]> git.netwichtig.de Git - user/henk/code/inspircd.git/blobdiff - src/modules/m_cloaking.cpp
Header update: 2007 -> 2008
[user/henk/code/inspircd.git] / src / modules / m_cloaking.cpp
index 5fa77067b910ab0f97a6f367760ce5d3e81f25b0..d9f5be30212b861c8200416937b933a9a1839323 100644 (file)
  *       | Inspire Internet Relay Chat Daemon |
  *       +------------------------------------+
  *
- *  Inspire is copyright (C) 2002-2004 ChatSpike-Dev.
- *                       E-mail:
- *                <brain@chatspike.net>
- *               <Craig@chatspike.net>
- *     
- * Written by Craig Edwards, Craig McLure, and others.
+ *  InspIRCd: (C) 2002-2008 InspIRCd Development Team
+ * See: http://www.inspircd.org/wiki/index.php/Credits
+ *
  * This program is free but copyrighted software; see
  *            the file COPYING for details.
  *
  * ---------------------------------------------------
  */
 
-// Hostname cloaking (+x mode) module for inspircd.
-// version 1.0.0.1 by brain (C. J. Edwards) Mar 2004.
-//
-// When loaded this module will automatically set the
-// +x mode on all connecting clients.
-//
-// Setting +x on a client causes the module to change the
-// dhost entry (displayed host) for each user who has the
-// mode, cloaking their host. Unlike unreal, the algorithm
-// is non-reversible as uncloaked hosts are passed along
-// the server->server link, and all encoding of hosts is
-// done locally on the server by this module.
-
-#include <stdio.h>
-#include "users.h"
-#include "channels.h"
-#include "modules.h"
+#include "inspircd.h"
+#include "m_hash.h"
 
 /* $ModDesc: Provides masking of user hostnames */
+/* $ModDep: m_hash.h */
 
-class ModuleCloaking : public Module
+/** Handles user mode +x
+ */
+class CloakUser : public ModeHandler
 {
- private:
+       std::string prefix;
+       unsigned int key1;
+       unsigned int key2;
+       unsigned int key3;
+       unsigned int key4;
+       bool ipalways;
+       Module* Sender;
+       Module* HashProvider;
+       const char *xtab[4];
 
-        Server *Srv;
-        
- public:
-       ModuleCloaking()
+       /** This function takes a domain name string and returns just the last two domain parts,
+        * or the last domain part if only two are available. Failing that it just returns what it was given.
+        *
+        * For example, if it is passed "svn.inspircd.org" it will return ".inspircd.org".
+        * If it is passed "brainbox.winbot.co.uk" it will return ".co.uk",
+        * and if it is passed "localhost.localdomain" it will return ".localdomain".
+        * 
+        * This is used to ensure a significant part of the host is always cloaked (see Bug #216)
+        */
+       std::string LastTwoDomainParts(const std::string &host)
        {
-               // We must create an instance of the Server class to work with
-               Srv = new Server;
-               
-               // we must create a new mode. Set the parameters so the
-               // mode doesn't require oper, and is a client usermode
-               // with no parameters (actually, you cant have params for a umode!)
-               if (!Srv->AddExtendedMode('x',MT_CLIENT,false,0,0))
+               int dots = 0;
+               std::string::size_type splitdot = host.length();
+
+               for (std::string::size_type x = host.length() - 1; x; --x)
                {
-                       // we couldn't claim mode x... possibly anther module has it,
-                       // this might become likely to happen if there are a lot of 3rd
-                       // party modules around in the future -- any 3rd party modules
-                       // SHOULD implement a system of configurable mode letters (e.g.
-                       // from a config file)
-                       Srv->Log(DEFAULT,"*** m_cloaking: ERROR, failed to allocate user mode +x!");
-                       printf("Could not claim usermode +x for this module!");
-                       exit(0);
+                       if (host[x] == '.')
+                       {
+                               splitdot = x;
+                               dots++;
+                       }
+                       if (dots >= 3)
+                               break;
                }
+
+               if (splitdot == host.length())
+                       return host;
+               else
+                       return host.substr(splitdot);
        }
        
