HTTPS and Java

[Matthew Mellott]

So I've been trying to post to this url. Every diffrent way I try it I get the same errors:

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:1623)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:198)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:192)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1074)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:128)
	at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Handshaker.java:529)
	at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Handshaker.java:465)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:884)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1120)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1147)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1131)
	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.getInputStream(HttpURLConnection.java:1049)
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:234)
	at MtGox.main(MtGox.java:58)
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:294)
	at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:200)
	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:1053)
	... 12 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:289)
	... 18 more

I have no idea what these errors mean, let alone how to fix them. Here's my code:

import java.net.URL;
import java.io.*;
import javax.net.ssl.HttpsURLConnection;

public class MtGox {
	public static void main(String[] args) throws Exception {
		String httpsURL = "https://mtgox.com/api/0/data/ticker.php";
		URL myurl = new URL(httpsURL);
		HttpsURLConnection con = (HttpsURLConnection) myurl.openConnection();
		InputStream ins = con.getInputStream();
		InputStreamReader isr = new InputStreamReader(ins);
		BufferedReader in = new BufferedReader(isr);

		String inputLine;

		while ((inputLine = in.readLine()) != null) {
			System.out.println(inputLine);
		}

		in.close();
	}

}

I've used the SSLSocket class before without getting this error. I also tried implementing the above code using an SSLSocket and got identical errors to the ones above.
Thanks for the help!

[Ulf Dittmer]

You're in luck: that's a FAQ - the SecurityFaq answers it.

[Unnar Björnsson]

I've never done any http work with java but it seems to me that the site you are requesting https connection is missing or has expired SSL certificate. If you request webpage through https that has no SSL via browser the browser emits a warning. You can add an exception to that site if you want to, similarly (assuming that my first assumption about this exception is correct) you should be able to ignore this exception by putting the corresponding code in a try-catch block.