How to Resolve SSLHandshakeException: No Appropriate Protocol in Java

How can I fix the SSLHandshakeException: No appropriate protocol when trying to connect to my HTTPS website in Java?

The SSLHandshakeException you're encountering when trying to establish a connection to your HTTPS website in Java occurs mainly due to incompatible SSL/TLS protocols or cipher suites. This guide will provide you with a step-by-step approach to resolve the problem and successfully connect to your website over HTTPS.

// Example of setting TLS versions via system properties
System.setProperty("https.protocols", "TLSv1.2,TLSv1.3");

// Example of cert manager implementation (only for illustration)
TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() { public java.security.cert.X509Certificate[] getAcceptedIssuers() { return new X509Certificate[0]; } public void checkClientTrusted(java.security.cert.X509Certificate[] certs, String authType) {} public void checkServerTrusted(java.security.cert.X509Certificate[] certs, String authType) {} }};
SSLContext sc = SSLContext.getInstance("TLS");
sc.init(null, trustAllCerts, new java.security.SecureRandom());
HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

// Note: It is not recommended to trust all certificates in production.

Causes

• Java 8 may be configured to disable certain SSL/TLS protocols or cipher suites that your server requires.
• There may be a mismatch between the SSL protocol version supported by the server and the client (Java in this case).
• Insufficient trust configuration on the JVM causing handshake failures when the server's certificate is verified.

Solutions

• Verify the supported TLS/SSL version on your web server and ensure it aligns with your Java application's configuration.
• Enable or upgrade to a supported protocol by adding the necessary Java system properties when launching your application, for example: `-Dhttps.protocols=TLSv1.2,TLSv1.3`.
• Ensure your Java installation has up-to-date security policies and root certificates; consider running `update-alternatives --config java` to point to the correct version.
• Review and modify your code's SSL handshake and trust manager setup, ensuring your implementation doesn't inadvertently disable necessary protocols.

Mistake: Not updating JVM to the latest version.

Solution: Always keep your Java Runtime Environment updated to ensure the latest security protocols and cipher suites are supported.

Mistake: Running a local solution with insecure options (trusting all certificates).

Solution: Do not use a custom TrustManager that bypasses SSL verification in production; ensure proper certificate validation.

Mistake: Misconfiguring URL or resource path in the application.

Solution: Double-check your URLs and the specific API or file paths you're trying to access. Ensure they are valid.