-// 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"
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ * Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
+ * Copyright (C) 2006-2008 Robin Burchell <robin+git@viroteck.net>
+ * Copyright (C) 2008 Pippijn van Steenhoven <pip88nl@gmail.com>
+ * Copyright (C) 2003-2008 Craig Edwards <craigedwards@brainbox.cc>
+ * Copyright (C) 2007 John Brooks <john.brooks@dereferenced.net>
+ * Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
+ * Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+
+#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 <nick> +x"
+ flags_needed = 'o';
+ syntax = "<host>";
}
+ CmdResult Handle(const std::vector<std::string> ¶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<HashProvider> 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<std::string> 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 <cloak:mode>; 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 = "<cloak:key1> 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 = "<cloak:key2> 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 = "<cloak:key3> 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 = "<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);
+ }
+ }
+ else
+ {
+ key = tag->getString("key");
+ if (key.empty() || key == "secret")
+ throw ModuleException("You have not defined cloak keys for m_cloaking. Define <cloak:key> 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<std::string> ¶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)
projects / user / henk / code / inspircd.git / blobdiff