1 /* +------------------------------------+
2 * | Inspire Internet Relay Chat Daemon |
3 * +------------------------------------+
5 * Inspire is copyright (C) 2002-2004 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.
37 /* $ModDesc: Provides masking of user hostnames */
40 /* The four core functions - F1 is optimized somewhat */
42 #define F1(x, y, z) (z ^ (x & (y ^ z)))
43 #define F2(x, y, z) F1(z, x, y)
44 #define F3(x, y, z) (x ^ y ^ z)
45 #define F4(x, y, z) (y ^ (x | ~z))
46 #define MD5STEP(f,w,x,y,z,in,s) (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
48 typedef unsigned long word32;
49 typedef unsigned char byte;
57 class ModuleCloaking : public Module
63 void byteSwap(word32 *buf, unsigned words)
65 byte *p = (byte *)buf;
69 *buf++ = (word32)((unsigned)p[3] << 8 | p[2]) << 16 |
70 ((unsigned)p[1] << 8 | p[0]);
75 void xMD5Init(struct xMD5Context *ctx)
77 ctx->buf[0] = 0x67452301;
78 ctx->buf[1] = 0xefcdab89;
79 ctx->buf[2] = 0x98badcfe;
80 ctx->buf[3] = 0x10325476;
86 void xMD5Update(struct xMD5Context *ctx, byte const *buf, int len)
90 /* Update byte count */
93 if ((ctx->bytes[0] = t + len) < t)
94 ctx->bytes[1]++; /* Carry from low to high */
96 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
97 if ((unsigned)t > (unsigned)len)
99 memcpy((byte *)ctx->in + 64 - (unsigned)t, buf, len);
102 /* First chunk is an odd size */
103 memcpy((byte *)ctx->in + 64 - (unsigned)t, buf, (unsigned)t);
104 byteSwap(ctx->in, 16);
105 xMD5Transform(ctx->buf, ctx->in);
109 /* Process data in 64-byte chunks */
112 memcpy(ctx->in, buf, 64);
113 byteSwap(ctx->in, 16);
114 xMD5Transform(ctx->buf, ctx->in);
119 /* Handle any remaining bytes of data. */
120 memcpy(ctx->in, buf, len);
123 void xMD5Final(byte digest[16], struct xMD5Context *ctx)
125 int count = (int)(ctx->bytes[0] & 0x3f); /* Bytes in ctx->in */
126 byte *p = (byte *)ctx->in + count; /* First unused byte */
128 /* Set the first char of padding to 0x80. There is always room. */
131 /* Bytes of padding needed to make 56 bytes (-8..55) */
132 count = 56 - 1 - count;
135 { /* Padding forces an extra block */
136 memset(p, 0, count+8);
137 byteSwap(ctx->in, 16);
138 xMD5Transform(ctx->buf, ctx->in);
142 memset(p, 0, count+8);
143 byteSwap(ctx->in, 14);
145 /* Append length in bits and transform */
146 ctx->in[14] = ctx->bytes[0] << 3;
147 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
148 xMD5Transform(ctx->buf, ctx->in);
150 byteSwap(ctx->buf, 4);
151 memcpy(digest, ctx->buf, 16);
152 memset(ctx, 0, sizeof(ctx));
155 void xMD5Transform(word32 buf[4], word32 const in[16])
157 register word32 a, b, c, d;
164 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
165 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
166 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
167 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
168 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
169 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
170 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
171 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
172 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
173 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
174 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
175 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
176 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
177 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
178 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
179 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
181 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
182 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
183 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
184 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
185 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
186 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
187 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
188 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
189 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
190 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
191 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
192 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
193 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
194 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
195 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
196 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
198 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
199 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
200 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
201 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
202 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
203 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
204 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
205 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
206 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
207 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
208 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
209 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
210 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
211 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
212 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
213 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
215 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
216 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
217 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
218 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
219 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
220 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
221 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
222 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
223 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
224 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
225 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
226 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
227 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
228 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
229 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
230 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
239 void MyMD5(void *dest, void *orig, int len)
241 struct xMD5Context context;
244 xMD5Update(&context, (const unsigned char*)orig, len);
245 xMD5Final((unsigned char*)dest, &context);
249 void GenHash(char* src, char* dest)
251 // purposefully lossy md5 - only gives them the most significant 4 bits
252 // of every md5 output byte.
