Merge pull request #42 from bob-collective/feat/proof-checking

feat: proof checking and relay init

script/Bridge.s.sol

@@ -2,11 +2,31 @@
 pragma solidity ^0.8.13;
 
 import {Script, console2} from "forge-std/Script.sol";
+import "../src/relay/LightRelay.sol";
 
 contract BridgeScript is Script {
     function setUp() public {}
 
     function run() public {
-        vm.broadcast();
+        bytes memory data =
+            hex"04000000473ed7b7ef2fce828c318fd5e5868344a5356c9e93b6040400000000000000004409cae5b7b2f8f18ea55f558c9bfa7c5f4778a1a53172a48fc57e172d0ed3d264c5eb56c3a40618af9bc1c7";
+        uint256 height = 403200;
+
+        uint256 deployerPrivateKey = vm.envUint("PRIVATE_KEY");
+
+        bytes memory genesisHeader = vm.envBytes("GENESIS_HEADER");
+        uint256 genesisHeight = vm.envUint("GENESIS_HEIGHT");
+        bytes memory retargetHeaders = vm.envBytes("RETARGET_HEADERS");
+
+        vm.startBroadcast(deployerPrivateKey);
+        LightRelay relay = new LightRelay();
+
+        // Initialize relay at the given block
+        relay.genesis(genesisHeader, genesisHeight, 1);
+
+        // submit retarget
+        relay.retarget(retargetHeaders);
+
+        vm.stopBroadcast();
     }
 }

sdk/package.json

@@ -5,6 +5,7 @@
   "types": "dist/index.d.ts",
   "scripts": {
     "test": "ts-mocha test/*.ts",
+    "deploy-relay": "ts-node scripts/init-bridge.ts",
     "build": "tsc -p tsconfig.json"
   },
   "files": [
@@ -25,7 +26,8 @@
     "tiny-secp256k1": "^2.2.3",
     "ts-mocha": "^10.0.0",
     "ts-node-dev": "^2.0.0",
-    "typescript": "^5.2.2"
+    "typescript": "^5.2.2",
+    "yargs": "^17.5.1"
   },
   "dependencies": {
     "bitcoinjs-lib": "^6.1.5"

sdk/scripts/init-bridge.ts

@@ -0,0 +1,54 @@
+/* eslint @typescript-eslint/no-var-requires: "off" */
+
+import { DefaultElectrsClient } from "../src/electrs";
+const yargs = require("yargs/yargs");
+const { hideBin } = require("yargs/helpers");
+const { exec } = require('child_process');
+
+const args = yargs(hideBin(process.argv))
+    .option("init-height", {
+        description: "Height of the bitcoin chain to initialize the relay at",
+        type: "number",
+        demandOption: true,
+    })
+    .option("private-key", {
+        description: "Private key to submit with",
+        type: "string",
+        demandOption: true,
+    }).argv;
+main().catch((err) => {
+    console.log("Error thrown by script:");
+    console.log(err);
+});
+
+
+async function main(): Promise<void> {
+    const electrs = new DefaultElectrsClient("testnet");
+    // args["parachain-endpoint"]
+
+    const initHeight = args["init-height"];
+    const privateKey = args["private-key"];
+    if ((initHeight % 2016) != 0) {
+        throw new Error("Invalid genesis height: must be multiple of 2016");
+    }
+
+    const genesis = await electrs.getBlockHeaderAt(initHeight);
+
+    const beforeRetarget = await electrs.getBlockHeaderAt(initHeight + 2015);
+    const afterRetarget = await electrs.getBlockHeaderAt(initHeight + 2016);
+
+    console.log(`Genesis: ${genesis}`);
+    console.log(`beforeRetarget: ${beforeRetarget}`);
+    console.log(`afterRetarget: ${afterRetarget}`);
+
+
+    exec(`GENESIS_HEIGHT=${initHeight} GENESIS_HEADER=${genesis} RETARGET_HEADERS=${beforeRetarget}${afterRetarget} PRIVATE_KEY=${privateKey} forge script script/Bridge.s.sol:BridgeScript --rpc-url 'https://l2-fluffy-bob-7mjgi9pmtg.t.conduit.xyz' --chain 901 --verify --verifier blockscout --verifier-url 'https://explorerl2-fluffy-bob-7mjgi9pmtg.t.conduit.xyz/api?' --broadcast`, 
+        (err: any, stdout: any, stderr: any) => {
+        if (err) {
+            throw new Error(`Failed to run command: ${err}`);
+        }
+
+        // the *entire* stdout and stderr (buffered)
+        console.log(`stdout: ${stdout}`);
+      });
+}

