Add TokenMinter contract

README.md

@@ -101,6 +101,8 @@ _Note: The following descriptions are for AuRa contracts only. HBBFT contract im
   - withdrawing tokens and rewards by participants from the pools;
   - moving tokens between pools by participant.
 
+- `TokenMinter`: used when we need to have an ability to mint POSDAO tokens not only by the bridge, but also by the `BlockRewardAuRa` contract if the staking token contract doesn't support a `mintReward` function.
+
 - `TxPermission`: along with the `Certifier` contract, controls the use of zero gas price by validators in service transactions, protecting the network against "transaction spamming" by malicious validators. The protection logic is declared in the `allowedTxTypes` function.
 
 - `TxPriority`: manages and stores the transactions priority list used by Ethereum client. See https://github.com/NethermindEth/nethermind/issues/2300 for description.

contracts/TokenMinter.sol

@@ -0,0 +1,72 @@
+pragma solidity 0.5.10;
+
+
+interface IToken {
+    function claimTokens(address _token, address payable _to) external;
+    function mint(address _to, uint256 _amount) external returns (bool);
+    function transferOwnership(address _newOwner) external;
+}
+
+
+/// @dev Used when we need to have an ability to mint POSDAO tokens not only by the bridge,
+/// but also by the BlockRewardAuRa contract if the staking token contract doesn't support
+/// the `mintReward` function.
+contract TokenMinter {
+
+    address public blockRewardContract;
+    address public bridgeContract;
+    IToken public tokenContract;
+
+    modifier onlyBlockRewardContract() {
+        require(msg.sender == blockRewardContract);
+        _;
+    }
+
+    modifier onlyBridgeContract() {
+        require(msg.sender == bridgeContract);
+        _;
+    }
+
+    constructor(address _blockRewardContract, address _bridgeContract, IToken _tokenContract) public {
+        require(_isContract(_blockRewardContract));
+        require(_isContract(_bridgeContract));
+        require(_isContract(address(_tokenContract)));
+        blockRewardContract = _blockRewardContract;
+        bridgeContract = _bridgeContract;
+        tokenContract = _tokenContract;
+    }
+
+    function claimTokens(address _token, address payable _to) public onlyBridgeContract {
+        tokenContract.claimTokens(_token, _to);
+    }
+
+    function mint(address _to, uint256 _amount) external onlyBridgeContract returns (bool) {
+        return tokenContract.mint(_to, _amount);
+    }
+
+    function mintReward(uint256 _amount) external onlyBlockRewardContract {
+        if (_amount == 0) return;
+        tokenContract.mint(blockRewardContract, _amount);
+    }
+
+    function setBlockRewardContract(address _blockRewardContract) external onlyBridgeContract {
+        require(_isContract(_blockRewardContract));
+        blockRewardContract = _blockRewardContract;
+    }
+
+    function setBridgeContract(address _bridgeContract) external onlyBridgeContract {
+        require(_isContract(_bridgeContract));
+        bridgeContract = _bridgeContract;
+    }
+
+    function transferOwnership(address _newOwner) external onlyBridgeContract {
+        tokenContract.transferOwnership(_newOwner);
+    }
+
+    function _isContract(address _account) private view returns (bool) {
+        uint256 size;
+        assembly { size := extcodesize(_account) }
+        return size > 0;
+    }
+
+}

contracts/base/BlockRewardAuRaTokens.sol

@@ -249,13 +249,16 @@ contract BlockRewardAuRaTokens is BlockRewardAuRaBase, IBlockRewardAuRaTokens {
 
         bridgeTokenReward = 0;
 
+        IERC677 tokenContract = IERC677(IStakingAuRaTokens(_stakingContract).erc677TokenContract());
         ITokenMinter minterContract;
-        if (tokenMinterContract == ITokenMinter(0)) {
-            minterContract = ITokenMinter(
-                IStakingAuRaTokens(_stakingContract).erc677TokenContract()
-            );
+        if (tokenMinterContract != ITokenMinter(0) && tokenContract != IERC677(0)) {
+            if (tokenContract.owner() == address(tokenMinterContract)) {
+                minterContract = tokenMinterContract;
+            } else {
+                minterContract = ITokenMinter(0);
+            }
         } else {
-            minterContract = tokenMinterContract;
+            minterContract = ITokenMinter(address(tokenContract));
         }
 
         uint256 distributedAmount = 0;

contracts/interfaces/IERC677.sol

@@ -7,5 +7,6 @@ interface IERC677 {
 
     // Other functions (ERC677)
     function balanceOf(address) external view returns(uint256);
+    function owner() external view returns(address);
     function transfer(address, uint256) external returns(bool);
 }

scripts/get_deploy_estimate_gas.js

@@ -32,7 +32,8 @@ async function main() {
         //contractName.startsWith('ERC677BridgeTokenRewardable') ||
         contractName.startsWith('Initializer') ||
         contractName.startsWith('Migrations') ||
-        contractName.startsWith('Registry')
+        contractName.startsWith('Registry') ||
+        contractName.startsWith('TokenMinter')
       ) {
         continue;
       }