1 /* +------------------------------------+
2 * | Inspire Internet Relay Chat Daemon |
3 * +------------------------------------+
5 * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
7 * <brain@chatspike.net>
8 * <Craig@chatspike.net>
10 * Written by Craig Edwards, Craig McLure, and others.
11 * This program is free but copyrighted software; see
12 * the file COPYING for details.
14 * ---------------------------------------------------
19 // Hostname cloaking (+x mode) module for inspircd.
20 // version 1.0.0.1 by brain (C. J. Edwards) Mar 2004.
22 // When loaded this module will automatically set the
23 // +x mode on all connecting clients.
25 // Setting +x on a client causes the module to change the
26 // dhost entry (displayed host) for each user who has the
27 // mode, cloaking their host. Unlike unreal, the algorithm
28 // is non-reversible as uncloaked hosts are passed along
29 // the server->server link, and all encoding of hosts is
30 // done locally on the server by this module.
32 #include <sys/types.h>
33 #include <sys/socket.h>
34 #include <netinet/in.h>
35 #include <arpa/inet.h>
40 /* $ModDesc: Provides masking of user hostnames */
43 /* The four core functions - F1 is optimized somewhat */
45 #define F1(x, y, z) (z ^ (x & (y ^ z)))
46 #define F2(x, y, z) F1(z, x, y)
47 #define F3(x, y, z) (x ^ y ^ z)
48 #define F4(x, y, z) (y ^ (x | ~z))
49 #define MD5STEP(f,w,x,y,z,in,s) (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
51 typedef unsigned long word32;
52 typedef unsigned char byte;
60 class ModuleCloaking : public Module
66 void byteSwap(word32 *buf, unsigned words)
68 byte *p = (byte *)buf;
72 *buf++ = (word32)((unsigned)p[3] << 8 | p[2]) << 16 |
73 ((unsigned)p[1] << 8 | p[0]);
78 void xMD5Init(struct xMD5Context *ctx)
80 ctx->buf[0] = 0x67452301;
81 ctx->buf[1] = 0xefcdab89;
82 ctx->buf[2] = 0x98badcfe;
83 ctx->buf[3] = 0x10325476;
89 void xMD5Update(struct xMD5Context *ctx, byte const *buf, int len)
93 /* Update byte count */
96 if ((ctx->bytes[0] = t + len) < t)
97 ctx->bytes[1]++; /* Carry from low to high */
99 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
100 if ((unsigned)t > (unsigned)len)
102 memcpy((byte *)ctx->in + 64 - (unsigned)t, buf, len);
105 /* First chunk is an odd size */
106 memcpy((byte *)ctx->in + 64 - (unsigned)t, buf, (unsigned)t);
107 byteSwap(ctx->in, 16);
108 xMD5Transform(ctx->buf, ctx->in);
112 /* Process data in 64-byte chunks */
115 memcpy(ctx->in, buf, 64);
116 byteSwap(ctx->in, 16);
117 xMD5Transform(ctx->buf, ctx->in);
122 /* Handle any remaining bytes of data. */
123 memcpy(ctx->in, buf, len);
126 void xMD5Final(byte digest[16], struct xMD5Context *ctx)
128 int count = (int)(ctx->bytes[0] & 0x3f); /* Bytes in ctx->in */
129 byte *p = (byte *)ctx->in + count; /* First unused byte */
131 /* Set the first char of padding to 0x80. There is always room. */
134 /* Bytes of padding needed to make 56 bytes (-8..55) */
135 count = 56 - 1 - count;
138 { /* Padding forces an extra block */
139 memset(p, 0, count+8);
140 byteSwap(ctx->in, 16);
141 xMD5Transform(ctx->buf, ctx->in);
145 memset(p, 0, count+8);
146 byteSwap(ctx->in, 14);
148 /* Append length in bits and transform */
149 ctx->in[14] = ctx->bytes[0] << 3;
150 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
151 xMD5Transform(ctx->buf, ctx->in);
153 byteSwap(ctx->buf, 4);
154 memcpy(digest, ctx->buf, 16);
155 memset(ctx, 0, sizeof(ctx));
158 void xMD5Transform(word32 buf[4], word32 const in[16])
160 register word32 a, b, c, d;
167 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
168 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
169 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
170 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
171 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
172 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
173 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
174 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
175 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
176 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
177 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
178 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
179 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
180 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
181 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
182 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
184 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
185 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
186 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
187 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
188 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
189 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
190 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
191 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
192 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
193 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
194 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
195 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
196 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
197 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
198 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
199 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
201 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
202 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
203 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
204 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
205 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
206 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
207 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
208 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
209 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
210 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
211 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
212 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
213 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
214 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
215 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
216 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
218 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
219 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
220 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
221 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
222 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
223 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
224 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
225 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
226 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
227 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
228 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
229 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
230 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
231 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
232 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
233 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
242 void MyMD5(void *dest, void *orig, int len)
244 struct xMD5Context context;
247 xMD5Update(&context, (const unsigned char*)orig, len);
248 xMD5Final((unsigned char*)dest, &context);
252 void GenHash(char* src, char* dest)
254 // purposefully lossy md5 - only gives them the most significant 4 bits
255 // of every md5 output byte.
