dart_firebase_admin createCustomToken generates invalid Token

When i send the token back to the client and trie the LoginWithToken method I get: error: [firebase_auth/invalid-custom-token] The custom token format is incorrect. Please check the documentation.

If i paste the token into jwt.io i get the following warning (although I can see the correct payload of the token. Warning: Looks like your JWT signature is not encoded correctly using base64url (https://tools.ietf.org/html/rfc4648#section-5). Note that padding ("=") must be omitted as per https://tools.ietf.org/html/rfc7515#section-2

I did double check that the projects match and got it to work with the python admin sdk.

Any Ideas?

Thanks Mark

Dec 17 '23 13:12 markbreuss

When i send the token back to the client and trie the LoginWithToken method I get:

What does that mean exactly? Maybe some code samples would help here

Dec 17 '23 13:12 rrousselGit

Of course so my workflow is:

HTTP Request to Dart Backend (DartFrog) to get the token
On the Server Endpoint I have the following code to generate the token auth.createCustomToken(uid, developerClaims: {'role': 'm1_admin'});
On the client I use the token I genereated in step 2 to sign in with the flutter client sdk: FirebaseAuth.instance.signInWithCustomToken(token);

This is where I get the error: error: [firebase_auth/invalid-custom-token] The custom token format is incorrect. Please check the documentation.

Dec 17 '23 14:12 markbreuss

I'm also having this issue, I'm just using the createCustomToken without any claims and I can't use the token with the signInWithCustomToken endpoint. Same error about the formatting