A full decompilation and automatic security analysis of all contracts on the Ethereum and the Fantom blockchains. Updated hourly with new contracts uploaded to both networks. Analysis results by Dedaub.

Contract Library for the Ethereum and Fantom blockchains by Dedaub

itemType

token

from

identifier

amount

transfers

execute

magicValue

amounts

batchTransfers

executeBatch1155

standardTransfers

executeWithBatch1155

channel

isOpen

updateChannel

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7;

import { ConduitInterface } from "ConduitInterface.sol";

import { ConduitItemType } from "ConduitEnums.sol";

import { TokenTransferrer } from "TokenTransferrer.sol";

// prettier-ignore
import {
    ConduitTransfer,
    ConduitBatch1155Transfer
} from "ConduitStructs.sol";

import "ConduitConstants.sol";

/**
 * @title Conduit
 * @author 0age
 * @notice This contract serves as an originator for "proxied" transfers. Each
 *         conduit is deployed and controlled by a "conduit controller" that can
 *         add and remove "channels" or contracts that can instruct the conduit
 *         to transfer approved ERC20/721/1155 tokens. *IMPORTANT NOTE: each
 *         conduit has an owner that can arbitrarily add or remove channels, and
 *         a malicious or negligent owner can add a channel that allows for any
 *         approved ERC20/721/1155 tokens to be taken immediately — be extremely
 *         cautious with what conduits you give token approvals to!*
 */
contract Conduit is ConduitInterface, TokenTransferrer {
    // Set deployer as an immutable controller that can update channel statuses.
    address private immutable _controller;

    // Track the status of each channel.
    mapping(address => bool) private _channels;

    /**
     * @notice Ensure that the caller is currently registered as an open channel
     *         on the conduit.
     */
    modifier onlyOpenChannel() {
        // Utilize assembly to access channel storage mapping directly.
        assembly {
            // Write the caller to scratch space.
            mstore(ChannelKey_channel_ptr, caller())

            // Write the storage slot for _channels to scratch space.
            mstore(ChannelKey_slot_ptr, _channels.slot)

            // Derive the position in storage of _channels[msg.sender]
            // and check if the stored value is zero.
            if iszero(
                sload(keccak256(ChannelKey_channel_ptr, ChannelKey_length))
            ) {
                // The caller is not an open channel; revert with
                // ChannelClosed(caller). First, set error signature in memory.
                mstore(ChannelClosed_error_ptr, ChannelClosed_error_signature)

                // Next, set the caller as the argument.
                mstore(ChannelClosed_channel_ptr, caller())

                // Finally, revert, returning full custom error with argument.
                revert(ChannelClosed_error_ptr, ChannelClosed_error_length)
            }
        }

        // Continue with function execution.
        _;
    }

    /**
     * @notice In the constructor, set the deployer as the controller.
     */
    constructor() {
        // Set the deployer as the controller.
        _controller = msg.sender;
    }

    /**
     * @notice Execute a sequence of ERC20/721/1155 transfers. Only a caller
     *         with an open channel can call this function. Note that channels
     *         are expected to implement reentrancy protection if desired, and
     *         that cross-channel reentrancy may be possible if the conduit has
     *         multiple open channels at once. Also note that channels are
     *         expected to implement checks against transferring any zero-amount
     *         items if that constraint is desired.
     *
     * @param transfers The ERC20/721/1155 transfers to perform.
     *
     * @return magicValue A magic value indicating that the transfers were
     *                    performed successfully.
     */
    function execute(ConduitTransfer[] calldata transfers)
        external
        override
        onlyOpenChannel
        returns (bytes4 magicValue)
    {
        // Retrieve the total number of transfers and place on the stack.
        uint256 totalStandardTransfers = transfers.length;

        // Iterate over each transfer.
        for (uint256 i = 0; i < totalStandardTransfers; ) {
            // Retrieve the transfer in question and perform the transfer.
            _transfer(transfers[i]);

            // Skip overflow check as for loop is indexed starting at zero.
            unchecked {
                ++i;
            }
        }

        // Return a magic value indicating that the transfers were performed.
        magicValue = this.execute.selector;
    }

