Add wormhole bridge

.eslintrc.json

@@ -100,7 +100,7 @@
     "no-tabs": "error",
     "no-this-before-super": "error",
     "no-throw-literal": "error",
-    "no-unexpected-multiline": "error",
+    "no-unexpected-multiline": "off",
     "no-unmodified-loop-condition": "error",
     "no-unneeded-ternary": [
       "error",

.github/workflows/slither.yml

@@ -0,0 +1,20 @@
+name: Slither
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  analyze:
+    name: Slither
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Run Slither
+        uses: crytic/[email protected]
+        with:
+          node-version: 12

.github/workflows/tests.yml

@@ -39,6 +39,14 @@ jobs:
       - run: yarn codechecks # compares gas report
         env: # Or as an environment variable
           CC_SECRET: ${{ secrets.CC_SECRET }}
+      - run: yarn coverage
+      - name: Archive code coverage results
+        uses: actions/upload-artifact@v2
+        with:
+          name: code-coverage-artifacts
+          path: |
+            coverage
+            coverage.json
 
   test-e2e:
     name: Tests E2E

.gitignore

@@ -7,6 +7,7 @@ artifacts-ovm
 cache-ovm
 .env
 gasReporterOutput.json
+coverage*
 
 # echidna
 crytic-export/

.solcover.js

@@ -0,0 +1,5 @@
+module.exports = {
+  measureStatementCoverage: false,
+  measureFunctionCoverage: false,
+  skipFiles: ['test'],
+}

README.md

@@ -1,12 +1,17 @@
 [![Lint](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/lint.yml/badge.svg)](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/lint.yml)
-[![Check](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/check.yml/badge.svg)](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/check.yml)
+[![Slither](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/slither.yml/badge.svg)](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/slither.yml)
 [![Tests](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/tests.yml/badge.svg)](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/tests.yml)
 [![Fuzz](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/fuzz.yml/badge.svg)](https://github.com/makerdao/optimism-dai-bridge/actions/workflows/fuzz.yml)
 
 # Optimism Dai Bridge
 
 Optimism Dai and upgradable token bridge
 
+## Security
+
+Smart contracts stored in this repository are part of the bug bounty. To disclose any vulnerability please refer to the
+[bug bounty page](https://immunefi.com/bounty/makerdao/).
+
 ## Contracts
 
 - `dai.sol` - Improved DAI contract.
@@ -137,13 +142,16 @@ Run `yarn test:fix` to run linting in fix mode, auto-formatting and unit tests.
 
 Running `yarn test` makes sure that contracts are compiled. Running `yarn test-e2e` doesn't.
 
+Run `yarn coverage` to run solidity-coverage.
+
 ## Fuzzing
 
 ### Install Echidna
 
 - Precompiled Binaries (recommended)
 
 Before starting, make sure Slither is installed:
+
 ```
 $ pip3 install slither-analyzer
 ```

contracts/common/WormholeGUID.sol

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (C) 2021 Dai Foundation
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+pragma solidity >=0.7.6;
+
+// Standard Maker Wormhole GUID
+struct WormholeGUID {
+  bytes32 sourceDomain;
+  bytes32 targetDomain;
+  bytes32 receiver;
+  bytes32 operator;
+  uint128 amount;
+  uint80 nonce;
+  uint48 timestamp;
+}
+
+function bytes32ToAddress(bytes32 addr) pure returns (address) {
+  return address(uint160(uint256(addr)));
+}
+
+function addressToBytes32(address addr) pure returns (bytes32) {
+  return bytes32(uint256(uint160(addr)));
+}

