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 CloakUser(Module* source)
42 : ModeHandler(source, "cloak", 'x', PARAM_NONE, MODETYPE_USER),
43 ext("cloaked_host", source)
47 ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string ¶meter, bool adding)
49 /* For remote clients, we don't take any action, we just allow it.
50 * The local server where they are will set their cloak instead.
51 * This is fine, as we will receive it later.
55 dest->SetMode('x',adding);
56 return MODEACTION_ALLOW;
59 /* don't allow this user to spam modechanges */
60 IS_LOCAL(dest)->CommandFloodPenalty += 5000;
64 if(!dest->IsModeSet('x'))
66 /* The mode is being turned on - so attempt to
67 * allocate the user a cloaked host using a non-reversible
68 * algorithm (its simple, but its non-reversible so the
69 * simplicity doesnt really matter). This algorithm
70 * will not work if the user has only one level of domain
71 * naming in their hostname (e.g. if they are on a lan or
72 * are connecting via localhost) -- this doesnt matter much.
75 std::string* cloak = ext.get(dest);
77 if (!cloak && IS_LOCAL(dest))
79 /* Force creation of missing cloak */
80 creator->OnUserConnect(IS_LOCAL(dest));
81 cloak = ext.get(dest);
85 dest->ChangeDisplayedHost(cloak->c_str());
86 dest->SetMode('x',true);
87 return MODEACTION_ALLOW;
93 if (dest->IsModeSet('x'))
95 /* User is removing the mode, so just restore their real host
96 * and make it match the displayed one.
98 dest->ChangeDisplayedHost(dest->host.c_str());
99 dest->SetMode('x',false);
100 return MODEACTION_ALLOW;
104 return MODEACTION_DENY;
110 class ModuleCloaking : public Module
117 unsigned int compatkey[4];
119 dynamic_reference<HashProvider> Hash;
122 ModuleCloaking() : cu(this), Hash(this, "hash/md5")
126 /* Register it with the core */
127 if (!ServerInstance->Modes->AddMode(&cu))
128 throw ModuleException("Could not add new modes!");
130 ServerInstance->Extensions.Register(&cu.ext);
132 Implementation eventlist[] = { I_OnRehash, I_OnCheckBan, I_OnUserConnect };
133 ServerInstance->Modules->Attach(eventlist, this, 3);
136 /** This function takes a domain name string and returns just the last two domain parts,
137 * or the last domain part if only two are available. Failing that it just returns what it was given.
139 * For example, if it is passed "svn.inspircd.org" it will return ".inspircd.org".
140 * If it is passed "brainbox.winbot.co.uk" it will return ".co.uk",
141 * and if it is passed "localhost.localdomain" it will return ".localdomain".
143 * This is used to ensure a significant part of the host is always cloaked (see Bug #216)
145 std::string LastTwoDomainParts(const std::string &host)
148 std::string::size_type splitdot = host.length();
150 for (std::string::size_type x = host.length() - 1; x; --x)
161 if (splitdot == host.length())
164 return host.substr(splitdot);
167 std::string CompatCloak4(const char* ip)
169 irc::sepstream seps(ip, '.');
170 std::string octet[4];
173 for (int j = 0; j < 4; j++)
175 seps.GetToken(octet[j]);
176 i[j] = atoi(octet[j].c_str());
179 octet[3] = octet[0] + "." + octet[1] + "." + octet[2] + "." + octet[3];
180 octet[2] = octet[0] + "." + octet[1] + "." + octet[2];
181 octet[1] = octet[0] + "." + octet[1];
183 /* Reset the Hash module and send it our IV */
187 /* Send the Hash module a different hex table for each octet group's Hash sum */
188 for (int k = 0; k < 4; k++)
190 rv.append(Hash->sumIV(compatkey, xtab[(compatkey[k]+i[k]) % 4], octet[k]).substr(0,6));
