Summarize thinkphp's techniques for implementing front-end and back-end separation verification codes

thinkphp is a very convenient PHP framework that is widely used when developing websites and web applications. In this framework, front-end and back-end separation has become a popular development method. If you are using thinkphp and are looking for a way to implement verification codes, then this article will provide you with some tips on how to implement front-end and back-end separation verification codes in thinkphp.

1. The role of verification code

In the Internet era, we often use verification codes to enhance security. Implementing the verification code function can help us:

1. Prevent robot attacks: The verification code can detect whether it is a human operation to reduce attacks by malicious robots and hackers.
2. Improve security: Verification codes can strengthen permission control, ensure the authenticity of user identities, and protect servers and websites from unnecessary attacks.
3. Improve user experience: Verification code can effectively prevent users from losing interest due to continuous illegible characters.

2. Front-end verification code implementation

In the process of front-end implementation of verification code, we need the following main steps:

1. Determine the verification code Type: Verification codes are usually divided into character verification codes and graphic verification codes. Design with user experience and security in mind.
2. Draw verification code graphics: Use Canvas or other technologies to draw the verification code onto the front-end page. We can use the HTML5 Canvas element to customize the font, size, color, etc. of the verification code.
3. Get user input: Usually, we need to verify user input with the verification code generated by the server. We can use JavaScript and Ajax technology to get the input and send it to the server side.
4. Verification verification code: Verify user input on the server side. If an API interface is provided, the interface will return information such as verification success or failure to the client.

By using these technologies, users can obtain verification codes at the front desk to avoid automated malicious access or attacks.

3. Back-end verification code implementation

To implement verification code in thinkphp, we usually pay attention to the following aspects:

1. Create a verification code controller

You can place the verification code controller in the backend directory. The function of the controller is to handle the generation and verification of verification codes. In the controller, the following methods are usually included:

• generateCode: Generate a verification code and store the verification code in the Session.
• verifyCode: Verify whether the verification code entered by the user is correct.
• getCode: Returns the verification code stored in Session.

2. Generate verification code

When generating the verification code, we can use the GD library to generate the image, and then output the image and save the image. The result of the verification code is sent to the client. The following is a sample code:

public function generateCode($width=80,$height=22,$verifyName=''){
    //生成一个4位的随机字符串
    $code = '';
    $chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    for($i=0;$i<4;$i++){
        $code .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
    }
    //将验证码存储到session中
    if($verifyName){
        session($verifyName, $code);
    }else{
        session('verify_code', $code);
    }

    //生成验证码图像
    $img = imagecreate($width,$height);
    //背景色
    imagecolorallocate($img, 102,102,102);
    //字体颜色
    $color = imagecolorallocate($img, 255, 255, 255);
    //生成干扰线
    for($i=0;$i<5;$i++){
        imageline($img,mt_rand(0,$width/2),mt_rand(0,$height/2),mt_rand($width/2,$width),mt_rand($height/2,$height),$color);
    }
    //将验证码绘制到图像上
    imagefttext($img, 18, 0, 10, $height-5, $color, './arial.ttf', $code);
    //输出图像
    header('Pragma:no-cache');
    header('Cache-Control:no-cache');
    header("content-type:image/png");
    imagepng($img);
    imagedestroy($img);
}

3. Verify verification code

When verifying the verification code, we usually get the verification code entered by the user and find the corresponding verification code in the session verification code value. If the verification code value stored in the session is consistent with the one entered by the user, the verification code verification is successful.

// 验证码验证
if(empty($verify)) {
    $this->error('验证码不能为空！');
}
if($verify != session('verify_code')){
    $this->error("验证码错误！");
}

4. Advantages of front-end and back-end separation verification code implementation

The front-end and front-end separation allows back-end developers to focus on data processing and logic business, and front-end developers can focus on users Development of experiences and interactions. At the same time, the separation of front-end and back-end improves the security of websites and web applications, and the use of verification codes can effectively prevent malicious automated access and attacks.

Summary:

thinkphp is an excellent PHP framework. It helps us develop web applications quickly and efficiently by providing flexible technical support. The process of implementing front-end and back-end separation verification codes involves front-end technologies, such as Canvas and JavaScript, and back-end technologies, such as Session and verification. By combining these technologies, we can ensure that our websites and web applications are more secure and the user experience is better.

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