    /**
     * @notice Execute a sequence of batch 1155 item transfers. Only a caller
     *         with an open channel can call this function. Note that channels
     *         are expected to implement reentrancy protection if desired, and
     *         that cross-channel reentrancy may be possible if the conduit has
     *         multiple open channels at once. Also note that channels are
     *         expected to implement checks against transferring any zero-amount
     *         items if that constraint is desired.
     *
     * @param batchTransfers The 1155 batch item transfers to perform.
     *
     * @return magicValue A magic value indicating that the item transfers were
     *                    performed successfully.
     */
    function executeBatch1155(
        ConduitBatch1155Transfer[] calldata batchTransfers
    ) external override onlyOpenChannel returns (bytes4 magicValue) {
        // Perform 1155 batch transfers. Note that memory should be considered
        // entirely corrupted from this point forward.
        _performERC1155BatchTransfers(batchTransfers);

        // Return a magic value indicating that the transfers were performed.
        magicValue = this.executeBatch1155.selector;
    }

    /**
     * @notice Execute a sequence of transfers, both single ERC20/721/1155 item
     *         transfers as well as batch 1155 item transfers. Only a caller
     *         with an open channel can call this function. Note that channels
     *         are expected to implement reentrancy protection if desired, and
     *         that cross-channel reentrancy may be possible if the conduit has
     *         multiple open channels at once. Also note that channels are
     *         expected to implement checks against transferring any zero-amount
     *         items if that constraint is desired.
     *
     * @param standardTransfers The ERC20/721/1155 item transfers to perform.
     * @param batchTransfers    The 1155 batch item transfers to perform.
     *
     * @return magicValue A magic value indicating that the item transfers were
     *                    performed successfully.
     */
    function executeWithBatch1155(
        ConduitTransfer[] calldata standardTransfers,
        ConduitBatch1155Transfer[] calldata batchTransfers
    ) external override onlyOpenChannel returns (bytes4 magicValue) {
        // Retrieve the total number of transfers and place on the stack.
        uint256 totalStandardTransfers = standardTransfers.length;

        // Iterate over each standard transfer.
        for (uint256 i = 0; i < totalStandardTransfers; ) {
            // Retrieve the transfer in question and perform the transfer.
            _transfer(standardTransfers[i]);

            // Skip overflow check as for loop is indexed starting at zero.
            unchecked {
                ++i;
            }
        }

        // Perform 1155 batch transfers. Note that memory should be considered
        // entirely corrupted from this point forward aside from the free memory
        // pointer having the default value.
        _performERC1155BatchTransfers(batchTransfers);

        // Return a magic value indicating that the transfers were performed.
        magicValue = this.executeWithBatch1155.selector;
    }

    /**
     * @notice Open or close a given channel. Only callable by the controller.
     *
     * @param channel The channel to open or close.
     * @param isOpen  The status of the channel (either open or closed).
     */
    function updateChannel(address channel, bool isOpen) external override {
        // Ensure that the caller is the controller of this contract.
        if (msg.sender != _controller) {
            revert InvalidController();
        }

        // Ensure that the channel does not already have the indicated status.
        if (_channels[channel] == isOpen) {
            revert ChannelStatusAlreadySet(channel, isOpen);
        }

        // Update the status of the channel.
        _channels[channel] = isOpen;

        // Emit a corresponding event.
        emit ChannelUpdated(channel, isOpen);
    }

    /**
     * @dev Internal function to transfer a given ERC20/721/1155 item. Note that
     *      channels are expected to implement checks against transferring any
     *      zero-amount items if that constraint is desired.
     *
     * @param item The ERC20/721/1155 item to transfer.
     */
    function _transfer(ConduitTransfer calldata item) internal {
        // Determine the transfer method based on the respective item type.
        if (item.itemType == ConduitItemType.ERC20) {
            // Transfer ERC20 token. Note that item.identifier is ignored and
            // therefore ERC20 transfer items are potentially malleable — this
            // check should be performed by the calling channel if a constraint
            // on item malleability is desired.
            _performERC20Transfer(item.token, item.from, item.to, item.amount);
        } else if (item.itemType == ConduitItemType.ERC721) {
            // Ensure that exactly one 721 item is being transferred.
            if (item.amount != 1) {
                revert InvalidERC721TransferAmount();
            }

