  47
  48         ModeAction OnModeChange(userrec* source, userrec* dest, chanrec* channel, std::string &parameter, bool adding)
  49         {
  50                 /* Only opers can change other users modes */
  51                 if ((source != dest) && (!*source->oper))
  52                         return MODEACTION_DENY;
  53
  54                 /* For remote clients, we dont take any action, we just allow it.
  55                  * The local server where they are will set their cloak instead.
  56                  */
  57                 if (!IS_LOCAL(dest))
  58                         return MODEACTION_ALLOW;
  59
  60                 if (adding)
  61                 {
  62                         if(!dest->IsModeSet('x'))
  63                         {
  64                                 /* The mode is being turned on - so attempt to
  65                                  * allocate the user a cloaked host using a non-reversible
  66                                  * algorithm (its simple, but its non-reversible so the
  67                                  * simplicity doesnt really matter). This algorithm
  68                                  * will not work if the user has only one level of domain
  69                                  * naming in their hostname (e.g. if they are on a lan or
  70                                  * are connecting via localhost) -- this doesnt matter much.
  71                                  */
  72
  73                                 if (strchr(dest->host,'.') || strchr(dest->host,':'))
  74                                 {
  75                                         /* InspIRCd users have two hostnames; A displayed
  76                                          * hostname which can be modified by modules (e.g.
  77                                          * to create vhosts, implement chghost, etc) and a
  78                                          * 'real' hostname which you shouldnt write to.
  79                                          */
  80
  81                                         char* n = strstr(dest->host,".");
  82                                         if (!n)
  83                                                 n = strstr(dest->host,":");
  84
  85                                         std::string a = n;
  86
  87                                         std::string b;
  88                                         insp_inaddr testaddr;
  89                                         std::string hostcloak = prefix + "-" + MD5SumRequest(Sender, MD5Provider, dest->host).Send() + a;
  90
  91                                         /* Fix by brain - if the cloaked host is > the max length of a host (64 bytes
  92                                          * according to the DNS RFC) then tough titty, they get cloaked as an IP.
  93                                          * Their ISP shouldnt go to town on subdomains, or they shouldnt have a kiddie
  94                                          * vhost.
  95                                          */
  96
  97                                         if ((insp_aton(dest->host,&testaddr) < 1) && (hostcloak.length() <= 64))
  98                                         {
  99                                                 // if they have a hostname, make something appropriate
 100                                                 b = hostcloak;
 101                                         }
 102                                         else
 103                                         {
 104                                                 b = ((b.find(':') == std::string::npos) ? Cloak4(dest->host) : Cloak6(dest->host));
 105                                         }
 106                                         ServerInstance->Log(DEBUG,"cloak: allocated "+b);
 107                                         dest->ChangeDisplayedHost(b.c_str());
 108                                 }
 109
 110                                 dest->SetMode('x',true);
 111                                 return MODEACTION_ALLOW;
 112                         }
 113                 }
 114                 else
 115                 {
 116                         if (dest->IsModeSet('x'))
 117                         {
 118                                 /* User is removing the mode, so just restore their real host
 119                                  * and make it match the displayed one.
