如何在Linux中使用PAM添加密码 (linux pam添加密码)

How to add password authentication with PAM on Linux

As the backbone of modern computing systems, security has become one of the most crucial aspects of mntning and managing Linux servers. Ensuring that users authenticate themselves before accessing sensitive data or systems is an essential part of this security process. One way to achieve this is by using Pluggable Authentication Modules (PAM), a powerful authentication framework that allows you to add authentication to various applications and services running on your Linux system. In this article, we will explore how to use PAM to add password authentication to a Linux server.

Understanding PAM

Before we dive into the process of adding password authentication with PAM, it is crucial to understand what PAM is and how it works. PAM is a modular authentication framework that separates the authentication process for different applications or services running on your system. PAM works by loading the appropriate authentication module(s) that correspond with a specific service request. These modules handle the authentication process and report back to the PAM framework on whether the authentication was successful or not. This approach makes it easy to configure different authentication methods depending on the service request or application.

Step 1: Installing the necessary PAM module

The first step in adding password authentication with PAM is to install the necessary PAM module. Depending on your Linux distribution, the PAM module required may differ. However, most Linux distributions include a PAM module for password authentication already installed by default. To install the module manually, you can use your distribution’s package manager. For example, if you are using Ubuntu or Debian, you can install the necessary module by running the following command:

sudo apt-get install libpam-modules

Step 2: Configuring PAM

Now that we have installed the necessary PAM module, we need to configure it to add password authentication. PAM configuration files are typically located in the /etc/pam.d/ directory. Each service or application has its own configuration file, and each file contns the PAM rules that specify the authentication mechani for that application or service.

In this example, we will add password authentication for SSH. The SSH PAM configuration file is located in /etc/pam.d/sshd. To add password authentication, we need to modify this file.

First, create a backup of the file using the following command:

sudo cp /etc/pam.d/sshd /etc/pam.d/sshd.bak

Next, open the SSH PAM configuration file using a text editor such as nano:

sudo nano /etc/pam.d/sshd

In the SSH PAM configuration file, you will see a list of PAM rules. To add password authentication, we need to add a new rule that specifies the PAM module for password authentication. This can be done by adding the following line at the beginning of the file:

auth required pam_unix.so

This PAM rule specifies that the authentication method used will be the traditional Unix password authentication method. Once you have added this line, save and close the file.

Step 3: Testing password authentication

Now that we have configured PAM for password authentication, we need to test it to ensure it is working as intended. To do this, you can try to SSH into your Linux server using a user account that has a password configured.

Once you try to SSH into the server, you should be prompted for a password. Once you enter the correct password, you should be granted access to the Linux server. If the password authentication does not work, review the SSH PAM configuration file and ensure you have followed the steps correctly.

Conclusion

By leveraging PAM, adding password authentication to your Linux server becomes an easy and effective process. PAM not only allows you to add password authentication, but it also enables you to configure various authentication methods to meet the specific needs of your applications and services. When coupled with other security measures, such as firewall configuration and a comprehensive backup strategy, PAM can help you build a robust and secure Linux environment for your organization.