ERC721Permit

.forge-snapshots/PositionManager_burn_empty.snap

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.forge-snapshots/PositionManager_burn_empty_native.snap

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.forge-snapshots/PositionManager_burn_nonEmpty.snap

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.forge-snapshots/PositionManager_burn_nonEmpty_native.snap

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.forge-snapshots/PositionManager_collect.snap

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.forge-snapshots/PositionManager_collect_native.snap

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.forge-snapshots/PositionManager_collect_sameRange.snap

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.forge-snapshots/PositionManager_decreaseLiquidity.snap

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.forge-snapshots/PositionManager_decreaseLiquidity_native.snap

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.forge-snapshots/PositionManager_decrease_burnEmpty.snap

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.forge-snapshots/PositionManager_decrease_burnEmpty_native.snap

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.forge-snapshots/PositionManager_decrease_sameRange_allLiquidity.snap

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.forge-snapshots/PositionManager_increaseLiquidity_erc20.snap

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.forge-snapshots/PositionManager_increaseLiquidity_native.snap

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.forge-snapshots/PositionManager_increase_autocompoundExactUnclaimedFees.snap

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.forge-snapshots/PositionManager_increase_autocompoundExcessFeesCredit.snap

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.forge-snapshots/PositionManager_increase_autocompound_clearExcess.snap

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.forge-snapshots/PositionManager_mint.snap

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.forge-snapshots/PositionManager_mint_native.snap

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.forge-snapshots/PositionManager_mint_nativeWithSweep.snap

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.forge-snapshots/PositionManager_mint_onSameTickLower.snap

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.forge-snapshots/PositionManager_mint_onSameTickUpper.snap

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.forge-snapshots/PositionManager_mint_sameRange.snap

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.forge-snapshots/PositionManager_mint_settleWithBalance_sweep.snap

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.forge-snapshots/PositionManager_mint_warmedPool_differentRange.snap

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.forge-snapshots/PositionManager_multicall_initialize_mint.snap

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.forge-snapshots/PositionManager_permit.snap

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.forge-snapshots/PositionManager_permit_secondPosition.snap

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.forge-snapshots/PositionManager_permit_twice.snap

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src/PositionManager.sol

@@ -66,6 +66,11 @@ contract PositionManager is
         _;
     }
 
+    // TODO: to be implemented after audits
+    function tokenURI(uint256) public pure override returns (string memory) {
+        return "https://example.com";
+    }
+
     /// @param unlockData is an encoding of actions, params, and currencies
     /// @param deadline is the timestamp at which the unlockData will no longer be valid
     function modifyLiquidities(bytes calldata unlockData, uint256 deadline)

src/base/ERC721Permit.sol

@@ -1,20 +1,70 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 pragma solidity ^0.8.24;
 
+import {IERC721} from "forge-std/interfaces/IERC721.sol";
 import {ERC721} from "solmate/src/tokens/ERC721.sol";
+import {EIP712} from "@openzeppelin/contracts/utils/cryptography/EIP712.sol";
+import {ERC721PermitHashLibrary} from "../libraries/ERC721PermitHash.sol";
+import {SignatureVerification} from "permit2/src/libraries/SignatureVerification.sol";
 
-/// @notice An ERC721 contract that supports permit.
-/// TODO: Support permit.
-contract ERC721Permit is ERC721 {
-    constructor(string memory name_, string memory symbol_, string memory version_) ERC721(name_, symbol_) {}
+import {IERC721Permit} from "../interfaces/IERC721Permit.sol";
+import {UnorderedNonce} from "./UnorderedNonce.sol";
+
+/// @title ERC721 with permit
+/// @notice Nonfungible tokens that support an approve via signature, i.e. permit
+abstract contract ERC721Permit is ERC721, IERC721Permit, EIP712, UnorderedNonce {
+    using SignatureVerification for bytes;
+
+    /// @notice Computes the nameHash and versionHash
+    constructor(string memory name_, string memory symbol_, string memory version_)
+        ERC721(name_, symbol_)
+        EIP712(name_, version_)
+    {}
+
+    /// @inheritdoc IERC721Permit
+    function DOMAIN_SEPARATOR() external view returns (bytes32) {
+        return _domainSeparatorV4();
+    }
+
+    /// @inheritdoc IERC721Permit
+    function permit(address spender, uint256 tokenId, uint256 deadline, uint256 nonce, bytes calldata signature)
+        external
+        payable
+    {
+        if (block.timestamp > deadline) revert DeadlineExpired();
+
+        address owner = ownerOf(tokenId);
+        if (spender == owner) revert NoSelfPermit();
+
+        bytes32 hash = ERC721PermitHashLibrary.hash(spender, tokenId, nonce, deadline);
+        signature.verify(_hashTypedDataV4(hash), owner);
+
+        _useUnorderedNonce(owner, nonce);
+        _approve(owner, spender, tokenId);
+    }
+
+    /// @notice Change or reaffirm the approved address for an NFT
+    /// @dev override Solmate's ERC721 approve so approve() and permit() share the _approve method
+    /// The zero address indicates there is no approved address
+    /// Throws error unless `msg.sender` is the current NFT owner,
+    /// or an authorized operator of the current owner.
+    /// @param spender The new approved NFT controller
+    /// @param id The tokenId of the NFT to approve
+    function approve(address spender, uint256 id) public override {
+        address owner = _ownerOf[id];
+
+        if (msg.sender != owner && !isApprovedForAll[owner][msg.sender]) revert Unauthorized();
+
+        _approve(owner, spender, id);
+    }
+
+    function _approve(address owner, address spender, uint256 id) internal {
+        getApproved[id] = spender;
+        emit Approval(owner, spender, id);
+    }
 
