Exchange - validateOrderParam does not check against SUPPORTED_ORDER_VERSION
`validateOrderParam` verifies the signature and version of a provided order. Instead of checking against the contract constant `SUPPORTED_ORDER_VERSION` it, however, checks against a hardcoded version `2` in the method itself.\\nThis might be a problem if `SUPPORTED_ORDER_VERSION` is seen as the configuration parameter for the allowed version. Changing it would not change the allowed order version for `validateOrderParam` as this constant literal is never used.\\nAt the time of this audit, however, the `SUPPORTED_ORDER_VERSION` value equals the hardcoded value in the `validateOrderParam` method.\\n```\\nfunction validateOrderParam(IPerpetual perpetual, LibOrder.OrderParam memory orderParam)\\n    internal\\n    view\\n    returns (bytes32)\\n{\\n    address broker = perpetual.currentBroker(orderParam.trader);\\n    require(broker == msg.sender, "invalid broker");\\n    require(orderParam.getOrderVersion() == 2, "unsupported version");\\n    require(orderParam.getExpiredAt() >= block.timestamp, "order expired");\\n\\n    bytes32 orderHash = orderParam.getOrderHash(address(perpetual), broker);\\n    require(orderParam.signature.isValidSignature(orderHash, orderParam.trader), "invalid signature");\\n    require(filled[orderHash] < orderParam.amount, "fullfilled order");\\n\\n    return orderHash;\\n}\\n```\\n
Check against `SUPPORTED_ORDER_VERSION` instead of the hardcoded value `2`.
```\\nfunction validateOrderParam(IPerpetual perpetual, LibOrder.OrderParam memory orderParam)\\n    internal\\n    view\\n    returns (bytes32)\\n{\\n    address broker = perpetual.currentBroker(orderParam.trader);\\n    require(broker == msg.sender, "invalid broker");\\n    require(orderParam.getOrderVersion() == 2, "unsupported version");\\n    require(orderParam.getExpiredAt() >= block.timestamp, "order expired");\\n\\n    bytes32 orderHash = orderParam.getOrderHash(address(perpetual), broker);\\n    require(orderParam.signature.isValidSignature(orderHash, orderParam.trader), "invalid signature");\\n    require(filled[orderHash] < orderParam.amount, "fullfilled order");\\n\\n    return orderHash;\\n}\\n```\\n