// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/functionisContract(address account) internalviewreturns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in// construction, since the code is only stored at the end of the// constructor execution.uint256 size;
// solhint-disable-next-line no-inline-assemblyassembly { size :=extcodesize(account) }
return size >0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/functionsendValue(addresspayable recipient, uint256 amount) internal{
require(address(this).balance>= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success, ) = recipient.call{ value: amount }("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain`call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/functionfunctionCall(address target, bytesmemory data, stringmemory errorMessage) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/functionfunctionCallWithValue(address target, bytesmemory data, uint256 value) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/functionfunctionCallWithValue(address target, bytesmemory data, uint256 value, stringmemory errorMessage) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory returndata) = target.call{ value: value }(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/functionfunctionStaticCall(address target, bytesmemory data, stringmemory errorMessage) internalviewreturns (bytesmemory) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/functionfunctionDelegateCall(address target, bytesmemory data, stringmemory errorMessage) internalreturns (bytesmemory) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function_verifyCallResult(bool success, bytesmemory returndata, stringmemory errorMessage) privatepurereturns(bytesmemory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assembly// solhint-disable-next-line no-inline-assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
Contract Source Code
File 2 of 9: Context.sol
// SPDX-License-Identifier: MITpragmasolidity ^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 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.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691returnmsg.data;
}
}
Contract Source Code
File 3 of 9: IERC20.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @dev Returns the amount of tokens in existence.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/functionbalanceOf(address account) externalviewreturns (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.
*/functiontransfer(address recipient, uint256 amount) externalreturns (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.
*/functionallowance(address owner, address spender) externalviewreturns (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.
*/functionapprove(address spender, uint256 amount) externalreturns (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.
*/functiontransferFrom(address sender, address recipient, uint256 amount) externalreturns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/eventTransfer(addressindexedfrom, addressindexed 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.
*/eventApproval(addressindexed owner, addressindexed spender, uint256 value);
}
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"@openzeppelin/contracts/utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/abstractcontractOwnableisContext{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/constructor (address owner) {
_owner = owner;
emit OwnershipTransferred(address(0), owner);
}
/**
* @dev Returns the address of the current owner.
*/functionowner() publicviewvirtualreturns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/modifieronlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/functionrenounceOwnership() publicvirtualonlyOwner{
emit OwnershipTransferred(_owner, address(0));
_owner =address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/functiontransferOwnership(address newOwner) publicvirtualonlyOwner{
require(newOwner !=address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
Contract Source Code
File 7 of 9: ReentrancyGuard.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/abstractcontractReentrancyGuard{
// Booleans are more expensive than uint256 or any type that takes up a full// word because each write operation emits an extra SLOAD to first read the// slot's contents, replace the bits taken up by the boolean, and then write// back. This is the compiler's defense against contract upgrades and// pointer aliasing, and it cannot be disabled.// The values being non-zero value makes deployment a bit more expensive,// but in exchange the refund on every call to nonReentrant will be lower in// amount. Since refunds are capped to a percentage of the total// transaction's gas, it is best to keep them low in cases like this one, to// increase the likelihood of the full refund coming into effect.uint256privateconstant _NOT_ENTERED =1;
