/**
* @param \ParagonIE\AsgardClient\Structures\MerkleTree $tree
* @param string $prevhash
* @param string $nexthash
*/
public function __construct(MerkleTree $tree, $prevhash = null, $nexthash = null)
{
$this->merkleTree = $tree;
$this->currentHash = $tree->getRoot();
$this->previousHash = $prevhash;
$this->nextHash = $nexthash;
if (empty($prevhash)) {
$this->tailHash = $this->currentHash;
} else {
$this->tailHash = \Sodium::crypto_generichash(\bin2hex($this->previousHash) . \bin2hex($this->currentHash));
}
}
/**
* Verify the checksums on $tmp_file for the package we are verifying
*
* @param array $blockdata
* @param string $tmp_file
* @return boolean
*/
private function verifyChecksums($blockdata, $tmp_file)
{
$matches = 0;
$filedata = \file_get_contents($tmp_file);
// Now let's check all of the hashes
foreach ($blockdata['checksums'] as $algo => $hash) {
switch ($algo) {
case 'BLAKE2b':
// We used libsodium
$line = \Sodium::crypto_generichash($filedata);
break;
default:
// A simple hash (SHA256, etc)
$line = \hash($algo, $filedata, true);
}
if (\hash_equals($line, \Sodium::sodium_hex2bin($hash))) {
++$matches;
} else {
die("{$algo} hash did not match!");
}
}
unset($filedata);
// explicitly free
return $matches > 0;
}
/**
* Calculate the hash tree for a given dataset:
* 0 => Merkle Root
* 1 => Left Child
* 2 => Right Child,
* 3 => LL, 4 => LR
* 5 => RL, 6 => RR,
* ...
*
* @return array
*/
public function getTree()
{
$numLeaves = count($this->leaves);
// get the next 2^N larger than our dataset
$baseIterate = (int) pow(2, ceil(log($numLeaves, 2)));
$hashes = [];
// Initial population
for ($i = 0; $i < $baseIterate; ++$i) {
if ($i >= $numLeaves) {
// Following Bitcoin's lead; keep hashing the remainder
$hashes[] = $this->leaves[$numLeaves - 1]['hash'];
} else {
$hashes[] = $this->leaves[$i]['hash'];
}
}
$tree = $hashes;
// Let's hash together until we have one node left
do {
$tmp = [];
// Iterate through the first level of the tree
$j = 0;
for ($i = 0; $i < $baseIterate; $i += 2) {
$tmp[$j] = \Sodium::crypto_generichash($hashes[$i] . $hashes[$i + 1]);
\array_unshift($tree, $tmp[$j]);
++$j;
}
$hashes = $tmp;
$baseIterate = $baseIterate >> 1;
} while ($baseIterate > 1);
return $tree;
}
