holder

spender

nonce

expiry

allowed

permit

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
pragma abicoder v1;

interface IDaiLikePermit {
    function permit(
        address holder,
        address spender,
        uint256 nonce,
        uint256 expiry,
        bool allowed,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}


IDaiLikePermit

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
pragma abicoder v1;

type Address is uint256;

library AddressLib {
    function get(Address a) internal pure returns (address) {
        return address(uint160(Address.unwrap(a)));
    }

    function getFlag(Address a, uint256 flag) internal pure returns (bool) {
        return (Address.unwrap(a) & flag) != 0;
    }

    function getUint32(Address a, uint256 offset) internal pure returns (uint32) {
        return uint32(Address.unwrap(a) >> offset);
    }

    function getUint64(Address a, uint256 offset) internal pure returns (uint64) {
        return uint64(Address.unwrap(a) >> offset);
    }
}


AddressLib

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
pragma abicoder v1;

/// @title Revert reason forwarder.
library RevertReasonForwarder {
    /// @dev Forwards latest externall call revert.
    function reRevert() internal pure {
        // bubble up revert reason from latest external call
        /// @solidity memory-safe-assembly
        assembly { // solhint-disable-line no-inline-assembly
            let ptr := mload(0x40)
            returndatacopy(ptr, 0, returndatasize())
            revert(ptr, returndatasize())
        }
    }
}


RevertReasonForwarder

ForceApproveFailed

SafeDecreaseAllowanceFailed

SafeIncreaseAllowanceFailed

SafePermitBadLength

SafeTransferFailed

SafeTransferFromFailed

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
pragma abicoder v1;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol";
import "../interfaces/IDaiLikePermit.sol";
import "../libraries/RevertReasonForwarder.sol";

/// @title Implements efficient safe methods for ERC20 interface.
library SafeERC20 {
    error SafeTransferFailed();
    error SafeTransferFromFailed();
    error ForceApproveFailed();
    error SafeIncreaseAllowanceFailed();
    error SafeDecreaseAllowanceFailed();
    error SafePermitBadLength();

    /// @dev Ensures method do not revert or return boolean `true`, admits call to non-smart-contract.
    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 amount
    ) internal {
        bytes4 selector = token.transferFrom.selector;
        bool success;
        /// @solidity memory-safe-assembly
        assembly { // solhint-disable-line no-inline-assembly
            let data := mload(0x40)

            mstore(data, selector)
            mstore(add(data, 0x04), from)
            mstore(add(data, 0x24), to)
            mstore(add(data, 0x44), amount)
            success := call(gas(), token, 0, data, 100, 0x0, 0x20)
            if success {
                switch returndatasize()
                case 0 {
                    success := gt(extcodesize(token), 0)
                }
                default {
                    success := and(gt(returndatasize(), 31), eq(mload(0), 1))
                }
            }
        }
        if (!success) revert SafeTransferFromFailed();
    }

    /// @dev Ensures method do not revert or return boolean `true`, admits call to non-smart-contract.
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        if (!_makeCall(token, token.transfer.selector, to, value)) {
            revert SafeTransferFailed();
        }
    }

    /// @dev If `approve(from, to, amount)` fails, try to `approve(from, to, 0)` before retry.
    function forceApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        if (!_makeCall(token, token.approve.selector, spender, value)) {
            if (
                !_makeCall(token, token.approve.selector, spender, 0) ||
                !_makeCall(token, token.approve.selector, spender, value)
            ) {
                revert ForceApproveFailed();
            }
        }
    }

    /// @dev Allowance increase with safe math check.
    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 allowance = token.allowance(address(this), spender);
        if (value > type(uint256).max - allowance) revert SafeIncreaseAllowanceFailed();
        forceApprove(token, spender, allowance + value);
    }

    /// @dev Allowance decrease with safe math check.
    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 allowance = token.allowance(address(this), spender);
        if (value > allowance) revert SafeDecreaseAllowanceFailed();
        forceApprove(token, spender, allowance - value);
    }

