158 lines
3 KiB
C
158 lines
3 KiB
C
/*
|
|
* keygen.c
|
|
* WEP Key Generators
|
|
*
|
|
* This program generates WEP keys using de facto standard key
|
|
* generators for 40 and 128 bit keys.
|
|
*
|
|
* Link against OpenSSL's libcrypto.a
|
|
*
|
|
* I place this code in the public domain.
|
|
* May 2001, Tim Newsham
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/types.h>
|
|
#include <openssl/md5.h>
|
|
|
|
#define WEPKEYSIZE 5
|
|
#define WEPSTRONGKEYSIZE 13
|
|
#define WEPKEYS 4
|
|
#define WEPKEYSTORE (WEPKEYSIZE * WEPKEYS)
|
|
|
|
/*
|
|
* generate four subkeys from a seed using the defacto standard
|
|
*/
|
|
void
|
|
wep_seedkeygen(int val, u_char *keys)
|
|
{
|
|
int i;
|
|
|
|
for(i = 0; i < WEPKEYSTORE; i++) {
|
|
val *= 0x343fd;
|
|
val += 0x269ec3;
|
|
keys[i] = val >> 16;
|
|
}
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* generate one key from a string using the de facto standard
|
|
*
|
|
* resultant key is stored in
|
|
* one 128 bit key: keys[0-15]
|
|
*
|
|
* (NOTE: I'm not sure why, but it seems that only values 0-12 are used,
|
|
* resulting in 104 bits of keying, not 128)
|
|
*/
|
|
void
|
|
wep_keygen128(char *str, u_char *keys)
|
|
{
|
|
MD5_CTX ctx;
|
|
u_char buf[64];
|
|
int i, j;
|
|
|
|
/* repeat str until buf is full */
|
|
j = 0;
|
|
for(i = 0; i < 64; i++) {
|
|
if(str[j] == 0)
|
|
j = 0;
|
|
buf[i] = str[j++];
|
|
}
|
|
|
|
MD5_Init(&ctx);
|
|
MD5_Update(&ctx, buf, sizeof buf);
|
|
MD5_Final(buf, &ctx);
|
|
|
|
memcpy(keys, buf, WEPKEYSTORE);
|
|
for(i = 0; i < WEPSTRONGKEYSIZE; i++) {
|
|
keys[i] = buf[i];
|
|
}
|
|
for(; i < WEPKEYSTORE; i++) {
|
|
keys[i] = 0;
|
|
}
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* generate four subkeys from a string using the defacto standard
|
|
*
|
|
* resultant keys are stored in
|
|
* four 40 bit keys: keys[0-4], keys[5-9], keys[10-14] and keys[15-20]
|
|
*/
|
|
void
|
|
wep_keygen40(char *str, u_char *keys)
|
|
{
|
|
int val, i, shift;
|
|
|
|
/*
|
|
* seed is generated by xor'ing in the keystring bytes
|
|
* into the four bytes of the seed, starting at the little end
|
|
*/
|
|
val = 0;
|
|
for(i = 0; str[i]; i++) {
|
|
shift = i & 0x3;
|
|
val ^= (str[i] << (shift * 8));
|
|
}
|
|
|
|
wep_seedkeygen(val, keys);
|
|
return;
|
|
}
|
|
|
|
void
|
|
wep_keyprint(u_char *keys)
|
|
{
|
|
int i;
|
|
char sepchar;
|
|
|
|
for(i = 0; i < WEPKEYSTORE; i++) {
|
|
sepchar = (i % WEPKEYSIZE == WEPKEYSIZE - 1) ? '\n' : ':';
|
|
printf("%02x%c", keys[i], sepchar);
|
|
}
|
|
return;
|
|
}
|
|
|
|
void
|
|
usage(char *prog)
|
|
{
|
|
printf("Usage: %s [-s] keystring\n", prog);
|
|
exit(1);
|
|
}
|
|
|
|
int
|
|
main(int argc, char **argv)
|
|
{
|
|
u_char keys[WEPKEYSTORE];
|
|
char *prog, *genstr;
|
|
int strong, ch;
|
|
|
|
prog = argv[0];
|
|
strong = 0;
|
|
while((ch = getopt(argc, argv, "s")) != EOF) {
|
|
switch(ch) {
|
|
case 's':
|
|
strong ++;
|
|
break;
|
|
default:
|
|
usage(prog);
|
|
}
|
|
}
|
|
argc -= optind;
|
|
argv += optind;
|
|
|
|
if(argc != 1)
|
|
usage(prog);
|
|
genstr = argv[0];
|
|
|
|
if(strong)
|
|
wep_keygen128(genstr, keys);
|
|
else
|
|
wep_keygen40(genstr, keys);
|
|
|
|
wep_keyprint(keys);
|
|
return 0;
|
|
}
|