void mod_crypto::fullRC4(BYTE * data, SIZE_T data_len, const BYTE * key, SIZE_T keylen) // pour les clés >= 128 bits (16 octets)
{
ULONG i, j, k = 0, kpos = 0;
BYTE S[256], *pos = data;
for (i = 0; i < 256; i++)
S[i] = static_cast<BYTE>(i);
for (i = 0, j = 0; i < 256; i++)
{
j = (j + S[i] + key[kpos]) & 0xff;
kpos++;
if (kpos >= keylen)
kpos = 0;
S_SWAP(i, j);
}
for (i = 0, j = 0; k < data_len; k++)
{
i = (i + 1) & 0xff;
j = (j + S[i]) & 0xff;
S_SWAP(i, j);
*pos++ ^= S[(S[i] + S[j]) & 0xff];
}
}
void wep_crypt(u8 *key, u8 *buf, size_t plen)
{
u32 i, j, k;
u8 S[256];
#define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
u8 *pos;
/* Setup RC4 state */
for (i = 0; i < 256; i++)
S[i] = i;
j = 0;
for (i = 0; i < 256; i++) {
j = (j + S[i] + key[i & 0x0f]) & 0xff;
S_SWAP(i, j);
}
/* Apply RC4 to data */
pos = buf;
i = j = 0;
for (k = 0; k < plen; k++) {
i = (i + 1) & 0xff;
j = (j + S[i]) & 0xff;
S_SWAP(i, j);
*pos ^= S[(S[i] + S[j]) & 0xff];
pos++;
}
}
void rc4(u8 *buf, size_t len, u8 *key, size_t key_len)
{
u8 S[256];
u32 i, j, k;
u8 kpos, *pos;
/* Setup RC4 state */
for (i = 0; i < 256; i++)
S[i] = i;
j = 0;
kpos = 0;
for (i = 0; i < 256; i++) {
j = (j + S[i] + key[kpos]) & 0xff;
kpos++;
if (kpos >= key_len)
kpos = 0;
S_SWAP(i, j);
}
/* Apply RC4 to data */
pos = buf;
i = j = 0;
for (k = 0; k < len; k++) {
i = (i + 1) & 0xff;
j = (j + S[i]) & 0xff;
S_SWAP(i, j);
*pos++ ^= S[(S[i] + S[j]) & 0xff];
}
}
int
rc4_skip(const u8 *key, size_t keylen, size_t skip,
u8 *data, size_t data_len)
{
u32 i, j, k;
u8 S[256], *pos;
size_t kpos;
/* Setup RC4 state */
for (i = 0; i < 256; i++)
S[i] = i;
j = 0;
kpos = 0;
for (i = 0; i < 256; i++) {
j = (j + S[i] + key[kpos]) & 0xff;
kpos++;
if (kpos >= keylen)
kpos = 0;
S_SWAP(i, j);
}
/* Skip the start of the stream */
i = j = 0;
for (k = 0; k < skip; k++) {
i = (i + 1) & 0xff;
j = (j + S[i]) & 0xff;
S_SWAP(i, j);
}
/* Apply RC4 to data */
pos = data;
for (k = 0; k < data_len; k++) {
i = (i + 1) & 0xff;
j = (j + S[i]) & 0xff;
S_SWAP(i, j);
*pos++ ^= S[(S[i] + S[j]) & 0xff];
}
return 0;
}
void EncryptGrpKey(UINT8 *Encr_Key, UINT8 *IV, UINT8 *Data, UINT16 data_length)
{
/* Setup RC4 state */
UINT32 i, j, k;
UINT8 kpos, key[32];
memcpy(key, IV, 16);
memcpy(key + 16, Encr_Key, 16);
for (i = 0; i < 256; i++)
S[i] = i;
j = 0;
kpos = 0;
for (i = 0; i < 256; i++)
{
j = (j + S[i] + key[kpos]) & 0xff;
kpos++;
if (kpos >= sizeof(key))
kpos = 0;
S_SWAP(i, j);
}
i = j = 0;
//Discard the first 256 bytes
for (k = 0; k < 256; k++)
{
i = (i + 1) & 0xff;
j = (j + S[i]) & 0xff;
S_SWAP(i, j);
}
for (k = 0; k < data_length; k++)
{
i = (i + 1) & 0xff;
j = (j + S[i]) & 0xff;
S_SWAP(i, j);
*Data++ ^= S[(S[i] + S[j]) & 0xff];
}
}