 120                                  */
 121                                 dest->ChangeDisplayedHost(dest->host);
 122                                 dest->SetMode('x',false);
 123                                 return MODEACTION_ALLOW;
 124                         }
 125                 }
 126
 127                 return MODEACTION_DENY;
 128         }
 129
 130         std::string Cloak4(const char* ip)
 131         {
 132                 unsigned int iv[] = { key1, key2, key3, key4 };
 133                 irc::sepstream seps(ip, '.');
 134                 std::string ra1, ra2, ra3, ra4;
 135                 int i1, i2, i3, i4;
 136                 std::string octet1 = seps.GetToken();
 137                 std::string octet2 = seps.GetToken();
 138                 std::string octet3 = seps.GetToken();
 139                 std::string octet4 = seps.GetToken();
 140                 i1 = atoi(octet1.c_str());
 141                 i2 = atoi(octet2.c_str());
 142                 i3 = atoi(octet3.c_str());
 143                 i4 = atoi(octet4.c_str());
 144                 octet4 = octet1 + "." + octet2 + "." + octet3 + "." + octet4;
 145                 octet3 = octet1 + "." + octet2 + "." + octet3;
 146                 octet2 = octet1 + "." + octet2;
 147
 148                 MD5ResetRequest(Sender, MD5Provider).Send();
 149                 MD5KeyRequest(Sender, MD5Provider, iv).Send();
 150
 151                 MD5HexRequest(Sender, MD5Provider, xtab[(key1+i1) % 4]).Send();
 152                 ra1 = std::string(MD5SumRequest(Sender, MD5Provider, octet1).Send()).substr(0,6);
 153
 154                 MD5HexRequest(Sender, MD5Provider, xtab[(key2+i2) % 4]).Send();
 155                 ra2 = std::string(MD5SumRequest(Sender, MD5Provider, octet2).Send()).substr(0,6);
 156
 157                 MD5HexRequest(Sender, MD5Provider, xtab[(key3+i3) % 4]).Send();
 158                 ra3 = std::string(MD5SumRequest(Sender, MD5Provider, octet3).Send()).substr(0,6);
 159
 160                 MD5HexRequest(Sender, MD5Provider, xtab[(key4+i4) % 4]).Send();
 161                 ra4 = std::string(MD5SumRequest(Sender, MD5Provider, octet4).Send()).substr(0,6);
 162
 163                 /* This is safe as we know the length generated by our genhash is always 16 */
 164                 return std::string().append(ra1).append(".").append(ra2).append(".").append(ra3).append(".").append(ra4);
 165         }
 166
 167         std::string Cloak6(const char* ip)
 168         {
 169                 unsigned int iv[] = { key1, key2, key3, key4 };
 170                 std::vector<std::string> hashies;
 171                 std::string item = "";
 172                 int rounds = 0;
 173
 174                 MD5ResetRequest(Sender, MD5Provider).Send();
 175                 MD5KeyRequest(Sender, MD5Provider, iv).Send();
 176
 177                 for (const char* input = ip; *input; input++)
 178                 {
 179                         item += *input;
 180                         if (item.length() > 5)
 181                         {
 182                                 MD5HexRequest(Sender, MD5Provider, xtab[(key1+rounds) % 4]).Send();
 183                                 hashies.push_back(std::string(MD5SumRequest(Sender, MD5Provider, item).Send()).substr(0,10));
 184                                 item = "";
 185                         }
 186                         rounds++;
 187                 }
 188                 if (!item.empty())
 189                 {
 190                         MD5HexRequest(Sender, MD5Provider, xtab[(key1+rounds) % 4]).Send();
 191                         hashies.push_back(std::string(MD5SumRequest(Sender, MD5Provider, item).Send()).substr(0,10));
 192                         item = "";
 193                 }
 194                 return irc::stringjoiner(":", hashies, 0, hashies.size() - 1).GetJoined();
 195         }
 196
 197         /* XXX: Uncomment and call to use the test suite
 198         void TestSuite()
 199         {
 200                 printf("%s %s\n", "192.168.1.1", Cloak4("192.168.1.1").c_str());
 201                 printf("%s %s\n", "192.168.1.2", Cloak4("192.168.1.2").c_str());
 202                 printf("%s %s\n", "192.168.10.1", Cloak4("192.168.10.1").c_str());
 203                 printf("%s %s\n", "192.168.10.1", Cloak4("192.168.10.2").c_str());
 204                 printf("%s %s\n", "192.169.1.1", Cloak4("192.169.1.1").c_str());
