void HPRC4LikeCipher::Init(const uint8 *key, uint32 size)
{
// align key to 32 bits
std::vector<uint32> keycopy((size + sizeof(uint32) - 1) / sizeof(uint32));
DEBUG(ASSERT(keycopy.size() * sizeof(uint32) >= size));
// the last 3 bytes may be incomplete, null those before copying
keycopy[keycopy.size() - 1] = 0;
memcpy(&keycopy[0], key, size);
#if IS_BIG_ENDIAN
for(uint32 i = 0; i < keycopy.size(); ++i)
ToLittleEndian(keycopy[i]);
#endif
MTRand mt;
mt.seed((uint32*)&keycopy[0], keycopy.size());
for(uint32 i = 0; i < 256; ++i)
_sbox[i] = i | (mt.randInt() << 8); // lowest bit is always the exchange index, like in original RC4
uint32 a = 0, b = 0;
for(uint32 i = 0; i < std::max<uint32>(256, size); ++i)
{
b += key[a] + _sbox[i & 0xFF];
iswap(_sbox[i & 0xFF], _sbox[b & 0xFF]);
++a;
a %= size;
}
}
bool check_scrabble_found(const std::string& searchkey,
const std::string& match, int jokers)
{
const char* mc = match.data();
int len = match.size();
std::string keycopy(searchkey);
while(len--) {
size_t pos = keycopy.find(*mc);
if (pos == std::string::npos) {
if (--jokers < 0) {
std::cout << "SCRABBLE(" << jokers << "): " << match << " not found with " << searchkey << "\n";
return false;
}
}
else
keycopy.erase(pos, 1);
++mc;
}
return true;
}
