Create Governance based bridge contracts

.editorconfig

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+# EditorConfig is awesome: http://EditorConfig.org
+
+root = true
+
+[*]
+end_of_line = lf
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.ts]
+indent_style = tab
+
+[{package.json,.travis.yml}]
+indent_style = space
+indent_size = 4

README.md

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+# Dependencies
+```bash
+npm install
+```
+
+# To Deploy
+Check `truffle.js` for networks and their ports
+```bash
+NETWORK=sokol npm run deploy
+```
+
+# To Flatten
+```bash
+npm run flatten
+```

contracts/BridgeDeploymentAddressStorage.sol

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+pragma solidity ^0.4.19;
+
+
+contract BridgeDeploymentAddressStorage {
+    uint256 public deployedAtBlock;
+
+    function BridgeDeploymentAddressStorage() public {
+        deployedAtBlock = block.number;
+    }
+}

contracts/BridgeValidators.sol

@@ -1,52 +1,58 @@
 pragma solidity ^0.4.18;
 
-import 'zeppelin-solidity/contracts/ownership/Ownable.sol';
-
-contract BridgeValidators is Ownable {
-
-	// Event created on validator gets added
-	event ValidatorAdded (address validator);
-	event ValidatorRemoved (address validator);
-	uint8 requiredValidators = 0;
-	uint256 public validatorCount = 0;
-
-	mapping (address => bool) public validators;
-
-	function BridgeValidators(uint8 _requiredValidators,address[] _initialValidators) public {
-	    require(_requiredValidators != 0);
-	    require(_initialValidators.length >= _requiredValidators);
-	    setRequiredValidators(_requiredValidators);
-	    for (uint i = 0; i < _initialValidators.length; i++) {
-		require(!isValidator(_initialValidators[i]) && _initialValidators[i] != address(0));
-		addValidator(_initialValidators[i]);
-    	    }
-	    validatorCount = _initialValidators.length;
-	}
-
-	function addValidator(address _validator)  public onlyOwner {
-		assert(validators[_validator] != true);
-		validatorCount++;
-		validators[_validator] = true;
-		ValidatorAdded(_validator);
-	}
-
-	function removeValidator(address _validator) public onlyOwner {
-		require(validatorCount > requiredValidators);
-		validators[_validator] = false;
-		validatorCount--;
-		ValidatorRemoved(_validator);
-	}
-
-	function setRequiredValidators(uint8 _requiredValidators) public onlyOwner {
-		require(validatorCount >= _requiredValidators);
-		requiredValidators = _requiredValidators;
-	}
-
-	function isValidator(address _validator) public view returns(bool) {
-		return (validators[_validator] == true);
-	}
-
-	function onlyValidator(address _validator) public view returns(bool) {
-		return validators[_validator] == true;
-	}	
+import "zeppelin-solidity/contracts/ownership/Ownable.sol";
+import "./IBridgeValidators.sol";
+
+
+contract BridgeValidators is Ownable, IBridgeValidators {
+
+  // Event created on validator gets added
+    event ValidatorAdded (address validator);
+    event ValidatorRemoved (address validator);
+    uint8 requiredValidators = 0;
+    uint256 public validatorCount = 0;
+
+    mapping (address => bool) public validators;
+
+    function BridgeValidators(uint8 _requiredValidators, address[] _initialValidators) public Ownable() {
+        require(_requiredValidators != 0);
+        require(_initialValidators.length >= _requiredValidators);
+        validatorCount = _initialValidators.length;
+        for (uint i = 0; i < _initialValidators.length; i++) {
+            require(!isValidator(_initialValidators[i]) && _initialValidators[i] != address(0));
+            addValidator(_initialValidators[i]);
+        }
+        setRequiredValidators(_requiredValidators);
+    }
+
+    function addValidator(address _validator)  public onlyOwner {
+        assert(validators[_validator] != true);
+        validatorCount++;
+        validators[_validator] = true;
+        ValidatorAdded(_validator);
+    }
+
+    function removeValidator(address _validator) public onlyOwner {
+        require(validatorCount > requiredValidators);
+        validators[_validator] = false;
+        validatorCount--;
+        ValidatorRemoved(_validator);
+    }
+
+    function setRequiredValidators(uint8 _requiredValidators) public onlyOwner {
+        require(validatorCount >= _requiredValidators);
+        requiredValidators = _requiredValidators;
+    }
+
+    function isValidator(address _validator) public view returns(bool) {
+        return validators[_validator] == true;
+    }
+
+    function requiredSignatures() public view returns(uint8) {
+        return requiredValidators;
+    }
+
+    function currentOwner() public view returns(address) {
+        return owner;
+    }
 }

contracts/ERC677.sol

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+pragma solidity 0.4.19;
+import "zeppelin-solidity/contracts/token/ERC20/ERC20.sol";
+
+
+contract ERC677 is ERC20 {
+    event Transfer(address indexed from, address indexed to, uint value, bytes data);
+
+    function transferAndCall(address, uint, bytes) public returns (bool);
+
+}

