- Код: Выделить всё
/* thanks to RElf (spam4relf@chat.ru) */
#include <stdio.h>
#include <string.h>
#include "Getkeys.h"
/* Load long from address C into LL with bytes swapped. */
#define N2L(C, LL) \
LL = ((unsigned int)(*((C)++))) << 24, \
LL |= ((unsigned int)(*((C)++))) << 16, \
LL |= ((unsigned int)(*((C)++))) << 8, \
LL |= ((unsigned int)(*((C)++)))
/* we need less than 32 bytes to get k0, but we need at least 40 bytes to get k1... */
#define SIZE 62
static unsigned int key0[62+1];
static unsigned int key1[62+1];
static unsigned int k0=0;
static unsigned int k1=0;
static unsigned int k30=0; /* would be (L_{31}(k0) shr 1) ^ L_{30}(k0). */
static void init(unsigned char * pseed)
{
unsigned int seed;
N2L(pseed, seed);
key0[0] =
(((~seed) ^ 0x00001357) << 16)
| ((seed ^ 0xffffaaaa) & 0x0000ffff);
key1[0] =
((seed ^ 0x43210000) >> 16)
| (((~seed) ^ 0xabcdffff) & 0xffff0000);
}
static void crypt(unsigned char *buff, int len)
{
int i = 0;
int m_key0 = key0[0];
int m_key1 = key1[0];
unsigned int table0 = 0, table1 = 0;
for(i = 0; i < len; i++)
{
buff[i] = buff[i] ^ (unsigned char)m_key0;
table0 = m_key0;
table1 = m_key1;
m_key0 = ((table0 >> 1) | (table1 << 31)) ^ k1;
table1 = ((table1 >> 1) | (table0 << 31));
m_key1 = ((table1 >> 1) | (table0 << 31)) ^ k30;
}
return;
}
/* low a bits of b */
#define L(a,b) ((b) & (((__int64)1<<((a)+1))-1))
/* a-st bit of b */
#define B(a,b) (((b) >> (a)) & 1)
/*
* everything goes from these formulas:
* key1[n+1] = ((( ((key1[n]>>1) ^ (key0[n]<<31)) ^ k0)>>1 )) ^ (key0[n]<<31) ) ^ k0;
* key0[n+1] = ((key0[n]>>1) ^ (key1[n]<<31)) ^ k1;
*/
int CalculateKeys(unsigned char Plaintext[62], unsigned char Ciphertext[62], unsigned int *LoginSeed,
unsigned int *ClientLoginKey1, unsigned int *ClientLoginKey2)
{
int i = 0, t = 0, n = 0;
/* clean the vars */
memset(key0, 0, sizeof(key0));
memset(key1, 0, sizeof(key1));
k0 = k1 = k30 = 0;
/* fill key0[] array with known bits: */
for(i = 0; i < SIZE; i++)
key0[i] = Plaintext[i] ^ Ciphertext[i];
/* calculate key0[0] & key1[0] */
init((unsigned char*)LoginSeed);
/* Get first 8 bits of k1: */
k1 = B(8, (key0[1] ^ ((key0[0]>>1) | (key1[0]<<31))));
/*
* use formula to calculate remaining bits of k1/key0[n]:
* L_{t+1}(key0[n]) = ((L_t(key0[n+1])^L_t(k1)) shl 1) | B_0(key0[n]);
*/
for(t = 7; t < 32; t++)
{
for(n = 1; n < SIZE; n++)
key0[n] = L(t+1, ( ((L(t,key0[n+1]) ^ L(t,k1))<<1) ) | (B(0,key0[n])) );
k1 = L(t+1, (key0[1] ^ ((key0[0]>>1) | (key1[0]<<31))) );
}
*ClientLoginKey2 = k1;
/* CALCULATE k30 */
/*
* Calculate 1st bits of key1[n]:
* B_0(key1[n]) = (key0[n+1]^k1) shr 31;
*/
k30 = 0;
for(n=1; n<SIZE; n++)
key1[n] = B(31, key0[n+1] ^ k1 );
/*
* calculate remaining bits of key1:
* B_t(key1[n+1]) = B_{t+2}(key1[n]) ^ B_t(k30)
* B_{t+2}(key1[n]) = B_t(key1[n+1]) ^ B_t(k30)
* B_t(k30) = B_{t+2}(key1[n]) ^ B_t(key1[n+1])
*/
k30=0;
for(t = 0; t < 30; t+=2)
{
k30 |= (B(t+2, key1[0]) ^ B(t, key1[1])) << t;
/* calculate t+2 bits */
for(n = 1; n < SIZE; n++)
key1[n] |= (B(t, key1[n+1]) ^ B(t, k30)) << (t+2);
}
/*
* B_31(key1[n+1])=B_30(key1[n+1])
* key1[1]|=B(30,key1[1])<<31;
*/
/* get 31st bit of k. By the way, it is == bit 30 */
k30 |= (B(30, key1[1]) ^ L(1,key0[0])) << 31;
/* encrypt and see if it worked */
*ClientLoginKey1 = k30;
crypt(Plaintext, SIZE);
if(memcmp(Ciphertext, Plaintext, SIZE) != 0)
return -1; /* if not, oops */
return 1;
}
Функция CalculateKeys написаная на си отвечает за доставание 2 ключей из масива для дальнейшей расшифровки пакетов ultima online. Плиз переведите етот код на родной VB или хотябы обясните что ето за корявый синтаксис "^","<<",">>","~","|" ? ...
Ато я не вчехлил что такое побитовое смещение.