sdk/src/electrs.ts

@@ -192,6 +192,14 @@ export class DefaultElectrsClient implements ElectrsClient {
         return this.getText(`${this.basePath}/block/${hash}/header`);
     }
 
+    /**
+     * @ignore
+     */
+    async getBlockHeaderAt(height: number): Promise<string> {
+        const blockHash = await this.getBlockHash(height);
+        return await this.getBlockHeader(blockHash);
+    }
+
     /**
      * @ignore
      */

src/bridge/BitcoinTx.sol

@@ -184,6 +184,12 @@ library BitcoinTx {
         bytes memory bitcoinHeaders
     ) internal view {
         IRelay relay = self.relay;
+
+        // for testing
+        if (!relay.difficultyCheckEnabled()) {
+            return;
+        }
+
         uint256 currentEpochDifficulty = relay.getCurrentEpochDifficulty();
         uint256 previousEpochDifficulty = relay.getPrevEpochDifficulty();
 

src/bridge/IRelay.sol

@@ -14,4 +14,7 @@ interface IRelay {
 
     /// @notice Returns the difficulty of the previous epoch.
     function getPrevEpochDifficulty() external view returns (uint256);
+
+    /// @notice Returns true iff difficulty check should be performed.
+    function difficultyCheckEnabled() external view returns (bool);
 }

src/relay/DummyRelay.sol

@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Forked from https://github.com/keep-network/tbtc-v2
+
+pragma solidity 0.8.17;
+
+import "@openzeppelin/contracts/access/Ownable.sol";
+
+import {BytesLib} from "@bob-collective/bitcoin-spv/BytesLib.sol";
+import {BTCUtils} from "@bob-collective/bitcoin-spv/BTCUtils.sol";
+import {ValidateSPV} from "@bob-collective/bitcoin-spv/ValidateSPV.sol";
+
+import "../bridge/IRelay.sol";
+
+/// @dev DEV-only!
+contract DummyRelay is IRelay {
+    function getCurrentEpochDifficulty() external view returns (uint256) {
+        return 0;
+    }
+
+    function getPrevEpochDifficulty() external view returns (uint256) {
+        return 0;
+    }
+
+    function difficultyCheckEnabled() external view returns (bool) {
+        return false;
+    }
+}

src/relay/LightRelay.sol

@@ -550,6 +550,11 @@ contract LightRelay is Ownable, ILightRelay {
         return (currentEpochDifficulty, prevEpochDifficulty);
     }
 
+    function difficultyCheckEnabled() external view returns (bool) {
+        return true;
+    }
+
+
     /// @notice Get the difficulty of the specified epoch.
     /// @param epochNumber The number of the epoch (the height of the first
     /// block of the epoch, divided by 2016). Must fall within the relay range.

src/swap/Bridge.sol

@@ -20,9 +20,11 @@ contract Bridge {
         address accepterAddress;
         BitcoinAddress bitcoinAddress;
     }
+
     struct BitcoinAddress {
         uint256 bitcoinAddress; // todo: use the right type
     }
+
     struct TransactionProof {
         // todo: fields here
         uint256 dummy;
@@ -43,11 +45,7 @@ contract Bridge {
     }
 
