Network security technology in PHP

With the continuous development of computer technology, the Internet has become an indispensable part of people's lives and work. The application scope of the network is getting wider and wider, making network security issues a hot topic at present. In this context, in order to solve network security problems, network security technology in PHP has become an important field. This article will introduce some common network security techniques in PHP.

1. Code injection attack

In PHP, the most common means of network attack is code injection attack. This attack method mainly involves entering malicious code, causing the server to execute the malicious code, leading to serious consequences such as system paralysis or data leakage by the attacker. In order to prevent code injection attacks, PHP's network security technology mainly uses the following methods:

1. Filter input data. In PHP, some built-in functions can filter input that does not meet the requirements. For example, the htmlspecialchars function will encode input containing special characters to protect the security of the system.

2. For sensitive operations, identity verification is required. Only users who have passed authentication can perform sensitive operations, such as changing passwords, deleting data, etc.

3. Strictly restrict permissions. Specific permissions should be set up for each user to avoid illegal operations on the server.

2. File processing

In PHP, file processing is a relatively important operation. Some unsafe situations may occur during file upload, download, deletion and other operations. To ensure the security of files, the network security technology in PHP mainly adopts the following methods:

1. File permission control. To control file permissions on uploaded files to prevent unauthorized users from accessing files, you can use the chmod function to control file permissions.

2. Verify the uploaded file. Limit uploaded file types to avoid illegal file type uploads. For example, only jpg, png, and gif format images are allowed to be uploaded.

3. Check the file name. To avoid illegal file names, such as not allowing file names to contain special characters, you can use PHP's regular expression function to solve the problem.

3. Password security

Password is the sensitive information of the user account. If the password is leaked, it will bring unnecessary trouble to the user. The network security technology in PHP mainly uses the following methods to ensure the security of passwords:

1. Encrypt the password. When storing passwords, use an encrypted method, such as md5, sha1, etc., so that even if the password is leaked, the original password cannot be easily obtained.

2. Perform security check on login operation. Limit the number of logins, avoid violent guessing of passwords, and use verification codes and other methods to protect login operations.

3. Do not transmit passwords in clear text. When transmitting passwords, do not use plain text transmission, and use encryption methods such as https to ensure the security of the transmission.

4. Prevent SQL Injection

In PHP, SQL injection is a very common attack method. It is a method for hackers to obtain database information through malicious SQL statements. Network security technology in PHP mainly uses the following methods to avoid SQL injection attacks:

1. Use prepared statements. Using PHP's built-in preprocessing functions such as PDO and mysqli, you can precompile SQL statements to prevent user-entered data from being directly spliced ​​into SQL statements, causing the database to be attacked.

2. Filter user input. When obtaining user input data, filter it through some built-in functions to escape the data entered by the user to avoid the impact of special characters entered by the user on the database.

The above are some common network security technologies in PHP. These technologies can effectively protect the security of the system and avoid the adverse effects of network security issues on the system.

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