-       virtual ~ModuleCloaking()
-       {
-               // not really neccessary, but free it anyway
-               delete Srv;
-       }
-       
-       virtual Version GetVersion()
+ public:
+       CloakUser(InspIRCd* Instance, Module* Source, Module* Hash) : ModeHandler(Instance, 'x', 0, 0, false, MODETYPE_USER, false), Sender(Source), HashProvider(Hash)
        {
-               // returns the version number of the module to be
-               // listed in /MODULES
-               return Version(1,0,0,1,VF_STATIC|VF_VENDOR);
        }
-       
-       virtual int OnExtendedMode(userrec* user, void* target, char modechar, int type, bool mode_on, string_list &params)
+
+       ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding)
        {
-               // this method is called for any extended mode character.
-               // all module modes for all modules pass through here
-               // (unless another module further up the chain claims them)
-               // so we must be VERY careful to only act upon modes which
-               // we have claimed ourselves. This is a feature to allow
-               // modules to 'spy' on extended mode activity if they so wish.
-               if ((modechar == 'x') && (type == MT_CLIENT))
-               {
-                       // OnExtendedMode gives us a void* as the target, we must cast
-                       // it into a userrec* or a chanrec* depending on the value of
-                       // the 'type' parameter (MT_CLIENT or MT_CHANNEL)
-                       userrec* dest = (userrec*)target;
-                       
-                       // we've now determined that this is our mode character...
-                       // is the user adding the mode to their list or removing it?
-                       if (mode_on)
+               if (source != dest)
+                       return MODEACTION_DENY;
+
+               /* For remote clients, we dont take any action, we just allow it.
+                * The local server where they are will set their cloak instead.
+                */
+               if (!IS_LOCAL(dest))
+                       return MODEACTION_ALLOW;
+
+               /* don't allow this user to spam modechanges */
+               dest->IncreasePenalty(5);
+
+               if (adding)
+               {
+                       if(!dest->IsModeSet('x'))
                        {
-                               // the mode is being turned on - so attempt to
-                               // allocate the user a cloaked host using a non-reversible
-                               // algorithm (its simple, but its non-reversible so the
-                               // simplicity doesnt really matter). This algorithm
-                               // will not work if the user has only one level of domain
-                               // naming in their hostname (e.g. if they are on a lan or
-                               // are connecting via localhost) -- this doesnt matter much.
-                               if (strchr(dest->host,'.'))
+                               /* The mode is being turned on - so attempt to
+                                * allocate the user a cloaked host using a non-reversible
+                                * algorithm (its simple, but its non-reversible so the
+                                * simplicity doesnt really matter). This algorithm
+                                * will not work if the user has only one level of domain
+                                * naming in their hostname (e.g. if they are on a lan or
+                                * are connecting via localhost) -- this doesnt matter much.
+                                */
+
+                               char* n1 = strchr(dest->host,'.');
+                               char* n2 = strchr(dest->host,':');
+                       
+                               if (n1 || n2)
                                {
-                                       // in inspircd users have two hostnames. A displayed
-                                       // hostname which can be modified by modules (e.g.
-                                       // to create vhosts, implement chghost, etc) and a
-                                       // 'real' hostname which you shouldnt write to.
-                                       std::string a = strstr(dest->host,".");
-                                       char ra[64];
-                                       long seed,s2;
-                                       memcpy(&seed,dest->host,sizeof(long));
-                                       memcpy(&s2,a.c_str(),sizeof(long));
-                                       sprintf(ra,"%.8X",seed*s2*strlen(dest->host));
-                                       std::string b = Srv->GetNetworkName() + "-" + ra + a;
-                                       Srv->Log(DEBUG,"cloak: allocated "+b);
-                                       Srv->ChangeHost(dest,b);
+                                       unsigned int iv[] = { key1, key2, key3, key4 };
+                                       std::string a = LastTwoDomainParts(dest->host);
+                                       std::string b;
+
+                                       /* InspIRCd users have two hostnames; A displayed
+                                        * hostname which can be modified by modules (e.g.
+                                        * to create vhosts, implement chghost, etc) and a
+                                        * 'real' hostname which you shouldnt write to.
+                                        */
+
+                                       /* 2008/08/18: add <cloak:ipalways> which always cloaks
+                                        * the IP, for anonymity. --nenolod
+                                        */
+                                       if (!ipalways)
+                                       {
+                                               /** Reset the Hash module, and send it our IV and hex table */
+                                               HashResetRequest(Sender, HashProvider).Send();
+                                               HashKeyRequest(Sender, HashProvider, iv).Send();
