static void rc4(rc4_key* key, unsigned char *buffer_ptr, int buffer_len)
{
unsigned char x;
unsigned char y;
unsigned char* state;
unsigned char xorIndex;
short counter;
x = key->x;
y = key->y;
state = &key->state[0];
for(counter = 0; counter < buffer_len; counter ++)
{
x = (unsigned char)((x + 1) % 256);
y = (unsigned char)((state[x] + y) % 256);
ARES_SWAP_BYTE(&state[x], &state[y]);
xorIndex = (unsigned char)((state[x] + state[y]) % 256);
buffer_ptr[counter] = (unsigned char)(buffer_ptr[counter]^state[xorIndex]);
}
key->x = x;
key->y = y;
}
static int init_id_key(rc4_key* key,int key_data_len)
{
unsigned char index1;
unsigned char index2;
unsigned char* state;
short counter;
unsigned char *key_data_ptr = 0;
key_data_ptr = calloc(1,key_data_len);
if (!key_data_ptr)
return ARES_ENOMEM;
state = &key->state[0];
for(counter = 0; counter < 256; counter++)
/* unnecessary AND but it keeps some compilers happier */
state[counter] = (unsigned char)(counter & 0xff);
randomize_key(key->state,key_data_len);
key->x = 0;
key->y = 0;
index1 = 0;
index2 = 0;
for(counter = 0; counter < 256; counter++)
{
index2 = (unsigned char)((key_data_ptr[index1] + state[counter] +
index2) % 256);
ARES_SWAP_BYTE(&state[counter], &state[index2]);
index1 = (unsigned char)((index1 + 1) % key_data_len);
}
free(key_data_ptr);
return ARES_SUCCESS;
}