194 /* Stick them all together */
198 std::string CompatCloak6(const char* ip)
200 std::vector<std::string> hashies;
204 /* Reset the Hash module and send it our IV */
206 for (const char* input = ip; *input; input++)
209 if (item.length() > 7)
211 hashies.push_back(Hash->sumIV(compatkey, xtab[(compatkey[1]+rounds) % 4], item).substr(0,8));
218 hashies.push_back(Hash->sumIV(compatkey, xtab[(compatkey[1]+rounds) % 4], item).substr(0,8));
220 /* Stick them all together */
221 return irc::stringjoiner(":", hashies, 0, hashies.size() - 1).GetJoined();
224 std::string SegmentIP(const irc::sockets::sockaddrs& ip, bool full)
227 int hop1, hop2, hop3;
229 if (ip.sa.sa_family == AF_INET6)
231 bindata = std::string((const char*)ip.in6.sin6_addr.s6_addr, 16);
235 rv.reserve(prefix.length() + 37);
239 bindata = std::string((const char*)&ip.in4.sin_addr, 4);
243 rv.reserve(prefix.length() + 30);
247 rv.append(SegmentCloak(bindata, 10));
250 rv.append(SegmentCloak(bindata, 11));
255 rv.append(SegmentCloak(bindata, 12));
262 rv.append(SegmentCloak(bindata, 13));
268 if (ip.sa.sa_family == AF_INET6)
270 snprintf(buf, 50, ".%02x%02x.%02x%02x.IP",
271 ip.in6.sin6_addr.s6_addr[2], ip.in6.sin6_addr.s6_addr[3],
272 ip.in6.sin6_addr.s6_addr[0], ip.in6.sin6_addr.s6_addr[1]);
276 const unsigned char* ip4 = (const unsigned char*)&ip.in4.sin_addr;
277 snprintf(buf, 50, ".%d.%d.IP", ip4[1], ip4[0]);
284 std::string SegmentCloak(const std::string& item, char id)
287 input.reserve(key.length() + 3 + item.length());
290 input.append(1, 0); // null does not terminate a C++ string
293 std::string rv = Hash->sum(input).substr(0,6);
294 for(int i=0; i < 6; i++)
296 // this discards 3 bits per byte. We have an
297 // overabundance of bits in the hash output, doesn't
298 // matter which ones we are discarding.
299 rv[i] = base32[rv[i] & 0x1F];
304 ModResult OnCheckBan(User* user, Channel* chan, const std::string& mask)
306 LocalUser* lu = IS_LOCAL(user);
308 return MOD_RES_PASSTHRU;
311 std::string* cloak = cu.ext.get(user);
312 /* Check if they have a cloaked host, but are not using it */
313 if (cloak && *cloak != user->dhost)
316 snprintf(cmask, MAXBUF, "%s!%s@%s", user->nick.c_str(), user->ident.c_str(), cloak->c_str());
317 if (InspIRCd::Match(cmask,mask))
320 return MOD_RES_PASSTHRU;
325 /* Needs to be after m_banexception etc. */
326 ServerInstance->Modules->SetPriority(this, I_OnCheckBan, PRIORITY_LAST);
335 std::string testcloak;
338 case MODE_COMPAT_HOST:
339 testcloak = prefix + "-" + Hash->sumIV(compatkey, xtab[0], "*").substr(0,10);
341 case MODE_COMPAT_IPONLY:
342 testcloak = Hash->sumIV(compatkey, xtab[0], "*").substr(0,10);
344 case MODE_HALF_CLOAK:
345 testcloak = prefix + SegmentCloak("*", 3);
349 testcloak = prefix + SegmentCloak("*", 4);
351 return Version("Provides masking of user hostnames", VF_COMMON|VF_VENDOR, testcloak);
354 void OnRehash(User* user)
357 prefix = Conf.ReadValue("cloak","prefix",0);
359 std::string modestr = Conf.ReadValue("cloak", "mode", 0);
360 if (modestr == "compat-host")
361 mode = MODE_COMPAT_HOST;
362 else if (modestr == "compat-ip")
363 mode = MODE_COMPAT_IPONLY;
364 else if (modestr == "half")
365 mode = MODE_HALF_CLOAK;
366 else if (modestr == "full")
369 throw ModuleException("Bad value for <cloak:mode>; must be one of compat-host, compat-ip, half, full");
371 if (mode == MODE_COMPAT_HOST || mode == MODE_COMPAT_IPONLY)
373 bool lowercase = Conf.ReadFlag("cloak", "lowercase", 0);
