Implementing secure user authentication and authorization in Go typically involves the following steps:
Store User Credentials: Use a secure hashing algorithm like bcrypt or scrypt to hash and store user passwords. Never store passwords in plaintext.
User Registration: Create an endpoint to register new users. Validate and sanitize user input, and then securely hash and store the user's password in your database.
User Login: Create an endpoint to handle user login requests. Validate user input, retrieve the stored password hash from the database, and compare it with the entered password using the bcrypt.CompareHashAndPassword function. If the password matches, generate a secure session token (JWT - JSON Web Token) and return it to the user.
Protect Routes: Implement middleware to protect routes that require authentication. Use the session token from the user's request to authenticate and authorize the user. You can use a library like jwt-go to parse and validate the token.
Authorization: Implement authorization checks to control access to resources based on user roles or permissions. Store user roles or permissions in your database and verify them during the authorization process.
Logout: Create an endpoint to handle user logout requests. Invalidate the session token and update the session state accordingly.
Secure Session Handling: Store session tokens securely (e.g., use HttpOnly and secure cookies) and enforce proper session management to prevent session hijacking or session fixation attacks.
Password Reset: Implement a password reset mechanism that allows users to securely reset their forgotten passwords. Generate a secure token and send it to the user's registered email address. Verify the received token and securely update the user's password in the database.
Remember, building a secure authentication and authorization system requires careful consideration of potential vulnerabilities, such as cross-site scripting (XSS), cross-site request forgery (CSRF), and session related attacks. Regularly updating and patching your dependencies is also essential for maintaining security.