Sovereign bridge implementation

contracts/PolygonZkEVMGlobalExitRootL2.sol

@@ -27,6 +27,12 @@ contract PolygonZkEVMGlobalExitRootL2 is IBasePolygonZkEVMGlobalExitRoot {
     // PolygonZkEVM Bridge address
     address public immutable bridgeAddress;
 
+    /**
+     * @dev This empty reserved space is put in place to allow future versions to add new
+     * variables without shifting down storage in the inheritance chain.
+     */
+    uint256[50] private _gap;
+
     /**
      * @param _bridgeAddress PolygonZkEVMBridge contract address
      */

contracts/interfaces/IBasePolygonZkEVMGlobalExitRoot.sol

@@ -8,6 +8,11 @@ interface IBasePolygonZkEVMGlobalExitRoot {
      */
     error OnlyAllowedContracts();
 
+    /**
+     * @dev Thrown when the caller is not the coinbase
+     */
+    error OnlyCoinbase();
+
     function updateExitRoot(bytes32 newRollupExitRoot) external;
 
     function globalExitRootMap(

contracts/v2/PolygonZkEVMBridgeV2.sol

@@ -91,6 +91,12 @@ contract PolygonZkEVMBridgeV2 is
     // WETH address
     TokenWrapped public WETHToken;
 
+    /**
+     * @dev This empty reserved space is put in place to allow future versions to add new
+     * variables without shifting down storage in the inheritance chain.
+     */
+    uint256[50] private _gap;
+
     /**
      * @dev Emitted when bridge assets or messages to another network
      */
@@ -150,7 +156,7 @@ contract PolygonZkEVMBridgeV2 is
         IBasePolygonZkEVMGlobalExitRoot _globalExitRootManager,
         address _polygonRollupManager,
         bytes memory _gasTokenMetadata
-    ) external virtual initializer {
+    ) public virtual initializer {
         networkID = _networkID;
         globalExitRootManager = _globalExitRootManager;
         polygonRollupManager = _polygonRollupManager;
@@ -238,7 +244,7 @@ contract PolygonZkEVMBridgeV2 is
             // In case ether is the native token, WETHToken will be 0, and the address 0 is already checked
             if (token == address(WETHToken)) {
                 // Burn tokens
-                TokenWrapped(token).burn(msg.sender, amount);
+                _bridgeWrappedAsset(TokenWrapped(token), amount);
 
                 // Both origin network and originTokenAddress will be 0
                 // Metadata will be empty
@@ -250,8 +256,7 @@ contract PolygonZkEVMBridgeV2 is
                 if (tokenInfo.originTokenAddress != address(0)) {
                     // The token is a wrapped token from another network
 
-                    // Burn tokens
-                    TokenWrapped(token).burn(msg.sender, amount);
+                    _bridgeWrappedAsset(TokenWrapped(token), amount);
 
                     originTokenAddress = tokenInfo.originTokenAddress;
                     originNetwork = tokenInfo.originNetwork;
@@ -364,7 +369,7 @@ contract PolygonZkEVMBridgeV2 is
         }
 
         // Burn wETH tokens
-        WETHToken.burn(msg.sender, amountWETH);
+        _bridgeWrappedAsset(WETHToken, amountWETH);
 
         _bridgeMessage(
             destinationNetwork,
@@ -492,7 +497,7 @@ contract PolygonZkEVMBridgeV2 is
                 }
             } else {
                 // Claim wETH
-                WETHToken.mint(destinationAddress, amount);
+                _claimWrappedAsset(WETHToken, destinationAddress, amount);
             }
         } else {
             // Check if it's gas token
@@ -536,7 +541,11 @@ contract PolygonZkEVMBridgeV2 is
                         );
 
                         // Mint tokens for the destination address
-                        newWrappedToken.mint(destinationAddress, amount);
+                        _claimWrappedAsset(
+                            newWrappedToken,
+                            destinationAddress,
+                            amount
+                        );
 
