X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fmodules%2Fm_cloaking.cpp;h=105d688337d20d0afb767059815bf10ace8c5671;hb=aec9540601a8ca8632d0a4e0c4cec1484cfef99a;hp=8fd4e43e58d36e5a21c44cde706efa98a8ef26f5;hpb=1e1e59d32934ee61562804cd86321ffe849c1ecb;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/src/modules/m_cloaking.cpp b/src/modules/m_cloaking.cpp index 8fd4e43e5..105d68833 100644 --- a/src/modules/m_cloaking.cpp +++ b/src/modules/m_cloaking.cpp @@ -1,165 +1,562 @@ -// 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 -#include "users.h" -#include "channels.h" -#include "modules.h" +/* + * InspIRCd -- Internet Relay Chat Daemon + * + * Copyright (C) 2009-2010 Daniel De Graaf + * Copyright (C) 2006-2008 Robin Burchell + * Copyright (C) 2008 Pippijn van Steenhoven + * Copyright (C) 2003-2008 Craig Edwards + * Copyright (C) 2007 John Brooks + * Copyright (C) 2007 Dennis Friis + * Copyright (C) 2006 Oliver Lupton + * + * This file is part of InspIRCd. InspIRCd is free software: you can + * redistribute it and/or modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#include "inspircd.h" +#include "hash.h" /* $ModDesc: Provides masking of user hostnames */ -class ModuleCloaking : public Module +enum CloakMode { - private: + /** 1.2-compatible host-based cloak */ + MODE_COMPAT_HOST, + /** 1.2-compatible IP-only cloak */ + MODE_COMPAT_IPONLY, + /** 2.0 cloak of "half" of the hostname plus the full IP hash */ + MODE_HALF_CLOAK, + /** 2.0 cloak of IP hash, split at 2 common CIDR range points */ + MODE_OPAQUE +}; + +// lowercase-only encoding similar to base64, used for hash output +static const char base32[] = "0123456789abcdefghijklmnopqrstuv"; - Server *Srv; - +/** Handles user mode +x + */ +class CloakUser : public ModeHandler +{ public: - ModuleCloaking() - { - // 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)) - { - // 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); - } - } - - virtual ~ModuleCloaking() - { - // not really neccessary, but free it anyway - delete Srv; - } - - virtual Version GetVersion() - { - // returns the version number of the module to be - // listed in /MODULES - return Version(1,0,0,1); - } - - virtual bool OnExtendedMode(userrec* user, void* target, char modechar, int type, bool mode_on, string_list ¶ms) - { - // 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) + LocalStringExt ext; + + std::string debounce_uid; + time_t debounce_ts; + int debounce_count; + + CloakUser(Module* source) + : ModeHandler(source, "cloak", 'x', PARAM_NONE, MODETYPE_USER), + ext("cloaked_host", source), debounce_ts(0), debounce_count(0) + { + } + + ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string ¶meter, bool adding) + { + LocalUser* user = IS_LOCAL(dest); + + /* For remote clients, we don't take any action, we just allow it. + * The local server where they are will set their cloak instead. + * This is fine, as we will receive it later. + */ + if (!user) + { + dest->SetMode('x',adding); + return MODEACTION_ALLOW; + } + + if (user->uuid == debounce_uid && debounce_ts == ServerInstance->Time()) + { + // prevent spamming using /mode user +x-x+x-x+x-x + if (++debounce_count > 2) + return MODEACTION_DENY; + } + else + { + debounce_uid = user->uuid; + debounce_count = 1; + debounce_ts = ServerInstance->Time(); + } + + if (adding == user->IsModeSet('x')) + return MODEACTION_DENY; + + /* don't allow this user to spam modechanges */ + if (source == dest) + user->CommandFloodPenalty += 5000; + + if (adding) + { + std::string* cloak = ext.get(user); + + if (!cloak) { - // 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 (strstr(dest->host,".")) - { - // 