contracts/common/WormholeInterfaces.sol

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (C) 2021 Dai Foundation
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+pragma solidity >=0.7.6;
+pragma abicoder v2;
+import {WormholeGUID} from "./WormholeGUID.sol";
+
+interface IL1WormholeRouter {
+  function requestMint(
+    WormholeGUID calldata wormholeGUID,
+    uint256 maxFeePercentage,
+    uint256 operatorFee
+  ) external returns (uint256 postFeeAmount, uint256 totalFee);
+
+  function settle(bytes32 targetDomain, uint256 batchedDaiToFlush) external;
+}
+
+interface IL1WormholeGateway {
+  function l1Token() external view returns (address);
+
+  function l1Escrow() external view returns (address);
+
+  function l1WormholeRouter() external view returns (IL1WormholeRouter);
+
+  function l2WormholeGateway() external view returns (address);
+
+  function finalizeFlush(bytes32 targetDomain, uint256 daiToFlush) external;
+
+  function finalizeRegisterWormhole(WormholeGUID calldata wormhole) external;
+}
+
+interface IL2WormholeGateway {
+  event WormholeInitialized(WormholeGUID wormhole);
+  event Flushed(bytes32 indexed targetDomain, uint256 dai);
+
+  function l2Token() external view returns (address);
+
+  function l1WormholeGateway() external view returns (address);
+
+  function domain() external view returns (bytes32);
+
+  function initiateWormhole(
+    bytes32 targetDomain,
+    address receiver,
+    uint128 amount
+  ) external;
+
+  function initiateWormhole(
+    bytes32 targetDomain,
+    address receiver,
+    uint128 amount,
+    address operator
+  ) external;
+
+  function initiateWormhole(
+    bytes32 targetDomain,
+    bytes32 receiver,
+    uint128 amount,
+    bytes32 operator
+  ) external;
+
+  function flush(bytes32 targetDomain) external;
+}

contracts/l1/L1DaiWormholeGateway.sol

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (C) 2021 Dai Foundation
+// @unsupported: ovm
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+pragma solidity >=0.7.6;
+pragma abicoder v2;
+
+import {iOVM_L1ERC20Bridge} from "@eth-optimism/contracts/iOVM/bridge/tokens/iOVM_L1ERC20Bridge.sol";
+import {iOVM_L2ERC20Bridge} from "@eth-optimism/contracts/iOVM/bridge/tokens/iOVM_L2ERC20Bridge.sol";
+import {OVM_CrossDomainEnabled} from "@eth-optimism/contracts/libraries/bridge/OVM_CrossDomainEnabled.sol";
+import {WormholeGUID} from "../common/WormholeGUID.sol";
+import {IL1WormholeGateway, IL1WormholeRouter} from "../common/WormholeInterfaces.sol";
+
+interface TokenLike {
+  function approve(address, uint256) external returns (bool);
+
+  function transferFrom(
+    address _from,
+    address _to,
+    uint256 _value
+  ) external returns (bool success);
+}
+
+contract L1DaiWormholeGateway is OVM_CrossDomainEnabled, IL1WormholeGateway {
+  address public immutable override l1Token;
+  address public immutable override l2WormholeGateway;
+  address public immutable override l1Escrow;
+  IL1WormholeRouter public immutable override l1WormholeRouter;
+
+  constructor(
+    address _l1Token,
+    address _l2WormholeGateway,
+    address _l1Messenger,
+    address _l1Escrow,
+    address _l1WormholeRouter
+  ) OVM_CrossDomainEnabled(_l1Messenger) {
+    l1Token = _l1Token;
+    l2WormholeGateway = _l2WormholeGateway;
+    l1Escrow = _l1Escrow;
+    l1WormholeRouter = IL1WormholeRouter(_l1WormholeRouter);
+    // Approve the router to pull DAI from this contract during settle() (after the DAI has been pulled by this contract from the escrow)
+    TokenLike(_l1Token).approve(_l1WormholeRouter, type(uint256).max);
+  }
+
+  function finalizeFlush(bytes32 targetDomain, uint256 daiToFlush)
+    external
+    override
+    onlyFromCrossDomainAccount(l2WormholeGateway)
+  {
+    // Pull DAI from the escrow to this contract
+    TokenLike(l1Token).transferFrom(l1Escrow, address(this), daiToFlush);
+    // The router will pull the DAI from this contract
+    l1WormholeRouter.settle(targetDomain, daiToFlush);
+  }
+
+  function finalizeRegisterWormhole(WormholeGUID calldata wormhole)
+    external
+    override
+    onlyFromCrossDomainAccount(l2WormholeGateway)
+  {
+    l1WormholeRouter.requestMint(wormhole, 0, 0);
+  }
+}