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 * ---------------------------------------------------
17 // Hostname cloaking (+x mode) module for inspircd.
18 // version 1.0.0.1 by brain (C. J. Edwards) Mar 2004.
20 // When loaded this module will automatically set the
21 // +x mode on all connecting clients.
23 // Setting +x on a client causes the module to change the
24 // dhost entry (displayed host) for each user who has the
25 // mode, cloaking their host. Unlike unreal, the algorithm
26 // is non-reversible as uncloaked hosts are passed along
27 // the server->server link, and all encoding of hosts is
28 // done locally on the server by this module.
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
34 #include "inspircd_config.h"
38 #include "configreader.h"
44 /* $ModDesc: Provides masking of user hostnames */
48 /* The four core functions - F1 is optimized somewhat */
50 #define F1(x, y, z) (z ^ (x & (y ^ z)))
51 #define F2(x, y, z) F1(z, x, y)
52 #define F3(x, y, z) (x ^ y ^ z)
53 #define F4(x, y, z) (y ^ (x | ~z))
54 #define MD5STEP(f,w,x,y,z,in,s) (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
57 typedef unsigned int uint32_t;
60 typedef uint32_t word32; /* NOT unsigned long. We don't support 16 bit platforms, anyway. */
61 typedef unsigned char byte;
63 /** An MD5 context, used by m_cloaking
65 class xMD5Context : public classbase
73 /** Handles user mode +x
75 class CloakUser : public ModeHandler
84 void byteSwap(word32 *buf, unsigned words)
86 byte *p = (byte *)buf;
90 *buf++ = (word32)((unsigned)p[3] << 8 | p[2]) << 16 |
91 ((unsigned)p[1] << 8 | p[0]);
96 void xMD5Init(struct xMD5Context *ctx)
107 void xMD5Update(struct xMD5Context *ctx, byte const *buf, int len)
111 /* Update byte count */
114 if ((ctx->bytes[0] = t + len) < t)
115 ctx->bytes[1]++; /* Carry from low to high */
117 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
118 if ((unsigned)t > (unsigned)len)
120 memcpy((byte *)ctx->in + 64 - (unsigned)t, buf, len);
123 /* First chunk is an odd size */
124 memcpy((byte *)ctx->in + 64 - (unsigned)t, buf, (unsigned)t);
125 byteSwap(ctx->in, 16);
126 xMD5Transform(ctx->buf, ctx->in);
130 /* Process data in 64-byte chunks */
133 memcpy(ctx->in, buf, 64);
134 byteSwap(ctx->in, 16);
135 xMD5Transform(ctx->buf, ctx->in);
140 /* Handle any remaining bytes of data. */
141 memcpy(ctx->in, buf, len);
144 void xMD5Final(byte digest[16], struct xMD5Context *ctx)
146 int count = (int)(ctx->bytes[0] & 0x3f); /* Bytes in ctx->in */
147 byte *p = (byte *)ctx->in + count; /* First unused byte */
149 /* Set the first char of padding to 0x80. There is always room. */
152 /* Bytes of padding needed to make 56 bytes (-8..55) */
153 count = 56 - 1 - count;
156 { /* Padding forces an extra block */
157 memset(p, 0, count+8);
158 byteSwap(ctx->in, 16);
159 xMD5Transform(ctx->buf, ctx->in);
163 memset(p, 0, count+8);
164 byteSwap(ctx->in, 14);
166 /* Append length in bits and transform */
167 ctx->in[14] = ctx->bytes[0] << 3;
168 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
169 xMD5Transform(ctx->buf, ctx->in);
171 byteSwap(ctx->buf, 4);
172 memcpy(digest, ctx->buf, 16);
173 memset(ctx, 0, sizeof(ctx));
176 void xMD5Transform(word32 buf[4], word32 const in[16])
178 register word32 a, b, c, d;
185 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
186 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
187 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
188 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
189 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
190 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
191 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
192 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
193 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
194 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
195 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
196 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
197 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
198 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
199 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
200 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
202 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
203 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
204 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
205 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
206 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
207 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
208 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
209 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
210 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
211 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
212 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
213 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
214 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
215 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
216 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
217 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
219 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
220 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
221 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
222 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
223 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
224 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
225 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
226 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
227 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
228 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
229 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
230 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
231 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
232 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
233 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
234 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
236 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
237 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
238 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
239 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
240 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
241 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
242 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
243 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
244 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
245 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
246 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
247 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
248 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
249 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
250 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
251 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
260 void MyMD5(void *dest, void *orig, int len)
262 struct xMD5Context context;
265 xMD5Update(&context, (const unsigned char*)orig, len);
266 xMD5Final((unsigned char*)dest, &context);
270 void GenHash(char* src, char* dest)
272 // purposefully lossy md5 - only gives them the most significant 4 bits
273 // of every md5 output byte.
