Differential D17630 Diff 42415 src/infrastructure/util/PhabricatorHash.php

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src/infrastructure/util/PhabricatorHash.php

Show First 20 Lines • Show All 133 Lines • ▼ Show 20 Lines	public static function digestToLength($string, $length) {

$hash = self::digestForIndex($string);		$hash = self::digestForIndex($string);

$prefix = substr($string, 0, ($length - ($min_length - 1)));		$prefix = substr($string, 0, ($length - ($min_length - 1)));

return $prefix.'-'.$hash;		return $prefix.'-'.$hash;
}		}

		public static function digestWithNamedKey($message, $key_name) {
		$key_bytes = self::getNamedHMACKey($key_name);
		return self::digestHMACSHA256($message, $key_bytes);
		}

		public static function digestHMACSHA256($message, $key) {
		if (!strlen($key)) {
		throw new Exception(
		pht('HMAC-SHA256 requires a nonempty key.'));
		}

		$result = hash_hmac('sha256', $message, $key, $raw_output = false);

		if ($result === false) {
		throw new Exception(
		pht('Unable to compute HMAC-SHA256 digest of message.'));
		}

		return $result;
		}


		/* -( HMAC Key Management )------------------------------------------------ */


		private static function getNamedHMACKey($hmac_name) {
		$cache = PhabricatorCaches::getImmutableCache();

		$cache_key = "hmac.key({$hmac_name})";

		$hmac_key = $cache->getKey($cache_key);
		if (!strlen($hmac_key)) {
		$hmac_key = self::readHMACKey($hmac_name);

		if ($hmac_key === null) {
		$hmac_key = self::newHMACKey($hmac_name);
		self::writeHMACKey($hmac_name, $hmac_key);
		}

		$cache->setKey($cache_key, $hmac_key);
		}

		// The "hex2bin()" function doesn't exist until PHP 5.4.0 so just
		// implement it inline.
		$result = '';
		for ($ii = 0; $ii < strlen($hmac_key); $ii += 2) {
		$result .= pack('H*', substr($hmac_key, $ii, 2));
		}

		return $result;
		}

		private static function newHMACKey($hmac_name) {
		$hmac_key = Filesystem::readRandomBytes(64);
		return bin2hex($hmac_key);
		}

		private static function writeHMACKey($hmac_name, $hmac_key) {
		$unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();

		id(new PhabricatorAuthHMACKey())
		->setKeyName($hmac_name)
		->setKeyValue($hmac_key)
		->save();

		unset($unguarded);
		}

		private static function readHMACKey($hmac_name) {
		$table = new PhabricatorAuthHMACKey();
		$conn = $table->establishConnection('r');

		$row = queryfx_one(
		$conn,
		'SELECT keyValue FROM %T WHERE keyName = %s',
		$table->getTableName(),
		$hmac_name);
		if (!$row) {
		return null;
		}

		return $row['keyValue'];
		}


}		}