基于OpenZepplin上线交易所的安全token合约

因为代币合约的安全问题，造成好多交易所和持币公司被黑客利用漏洞攻击，造成大量的损失，所以现在很多交易所 对代币都会进行审核，审核不通过的代币则不允许上线。

OpenZepplin库是一个写只能合约的安全库，利用可以简化我们的开发，而且它内置了很多东西，包括安全等方面。

只是做交易代币的话，有两种方法部署可以通过交易所审查的加密代币，第一种只说方法（过程以前的教程有），对于大部分人我推荐第二种（方便，快捷不写代码，复制我整理的代码，按步骤操作就行）：

1.利用

使用OpenZeppelin对于智能合约开发会快速很多，安装truffle框架npminstallzeppelin-solidity安装，然后继承里面的已有的智能合约就可以了。

打开truffle框架，contrancts目录，穿件一个只能合约TetsCion.sol文件，

pragma solidity ^0.4.4;

import "../node_modules/_openzeppelin-solidity@1.9.0@openzeppelin-solidity/contracts/token/StandardToken.sol";（引入openzeppelin安全库合约）

contract NenmoCoin is StandardToken {

......（里面写合约内容）

}

}

如图：

truffle框架目录 （windows删除truffle.js文件）

node模块

openzeppelin库：

openzeppelin合约模块：

token合约文件：

里面有几种代币的合约，我们做erc20的合约

openzeppelin内置的安全的ERC20合约：

写合约的时候，为了防止漏洞可以参考里面的已经审查过得安全合约

剩下的就是撸合约代码，编译部署，用truffle还是开发比较快的（但是不利于迭代），但是如果想深入了解以太坊的话，建议用WEB3，进行编译部署，可以写一个属于自己的部署框架。

2.傻瓜式操作，按照步骤来就好：

1）打开remix在线编译器（怎么用我以前的教程里面有）：

https://ethereum.github.io/browser-solidity/

2）登录metamask钱包：

3）复制下面代码到remix编译器：

pragma solidity ^0.4.21;

/**

* @title SafeMath

* @dev Math operations with safety checks that throw on error

*/

library SafeMath {

/**

* @dev Multiplies two numbers, throws on overflow.

*/

function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {

if (a == 0) {

return 0;

}

c = a * b;

assert(c / a == b);

return c;

}

/**

* @dev Integer division of two numbers, truncating the quotient.

*/

function div(uint256 a, uint256 b) internal pure returns (uint256) {

// assert(b > 0); // Solidity automatically throws when dividing by 0

// uint256 c = a / b;

// assert(a == b * c + a % b); // There is no case in which this doesn't hold

return a / b;

}

/**

* @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).

*/

function sub(uint256 a, uint256 b) internal pure returns (uint256) {

assert(b

return a - b;

}

/**

* @dev Adds two numbers, throws on overflow.

*/

function add(uint256 a, uint256 b) internal pure returns (uint256 c) {

c = a + b;

assert(c >= a);

return c;

}

}

/**

* @title ERC20Basic

* @dev Simpler version of ERC20 interface

* @dev see https://github.com/ethereum/EIPs/issues/179

*/

contract ERC20Basic {

function totalSupply() public view returns (uint256);

function balanceOf(address who) public view returns (uint256);

function transfer(address to, uint256 value) public returns (bool);

event Transfer(address indexed from, address indexed to, uint256 value);

}

/**

* @title Basic token

* @dev Basic version of StandardToken, with no allowances.

*/

contract BasicToken is ERC20Basic {

using SafeMath for uint256;

mapping(address => uint256) balances;

uint256 totalSupply_;

/**

* @dev total number of tokens in existence

*/

function totalSupply() public view returns (uint256) {

return totalSupply_;

}

/**

* @dev transfer token for a specified address

* @param _to The address to transfer to.

* @param _value The amount to be transferred.

*/

function transfer(address _to, uint256 _value) public returns (bool) {

require(_to != address(0));

require(_value

balances[msg.sender] = balances[msg.sender].sub(_value);

balances[_to] = balances[_to].add(_value);

emit Transfer(msg.sender, _to, _value);

return true;

}

/**

* @dev Gets the balance of the specified address.