     /// request zBTC to be redeemed for given amount of BTC.
-    function requestSwap(
-        uint256 amountZbtc,
-        uint256 amountBtc,
-        BitcoinAddress calldata bitcoinAddress
-    ) public {
+    function requestSwap(uint256 amountZbtc, uint256 amountBtc, BitcoinAddress calldata bitcoinAddress) public {
         // lock Zbtc by transfering it to the contract address
         wrapped.sudoTransferFrom(msg.sender, address(this), amountZbtc);
         require(amountZbtc != 0);
@@ -79,14 +77,11 @@ contract Bridge {
         require(order.requesterAddress == msg.sender);
         // ensure the request was not accepted yet
         require(order.accepterAddress == address(0));
-        
+
         delete orders[id];
     }
 
-    function executeSwap(
-        uint256 id,
-        TransactionProof calldata transactionProof
-    ) public {
+    function executeSwap(uint256 id, TransactionProof calldata transactionProof) public {
         // todo: check proof
 
         // move the zbtc thta was locked to whoever accepted the order
@@ -96,10 +91,7 @@ contract Bridge {
         require(!order.open);
         require(order.amountZbtc != 0);
 
-        wrapped.transfer(
-            order.accepterAddress,
-            order.amountZbtc
-        );
+        wrapped.transfer(order.accepterAddress, order.amountZbtc);
 
         // clean up storage
         delete orders[id];
@@ -119,18 +111,16 @@ contract Bridge {
         uint256 totalZbtc = wrapped.totalSupply();
         uint256 requiredCol = btcToCol(totalZbtc * collateralThreshold);
         uint256 colFree = totalCollateral - requiredCol;
-        uint256 withdrawal = colFree < suppliedCollateral[msg.sender]
-            ? colFree
-            : suppliedCollateral[msg.sender];
+        uint256 withdrawal = colFree < suppliedCollateral[msg.sender] ? colFree : suppliedCollateral[msg.sender];
         suppliedCollateral[msg.sender] -= withdrawal;
         totalCollateral -= withdrawal;
     }
 
-    function colToBtc(uint256 collateral) internal pure returns (uint) {
+    function colToBtc(uint256 collateral) internal pure returns (uint256) {
         return collateral / 5; // todo
     }
 
-    function btcToCol(uint256 collateral) internal pure returns (uint) {
+    function btcToCol(uint256 collateral) internal pure returns (uint256) {
         return collateral * 5; // todo
     }
 }

src/swap/Btc_Marketplace.sol

@@ -3,10 +3,15 @@ pragma solidity ^0.8.13;
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import {BitcoinTx} from "../bridge/BitcoinTx.sol";
+// import {LightRelay} from "../relay/LightRelay.sol";
+import {IRelay} from "../bridge/IRelay.sol";
+import {BridgeState} from "../bridge/BridgeState.sol";
 
 using SafeERC20 for IERC20;
 
 contract BtcMarketPlace {
+    using BitcoinTx for BridgeState.Storage;
+
     mapping(uint256 => BtcBuyOrder) public btcBuyOrders;
     mapping(uint256 => AcceptedBtcBuyOrder) public acceptedBtcBuyOrders;
     mapping(uint256 => BtcSellOrder) public btcSellOrders;
@@ -15,6 +20,13 @@ contract BtcMarketPlace {
     uint256 nextOrderId;
     uint256 public constant REQUEST_EXPIRATION_SECONDS = 6 hours;
 
+    BridgeState.Storage internal relay;
+
+    constructor(IRelay _relay) {
+        relay.relay = _relay;
+        relay.txProofDifficultyFactor = 1; // will make this an arg later on
+    }
+
     // todo: should we merge buy&sell structs? They're structurally identical except for the
     // bitcoinaddress location.
 
@@ -172,7 +184,7 @@ contract BtcMarketPlace {
 
         require(accept.requester == msg.sender);
 
-        // todo: check proof
+        relay.validateProof(transaction, proof);
 
         IERC20(accept.ercToken).safeTransfer(
             accept.requester,
@@ -293,7 +305,7 @@ contract BtcMarketPlace {
 
         require(accept.accepter == msg.sender);
 
-        // todo: check proof
+        relay.validateProof(transaction, proof);
 
         IERC20(accept.ercToken).safeTransfer(accept.accepter, accept.ercAmount);