            // Transfer ERC721 token.
            _performERC721Transfer(
                item.token,
                item.from,
                item.to,
                item.identifier
            );
        } else if (item.itemType == ConduitItemType.ERC1155) {
            // Transfer ERC1155 token.
            _performERC1155Transfer(
                item.token,
                item.from,
                item.to,
                item.identifier,
                item.amount
            );
        } else {
            // Throw with an error.
            revert InvalidItemType();
        }
    }
}

Conduit.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7;

// error ChannelClosed(address channel)
uint256 constant ChannelClosed_error_signature = (
    0x93daadf200000000000000000000000000000000000000000000000000000000
);
uint256 constant ChannelClosed_error_ptr = 0x00;
uint256 constant ChannelClosed_channel_ptr = 0x4;
uint256 constant ChannelClosed_error_length = 0x24;

// For the mapping:
// mapping(address => bool) channels
// The position in storage for a particular account is:
// keccak256(abi.encode(account, channels.slot))
uint256 constant ChannelKey_channel_ptr = 0x00;
uint256 constant ChannelKey_slot_ptr = 0x20;
uint256 constant ChannelKey_length = 0x40;

ConduitConstants.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7;

enum ConduitItemType {
    NATIVE, // unused
    ERC20,
    ERC721,
    ERC1155
}

ConduitEnums.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7;

// prettier-ignore
import {
    ConduitTransfer,
    ConduitBatch1155Transfer
} from "ConduitStructs.sol";

/**
 * @title ConduitInterface
 * @author 0age
 * @notice ConduitInterface contains all external function interfaces, events,
 *         and errors for conduit contracts.
 */
interface ConduitInterface {
    /**
     * @dev Revert with an error when attempting to execute transfers using a
     *      caller that does not have an open channel.
     */
    error ChannelClosed(address channel);

    /**
     * @dev Revert with an error when attempting to update a channel to the
     *      current status of that channel.
     */
    error ChannelStatusAlreadySet(address channel, bool isOpen);

    /**
     * @dev Revert with an error when attempting to execute a transfer for an
     *      item that does not have an ERC20/721/1155 item type.
     */
    error InvalidItemType();

    /**
     * @dev Revert with an error when attempting to update the status of a
     *      channel from a caller that is not the conduit controller.
     */
    error InvalidController();

    /**
     * @dev Emit an event whenever a channel is opened or closed.
     *
     * @param channel The channel that has been updated.
     * @param open    A boolean indicating whether the conduit is open or not.
     */
    event ChannelUpdated(address indexed channel, bool open);

    /**
     * @notice Execute a sequence of ERC20/721/1155 transfers. Only a caller
     *         with an open channel can call this function.
     *
     * @param transfers The ERC20/721/1155 transfers to perform.
     *
     * @return magicValue A magic value indicating that the transfers were
     *                    performed successfully.
     */
    function execute(ConduitTransfer[] calldata transfers)
        external
        returns (bytes4 magicValue);

    /**
     * @notice Execute a sequence of batch 1155 transfers. Only a caller with an
     *         open channel can call this function.
     *
     * @param batch1155Transfers The 1155 batch transfers to perform.
     *
     * @return magicValue A magic value indicating that the transfers were
     *                    performed successfully.
     */
    function executeBatch1155(
        ConduitBatch1155Transfer[] calldata batch1155Transfers
    ) external returns (bytes4 magicValue);

    /**
     * @notice Execute a sequence of transfers, both single and batch 1155. Only
     *         a caller with an open channel can call this function.
     *
     * @param standardTransfers  The ERC20/721/1155 transfers to perform.
     * @param batch1155Transfers The 1155 batch transfers to perform.
     *
     * @return magicValue A magic value indicating that the transfers were
     *                    performed successfully.
     */
    function executeWithBatch1155(
        ConduitTransfer[] calldata standardTransfers,
        ConduitBatch1155Transfer[] calldata batch1155Transfers
    ) external returns (bytes4 magicValue);

    /**
     * @notice Open or close a given channel. Only callable by the controller.
     *
     * @param channel The channel to open or close.
     * @param isOpen  The status of the channel (either open or closed).
     */
    function updateChannel(address channel, bool isOpen) external;
}