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); - strcpy(dest->dhost,b.c_str()); - } + /* Force creation of missing cloak */ + creator->OnUserConnect(user); + cloak = ext.get(user); } - else - { - // user is removing the mode, so just restore their real host - // and make it match the displayed one. - strcpy(dest->dhost,dest->host); + if (cloak) + { + user->ChangeDisplayedHost(cloak->c_str()); + user->SetMode('x',true); + return MODEACTION_ALLOW; } - // 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 + return MODEACTION_DENY; } else { - // this mode isn't ours, we have to bail and return 0 to not handle it. - return 0; + /* User is removing the mode, so restore their real host + * and make it match the displayed one. + */ + user->SetMode('x',false); + user->ChangeDisplayedHost(user->host.c_str()); + return MODEACTION_ALLOW; } } - virtual void OnUserConnect(userrec* user) +}; + +class CommandCloak : public Command +{ + public: + CommandCloak(Module* Creator) : Command(Creator, "CLOAK", 1) { - // 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 +x" + flags_needed = 'o'; + syntax = ""; } + CmdResult Handle(const std::vector ¶meters, User *user); }; -// stuff down here is the module-factory stuff. For basic modules you can ignore this. - -class ModuleCloakingFactory : public ModuleFactory +class ModuleCloaking : public Module { public: - ModuleCloakingFactory() + CloakUser cu; + CloakMode mode; + CommandCloak ck; + std::string prefix; + std::string suffix; + std::string key; + unsigned int compatkey[4]; + const char* xtab[4]; + dynamic_reference Hash; + + ModuleCloaking() : cu(this), mode(MODE_OPAQUE), ck(this), Hash(this, "hash/md5") { } - - ~ModuleCloakingFactory() + + void init() { + OnRehash(NULL); + + ServerInstance->Modules->AddService(cu); + ServerInstance->Modules->AddService(ck); + ServerInstance->Modules->AddService(cu.ext); + + Implementation eventlist[] = { I_OnRehash, I_OnCheckBan, I_OnUserConnect, I_OnChangeHost }; + ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation)); } - - virtual Module * CreateModule() + + /** 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) { - return new ModuleCloaking; + 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 ""; + else + return host.substr(splitdot); } - -}; + /** + * 2.0-style cloaking function + * @param item The item to cloak (part of an IP or hostname) + * @param id A unique ID for this type of item (to make it unique if the item matches) + * @param len The length of the output. Maximum for MD5 is 16 characters. + */ + std::string SegmentCloak(const std::string& item, char id, int len) + { + std::string input; + input.reserve(key.length() + 3 + item.length()); + input.append(1, id); + input.append(key); + input.append(1, '\0'); // null does not terminate a C++ string + input.append(item); + + std::string rv = Hash->sum(input).substr(0,len); + for(int i=0; i < len; i++) + { + // this discards 3 bits per byte. We have an + // overabundance of bits in the hash output, doesn't + // matter which ones we are discarding. + rv[i] = base32[rv[i] & 0x1F]; + } + return rv; + } + + std::string CompatCloak4(const char* ip) + { + irc::sepstream seps(ip, '.'); + 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 */ + + std::string rv; + + /* Send the Hash module a different hex table for each octet group's Hash sum */ + for (int k = 0; k < 4; k++) + { + rv.append(Hash->sumIV(compatkey, xtab[(compatkey[k]+i[k]) % 4], octet[k]).substr(0,6)); + if (k < 3) + rv.append("."); + } + /* Stick them all together */ + return rv; + } + + std::string CompatCloak6(const char* ip) + { + std::vector hashies; + std::string