Verox Token - Audit Report

Summary

Verox Token Audit Report Verox intends to build an artificial intelligence investment manager for defi and crypto. The platform will partner with top crypto players to establish investment vehicles augmented by AI.

The application is still in development. For this audit, we analyzed Verox's token smart contract. We also analyzed the platform's staking contract here.

Features of the token contract:
  • No mint functions exist. After deployment, the total supply can only decrease.
  • A burn function exists, but it can only be called by the contract owner. This is intended to burn tokens left over in the presale
  • Ownership - Only the burn function is protected and can only be called by the contract owner. The owner can transfer ownership to any address.
  • Utilization of SafeMath to prevent overflows.
Audit Findings Summary
  • Overall, no serious issues were identified.
  • Date: November 28th, 2020


Date: November 28th, 2020
Vulnerability Category Notes Result
Arbitrary Storage Write N/A PASS
Arbitrary Jump N/A PASS
Delegate Call to Untrusted Contract N/A PASS
Dependence on Predictable Variables N/A PASS
Deprecated Opcodes N/A PASS
Ether Thief N/A PASS
Exceptions N/A PASS
External Calls N/A PASS
Integer Over/Underflow N/A PASS
Multiple Sends N/A PASS
Suicide N/A PASS
State Change External Calls N/A Pass
Unchecked Retval N/A PASS
User Supplied Assertion N/A PASS
Critical Solidity Compiler N/A PASS
Overall Contract Safety   PASS

ERC20 Token Graph

Multi-file Token


 ($) = payable function
 # = non-constant function
 
 Int = Internal
 Ext = External
 Pub = Public
 
 + [Lib] SafeMath 
    - [Int] mul
    - [Int] div
    - [Int] sub
    - [Int] add
    - [Int] mod

 +  Ownable 
    - [Pub]  #
    - [Pub] owner
    - [Pub] renounceOwnership #
       - modifiers: onlyOwner
    - [Pub] transferOwnership #
       - modifiers: onlyOwner

 +  VEROX (Ownable)
    - [Pub]  #
    - [Pub] totalSupply
    - [Pub] balanceOf
    - [Int] _transfer #
    - [Pub] transfer #
    - [Pub] burn #
       - modifiers: onlyOwner
    - [Pub] approve #
    - [Pub] transferFrom #
							

Click here to download the source code as a .sol file.


/**
 *Submitted for verification at Etherscan.io on 2020-10-31
*/

pragma solidity 0.6.0;

library SafeMath {
  /**
  * @dev Multiplies two unsigned integers, reverts on overflow.
  */
  function mul(uint256 a, uint256 b) internal pure returns (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-solidity/pull/522
    if (a == 0) {
        return 0;
    }

    uint256 c = a * b;
    require(c / a == b);

    return c;
  }

  /**
  * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
  */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // Solidity only automatically asserts when dividing by 0
    require(b > 0);
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
  * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b <= a);
    uint256 c = a - b;

    return c;
  }

  /**
  * @dev Adds two unsigned integers, reverts on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    require(c >= a);

    return c;
  }

  /**
  * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
  * reverts when dividing by zero.
  */
  function mod(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b != 0);
    return a % b;
  }
}

contract Ownable {
  address public _owner;

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  constructor () public {
    _owner = msg.sender;
    emit OwnershipTransferred(address(0), msg.sender);
  }

  function owner() public view returns (address) {
    return _owner;
  }

  modifier onlyOwner() {
    require(_owner == msg.sender, "Ownable: caller is not the owner");
    _;
  }

  function renounceOwnership() public virtual onlyOwner {
    emit OwnershipTransferred(_owner, address(0));
    _owner = address(0);
  }

  function transferOwnership(address newOwner) public virtual onlyOwner {
    require(newOwner != address(0), "Ownable: new owner is the zero address");
    emit OwnershipTransferred(_owner, newOwner);
    _owner = newOwner;
  }
}

contract VEROX is Ownable {
  using SafeMath for uint256;

  string public constant name = "Verox";
  string public constant symbol = "VRX";
  uint256 public constant decimals = 18;
  // the supply will not exceed 50,000 VRX
  uint256 private constant _maximumSupply = 50000 * 10 ** decimals;
  uint256 private constant _maximumPresaleBurnAmount = 0 * 10 ** decimals;
  uint256 public _presaleBurnTotal = 0;
  uint256 public _totalSupply;

  // events
  event Transfer(address indexed from, address indexed to, uint256 value);
  event Approval(address indexed owner, address indexed spender, uint256 value);

  // mappings
  mapping(address => uint256) public _balanceOf;
  mapping(address => mapping(address => uint256)) public allowance;

  constructor() public override {
    // transfer the entire supply to contract creator
    _owner = msg.sender;
    _totalSupply = _maximumSupply;
    _balanceOf[msg.sender] = _maximumSupply;
    emit Transfer(address(0x0), msg.sender, _maximumSupply);
  }

  function totalSupply () public view returns (uint256) {
    return _totalSupply; 
  }

  function balanceOf (address who) public view returns (uint256) {
    return _balanceOf[who];
  }

  // checks that the address is valid
  function _transfer(address _from, address _to, uint256 _value) internal {
    _balanceOf[_from] = _balanceOf[_from].sub(_value);
    _balanceOf[_to] = _balanceOf[_to].add(_value);
    emit Transfer(_from, _to, _value);
  }

  // transfer tokens
  function transfer(address _to, uint256 _value) public returns (bool success) {
    require(_balanceOf[msg.sender] >= _value);
    _transfer(msg.sender, _to, _value);
    return true;
  }

  // performs presale burn
  function burn (uint256 _burnAmount, bool _presaleBurn) public onlyOwner returns (bool success) {
    if (_presaleBurn) {
      require(_presaleBurnTotal.add(_burnAmount) <= _maximumPresaleBurnAmount);
      _presaleBurnTotal = _presaleBurnTotal.add(_burnAmount);
      _transfer(_owner, address(0), _burnAmount);
      _totalSupply = _totalSupply.sub(_burnAmount);
    } else {
      _transfer(_owner, address(0), _burnAmount);
      _totalSupply = _totalSupply.sub(_burnAmount);
    }
    return true;
  }

  // approve spend
  function approve(address _spender, uint256 _value) public returns (bool success) {
    require(_spender != address(0));
    allowance[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  // transfer from
  function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
    require(_value <= _balanceOf[_from]);
    require(_value <= allowance[_from][msg.sender]);
    allowance[_from][msg.sender] = allowance[_from][msg.sender].sub(_value);
    _transfer(_from, _to, _value);
    return true;
  }
}