contracts/ERC677Receiver.sol

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+pragma solidity ^0.4.19;
+
+
+contract ERC677Receiver {
+  function onTokenTransfer(address _from, uint _value, bytes _data) external returns(bool);
+}

contracts/ForeignBridge.sol

@@ -1,75 +1,99 @@
 pragma solidity 0.4.19;
+import "./libraries/SafeMath.sol";
 import "./libraries/Helpers.sol";
 import "./libraries/Message.sol";
-import "./libraries/MessageSigning.sol";
-import "./BridgeValidators.sol";
-
-contract ForeignBridge {
+import "./IBridgeValidators.sol";
+import "./Validatable.sol";
+import "./BridgeDeploymentAddressStorage.sol";
+import "./IBurnableMintableERC677Token.sol";
+import "./ERC677Receiver.sol";
+
+contract ForeignBridge is ERC677Receiver, Validatable, BridgeDeploymentAddressStorage {
+    using SafeMath for uint256;
+    uint256 public gasLimitDepositRelay;
+    uint256 public gasLimitWithdrawConfirm;
+    uint256 homeGasPrice = 1000000000 wei;
+    uint256 public foreignDailyLimit;
+    mapping (bytes32 => bytes) messages;
+    mapping (bytes32 => bytes) signatures;
+    mapping (bytes32 => bool) messages_signed;
+    mapping (bytes32 => uint256) num_messages_signed;
     mapping (bytes32 => bool) deposits_signed;
-    mapping (bytes32 => uint8) num_deposits_signed;
-	mapping (bytes32 => bool) mintRequestsDone;
-	mapping (bytes32 => uint8) withdrawRequests;
-
-    /// Pending signatures and authorities who confirmed them
-    BridgeValidators public validatorsContract;
+    mapping (bytes32 => uint256) num_deposits_signed;
+    mapping (uint256 => uint256) totalSpentPerDay;
 
-    /// Token contract which the bridge has full ownership to burn and mint
-    address public token;
+    IBurnableMintableERC677Token public erc677token;
 
     /// triggered when relay of deposit from HomeBridge is complete
     event Deposit(address recipient, uint value);
 
     /// Event created on money withdraw.
-    event Withdraw(address recipient, uint value);
+    event Withdraw(address recipient, uint256 value, uint256 homeGasPrice);
 
     /// Collected signatures which should be relayed to home chain.
     event CollectedSignatures(address authorityResponsibleForRelay, bytes32 messageHash);
 
+    event GasConsumptionLimitsUpdated(uint256 gasLimitDepositRelay, uint256 gasLimitWithdrawConfirm);
+
+    event SignedForDeposit(address indexed signer, bytes32 message);
+    event SignedForWithdraw(address indexed signer, bytes32 message);
+    event DailyLimit(uint256 newLimit);
+
     function ForeignBridge(
-        address _token,
-        address _validatorsContract
-    ) public
-    {
-        require(_token != address(0) && _validatorsContract != address(0));
-        validatorsContract = BridgeValidators(_validatorsContract);
-        token = _token;
+        address _validatorContract,
+        address _erc677token,
+        uint256 _foreignDailyLimit
+    ) public Validatable(_validatorContract) {
+        require(_foreignDailyLimit > 0);
+        erc677token = IBurnableMintableERC677Token(_erc677token);
+        foreignDailyLimit = _foreignDailyLimit;
     }
 
+    function setGasLimitDepositRelay(uint256 _gas) public onlyOwner {
+        gasLimitDepositRelay = _gas;
 
-    /// Used to deposit money to the contract.
-    ///
-    /// deposit recipient (bytes20)
-    /// deposit value (uint)
-    /// mainnet transaction hash (bytes32) // to avoid transaction duplication
-    function deposit(address recipient, uint256 value, bytes32 transactionHash) public {
-        require(validatorsContract.onlyValidator(msg.sender));
+        GasConsumptionLimitsUpdated(gasLimitDepositRelay, gasLimitWithdrawConfirm);
+    }
+
+    function setGasLimitWithdrawConfirm(uint256 gas) public onlyOwner {
+        gasLimitWithdrawConfirm = gas;
+
+        GasConsumptionLimitsUpdated(gasLimitDepositRelay, gasLimitWithdrawConfirm);
+    }
+
+    function deposit(address recipient, uint value, bytes32 transactionHash) public onlyValidator {
+        require(erc677token != address(0x0));
+
+        // Protection from misbehaing authority
         bytes32 hash_msg = keccak256(recipient, value, transactionHash);
         bytes32 hash_sender = keccak256(msg.sender, hash_msg);
 
-        // Prevents Duplicated deposits
+        // Duplicated deposits
         require(!deposits_signed[hash_sender]);
         deposits_signed[hash_sender] = true;
 
-        uint8 signed = num_deposits_signed[hash_msg] + 1;
+        uint256 signed = num_deposits_signed[hash_msg] + 1;
         num_deposits_signed[hash_msg] = signed;
 
