exchangeCodeForToken method

Future<({String accessToken, String idToken})> exchangeCodeForToken(Session session, { required String code, required String codeVerifier, required String redirectUri, })

Exchanges a Google authorization code for access and ID tokens.

Used by the web OAuth2 PKCE flow initiated by GoogleWebSignInService. The codeVerifier is the PKCE verifier, and redirectUri must exactly match the URI used in the original authorization request.

Throws GoogleIdTokenVerificationException if the token exchange fails or if the response is missing the id_token.

Implementation

Future<({String accessToken, String idToken})> exchangeCodeForToken(
  final Session session, {
  required final String code,
  required final String codeVerifier,
  required final String redirectUri,
}) async {
  try {
    final tokenResponse =
        await OAuth2PkceUtil(
          config: config.oauth2PkceServerConfig,
        ).exchangeCodeForToken(
          code: code,
          codeVerifier: codeVerifier,
          redirectUri: redirectUri,
        );

    final idToken = tokenResponse.raw['id_token'] as String?;
    if (idToken == null) {
      session.logAndThrow('Missing id_token in Google token response');
    }

    return (accessToken: tokenResponse.accessToken, idToken: idToken);
  } on OAuth2Exception catch (e) {
    session.log(e.toString(), level: LogLevel.debug);
    throw GoogleIdTokenVerificationException();
  }
}