1 /* +------------------------------------+
2 * | Inspire Internet Relay Chat Daemon |
3 * +------------------------------------+
5 * InspIRCd: (C) 2002-2010 InspIRCd Development Team
6 * See: http://wiki.inspircd.org/Credits
8 * This program is free but copyrighted software; see
9 * the file COPYING for details.
11 * ---------------------------------------------------
17 /* $ModDesc: Provides masking of user hostnames */
21 /** 1.2-compatible host-based cloak */
23 /** 1.2-compatible IP-only cloak */
25 /** 2.0 cloak of "half" of the hostname plus the full IP hash */
27 /** 2.0 cloak of IP hash, split at 2 common CIDR range points */
31 // lowercase-only encoding similar to base64, used for hash output
32 static const char base32[] = "0123456789abcdefghijklmnopqrstuv";
34 /** Handles user mode +x
36 class CloakUser : public ModeHandler
41 std::string debounce_uid;
45 CloakUser(Module* source)
46 : ModeHandler(source, "cloak", 'x', PARAM_NONE, MODETYPE_USER),
47 ext("cloaked_host", source), debounce_ts(0), debounce_count(0)
51 ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string ¶meter, bool adding)
53 LocalUser* user = IS_LOCAL(dest);
55 /* For remote clients, we don't take any action, we just allow it.
56 * The local server where they are will set their cloak instead.
57 * This is fine, as we will receive it later.
61 dest->SetMode('x',adding);
62 return MODEACTION_ALLOW;
65 if (user->uuid == debounce_uid && debounce_ts == ServerInstance->Time())
67 // prevent spamming using /mode user +x-x+x-x+x-x
68 if (++debounce_count > 2)
69 return MODEACTION_DENY;
73 debounce_uid = user->uuid;
75 debounce_ts = ServerInstance->Time();
78 if (adding == user->IsModeSet('x'))
79 return MODEACTION_DENY;
81 /* don't allow this user to spam modechanges */
83 user->CommandFloodPenalty += 5000;
87 std::string* cloak = ext.get(user);
91 /* Force creation of missing cloak */
92 creator->OnUserConnect(user);
93 cloak = ext.get(user);
97 user->ChangeDisplayedHost(cloak->c_str());
98 user->SetMode('x',true);
99 return MODEACTION_ALLOW;
102 return MODEACTION_DENY;
106 /* User is removing the mode, so restore their real host
107 * and make it match the displayed one.
109 user->SetMode('x',false);
110 user->ChangeDisplayedHost(user->host.c_str());
111 return MODEACTION_ALLOW;
117 class CommandCloak : public Command
120 CommandCloak(Module* Creator) : Command(Creator, "CLOAK", 1)
126 CmdResult Handle(const std::vector<std::string> ¶meters, User *user);
129 class ModuleCloaking : public Module
138 unsigned int compatkey[4];
140 dynamic_reference<HashProvider> Hash;
142 ModuleCloaking() : cu(this), mode(MODE_OPAQUE), ck(this), Hash(this, "hash/md5")
150 ServerInstance->Modules->AddService(cu);
151 ServerInstance->Modules->AddService(ck);
152 ServerInstance->Modules->AddService(cu.ext);
154 Implementation eventlist[] = { I_OnRehash, I_OnCheckBan, I_OnUserConnect, I_OnChangeHost };
155 ServerInstance->Modules->Attach(eventlist, this, 4);
158 /** This function takes a domain name string and returns just the last two domain parts,
159 * or the last domain part if only two are available. Failing that it just returns what it was given.
161 * For example, if it is passed "svn.inspircd.org" it will return ".inspircd.org".
162 * If it is passed "brainbox.winbot.co.uk" it will return ".co.uk",
163 * and if it is passed "localhost.localdomain" it will return ".localdomain".
165 * This is used to ensure a significant part of the host is always cloaked (see Bug #216)
167 std::string LastTwoDomainParts(const std::string &host)
170 std::string::size_type splitdot = host.length();
172 for (std::string::size_type x = host.length() - 1; x; --x)
183 if (splitdot == host.length())
186 return host.substr(splitdot);
190 * 2.0-style cloaking function
191 * @param item The item to cloak (part of an IP or hostname)
192 * @param id A unique ID for this type of item (to make it unique if the item matches)
193 * @param len The length of the output. Maximum for MD5 is 16 characters.
195 std::string SegmentCloak(const std::string& item, char id, int len)
198 input.reserve(key.length() + 3 + item.length());
201 input.append(1, '\0'); // null does not terminate a C++ string
204 std::string rv = Hash->sum(input).substr(0,len);
205 for(int i=0; i < len; i++)
207 // this discards 3 bits per byte. We have an
208 // overabundance of bits in the hash output, doesn't
209 // matter which ones we are discarding.