254 unsigned char bytes[16];
257 MyMD5((char*)bytes,src,strlen(src));
258 for (i = 0; i < 16; i++)
260 const char* xtab = "F92E45D871BCA630";
261 unsigned char hi = xtab[bytes[i] / 16];
265 strlcat(hash,hx,MAXBUF);
267 strlcpy(dest,hash,MAXBUF);
273 // We must create an instance of the Server class to work with
276 // we must create a new mode. Set the parameters so the
277 // mode doesn't require oper, and is a client usermode
278 // with no parameters (actually, you cant have params for a umode!)
279 if (!Srv->AddExtendedMode('x',MT_CLIENT,false,0,0))
281 // we couldn't claim mode x... possibly anther module has it,
282 // this might become likely to happen if there are a lot of 3rd
283 // party modules around in the future -- any 3rd party modules
284 // SHOULD implement a system of configurable mode letters (e.g.
285 // from a config file)
286 Srv->Log(DEFAULT,"*** m_cloaking: ERROR, failed to allocate user mode +x!");
287 printf("Could not claim usermode +x for this module!");
292 virtual ~ModuleCloaking()
294 // not really neccessary, but free it anyway
298 virtual Version GetVersion()
300 // returns the version number of the module to be
301 // listed in /MODULES
302 return Version(1,0,0,1,VF_STATIC|VF_VENDOR);
305 virtual int OnExtendedMode(userrec* user, void* target, char modechar, int type, bool mode_on, string_list ¶ms)
307 // this method is called for any extended mode character.
308 // all module modes for all modules pass through here
309 // (unless another module further up the chain claims them)
310 // so we must be VERY careful to only act upon modes which
311 // we have claimed ourselves. This is a feature to allow
312 // modules to 'spy' on extended mode activity if they so wish.
313 if ((modechar == 'x') && (type == MT_CLIENT))
315 // OnExtendedMode gives us a void* as the target, we must cast
316 // it into a userrec* or a chanrec* depending on the value of
317 // the 'type' parameter (MT_CLIENT or MT_CHANNEL)
318 userrec* dest = (userrec*)target;
320 // we've now determined that this is our mode character...
321 // is the user adding the mode to their list or removing it?
324 // the mode is being turned on - so attempt to
325 // allocate the user a cloaked host using a non-reversible
326 // algorithm (its simple, but its non-reversible so the
327 // simplicity doesnt really matter). This algorithm
328 // will not work if the user has only one level of domain
329 // naming in their hostname (e.g. if they are on a lan or
330 // are connecting via localhost) -- this doesnt matter much.
331 if (strchr(dest->host,'.'))
333 // in inspircd users have two hostnames. A displayed
334 // hostname which can be modified by modules (e.g.
335 // to create vhosts, implement chghost, etc) and a
336 // 'real' hostname which you shouldnt write to.
337 std::string a = strstr(dest->host,".");
339 this->GenHash(dest->host,ra);
342 if (!inet_aton(dest->host,&testaddr))
344 // if they have a hostname, make something appropriate
345 b = Srv->GetNetworkName() + "-" + std::string(ra) + a;
349 // else, they have an ip
350 b = std::string(ra) + "." + Srv->GetNetworkName() + ".cloak";
352 Srv->Log(DEBUG,"cloak: allocated "+b);
353 Srv->ChangeHost(dest,b);
358 // user is removing the mode, so just restore their real host
359 // and make it match the displayed one.
360 Srv->ChangeHost(dest,dest->host);
362 // this mode IS ours, and we have handled it. If we chose not to handle it,
363 // for example the user cannot cloak as they have a vhost or such, then
364 // we could return 0 here instead of 1 and the core would not send the mode
365 // change to the user.
370 // this mode isn't ours, we have to bail and return 0 to not handle it.
375 virtual void OnUserConnect(userrec* user)
377 // Heres the weird bit. When a user connects we must set +x on them, so
378 // we're going to use the SendMode method of the Server class to send
379 // the mode to the client. This is basically the same as sending an
380 // SAMODE in unreal. Note that to the user it will appear as if they set
381 // the mode on themselves.
383 char* modes[2]; // only two parameters
384 modes[0] = user->nick; // first parameter is the nick
385 modes[1] = "+x"; // second parameter is the mode
386 Srv->SendMode(modes,2,user); // send these, forming the command "MODE <nick> +x"
391 // stuff down here is the module-factory stuff. For basic modules you can ignore this.
393 class ModuleCloakingFactory : public ModuleFactory
396 ModuleCloakingFactory()
400 ~ModuleCloakingFactory()
404 virtual Module * CreateModule()
406 return new ModuleCloaking;
412 extern "C" void * init_module( void )
414 return new ModuleCloakingFactory;