+                                               HashHexRequest(Sender, HashProvider, xtab[(*dest->host) % 4]);
+
+                                               /* Generate a cloak using specialized Hash */
+                                               std::string hostcloak = prefix + "-" + std::string(HashSumRequest(Sender, HashProvider, dest->host).Send()).substr(0,8) + a;
+
+                                               /* Fix by brain - if the cloaked host is > the max length of a host (64 bytes
+                                                * according to the DNS RFC) then tough titty, they get cloaked as an IP. 
+                                                * Their ISP shouldnt go to town on subdomains, or they shouldnt have a kiddie
+                                                * vhost.
+                                                */
+#ifdef IPV6
+                                               in6_addr testaddr;
+                                               in_addr testaddr2;
+                                               if ((dest->GetProtocolFamily() == AF_INET6) && (inet_pton(AF_INET6,dest->host,&testaddr) < 1) && (hostcloak.length() <= 64))
+                                                       /* Invalid ipv6 address, and ipv6 user (resolved host) */
+                                                       b = hostcloak;
+                                               else if ((dest->GetProtocolFamily() == AF_INET) && (inet_aton(dest->host,&testaddr2) < 1) && (hostcloak.length() <= 64))
+                                                       /* Invalid ipv4 address, and ipv4 user (resolved host) */
+                                                       b = hostcloak;
+                                               else
+                                                       /* Valid ipv6 or ipv4 address (not resolved) ipv4 or ipv6 user */
+                                                       b = ((!strchr(dest->host,':')) ? Cloak4(dest->host) : Cloak6(dest->host));
+#else
+                                               in_addr testaddr;
+                                               if ((inet_aton(dest->host,&testaddr) < 1) && (hostcloak.length() <= 64))
+                                                       /* Invalid ipv4 address, and ipv4 user (resolved host) */
+                                                       b = hostcloak;
+                                               else
+                                                       /* Valid ipv4 address (not resolved) ipv4 user */
+                                                       b = Cloak4(dest->host);
+#endif
+                                       }
+                                       else
+                                       {
+#ifdef IPV6
+                                               if (dest->GetProtocolFamily() == AF_INET6)
+                                                       b = Cloak6(dest->GetIPString());
+#endif
+                                               if (dest->GetProtocolFamily() == AF_INET)
+                                                       b = Cloak4(dest->GetIPString());
+                                       }
+
+                                       dest->ChangeDisplayedHost(b.c_str());
                                }
+                               
+                               dest->SetMode('x',true);
+                               return MODEACTION_ALLOW;
                        }
-                       else
-                       {
-                               // user is removing the mode, so just restore their real host
-                               // and make it match the displayed one.
-                               Srv->ChangeHost(dest,dest->host);
-                       }
-                       // this mode IS ours, and we have handled it. If we chose not to handle it,
-                       // for example the user cannot cloak as they have a vhost or such, then
-                       // we could return 0 here instead of 1 and the core would not send the mode
-                       // change to the user.
-                       return 1;
                }
                else
+               {
+                       if (dest->IsModeSet('x'))
+                       {
+                               /* User is removing the mode, so just restore their real host
+                                * and make it match the displayed one.
+                                */
+                               dest->ChangeDisplayedHost(dest->host);
+                               dest->SetMode('x',false);
+                               return MODEACTION_ALLOW;
+                       }
+               }
+
+               return MODEACTION_DENY;
+       }
+
+       std::string Cloak4(const char* ip)
+       {
+               unsigned int iv[] = { key1, key2, key3, key4 };
+               irc::sepstream seps(ip, '.');
+               std::string ra[4];;
+               std::string octet[4];
+               int i[4];
+
+               for (int j = 0; j < 4; j++)
                {
-                       // this mode isn't ours, we have to bail and return 0 to not handle it.
-                       return 0;
+                       seps.GetToken(octet[j]);
+                       i[j] = atoi(octet[j].c_str());
                }
+
+               octet[3] = octet[0] + "." + octet[1] + "." + octet[2] + "." + octet[3];
+               octet[2] = octet[0] + "." + octet[1] + "." + octet[2];
+               octet[1] = octet[0] + "." + octet[1];
+
+               /* Reset the Hash module and send it our IV */
+               HashResetRequest(Sender, HashProvider).Send();
+               HashKeyRequest(Sender, HashProvider, iv).Send();
+
+               /* Send the Hash module a different hex table for each octet group's Hash sum */
+               for (int k = 0; k < 4; k++)
+               {
+                       HashHexRequest(Sender, HashProvider, xtab[(iv[k]+i[k]) % 4]).Send();
+                       ra[k] = std::string(HashSumRequest(Sender, HashProvider, octet[k]).Send()).substr(0,6);
+               }
+               /* Stick them all together */
+               return std::string().append(ra[0]).append(".").append(ra[1]).append(".").append(ra[2]).append(".").append(ra[3]);
        }
 
