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 /* $ModDep: m_md5.h */
  28
  29 static const char* xtab[] = {"F92E45D871BCA630", "A1B9D80C72E653F4", "1ABC078934DEF562", "ABCDEF5678901234"};
  30
  31 /** Handles user mode +x
  32  */
  33 class CloakUser : public ModeHandler
  34 {
  35
  36         std::string prefix;
  37         unsigned int key1;
  38         unsigned int key2;
  39         unsigned int key3;
  40         unsigned int key4;
  41         Module* Sender;
  42         Module* MD5Provider;
  43
  44  public:
  45         CloakUser(InspIRCd* Instance, Module* Source, Module* MD5) : ModeHandler(Instance, 'x', 0, 0, false, MODETYPE_USER, false), Sender(Source), MD5Provider(MD5)
  46         {
  47         }
  48
  49         ModeAction OnModeChange(userrec* source, userrec* dest, chanrec* channel, std::string &parameter, bool adding)
  50         {
  51                 /* Only opers can change other users modes */
  52                 if ((source != dest) && (!*source->oper))
  53                         return MODEACTION_DENY;
  54
  55                 /* For remote clients, we dont take any action, we just allow it.
  56                  * The local server where they are will set their cloak instead.
  57                  */
  58                 if (!IS_LOCAL(dest))
  59                         return MODEACTION_ALLOW;
  60
  61                 if (adding)
  62                 {
  63                         if(!dest->IsModeSet('x'))
  64                         {
  65                                 /* The mode is being turned on - so attempt to
  66                                  * allocate the user a cloaked host using a non-reversible
  67                                  * algorithm (its simple, but its non-reversible so the
  68                                  * simplicity doesnt really matter). This algorithm
  69                                  * will not work if the user has only one level of domain
  70                                  * naming in their hostname (e.g. if they are on a lan or
  71                                  * are connecting via localhost) -- this doesnt matter much.
  72                                  */
  73
  74                                 if (strchr(dest->host,'.') || strchr(dest->host,':'))
  75                                 {
  76                                         /* InspIRCd users have two hostnames; A displayed
  77                                          * hostname which can be modified by modules (e.g.
  78                                          * to create vhosts, implement chghost, etc) and a
  79                                          * 'real' hostname which you shouldnt write to.
  80                                          */
  81
  82                                         char* n = strstr(dest->host,".");
  83                                         if (!n)
  84                                                 n = strstr(dest->host,":");
  85
  86                                         std::string a = n;
  87
  88                                         std::string b;
  89                                         insp_inaddr testaddr;
  90                                         std::string hostcloak = prefix + "-" + MD5SumRequest(Sender, MD5Provider, dest->host).Send() + a;
  91
  92                                         /* Fix by brain - if the cloaked host is > the max length of a host (64 bytes
  93                                          * according to the DNS RFC) then tough titty, they get cloaked as an IP.
  94                                          * Their ISP shouldnt go to town on subdomains, or they shouldnt have a kiddie
  95                                          * vhost.
  96                                          */
  97
  98                                         if ((insp_aton(dest->host,&testaddr) < 1) && (hostcloak.length() <= 64))
  99                                         {
 100                                                 // if they have a hostname, make something appropriate
 101                                                 b = hostcloak;
 102                                         }
 103                                         else
 104                                         {
 105                                                 b = ((b.find(':') == std::string::npos) ? Cloak4(dest->host) : Cloak6(dest->host));
 106                                         }
 107                                         ServerInstance->Log(DEBUG,"cloak: allocated "+b);
 108                                         dest->ChangeDisplayedHost(b.c_str());
 109                                 }
 110
 111                                 dest->SetMode('x',true);
 112                                 return MODEACTION_ALLOW;
 113                         }
 114                 }
 115                 else
 116                 {
 117                         if (dest->IsModeSet('x'))
 118                         {
 119                                 /* User is removing the mode, so just restore their real host
 120                                  * and make it match the displayed one.