uint256privateconstant _ENTERED =2;
uint256private _status;
constructor () {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/modifiernonReentrant() {
// On the first call to nonReentrant, _notEntered will be truerequire(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
Contract Source Code
File 8 of 9: SafeERC20.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"../IERC20.sol";
import"../../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/librarySafeERC20{
usingAddressforaddress;
functionsafeTransfer(IERC20 token, address to, uint256 value) internal{
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
functionsafeTransferFrom(IERC20 token, addressfrom, address to, uint256 value) internal{
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/functionsafeApprove(IERC20 token, address spender, uint256 value) internal{
// safeApprove should only be called when setting an initial allowance,// or when resetting it to zero. To increase and decrease it, use// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'// solhint-disable-next-line max-line-lengthrequire((value ==0) || (token.allowance(address(this), spender) ==0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
functionsafeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal{
uint256 newAllowance = token.allowance(address(this), spender) + value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
functionsafeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal{
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/function_callOptionalReturn(IERC20 token, bytesmemory data) private{
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that// the target address contains contract code and also asserts for success in the low-level call.bytesmemory returndata =address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length>0) { // Return data is optional// solhint-disable-next-line max-line-lengthrequire(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
Contract Source Code
File 9 of 9: SaleDutch.sol
//SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"@openzeppelin/contracts/security/ReentrancyGuard.sol";
import"@openzeppelin/contracts/token/ERC20/IERC20.sol";
import"@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import"./utils/Ownable.sol";
import"./interfaces/IVoters.sol";
import"./interfaces/IERC677Receiver.sol";
contractSaleDutchisOwnable, ReentrancyGuard, IERC677Receiver{
usingSafeERC20forIERC20;
// Information of each user's participationstructUserInfo {
// How many tokens the user has provideduint amount;
// Wether this user has already claimed their share of tokens, defaults to falsebool claimedTokens;
}
// The raising token
IERC20 public paymentToken;
// The offering token
IERC20 public offeringToken;
// The time (unix seconds) when sale startsuintpublic startTime;
// The time (unix security) when sale endsuintpublic endTime;
// Price to start the sale at (offeringToken per 1e18 of paymentToken)uintpublic startPrice;
// Reserve price (as amount per 1e18 of token invested)uintpublic endPrice;
// Amount of tokens offered for saleuintpublic offeringAmount;
// Maximum a user can contributeuintpublic perUserCap;
// Voting token minimum balance to participateuintpublic votingMinimum;
// Voting token address
IVoters public votingToken;
// Voting token snapshot id to use for balances (optional)uintpublic votingSnapshotId;
// Wether deposits are pausedboolpublic paused;
// Wether the sale is finalizedboolpublic finalized;
// Total amount of raising tokens that have already been raiseduintpublic totalAmount;
// User's participation infomapping(address=> UserInfo) public userInfo;
// Participants listaddress[] public addressList;
eventDeposit(addressindexed user, uint amount);
eventHarvestTokens(addressindexed user, uint amount);
eventHarvestRefund(addressindexed user, uint amount);
constructor(address _paymentToken,
address _offeringToken,
uint _startTime,
uint _endTime,
uint _startPrice,
uint _endPrice,
uint _offeringAmount,
uint _perUserCap,
address _owner
) Ownable(_owner) {
paymentToken = IERC20(_paymentToken);
offeringToken = IERC20(_offeringToken);
startTime = _startTime;
endTime = _endTime;
startPrice = _startPrice;
endPrice = _endPrice;
offeringAmount = _offeringAmount;
