[PT1-347] Feature/permit2 without witness

contracts/extensions/Permit2Proxy.sol

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity 0.8.30;
+
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+import "../interfaces/IPermit2TransferFrom.sol";
+import "./ImmutableOwner.sol";
+
+/* solhint-disable func-name-mixedcase */
+
+contract Permit2Proxy is ImmutableOwner {
+    error Permit2ProxyBadSelector();
+
+    IPermit2TransferFrom private constant _PERMIT2 = IPermit2TransferFrom(0x000000000022D473030F116dDEE9F6B43aC78BA3);
+
+    constructor(address _immutableOwner) ImmutableOwner(_immutableOwner) {
+        if (Permit2Proxy.func_nZHTch.selector != IERC20.transferFrom.selector) revert Permit2ProxyBadSelector();
+    }
+
+    /// @notice Proxy transfer method for `Permit2.permitTransferFrom`. Selector must match `IERC20.transferFrom`
+    // keccak256("func_nZHTch(address,address,uint256,((address,uint256),uint256,uint256),bytes)") == 0x23b872dd (IERC20.transferFrom)
+    function func_nZHTch(
+        address from,
+        address to,
+        uint256 amount,
+        IPermit2TransferFrom.PermitTransferFrom calldata permit,
+        bytes calldata sig
+    ) external onlyImmutableOwner {
+        _PERMIT2.permitTransferFrom(
+            permit,
+            IPermit2TransferFrom.SignatureTransferDetails({
+                to: to,
+                requestedAmount: amount
+            }),
+            from,
+            sig
+        );
+    }
+}
+
+/* solhint-enable func-name-mixedcase */

contracts/interfaces/IPermit2TransferFrom.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+interface IPermit2TransferFrom {
+    struct TokenPermissions {
+        // ERC20 token address
+        address token;
+        // the maximum amount that can be spent
+        uint256 amount;
+    }
+
+    struct PermitTransferFrom {
+        TokenPermissions permitted;
+        // a unique value for every token owner's signature to prevent signature replays
+        uint256 nonce;
+        // deadline on the permit signature
+        uint256 deadline;
+    }
+
+    struct SignatureTransferDetails {
+        // recipient address
+        address to;
+        // spender requested amount
+        uint256 requestedAmount;
+    }
+
+    function permitTransferFrom(
+        PermitTransferFrom calldata permit,
+        SignatureTransferDetails calldata transferDetails,
+        address owner,
+        bytes calldata signature
+    ) external;
+}

dev.md

@@ -0,0 +1,21 @@
+# Development Guide
+
+## Selector Bruteforce Tool
+
+When developing proxy contracts that need specific function selectors (e.g., matching `IERC20.transferFrom` selector `0x23b872dd`), use the selector bruteforce tool from:
+
+**https://github.com/1inch/smart-contract-helper-utils/src**
+
+### Usage Example
+
+To find a function name with custom suffix that produces the `transferFrom` selector:
+
+```bash
+python selector_bruteforce.py \
+  --target 0x23b872dd \
+  --params "address,address,uint256,((address,uint256),uint256,uint256),bytes" \
+  --prefix "func_" \
+  --fast
+```
+
+This is used for contracts like `Permit2Proxy` and `Permit2WitnessProxy` where the proxy function must have the same selector as `transferFrom` to work with the limit order protocol's extension mechanism.

docs/extensions/Permit2Proxy.md

@@ -0,0 +1,37 @@
+
+## Permit2Proxy
+
+A proxy contract that enables using Uniswap's Permit2 `permitTransferFrom` within the limit order protocol without the witness functionality.
+
+### Functions list
+- [constructor(_immutableOwner) public](#constructor)
+- [func_nZHTch(from, to, amount, permit, sig) external](#func_nzhtch)
+
+### Errors list
+- [Permit2ProxyBadSelector()](#permit2proxybadselector)
+
+### Functions
+### constructor
+
+```solidity
+constructor(address _immutableOwner) public
+```
+
+### func_nZHTch
+
+```solidity
+function func_nZHTch(address from, address to, uint256 amount, struct IPermit2TransferFrom.PermitTransferFrom permit, bytes sig) external
+```
+Proxy transfer method for `Permit2.permitTransferFrom`. Selector must match `IERC20.transferFrom`
+
+The function name `func_nZHTch` is chosen so that its selector equals `0x23b872dd` (same as `IERC20.transferFrom`), allowing it to be used as a maker asset in limit orders.
+
+### Errors
+### Permit2ProxyBadSelector
+
+```solidity
+error Permit2ProxyBadSelector()
+```
+
+Thrown in the constructor if the function selector doesn't match `IERC20.transferFrom.selector`.
+