                         // Create mappings
                         tokenInfoToWrappedToken[tokenInfoHash] = address(
@@ -555,7 +564,8 @@ contract PolygonZkEVMBridgeV2 is
                         );
                     } else {
                         // Use the existing wrapped erc20
-                        TokenWrapped(wrappedToken).mint(
+                        _claimWrappedAsset(
+                            TokenWrapped(wrappedToken),
                             destinationAddress,
                             amount
                         );
@@ -608,7 +618,7 @@ contract PolygonZkEVMBridgeV2 is
         address destinationAddress,
         uint256 amount,
         bytes calldata metadata
-    ) external ifNotEmergencyState {
+    ) external virtual ifNotEmergencyState {
         // Destination network must be this networkID
         if (destinationNetwork != networkID) {
             revert DestinationNetworkInvalid();
@@ -646,7 +656,7 @@ contract PolygonZkEVMBridgeV2 is
             );
         } else {
             // Mint wETH tokens
-            WETHToken.mint(destinationAddress, amount);
+            _claimWrappedAsset(WETHToken, destinationAddress, amount);
 
             // Execute message
             /* solhint-disable avoid-low-level-calls */
@@ -895,6 +905,36 @@ contract PolygonZkEVMBridgeV2 is
         globalExitRootManager.updateExitRoot(getRoot());
     }
 
+    /**
+     * @notice Burn tokens from wrapped token to execute the bridge
+     * note This  function has been extracted to be able to override it by other contracts like Bridge2SovereignChain
+     * @param tokenWrapped Wrapped token to burnt
+     * @param amount Amount of tokens
+     */
+    function _bridgeWrappedAsset(
+        TokenWrapped tokenWrapped,
+        uint256 amount
+    ) internal virtual {
+        // Burn tokens
+        tokenWrapped.burn(msg.sender, amount);
+    }
+
+    /**
+     * @notice Mints tokens from wrapped token to proceed with the claim
+     * note This  function has been extracted to be able to override it by other contracts like Bridge2SovereignChain
+     * @param tokenWrapped Wrapped token to mint
+     * @param destinationAddress Minted token receiver
+     * @param amount Amount of tokens
+     */
+    function _claimWrappedAsset(
+        TokenWrapped tokenWrapped,
+        address destinationAddress,
+        uint256 amount
+    ) internal virtual {
+        // Burn tokens
+        tokenWrapped.mint(destinationAddress, amount);
+    }
+
     /**
      * @notice Function decode an index into a wordPos and bitPos
      * @param index Index

contracts/v2/interfaces/IBridgeL2SovereignChains.sol

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: AGPL-3.0
+
+pragma solidity ^0.8.20;
+import "../../interfaces/IBasePolygonZkEVMGlobalExitRoot.sol";
+import "./IPolygonZkEVMBridgeV2.sol";
+
+interface IBridgeL2SovereignChains is IPolygonZkEVMBridgeV2 {
+    /**
+     * @dev Thrown when try to set a zero address to a non valid zero address field
+     */
+    error InvalidZeroAddress();
+
+    /**
+     * @dev Thrown when the origin network is invalid
+     */
+    error OriginNetworkInvalid();
+
+    /**
+     * @dev Thrown when sender is not the bridge manager
+     * @notice Bridge manager can set custom mapping for any token
+     */
+    error OnlyBridgeManager();
+
+    /**
+     * @dev Thrown when bridge manager address is invalid
+     */
+    error NotValidBridgeManager();
+
+    /**
+     * @dev Thrown when trying to remove a token mapping that has not been mapped before
+     */
+    error TokenNotMapped();
+
+    function initialize(
+        uint32 _networkID,
+        address _gasTokenAddress,
+        uint32 _gasTokenNetwork,
+        IBasePolygonZkEVMGlobalExitRoot _globalExitRootManager,
+        address _polygonRollupManager,
+        bytes memory _gasTokenMetadata,
+        address _bridgeManager
+    ) external;
+}