How do you configure basic authentication in Spring Security?

Table of Contents

• Introduction
• Steps to Configure Basic Authentication in Spring Security
  • 1. Add Spring Security Dependency
    • Maven:
    • Gradle:
  • 2. Create a Security Configuration Class
    • Example Configuration:
  • Explanation:
  • 3. Define User Credentials
    • In-Memory Authentication (for testing purposes)
  • Explanation:
  • 4. Testing Basic Authentication
• Customizing Basic Authentication
  • Securing Specific Endpoints
  • Adding Custom Authentication Filters
• Conclusion

Introduction

Basic Authentication is one of the simplest forms of authentication used to verify users by sending their credentials (username and password) with each HTTP request. It’s often used in APIs or web applications that don't require complex authentication mechanisms.

In Spring Security, basic authentication is easy to configure and ensures that your application can securely handle user requests. This guide will explain how to configure basic authentication in a Spring Boot application using Spring Security.

Steps to Configure Basic Authentication in Spring Security

1. Add Spring Security Dependency

If you're working with a Spring Boot project, you need to add the spring-boot-starter-security dependency in your pom.xml or build.gradle file to integrate Spring Security.

Maven:

Gradle:

Spring Boot will automatically configure some default security settings, but we can customize it for basic authentication.

2. Create a Security Configuration Class

The next step is to create a custom security configuration class where you will define your basic authentication settings. Spring Security uses the HttpSecurity object to configure HTTP security settings.

Here's an example of a basic configuration that enables HTTP Basic Authentication:

Example Configuration:

Explanation:

• **authorizeRequests()**: Defines access rules for different URLs. Here, /public/** is allowed for unauthenticated users, but any other request requires authentication.
• **httpBasic()**: Enables HTTP Basic Authentication, where the user must send their username and password with each request.
• **csrf().disable()**: This is often disabled for APIs to simplify the configuration (you can re-enable it depending on your needs).

3. Define User Credentials

You need to specify user credentials for authentication. You can either configure an in-memory user store, a JDBC-based store, or a custom user service.

In-Memory Authentication (for testing purposes)

For simplicity, you can define an in-memory user store like this:

Explanation:

• **inMemoryAuthentication()**: Configures an in-memory user store with two users: "user" and "admin" with different passwords and roles.
• **passwordEncoder()**: A BCryptPasswordEncoder is used to securely encode passwords (it’s a best practice to never store plain-text passwords).
• **httpBasic()**: Enables Basic Authentication, ensuring users send their credentials with each request.

4. Testing Basic Authentication

Once your configuration is in place, you can test basic authentication by accessing a protected endpoint, such as http://localhost:8080/.

Use the following curl command to make a request with basic authentication:

This will prompt Spring Security to authenticate the request using the credentials user:password. If successful, the resource will be returned.

Customizing Basic Authentication

Securing Specific Endpoints

You can secure specific endpoints using .antMatchers() in the configuration.

Adding Custom Authentication Filters

You can also customize the authentication process by creating a custom filter, such as for JWT-based authentication, while still keeping the basic authentication functionality.

Conclusion

Configuring Basic Authentication in Spring Security is straightforward and provides a quick way to secure your application, especially for APIs. You can define user roles, control access to specific endpoints, and ensure that authentication is performed with each request. Although basic authentication is simple, it's important to remember that it sends credentials with each request in plain text (unless over HTTPS), so it should be used carefully, especially in production environments. For more complex use cases, consider integrating OAuth2, JWT, or LDAP authentication mechanisms.