 121                                  */
 122                                 dest->ChangeDisplayedHost(dest->host);
 123                                 dest->SetMode('x',false);
 124                                 return MODEACTION_ALLOW;
 125                         }
 126                 }
 127
 128                 return MODEACTION_DENY;
 129         }
 130
 131         std::string Cloak4(const char* ip)
 132         {
 133                 unsigned int iv[] = { key1, key2, key3, key4 };
 134                 irc::sepstream seps(ip, '.');
 135                 std::string ra1, ra2, ra3, ra4;
 136                 int i1, i2, i3, i4;
 137                 std::string octet1 = seps.GetToken();
 138                 std::string octet2 = seps.GetToken();
 139                 std::string octet3 = seps.GetToken();
 140                 std::string octet4 = seps.GetToken();
 141                 i1 = atoi(octet1.c_str());
 142                 i2 = atoi(octet2.c_str());
 143                 i3 = atoi(octet3.c_str());
 144                 i4 = atoi(octet4.c_str());
 145                 octet4 = octet1 + "." + octet2 + "." + octet3 + "." + octet4;
 146                 octet3 = octet1 + "." + octet2 + "." + octet3;
 147                 octet2 = octet1 + "." + octet2;
 148
 149                 MD5ResetRequest(Sender, MD5Provider).Send();
 150                 MD5KeyRequest(Sender, MD5Provider, iv).Send();
 151
 152                 MD5HexRequest(Sender, MD5Provider, xtab[(key1+i1) % 4]).Send();
 153                 ra1 = std::string(MD5SumRequest(Sender, MD5Provider, octet1).Send()).substr(0,6);
 154
 155                 MD5HexRequest(Sender, MD5Provider, xtab[(key2+i2) % 4]).Send();
 156                 ra2 = std::string(MD5SumRequest(Sender, MD5Provider, octet2).Send()).substr(0,6);
 157
 158                 MD5HexRequest(Sender, MD5Provider, xtab[(key3+i3) % 4]).Send();
 159                 ra3 = std::string(MD5SumRequest(Sender, MD5Provider, octet3).Send()).substr(0,6);
 160
 161                 MD5HexRequest(Sender, MD5Provider, xtab[(key4+i4) % 4]).Send();
 162                 ra4 = std::string(MD5SumRequest(Sender, MD5Provider, octet4).Send()).substr(0,6);
 163
 164                 /* This is safe as we know the length generated by our genhash is always 16 */
 165                 return std::string().append(ra1).append(".").append(ra2).append(".").append(ra3).append(".").append(ra4);
 166         }
 167
 168         std::string Cloak6(const char* ip)
 169         {
 170                 unsigned int iv[] = { key1, key2, key3, key4 };
 171                 std::vector<std::string> hashies;
 172                 std::string item = "";
 173                 int rounds = 0;
 174
 175                 MD5ResetRequest(Sender, MD5Provider).Send();
 176                 MD5KeyRequest(Sender, MD5Provider, iv).Send();
 177
 178                 for (const char* input = ip; *input; input++)
 179                 {
 180                         item += *input;
 181                         if (item.length() > 5)
 182                         {
 183                                 MD5HexRequest(Sender, MD5Provider, xtab[(key1+rounds) % 4]).Send();
 184                                 hashies.push_back(std::string(MD5SumRequest(Sender, MD5Provider, item).Send()).substr(0,10));
 185                                 item = "";
 186                         }
 187                         rounds++;
 188                 }
 189                 if (!item.empty())
 190                 {
 191                         MD5HexRequest(Sender, MD5Provider, xtab[(key1+rounds) % 4]).Send();
 192                         hashies.push_back(std::string(MD5SumRequest(Sender, MD5Provider, item).Send()).substr(0,10));
 193                         item = "";
 194                 }
 195                 return irc::stringjoiner(":", hashies, 0, hashies.size() - 1).GetJoined();
 196         }
 197
 198         /* XXX: Uncomment and call to use the test suite
 199         void TestSuite()
 200         {
 201                 printf("%s %s\n", "192.168.1.1", Cloak4("192.168.1.1").c_str());
 202                 printf("%s %s\n", "192.168.1.2", Cloak4("192.168.1.2").c_str());
 203                 printf("%s %s\n", "192.168.10.1", Cloak4("192.168.10.1").c_str());
 204                 printf("%s %s\n", "192.168.10.1", Cloak4("192.168.10.2").c_str());
 205                 printf("%s %s\n", "192.169.1.1", Cloak4("192.169.1.1").c_str());
