Custom Auth Solutions

Custom authentication solutions are essential for securing front-end applications, allowing developers to tailor the authentication process to meet specific needs.

Authentication: The process of verifying a user's identity.

Authorization: The process of granting access to resources based on user identity.

JWT (JSON Web Tokens): A compact, URL-safe means of representing claims to be transferred between two parties.

OAuth: An open standard for access delegation commonly used as a way to grant websites or applications limited access to user information.

3.1 JWT Authentication Flow

The JWT flow consists of the following steps:

1. User logs in with credentials.
2. Server verifies credentials and issues a JWT.
3. User stores the JWT in local storage or a cookie.
4. On subsequent requests, the user sends the JWT in the Authorization header.
5. Server verifies the JWT and grants access to protected resources.

        // Example of JWT generation in Node.js
        const jwt = require('jsonwebtoken');

        const user = { id: 1, username: 'example' };
        const token = jwt.sign(user, 'secret_key', { expiresIn: '1h' });
        console.log(token);
            

3.2 OAuth 2.0 Flow

OAuth allows third-party services to exchange user credentials securely:

1. User clicks on "Login with Provider".
2. User is redirected to the OAuth provider (e.g., Google).
3. User grants permission for the application to access their data.
4. Provider redirects back with an authorization code.
5. Application exchanges the code for an access token.
6. User accesses resources using the access token.

        // Example of exchanging authorization code for access token
        const axios = require('axios');

        const tokenResponse = await axios.post('https://provider.com/oauth/token', {
            code: 'authorization_code',
            redirect_uri: 'your_redirect_uri',
            client_id: 'your_client_id',
            client_secret: 'your_client_secret',
        });
        console.log(tokenResponse.data.access_token);
            

3.3 Flowchart Representation

        graph TD;
            A[User Login] --> B[Server Verifies Credentials];
            B --> C{Valid?};
            C -->|Yes| D[Generate JWT];
            C -->|No| E[Return Error];
            D --> F[Send JWT to User];
            F --> G[User Sends JWT on Requests];
            G --> H[Server Validates JWT];
            H --> I{Authorized?};
            I -->|Yes| J[Access Resource];
            I -->|No| K[Return Unauthorized];
            

Follow these best practices when implementing custom authentication:

• Use HTTPS to encrypt data in transit.
• Store sensitive tokens securely (e.g., HttpOnly cookies).
• Implement token expiration and refresh mechanisms.
• Limit token scope and permissions.
• Regularly rotate secrets and keys.