More ip_cloaking improvements from Spaz.

The mangling function now creates more variation,
and more of numeric IPs is mangled.

diff --git a/extensions/ip_cloaking.c b/extensions/ip_cloaking.c
index 09aabeb9f4ef07c932c82b5a1f941db7f840345e..e60ef4c280366afef6a2ff6c0664eef8d66565df 100644 (file)
--- a/extensions/ip_cloaking.c
+++ b/extensions/ip_cloaking.c
@@ -6,6 +6,7 @@
 #include "client.h"
 #include "ircd.h"
 #include "send.h"
+#include "hash.h"
 #include "s_conf.h"
 #include "s_user.h"
 #include "s_serv.h"
@@ -70,35 +71,62 @@ distribute_hostchange(struct Client *client)
 static void
 do_host_cloak_ip(const char *inbuf, char *outbuf)
 {
+       /* None of the characters in this table can be valid in an IP */
+       char chartable[] = "ghijklmnopqrstuvwxyz";
        char *tptr;
-       unsigned int accum = fnv_hash(inbuf, 32);
-       char buf[HOSTLEN];
+       uint32_t accum = fnv_hash((const unsigned char*) inbuf, 32);
+       int sepcount = 0;
+       int totalcount = 0;
        int ipv6 = 0;
 
-       strncpy(buf, inbuf, HOSTLEN);
-       tptr = strrchr(buf, '.');
+       strncpy(outbuf, inbuf, HOSTLEN);
 
-       if (tptr == NULL)
+       if (strchr(outbuf, ':'))
        {
-               tptr = strrchr(buf, ':');
                ipv6 = 1;
-       }
 
-       if (tptr == NULL)
+               /* Damn you IPv6... 
+                * We count the number of colons so we can calculate how much
+                * of the host to cloak. This is because some hostmasks may not
+                * have as many octets as we'd like.
+                *
+                * We have to do this ahead of time because doing this during
+                * the actual cloaking would get ugly
+                */
+               for (tptr = outbuf; *tptr != '\0'; tptr++)
+               {
+                       if (*tptr == ':') {
+                               totalcount++;
+                       }
+               }
+       }
+       else if (!strchr(outbuf, '.'))
        {
-               strncpy(outbuf, inbuf, HOSTLEN);
                return;
        }
 
-       *tptr++ = '\0';
-
-       if(ipv6)
+       for (tptr = outbuf; *tptr != '\0'; tptr++) 
        {
-           rb_snprintf(outbuf, HOSTLEN, "%s:%x", buf, accum);
-       }
-       else
-       {
-           rb_snprintf(outbuf, HOSTLEN, "%s.%x", buf, accum);
+               if (*tptr == ':' || *tptr == '.')
+               {
+                       sepcount++;
+                       continue;
+               }
+
+               switch (ipv6)
+               {
+               case 1:
+                       if (sepcount < totalcount / 2)
+                               break;
+               case 0:
+                       if (sepcount < 2)
+                               break;
+               default:
+                       *tptr = chartable[(*tptr + accum) % 20];
+
+               }
+
+               accum = (accum << 1) | (accum >> 31);
        }
 }
 
@@ -107,12 +135,12 @@ do_host_cloak_host(const char *inbuf, char *outbuf)
 {
        char b26_alphabet[] = "abcdefghijklmnopqrstuvwxyz";
        char *tptr;
-       unsigned int accum = fnv_hash(inbuf, 32);
+       uint32_t accum = fnv_hash((const unsigned char*) inbuf, 32);
 
        strncpy(outbuf, inbuf, HOSTLEN);
 
        /* pass 1: scramble first section of hostname using base26 
-        * alphabet toasted against the weighted entropy of the string.
+        * alphabet toasted against the FNV hash of the string.
         *
         * numbers are not changed at this time, only letters.
         */
@@ -124,7 +152,10 @@ do_host_cloak_host(const char *inbuf, char *outbuf)
                if (isdigit(*tptr) || *tptr == '-')
                        continue;
 
-               *tptr = b26_alphabet[(*tptr * accum) % 26];
+               *tptr = b26_alphabet[(*tptr + accum) % 26];
+
+               /* Rotate one bit to avoid all digits being turned odd or even */
+               accum = (accum << 1) | (accum >> 31);
        }
 
        /* pass 2: scramble each number in the address */
@@ -132,8 +163,10 @@ do_host_cloak_host(const char *inbuf, char *outbuf)
        {
                if (isdigit(*tptr))
                {
-                       *tptr = 48 + ((*tptr * accum) % 10);
+                       *tptr = (*tptr + accum) % 10;
                }
+
+               accum = (accum << 1) | (accum >> 31);
        }       
 }