-       virtual void OnUserConnect(userrec* user)
+       std::string Cloak6(const char* ip)
        {
-               // Heres the weird bit. When a user connects we must set +x on them, so
-               // we're going to use the SendMode method of the Server class to send
-               // the mode to the client. This is basically the same as sending an
-               // SAMODE in unreal. Note that to the user it will appear as if they set
-               // the mode on themselves.
-               
-               char* modes[2];                 // only two parameters
-               modes[0] = user->nick;          // first parameter is the nick
-               modes[1] = "+x";                // second parameter is the mode
-               Srv->SendMode(modes,2,user);    // send these, forming the command "MODE <nick> +x"
+               /* Theyre using 4in6 (YUCK). Translate as ipv4 cloak */
+               if (!strncmp(ip, "0::ffff:", 8))
+                       return Cloak4(ip + 8);
+
+               /* If we get here, yes it really is an ipv6 ip */
+               unsigned int iv[] = { key1, key2, key3, key4 };
+               std::vector<std::string> hashies;
+               std::string item;
+               int rounds = 0;
+
+               /* Reset the Hash module and send it our IV */
+               HashResetRequest(Sender, HashProvider).Send();
+               HashKeyRequest(Sender, HashProvider, iv).Send();
+
+               for (const char* input = ip; *input; input++)
+               {
+                       item += *input;
+                       if (item.length() > 7)
+                       {
+                               /* Send the Hash module a different hex table for each octet group's Hash sum */
+                               HashHexRequest(Sender, HashProvider, xtab[(key1+rounds) % 4]).Send();
+                               hashies.push_back(std::string(HashSumRequest(Sender, HashProvider, item).Send()).substr(0,8));
+                               item.clear();
+                       }
+                       rounds++;
+               }
+               if (!item.empty())
+               {
+                       /* Send the Hash module a different hex table for each octet group's Hash sum */
+                       HashHexRequest(Sender, HashProvider, xtab[(key1+rounds) % 4]).Send();
+                       hashies.push_back(std::string(HashSumRequest(Sender, HashProvider, item).Send()).substr(0,8));
+                       item.clear();
+               }
+               /* Stick them all together */
+               return irc::stringjoiner(":", hashies, 0, hashies.size() - 1).GetJoined();
        }
+       
+       void DoRehash()
+       {
+               ConfigReader Conf(ServerInstance);
+               bool lowercase;
+               
+               /* These are *not* using the need_positive parameter of ReadInteger - 
+                * that will limit the valid values to only the positive values in a
+                * signed int. Instead, accept any value that fits into an int and
+                * cast it to an unsigned int. That will, a bit oddly, give us the full
+                * spectrum of an unsigned integer. - Special */
+               key1 = key2 = key3 = key4 = 0;
+               key1 = (unsigned int) Conf.ReadInteger("cloak","key1",0,false);
+               key2 = (unsigned int) Conf.ReadInteger("cloak","key2",0,false);
+               key3 = (unsigned int) Conf.ReadInteger("cloak","key3",0,false);
+               key4 = (unsigned int) Conf.ReadInteger("cloak","key4",0,false);
+               prefix = Conf.ReadValue("cloak","prefix",0);
+               ipalways = Conf.ReadFlag("cloak", "ipalways", 0);
+               lowercase = Conf.ReadFlag("cloak", "lowercase", 0);
+               
+               if (!lowercase)
+               {
+                       xtab[0] = "F92E45D871BCA630";
+                       xtab[1] = "A1B9D80C72E653F4";
+                       xtab[2] = "1ABC078934DEF562";
+                       xtab[3] = "ABCDEF5678901234";
+               }
+               else
+               {
+                       xtab[0] = "f92e45d871bca630";
+                       xtab[1] = "a1b9d80c72e653f4";
+                       xtab[2] = "1abc078934def562";
+                       xtab[3] = "abcdef5678901234";
+               }
 
+               if (prefix.empty())
+                       prefix = ServerInstance->Config->Network;
+
+               if (!key1 || !key2 || !key3 || !key4)
+               {
+                       std::string detail;
+                       if (!key1)
+                               detail = "<cloak:key1> is not valid, it may be set to a too high/low value, or it may not exist.";
+                       else if (!key2)
+                               detail = "<cloak:key2> is not valid, it may be set to a too high/low value, or it may not exist.";
+                       else if (!key3)
+                               detail = "<cloak:key3> is not valid, it may be set to a too high/low value, or it may not exist.";
+                       else if (!key4)
+                               detail = "<cloak:key4> is not valid, it may be set to a too high/low value, or it may not exist.";
+
+                       throw ModuleException("You have not defined cloak keys for m_cloaking!!! THIS IS INSECURE AND SHOULD BE CHECKED! - " + detail);
+               }
+       }
 };
 
-// stuff down here is the module-factory stuff. For basic modules you can ignore this.
 
-class ModuleCloakingFactory : public ModuleFactory
+class ModuleCloaking : public Module
 {
+ private:
+       
+       CloakUser* cu;
+       Module* HashModule;
+
  public:
-       ModuleCloakingFactory()
+       ModuleCloaking(InspIRCd* Me)
+               : Module(Me)
        {
+               /* Attempt to locate the md5 service provider, bail if we can't find it */
+               HashModule = ServerInstance->Modules->Find("m_md5.so");
+               if (!HashModule)
+                       throw ModuleException("Can't find m_md5.so. Please load m_md5.so before m_cloaking.so.");
+
+               cu = new CloakUser(ServerInstance, this, HashModule);
+
+               try
+               {
+                       OnRehash(NULL,"");
+               }
+               catch (CoreException &e)
+               {
+                       delete cu;
+                       throw e;
+               }
+
+               /* Register it with the core */
+               if (!ServerInstance->AddMode(cu))
+               {
+                       delete cu;
+                       throw ModuleException("Could not add new modes!");
+               }
+
+               ServerInstance->Modules->UseInterface("HashRequest");
+
+               Implementation eventlist[] = { I_OnRehash };
+               ServerInstance->Modules->Attach(eventlist, this, 1);
        }
        
-       ~ModuleCloakingFactory()
+       virtual ~ModuleCloaking()
        {
+               ServerInstance->Modes->DelMode(cu);
+               delete cu;
+               ServerInstance->Modules->DoneWithInterface("HashRequest");
        }
        
-       virtual Module * CreateModule()
+       virtual Version GetVersion()
        {
-               return new ModuleCloaking;
+               // returns the version number of the module to be
+               // listed in /MODULES
+               return Version(1,1,0,2,VF_COMMON|VF_VENDOR,API_VERSION);
        }
-       
-};
 
+       virtual void OnRehash(User* user, const std::string &parameter)
+       {
+               cu->DoRehash();
+       }
 
-extern "C" void * init_module( void )
-{
-       return new ModuleCloakingFactory;
-}
+};
 
+MODULE_INIT(ModuleCloaking)