/* +------------------------------------+ * | Inspire Internet Relay Chat Daemon | * +------------------------------------+ * * InspIRCd: (C) 2002-2009 InspIRCd Development Team * See: http://wiki.inspircd.org/Credits * * This program is free but copyrighted software; see * the file COPYING for details. * * --------------------------------------------------- */ #include "inspircd.h" #include "m_hash.h" /* $ModDesc: Provides masking of user hostnames */ /* $ModDep: m_hash.h */ /** Handles user mode +x */ class CloakUser : public ModeHandler { public: std::string prefix; unsigned int key1; unsigned int key2; unsigned int key3; unsigned int key4; bool ipalways; Module* HashProvider; const char *xtab[4]; LocalStringExt ext; /** 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) { int dots = 0; std::string::size_type splitdot = host.length(); for (std::string::size_type x = host.length() - 1; x; --x) { if (host[x] == '.') { splitdot = x; dots++; } if (dots >= 3) break; } if (splitdot == host.length()) return host; else return host.substr(splitdot); } CloakUser(Module* source, Module* Hash) : ModeHandler(source, 'x', PARAM_NONE, MODETYPE_USER), HashProvider(Hash), ext("cloaked_host", source) { } ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string ¶meter, bool adding) { /* For remote clients, we dont take any action, we just allow it. * The local server where they are will set their cloak instead. * This is fine, as we will recieve it later. */ if (!IS_LOCAL(dest)) { dest->SetMode('x',adding); 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. */ std::string* cloak = ext.get(dest); if (!cloak) { /* Force creation of missing cloak */ creator->OnUserConnect(dest); cloak = ext.get(dest); } if (cloak) { dest->ChangeDisplayedHost(cloak->c_str()); dest->SetMode('x',true); return MODEACTION_ALLOW; } } } 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.c_str()); 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++) { 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(creator, HashProvider).Send(); HashKeyRequest(creator, 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(creator, HashProvider, xtab[(iv[k]+i[k]) % 4]).Send(); ra[k] = std::string(HashSumRequest(creator, 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]); } std::string Cloak6(const char* ip) { unsigned int iv[] = { key1, key2, key3, key4 }; std::vector hashies; std::string item; int rounds = 0; /* Reset the Hash module and send it our IV */ HashResetRequest(creator, HashProvider).Send(); HashKeyRequest(creator, 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(creator, HashProvider, xtab[(key1+rounds) % 4]).Send(); hashies.push_back(std::string(HashSumRequest(creator, 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(creator, HashProvider, xtab[(key1+rounds) % 4]).Send(); hashies.push_back(std::string(HashSumRequest(creator, 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 = " is not valid, it may be set to a too high/low value, or it may not exist."; else if (!key2) detail = " is not valid, it may be set to a too high/low value, or it may not exist."; else if (!key3) detail = " is not valid, it may be set to a too high/low value, or it may not exist."; else if (!key4) detail = " 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); } } }; class ModuleCloaking : public Module { private: CloakUser* cu; public: ModuleCloaking(InspIRCd*) { /* Attempt to locate the md5 service provider, bail if we can't find it */ Module* 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(this, HashModule); try { OnRehash(NULL); } catch (ModuleException &e) { delete cu; throw e; } /* Register it with the core */ if (!ServerInstance->Modes->AddMode(cu)) { delete cu; throw ModuleException("Could not add new modes!"); } ServerInstance->Modules->UseInterface("HashRequest"); Extensible::Register(&cu->ext); Implementation eventlist[] = { I_OnRehash, I_OnCheckBan, I_OnUserConnect }; ServerInstance->Modules->Attach(eventlist, this, 3); CloakExistingUsers(); } void CloakExistingUsers() { std::string* cloak; for (std::vector::iterator u = ServerInstance->Users->local_users.begin(); u != ServerInstance->Users->local_users.end(); u++) { cloak = cu->ext.get(*u); if (!cloak) { OnUserConnect(*u); } } } ModResult OnCheckBan(User* user, Channel* chan, const std::string& mask) { char cmask[MAXBUF]; std::string* cloak = cu->ext.get(user); /* Check if they have a cloaked host, but are not using it */ if (cloak && *cloak != user->dhost) { snprintf(cmask, MAXBUF, "%s!%s@%s", user->nick.c_str(), user->ident.c_str(), cloak->c_str()); if (InspIRCd::Match(cmask,mask)) return MOD_RES_DENY; } return MOD_RES_PASSTHRU; } void Prioritize() { /* Needs to be after m_banexception etc. */ ServerInstance->Modules->SetPriority(this, I_OnCheckBan, PRIORITY_LAST); /* but before m_conn_umodes, so host is generated ready to apply */ Module *um = ServerInstance->Modules->Find("m_conn_umodes.so"); ServerInstance->Modules->SetPriority(this, I_OnUserConnect, PRIORITY_AFTER, &um); } ~ModuleCloaking() { ServerInstance->Modes->DelMode(cu); delete cu; ServerInstance->Modules->DoneWithInterface("HashRequest"); } Version GetVersion() { // returns the version number of the module to be // listed in /MODULES return Version("Provides masking of user hostnames", VF_COMMON|VF_VENDOR,API_VERSION); } void OnRehash(User* user) { cu->DoRehash(); } void OnUserConnect(User* dest) { std::string* cloak = cu->ext.get(dest); if (cloak) return; if (dest->host.find('.') != std::string::npos || dest->host.find(':') != std::string::npos) { unsigned int iv[] = { cu->key1, cu->key2, cu->key3, cu->key4 }; std::string a = cu->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 which always cloaks * the IP, for anonymity. --nenolod */ if (!cu->ipalways) { /** Reset the Hash module, and send it our IV and hex table */ HashResetRequest(this, cu->HashProvider).Send(); HashKeyRequest(this, cu->HashProvider, iv).Send(); HashHexRequest(this, cu->HashProvider, cu->xtab[(dest->host[0]) % 4]); /* Generate a cloak using specialized Hash */ std::string hostcloak = cu->prefix + "-" + std::string(HashSumRequest(this, cu->HashProvider, dest->host.c_str()).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. */ std::string testaddr; int testport; if (!irc::sockets::satoap(&dest->client_sa, testaddr, testport) && (hostcloak.length() <= 64)) /* not a valid address, must have been a host, so cloak as a host */ b = hostcloak; else if (dest->client_sa.sa.sa_family == AF_INET6) b = cu->Cloak6(dest->GetIPString()); else b = cu->Cloak4(dest->GetIPString()); } else { if (dest->client_sa.sa.sa_family == AF_INET6) b = cu->Cloak6(dest->GetIPString()); else b = cu->Cloak4(dest->GetIPString()); } cu->ext.set(dest,b); } } }; MODULE_INIT(ModuleCloaking)