Last week Alistair and I were working on an internal application and we needed to make a HTTPS request directly to an AWS machine using a certificate signed to a different host.

We use jersey-client so our code looked something like this:

Client client = Client.create();
 
client.resource("https://some-aws-host.compute-1.amazonaws.com").post();
// and so on

When we ran this we predictably ran into trouble:

com.sun.jersey.api.client.ClientHandlerException: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative DNS name matching some-aws-host.compute-1.amazonaws.com found.
	at com.sun.jersey.client.urlconnection.URLConnectionClientHandler.handle(URLConnectionClientHandler.java:149)
	at com.sun.jersey.api.client.Client.handle(Client.java:648)
	at com.sun.jersey.api.client.WebResource.handle(WebResource.java:670)
	at com.sun.jersey.api.client.WebResource.post(WebResource.java:241)
	at com.neotechnology.testlab.manager.bootstrap.ManagerAdmin.takeBackup(ManagerAdmin.java:33)
	at com.neotechnology.testlab.manager.bootstrap.ManagerAdminTest.foo(ManagerAdminTest.java:11)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:202)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:65)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative DNS name matching some-aws-host.compute-1.amazonaws.com found.
	at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
	at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1884)
	at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:276)
	at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:270)
	at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1341)
	at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:153)
	at sun.security.ssl.Handshaker.processLoop(Handshaker.java:868)
	at sun.security.ssl.Handshaker.process_record(Handshaker.java:804)
	at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1016)
	at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1312)
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1339)
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1323)
	at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:563)
	at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1300)
	at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:468)
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:338)
	at com.sun.jersey.client.urlconnection.URLConnectionClientHandler._invoke(URLConnectionClientHandler.java:240)
	at com.sun.jersey.client.urlconnection.URLConnectionClientHandler.handle(URLConnectionClientHandler.java:147)
	... 31 more
Caused by: java.security.cert.CertificateException: No subject alternative DNS name matching some-aws-host.compute-1.amazonaws.com found.
	at sun.security.util.HostnameChecker.matchDNS(HostnameChecker.java:191)
	at sun.security.util.HostnameChecker.match(HostnameChecker.java:93)
	at sun.security.ssl.X509TrustManagerImpl.checkIdentity(X509TrustManagerImpl.java:347)
	at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:203)
	at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:126)
	at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1323)
	... 45 more

We figured that we needed to get our client to ignore the certificate and came across this Stack Overflow thread which had some suggestions on how to do this.

None of the suggestions worked on their own but we ended up with a combination of a couple of the suggestions which did the trick:

public Client hostIgnoringClient() {
    try
    {
        SSLContext sslcontext = SSLContext.getInstance( "TLS" );
        sslcontext.init( null, null, null );
        DefaultClientConfig config = new DefaultClientConfig();
        Map<String, Object> properties = config.getProperties();
        HTTPSProperties httpsProperties = new HTTPSProperties(
                new HostnameVerifier()
                {
                    @Override
                    public boolean verify( String s, SSLSession sslSession )
                    {
                        return true;
                    }
                }, sslcontext
        );
        properties.put( HTTPSProperties.PROPERTY_HTTPS_PROPERTIES, httpsProperties );
        config.getClasses().add( JacksonJsonProvider.class );
        return Client.create( config );
    }
    catch ( KeyManagementException | NoSuchAlgorithmException e )
    {
        throw new RuntimeException( e );
    }
}

You’re welcome Future Mark.