item; + int rounds = 0; + + /* Reset the Hash module and send it our IV */ + + for (const char* input = ip; *input; input++) + { + item += *input; + if (item.length() > 7) + { + hashies.push_back(Hash->sumIV(compatkey, xtab[(compatkey[0]+rounds) % 4], item).substr(0,8)); + item.clear(); + } + rounds++; + } + if (!item.empty()) + { + hashies.push_back(Hash->sumIV(compatkey, xtab[(compatkey[0]+rounds) % 4], item).substr(0,8)); + } + /* Stick them all together */ + return irc::stringjoiner(":", hashies, 0, hashies.size() - 1).GetJoined(); + } + + std::string SegmentIP(const irc::sockets::sockaddrs& ip, bool full) + { + std::string bindata; + int hop1, hop2, hop3; + int len1, len2; + std::string rv; + if (ip.sa.sa_family == AF_INET6) + { + bindata = std::string((const char*)ip.in6.sin6_addr.s6_addr, 16); + hop1 = 8; + hop2 = 6; + hop3 = 4; + len1 = 6; + len2 = 4; + // pfx s1.s2.s3. (xxxx.xxxx or s4) sfx + // 6 4 4 9/6 + rv.reserve(prefix.length() + 26 + suffix.length()); + } + else + { + bindata = std::string((const char*)&ip.in4.sin_addr, 4); + hop1 = 3; + hop2 = 0; + hop3 = 2; + len1 = len2 = 3; + // pfx s1.s2. (xxx.xxx or s3) sfx + rv.reserve(prefix.length() + 15 + suffix.length()); + } -extern "C" void * init_module( void ) + rv.append(prefix); + rv.append(SegmentCloak(bindata, 10, len1)); + rv.append(1, '.'); + bindata.erase(hop1); + rv.append(SegmentCloak(bindata, 11, len2)); + if (hop2) + { + rv.append(1, '.'); + bindata.erase(hop2); + rv.append(SegmentCloak(bindata, 12, len2)); + } + + if (full) + { + rv.append(1, '.'); + bindata.erase(hop3); + rv.append(SegmentCloak(bindata, 13, 6)); + rv.append(suffix); + } + else + { + char buf[50]; + if (ip.sa.sa_family == AF_INET6) + { + snprintf(buf, 50, ".%02x%02x.%02x%02x%s", + ip.in6.sin6_addr.s6_addr[2], ip.in6.sin6_addr.s6_addr[3], + ip.in6.sin6_addr.s6_addr[0], ip.in6.sin6_addr.s6_addr[1], suffix.c_str()); + } + else + { + const unsigned char* ip4 = (const unsigned char*)&ip.in4.sin_addr; + snprintf(buf, 50, ".%d.%d%s", ip4[1], ip4[0], suffix.c_str()); + } + rv.append(buf); + } + return rv; + } + + ModResult OnCheckBan(User* user, Channel* chan, const std::string& mask) + { + LocalUser* lu = IS_LOCAL(user); + if (!lu) + return MOD_RES_PASSTHRU; + + OnUserConnect(lu); + std::string* cloak = cu.ext.get(user); + /* Check if they have a cloaked host, but are not using it */ + if (cloak && *cloak != user->dhost) + { + char cmask[MAXBUF]; + 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); + } + + // this unsets umode +x on every host change. If we are actually doing a +x + // mode change, we will call SetMode back to true AFTER the host change is done. + void OnChangeHost(User* u, const std::string& host) + { + if(u->IsModeSet('x')) + { + u->SetMode('x', false); + u->WriteServ("MODE %s -x", u->nick.c_str()); + } + } + + ~ModuleCloaking() + { + } + + Version GetVersion() + { + std::string testcloak = "broken"; + if (Hash) + { + switch (mode) + { + case MODE_COMPAT_HOST: + testcloak = prefix + "-" + Hash->sumIV(compatkey, xtab[0], "*").substr(0,10); + break; + case MODE_COMPAT_IPONLY: + testcloak = Hash->sumIV(compatkey, xtab[0], "*").substr(0,10); + break; + case MODE_HALF_CLOAK: + testcloak = prefix + SegmentCloak("*", 3, 8) + suffix; + break; + case MODE_OPAQUE: + testcloak = prefix + SegmentCloak("*", 4, 8) + suffix; + } + } + return Version("Provides masking of user hostnames", VF_COMMON|VF_VENDOR, testcloak); + } + + void OnRehash(User* user) + { + ConfigTag* tag = ServerInstance->Config->ConfValue("cloak"); + prefix = tag->getString("prefix"); + suffix = tag->getString("suffix", ".IP"); + + std::string modestr = tag->getString("mode"); + if (modestr == "compat-host") + mode = MODE_COMPAT_HOST; + else if (modestr == "compat-ip") + mode = MODE_COMPAT_IPONLY; + else if (modestr == "half") + mode = MODE_HALF_CLOAK; + else if (modestr == "full") + mode = MODE_OPAQUE; + else + throw ModuleException("Bad value for ; must be one of compat-host, compat-ip, half, full"); + + if (mode == MODE_COMPAT_HOST || mode == MODE_COMPAT_IPONLY) + { + bool lowercase = tag->getBool("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 + * + * We must limit the keys or else we get different results on + * amd64/x86 boxes. - psychon */ + const unsigned int limit = 0x80000000; + compatkey[0] = (unsigned int) tag->getInt("key1"); + compatkey[1] = (unsigned int) tag->getInt("key2"); + compatkey[2] = (unsigned int) tag->getInt("key3"); + compatkey[3] = (unsigned int) tag->getInt("key4"); + + 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 (!compatkey[0] || !compatkey[1] || !compatkey[2] || !compatkey[3] || + compatkey[0] >= limit || compatkey[1] >= limit || compatkey[2] >= limit || compatkey[3] >= limit) + { + std::string detail; + if (!compatkey[0] || compatkey[0] >= limit) + detail = " is not valid, it may be set to a too high/low value, or it may not exist."; + else if (!compatkey[1] || compatkey[1] >= limit) + detail = " is not valid, it may be set to a too high/low value, or it may not exist."; + else if (!compatkey[2] || compatkey[2] >= limit) + detail = " is not valid, it may be set to a too high/low value, or it may not exist."; + else if (!compatkey[3] || compatkey[3] >= limit) + 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); + } + } + else + { + key = tag->getString("key"); + if (key.empty() || key == "secret") + throw ModuleException("You have not defined cloak keys for m_cloaking. Define as a network-wide secret."); + } + } + + std::string GenCloak(const irc::sockets::sockaddrs& ip, const std::string& ipstr, const std::string& host) + { + std::string chost; + + switch (mode) + { + case MODE_COMPAT_HOST: + { + if (ipstr != host) + { + std::string tail = LastTwoDomainParts(host); + + // xtab is not used here due to a bug in 1.2 cloaking + chost = prefix + "-" + Hash->sumIV(compatkey, "0123456789abcdef", host).substr(0,8) + tail; + + /* Fix by brain - if the cloaked host is > the max length of a host (64 bytes + * according to the DNS RFC) then they get cloaked as an IP. + */ + if (chost.length() <= 64) + break; + } + // fall through to IP cloak + } + case MODE_COMPAT_IPONLY: + if (ip.sa.sa_family == AF_INET6) + chost = CompatCloak6(ipstr.c_str()); + else + chost = CompatCloak4(ipstr.c_str()); + break; + case MODE_HALF_CLOAK: + { + if (ipstr != host) + chost = prefix + SegmentCloak(host, 1, 6) + LastTwoDomainParts(host); + if (chost.empty() || chost.length() > 50) + chost = SegmentIP(ip, false); + break; + } + case MODE_OPAQUE: + default: + chost = SegmentIP(ip, true); + } + return chost; + } + + void OnUserConnect(LocalUser* dest) + { + std::string* cloak = cu.ext.get(dest); + if (cloak) + return; + + cu.ext.set(dest, GenCloak(dest->client_sa, dest->GetIPString(), dest->host)); + } +}; + +CmdResult CommandCloak::Handle(const std::vector ¶meters, User *user) { - return new ModuleCloakingFactory; + ModuleCloaking* mod = (ModuleCloaking*)(Module*)creator; + irc::sockets::sockaddrs sa; + std::string cloak; + + if (irc::sockets::aptosa(parameters[0], 0, sa)) + cloak = mod->GenCloak(sa, parameters[0], parameters[0]); + else + cloak = mod->GenCloak(sa, "", parameters[0]); + + user->WriteServ("NOTICE %s :*** Cloak for %s is %s", user->nick.c_str(), parameters[0].c_str(), cloak.c_str()); + + return CMD_SUCCESS; } +MODULE_INIT(ModuleCloaking)