Primer paso de la investigacion. Se aportan el .apk, las carpetas con el apk extraido y el apk descompilado. El archivo API_DOCUMENTATION.md es un archivo donde se anotaran los descubrimientos del funcionamiento de la API, y los .py son scripts para probar la funcionalidad de la API con los métodos que vayamos encontrando. Finalmente, los archivos .js son scripts de Frida para extraer informacion de la APP durante la ejecucion.

apk_decompiled/sources/com/google/firebase/FirebaseError.java

@@ -0,0 +1,89 @@
+package com.google.firebase;
+
+import com.google.android.gms.common.annotation.KeepForSdk;
+
+@KeepForSdk
+/* loaded from: classes3.dex */
+public class FirebaseError {
+
+    @KeepForSdk
+    public static final int ERROR_ACCOUNT_EXISTS_WITH_DIFFERENT_CREDENTIAL = 17012;
+
+    @KeepForSdk
+    public static final int ERROR_APP_NOT_AUTHORIZED = 17028;
+
+    @KeepForSdk
+    public static final int ERROR_CREDENTIAL_ALREADY_IN_USE = 17025;
+
+    @KeepForSdk
+    public static final int ERROR_CUSTOM_TOKEN_MISMATCH = 17002;
+
+    @KeepForSdk
+    public static final int ERROR_EMAIL_ALREADY_IN_USE = 17007;
+
+    @KeepForSdk
+    public static final int ERROR_INTERNAL_ERROR = 17499;
+
+    @KeepForSdk
+    public static final int ERROR_INVALID_API_KEY = 17023;
+
+    @KeepForSdk
+    public static final int ERROR_INVALID_CREDENTIAL = 17004;
+
+    @KeepForSdk
+    public static final int ERROR_INVALID_CUSTOM_TOKEN = 17000;
+
+    @KeepForSdk
+    public static final int ERROR_INVALID_EMAIL = 17008;
+
+    @KeepForSdk
+    public static final int ERROR_INVALID_USER_TOKEN = 17017;
+
+    @KeepForSdk
+    public static final int ERROR_NETWORK_REQUEST_FAILED = 17020;
+
+    @KeepForSdk
+    public static final int ERROR_NO_SIGNED_IN_USER = 17495;
+
+    @KeepForSdk
+    public static final int ERROR_NO_SUCH_PROVIDER = 17016;
+
+    @KeepForSdk
+    public static final int ERROR_OPERATION_NOT_ALLOWED = 17006;
+
+    @KeepForSdk
+    public static final int ERROR_PROVIDER_ALREADY_LINKED = 17015;
+
+    @KeepForSdk
+    public static final int ERROR_REQUIRES_RECENT_LOGIN = 17014;
+
+    @KeepForSdk
+    public static final int ERROR_TOO_MANY_REQUESTS = 17010;
+
+    @KeepForSdk
+    public static final int ERROR_USER_DISABLED = 17005;
+
+    @KeepForSdk
+    public static final int ERROR_USER_MISMATCH = 17024;
+
+    @KeepForSdk
+    public static final int ERROR_USER_NOT_FOUND = 17011;
+
+    @KeepForSdk
+    public static final int ERROR_USER_TOKEN_EXPIRED = 17021;
+
+    @KeepForSdk
+    public static final int ERROR_WEAK_PASSWORD = 17026;
+
+    @KeepForSdk
+    public static final int ERROR_WRONG_PASSWORD = 17009;
+    private int errorCode;
+
+    public FirebaseError(int i) {
+        this.errorCode = i;
+    }
+
+    public int getErrorCode() {
+        return this.errorCode;
+    }
+}