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Fix allowance double spend exploit, testing is missing

This commit is contained in:
Oscar Martinez 2019-10-16 21:54:38 -05:00
parent 8d3497982d
commit d71d0e3c4c
2 changed files with 269 additions and 1 deletions
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268
DECA_ERC20_0.4.26.sol Normal file
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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 <p1r0@neetsec.com> and kaicudon <kaicudon@neetsec.com>
// ----------------------------------------------------------------------------
// ----------------------------------------------------------------------------
// 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);
}
}

2
DECA_IERC20_0.4.18.json
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@ -444,4 +444,4 @@
"name": "Approval", "name": "Approval",
"type": "event" "type": "event"
} }
] ]