275 unsigned char bytes[16];
278 MyMD5((char*)bytes,src,strlen(src));
279 for (i = 0; i < 16; i++)
281 const char* xtab = "F92E45D871BCA630";
282 unsigned char hi = xtab[bytes[i] / 16];
286 strlcat(hash,hx,MAXBUF);
288 strlcpy(dest,hash,MAXBUF);
292 CloakUser(InspIRCd* Instance) : ModeHandler(Instance, 'x', 0, 0, false, MODETYPE_USER, false) { }
294 ModeAction OnModeChange(userrec* source, userrec* dest, chanrec* channel, std::string ¶meter, bool adding)
296 /* Only opers can change other users modes */
297 if ((source != dest) && (!*source->oper))
298 return MODEACTION_DENY;
300 /* For remote clients, we dont take any action, we just allow it.
301 * The local server where they are will set their cloak instead.
304 return MODEACTION_ALLOW;
308 if(!dest->IsModeSet('x'))
310 /* The mode is being turned on - so attempt to
311 * allocate the user a cloaked host using a non-reversible
312 * algorithm (its simple, but its non-reversible so the
313 * simplicity doesnt really matter). This algorithm
314 * will not work if the user has only one level of domain
315 * naming in their hostname (e.g. if they are on a lan or
316 * are connecting via localhost) -- this doesnt matter much.
319 if (strchr(dest->host,'.') || strchr(dest->host,':'))
321 /* InspIRCd users have two hostnames; A displayed
322 * hostname which can be modified by modules (e.g.
323 * to create vhosts, implement chghost, etc) and a
324 * 'real' hostname which you shouldnt write to.
327 char* n = strstr(dest->host,".");
329 n = strstr(dest->host,":");
334 this->GenHash(dest->host,ra);
336 insp_inaddr testaddr;
337 std::string hostcloak = prefix + "-" + std::string(ra) + a;
339 /* Fix by brain - if the cloaked host is > the max length of a host (64 bytes
340 * according to the DNS RFC) then tough titty, they get cloaked as an IP.
341 * Their ISP shouldnt go to town on subdomains, or they shouldnt have a kiddie
345 if ((insp_aton(dest->host,&testaddr) < 1) && (hostcloak.length() < 64))
347 // if they have a hostname, make something appropriate
352 // else, they have an ip
353 b = std::string(ra) + "." + prefix + ".cloak";
355 ServerInstance->Log(DEBUG,"cloak: allocated "+b);
356 dest->ChangeDisplayedHost(b.c_str());
359 dest->SetMode('x',true);
360 return MODEACTION_ALLOW;
365 if (dest->IsModeSet('x'))
367 /* User is removing the mode, so just restore their real host
368 * and make it match the displayed one.
370 dest->ChangeDisplayedHost(dest->host);
371 dest->SetMode('x',false);
372 return MODEACTION_ALLOW;
376 return MODEACTION_DENY;
381 ConfigReader Conf(ServerInstance);
382 key1 = key2 = key3 = key4 = 0;
383 key1 = Conf.ReadInteger("cloak","key1",0,false);
384 key2 = Conf.ReadInteger("cloak","key2",0,false);
385 key3 = Conf.ReadInteger("cloak","key3",0,false);
386 key4 = Conf.ReadInteger("cloak","key4",0,false);
388 prefix = Conf.ReadValue("cloak","prefix",0);
391 prefix = ServerInstance->Config->Network;
393 if (!key1 && !key2 && !key3 && !key4)
395 ModuleException ex("You have not defined cloak keys for m_cloaking!!! THIS IS INSECURE AND SHOULD BE CHECKED!");
402 class ModuleCloaking : public Module
409 ModuleCloaking(InspIRCd* Me)
412 /* Create new mode handler object */
413 cu = new CloakUser(ServerInstance);
415 /* Register it with the core */
416 ServerInstance->AddMode(cu, 'x');
421 virtual ~ModuleCloaking()
423 ServerInstance->Modes->DelMode(cu);
427 virtual Version GetVersion()
429 // returns the version number of the module to be
430 // listed in /MODULES
431 return Version(1,1,0,2,VF_COMMON|VF_VENDOR,API_VERSION);
434 virtual void OnRehash(const std::string ¶meter)
439 void Implements(char* List)
441 List[I_OnRehash] = 1;
445 // stuff down here is the module-factory stuff. For basic modules you can ignore this.
447 class ModuleCloakingFactory : public ModuleFactory
450 ModuleCloakingFactory()
454 ~ModuleCloakingFactory()
458 virtual Module * CreateModule(InspIRCd* Me)
460 return new ModuleCloaking(Me);
466 extern "C" void * init_module( void )
468 return new ModuleCloakingFactory;