How to Use PHP Forms to Prevent Security Hijacking

PHP form is one of the most commonly used elements in Internet applications. It appears in almost all login, registration, subscription, payment and submission operations. But at the same time, it is also one of the main entrances for network hacker attacks. Therefore, the prevention of PHP forms from security hijacking cannot be ignored. This article will introduce how to use PHP forms to prevent security hijacking and make some suggestions for the code.

1. Confirm submission method

Set the submission method on the PHP form to prevent data from being monitored, modified and stolen by unauthorized third parties. A good practice is to have a submission method for your form and validate it in your PHP code. Common submission methods include Post and Get. You can judge the form submission method by the REQUEST_METHOD in the $_SERVER array, as shown below:

if ($_SERVER['REQUEST_METHOD'] === 'POST' ) {
//Execute submission
}

This ensures that only data submitted through Post method can be processed.

2. Use verification code

Verification code is a simple and effective way to prevent attacks by robots and malicious programs. In PHP forms, verification codes can be used to prevent large-scale automated cracking attempts and maliciously submitted data. For example, when a user fills out a form, you can insert an image and ask the user to copy a letter or number from the image. The user's response is then compared to predefined answers in the library. If the response is correct, the user can proceed to submit the form.

3. Filtering user input

Filtering user input is an effective way to ensure data integrity. It can exclude any predefined characters, symbols, HTML tags and trim unnecessary spaces. This helps prevent malicious submissions from being used for XSS attacks, SQL injection, etc. In PHP forms, you can filter user input using the filter_var() function built into PHP. To learn more, see the official PHP documentation.

4. Use appropriate data types

In PHP forms, the use of various data types is also an important part of ensuring data integrity. When you need numbers or dates, make sure you use the correct data type in your PHP code, specifying the type internally using type conversion functions. Whether you need a string, an integer, or a date, it requires type conversion when storing and processing the data.

5. Use predefined form fields

You can use predefined PHP form fields, such as password, email, and url, etc., to ensure that the data is in the correct format and Further improve application security. These predefined fields include data validation and format checking to ensure that your application only accepts correctly formatted data.

6. Always validate data

Finally, even if you have protected your form with various security precautions, you should carefully validate the data in your PHP forms . In PHP, you can use various functions and normalization techniques to validate and process the received data, such as htmlspecialchars(), strip_tags(), htmlspecialchars_decode(), etc. These functions and techniques will help ensure that your applications are protected from malicious attacks and data breaches.

To sum up, for the security of PHP forms, we need to take a variety of means to prevent security hijacking. We can confirm the submission method, use captchas, filter user input, use appropriate data types, use predefined form fields, and always validate the data. These measures will help ensure the security of PHP forms you use in your application and provide a basis for the correctness of your code.

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