why is facebook login fragment always showing invalid key hash in android?

Question

I am trying to login through facebook login in my android app but it is always giving me an invalid key hash. I have generated the hash key properly through the terminal on my mac using the command given at the facebook developer site and also used my facebook application id properly.Here is my code for the login activity class:

LoginActivity.java

package com.titmus.worldscope;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.Signature;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Base64;
import android.util.Log;
import android.webkit.WebView;
import android.widget.Toast;

import com.facebook.AccessToken;
import com.titmus.worldscope.model.WorldScopeUser;
import com.titmus.worldscope.utility.WorldScopeAPIService;
import com.titmus.worldscope.utility.WorldScopeRestAPI;

import java.security.MessageDigest;

import fragment.FacebookLoginFragment;

import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;

public class LoginActivity extends AppCompatActivity implements FacebookLoginFragment.OnFragmentInteractionListener {

    private static final String TAG = "LoginActivity";
    private static final String WELCOME_GIF_LINK = "file:///android_asset/welcomeGifAssets/welcome.html";
    private static final String APP_SERVER_AUTH_FAILED_MSG = "Authentication with WorldScope's server has failed, please check that you have internet connections and try again.";
    private static Context context;
    private FacebookLoginFragment facebookLoginFragment;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_facebook_login);

        context = this;

        loadGifIntoWebView();
    }

    @Override
    public void onFacebookLoginSuccess(AccessToken accessToken) {
        // Successful login -> Redirect to Main activity
        Log.d(TAG, "Login Success!");
        Log.d(TAG, "AccessToken: " + accessToken.getToken());

        // Instantiate and make a call to login user into WorldScope servers
        Call<WorldScopeUser> call = new WorldScopeRestAPI(context).buildWorldScopeAPIService().loginUser(new WorldScopeAPIService.LoginUserRequest(accessToken.getToken()));
        call.enqueue(new Callback<WorldScopeUser>() {
            @Override
            public void onResponse(Response<WorldScopeUser> response) {
                if(response.isSuccess()) {
                    Log.d(TAG, "Success!");
                    Log.d(TAG, "" + response.body().toString());

                    WorldScopeUser user = response.body();
                    WorldScopeAPIService.setUser(user);
                    // Redirect to MainActivity if successful
                    redirectToMainActivity();

                } else {
                    Log.d(TAG, "Failure" + response.code() + ": " + response.message());
                    // Logout of Facebook
                    logoutOfFacebook();
                }
            }

            @Override
            public void onFailure(Throwable t) {
                Log.d(TAG, "Failure: " + t.getMessage());
                // Logout of Facebook
                logoutOfFacebook();
            }
        });
    }

    //Redirects to MainActivity
    protected void redirectToMainActivity() {
        Intent intent = new Intent(context, MainActivity.class);
        intent.putExtra("activity", TAG);
        startActivity(intent);
    }

    // Called to logout of Facebook when attempt to authenticate with App server fails
    private void logoutOfFacebook() {

        if(facebookLoginFragment == null) {
            // Get FacebookLoginFragment if missing
            facebookLoginFragment = (FacebookLoginFragment) getSupportFragmentManager().findFragmentById(R.id.facebookLoginButtonFragment);
        }

        // Toast to inform user
        Toast toast = Toast.makeText(context, APP_SERVER_AUTH_FAILED_MSG, Toast.LENGTH_LONG);
        toast.show();
        facebookLoginFragment.logoutFromFacebook();

    }

    // Method to load Gif's html data into WebView
    private void loadGifIntoWebView() {
        WebView welcomeGifWebView = (WebView) findViewById(R.id.welcomeGifWebView);
        welcomeGifWebView.loadUrl(WELCOME_GIF_LINK);
    }
}

activity_facebook_login.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/loginActivity"
    tools:context="com.titmus.worldscope.LoginActivity">

    <WebView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/welcomeGifWebView"
        android:layout_alignParentEnd="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true" />

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/facebookLoginButtonFragment"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="48dp">

        <ImageView
            android:layout_width="32dp"
            android:layout_height="match_parent"
            android:id="@+id/imageView"
            android:src="@drawable/ic_logo"
            android:layout_alignBottom="@+id/textView4"
            android:layout_toStartOf="@+id/textView4"
            android:layout_marginEnd="4dp"
            android:paddingTop="6dp"
            android:paddingBottom="5dp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="WorldScope"
            android:id="@+id/textView4"
            android:textColor="#ffffff"
            android:textStyle="bold"
            android:textSize="32sp"
            android:layout_above="@+id/facebookLoginButtonFragment"
            android:layout_centerHorizontal="true" />
    </LinearLayout>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="By logging in you agree to WorldScope&apos;s Privacy Policy and Terms of Use."
        android:id="@+id/textView6"
        android:textColor="#eeeeee"
        android:textSize="14dp"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:textAlignment="center"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="57dp" />

    <fragment
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:name="fragment.FacebookLoginFragment"
        android:id="@+id/facebookLoginButtonFragment"
        tools:layout="@layout/fragment_facebook_login"
        android:layout_marginBottom="14dp"
        android:layout_above="@+id/textView6"
        android:layout_alignParentStart="true" />

</RelativeLayout>

Answer 1

The keyhash generated using cmd works fine for the first then it doesn't.

So use this method to generate keyHash in any of you class

public void printHashKey(){
        // Add code to print out the key hash
        try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    "net.simplifiedcoding.androidlogin",
                    PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
            }
        } catch (PackageManager.NameNotFoundException e) {

        } catch (NoSuchAlgorithmException e) {

        }
    }

Then copy the key hash genrated, and paste it where you added keyhash generated by cmd in facebook developer console.

It will work, and dont restrict the application to only one device in facebook developer console