OpenID Connect (OIDC) is an extension of the OAuth 2.0 protocol and is used for secure and efficient authentication of users and technical services. OIDC stands for OpenID Connect and is an extension of the OpenID protocol. It was developed to overcome the limitations of the original OpenID standard and provides advanced security mechanisms and user information transfer.
Authorization and authentication of digital identities
OpenID Connect builds on the OAuth 2.0 protocol developed for authorization and extends it to enable authentication as well.
The terms “authentication” and “authorization” are often confused with each other or used interchangeably, although they represent different concepts in information security. Here, therefore, is an easy-to-understand explanation of the two IT security concepts:
Authentication
Authentication is the process of verifying the identity of a person, system, or entity. Simply put, authentication ensures that you are who you say you are. This is usually done by entering a username and password, but it can also be done through other mechanisms such as biometrics, smart cards, or two-factor authentication (2FA).
In the context of OpenID and OpenID Connect, authentication is the step where the user confirms their identity to an Identity Provider (IdP).
A successful authentication process usually results in the issuance of a token representing this confirmed identity.
Example of a valid token in the OIDC authentication process
Here you can see a JSON web token as an illustrative example of a token with a cipher suite considered secure such as ES256 (Elliptic Curve Digital Signature Algorithm) for the algorithm:
JWT Header:
{
“alg”: “ES256”,
“kid”: “e9bc097a-ce51-4036-9562-d2ade882db0d”
}
JWT Payload:
{
“iss”: “https://identity-provider.com”,
“sub”: “1234567890abcdef”,
“aud”: “your-client-id”,
“exp”: 1621843200,
“iat”: 1621842600,
“nonce”: “random-nonce-string”,
“auth_time”: 1621842600
}
This example uses the ES256 algorithm, which uses elliptic curve cryptography (ECC) and is still considered secure. The kid (Key ID) would be an identifier for the public key used to verify the token.
After the header and payload are generated, they would be encoded and signed with the identity provider’s private key to produce the full JWT. It would be a combination of these encoded and signed values, separated by dots ..
Authorization
After authentication comes authorization. It determines which resources or actions the authenticated user or system may access or perform. These can be files, databases, APIs and other protected resources. Authorization therefore ensures that you are only allowed to do what you are authorized to do.
In the context of OpenID and OAuth 2.0, authorization is often the next step after authentication. Here, an access token is issued to the client (the application that authenticated the user). This token defines which resources the client is allowed to retrieve or manipulate on behalf of the user.
OIDC explained compactly:
- Authentication: Confirms that you are who you say you are.
- Authorization: Determines what you are allowed to do after your identity has been confirmed.
Both concepts are critical in the context of information security and when dealing with identity management in digital systems, and they often work hand in hand to provide a comprehensive security mechanism.
OIDC is thus much more flexible and secure than the original OpenID protocol. It also allows the transfer of more user information and has advanced security features. OIDC is now the common Auth standard protocol and has replaced OpenID in many applications.
- Authentication: Verification of the identity of a user or a service.
- OAuth 2.0: An open standard protocol for secure API authorization.
- Identitätsprovider (IdP): A service that manages user identities and provides authentication services.
- Token: A short piece of data that serves as an identifier or access key.
Background and development
The OpenID Foundation launched OIDC as a modernized version of the original OpenID standard to better meet the needs of today’s complex digital ecosystems. It offers enhanced capabilities for transferring user information and improved security features.
Technical basics
Authentication flow
OpenID Connect uses several authentication flows based on the OAuth 2.0 framework. The most commonly used rivers are:
- Authorization Code Flow: Suitable for server-to-server authentication.
- Implicit Flow: Suitable for browser-based applications.
- Hybrid Flow: A combination of the two rivers mentioned above.
Tokens
OpenID Connect uses several types of tokens:
- ID Token: Contains the user’s identity information.
- Access Token: Used to access protected resources.
- Refresh Token: Used to obtain new Access Tokens without having to authenticate the user again.
OpenID Connect vs. OpenID
While OpenID was primarily designed for authentication, OpenID Connect extends these capabilities with the ability to securely and efficiently transfer additional user information.
Significance and relevance of OpenID Connect in software development
OpenID Connect (OIDC) has important meaning and relevance in software development because it provides a standardized method for authenticating users. It builds on the OAuth 2.0 protocol and extends it with the ability to exchange both identity information and authentication information between the identity provider and the service provider. Here are some reasons why OpenID Connect is so relevant in software development:
Simplified authentication
The use of OIDC facilitates the implementation of secure authentication methods. Developers don’t have to build their own authentication systems from scratch, which saves time and reduces potential points of failure.
Standardization
OIDC provides an industry standard that is supported by many large companies and organizations. This standardization greatly facilitates the integration of various services and applications.
Improved security
Compared to simple authentication methods such as username and password, OIDC offers advanced security features such as multi-factor authentication, short-lived tokens, and automatic token renewal.
Federated identities
Through OIDC, users can share their identity across different services without having to create new credentials each time. This is not only user-friendly, but also enables a secure and consistent user experience across different services.
Use case diversity
OIDC can be used in a variety of use cases, from web and mobile applications to API security and microservices architectures.
Flexibility and expandability
By using JSON Web Tokens (JWT) for identity information, OIDC provides a flexible and extensible structure that can be easily customized to meet specific requirements.
Data efficiency and speed
OIDC is designed to exchange minimal amounts of data between the client and the server, resulting in faster processing and lower network latencies.
Overall, OpenID Connect’s standardization, security features and flexibility make it an attractive option for authentication and identity management in modern software development projects.
OpenID Foundation and Support
The OpenID Foundation offers a wealth of information such as specification details, as well as training, partnerships and a certification program. With these offerings, the Foundation promotes the dissemination and implementation of OIDC and, in return, guarantees its interoperability and security.
Conclusion
OpenID Connect is an advanced protocol for secure and efficient authentication in the modern digital world. By extending the OAuth 2.0 framework, it provides improved functionality and addresses the limitations of the original OpenID standard.