     function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
         return spender == ownerOf(tokenId) || getApproved[tokenId] == spender
             || isApprovedForAll[ownerOf(tokenId)][spender];
     }
-
-    // TODO: Use PositionDescriptor.
-    function tokenURI(uint256 id) public pure override returns (string memory) {
-        return string(abi.encode(id));
-    }
 }

src/base/UnorderedNonce.sol

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.24;
+
+/// @title Unordered Nonce
+/// @notice Contract state and methods for using unordered nonces in signatures
+contract UnorderedNonce {
+    error NonceAlreadyUsed();
+
+    mapping(address owner => mapping(uint256 word => uint256 bitmap)) public nonces;
+
+    /// @notice Consume a nonce, reverting if its already been used
+    /// @param owner address, the owner/signer of the nonce
+    /// @param nonce uint256, the nonce to consume
+    function _useUnorderedNonce(address owner, uint256 nonce) internal {
+        // consume the bit by flipping it in storage
+        // reverts if the bit was already spent
+        _flipBit(nonces[owner], nonce);
+    }
+
+    function _flipBit(mapping(uint256 => uint256) storage bitmap, uint256 nonce) private {
+        // equivalent to:
+        //   uint256 wordPos = uint248(nonce >> 8);
+        //   uint256 bitPos = uint8(nonce);
+        //   uint256 bit = 1 << bitPos;
+        //   uint256 flipped = nonces[owner][wordPos] ^= bit;
+        //   if (flipped & bit == 0) revert NonceAlreadyUsed();
+
+        assembly ("memory-safe") {
+            // wordPos = uint248(nonce >> 8)
+            let wordPos := shr(8, nonce)
+
+            // bit = 1 << uint8(nonce)
+            let bit := shl(and(nonce, 0xFF), 1)
+
+            // slot of bitmap[wordPos] is keccak256(abi.encode(wordPos, bitmap.slot))
+            mstore(0, wordPos)
+            mstore(0x20, bitmap.slot)
+            let slot := keccak256(0, 0x40)
+
+            // uint256 previousBits = bitmap[wordPos]
+            let previousBits := sload(slot)
+
+            // revert if it's already been used
+            if eq(and(previousBits, bit), bit) {
+                mstore(0, 0x1fb09b80) // 4 bytes of NonceAlreadyUsed.selector
+                revert(0x1c, 0x04)
+            }
+
+            // bitmap[wordPos] = (previousBits | bit)
+            sstore(slot, or(previousBits, bit))
+        }
+    }
+}

src/interfaces/IERC721Permit.sol

@@ -4,11 +4,9 @@ pragma solidity >=0.7.5;
 /// @title ERC721 with permit
 /// @notice Extension to ERC721 that includes a permit function for signature based approvals
 interface IERC721Permit {
-    error NonceAlreadyUsed();
-
-    /// @notice The permit typehash used in the permit signature
-    /// @return The typehash for the permit
-    function PERMIT_TYPEHASH() external pure returns (bytes32);
+    error DeadlineExpired();
+    error NoSelfPermit();
+    error Unauthorized();
 
     /// @notice The domain separator used in the permit signature
     /// @return The domain seperator used in encoding of permit signature
@@ -18,10 +16,8 @@ interface IERC721Permit {
     /// @param spender The account that is being approved
     /// @param tokenId The ID of the token that is being approved for spending
     /// @param deadline The deadline timestamp by which the call must be mined for the approve to work
-    /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
-    /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
-    /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
-    function permit(address spender, uint256 tokenId, uint256 deadline, uint256 nonce, uint8 v, bytes32 r, bytes32 s)
+    /// @param signature Concatenated data from a valid secp256k1 signature from the holder, i.e. abi.encodePacked(r, s, v)
+    function permit(address spender, uint256 tokenId, uint256 deadline, uint256 nonce, bytes calldata signature)
         external
         payable;
 }

src/libraries/ERC721PermitHash.sol

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.24;
+
+library ERC721PermitHashLibrary {
+    /// @dev Value is equal to keccak256("Permit(address spender,uint256 tokenId,uint256 nonce,uint256 deadline)");
+    bytes32 constant PERMIT_TYPEHASH = 0x49ecf333e5b8c95c40fdafc95c1ad136e8914a8fb55e9dc8bb01eaa83a2df9ad;
+
+    function hash(address spender, uint256 tokenId, uint256 nonce, uint256 deadline) internal pure returns (bytes32) {
+        return keccak256(abi.encode(PERMIT_TYPEHASH, spender, tokenId, nonce, deadline));
+    }
+}