java - How to ignore PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException?

Question

I got the following exception when try to post a request to a http server:

Here is the code I used

URL url = new URL(
        "https://www.abc.com");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();

conn.setRequestMethod("GET");

conn.setDoOutput(true);

DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
// wr.writeBytes(params);
wr.flush();
wr.close();

BufferedReader br = new BufferedReader(new InputStreamReader(
        conn.getInputStream()));
String line = null;
while ((line = br.readLine()) != null) {
    System.out.println(line);
}

Here is the exception:

Exception in thread "main" javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:174)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1731)
    at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:241)
    at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:235)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1206)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:136)
    at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Handshaker.java:593)
    at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Handshaker.java:529)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:925)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1170)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1197)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1181)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:434)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:166)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1014)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(HttpsURLConnectionImpl.java:230)
    at com.amazon.mzang.tools.httpchecker.CategoryYank.getPV(CategoryYank.java:32)
    at com.amazon.mzang.tools.httpchecker.CategoryYank.main(CategoryYank.java:18)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:323)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:217)
    at sun.security.validator.Validator.validate(Validator.java:218)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:126)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:209)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:249)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1185)
    ... 13 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:174)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:238)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:318)
    ... 19 more

The server is not owned by me. Is there a way to ignore this exception?

Answer 1

I have used the below code to override the SSL checking in my project and it worked for me.

package com.beingjavaguys.testftp;

import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.net.URLConnection;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.security.cert.X509Certificate;

/**
 * Fix for Exception in thread "main" javax.net.ssl.SSLHandshakeException:
 * sun.security.validator.ValidatorException: PKIX path building failed:
 * sun.security.provider.certpath.SunCertPathBuilderException: unable to find
 * valid certification path to requested target
 */
public class ConnectToHttpsUrl {
    public static void main(String[] args) throws Exception {
        /* Start of Fix */
        TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() {
            public java.security.cert.X509Certificate[] getAcceptedIssuers() { return null; }
            public void checkClientTrusted(X509Certificate[] certs, String authType) { }
            public void checkServerTrusted(X509Certificate[] certs, String authType) { }

        } };

        SSLContext sc = SSLContext.getInstance("SSL");
        sc.init(null, trustAllCerts, new java.security.SecureRandom());
        HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

        // Create all-trusting host name verifier
        HostnameVerifier allHostsValid = new HostnameVerifier() {
            public boolean verify(String hostname, SSLSession session) { return true; }
        };
        // Install the all-trusting host verifier
        HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);
        /* End of the fix*/

        URL url = new URL("https://nameofthesecuredurl.com");
        URLConnection con = url.openConnection();
        Reader reader = new InputStreamReader(con.getInputStream());
        while (true) {
            int ch = reader.read();
            if (ch == -1) 
                break;
            System.out.print((char) ch);
        }
    }
}