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More ip_cloaking improvements from Spaz.

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The mangling function now creates more variation,
and more of numeric IPs is mangled.
This commit is contained in:
Jilles Tjoelker 2008-09-19 23:35:43 +02:00
parent 14f12985df
commit 3213b626a4
1 changed files with 54 additions and 21 deletions
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75
extensions/ip_cloaking.c
View file

@ -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';
for (tptr = outbuf; *tptr != '\0'; tptr++)
{
if (*tptr == ':' || *tptr == '.')
{
sepcount++;
continue;
}
if(ipv6)
{
rb_snprintf(outbuf, HOSTLEN, "%s:%x", buf, accum);
}
else
{
rb_snprintf(outbuf, HOSTLEN, "%s.%x", buf, accum);
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);
}
}