test/Permit2Proxy.js

@@ -0,0 +1,85 @@
+const { constants, permit2Contract } = require('@1inch/solidity-utils');
+const { SignatureTransfer, PERMIT2_ADDRESS } = require('@uniswap/permit2-sdk');
+const { ether } = require('./helpers/utils');
+const { signOrder, buildOrder, buildTakerTraits, buildMakerTraitsRFQ } = require('./helpers/orderUtils');
+const { deploySwapTokens } = require('./helpers/fixtures');
+const { nextPermit2Nonce } = require('./helpers/nonce');
+const hre = require('hardhat');
+const { ethers } = hre;
+
+describe('Permit2Proxy', function () {
+    let addr, addr1;
+
+    before(async function () {
+        [addr, addr1] = await ethers.getSigners();
+    });
+
+    it('permit2 example (without witness)', async function () {
+        const { dai, weth, swap, chainId } = await deploySwapTokens();
+
+        await dai.mint(addr, ether('2000'));
+        await weth.connect(addr1).deposit({ value: ether('1') });
+        await dai.approve(swap, ether('2000'));
+        await weth.connect(addr1).approve(PERMIT2_ADDRESS, ether('1'));
+
+        const Permit2Proxy = await ethers.getContractFactory('Permit2Proxy');
+        const permit2Proxy = await Permit2Proxy.deploy(await swap.getAddress());
+        await permit2Proxy.waitForDeployment();
+
+        await permit2Contract();
+
+        const permit = {
+            permitted: {
+                token: await weth.getAddress(),
+                amount: ether('1'),
+            },
+            spender: await permit2Proxy.getAddress(),
+            nonce: nextPermit2Nonce(),
+            deadline: 0xffffffff,
+        };
+
+        const data = SignatureTransfer.getPermitData(
+            permit,
+            PERMIT2_ADDRESS,
+            chainId,
+        );
+
+        const sig = ethers.Signature.from(await addr1.signTypedData(data.domain, data.types, data.values));
+
+        const makerAssetSuffix = '0x' + permit2Proxy.interface.encodeFunctionData('func_nZHTch', [
+            constants.ZERO_ADDRESS, constants.ZERO_ADDRESS, 0,
+            {
+                permitted: {
+                    token: permit.permitted.token,
+                    amount: permit.permitted.amount,
+                },
+                nonce: permit.nonce,
+                deadline: permit.deadline,
+            },
+            sig.compactSerialized,
+        ]).substring(202);
+
+        const order = buildOrder(
+            {
+                maker: addr1.address,
+                makerAsset: await permit2Proxy.getAddress(),
+                takerAsset: await dai.getAddress(),
+                makingAmount: ether('1'),
+                takingAmount: ether('2000'),
+                makerTraits: buildMakerTraitsRFQ(),
+            },
+            {
+                makerAssetSuffix,
+            },
+        );
+
+        const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
+        const takerTraits = buildTakerTraits({
+            makingAmount: true,
+            extension: order.extension,
+            threshold: order.takingAmount,
+        });
+
+        await swap.fillOrderArgs(order, r, vs, order.makingAmount, takerTraits.traits, takerTraits.args);
+    });
+});

test/WitnessProxyExample.js

@@ -3,6 +3,7 @@ const { SignatureTransfer, PERMIT2_ADDRESS } = require('@uniswap/permit2-sdk');
 const { ether } = require('./helpers/utils');
 const { signOrder, buildOrder, buildTakerTraits, buildMakerTraitsRFQ } = require('./helpers/orderUtils');
 const { deploySwapTokens } = require('./helpers/fixtures');
+const { nextPermit2Nonce } = require('./helpers/nonce');
 const hre = require('hardhat');
 const { ethers } = hre;
 
@@ -20,7 +21,6 @@ describe('WitnessProxyExample', function () {
 
         await dai.mint(addr, ether('2000'));
         await weth.connect(addr1).deposit({ value: ether('1') });
-
         await dai.approve(swap, ether('2000'));
         await weth.connect(addr1).approve(PERMIT2_ADDRESS, ether('1'));
 
@@ -36,7 +36,7 @@ describe('WitnessProxyExample', function () {
                 amount: ether('1'),
             },
             spender: await permit2WitnessProxy.getAddress(),
-            nonce: 0,
+            nonce: nextPermit2Nonce(),
             deadline: 0xffffffff,
         };
 
@@ -49,7 +49,7 @@ describe('WitnessProxyExample', function () {
         const data = SignatureTransfer.getPermitData(
             permit,
             PERMIT2_ADDRESS,
-            31337,
+            chainId,
             witness,
         );
 

test/helpers/nonce.js

@@ -0,0 +1,14 @@
+let currentNonce = 0n;
+
+/**
+ * Returns a unique nonce for Permit2 SignatureTransfer.
+ * Uses global state to ensure each call returns a different nonce.
+ * @returns {bigint} A unique nonce
+ */
+function nextPermit2Nonce () {
+    return currentNonce++;
+}
+
+module.exports = {
+    nextPermit2Nonce,
+};