Contract Source Code (Solidity Standard Json-Input format)

IDE

• Blockscan IDE

More Options

• Similar
• Sol2Uml
• Submit Audit
• Compare

// SPDX-FileCopyrightText: 2021 Lido <[email protected]>

// SPDX-License-Identifier: GPL-3.0

/* See contracts/COMPILERS.md */
pragma solidity 0.6.12;

import "@openzeppelin/contracts/drafts/ERC20Permit.sol";
import "./interfaces/IStETH.sol";

/**
 * @title StETH token wrapper with static balances.
 * @dev It's an ERC20 token that represents the account's share of the total
 * supply of stETH tokens. WstETH token's balance only changes on transfers,
 * unlike StETH that is also changed when oracles report staking rewards and
 * penalties. It's a "power user" token for DeFi protocols which don't
 * support rebasable tokens.
 *
 * The contract is also a trustless wrapper that accepts stETH tokens and mints
 * wstETH in return. Then the user unwraps, the contract burns user's wstETH
 * and sends user locked stETH in return.
 *
 * The contract provides the staking shortcut: user can send ETH with regular
 * transfer and get wstETH in return. The contract will send ETH to Lido submit
 * method, staking it and wrapping the received stETH.
 *
 */
contract WstETH is ERC20Permit {
    IStETH public stETH;

    /**
     * @param _stETH address of the StETH token to wrap
     */
    constructor(IStETH _stETH)
        public
        ERC20Permit("Wrapped liquid staked Ether 2.0")
        ERC20("Wrapped liquid staked Ether 2.0", "wstETH")
    {
        stETH = _stETH;
    }

    /**
     * @notice Exchanges stETH to wstETH
     * @param _stETHAmount amount of stETH to wrap in exchange for wstETH
     * @dev Requirements:
     *  - `_stETHAmount` must be non-zero
     *  - msg.sender must approve at least `_stETHAmount` stETH to this
     *    contract.
     *  - msg.sender must have at least `_stETHAmount` of stETH.
     * User should first approve _stETHAmount to the WstETH contract
     * @return Amount of wstETH user receives after wrap
     */
    function wrap(uint256 _stETHAmount) external returns (uint256) {
        require(_stETHAmount > 0, "wstETH: can't wrap zero stETH");
        uint256 wstETHAmount = stETH.getSharesByPooledEth(_stETHAmount);
        _mint(msg.sender, wstETHAmount);
        stETH.transferFrom(msg.sender, address(this), _stETHAmount);
        return wstETHAmount;
    }

    /**
     * @notice Exchanges wstETH to stETH
     * @param _wstETHAmount amount of wstETH to uwrap in exchange for stETH
     * @dev Requirements:
     *  - `_wstETHAmount` must be non-zero
     *  - msg.sender must have at least `_wstETHAmount` wstETH.
     * @return Amount of stETH user receives after unwrap
     */
    function unwrap(uint256 _wstETHAmount) external returns (uint256) {
        require(_wstETHAmount > 0, "wstETH: zero amount unwrap not allowed");
        uint256 stETHAmount = stETH.getPooledEthByShares(_wstETHAmount);
        _burn(msg.sender, _wstETHAmount);
        stETH.transfer(msg.sender, stETHAmount);
        return stETHAmount;
    }

    /**
    * @notice Shortcut to stake ETH and auto-wrap returned stETH
    */
    receive() external payable {
        uint256 shares = stETH.submit{value: msg.value}(address(0));
        _mint(msg.sender, shares);
    }

    /**
     * @notice Get amount of wstETH for a given amount of stETH
     * @param _stETHAmount amount of stETH
     * @return Amount of wstETH for a given stETH amount
     */
    function getWstETHByStETH(uint256 _stETHAmount) external view returns (uint256) {
        return stETH.getSharesByPooledEth(_stETHAmount);
    }

    /**
     * @notice Get amount of stETH for a given amount of wstETH
     * @param _wstETHAmount amount of wstETH
     * @return Amount of stETH for a given wstETH amount
     */
    function getStETHByWstETH(uint256 _wstETHAmount) external view returns (uint256) {
        return stETH.getPooledEthByShares(_wstETHAmount);
    }

