function mix($a, $b, $c)
{
$a -= $b;
$a -= $c;
$a ^= zeroFill($c, 13);
$b -= $c;
$b -= $a;
$b ^= $a << 8;
$c -= $a;
$c -= $b;
$c ^= zeroFill($b, 13);
$a -= $b;
$a -= $c;
$a ^= zeroFill($c, 12);
$b -= $c;
$b -= $a;
$b ^= $a << 16;
$c -= $a;
$c -= $b;
$c ^= zeroFill($b, 5);
$a -= $b;
$a -= $c;
$a ^= zeroFill($c, 3);
$b -= $c;
$b -= $a;
$b ^= $a << 10;
$c -= $a;
$c -= $b;
$c ^= zeroFill($b, 15);
return array($a, $b, $c);
}
function crunch($arg1, $arg2)
{
$local4 = strlen($arg2);
while ($local5 < $local4) {
$local3 = ord(substr($arg2, $local5));
$arg1 = $arg1 ^ $local3;
$local3 = $local3 % 32;
$arg1 = $arg1 << $local3 & 0xffffffff | zeroFill($arg1, 32 - $local3);
$local5++;
}
return $arg1;
}
function rol($num, $cnt)
{
return $num << $cnt | zeroFill($num, 32 - $cnt);
}
function AESDecryptCtr($ciphertext, $password, $nBits)
{
if (!($nBits == 128 || $nBits == 192 || $nBits == 256)) {
return '';
// standard allows 128/192/256 bit keys
}
$nBytes = $nBits / 8;
// no bytes in key
setLength($pwBytes, $nBytes);
for ($i = 0; $i < $nBytes; $i++) {
$pwBytes[$i] = ord($password[$i]) & 0xff;
}
$pwKeySchedule = KeyExpansion($pwBytes);
$key = Cipher($pwBytes, $pwKeySchedule);
$key = array_merge($key, array_slice($key, 0, $nBytes - 16));
// key is now 16/24/32 bytes long
$keySchedule = KeyExpansion($key);
$ciphertext = explode('-', $ciphertext);
// split ciphertext into array of block-length strings
// recover nonce from 1st element of ciphertext
$blockSize = 16;
// block size fixed at 16 bytes / 128 bits (Nb=4) for AES
setLength($counterBlock, $blockSize);
$ctrTxt = unescCtrlChars($ciphertext[0]);
for ($i = 0; $i < 8; $i++) {
$counterBlock[$i] = ord($ctrTxt[$i]);
}
setLength($plaintext, count($ciphertext) - 1);
for ($b = 1; $b < count($ciphertext); $b++) {
// set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
for ($c = 0; $c < 4; $c++) {
$counterBlock[15 - $c] = zeroFill($b - 1, $c * 8) & 0xff;
}
for ($c = 0; $c < 4; $c++) {
$counterBlock[15 - $c - 4] = zeroFill($b / 0x100000000 - 1, $c * 8) & 0xff;
}
$cipherCntr = Cipher($counterBlock, $keySchedule);
// encrypt counter block
$ciphertext[$b] = unescCtrlChars($ciphertext[$b]);
$pt = '';
for ($i = 0; $i < strlen($ciphertext[$b]); $i++) {
// -- xor plaintext with ciphered counter byte-by-byte --
$ciphertextByte = ord($ciphertext[$b][$i]);
$plaintextByte = $ciphertextByte ^ $cipherCntr[$i];
$pt .= chr($plaintextByte);
}
// pt is now plaintext for this block
$plaintext[$b - 1] = $pt;
// b-1 'cos no initial nonce block in plaintext
}
return implode('', $plaintext);
}