210 rv[i] = base32[rv[i] & 0x1F];
215 std::string CompatCloak4(const char* ip)
217 irc::sepstream seps(ip, '.');
218 std::string octet[4];
221 for (int j = 0; j < 4; j++)
223 seps.GetToken(octet[j]);
224 i[j] = atoi(octet[j].c_str());
227 octet[3] = octet[0] + "." + octet[1] + "." + octet[2] + "." + octet[3];
228 octet[2] = octet[0] + "." + octet[1] + "." + octet[2];
229 octet[1] = octet[0] + "." + octet[1];
231 /* Reset the Hash module and send it our IV */
235 /* Send the Hash module a different hex table for each octet group's Hash sum */
236 for (int k = 0; k < 4; k++)
238 rv.append(Hash->sumIV(compatkey, xtab[(compatkey[k]+i[k]) % 4], octet[k]).substr(0,6));
242 /* Stick them all together */
246 std::string CompatCloak6(const char* ip)
248 std::vector<std::string> hashies;
252 /* Reset the Hash module and send it our IV */
254 for (const char* input = ip; *input; input++)
257 if (item.length() > 7)
259 hashies.push_back(Hash->sumIV(compatkey, xtab[(compatkey[0]+rounds) % 4], item).substr(0,8));
266 hashies.push_back(Hash->sumIV(compatkey, xtab[(compatkey[0]+rounds) % 4], item).substr(0,8));
268 /* Stick them all together */
269 return irc::stringjoiner(":", hashies, 0, hashies.size() - 1).GetJoined();
272 std::string SegmentIP(const irc::sockets::sockaddrs& ip, bool full)
275 int hop1, hop2, hop3;
278 if (ip.sa.sa_family == AF_INET6)
280 bindata = std::string((const char*)ip.in6.sin6_addr.s6_addr, 16);
286 // pfx s1.s2.s3. (xxxx.xxxx or s4) sfx
288 rv.reserve(prefix.length() + 26 + suffix.length());
292 bindata = std::string((const char*)&ip.in4.sin_addr, 4);
297 // pfx s1.s2. (xxx.xxx or s3) sfx
298 rv.reserve(prefix.length() + 15 + suffix.length());
302 rv.append(SegmentCloak(bindata, 10, len1));
305 rv.append(SegmentCloak(bindata, 11, len2));
310 rv.append(SegmentCloak(bindata, 12, len2));
317 rv.append(SegmentCloak(bindata, 13, 6));
323 if (ip.sa.sa_family == AF_INET6)
325 snprintf(buf, 50, ".%02x%02x.%02x%02x%s",
326 ip.in6.sin6_addr.s6_addr[2], ip.in6.sin6_addr.s6_addr[3],
327 ip.in6.sin6_addr.s6_addr[0], ip.in6.sin6_addr.s6_addr[1], suffix.c_str());
331 const unsigned char* ip4 = (const unsigned char*)&ip.in4.sin_addr;
332 snprintf(buf, 50, ".%d.%d%s", ip4[1], ip4[0], suffix.c_str());
339 ModResult OnCheckBan(User* user, Channel* chan, const std::string& mask)
341 LocalUser* lu = IS_LOCAL(user);
343 return MOD_RES_PASSTHRU;
346 std::string* cloak = cu.ext.get(user);
347 /* Check if they have a cloaked host, but are not using it */
348 if (cloak && *cloak != user->dhost)
351 snprintf(cmask, MAXBUF, "%s!%s@%s", user->nick.c_str(), user->ident.c_str(), cloak->c_str());
352 if (InspIRCd::Match(cmask,mask))
355 return MOD_RES_PASSTHRU;
360 /* Needs to be after m_banexception etc. */
361 ServerInstance->Modules->SetPriority(this, I_OnCheckBan, PRIORITY_LAST);
364 // this unsets umode +x on every host change. If we are actually doing a +x
365 // mode change, we will call SetMode back to true AFTER the host change is done.
