How to handle invalid SSL certificates with Apache

Question

I know, there are many different questions and so many answers about this problem... But I can't understand...

I have: ubuntu-9.10-desktop-amd64 + NetBeans6.7.1 installed "as is" from off. rep. I need connecting to some site over the HTTPS. For this I use Apache's HttpClient.

From tutorial I read:

"Once you have JSSE correctly installed, secure HTTP communication over SSL should be as
simple as plain HTTP communication." And some example:

HttpClient httpclient = new HttpClient();
GetMethod httpget = new GetMethod("https://www.verisign.com/"); 
try { 
  httpclient.executeMethod(httpget);
  System.out.println(httpget.getStatusLine());
} finally {
  httpget.releaseConnection();
}

By now, I write this:

HttpClient client = new HttpClient();

HttpMethod get = new GetMethod("https://mms.nw.ru");
//get.setDoAuthentication(true);

try {
    int status = client.executeMethod(get);
    System.out.println(status);

    BufferedInputStream is = new BufferedInputStream(get.getResponseBodyAsStream());
    int r=0;byte[] buf = new byte[10];
    while((r = is.read(buf)) > 0) {
        System.out.write(buf,0,r);
    }

} catch(Exception ex) {
    ex.printStackTrace();
}

As a result I have a set of errors:

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 sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
        at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1627)
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:204)
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:198)
        at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:994)
        at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:142)
        at sun.security.ssl.Handshaker.processLoop(Handshaker.java:533)
        at sun.security.ssl.Handshaker.process_record(Handshaker.java:471)
        at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:904)
        at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1132)
        at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:643)
        at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:78)
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
        at org.apache.commons.httpclient.HttpConnection.flushRequestOutputStream(HttpConnection.java:828)
        at org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:2116)
        at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:1096)
        at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:398)
        at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
        at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
        at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
        at simpleapachehttp.Main.main(Main.java:41)
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:302)
        at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:205)
        at sun.security.validator.Validator.validate(Validator.java:235)
        at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:147)
        at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:230)
        at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:270)
        at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:973)
        ... 17 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:191)
        at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:255)
        at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:297)
        ... 23 more

What have I to do to create simplest SSL connection? (Probably without KeyManager and Trust manager etc. while.)

Answer 1

I'm useing httpclient 3.1.X ,and this works for me

        try {
        SSLContext sslContext = SSLContext.getInstance("TLS");
        TrustManager trustManager = new X509TrustManager() {
            @Override
            public void checkClientTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
            }

            @Override
            public void checkServerTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {

            }

            @Override
            public X509Certificate[] getAcceptedIssuers() {
                return null;
            }
        };
        sslContext.init(null, new TrustManager[]{trustManager}, null);
        SslContextSecureProtocolSocketFactory socketFactory = new SslContextSecureProtocolSocketFactory(sslContext,false);
        Protocol.registerProtocol("https", new Protocol("https", (ProtocolSocketFactory) socketFactory, 443));//同样会影响到HttpUtils
    } catch (Throwable e) {
        e.printStackTrace();

}

public class SslContextSecureProtocolSocketFactory implements      SecureProtocolSocketFactory {

private SSLContext sslContext;
private boolean verifyHostname;

public SslContextSecureProtocolSocketFactory(SSLContext sslContext, boolean verifyHostname) {
    this.verifyHostname = true;
    this.sslContext = sslContext;
    this.verifyHostname = verifyHostname;
}

public SslContextSecureProtocolSocketFactory(SSLContext sslContext) {
    this(sslContext, true);
}

public SslContextSecureProtocolSocketFactory(boolean verifyHostname) {
    this((SSLContext)null, verifyHostname);
}

public SslContextSecureProtocolSocketFactory() {
    this((SSLContext)null, true);
}

public synchronized void setHostnameVerification(boolean verifyHostname) {
    this.verifyHostname = verifyHostname;
}

public synchronized boolean getHostnameVerification() {
    return this.verifyHostname;
}

public Socket createSocket(String host, int port, InetAddress clientHost, int clientPort) throws IOException, UnknownHostException {
    SSLSocketFactory sf = this.getSslSocketFactory();
    SSLSocket sslSocket = (SSLSocket)sf.createSocket(host, port, clientHost, clientPort);
    this.verifyHostname(sslSocket);
    return sslSocket;
}

public Socket createSocket(String host, int port, InetAddress localAddress, int localPort, HttpConnectionParams params) throws IOException, UnknownHostException, ConnectTimeoutException {
    if(params == null) {
        throw new IllegalArgumentException("Parameters may not be null");
    } else {
        int timeout = params.getConnectionTimeout();
        Socket socket = null;
        SSLSocketFactory socketfactory = this.getSslSocketFactory();
        if(timeout == 0) {
            socket = socketfactory.createSocket(host, port, localAddress, localPort);
        } else {
            socket = socketfactory.createSocket();
            InetSocketAddress localaddr = new InetSocketAddress(localAddress, localPort);
            InetSocketAddress remoteaddr = new InetSocketAddress(host, port);
            socket.bind(localaddr);
            socket.connect(remoteaddr, timeout);
        }

