PHP realizes the automatic anti-swiping function of email verification code

Title: PHP realizes the automatic anti-swiping function of email verification code

With the popularity of the Internet and the widespread use of applications, email verification codes have become a common feature of many websites and applications Commonly used verification methods. However, because the frequency of sending verification codes is too high, it will put additional burden on the server and can easily be used by malicious users to swipe SMS verification codes. In order to solve this problem, the automatic anti-swiping function of email verification codes can be implemented in PHP. This article will introduce how to use PHP to implement this function, and attach specific code examples.

1. Generate email verification code

First, we need to generate an email verification code. In PHP, you can use the random number function rand() to generate a random verification code of a specified length. The code example is as follows:

function generateEmailCode($length) {
    $code = '';
    $chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $charLength = strlen($chars);

    for ($i = 0; $i < $length; $i++) {
        $code .= $chars[rand(0, $charLength - 1)];
    }

    return $code;
}

In the above code, the generateEmailCode() function accepts a parameter length, which is used to specify the length of the generated verification code. Internally, the function uses the rand() function to generate random numbers and generates verification codes based on the specified character set. Finally, the generated verification code is returned.

2. Calculate the frequency of sending verification codes

In order to prevent users from frequently swiping verification codes, we need to calculate the frequency of sending verification codes. When implementing the automatic anti-swipe function, we can use the database to record the time when each email address sends a verification code, and calculate the time interval for sending verification codes. If the time interval is less than the set threshold, it will be judged as a brushing behavior and the verification code will be refused to be sent.

First, we need to create a database table to record the verification code sending time, including fields such as email address, sending time, etc. The code example is as follows:

CREATE TABLE `email_verification` (
    `email` varchar(255) NOT NULL,
    `send_time` datetime NOT NULL
);

Next, write a function checkEmailFrequency() for checking the frequency of sending verification codes. The code example is as follows:

function checkEmailFrequency($email, $threshold) {
    $conn = mysqli_connect('localhost', 'username', 'password', 'database');

    if (!$conn) {
        die('数据库连接失败');
    }

    $query = "SELECT send_time FROM email_verification WHERE email = '$email' ORDER BY send_time DESC LIMIT 1";
    $result = mysqli_query($conn, $query);
    $row = mysqli_fetch_assoc($result);

    if ($row) {
        $lastSendTime = strtotime($row['send_time']);
        $currentTime = time();
        $timeDiff = $currentTime - $lastSendTime;

        if ($timeDiff < $threshold) {
            return false;
        }
    }

    return true;
}

In the above code, the checkEmailFrequency() function accepts two parameters, which are the email address and the threshold. Inside the function, a database connection is first established, then the last sending time of a specific mailbox is queried, and the time interval is calculated. If the time interval is less than the threshold, return false to indicate the swiping behavior; otherwise, return true to allow the verification code to be sent.

3. Send the email verification code

When sending the email verification code, first call the checkEmailFrequency() function to check the frequency of sending the verification code. If true is returned, the verification code can be sent; otherwise, the verification code will not be sent and a corresponding error prompt will be given. The code example is as follows:

$email = 'user@example.com';
$threshold = 60; // 阈值设为60秒

if (checkEmailFrequency($email, $threshold)) {
    $verificationCode = generateEmailCode(6); // 生成6位验证码

    // 发送验证码的逻辑代码

    // 记录验证码的发送时间
    $conn = mysqli_connect('localhost', 'username', 'password', 'database');

    if (!$conn) {
        die('数据库连接失败');
    }

    $query = "INSERT INTO email_verification (email, send_time) VALUES ('$email', NOW())";
    mysqli_query($conn, $query);
} else {
    echo '验证码发送过于频繁，请稍后再试。';
}

In the above code, $email is the email address to which the verification code needs to be sent, and $threshold is the set threshold. First call the checkEmailFrequency() function to check the sending frequency. If true is returned, the verification code will be sent and the sending time will be recorded. Otherwise, an error message will be given.

4. Summary

Through the above steps, we have successfully implemented the automatic anti-swiping function for email verification codes in PHP. Through steps such as generating verification codes, calculating sending frequency, and sending verification codes, users are effectively prevented from abusing verification codes. At the same time, we also briefly introduce specific code examples to facilitate developers to use them quickly. I hope this article will help you understand how to implement the automatic anti-swiping function of email verification codes.

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