    /**
     * @notice Get amount of stETH for a one wstETH
     * @return Amount of stETH for 1 wstETH
     */
    function stEthPerToken() external view returns (uint256) {
        return stETH.getPooledEthByShares(1 ether);
    }

    /**
     * @notice Get amount of wstETH for a one stETH
     * @return Amount of wstETH for a 1 stETH
     */
    function tokensPerStEth() external view returns (uint256) {
        return stETH.getSharesByPooledEth(1 ether);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        // Check the signature length
        if (signature.length != 65) {
            revert("ECDSA: invalid signature length");
        }

        // Divide the signature in r, s and v variables
        bytes32 r;
        bytes32 s;
        uint8 v;

        // ecrecover takes the signature parameters, and the only way to get them
        // currently is to use assembly.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            r := mload(add(signature, 0x20))
            s := mload(add(signature, 0x40))
            v := byte(0, mload(add(signature, 0x60)))
        }

        return recover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover-bytes32-bytes-} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        require(uint256(s) <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, "ECDSA: invalid signature 's' value");
        require(v == 27 || v == 28, "ECDSA: invalid signature 'v' value");

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        require(signer != address(0), "ECDSA: invalid signature");

        return signer;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * replicates the behavior of the
     * https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign[`eth_sign`]
     * JSON-RPC method.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
 *
 * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
 * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
 * they need in their contracts using a combination of `abi.encode` and `keccak256`.
 *
 * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
 * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
 * ({_hashTypedDataV4}).
 *
 * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
 * the chain id to protect against replay attacks on an eventual fork of the chain.
 *
 * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
 * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
 *
 * _Available since v3.4._
 */
abstract contract EIP712 {
    /* solhint-disable var-name-mixedcase */
    // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
    // invalidate the cached domain separator if the chain id changes.
    bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;
    uint256 private immutable _CACHED_CHAIN_ID;

    bytes32 private immutable _HASHED_NAME;
    bytes32 private immutable _HASHED_VERSION;
    bytes32 private immutable _TYPE_HASH;
    /* solhint-enable var-name-mixedcase */

    /**
     * @dev Initializes the domain separator and parameter caches.
     *
     * The meaning of `name` and `version` is specified in
     * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
     *
     * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
     * - `version`: the current major version of the signing domain.
     *
     * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
     * contract upgrade].
     */
    constructor(string memory name, string memory version) internal {
        bytes32 hashedName = keccak256(bytes(name));
        bytes32 hashedVersion = keccak256(bytes(version));
        bytes32 typeHash = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
        _HASHED_NAME = hashedName;
        _HASHED_VERSION = hashedVersion;
        _CACHED_CHAIN_ID = _getChainId();
        _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion);
        _TYPE_HASH = typeHash;
    }

    /**
     * @dev Returns the domain separator for the current chain.
     */
    function _domainSeparatorV4() internal view virtual returns (bytes32) {
        if (_getChainId() == _CACHED_CHAIN_ID) {
            return _CACHED_DOMAIN_SEPARATOR;
        } else {
            return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION);
        }
    }

    function _buildDomainSeparator(bytes32 typeHash, bytes32 name, bytes32 version) private view returns (bytes32) {
        return keccak256(
            abi.encode(
                typeHash,
                name,
                version,
                _getChainId(),
                address(this)
            )
        );
    }

    /**
     * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
     * function returns the hash of the fully encoded EIP712 message for this domain.
     *
     * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
     *
     * ```solidity
     * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
     *     keccak256("Mail(address to,string contents)"),
     *     mailTo,
     *     keccak256(bytes(mailContents))
     * )));
     * address signer = ECDSA.recover(digest, signature);
     * ```
     */
    function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x01", _domainSeparatorV4(), structHash));
    }

    function _getChainId() private view returns (uint256 chainId) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        // solhint-disable-next-line no-inline-assembly
        assembly {
            chainId := chainid()
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.5 <0.8.0;

import "../token/ERC20/ERC20.sol";
import "./IERC20Permit.sol";
import "../cryptography/ECDSA.sol";
import "../utils/Counters.sol";
import "./EIP712.sol";