ConduitInterface.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7;

import { ConduitItemType } from "ConduitEnums.sol";

struct ConduitTransfer {
    ConduitItemType itemType;
    address token;
    address from;
    address to;
    uint256 identifier;
    uint256 amount;
}

struct ConduitBatch1155Transfer {
    address token;
    address from;
    address to;
    uint256[] ids;
    uint256[] amounts;
}

ConduitStructs.sol

TokenTransferrer.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7;

/*
 * -------------------------- Disambiguation & Other Notes ---------------------
 *    - The term "head" is used as it is in the documentation for ABI encoding,
 *      but only in reference to dynamic types, i.e. it always refers to the
 *      offset or pointer to the body of a dynamic type. In calldata, the head
 *      is always an offset (relative to the parent object), while in memory,
 *      the head is always the pointer to the body. More information found here:
 *      https://docs.soliditylang.org/en/v0.8.14/abi-spec.html#argument-encoding
 *        - Note that the length of an array is separate from and precedes the
 *          head of the array.
 *
 *    - The term "body" is used in place of the term "head" used in the ABI
 *      documentation. It refers to the start of the data for a dynamic type,
 *      e.g. the first word of a struct or the first word of the first element
 *      in an array.
 *
 *    - The term "pointer" is used to describe the absolute position of a value
 *      and never an offset relative to another value.
 *        - The suffix "_ptr" refers to a memory pointer.
 *        - The suffix "_cdPtr" refers to a calldata pointer.
 *
 *    - The term "offset" is used to describe the position of a value relative
 *      to some parent value. For example, OrderParameters_conduit_offset is the
 *      offset to the "conduit" value in the OrderParameters struct relative to
 *      the start of the body.
 *        - Note: Offsets are used to derive pointers.
 *
 *    - Some structs have pointers defined for all of their fields in this file.
 *      Lines which are commented out are fields that are not used in the
 *      codebase but have been left in for readability.
 */

uint256 constant AlmostOneWord = 0x1f;
uint256 constant OneWord = 0x20;
uint256 constant TwoWords = 0x40;
uint256 constant ThreeWords = 0x60;

uint256 constant FreeMemoryPointerSlot = 0x40;
uint256 constant ZeroSlot = 0x60;
uint256 constant DefaultFreeMemoryPointer = 0x80;

uint256 constant Slot0x80 = 0x80;
uint256 constant Slot0xA0 = 0xa0;
uint256 constant Slot0xC0 = 0xc0;

// abi.encodeWithSignature("transferFrom(address,address,uint256)")
uint256 constant ERC20_transferFrom_signature = (
    0x23b872dd00000000000000000000000000000000000000000000000000000000
);
uint256 constant ERC20_transferFrom_sig_ptr = 0x0;
uint256 constant ERC20_transferFrom_from_ptr = 0x04;
uint256 constant ERC20_transferFrom_to_ptr = 0x24;
uint256 constant ERC20_transferFrom_amount_ptr = 0x44;
uint256 constant ERC20_transferFrom_length = 0x64; // 4 + 32 * 3 == 100

// abi.encodeWithSignature(
//     "safeTransferFrom(address,address,uint256,uint256,bytes)"
// )
uint256 constant ERC1155_safeTransferFrom_signature = (
    0xf242432a00000000000000000000000000000000000000000000000000000000
);
uint256 constant ERC1155_safeTransferFrom_sig_ptr = 0x0;
uint256 constant ERC1155_safeTransferFrom_from_ptr = 0x04;
uint256 constant ERC1155_safeTransferFrom_to_ptr = 0x24;
uint256 constant ERC1155_safeTransferFrom_id_ptr = 0x44;
uint256 constant ERC1155_safeTransferFrom_amount_ptr = 0x64;
uint256 constant ERC1155_safeTransferFrom_data_offset_ptr = 0x84;
uint256 constant ERC1155_safeTransferFrom_data_length_ptr = 0xa4;
uint256 constant ERC1155_safeTransferFrom_length = 0xc4; // 4 + 32 * 6 == 196
uint256 constant ERC1155_safeTransferFrom_data_length_offset = 0xa0;

