This blog post aims to demystify bearer authentication, explaining how it works and why it’s essential for securing your applications.
Bearer authentication (also called token authentication) is an HTTP authentication scheme that involves security tokens called bearer tokens.
The name “Bearer authentication” can be understood as “give access to the bearer of this token.” The bearer token is a cryptic string, usually generated by the server in response to a login request. The client must send this token in the Authorization header when making requests to protected resources:
Authorization: Bearer <token>The Bearer authentication scheme was originally created as part of OAuth 2.0 in RFC 6750, but is sometimes also used on its own. Similarly to Basic authentication, Bearer authentication should only be used over HTTPS (SSL).
How Does Bearer Authentication Work?
- Token Generation: When a user successfully authenticates (e.g., through username/password, OAuth, or other methods), the server issues a bearer token. This token is a cryptographically signed string containing information about the user or application, such as their ID, roles, and expiration time.
- Token Storage: The client securely stores the bearer token for subsequent requests to the API.
- Token Inclusion: For each protected resource request, the client includes the bearer token in the “Authorization” header.
- Token Validation: The server receives the request, extracts the token from the header, and validates it against its records. If the token is valid and the bearer has the required permissions, the request is authorized.
Common Use Cases
Bearer authentication is widely used in a variety of applications, including:
- Web applications: Protecting user data and preventing unauthorized access to sensitive resources.
- Mobile apps: Securing communication between the app and backend services.
- APIs: Controlling access to API endpoints and protecting sensitive data.
Best Practices
- Use strong encryption algorithms to protect the token.
- Set appropriate expiration times for tokens to mitigate risks.
- Implement robust token revocation mechanisms.
- Store tokens securely on the client side.