Signing in users with OIDC
This document shows you how to use Identity Platform to sign in users with an OpenID Connect (OIDC) provider.
Before you begin
- Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
-
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Google Cloud project.
-
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Google Cloud project.
- Enable Identity Platform, and add the client SDK to your app. See the Quickstart to learn how.
Configuring the provider
Go to the Identity Providers page in the Google Cloud console.
Go to the Identity Providers pageClick Add a Provider, and select OpenID Connect from the list.
Authorization Code Flow
Enter the following details to enable the Authorization Code Flow:
Select Code Flow under Choose grant type section.
The Name of the provider. This can be the same as the provider ID, or a custom name. If you enter a custom name, click Edit next to Provider ID to specify the ID (which must begin with
oidc.
).The provider's Client ID.
The provider's Issuer. This should look something like
https://example.com
. Identity Platform uses this URL to locate the OIDC discovery document (typically found at/.well-known/openid-configuration
), which specifies the provider's OAuth endpoints and public keys.The provider's Client Secret.
Add your app to the list of Authorized Domains. For example, if your app's sign-in URL is
https://example.com/login
, addexample.com
.Configure the Identity Platform callback URL as a redirect URL with your OIDC provider. The URL should look similar to
https://[PROJECT-ID].firebaseapp.com/__/auth/handler
.Click Save.
Implicit Flow
Enter the following details to enable the Implicit Flow:
Select Implicit Flow under Choose grant type section.
The Name of the provider. This can be the same as the provider ID, or a custom name. If you enter a custom name, click Edit next to Provider ID to specify the ID (which must begin with
oidc.
).The provider's Client ID.
The provider's Issuer. This should look something like
https://example.com.
Identity Platform uses this URL to locate the OIDC discovery document (typically found at/.well-known/openid-configuration
), which specifies the provider's OAuth endpoints and public keys.
Add your app to the list of Authorized Domains. For example, if your app's sign-in URL is
https://example.com/login
, addexample.com
.Configure the Identity Platform callback URL as a redirect URL with your OIDC provider. The URL should look similar to
https://[PROJECT-ID].firebaseapp.com/__/auth/handler
.Click Save.
Signing in users
There are two ways to sign in users with OIDC:
Using OAuth flow. This way completes the OAuth handshake for you. Based on the Authorization Code Flow/Implicit Flow selection at the configuring provider step, GCIP server chooses the desired flow to communicate with the Identity Provider.
Using the OIDC provider's ID token. This way assumes you already have an OIDC token available.
Signing in users with OAuth
To sign in using OAuth:
Create an
OAuthProvider
instance with the provider ID you configured in the previous section. The provider ID must start withoidc.
.Web version 9
import { OAuthProvider } from "firebase/auth"; const provider = new OAuthProvider("oidc.myProvider");
Web version 8
const provider = new firebase.auth.OAuthProvider('oidc.myProvider');
Start the sign in flow. You can choose to either use a popup or a redirect.
Popup
Web version 9
import { getAuth, signInWithPopup, OAuthProvider } from "firebase/auth"; const auth = getAuth(); signInWithPopup(auth, provider) .then((result) => { // User is signed in. const credential = OAuthProvider.credentialFromResult(result); // This gives you an access token for the OIDC provider. You can use it to directly interact with that provider }).catch((error) => { // Handle Errors here. const errorCode = error.code; const errorMessage = error.message; // The email of the user's account used. const email = error.customData.email; // The AuthCredential type that was used. const credential = OAuthProvider.credentialFromError(error); // Handle / display error. // ... });
Web version 8
firebase.auth().signInWithPopup(provider) .then((result) => { // User is signed in. // result.credential is a firebase.auth().OAuthCredential object. // result.credential.providerId is equal to 'oidc.myProvider'. // result.credential.idToken is the OIDC provider's ID token. }) .catch((error) => { // Handle error. });
Redirect
To redirect to a sign-in page, call
signInWithRedirect()
:Web version 9
import { getAuth, signInWithRedirect } from "firebase/auth"; const auth = getAuth(); signInWithRedirect(auth, provider);
Web version 8
firebase.auth().signInWithRedirect(provider).catch((error) => { // Handle error. });
Then, call
getRedirectResult()
to get the results when the user returns to your app:Web version 9
import { getAuth, getRedirectResult, OAuthProvider } from "firebase/auth"; const auth = getAuth(); getRedirectResult(auth) .then((result) => { // User is signed in. const credential = OAuthProvider.credentialFromResult(result); // This gives you an access token for the OIDC provider. You can use it to directly interact with that provider }) .catch((error) => { // Handle Errors here. const errorCode = error.code; const errorMessage = error.message; // The email of the user's account used. const email = error.customData.email; // The AuthCredential type that was used. const credential = OAuthProvider.credentialFromError(error); // Handle / display error. // ... });
Web version 8
// On return. firebase.auth().getRedirectResult() .then((result) => { // User is signed in. // result.credential is a firebase.auth().OAuthCredential object. // result.credential.providerId is equal to 'oidc.myProvider'. // result.credential.idToken is the OIDC provider's ID token. }) .catch((error) => { // Handle / display error. // ... });
At the conclusion of either flow, you can get the OIDC ID token using the
result.credential.idToken
field.
Signing in users directly
To sign a user in with an OIDC ID token directly, do the following:
Initialize an
OAuthProvider
instance with the provider ID you configured in the previous section. The provider ID must start withoidc.
. Then, create anOAuthCredential
, and callsignInWithCredential()
to sign the user in.Web version 9
import { getAuth, OAuthProvider, signInWithCredential } from "firebase/auth"; const auth = getAuth(); const credential = provider.credential({ idToken: oidcIdToken, }); signInWithCredential(auth, credential) .then((result) => { // User is signed in. const newCredential = OAuthProvider.credentialFromResult(result); // This gives you a new access token for the OIDC provider. You can use it to directly interact with that provider. }) .catch((error) => { // Handle Errors here. const errorCode = error.code; const errorMessage = error.message; // The email of the user's account used. const email = error.customData.email; // The AuthCredential type that was used. const credential = OAuthProvider.credentialFromError(error); // Handle / display error. // ... });
Web version 8
const credential = provider.credential(oidcIdToken, null); firebase.auth().signInWithCredential(credential) .then((result) => { // User is signed in. // User now has a odic.myProvider UserInfo in providerData. }) .catch((error) => { // Handle / display error. // ... });
Linking user accounts
If a user has already signed in to your app using a different method (such as email/password), you can link their existing account to the OIDC provider using linkWithPopup()
or linkWithRedirect()
:
For example we can link with a Google account:
Web version 9
import { getAuth, linkWithPopup, GoogleAuthProvider } from "firebase/auth"; const provider = new GoogleAuthProvider(); const auth = getAuth(); linkWithPopup(auth.currentUser, provider).then((result) => { // Accounts successfully linked. const credential = GoogleAuthProvider.credentialFromResult(result); const user = result.user; // ... }).catch((error) => { // Handle Errors here. // ... });
Web version 8
auth.currentUser.linkWithPopup(provider).then((result) => { // Accounts successfully linked. var credential = result.credential; var user = result.user; // ... }).catch((error) => { // Handle Errors here. // ... });
What's next
- Signing in users with SAML
- Showing a custom domain during sign in
- Managing OIDC and SAML providers programmatically