375 /* These are *not* using the need_positive parameter of ReadInteger -
376 * that will limit the valid values to only the positive values in a
377 * signed int. Instead, accept any value that fits into an int and
378 * cast it to an unsigned int. That will, a bit oddly, give us the full
379 * spectrum of an unsigned integer. - Special
381 * We must limit the keys or else we get different results on
382 * amd64/x86 boxes. - psychon */
383 const unsigned int limit = 0x80000000;
384 compatkey[0] = (unsigned int) Conf.ReadInteger("cloak","key1",0,false);
385 compatkey[1] = (unsigned int) Conf.ReadInteger("cloak","key2",0,false);
386 compatkey[2] = (unsigned int) Conf.ReadInteger("cloak","key3",0,false);
387 compatkey[3] = (unsigned int) Conf.ReadInteger("cloak","key4",0,false);
391 xtab[0] = "F92E45D871BCA630";
392 xtab[1] = "A1B9D80C72E653F4";
393 xtab[2] = "1ABC078934DEF562";
394 xtab[3] = "ABCDEF5678901234";
398 xtab[0] = "f92e45d871bca630";
399 xtab[1] = "a1b9d80c72e653f4";
400 xtab[2] = "1abc078934def562";
401 xtab[3] = "abcdef5678901234";
405 prefix = ServerInstance->Config->Network;
407 if (!compatkey[0] || !compatkey[1] || !compatkey[2] || !compatkey[3] ||
408 compatkey[0] >= limit || compatkey[1] >= limit || compatkey[2] >= limit || compatkey[3] >= limit)
411 if (!compatkey[0] || compatkey[0] >= limit)
412 detail = "<cloak:key1> is not valid, it may be set to a too high/low value, or it may not exist.";
413 else if (!compatkey[1] || compatkey[1] >= limit)
414 detail = "<cloak:key2> is not valid, it may be set to a too high/low value, or it may not exist.";
415 else if (!compatkey[2] || compatkey[2] >= limit)
416 detail = "<cloak:key3> is not valid, it may be set to a too high/low value, or it may not exist.";
417 else if (!compatkey[3] || compatkey[3] >= limit)
418 detail = "<cloak:key4> is not valid, it may be set to a too high/low value, or it may not exist.";
420 throw ModuleException("You have not defined cloak keys for m_cloaking!!! THIS IS INSECURE AND SHOULD BE CHECKED! - " + detail);
425 key = Conf.ReadFlag("cloak", "key", 0);
426 if (key.empty() || key == "secret")
427 throw ModuleException("You have not defined cloak keys for m_cloaking. Define <cloak:key> as a network-wide secret.");
431 void OnUserConnect(LocalUser* dest)
433 std::string* cloak = cu.ext.get(dest);
437 if (dest->host.find('.') == std::string::npos && dest->host.find(':') == std::string::npos)
440 std::string ipstr = dest->GetIPString();
445 case MODE_COMPAT_HOST:
447 if (ipstr != dest->host)
449 std::string tail = LastTwoDomainParts(dest->host);
451 /* Generate a cloak using specialized Hash */
452 chost = prefix + "-" + Hash->sumIV(compatkey, xtab[(dest->host[0]) % 4], dest->host).substr(0,8) + tail;
454 /* Fix by brain - if the cloaked host is > the max length of a host (64 bytes
455 * according to the DNS RFC) then they get cloaked as an IP.
457 if (chost.length() <= 64)
460 // fall through to IP cloak
462 case MODE_COMPAT_IPONLY:
463 if (dest->client_sa.sa.sa_family == AF_INET6)
464 chost = CompatCloak6(ipstr.c_str());
466 chost = CompatCloak4(ipstr.c_str());
468 case MODE_HALF_CLOAK:
470 if (ipstr != dest->host)
471 chost = prefix + SegmentCloak(dest->host, 1) + LastTwoDomainParts(dest->host);
472 if (chost.empty() || chost.length() > 50)
473 chost = SegmentIP(dest->client_sa, false);
478 chost = SegmentIP(dest->client_sa, true);
480 cu.ext.set(dest,chost);
485 MODULE_INIT(ModuleCloaking)