257 unsigned char bytes[16];
260 MyMD5((char*)bytes,src,strlen(src));
261 for (i = 0; i < 16; i++)
263 const char* xtab = "F92E45D871BCA630";
264 unsigned char hi = xtab[bytes[i] / 16];
268 strlcat(hash,hx,MAXBUF);
270 strlcpy(dest,hash,MAXBUF);
274 ModuleCloaking(Server* Me)
277 // We must take a copy of the Server class to work with
280 // we must create a new mode. Set the parameters so the
281 // mode doesn't require oper, and is a client usermode
282 // with no parameters (actually, you cant have params for a umode!)
283 if (!Srv->AddExtendedMode('x',MT_CLIENT,false,0,0))
285 // we couldn't claim mode x... possibly anther module has it,
286 // this might become likely to happen if there are a lot of 3rd
287 // party modules around in the future -- any 3rd party modules
288 // SHOULD implement a system of configurable mode letters (e.g.
289 // from a config file)
290 Srv->Log(DEFAULT,"*** m_cloaking: ERROR, failed to allocate user mode +x!");
291 printf("Could not claim usermode +x for this module!");
296 virtual ~ModuleCloaking()
300 virtual Version GetVersion()
302 // returns the version number of the module to be
303 // listed in /MODULES
304 return Version(1,0,0,1,VF_STATIC|VF_VENDOR);
307 void Implements(char* List)
309 List[I_OnExtendedMode] = List[I_OnUserConnect] = 1;
312 virtual int OnExtendedMode(userrec* user, void* target, char modechar, int type, bool mode_on, string_list ¶ms)
314 // this method is called for any extended mode character.
315 // all module modes for all modules pass through here
316 // (unless another module further up the chain claims them)
317 // so we must be VERY careful to only act upon modes which
318 // we have claimed ourselves. This is a feature to allow
319 // modules to 'spy' on extended mode activity if they so wish.
320 if ((modechar == 'x') && (type == MT_CLIENT))
322 // OnExtendedMode gives us a void* as the target, we must cast
323 // it into a userrec* or a chanrec* depending on the value of
324 // the 'type' parameter (MT_CLIENT or MT_CHANNEL)
325 userrec* dest = (userrec*)target;
327 // we've now determined that this is our mode character...
328 // is the user adding the mode to their list or removing it?
331 // the mode is being turned on - so attempt to
332 // allocate the user a cloaked host using a non-reversible
333 // algorithm (its simple, but its non-reversible so the
334 // simplicity doesnt really matter). This algorithm
335 // will not work if the user has only one level of domain
336 // naming in their hostname (e.g. if they are on a lan or
337 // are connecting via localhost) -- this doesnt matter much.
338 if (strchr(dest->host,'.'))
340 // in inspircd users have two hostnames. A displayed
341 // hostname which can be modified by modules (e.g.
342 // to create vhosts, implement chghost, etc) and a
343 // 'real' hostname which you shouldnt write to.
344 std::string a = strstr(dest->host,".");
346 this->GenHash(dest->host,ra);
349 if (!inet_aton(dest->host,&testaddr))
351 // if they have a hostname, make something appropriate
352 b = Srv->GetNetworkName() + "-" + std::string(ra) + a;
356 // else, they have an ip
357 b = std::string(ra) + "." + Srv->GetNetworkName() + ".cloak";
359 Srv->Log(DEBUG,"cloak: allocated "+b);
360 Srv->ChangeHost(dest,b);
365 // user is removing the mode, so just restore their real host
366 // and make it match the displayed one.
367 Srv->ChangeHost(dest,dest->host);
369 // this mode IS ours, and we have handled it. If we chose not to handle it,
370 // for example the user cannot cloak as they have a vhost or such, then
371 // we could return 0 here instead of 1 and the core would not send the mode
372 // change to the user.
377 // this mode isn't ours, we have to bail and return 0 to not handle it.
382 virtual void OnUserConnect(userrec* user)
384 // Heres the weird bit. When a user connects we must set +x on them, so
385 // we're going to use the SendMode method of the Server class to send
386 // the mode to the client. This is basically the same as sending an
387 // SAMODE in unreal. Note that to the user it will appear as if they set
388 // the mode on themselves.
390 char* modes[2]; // only two parameters
391 modes[0] = user->nick; // first parameter is the nick
392 modes[1] = "+x"; // second parameter is the mode
393 Srv->SendMode(modes,2,user); // send these, forming the command "MODE <nick> +x"
398 // stuff down here is the module-factory stuff. For basic modules you can ignore this.
400 class ModuleCloakingFactory : public ModuleFactory
403 ModuleCloakingFactory()
407 ~ModuleCloakingFactory()
411 virtual Module * CreateModule(Server* Me)
413 return new ModuleCloaking(Me);
419 extern "C" void * init_module( void )
421 return new ModuleCloakingFactory;