问题

我已经创建了ERC20合同，将其编译在Remix中，并部署到Sepolia测试网。如何使该合同只能从适当的地址发送代币，不允许其他地址发送？在此先行致谢。

以下是合同代码：

pragma solidity ^0.4.24;

// 安全数学接口

contract SafeMath {

    function safeAdd(uint a, uint b) public pure returns (uint c) {
        c = a + b;
        require(c >= a);
    }

    function safeSub(uint a, uint b) public pure returns (uint c) {
        require(b <= a);
        c = a - b;
    }

    function safeMul(uint a, uint b) public pure returns (uint c) {
        c = a * b;
        require(a == 0 || c / a == b);
    }

    function safeDiv(uint a, uint b) public pure returns (uint c) {
        require(b > 0);
        c = a / b;
    }
}

// ERC20代币标准接口

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);
}

// 接收批准并执行函数的合同功能

contract ApproveAndCallFallBack {
    function receiveApproval(address from, uint256 tokens, address token, bytes data) public;
}

// 实际代币合同

contract Tether is ERC20Interface, SafeMath {
    string public symbol;
    string public name;
    uint8 public decimals;
    uint public _totalSupply;

    mapping(address => uint) balances;
    mapping(address => mapping(address => uint)) allowed;

    constructor() public {
        symbol = "USDT";
        name = "Tether";
        decimals = 6;
        _totalSupply = 1000000000000000;
        balances[0xC6AE84c5275E47F9607254Bbc4937fCCbA72B3E5] = _totalSupply;
        emit Transfer(address(0), 0xC6AE84c5275E47F9607254Bbc4937fCCbA72B3E5, _totalSupply);
    }

    function totalSupply() public constant returns (uint) {
        return _totalSupply - balances[address(0)];
    }

    function balanceOf(address tokenOwner) public constant returns (uint balance) {
        return balances[tokenOwner];
    }

    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;
    }

    function approve(address spender, uint tokens) public returns (bool success) {
        allowed[msg.sender][spender] = tokens;
        emit Approval(msg.sender, spender, tokens);
        return true;
    }

    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;
    }

    function allowance(address tokenOwner, address spender) public constant returns (uint remaining) {
        return allowed[tokenOwner][spender];
    }

    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;
    }

    function () public payable {
        revert();
    }
}

你尝试重写approve函数，但并没有达到你的预期目标。代币仍然可以从任何地址发送。如果你想要限制只有特定地址可以发送代币，你需要在transfer和transferFrom函数中添加适当的权限检查。你可以在这两个函数的开头加入条件来验证msg.sender是否是允许的地址。如果不是允许的地址，你可以选择拒绝转账或采取其他适当的措施。

英文:

I've created the ERC20 contract, compiled it in Remix and deployed to Sepolia testnet.
How can I make this contract to send tokens from an appropriate addresses only. Other addresses should not be allowed to send. Thanks in advance.

Here's the contract code:

pragma solidity ^0.4.24;
//Safe Math Interface
contract SafeMath {
function safeAdd(uint a, uint b) public pure returns (uint c) {
c = a + b;
require(c &gt;= a);
}
function safeSub(uint a, uint b) public pure returns (uint c) {
require(b &lt;= a);
c = a - b;
}
function safeMul(uint a, uint b) public pure returns (uint c) {
c = a * b;
require(a == 0 || c / a == b);
}
function safeDiv(uint a, uint b) public pure returns (uint c) {
require(b &gt; 0);
c = a / b;
}
}
//ERC Token Standard #20 Interface
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
contract ApproveAndCallFallBack {
function receiveApproval(address from, uint256 tokens, address token, bytes data) public;
}
//Actual token contract
contract Tether is ERC20Interface, SafeMath {
string public symbol;
string public  name;
uint8 public decimals;
uint public _totalSupply;
mapping(address =&gt; uint) balances;
mapping(address =&gt; mapping(address =&gt; uint)) allowed;
constructor() public {
symbol = &quot;USDT&quot;;
name = &quot;Tether&quot;;
decimals = 6;
_totalSupply = 1000000000000000;
balances[0xC6AE84c5275E47F9607254Bbc4937fCCbA72B3E5] = _totalSupply;
emit Transfer(address(0), 0xC6AE84c5275E47F9607254Bbc4937fCCbA72B3E5, _totalSupply);
}
function totalSupply() public constant returns (uint) {
return _totalSupply  - balances[address(0)];
}
function balanceOf(address tokenOwner) public constant returns (uint balance) {
return balances[tokenOwner];
}
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;
}
function approve(address spender, uint tokens) public returns (bool success) {
allowed[msg.sender][spender] = tokens;
emit Approval(msg.sender, spender, tokens);
return true;
}
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;
}
function allowance(address tokenOwner, address spender) public constant returns (uint remaining) {
return allowed[tokenOwner][spender];
}
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;
}
function () public payable {
revert();
}
}

I tried to rewrite the approve function like this but it didn't work out. Tokens still can sent from any address.

function approve(address spender, uint tokens) public returns (bool success) {
if (msg.sender == address(0x...)) {
allowed[msg.sender][spender] = tokens;
emit Approval(msg.sender, spender, tokens);
return true;
} else {
allowed[msg.sender][spender] = 0;
emit Approval(msg.sender, spender, 0);
return false;
}
}

答案1

得分: 1

如果您希望仅对特定地址启用转账，那么您应该将 if-else 逻辑添加到 `transfer` 而不是 `approve` 中。

因此，您的代码应该类似于以下内容。

```js
function transfer(address to, uint tokens) public returns (bool success) {
   if (msg.sender == "specific-address") {
      balances[msg.sender] = safeSub(balances[msg.sender], tokens);
      balances[to] = safeAdd(balances[to], tokens);
      emit Transfer(msg.sender, to, tokens);
      return true;
   }

   return false;
}

这样，如果其他地址尝试转移代币，则将无法通过 transfer 进行转移。


<details>
<summary>英文:</summary>
If you like to enable the transfer only for certain addresses, then you should instead add the if-else logic not in `approve`, but instead in `transfer`.
So your code should look something like this.
```js
function transfer(address to, uint tokens) public returns (bool success) {
if (msg.sender == &quot;specific-address&quot;) {
balances[msg.sender] = safeSub(balances[msg.sender], tokens);
balances[to] = safeAdd(balances[to], tokens);
emit Transfer(msg.sender, to, tokens);
return true;
}
return false;
}

This way if other addresses try to transfer the token then it will fail to do so using transfer.

通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。

如何只允许从适当的地址发送代币？

问题

答案1

将Java 120字符的ECDSA公钥转换为130字符的以太坊地址。

Go Blockchain API：寻找值的开头时出现无效字符 ‘þ’。

如何修复 Solidity 中的 ‘Migrations hit an invalid opcode while deploying’ 错误？

Metamask not returning "code 4001 User rejected the request." when closing login popup in Chrome, but works in Edge

What's the correct way to type hint an empty list as a literal in python?

如何在Highcharts Gantt中更改本地化的星期名称

如何在同一个流中使用多个过滤器和映射函数？

如何使用Map/Set来将代码优化到O(n)？

.NET MAUI Android在GitHub Actions上构建失败，错误代码为1。

如何在Playwright视觉比较中屏蔽多个定位器？

在C++中，可以使用可变模板参数来检索类型的内部类型。

selenium.common.exceptions.StaleElementReferenceException: Message: stale element reference: stale element not found

Creating and opening a URL to log in to Website via Basic Auth with Robot Framework/Selenium (Python)

AG Grid 在上下文菜单中以大文本形式打开

发表评论