public function createBitArrayObj()
{
$self = $this;
$Bitarray = new BitArray();
$Bitarray->addList($self);
return $Bitarray;
}
/**
* A fast method to retrieve one row of data from the matrix as a BitArray.
*
* @param $y; The row to retrieve
* @param $row; An optional caller-allocated BitArray, will be allocated if null or too small
* @return The resulting BitArray - this reference should always be used even when passing
* your own row
*/
public function getRow($y, $row)
{
if ($row == null || $row->getSize() < $this->width) {
$row = new BitArray($this->width);
} else {
$row->clear();
}
$offset = $y * $this->rowSize;
for ($x = 0; $x < $this->rowSize; $x++) {
$row->setBulk($x * 32, $this->bits[$offset + $x]);
}
return $row;
}
public function merge(BitArray $bitArray2)
{
return new self(array_merge($this->bits, $bitArray2->toArray()));
}
/**
* Convert a list of words to a byte string
* that has the same binary representation with a checksum
* @param array $words
* @return string
*/
public function toEntropy(array $words)
{
// collect up words, compact into bit array
$tmp = new BitArray([]);
for ($i = 0; $i < count($words); $i++) {
$wordIndex = array_search($words[$i], $this->words);
for ($j = 0; $j < 11; $j++) {
$tmp[$i * 11 + $j] = ($wordIndex & 1 << 10 - $j) != 0;
}
}
$concatLenBits = count($tmp);
$checksumLengthBits = $concatLenBits / 33;
$entropyLengthBits = $concatLenBits - $checksumLengthBits;
$entropy = $tmp->slice(0, $entropyLengthBits)->toBytes();
$hashBits = new BitArray(hash("sha256", $entropy, true));
$checksum = $tmp->slice($entropyLengthBits, $checksumLengthBits);
if ($checksum != $hashBits->slice(0, $checksumLengthBits)) {
throw new \RuntimeException("Invalid checksum");
}
return $entropy;
}
