From d71d0e3c4c4ec535c6899cff98bfed80f7ce2e83 Mon Sep 17 00:00:00 2001 From: Oscar Martinez Date: Wed, 16 Oct 2019 21:54:38 -0500 Subject: [PATCH] Fix allowance double spend exploit, testing is missing --- DECA_ERC20_0.4.26.sol | 268 ++++++++++++++++++++++++++++++++++++++++ DECA_IERC20_0.4.18.json | 2 +- 2 files changed, 269 insertions(+), 1 deletion(-) create mode 100644 DECA_ERC20_0.4.26.sol diff --git a/DECA_ERC20_0.4.26.sol b/DECA_ERC20_0.4.26.sol new file mode 100644 index 0000000..dda4528 --- /dev/null +++ b/DECA_ERC20_0.4.26.sol @@ -0,0 +1,268 @@ +pragma solidity 0.4.26; + +// ---------------------------------------------------------------------------- +// 'DECA' DEcentralized CArbon tokens - ITDE (initial token distribution event) +// +// Deployed to : 0xD9497a4ee4D9E6E73EC1126D2f7827DEA8A51154 +// Network : Ropsten +// Symbol : DECA +// Name : Decentralized Carbon tokens +// Total supply: Gazillion +// Decimals : 18 +// +// Enjoy. +// +// (c) by Moritz Neto & Daniel Bar with BokkyPooBah / Bok Consulting Pty Ltd Au 2017. The MIT Licence. +// fork and modifications to fix DECA's ICO needs by p1r0 and kaicudon +// ---------------------------------------------------------------------------- + +// ---------------------------------------------------------------------------- +// Safe maths +// ---------------------------------------------------------------------------- +contract SafeMath { + function safeAdd(uint a, uint b) internal pure returns (uint c) { + c = a + b; + require(c >= a); + } + function safeSub(uint a, uint b) internal pure returns (uint c) { + require(b <= a); + c = a - b; + } + function safeMul(uint a, uint b) internal pure returns (uint c) { + c = a * b; + require(a == 0 || c / a == b); + } + function safeDiv(uint a, uint b) internal pure returns (uint c) { + require(b > 0); + c = a / b; + } +} + +// ---------------------------------------------------------------------------- +// ERC Token Standard #20 Interface +// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md +// ---------------------------------------------------------------------------- +contract ERC20Interface { + function totalSupply() public constant returns (uint); + function balanceOf(address tokenOwner) public constant returns (uint balance); + function allowance(address tokenOwner, address spender) public constant returns (uint remaining); + function transfer(address to, uint tokens) public returns (bool success); + function approve(address spender, uint tokens) public returns (bool success); + function transferFrom(address from, address to, uint tokens) public returns (bool success); + + event Transfer(address indexed from, address indexed to, uint tokens); + event Approval(address indexed tokenOwner, address indexed spender, uint tokens); +} + +// ---------------------------------------------------------------------------- +// Contract function to receive approval and execute function in one call +// +// Borrowed from MiniMeToken +// ---------------------------------------------------------------------------- +contract ApproveAndCallFallBack { + function receiveApproval(address from, uint256 tokens, address token, bytes data) public; +} + +// ---------------------------------------------------------------------------- +// Owned contract +// ---------------------------------------------------------------------------- +contract Owned { + address public owner; + address public newOwner; + string public _CCDBAddress; + + event OwnershipTransferred(address indexed _from, address indexed _to); + + constructor () public { + owner = msg.sender; + } + + modifier onlyOwner { + require(msg.sender == owner); + _; + } + + function updateCCDBAddress(string CCDBAddress) public onlyOwner { + _CCDBAddress = CCDBAddress; + } + + function transferOwnership(address _newOwner) public onlyOwner { + newOwner = _newOwner; + } + + function acceptOwnership() public { + require(msg.sender == newOwner); + emit OwnershipTransferred(owner, newOwner); + owner = newOwner; + newOwner = address(0); + } +} + +// ---------------------------------------------------------------------------- +// ERC20 Token, with the addition of symbol, name and decimals and assisted +// token transfers +// ---------------------------------------------------------------------------- +contract DECAToken is ERC20Interface, Owned, SafeMath { + string public symbol = "DECA"; + string public name = "DEcentralized CArbon tokens"; + uint8 public decimals = 18; + uint public _totalSupply; + //for testing change weeks for hours... + uint public preICOEnds = now + 1 hours; + uint public bonus1Ends = now + 3 hours; + uint public bonus2Ends = now + 6 hours; + uint public endDate = now + 11 hours; + + mapping(address => uint) balances; + mapping(address => mapping(address => uint)) allowed; + + // ------------------------------------------------------------------------ + // Total supply: Get the total token supply + // ------------------------------------------------------------------------ + + function totalSupply() public constant returns (uint) { + return _totalSupply - balances[address(0)]; + } + + // ------------------------------------------------------------------------ + // Get the token balance for account `tokenOwner` + // ------------------------------------------------------------------------ + function balanceOf(address tokenOwner) public constant returns (uint balance) { + return balances[tokenOwner]; + } + + // ------------------------------------------------------------------------ + // Transfer the balance from token owner's account to `to` account + // - Owner's account must have sufficient balance to transfer + // - 0 value transfers are allowed + // ------------------------------------------------------------------------ + function transfer(address to, uint tokens) public returns (bool success) { + balances[msg.sender] = safeSub(balances[msg.sender], tokens); + balances[to] = safeAdd(balances[to], tokens); + emit Transfer(msg.sender, to, tokens); + return true; + } + + // ------------------------------------------------------------------------ + // Token owner can approve for `spender` to transferFrom(...) `tokens` + // from the token owner's account + // + // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md + // recommends that there are no checks for the approval double-spend attack + // as this should be implemented in user interfaces + // ------------------------------------------------------------------------ + function approve(address spender, uint tokens) public returns (bool success) { + // approve should only be called when setting an initial allowance, + // or when resetting it to zero. To increase and decrease it, use + // 'increaseApproval' and 'decreaseApproval' + if (allowed[msg.sender][spender] == 0 || tokens == 0){ + emit Approval(msg.sender, spender, tokens); + return true; + } + return false; + } + + /* + * approve should be called when allowed[spender] == 0. To increment + * allowed value is better to use this function to avoid 2 calls (and wait until + * the first transaction is mined) + */ + function increaseApproval (address spender, uint tokens) public returns (bool success){ + allowed[msg.sender][spender] = safeAdd(allowed[msg.sender][spender], tokens); + emit Approval(msg.sender, spender, allowed[msg.sender][spender]); + return true; + } + + function decreaseApproval (address spender, uint tokens) public returns (bool success) { + uint oldValue = allowed[msg.sender][spender]; + if (tokens > oldValue) { + allowed[msg.sender][spender] = 0; + } + else{ + allowed[msg.sender][spender] = safeSub(oldValue, tokens); + } + emit Approval(msg.sender, spender, allowed[msg.sender][spender]); + return true; + } + + // ------------------------------------------------------------------------ + // Transfer `tokens` from the `from` account to the `to` account + // + // The calling account must already have sufficient tokens approve(...)-d + // for spending from the `from` account and + // - From account must have sufficient balance to transfer + // - Spender must have sufficient allowance to transfer + // - 0 value transfers are allowed + // ------------------------------------------------------------------------ + function transferFrom(address from, address to, uint tokens) public returns (bool success) { + balances[from] = safeSub(balances[from], tokens); + allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens); + balances[to] = safeAdd(balances[to], tokens); + emit Transfer(from, to, tokens); + return true; + } + + // ------------------------------------------------------------------------ + // Returns the amount of tokens approved by the owner that can be + // transferred to the spender's account + // ------------------------------------------------------------------------ + function allowance(address tokenOwner, address spender) public constant returns (uint remaining) { + return allowed[tokenOwner][spender]; + } + + // ------------------------------------------------------------------------ + // Token owner can approve for `spender` to transferFrom(...) `tokens` + // from the token owner's account. The `spender` contract function + // `receiveApproval(...)` is then executed + // ------------------------------------------------------------------------ + function approveAndCall(address spender, uint tokens, bytes data) public returns (bool success) { + allowed[msg.sender][spender] = tokens; + emit Approval(msg.sender, spender, tokens); + ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data); + return true; + } + + // ------------------------------------------------------------------------ + // 1,000 DECA Tokens per 1 ETH + // ------------------------------------------------------------------------ + function () public payable { + require(now <= endDate); + uint tokens; + uint toOwner; + uint toSender; + uint divBy; + + divBy = 10; // division to get 10% + + if (now <= preICOEnds) { + tokens = msg.value * 2000; + } else if (now > preICOEnds && now <= bonus1Ends ) { + tokens = msg.value * 1500; + } else if (now > bonus1Ends && now <= bonus2Ends) { + tokens = msg.value * 1250; + } else { + tokens = msg.value * 1000; + } + toOwner = safeDiv(tokens, divBy); // divBy to get the percentage assigned to the contract owner (for exchange to Cabron Credits) + toSender = tokens; // tokens goes to sender + balances[msg.sender] = safeAdd(balances[msg.sender], toSender); + balances[owner] = safeAdd(balances[owner], toOwner); + _totalSupply = safeAdd(_totalSupply, safeAdd(toSender,toOwner)); + emit Transfer(address(0), msg.sender, toSender); + emit Transfer(address(0), owner, toOwner); + } + + //Close down the ICO and Claim the Ether. + function getETH() public onlyOwner { + require(now >= endDate ); + // transfer the ETH balance in the contract to the owner + owner.transfer(address(this).balance); + } + + // ------------------------------------------------------------------------ + // Owner can transfer out any accidentally sent ERC20 tokens + // ------------------------------------------------------------------------ + function transferAnyERC20Token(address tokenAddress, uint tokens) public onlyOwner returns (bool success) { + return ERC20Interface(tokenAddress).transfer(owner, tokens); + } +} \ No newline at end of file diff --git a/DECA_IERC20_0.4.18.json b/DECA_IERC20_0.4.18.json index 1fd9656..872e710 100644 --- a/DECA_IERC20_0.4.18.json +++ b/DECA_IERC20_0.4.18.json @@ -444,4 +444,4 @@ "name": "Approval", "type": "event" } -] +] \ No newline at end of file