* @param _owner The address to query the the balance of.

* @return An uint256 representing the amount owned by the passed address.

*/

function balanceOf(address _owner) public view returns (uint256) {

return balances[_owner];

}

}

/**

* @title ERC20 interface

* @dev see https://github.com/ethereum/EIPs/issues/20

*/

contract ERC20 is ERC20Basic {

function allowance(address owner, address spender) public view returns (uint256);

function transferFrom(address from, address to, uint256 value) public returns (bool);

function approve(address spender, uint256 value) public returns (bool);

event Approval(address indexed owner, address indexed spender, uint256 value);

}

/**

* @title Standard ERC20 token

*

* @dev Implementation of the basic standard token.

* @dev https://github.com/ethereum/EIPs/issues/20

* @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol

*/

/**

* @title Standard ERC20 token

*

* @dev Implementation of the basic standard token.

* @dev https://github.com/ethereum/EIPs/issues/20

* @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol

*/

contract StandardToken is ERC20, BasicToken {

mapping (address => mapping (address => uint256)) internal allowed;

/**

* @dev Transfer tokens from one address to another

* @param _from address The address which you want to send tokens from

* @param _to address The address which you want to transfer to

* @param _value uint256 the amount of tokens to be transferred

*/

function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {

require(_to != address(0));

require(_value

require(_value

balances[_from] = balances[_from].sub(_value);

balances[_to] = balances[_to].add(_value);

allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);

emit Transfer(_from, _to, _value);

return true;

}

/**

* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.

*

* 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

* @param _spender The address which will spend the funds.

* @param _value The amount of tokens to be spent.

*/

function approve(address _spender, uint256 _value) public returns (bool) {

allowed[msg.sender][_spender] = _value;

emit Approval(msg.sender, _spender, _value);

return true;

}

/**

* @dev Function to check the amount of tokens that an owner allowed to a spender.

* @param _owner address The address which owns the funds.

* @param _spender address The address which will spend the funds.

* @return A uint256 specifying the amount of tokens still available for the spender.

*/

function allowance(address _owner, address _spender) public view returns (uint256) {

return allowed[_owner][_spender];

}

/**

* @dev Increase the amount of tokens that an owner allowed to a spender.

*

* 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)

* From MonolithDAO Token.sol

* @param _spender The address which will spend the funds.

* @param _addedValue The amount of tokens to increase the allowance by.

*/

function increaseApproval(address _spender, uint _addedValue) public returns (bool) {

allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);

emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);

return true;

}

/**

* @dev Decrease the amount of tokens that an owner allowed to a spender.

*

* approve should be called when allowed[_spender] == 0. To decrement

* allowed value is better to use this function to avoid 2 calls (and wait until

* the first transaction is mined)

* From MonolithDAO Token.sol

* @param _spender The address which will spend the funds.

* @param _subtractedValue The amount of tokens to decrease the allowance by.

*/

function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {

uint oldValue = allowed[msg.sender][_spender];

if (_subtractedValue > oldValue) {

allowed[msg.sender][_spender] = 0;

} else {

allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);

}

emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);

return true;

}

}

contract TestCoin is StandardToken {

string public name = "TestCoin";

string public symbol = "TTB";

uint8 public decimals = 18;

uint256 public totalSupply;

function TestCoin() public{

totalSupply = 100000000* 10 ** uint256(decimals);

balances[msg.sender] = 100000000 * 10 ** uint256(decimals);

}

}

PS：最下的name symbol 和totalSupply分别对应，数字货币的名称、符号和数量，根据需求自定义修改，至于自动兑换、管理冻结等功能可参考我以前的教程，都有

4.选择合约名称，点击create部署

有很多个合约，但是TestCoin继承了上面的所有合约

5）matemask会弹出是否部署，但是submit提交：

7.显示如下，说明已经部署到主链上：

红圈为我们创建的token代币合约地址

8.你部署合约的那个账户，现在已经有的你部署的代币数量，可以去进行流通交易了，我部署TTB代币的数量是1亿，转了8888给其他账户了，所以剩下这么多

9.去验证你的合约，属于你自己，怎么验证参考以前的教程，现在你已经有了一个可以上线到交易所的安全代币，go！！