// abi.encodeWithSignature(
//     "safeBatchTransferFrom(address,address,uint256[],uint256[],bytes)"
// )
uint256 constant ERC1155_safeBatchTransferFrom_signature = (
    0x2eb2c2d600000000000000000000000000000000000000000000000000000000
);

bytes4 constant ERC1155_safeBatchTransferFrom_selector = bytes4(
    bytes32(ERC1155_safeBatchTransferFrom_signature)
);

uint256 constant ERC721_transferFrom_signature = ERC20_transferFrom_signature;
uint256 constant ERC721_transferFrom_sig_ptr = 0x0;
uint256 constant ERC721_transferFrom_from_ptr = 0x04;
uint256 constant ERC721_transferFrom_to_ptr = 0x24;
uint256 constant ERC721_transferFrom_id_ptr = 0x44;
uint256 constant ERC721_transferFrom_length = 0x64; // 4 + 32 * 3 == 100

// abi.encodeWithSignature("NoContract(address)")
uint256 constant NoContract_error_signature = (
    0x5f15d67200000000000000000000000000000000000000000000000000000000
);
uint256 constant NoContract_error_sig_ptr = 0x0;
uint256 constant NoContract_error_token_ptr = 0x4;
uint256 constant NoContract_error_length = 0x24; // 4 + 32 == 36

// abi.encodeWithSignature(
//     "TokenTransferGenericFailure(address,address,address,uint256,uint256)"
// )
uint256 constant TokenTransferGenericFailure_error_signature = (
    0xf486bc8700000000000000000000000000000000000000000000000000000000
);
uint256 constant TokenTransferGenericFailure_error_sig_ptr = 0x0;
uint256 constant TokenTransferGenericFailure_error_token_ptr = 0x4;
uint256 constant TokenTransferGenericFailure_error_from_ptr = 0x24;
uint256 constant TokenTransferGenericFailure_error_to_ptr = 0x44;
uint256 constant TokenTransferGenericFailure_error_id_ptr = 0x64;
uint256 constant TokenTransferGenericFailure_error_amount_ptr = 0x84;

// 4 + 32 * 5 == 164
uint256 constant TokenTransferGenericFailure_error_length = 0xa4;

// abi.encodeWithSignature(
//     "BadReturnValueFromERC20OnTransfer(address,address,address,uint256)"
// )
uint256 constant BadReturnValueFromERC20OnTransfer_error_signature = (
    0x9889192300000000000000000000000000000000000000000000000000000000
);
uint256 constant BadReturnValueFromERC20OnTransfer_error_sig_ptr = 0x0;
uint256 constant BadReturnValueFromERC20OnTransfer_error_token_ptr = 0x4;
uint256 constant BadReturnValueFromERC20OnTransfer_error_from_ptr = 0x24;
uint256 constant BadReturnValueFromERC20OnTransfer_error_to_ptr = 0x44;
uint256 constant BadReturnValueFromERC20OnTransfer_error_amount_ptr = 0x64;

// 4 + 32 * 4 == 132
uint256 constant BadReturnValueFromERC20OnTransfer_error_length = 0x84;

uint256 constant ExtraGasBuffer = 0x20;
uint256 constant CostPerWord = 3;
uint256 constant MemoryExpansionCoefficient = 0x200;

// Values are offset by 32 bytes in order to write the token to the beginning
// in the event of a revert
uint256 constant BatchTransfer1155Params_ptr = 0x24;
uint256 constant BatchTransfer1155Params_ids_head_ptr = 0x64;
uint256 constant BatchTransfer1155Params_amounts_head_ptr = 0x84;
uint256 constant BatchTransfer1155Params_data_head_ptr = 0xa4;
uint256 constant BatchTransfer1155Params_data_length_basePtr = 0xc4;
uint256 constant BatchTransfer1155Params_calldata_baseSize = 0xc4;

uint256 constant BatchTransfer1155Params_ids_length_ptr = 0xc4;

uint256 constant BatchTransfer1155Params_ids_length_offset = 0xa0;
uint256 constant BatchTransfer1155Params_amounts_length_baseOffset = 0xc0;
uint256 constant BatchTransfer1155Params_data_length_baseOffset = 0xe0;