-        if (signed == requiredValidators) {
-            // token.mint(recipient, value);
+        SignedForDeposit(msg.sender, transactionHash);
+
+        if (signed == validatorContract.requiredSignatures()) {
+            // If the bridge contract does not own enough tokens to transfer
+            // it will couse funds lock on the home side of the bridge
+            erc677token.mint(recipient, value);
             Deposit(recipient, value);
         }
+
     }
 
-    /// Transfer `value` from `msg.sender`s local balance (on `foreign` chain) to `recipient` on `home` chain.
-    ///
-    /// immediately decreases `msg.sender`s local balance.
-    /// emits a `Withdraw` event which will be picked up by the bridge authorities.
-    /// bridge authorities will then sign off (by calling `submitSignature`) on a message containing `value`,
-    /// `recipient` and the `hash` of the transaction on `foreign` containing the `Withdraw` event.
-    /// once `requiredSignatures` are collected a `CollectedSignatures` event will be emitted.
-    /// an authority will pick up `CollectedSignatures` an call `HomeBridge.withdraw`
-    /// which transfers `value - relayCost` to `recipient` completing the transfer.
-    function transferHomeViaRelay(address recipient, uint256 value) public {
-        Withdraw(recipient, value);
+    function onTokenTransfer(address _from, uint256 _value, bytes _data) external returns(bool) {
+        require(erc677token != address(0x0));
+        require(msg.sender == address(erc677token));
+        require(withinLimit(_value));
+        totalSpentPerDay[getCurrentDay()] = totalSpentPerDay[getCurrentDay()].add(_value);
+        erc677token.burn(_value);
+        Withdraw(_from, _value, homeGasPrice);
+        return true;
     }
 
     /// Should be used as sync tool
@@ -80,34 +104,62 @@ contract ForeignBridge {
     /// withdrawal recipient (bytes20)
     /// withdrawal value (uint)
     /// foreign transaction hash (bytes32) // to avoid transaction duplication
-    function submitSignature(bytes signature, bytes message) public {
-        require(validatorsContract.onlyValidator(msg.sender));
-        // Validate submited signatures
-        require(MessageSigning.recoverAddressFromSignedMessage(signature, message) == msg.sender);
+    function submitSignature(bytes signature, bytes message) public onlyValidator {
+        // ensure that `signature` is really `message` signed by `msg.sender`
+        require(msg.sender == MessageSigning.recoverAddressFromSignedMessage(signature, message));
 
-        // Valid withdraw message must have 84 bytes
-        require(message.length == 84);
-        var hash = keccak256(message);
+        require(message.length == 116);
+        bytes32 hash = keccak256(message);
+        bytes32 hash_sender = keccak256(msg.sender, hash);
 
-        // Duplicated signatures
-        // require(!Helpers.addressArrayContains(signatures[hash].signed, msg.sender));
-        // signatures[hash].message = message;
-        // signatures[hash].signed.push(msg.sender);
-        // signatures[hash].signatures.push(signature);
+        uint signed = num_messages_signed[hash_sender] + 1;
+
+        if (signed > 1) {
+            // Duplicated signatures
+            require(!messages_signed[hash_sender]);
+        }
+        else {
+            // check if it will really reduce gas usage in case of the second transaction
+            // with the same hash
+            messages[hash] = message;
+        }
+        messages_signed[hash_sender] = true;
+
+        bytes32 sign_idx = keccak256(hash, (signed-1));
+        signatures[sign_idx] = signature;
+
+        num_messages_signed[hash_sender] = signed;
 
         // TODO: this may cause troubles if requiredSignatures len is changed
-        // if (signatures[hash].signed.length == requiredSignatures) {
+        SignedForWithdraw(msg.sender, hash);
+        if (signed == validatorContract.requiredSignatures()) {
             CollectedSignatures(msg.sender, hash);
-        // }
+        }
+    }
+
+    function signature(bytes32 hash, uint index) public view returns (bytes) {
+        bytes32 sign_idx = keccak256(hash, index);
+        return signatures[sign_idx];
     }
 
-    /// Get signature
-    // function signature(bytes32 hash, uint index) public view returns (bytes) {
-    //     return signatures[hash].signatures[index];
-    // }
+    /// Get message
+    function message(bytes32 hash) public view returns (bytes) {
+        return messages[hash];
+    }
+
+    function getCurrentDay() public view returns(uint256) {
+        return now / 1 days;
+    }
+
+    function setDailyLimit(uint256 _foreignDailyLimit) public onlyOwner {
+        require(_foreignDailyLimit > 0);
+        foreignDailyLimit = _foreignDailyLimit;
+        DailyLimit(foreignDailyLimit);
+    }
+
+    function withinLimit(uint256 _amount) public view returns(bool) {
+        uint256 nextLimit = totalSpentPerDay[getCurrentDay()].add(_amount);
+        return foreignDailyLimit >= nextLimit;
+    }
 
-    // /// Get message
-    // function message(bytes32 hash) public view returns (bytes) {
-    //     return signatures[hash].message;
-    // }
-}
+}