OIDC stands for OpenID. OpenID is basically an identity standard that works with the OAuth 2.0 authentication method. It was first published in 2014 and has been used by multiple identity providers globally since then.

What Is OpenID Connect (OIDC)?

The ODIC tries to access HTTPS-protected endpoints and verifies the user’s identity. The OpenID Foundation, which involves compromising platforms like Microsoft and Google, introduced an OIDC system that works on OAuth standards. OAuth only offers the services of authorization, while ODIC adds an extra layer of security to the whole authentication process.

Due to its extra protective authentication features, you can now use it for SSO, which allows access to multiple applications or websites with one social login. Single Sign-On is one of the easiest ways to log in to different sites and accounts without using different usernames and passwords. Here, OIDC comes as the next generation user management technology that helps manage and authenticate users’ identities.

How Does OpenID Connect Work?

ID Tokens

Traditional OAuth works in a flow in which users give their login username and password to the authentication provider. Upon this, users get an authorization request to allow the this-part application to use their credentials to the authentication provider. Here, OAuth sends an access token to the apps to validate the user’s identity. However, it does not provide any information.

OIDC works similarly to authenticate the identity of the user and give an ID Token. This ID Token contains identifiable data about the user, such as their email and name. The third-party app can verify the users with the help of this ID Token.

Standardized Scopes

OAuth basically uses scopes and tokens:

The token is basically a permit for the user to do things on the application. For instance, a token is like a ticket that allows people to enter a palace. On the other hand, scope allows users to do specific tasks. For instance, it’s like a ticket with instructions that allow people to enter a specific area at a specific time.

The traditional OAuth protocol did not have a scope system, and applications decided on their scopes themselves.

OpenID Connect Flows

OpenID Connect has stopped using the grant. On the other hand, OAuth thinks it is an insecure move. OIDC uses PKCE, which means it works on Proof Key in the Exchange of Code to prevent identity code injection and CSRF breaches.

OIDC Implicit Flow

This flow is basically used for web-based applications and non-sensitive information. It enables authorization at the user endpoint to directly ask for identity tokens or access tokens of OAuth.

The OIDC implicit flow is not a very secure method because browser can see its identity and access tokens. This gives a space for the attacks to happen. Therefore, it is best that you only use the OIDC implicit flow method for non-sensitive data that do not contain any personal information.

OIDC Authentication Flow

OIDC Authentication flow works for browser-based applications that need to communicate with the authentication provider on the backend. This flow is divided into three parts, in which OAuth returns the tokens to third-party web-based applications through backend communication. It does not send users’ information directly. Instead, it provides a one-time number code. This code is then exchanged with the OAuth token to give the web the ID of the client.

This is considered one of the secure flows of OIDC because tokens are not visible to the browser which makes the whole authentication process safer.

OIDC Authorization Code Flow

Server-side applications are the main use case for this flow. Apps can request permission codes from the user identification endpoint for it to function. These authorization codes can then be swapped for OAuth access or identity tokens when required.

Refresh tokens enable activities on the user’s behalf, regardless of whether the access and identity tokens are hidden from the browser. Because they can be trusted to keep the secrets secure, confidential clients should be the only ones with access to the authorization code flow. This flow requires meticulous planning and ongoing observation.

OIDC Hybrid Flow

This flow can be used by clients who need to process the identification code before they can exchange it for access tokens or insensitive data. Authorization endpoints send back tokens and authorization codes. Client apps may employ PKCE to stop illegal authorization code injections, and endpoints can conduct nonce verification beforehand.

Since this option exposes access tokens to the web browser, it is inappropriate for sensitive data. This flow works the same as the authorization code and allows activities to be carried out on users’ behalf when they are not online. Please keep it to private clientele only.

What Is an OpenID Connect Provider?

A verified OpenID Provider library that offers a safe authentication method for API security and Node.js applications is known as an OIDC Provider. It does not allow the installation and change of individual components. Instead, it offers an authentication framework. It might not work well in situations where you need grant types. All five profiles of OpenID are library-certified.

Currently, Microsoft, Google, Yahoo, Amazon, Okta, and PayPal are the leading public OpenID Connect providers. Except for Amazon and Okta, the majority of these choices offer JSON-formatted discovery information.

Benefits of OIDC for Developers

Developers who immensely support mobile apps, web-based apps, and APIs can greatly benefit from this safest OIDC authentication mode. Some of its most common advantages include:

1.    No More Managing Passwords

Instead of using credentials to log in to a new application, using tokens to complete the authentication and authorization procedures relieves developers of the burden of creating, maintaining, and handling passwords. This is one of the common sources of data breaches.

2.    Higher Security

The use of tokens makes the OIDC a secure authentication standard. Users may sign in to several programs without creating new accounts and passwords. As users do not have to share their credentials to log in, the whole process is less risky and more secure.

3.    Ease of Implementation

It is one of the safest open protocols to share information between authentication services and third-party websites.

OIDC Best Practices for Relying Parties

RP stands for Relying Party, a company that uses OIDC to verify users’ identity on third-party applications. Following are some practices that RPs must use:

1. Apply XSRF security to all web links that may be used, updated, or changed by the users’ account state. Make sure to protect users from CSRF and XSS breaches.
2. Try to use the currently available OpenID Connect Library. You don’t have to integrate the OIDC from zero. Instead, you can use verified openlibrary sources like OpenID.net for it.
3. Make sure that the identity sessions do not last for a longer period than the standard authentication period. You can also check the status of the user that is always logged in the Service Provider by using the checkid_immediate() provider protocol.
4. Create a discovery doc that lists all of your OpenID user’s endpoints and makes sure it can be found to integrate RP Discovery. The OpenID provider uses a discovery document to verify the authenticity of identification requests.
5. You can use PAPE extensions to contact the OID provider to offer protection policies for users’ authentication.

OIDC vs. OAuth2

The main function of OAuth 2.0 is to provide an authorization system that enables third-party apps to access user information on the Internet. Access tokens from OAuth2 enable these apps to access the user’s resources on a user’s behalf. However, the information does not include any personal details of the user.

OIDC, on the other hand, is based on OAuth2 with an additional authentication layer. It allows the client to confirm the end-user’s identity using the authentication that an Authorization Server has carried out. Open ID gives ID Tokens, which are then used to verify user authentication and include user data. Compared to OAuth2 alone, this combination makes OIDC more appropriate for SSO applications.