How to Handle Self-Signed Certificates in Android WebView

Advanced Configuration for Self-Signed Certificates in Android WebView

When it comes to self signed certificate android configurations, developers are likely to encounter issues such as ERR_CERT_AUTHORITY_INVALID or NET::ERR_CERT_REVOKED. These errors are due to the fact that Android WebView, by default, rejects certificates that are not signed by a trusted Certificate Authority (CA). In this article, we will discuss advanced ways to configure WebView for self-signed certificates.

Step-by-Step Guide to Handle Self-Signed Certificates in Android WebView

The following is a step-by-step guide on how to enable Android WebView to accept self-signed certificates. We will be providing code samples and explanations for each step.

Step 1: Create a Self-Signed Certificate

Before diving into Android WebView, you’ll need a self-signed certificate. You can generate one using OpenSSL:

openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes

Step 2: Configure Android WebView to Accept Self-Signed Certificates

To bypass SSL errors in Android WebView, you’ll need to override the onReceivedSslError method in WebViewClient.

Here’s how:

import android.net.http.SslError;
import android.os.Bundle;
import android.webkit.SslErrorHandler;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        WebView webView = new WebView(this);
        setContentView(webView);

        webView.setWebViewClient(new WebViewClient() {
            @Override
            public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
                // Bypass SSL errors (use with caution!)
                handler.proceed();
            }
        });

        // Load your URL with the self-signed certificate
        webView.loadUrl("https://your-local-server.com");
    }
}

Step 3: Implementing Certificate Pinning for Enhanced Security

While bypassing SSL errors can resolve android webview ssl error issues, it’s not secure for production environments. A better approach is to implement certificate pinning, which ensures that your app only accepts specific certificates.

@Override
public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
    // Validate the certificate before proceeding
    if (isCertificateValid(error.getCertificate())) {
        handler.proceed();
    } else {
        handler.cancel();
    }
}

private boolean isCertificateValid(SslCertificate certificate) {
    // Compare the certificate with your self-signed certificate
    String expectedIssuer = "CN=YourSelfSignedCertificate";
    return certificate.getIssuedBy().getDName().equals(expectedIssuer);
}

Step 4: Using Network Security Configuration (Android 7.0+)

For apps targeting Android 7.0 (Nougat) and above, you can use the Network Security Configuration feature to handle self-signed certificates. This approach is more secure than bypassing SSL errors in code.

Steps:

<network-security-config> 
 <domain-config> 
   <domain includeSubdomains="true">your-local-server.com</domain> 
   <trust-anchors> 
    <certificates src="@raw/self_signed_cert"/> 
   </trust-anchors> 
  </domain-config> 
</network-security-config>

<application 
  android:networkSecurityConfig="@xml/network_security_config"
  ... > 
</application>

Step 5: Debugging SSL Errors in WebView

When debugging android webview ssl error issues, it’s essential to log detailed error information. This helps identify the root cause of SSL-related problems.

@Override
public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
    // Log the SSL error details
    Log.e("WebViewSSL", "SSL Error: " + error.toString());
    handler.proceed(); // Proceed for debugging purposes only
}

Common SSL Errors:

Some Innovative Applications of Self Signed Certificates

Final Thoughts

Managing self-signed certificates in Android WebView is a matter of understanding the need for security without overdoing it. You can easily address the android webview ssl error while preventing as many risks as possible by customizing WebViewClient, implementing certificate pinning, and using Network Security Configuration. It is always important to only use self-signed certificates properly and do not circumvent SSL errors in the production environment.

Frequently Asked Questions (FAQs)

How to solve SSL errors in Android WebView?

To solve SSL errors in Android WebView,  you can override the onReceivedSslError method of the WebViewClient and use handler.proceed()  to ignore the error. However, this should only be done for development purposes. For production, it  is recommended to use certificate pinning or CA signed certificates.

Can I use self signed certificates  in the product?

No, it is not recommended to use self signed certificates in the product. They  do not have the level of trust and assurance of Certificate Authorities (CAs) and are therefore  insecure. Always use CA signed certificates for release builds of the apps.

What is certificate pinning  in Android WebView?

Certificate pinning is the process of securing your app against man in the middle attacks  by only accepting certain certificates. It entails checking the validity of the server’s certificate against a given certificate  that is stored in the application.

How to create a self signed certificate for Android WebView?

You can create a self signed certificate using openssl like this:

openssl req  -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days  365 -nodes

What is the meaning of Network Security Configuration in Android?

Network Security Configuration  is a concept that was introduced in Android 7.0 (Nougat) and enables developers  to define network security options in an XML file. It can be employed to specify accepted certificates, which  may include self-signed certificates, for particular domains.

Why does Android WebView throw an error for  self-signed certificates?

Android WebView blocks self-signed certificates by default because they are not signed by a trusted  Certificate Authority (CA). This is done to ensure that users are protected from threats such as  eavesdropping.

Priya Mervana

Verified Web Security Experts

Priya Mervana is working at SSLInsights.com as a web security expert with over 10 years of experience writing about encryption, SSL certificates, and online privacy. She aims to make complex security topics easily understandable for everyday internet users.