366 void OnChangeHost(User* u, const std::string& host)
368 if(u->IsModeSet('x'))
370 u->SetMode('x', false);
371 u->WriteServ("MODE %s -x", u->nick.c_str());
381 std::string testcloak = "broken";
386 case MODE_COMPAT_HOST:
387 testcloak = prefix + "-" + Hash->sumIV(compatkey, xtab[0], "*").substr(0,10);
389 case MODE_COMPAT_IPONLY:
390 testcloak = Hash->sumIV(compatkey, xtab[0], "*").substr(0,10);
392 case MODE_HALF_CLOAK:
393 testcloak = prefix + SegmentCloak("*", 3, 8) + suffix;
396 testcloak = prefix + SegmentCloak("*", 4, 8) + suffix;
399 return Version("Provides masking of user hostnames", VF_COMMON|VF_VENDOR, testcloak);
402 void OnRehash(User* user)
404 ConfigTag* tag = ServerInstance->Config->ConfValue("cloak");
405 prefix = tag->getString("prefix");
406 suffix = tag->getString("suffix", ".IP");
408 std::string modestr = tag->getString("mode");
409 if (modestr == "compat-host")
410 mode = MODE_COMPAT_HOST;
411 else if (modestr == "compat-ip")
412 mode = MODE_COMPAT_IPONLY;
413 else if (modestr == "half")
414 mode = MODE_HALF_CLOAK;
415 else if (modestr == "full")
418 throw ModuleException("Bad value for <cloak:mode>; must be one of compat-host, compat-ip, half, full");
420 if (mode == MODE_COMPAT_HOST || mode == MODE_COMPAT_IPONLY)
422 bool lowercase = tag->getBool("lowercase");
424 /* These are *not* using the need_positive parameter of ReadInteger -
425 * that will limit the valid values to only the positive values in a
426 * signed int. Instead, accept any value that fits into an int and
427 * cast it to an unsigned int. That will, a bit oddly, give us the full
428 * spectrum of an unsigned integer. - Special
430 * We must limit the keys or else we get different results on
431 * amd64/x86 boxes. - psychon */
432 const unsigned int limit = 0x80000000;
433 compatkey[0] = (unsigned int) tag->getInt("key1");
434 compatkey[1] = (unsigned int) tag->getInt("key2");
435 compatkey[2] = (unsigned int) tag->getInt("key3");
436 compatkey[3] = (unsigned int) tag->getInt("key4");
440 xtab[0] = "F92E45D871BCA630";
441 xtab[1] = "A1B9D80C72E653F4";
442 xtab[2] = "1ABC078934DEF562";
443 xtab[3] = "ABCDEF5678901234";
447 xtab[0] = "f92e45d871bca630";
448 xtab[1] = "a1b9d80c72e653f4";
449 xtab[2] = "1abc078934def562";
450 xtab[3] = "abcdef5678901234";
454 prefix = ServerInstance->Config->Network;
456 if (!compatkey[0] || !compatkey[1] || !compatkey[2] || !compatkey[3] ||
457 compatkey[0] >= limit || compatkey[1] >= limit || compatkey[2] >= limit || compatkey[3] >= limit)
460 if (!compatkey[0] || compatkey[0] >= limit)
461 detail = "<cloak:key1> is not valid, it may be set to a too high/low value, or it may not exist.";
462 else if (!compatkey[1] || compatkey[1] >= limit)
463 detail = "<cloak:key2> is not valid, it may be set to a too high/low value, or it may not exist.";
464 else if (!compatkey[2] || compatkey[2] >= limit)
465 detail = "<cloak:key3> is not valid, it may be set to a too high/low value, or it may not exist.";
466 else if (!compatkey[3] || compatkey[3] >= limit)
467 detail = "<cloak:key4> is not valid, it may be set to a too high/low value, or it may not exist.";
469 throw ModuleException("You have not defined cloak keys for m_cloaking!!! THIS IS INSECURE AND SHOULD BE CHECKED! - " + detail);
474 key = tag->getString("key");
475 if (key.empty() || key == "secret")
476 throw ModuleException("You have not defined cloak keys for m_cloaking. Define <cloak:key> as a network-wide secret.");
480 std::string GenCloak(const irc::sockets::sockaddrs& ip, const std::string& ipstr, const std::string& host)
486 case MODE_COMPAT_HOST:
490 std::string tail = LastTwoDomainParts(host);
492 // xtab is not used here due to a bug in 1.2 cloaking
493 chost = prefix + "-" + Hash->sumIV(compatkey, "0123456789abcdef", host).substr(0,8) + tail;
495 /* Fix by brain - if the cloaked host is > the max length of a host (64 bytes
496 * according to the DNS RFC) then they get cloaked as an IP.
498 if (chost.length() <= 64)
501 // fall through to IP cloak
503 case MODE_COMPAT_IPONLY:
504 if (ip.sa.sa_family == AF_INET6)
505 chost = CompatCloak6(ipstr.c_str());
507 chost = CompatCloak4(ipstr.c_str());
509 case MODE_HALF_CLOAK:
512 chost = prefix + SegmentCloak(host, 1, 6) + LastTwoDomainParts(host);
513 if (chost.empty() || chost.length() > 50)
514 chost = SegmentIP(ip, false);
519 chost = SegmentIP(ip, true);
524 void OnUserConnect(LocalUser* dest)
526 std::string* cloak = cu.ext.get(dest);
530 cu.ext.set(dest, GenCloak(dest->client_sa, dest->GetIPString(), dest->host));
534 CmdResult CommandCloak::Handle(const std::vector<std::string> ¶meters, User *user)
536 ModuleCloaking* mod = (ModuleCloaking*)(Module*)creator;
537 irc::sockets::sockaddrs sa;
540 if (irc::sockets::aptosa(parameters[0], 0, sa))
541 cloak = mod->GenCloak(sa, parameters[0], parameters[0]);
543 cloak = mod->GenCloak(sa, "", parameters[0]);
545 user->WriteServ("NOTICE %s :*** Cloak for %s is %s", user->nick.c_str(), parameters[0].c_str(), cloak.c_str());
550 MODULE_INIT(ModuleCloaking)