Add xkton convertor

helix-contract/address/xtoken-product.json

@@ -31,9 +31,12 @@
         "darwinia-dvm(to ethereum)": "0x092e19c46c9daab7824393f1cd9c22f5bea13560",
         "crab-dvm(to darwinia)": "0x004D0dE211BC148c3Ce696C51Cbc85BD421727E9"
     },
-    "xtokenConvertor": {
+    "xRINGConvertor": {
         "ethereum": "0xc29dCb1F12a1618262eF9FBA673b77140adc02D6"
     },
+    "xKTONConvertor": {
+        "ethereum": "0x3217F36AE34aCA2CE60d218af8F47d29101204a8"
+    },
     "guard": {
         "ethereum": "0x4CA75992d2750BEC270731A72DfDedE6b9E71cC7",
         "darwinia-dvm": "0x4ca75992d2750bec270731a72dfdede6b9e71cc7"
@@ -45,6 +48,7 @@
     "xtoken": {
         "darwinia-dvm(xWCRAB)": "0x656567Eb75b765FC320783cc6EDd86bD854b2305",
         "crab-dvm(xWRING)": "0x273131F7CB50ac002BDd08cA721988731F7e1092",
-        "ethereum(xRING)": "0x81e32d4652Be82AE225DEdd1bD0bf3BCba8FEE07 "
+        "ethereum(xRING)": "0x81e32d4652Be82AE225DEdd1bD0bf3BCba8FEE07 ",
+        "ethereum(xKTON)": "0x35f15275041B53324dF461d5ccC952EE19D4a982" 
     }
 }

helix-contract/contracts/xtoken/v3/templates/XKTONConvertor.sol

@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: Apache-2.0
+
+pragma solidity >=0.8.17;
+
+import "@zeppelin-solidity/contracts/token/ERC20/IERC20.sol";
+import "@zeppelin-solidity/contracts/utils/introspection/ERC165.sol";
+import "./interfaces/IXKTONLockBox.sol";
+import "../interfaces/IXTokenIssuing.sol";
+import "../interfaces/IXTokenCallback.sol";
+
+contract XKTONConvertor is IXTokenCallback, IXTokenRollbackCallback, ERC165 {
+    IXKTONLockBox public lockBox;
+    IXTokenIssuing public xTokenIssuing;
+    address public immutable KTON;
+    address public immutable XKTON;
+
+    mapping(uint256=>address) public senders;
+
+    event IssueKTON(uint256 transferId, address recipient, uint256 amount);
+    event RollbackBurn(uint256 transferId, address originalSender, uint256 amount);
+    event BurnAndXUnlock(uint256 transferId, address sender, address recipient, uint256 amount);
+
+    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165) returns (bool) {
+        return
+            interfaceId == type(IXTokenCallback).interfaceId ||
+            interfaceId == type(IXTokenRollbackCallback).interfaceId ||
+            super.supportsInterface(interfaceId);
+    }
+
+    receive() external payable {}
+
+    modifier onlyXTokenIssuing() {
+        require(address(xTokenIssuing) == msg.sender, "invalid sender");
+        _;
+    }
+
+    modifier onlyXTokenIssuingAuthorized() {
+        require(address(xTokenIssuing) == msg.sender || xTokenIssuing.guard() == msg.sender, "invalid sender");
+        _;
+    }
+
+    constructor(address _xKTON, address _kton, address _xTokenIssuing, address _lockBox) {
+        KTON = _kton;
+        XKTON = _xKTON;
+        lockBox = IXKTONLockBox(_lockBox);
+        xTokenIssuing = IXTokenIssuing(_xTokenIssuing);
+        IERC20(_kton).approve(_lockBox, type(uint256).max);
+        IERC20(_xKTON).approve(_lockBox, type(uint256).max);
+        IERC20(_xKTON).approve(_xTokenIssuing, type(uint256).max);
+    }
+
+    function xTokenCallback(
+        uint256 _transferId,
+        address _xToken,
+        uint256 _amount,
+        bytes calldata extData
+    ) onlyXTokenIssuingAuthorized external {
+        address recipient = address(bytes20(extData));
+        require(_xToken == XKTON, "invalid xtoken");
+        lockBox.depositFor(recipient, _amount);
+        emit IssueKTON(_transferId, recipient, _amount);
+    }
+
+    function xTokenRollbackCallback(
+        uint256 _transferId,
+        address _xToken,
+        uint256 _amount
+    ) onlyXTokenIssuing external {
+        require(_xToken == XKTON, "invalid xtoken");
+        address originalSender = senders[_transferId];
+        lockBox.depositFor(originalSender, _amount);
+        emit RollbackBurn(_transferId, originalSender, _amount);
+    }
+
+    function burnAndXUnlock(
+        address _recipient,
+        address _rollbackAccount,
+        uint256 _amount,
+        uint256 _nonce,
+        bytes calldata _extData,
+        bytes memory _extParams
+    ) payable external {
+        IERC20(KTON).transferFrom(msg.sender, address(this), _amount);
+        lockBox.withdraw(_amount);
+        bytes32 transferId = xTokenIssuing.burnAndXUnlock{value: msg.value}(XKTON, _recipient, _rollbackAccount, _amount, _nonce, _extData, _extParams);
+        uint256 id = uint256(transferId);
+        senders[id] = msg.sender;
+        emit BurnAndXUnlock(id, msg.sender, _recipient, _amount);
+    }
+}
+

helix-contract/contracts/xtoken/v3/templates/interfaces/IXKTONLockBox.sol

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: MIT
+pragma solidity >=0.8.17;
+
+interface IXKTONLockBox {
+    function depositFor(address to, uint256 amount) external;
+    function withdraw(uint256 amount) external;
+}