    /// @dev Calls either ERC20 or Dai `permit` for `token`, if unsuccessful forwards revert from external call.
    function safePermit(IERC20 token, bytes calldata permit) internal {
        if (!tryPermit(token, permit)) RevertReasonForwarder.reRevert();
    }

    function tryPermit(IERC20 token, bytes calldata permit) internal returns(bool) {
        if (permit.length == 32 * 7) {
            return _makeCalldataCall(token, IERC20Permit.permit.selector, permit);
        }
        if (permit.length == 32 * 8) {
            return _makeCalldataCall(token, IDaiLikePermit.permit.selector, permit);
        }
        revert SafePermitBadLength();
    }

    function _makeCall(
        IERC20 token,
        bytes4 selector,
        address to,
        uint256 amount
    ) private returns (bool success) {
        /// @solidity memory-safe-assembly
        assembly { // solhint-disable-line no-inline-assembly
            let data := mload(0x40)

            mstore(data, selector)
            mstore(add(data, 0x04), to)
            mstore(add(data, 0x24), amount)
            success := call(gas(), token, 0, data, 0x44, 0x0, 0x20)
            if success {
                switch returndatasize()
                case 0 {
                    success := gt(extcodesize(token), 0)
                }
                default {
                    success := and(gt(returndatasize(), 31), eq(mload(0), 1))
                }
            }
        }
    }

    function _makeCalldataCall(
        IERC20 token,
        bytes4 selector,
        bytes calldata args
    ) private returns (bool success) {
        /// @solidity memory-safe-assembly
        assembly { // solhint-disable-line no-inline-assembly
            let len := add(4, args.length)
            let data := mload(0x40)

            mstore(data, selector)
            calldatacopy(add(data, 0x04), args.offset, args.length)
            success := call(gas(), token, 0, data, len, 0x0, 0x20)
            if success {
                switch returndatasize()
                case 0 {
                    success := gt(extcodesize(token), 0)
                }
                default {
                    success := and(gt(returndatasize(), 31), eq(mload(0), 1))
                }
            }
        }
    }
}


SafeERC20

owner

value

Approval

from

Transfer

allowance

amount

approve

account

balanceOf

totalSupply

transfer

transferFrom

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}


IERC20

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}


settlement

index

reason

FailedExternalCall

OnlyOwner

OnlySettlement

token

rescueFunds

resolver

tokensAndAmounts

data

resolveOrders

// SPDX-License-Identifier: MIT

pragma solidity 0.8.17;

import "./libraries/TokensAndAmounts.sol";
import "./interfaces/IResolver.sol";
import "@1inch/solidity-utils/contracts/libraries/SafeERC20.sol";

contract ResolverExample is IResolver {
    error OnlyOwner();
    error OnlySettlement();
    error FailedExternalCall(uint256 index, bytes reason);

    using TokensAndAmounts for bytes;
    using SafeERC20 for IERC20;
    using AddressLib for Address;

    address private immutable _settlement;
    address private immutable _owner;

    constructor(address settlement) {
        _settlement = settlement;
        _owner = msg.sender;
    }

    function resolveOrders(address resolver, bytes calldata tokensAndAmounts, bytes calldata data) external {
        if (msg.sender != _settlement) revert OnlySettlement();
        if (resolver != _owner) revert OnlyOwner();

        if (data.length > 0) {
            (Address[] memory targets, bytes[] memory calldatas) = abi.decode(data, (Address[], bytes[]));
            for (uint256 i = 0; i < targets.length; ++i) {
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory reason) = targets[i].get().call(calldatas[i]);
                if (!success) revert FailedExternalCall(i, reason);
            }
        }

        TokensAndAmounts.Data[] calldata items = tokensAndAmounts.decode();
        for (uint256 i = 0; i < items.length; i++) {
            IERC20(items[i].token.get()).safeTransfer(msg.sender, items[i].amount);
        }
    }

    function rescueFunds(IERC20 token) external {
        require(msg.sender == _owner, "caller is not owner");
        token.safeTransfer(msg.sender, token.balanceOf(address(this)));
    }
}


ResolverExample

// SPDX-License-Identifier: MIT

pragma solidity 0.8.17;

interface IResolver {
    function resolveOrders(address resolver, bytes calldata tokensAndAmounts, bytes calldata data) external;
}


IResolver

// SPDX-License-Identifier: MIT

pragma solidity 0.8.17;

import "@1inch/solidity-utils/contracts/libraries/AddressLib.sol";

library TokensAndAmounts {
    struct Data {
        Address token;
        uint256 amount;
    }

    function decode(bytes calldata cd) internal pure returns(Data[] calldata decoded) {
        assembly {
            decoded.offset := cd.offset
            decoded.length := div(cd.length, 0x40)
        }
    }
}


TokensAndAmounts

The 1inch Network unites decentralized protocols whose synergy enables the most lucrative, fastest and protected operations in the DeFi space.

The 1inch Network unites decentralized protocols whose synergy enables the most lucrative, fastest and protected operations in the DeFi space.

Repo

Audit

Chains

Authors

Get Cookin'

Repo

Audit

Authors

Fusion Resolver example

Installation

Run Tests

Examples