 205                 printf("%s %s\n", "192.169.2.1", Cloak4("192.169.2.1").c_str());
 206                 printf("%s %s\n", "200.168.1.1", Cloak4("200.168.1.1").c_str());
 207                 printf("%s %s\n", "200.168.1.3", Cloak4("200.168.1.3").c_str());
 208                 printf("%s %s\n", "200.168.3.3", Cloak4("200.168.3.3").c_str());
 209                 printf("%s %s\n", "200.169.4.3", Cloak4("200.169.4.3").c_str());
 210                 printf("---\n");
 211                 printf("%s %s\n", "9a05:2f00:3f11::5f12::1", Cloak6("9a05:2f00:3f11::5f12::1").c_str());
 212                 printf("%s %s\n", "9a05:2f00:3f11::5f12::2", Cloak6("9a05:2f00:3f11::5f12::2").c_str());
 213                 printf("%s %s\n", "9a05:2f00:3f11::5a12::1", Cloak6("9a05:2f00:3f11::5a12::1").c_str());
 214                 printf("%s %s\n", "9a05:2f00:3f11::5a12::2", Cloak6("9a05:2f00:3f11::5a12::2").c_str());
 215                 printf("%s %s\n", "9a05:3f01:3f11::5f12::1", Cloak6("9a05:3f01:3f11::5f12::1").c_str());
 216                 printf("%s %s\n", "9a05:4f00:3f11::5f13::2", Cloak6("9a05:4f00:3f11::5f13::2").c_str());
 217                 printf("%s %s\n", "ffff:2f00:3f11::5f12::1", Cloak6("ffff:2f00:3f11::5f12::1").c_str());
 218                 printf("%s %s\n", "ffff:2f00:3f11::5f13::2", Cloak6("ffff:2f00:3f11::5f13::2").c_str());
 219                 exit(0);
 220         }
 221         */
 222
 223         void DoRehash()
 224         {
 225                 ConfigReader Conf(ServerInstance);
 226                 key1 = key2 = key3 = key4 = 0;
 227                 key1 = Conf.ReadInteger("cloak","key1",0,false);
 228                 key2 = Conf.ReadInteger("cloak","key2",0,false);
 229                 key3 = Conf.ReadInteger("cloak","key3",0,false);
 230                 key4 = Conf.ReadInteger("cloak","key4",0,false);
 231
 232                 prefix = Conf.ReadValue("cloak","prefix",0);
 233                 if (prefix == "")
 234                 {
 235                         prefix = ServerInstance->Config->Network;
 236                 }
 237                 if (!key1 && !key2 && !key3 && !key4)
 238                 {
 239                         ModuleException ex("You have not defined cloak keys for m_cloaking!!! THIS IS INSECURE AND SHOULD BE CHECKED!");
 240                         throw (ex);
 241                 }
 242         }
 243 };
 244
 245
 246 class ModuleCloaking : public Module
 247 {
 248  private:
 249
 250         CloakUser* cu;
 251         Module* MD5Module;
 252
 253  public:
 254         ModuleCloaking(InspIRCd* Me)
 255                 : Module::Module(Me)
 256         {
 257                 MD5Module = ServerInstance->FindModule("m_md5.so");
 258                 if (!MD5Module)
 259                         throw ModuleException("Can't find m_md5.so. Please load m_md5.so before m_cloaking.so.");
 260
 261                 /* Create new mode handler object */
 262                 cu = new CloakUser(ServerInstance, this, MD5Module);
 263
 264                 /* Register it with the core */
 265                 ServerInstance->AddMode(cu, 'x');
 266
 267                 OnRehash("");
 268         }
 269
 270         virtual ~ModuleCloaking()
 271         {
 272                 ServerInstance->Modes->DelMode(cu);
 273                 DELETE(cu);
 274         }
 275
 276         virtual Version GetVersion()
 277         {
 278                 // returns the version number of the module to be
 279                 // listed in /MODULES
 280                 return Version(1,1,0,2,VF_COMMON|VF_VENDOR,API_VERSION);
 281         }
 282
 283         virtual void OnRehash(const std::string &parameter)
 284         {
 285                 cu->DoRehash();
 286         }
 287
 288         void Implements(char* List)
 289         {
 290                 List[I_OnRehash] = 1;
 291         }
 292 };
 293
 294 // stuff down here is the module-factory stuff. For basic modules you can ignore this.
 295
 296 class ModuleCloakingFactory : public ModuleFactory
 297 {
 298  public:
 299         ModuleCloakingFactory()
 300         {
 301         }
 302
 303         ~ModuleCloakingFactory()
 304         {
 305         }
 306
 307         virtual Module * CreateModule(InspIRCd* Me)
 308         {
 309                 return new ModuleCloaking(Me);
 310         }
 311
 312 };
 313
 314
 315 extern "C" void * init_module( void )
 316 {
 317         return new ModuleCloakingFactory;
 318 }