Common security measures in PHP development

PHP is a programming language widely used in web development. Since PHP is widely used, security issues have become an inevitable problem in the PHP development process. In this article, we will explore the security measures commonly used during PHP development.

1. Input validation

Input validation is a crucial security measure during PHP development. Input validation refers to checking that user-supplied data conforms to specific rules. Before receiving data submitted by users, developers should perform data verification to ensure that the data provided by users is legal and safe.

For example, in a login form, developers should perform input validation on username and password. Username should contain only letters and numbers, and should be between 3 and 20 characters in length. Passwords should contain at least one number, one uppercase letter, and one lowercase letter, and should be between 8 and 20 characters in length. Input validation helps prevent malicious users from submitting malicious data.

2. Prevent SQL injection attacks

SQL injection attacks are a common form of network attack. You can gain illegal access to the database by entering SQL code in the input box. access permission. For example, an attacker can enter the following SQL code in a query form:

SELECT * FROM users WHERE username = 'admin' OR 1=1;

This query will return records for all users , not just the administrator's records. To prevent SQL injection attacks, developers should use parameterized queries and prepared statements. Using these methods, developers can pass input values ​​as parameters to the query statement, rather than embedding user-entered values ​​into the query statement.

The following is an example of using prepared statements to prevent SQL injection attacks:

$stmt = $pdo->prepare('SELECT * FROM users WHERE username = ?');

$stmt->execute([$username]);

3. Prevent cross-site scripting attacks

Cross-site scripting attack (XSS) is a A common method of network attack is for attackers to obtain users' sensitive information by inserting malicious scripts into web pages. For example, an attacker could insert the following Javascript code into a comment form: