How do I get the access token from a code I already have?

[cinjon]

I used ReactGoogleLogin (https://github.com/anthonyjgrove/react-google-login) to get the offline code. This works fine and is associated with my clientId. I then want to have the server complete the process with this API.

Doing the following does not work and yields an error oauthlib.oauth2.rfc6749.errors.InvalidGrantError: (invalid_grant) code_verifier or verifier is not needed.. How do I fix this?

def fetch_token(code):
  flow = Flow.from_client_secrets_file(</path/to/credentials.json>, [list of scopes], 
    redirect_uri='urn:ietf:wg:oauth:2.0:oob')
  flow.fetch_token(code)

Note that I tried this w/ and w/o the redirect_uri. I also tried it with the redirect_uri for my website. All gave the same error.

[cinjon]

I changed this to use a site-specific redirect uri and now I'm getting:

oauthlib.oauth2.rfc6749.errors.CustomOAuth2Error: (redirect_uri_mismatch) Bad Request

This seems pretty common but none of the solutions I see are working for me.

[busunkim96]

Hiya @cinjon

I think you're running into a bug introduced in v0.4.0. Please use 0.3.0 until the fix is released in 0.4.1

[cinjon]

I tried downgrading and am still getting the same error:

oauthlib.oauth2.rfc6749.errors.CustomOAuth2Error: (redirect_uri_mismatch) Bad Request

[cinjon]

Is there a way to get more visibility into what is the error? All I'm seeing is oauthlib.oauth2.rfc6749.errors.CustomOAuth2Error: (redirect_uri_mismatch) Bad Request but the redirect_uri is the same on both the client and the server.

(@cc @busunkim96 )

[busunkim96]

Hmm, can verify that the desired redirect_uri is in the credentials.json file? It should be listed under the redirect_uris field.

[cinjon]

So that was an issue, and I've now updated it - and I still get the same error. Fwiw, this is all happening in local development.

My current credentials.json looks like:
{"web":{"client_id":"<blah>.apps.googleusercontent.com","project_id":"<blah>","auth_uri":"https://accounts.google.com/o/oauth2/auth","token_uri":"https://oauth2.googleapis.com/token","auth_provider_x509_cert_url":"https://www.googleapis.com/oauth2/v1/certs","client_secret":"<blah>","redirect_uris":["https://localhost:3000/google_oauth_redirect","http://localhost:3000/google_oauth_redirect","http://localhost:5000/google_oauth_redirect","https://localhost:5000/google_oauth_redirect"],"javascript_origins":["https://localhost:3000","http://localhost:3000","https://localhost:5000","http://localhost:5000"]}}

As you can see, I have inserted all the things I could think of to try and get it to not be a mismatch. I've also tried the redirect_uri combinations in my local JS as well.

Do you have more suggestions? That last one was really useful. Thanks!

[busunkim96]

@cinjon Did you edit the file manually? If so, you should go to the API console and edit your existing OAuth client ID. After that you can re-download the credentials.

[cinjon]

I didn't. I downloaded it from the console.

[busunkim96]

It looks like the library you linked is using gapi under the hood. You might want to take a look at that documentation as well.

https://developers.google.com/identity/sign-in/web/reference#gapiauth2clientconfig

There are some more general suggestions in this stackoverflow post.

[busunkim96]

When you do figure out the solution, would you mind posting back here? It will help who stumbles on this issue in the future. 😃

[Andras1000]

This happened to me after trying to use the OAuth2 authorization code more then once.

The solution for me was to get a fresh authorization code.

[jahangirkabir]

I am also getting the same error with version 0.4.2

[busunkim96]

Revisiting this, I think @Andras1000 is correct.

To get a new access token you need to use the refresh token.

Documentation:

• https://developers.google.com/identity/protocols/oauth2
• https://developers.google.com/identity/protocols/oauth2/web-server#offline

[bhavaygg]

@busunkim96 How do i get the refresh token tho? I have got the authorization code from the front end and want to store the refresh token in my django backend.

[busunkim96]

@Chokerino The authorization code should be exchanged for a refresh token. https://developers.google.com/identity/protocols/oauth2/web-server#exchange-authorization-code