 206                 printf("%s %s\n", "192.169.2.1", Cloak4("192.169.2.1").c_str());
 207                 printf("%s %s\n", "200.168.1.1", Cloak4("200.168.1.1").c_str());
 208                 printf("%s %s\n", "200.168.1.3", Cloak4("200.168.1.3").c_str());
 209                 printf("%s %s\n", "200.168.3.3", Cloak4("200.168.3.3").c_str());
 210                 printf("%s %s\n", "200.169.4.3", Cloak4("200.169.4.3").c_str());
 211                 printf("---\n");
 212                 printf("%s %s\n", "9a05:2f00:3f11::5f12::1", Cloak6("9a05:2f00:3f11::5f12::1").c_str());
 213                 printf("%s %s\n", "9a05:2f00:3f11::5f12::2", Cloak6("9a05:2f00:3f11::5f12::2").c_str());
 214                 printf("%s %s\n", "9a05:2f00:3f11::5a12::1", Cloak6("9a05:2f00:3f11::5a12::1").c_str());
 215                 printf("%s %s\n", "9a05:2f00:3f11::5a12::2", Cloak6("9a05:2f00:3f11::5a12::2").c_str());
 216                 printf("%s %s\n", "9a05:3f01:3f11::5f12::1", Cloak6("9a05:3f01:3f11::5f12::1").c_str());
 217                 printf("%s %s\n", "9a05:4f00:3f11::5f13::2", Cloak6("9a05:4f00:3f11::5f13::2").c_str());
 218                 printf("%s %s\n", "ffff:2f00:3f11::5f12::1", Cloak6("ffff:2f00:3f11::5f12::1").c_str());
 219                 printf("%s %s\n", "ffff:2f00:3f11::5f13::2", Cloak6("ffff:2f00:3f11::5f13::2").c_str());
 220                 exit(0);
 221         }
 222         */
 223
 224         void DoRehash()
 225         {
 226                 ConfigReader Conf(ServerInstance);
 227                 key1 = key2 = key3 = key4 = 0;
 228                 key1 = Conf.ReadInteger("cloak","key1",0,false);
 229                 key2 = Conf.ReadInteger("cloak","key2",0,false);
 230                 key3 = Conf.ReadInteger("cloak","key3",0,false);
 231                 key4 = Conf.ReadInteger("cloak","key4",0,false);
 232
 233                 prefix = Conf.ReadValue("cloak","prefix",0);
 234                 if (prefix == "")
 235                 {
 236                         prefix = ServerInstance->Config->Network;
 237                 }
 238                 if (!key1 && !key2 && !key3 && !key4)
 239                 {
 240                         ModuleException ex("You have not defined cloak keys for m_cloaking!!! THIS IS INSECURE AND SHOULD BE CHECKED!");
 241                         throw (ex);
 242                 }
 243         }
 244 };
 245
 246
 247 class ModuleCloaking : public Module
 248 {
 249  private:
 250
 251         CloakUser* cu;
 252         Module* MD5Module;
 253
 254  public:
 255         ModuleCloaking(InspIRCd* Me)
 256                 : Module::Module(Me)
 257         {
 258                 MD5Module = ServerInstance->FindModule("m_md5.so");
 259                 if (!MD5Module)
 260                         throw ModuleException("Can't find m_md5.so. Please load m_md5.so before m_cloaking.so.");
 261
 262                 /* Create new mode handler object */
 263                 cu = new CloakUser(ServerInstance, this, MD5Module);
 264
 265                 /* Register it with the core */
 266                 ServerInstance->AddMode(cu, 'x');
 267
 268                 OnRehash("");
 269         }
 270
 271         virtual ~ModuleCloaking()
 272         {
 273                 ServerInstance->Modes->DelMode(cu);
 274                 DELETE(cu);
 275         }
 276
 277         virtual Version GetVersion()
 278         {
 279                 // returns the version number of the module to be
 280                 // listed in /MODULES
 281                 return Version(1,1,0,2,VF_COMMON|VF_VENDOR,API_VERSION);
 282         }
 283
 284         virtual void OnRehash(const std::string &parameter)
 285         {
 286                 cu->DoRehash();
 287         }
 288
 289         void Implements(char* List)
 290         {
 291                 List[I_OnRehash] = 1;
 292         }
 293 };
 294
 295 // stuff down here is the module-factory stuff. For basic modules you can ignore this.
 296
 297 class ModuleCloakingFactory : public ModuleFactory
 298 {
 299  public:
 300         ModuleCloakingFactory()
 301         {
 302         }
 303
 304         ~ModuleCloakingFactory()
 305         {
 306         }
 307
 308         virtual Module * CreateModule(InspIRCd* Me)
 309         {
 310                 return new ModuleCloaking(Me);
 311         }
 312
 313 };
 314
 315
 316 extern "C" void * init_module( void )
 317 {
 318         return new ModuleCloakingFactory;
 319 }