uint256 constant ConduitBatch1155Transfer_usable_head_size = 0x80;

uint256 constant ConduitBatch1155Transfer_from_offset = 0x20;
uint256 constant ConduitBatch1155Transfer_ids_head_offset = 0x60;
uint256 constant ConduitBatch1155Transfer_amounts_head_offset = 0x80;
uint256 constant ConduitBatch1155Transfer_ids_length_offset = 0xa0;
uint256 constant ConduitBatch1155Transfer_amounts_length_baseOffset = 0xc0;
uint256 constant ConduitBatch1155Transfer_calldata_baseSize = 0xc0;

// Note: abbreviated version of above constant to adhere to line length limit.
uint256 constant ConduitBatchTransfer_amounts_head_offset = 0x80;

uint256 constant Invalid1155BatchTransferEncoding_ptr = 0x00;
uint256 constant Invalid1155BatchTransferEncoding_length = 0x04;
uint256 constant Invalid1155BatchTransferEncoding_selector = (
    0xeba2084c00000000000000000000000000000000000000000000000000000000
);

uint256 constant ERC1155BatchTransferGenericFailure_error_signature = (
    0xafc445e200000000000000000000000000000000000000000000000000000000
);
uint256 constant ERC1155BatchTransferGenericFailure_token_ptr = 0x04;
uint256 constant ERC1155BatchTransferGenericFailure_ids_offset = 0xc0;

TokenTransferrerConstants.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7;

/**
 * @title TokenTransferrerErrors
 */
interface TokenTransferrerErrors {
    /**
     * @dev Revert with an error when an ERC721 transfer with amount other than
     *      one is attempted.
     */
    error InvalidERC721TransferAmount();

    /**
     * @dev Revert with an error when attempting to fulfill an order where an
     *      item has an amount of zero.
     */
    error MissingItemAmount();

    /**
     * @dev Revert with an error when attempting to fulfill an order where an
     *      item has unused parameters. This includes both the token and the
     *      identifier parameters for native transfers as well as the identifier
     *      parameter for ERC20 transfers. Note that the conduit does not
     *      perform this check, leaving it up to the calling channel to enforce
     *      when desired.
     */
    error UnusedItemParameters();

    /**
     * @dev Revert with an error when an ERC20, ERC721, or ERC1155 token
     *      transfer reverts.
     *
     * @param token      The token for which the transfer was attempted.
     * @param from       The source of the attempted transfer.
     * @param to         The recipient of the attempted transfer.
     * @param identifier The identifier for the attempted transfer.
     * @param amount     The amount for the attempted transfer.
     */
    error TokenTransferGenericFailure(
        address token,
        address from,
        address to,
        uint256 identifier,
        uint256 amount
    );

    /**
     * @dev Revert with an error when a batch ERC1155 token transfer reverts.
     *
     * @param token       The token for which the transfer was attempted.
     * @param from        The source of the attempted transfer.
     * @param to          The recipient of the attempted transfer.
     * @param identifiers The identifiers for the attempted transfer.
     * @param amounts     The amounts for the attempted transfer.
     */
    error ERC1155BatchTransferGenericFailure(
        address token,
        address from,
        address to,
        uint256[] identifiers,
        uint256[] amounts
    );

    /**
     * @dev Revert with an error when an ERC20 token transfer returns a falsey
     *      value.
     *
     * @param token      The token for which the ERC20 transfer was attempted.
     * @param from       The source of the attempted ERC20 transfer.
     * @param to         The recipient of the attempted ERC20 transfer.
     * @param amount     The amount for the attempted ERC20 transfer.
     */
    error BadReturnValueFromERC20OnTransfer(
        address token,
        address from,
        address to,
        uint256 amount
    );

    /**
     * @dev Revert with an error when an account being called as an assumed
     *      contract does not have code and returns no data.
     *
     * @param account The account that should contain code.
     */
    error NoContract(address account);

    /**
     * @dev Revert with an error when attempting to execute an 1155 batch
     *      transfer using calldata not produced by default ABI encoding or with
     *      different lengths for ids and amounts arrays.
     */
    error Invalid1155BatchTransferEncoding();
}