perUserCap = _perUserCap;
require(_paymentToken != _offeringToken, 'payment != offering');
require(_startTime >block.timestamp, 'start > now');
require(_startTime < _endTime, 'start < end');
require(_startTime <10000000000, 'start time not unix');
require(_endTime <10000000000, 'start time not unix');
require(_startPrice >0, 'start price > 0');
require(_endPrice >0, 'end price > 0');
require(_offeringAmount >0, 'offering amount > 0');
}
functionconfigureVotingToken(uint minimum, address token, uint snapshotId) publiconlyOwner{
votingMinimum = minimum;
votingToken = IVoters(token);
votingSnapshotId = snapshotId;
}
functiontogglePaused() publiconlyOwner{
paused =!paused;
}
functionfinalize() public{
require(msg.sender== owner() ||block.timestamp> endTime +7days, 'no allowed');
finalized =true;
}
functiongetAddressListLength() externalviewreturns (uint) {
return addressList.length;
}
functiongetParams() externalviewreturns (uint, uint, uint, uint, uint, uint, uint, uint, uint, bool, bool) {
return (startTime, endTime, startPrice, endPrice,
offeringAmount, perUserCap, totalAmount,
currentPrice(), clearingPrice(), paused, finalized);
}
functionpriceChange() publicviewreturns (uint) {
return (startPrice - endPrice) / (endTime - startTime);
}
functioncurrentPrice() publicviewreturns (uint) {
if (block.timestamp<= startTime) return startPrice;
if (block.timestamp>= endTime) return endPrice;
return startPrice - ((block.timestamp- startTime) * priceChange());
}
functiontokenPrice() publicviewreturns (uint) {
return (totalAmount *1e18) / offeringAmount;
}
functionclearingPrice() publicviewreturns (uint) {
if (tokenPrice() > currentPrice()) return tokenPrice();
return currentPrice();
}
functionsaleSuccessful() publicviewreturns (bool) {
return tokenPrice() >= clearingPrice();
}
functioncommitmentSize(uint amount) publicviewreturns (uint) {
uint max = (offeringAmount * clearingPrice()) /1e18;
if (totalAmount + amount > max) {
return max - totalAmount;
}
return amount;
}
function_deposit(address user, uint amount) privatenonReentrant{
require(!paused, 'paused');
require(block.timestamp>= startTime &&block.timestamp<= endTime, 'sale not active');
require(amount >0, 'need amount > 0');
require(perUserCap ==0|| amount <= perUserCap, 'over per user cap');
require(userInfo[user].amount ==0, 'already participated');
if (votingMinimum >0) {
if (votingSnapshotId ==0) {
require(votingToken.balanceOf(user) >= votingMinimum, "under minimum locked");
} else {
require(votingToken.balanceOfAt(user, votingSnapshotId) >= votingMinimum, "under minimum locked");
}
}
uint cappedAmount = commitmentSize(amount);
require(cappedAmount >0, 'sale fully commited');
// Refund user's overpaymentif (amount - cappedAmount >0) {
paymentToken.transfer(user, amount - cappedAmount);
}
addressList.push(user);
userInfo[user].amount = cappedAmount;
totalAmount += cappedAmount;
emit Deposit(user, cappedAmount);
}
functiondeposit(uint amount) external{
_transferFrom(msg.sender, amount);
_deposit(msg.sender, amount);
}
functiononTokenTransfer(address user, uint amount, bytescalldata _data) externaloverride{
require(msg.sender==address(paymentToken), "onTokenTransfer: not paymentToken");
_deposit(user, amount);
}
functionharvestTokens() publicnonReentrant{
require(!paused, 'paused');
require(block.timestamp> endTime, 'sale not ended');
if (saleSuccessful()) {
require(finalized, 'not finalized');
require(userInfo[msg.sender].amount >0, 'have you participated?');
require(!userInfo[msg.sender].claimedTokens, 'already claimed');
uint amount = getOfferingAmount(msg.sender);
require(amount >0, 'nothing to claim');
offeringToken.safeTransfer(msg.sender, amount);
userInfo[msg.sender].claimedTokens =true;
emit HarvestTokens(msg.sender, amount);
} else {
uint amount = userInfo[msg.sender].amount;
userInfo[msg.sender].amount =0;
paymentToken.safeTransfer(msg.sender, amount);
emit HarvestRefund(msg.sender, amount);
}
}
// Amount of offering token a user will receivefunctiongetOfferingAmount(address _user) publicviewreturns (uint) {
return (userInfo[_user].amount * offeringAmount) / totalAmount;
}
functionwithdrawToken(address token, uint amount) publiconlyOwner{
IERC20(token).safeTransfer(msg.sender, amount);
}
function_transferFrom(addressfrom, uint amount) private{
uint balanceBefore = paymentToken.balanceOf(address(this));
paymentToken.safeTransferFrom(from, address(this), amount);
uint balanceAfter = paymentToken.balanceOf(address(this));
require(balanceAfter - balanceBefore == amount, "_transferFrom: balance change does not match amount");
}
}