/**
 * @dev Implementation 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.
 *
 * _Available since v3.4._
 */
abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {
    using Counters for Counters.Counter;

    mapping (address => Counters.Counter) private _nonces;

    // solhint-disable-next-line var-name-mixedcase
    bytes32 private immutable _PERMIT_TYPEHASH = keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");

    /**
     * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
     *
     * It's a good idea to use the same `name` that is defined as the ERC20 token name.
     */
    constructor(string memory name) internal EIP712(name, "1") {
    }

    /**
     * @dev See {IERC20Permit-permit}.
     */
    function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public virtual override {
        // solhint-disable-next-line not-rely-on-time
        require(block.timestamp <= deadline, "ERC20Permit: expired deadline");

        bytes32 structHash = keccak256(
            abi.encode(
                _PERMIT_TYPEHASH,
                owner,
                spender,
                value,
                _nonces[owner].current(),
                deadline
            )
        );

        bytes32 hash = _hashTypedDataV4(structHash);

        address signer = ECDSA.recover(hash, v, r, s);
        require(signer == owner, "ERC20Permit: invalid signature");

        _nonces[owner].increment();
        _approve(owner, spender, value);
    }

    /**
     * @dev See {IERC20Permit-nonces}.
     */
    function nonces(address owner) public view override returns (uint256) {
        return _nonces[owner].current();
    }

    /**
     * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view override returns (bytes32) {
        return _domainSeparatorV4();
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <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);
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../../utils/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name_, string memory symbol_) public {
        _name = name_;
        _symbol = symbol_;
        _decimals = 18;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal virtual {
        _decimals = decimals_;
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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 `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @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);
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../math/SafeMath.sol";

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath}
 * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never
 * directly accessed.
 */
library Counters {
    using SafeMath for uint256;

    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        // The {SafeMath} overflow check can be skipped here, see the comment at the top
        counter._value += 1;
    }

    function decrement(Counter storage counter) internal {
        counter._value = counter._value.sub(1);
    }
}

// SPDX-FileCopyrightText: 2021 Lido <[email protected]>

// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.6.12; // latest available for using OZ

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";


interface IStETH is IERC20 {
    function getPooledEthByShares(uint256 _sharesAmount) external view returns (uint256);

    function getSharesByPooledEth(uint256 _pooledEthAmount) external view returns (uint256);

    function submit(address _referral) external payable returns (uint256);
}

{
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "evmVersion": "istanbul",
  "outputSelection": {
    "*": {
      "*": [
        "evm.bytecode",
        "evm.deployedBytecode",
        "devdoc",
        "userdoc",
        "metadata",
        "abi"
      ]
    }
  },
  "libraries": {}
}

[{"inputs":[{"internalType":"contract IStETH","name":"_stETH","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"inputs":[],"name":"DOMAIN_SEPARATOR","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"_wstETHAmount","type":"uint256"}],"name":"getStETHByWstETH","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"_stETHAmount","type":"uint256"}],"name":"getWstETHByStETH","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"}],"name":"nonces","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"permit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"stETH","outputs":[{"internalType":"contract IStETH","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"stEthPerToken","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"tokensPerStEth","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"_wstETHAmount","type":"uint256"}],"name":"unwrap","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"_stETHAmount","type":"uint256"}],"name":"wrap","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"stateMutability":"payable","type":"receive"}]

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

0000000000000000000000003508a952176b3c15387c97be809eaffb1982176a

-----Decoded View---------------
Arg [0] : _stETH (address): 0x3508A952176b3c15387C97BE809eaffB1982176a

-----Encoded View---------------
1 Constructor Arguments found :
Arg [0] : 0000000000000000000000003508a952176b3c15387c97be809eaffb1982176a