Merge pull request #2 from InstaDApp/fix-pausable

fixed ERC20Pausable and added ReentrancyGuard

contracts/deployer.sol

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.6.8;
 
 interface IProxy {

contracts/ethPool.sol

@@ -2,13 +2,12 @@
 pragma solidity ^0.6.8;
 pragma experimental ABIEncoderV2;
 
-import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/ERC20Pausable.sol";
+import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
 
 import { DSMath } from "./libs/safeMath.sol";
 
-// TODO - Add ReentrancyGuard lib
-
 interface AccountInterface {
   function enable(address authority) external;
   function cast(address[] calldata _targets, bytes[] calldata _datas, address _origin) external payable;
@@ -30,7 +29,7 @@ interface RateInterface {
   function getTotalToken() external returns (uint totalUnderlyingTkn);
 }
 
-contract PoolToken is ERC20, DSMath {
+contract PoolToken is ReentrancyGuard, ERC20Pausable, DSMath {
   event LogDeploy(uint amount);
   event LogExchangeRate(uint exchangeRate, uint tokenBalance, uint insuranceAmt);
   event LogSettle(uint settleTime);
@@ -39,16 +38,14 @@ contract PoolToken is ERC20, DSMath {
   event LogAddInsurance(uint amount);
   event LogPausePool(bool);
 
-    // IERC20 public immutable baseToken;
   RegistryInterface public immutable registry; // Pool Registry
   IndexInterface public constant instaIndex = IndexInterface(0x2971AdFa57b20E5a416aE5a708A8655A9c74f723);
   AccountInterface public immutable dsa; // Pool's DSA account
 
-    IERC20 public immutable baseToken; // Base token. Eg:- DAI, USDC, etc.
+  IERC20 public immutable baseToken; // Base token.
   uint private tokenBalance; // total token balance since last rebalancing
   uint public exchangeRate = 10 ** 18; // initial 1 token = 1
   uint public insuranceAmt; // insurance amount to keep pool safe
-    bool public pausePool; // shutdown deposits and withdrawals
 
   constructor(
     address _registry,
@@ -103,8 +100,7 @@ contract PoolToken is ERC20, DSMath {
     emit LogSettle(block.timestamp);
   }
 
-    function deposit(uint tknAmt) public payable returns(uint) {
+  function deposit(uint tknAmt) public whenNotPaused payable returns(uint) {
-        require(!pausePool, "pool-shut");
     require(tknAmt == msg.value, "unmatched-amount");
     uint _newTokenBal = add(tokenBalance, msg.value);
     require(_newTokenBal <= registry.poolCap(address(this)), "deposit-cap-reached");
@@ -115,8 +111,7 @@ contract PoolToken is ERC20, DSMath {
     emit LogDeposit(tknAmt, _mintAmt);
   }
 
-    function withdraw(uint tknAmt, address to) external returns (uint _tknAmt) {
+  function withdraw(uint tknAmt, address to) external nonReentrant whenNotPaused returns (uint _tknAmt) {
-        require(!pausePool, "pool-shut");
     uint poolBal = address(this).balance;
     require(tknAmt <= poolBal, "not-enough-liquidity-available");
     uint _bal = balanceOf(msg.sender);
@@ -133,7 +128,7 @@ contract PoolToken is ERC20, DSMath {
 
     _burn(msg.sender, _burnAmt);
 
-        payable(to).transfer(_tknAmt); // TODO - if this is also Reentrancy prone attack or not.
+    payable(to).transfer(_tknAmt);
 
     emit LogWithdraw(tknAmt, _burnAmt);
   }
@@ -146,8 +141,7 @@ contract PoolToken is ERC20, DSMath {
 
   function shutdown() external {
     require(msg.sender == instaIndex.master(), "not-master");
-        pausePool = !pausePool;
+    paused() ? _unpause() : _pause();
-        emit LogPausePool(pausePool);
   }
 
   receive() external payable {}

contracts/flusher.sol

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.6.8;
 pragma experimental ABIEncoderV2;
 

contracts/tokenPool.sol

@@ -2,9 +2,9 @@
 pragma solidity ^0.6.8;
 pragma experimental ABIEncoderV2;
 
-import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/ERC20Pausable.sol";
+import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
 
 import { DSMath } from "./libs/safeMath.sol";
 
@@ -29,7 +29,7 @@ interface RateInterface {
   function getTotalToken() external returns (uint totalUnderlyingTkn);
 }
 
-contract PoolToken is DSMath, ERC20, ERC20Pausable {
+contract PoolToken is ReentrancyGuard, DSMath, ERC20Pausable {
     using SafeERC20 for IERC20;
 
     event LogDeploy(uint amount);
@@ -48,7 +48,6 @@ contract PoolToken is DSMath, ERC20, ERC20Pausable {
     uint private tokenBalance; // total token balance since last rebalancing
     uint public exchangeRate = 10 ** 18; // initial 1 token = 1
     uint public insuranceAmt; // insurance amount to keep pool safe
-    bool public pausePool; // shutdown deposits and withdrawals
 
     constructor(
         address _registry,
@@ -102,8 +101,7 @@ contract PoolToken is DSMath, ERC20, ERC20Pausable {
       emit LogSettle(block.timestamp);
     }
 
-    function deposit(uint tknAmt) external payable returns(uint) {
+    function deposit(uint tknAmt) external whenNotPaused payable returns(uint) {
-        require(!pausePool, "pool-shut");
       uint _newTokenBal = add(tokenBalance, tknAmt);
       require(_newTokenBal <= registry.poolCap(address(this)), "deposit-cap-reached");
 
@@ -114,8 +112,7 @@ contract PoolToken is DSMath, ERC20, ERC20Pausable {
       emit LogDeposit(tknAmt, _mintAmt);
     }
 
-    function withdraw(uint tknAmt, address to) external returns (uint _tknAmt) {
+    function withdraw(uint tknAmt, address to) external nonReentrant whenNotPaused returns (uint _tknAmt) {
-        require(!pausePool, "pool-shut");
       uint poolBal = baseToken.balanceOf(address(this));
       require(tknAmt <= poolBal, "not-enough-liquidity-available");
       uint _bal = balanceOf(msg.sender);