Tracking::parseSignedTag

static function parseSignedTag($signedTag)
{
	try
	{
		$signer = new Signer;
		$unsignedTag = $signer->unsign($signedTag, static::SIGN_SALT_ACTION);
		return static::parseTag($unsignedTag);
	}
	catch (BadSignatureException $e)
	{
	}

	$signer->setKey(self::getSignKey());
	$unsignedTag = $signer->unsign($signedTag, static::SIGN_SALT_ACTION);
	return static::parseTag($unsignedTag);
}