Question

I have to call an HTTP service hosted on web server with an invalid SSL certificate. In dev, I’m importing the certificate with keytool but the certificate will be different on each client install, so I can’t just bundle it.

Foreword: I DO know that skipping SSL validation is really ugly. In this specific case, I would not even need SSL and all other communications in the system are over simple HTTP. So I really don’t care about MITM attacks or such. An attacker would not need to go as far as to break SSL because there is no SSL for the data. This is support for a legacy system over which I have no control.

I’m using HttpURLConnection with an SSLSocketFactory that has a NaiveTrustManager and a NaiveHostnameVerifier. This works on some self-signed servers I tried but not on the customer’s site. The error I’m getting is:

javax.net.ssl.SSLKeyException: [Security:090477]Certificate chain received from xxxxxxxxxx was not trusted causing SSL handshake failure.
    at com.certicom.tls.interfaceimpl.TLSConnectionImpl.fireException(Unknown Source)
    at com.certicom.tls.interfaceimpl.TLSConnectionImpl.fireAlertSent(Unknown Source)
    at com.certicom.tls.record.handshake.HandshakeHandler.fireAlert(Unknown Source)
    at com.certicom.tls.record.handshake.HandshakeHandler.fireAlert(Unknown Source)
    at com.certicom.tls.record.handshake.ClientStateReceivedServerHello.handle(Unknown Source)
    at com.certicom.tls.record.handshake.HandshakeHandler.handleHandshakeMessage(Unknown Source)
    at com.certicom.tls.record.handshake.HandshakeHandler.handleHandshakeMessages(Unknown Source)
    at com.certicom.tls.record.MessageInterpreter.interpretContent(Unknown Source)
    at com.certicom.tls.record.MessageInterpreter.decryptMessage(Unknown Source)
    at com.certicom.tls.record.ReadHandler.processRecord(Unknown Source)
    at com.certicom.tls.record.ReadHandler.readRecord(Unknown Source)
    at com.certicom.tls.record.ReadHandler.readUntilHandshakeComplete(Unknown Source)
    at com.certicom.tls.interfaceimpl.TLSConnectionImpl.completeHandshake(Unknown Source)
    at com.certicom.tls.record.WriteHandler.write(Unknown Source)
    at com.certicom.io.OutputSSLIOStreamWrapper.write(Unknown Source)
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
    at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
    at java.io.FilterOutputStream.flush(FilterOutputStream.java:123)
    at weblogic.net.http.HttpURLConnection.writeRequests(HttpURLConnection.java:154)
    at weblogic.net.http.HttpURLConnection.getInputStream(HttpURLConnection.java:358)
    at weblogic.net.http.SOAPHttpsURLConnection.getInputStream(SOAPHttpsURLConnection.java:37)
    at weblogic.net.http.HttpURLConnection.getResponseCode(HttpURLConnection.java:947)
    at (my own code)

My SimpleSocketFactory looks like:

public static final SSLSocketFactory getSocketFactory()
{
    if ( sslSocketFactory == null ) {
        try {
            // get ssl context
            SSLContext sc = SSLContext.getInstance("SSL");

            // Create a trust manager that does not validate certificate chains
            TrustManager[] trustAllCerts = new TrustManager[]{
                new NaiveTrustManager() {
                    public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                        log.debug("getAcceptedIssuers");
                        return new java.security.cert.X509Certificate[0];
                    }
                    public void checkClientTrusted(
                        java.security.cert.X509Certificate[] certs, String authType) {
                        log.debug("checkClientTrusted");
                    }
                    public void checkServerTrusted(
                        java.security.cert.X509Certificate[] certs, String authType) {
                        log.debug("checkServerTrusted");
                    }
                }
            };

            sc.init(null, trustAllCerts, new java.security.SecureRandom());
            // EDIT: fixed the following line that was redeclaring SSLSocketFactory sslSocketFactory, returning null every time. Same result though.
            sslSocketFactory = sc.getSocketFactory();

            HttpsURLConnection.setDefaultSSLSocketFactory(sslSocketFactory);
            // EDIT: The following line has no effect
            //HttpsURLConnection.setDefaultHostnameVerifier(new NaiveHostNameVerifier());

        } catch (KeyManagementException e) {
            log.error ("No SSL algorithm support: " + e.getMessage(), e);
        } catch (NoSuchAlgorithmException e) {
            log.error ("Exception when setting up the Naive key management.", e);
        }
    }
    return sslSocketFactory;
}

The NaiveHostnameVerifier has a way to limit the valid hosts but it’s left null, so basically accepting anything:

public class NaiveHostnameVerifier implements HostnameVerifier {
    String[] patterns;

    public NaiveHostnameVerifier () {
        this.patterns=null;
    }

    public NaiveHostnameVerifier (String[] patterns) {
        this.patterns = patterns;
    }

    public boolean verify(String urlHostName,SSLSession session) {
        if (patterns==null || patterns.length==0) {
            return true;
        } else {
            for (String pattern : patterns) {
                if (urlHostName.matches(pattern)) {
                    return true;
                }
            }
            return false;
        }
    }
}

The usage is like this:

    try {
        conn = (HttpURLConnection)url.openConnection();
        if (conn instanceof HttpsURLConnection) {
                ((HttpsURLConnection)conn).setSSLSocketFactory(SimpleSSLSocketFactory.getSocketFactory());
                // EDIT: added this line, the HV has to be set on connection, not on the factory.
                ((HttpsURLConnection)conn).setHostnameVerifier(new NaiveHostnameVerifier());
        }
        conn.setDoInput(true);
        conn.setDoOutput(true);
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-type","application/x-www-form-urlencoded");
        conn.connect();

        StringBuffer sbContent = new StringBuffer();
        // (snip)
        DataOutputStream stream = new DataOutputStream(conn.getOutputStream ());
        stream.writeBytes(sbContent.toString());
        stream.flush();
        stream.close();
    } catch (ClassCastException e) {
        log.error("The URL does not seem to point to a HTTP connection");
        return null;
    } catch (IOException e) {
        log.error("Error accessing the requested URL", e);
        return null;
    }

When I’m searching on the error message, most people just import the certificate in their store but again, I can’t really do that because I don’t know which certificate it’ll be. My only alternative if this doesn’t work is to make a tool that can download the certificate and add it in an easier way that cryptic command lines but I’d rather let my Java code just ignore the invalid certificate.

Any idea ?

Answer 1

There is in fact nothing wrong with the code above. The problem seems to lie with Weblogic and this Certicom TLS module. When I look at the server options, SSL and Advanced I see that I can specify a custom HostnameVerifier (SSLMBean.HostnameVerifier) but the only element suggesting the ability to interfere with Certificate validation is deprecated.

I tried the above code outside of Weblogic and it worked beautifully (fixed the HostnameVerifier in the post though).

Then I tried to add “-DUseSunHttpHandler=true” to the Weblogic parameters as suggested by ipolevoy in this other question. It started working.

That being said, switching the HTTP handler on an Oracle Service Bus server seems a bit risky. There might well be side-effects that come back to bite me in a few weeks time…

I also attempted to define my own trustStore and point it to a jssecacert that contained the required key. It was also ignored by Weblogic because it has its own setting of the trustStore for each server. So I’m resorting to ask the administrator to manually import the required keys or point Weblogic to my own store.