isFirebaseToken method
Validates a Firebase JWT token structure
Implementation
bool isFirebaseToken(String token) {
try {
final parts = token.split('.');
if (parts.length != 3) return false;
// Try to decode the header and payload
final header = json.decode(utf8.decode(base64Url.decode(parts[0])));
final payload = json.decode(utf8.decode(base64Url.decode(parts[1])));
// Check for Firebase-specific claims
return header['alg'] != null &&
payload['iss'] != null &&
payload['aud'] != null &&
payload['exp'] != null;
} catch (e) {
return false;
}
}