        this.verifyHostname((SSLSocket)socket);
        return socket;
    }
}

public Socket createSocket(String host, int port) throws IOException, UnknownHostException {
    SSLSocketFactory sf = this.getSslSocketFactory();
    SSLSocket sslSocket = (SSLSocket)sf.createSocket(host, port);
    this.verifyHostname(sslSocket);
    return sslSocket;
}

public Socket createSocket(Socket socket, String host, int port, boolean autoClose) throws IOException, UnknownHostException {
    SSLSocketFactory sf = this.getSslSocketFactory();
    SSLSocket sslSocket = (SSLSocket)sf.createSocket(socket, host, port, autoClose);
    this.verifyHostname(sslSocket);
    return sslSocket;
}

private void verifyHostname(SSLSocket socket) throws SSLPeerUnverifiedException, UnknownHostException {
    synchronized(this) {
        if(!this.verifyHostname) {
            return;
        }
    }

    SSLSession session = socket.getSession();
    String hostname = session.getPeerHost();

    try {
        InetAddress.getByName(hostname);
    } catch (UnknownHostException var10) {
        throw new UnknownHostException("Could not resolve SSL sessions server hostname: " + hostname);
    }

    X509Certificate[] certs = (X509Certificate[])((X509Certificate[])session.getPeerCertificates());
    if(certs != null && certs.length != 0) {
        X500Principal subjectDN = certs[0].getSubjectX500Principal();
        List cns = this.getCNs(subjectDN);
        boolean foundHostName = false;
        Iterator i$ = cns.iterator();
        AntPathMatcher matcher  = new AntPathMatcher();
        while(i$.hasNext()) {
            String cn = (String)i$.next();
            if(matcher.match(cn.toLowerCase(),hostname.toLowerCase())) {
                foundHostName = true;
                break;
            }
        }

        if(!foundHostName) {
            throw new SSLPeerUnverifiedException("HTTPS hostname invalid: expected \'" + hostname + "\', received \'" + cns + "\'");
        }
    } else {
        throw new SSLPeerUnverifiedException("No server certificates found!");
    }
}

private List<String> getCNs(X500Principal subjectDN) {
    ArrayList cns = new ArrayList();
    StringTokenizer st = new StringTokenizer(subjectDN.getName(), ",");

    while(st.hasMoreTokens()) {
        String cnField = st.nextToken();
        if(cnField.startsWith("CN=")) {
            cns.add(cnField.substring(3));
        }
    }

    return cns;
}

protected SSLSocketFactory getSslSocketFactory() {
    SSLSocketFactory sslSocketFactory = null;
    synchronized(this) {
        if(this.sslContext != null) {
            sslSocketFactory = this.sslContext.getSocketFactory();
        }
    }

    if(sslSocketFactory == null) {
        sslSocketFactory = (SSLSocketFactory)SSLSocketFactory.getDefault();
    }

    return sslSocketFactory;
}

public synchronized void setSSLContext(SSLContext sslContext) {
    this.sslContext = sslContext;
}

}

Answer 2

follow the instruction given below for Java 1.7, to create an SSL certificate using InstallCert.java program file.

https://github.com/escline/InstallCert

you must restart the tomcat

Answer 3

https://mms.nw.ru likely uses a certificate not issued by a certification authority. Consequently, you need to add the certificate to your trusted Java key store as explained in unable to find valid certification path to requested target:

When working on a client that works with an SSL enabled server running in https protocol, you could get error 'unable to find valid certification path to requested target' if the server certificate is not issued by certification authority, but a self signed or issued by a private CMS.

Don't panic. All you need to do is to add the server certificate to your trusted Java key store if your client is written in Java. You might be wondering how as if you can not access the machine where the server is installed. There is a simple program can help you. Please download the Java program and run

% java InstallCert _web_site_hostname_

This program opened a connection to the specified host and started an SSL handshake. It printed the exception stack trace of the error that occured and shows you the certificates used by the server. Now it prompts you add the certificate to your trusted KeyStore.

If you've changed your mind, enter 'q'. If you really want to add the certificate, enter '1', or other numbers to add other certificates, even a CA certificate, but you usually don't want to do that. Once you have made your choice, the program will display the complete certificate and then added it to a Java KeyStore named 'jssecacerts' in the current directory.

To use it in your program, either configure JSSE to use it as its trust store or copy it into your $JAVA_HOME/jre/lib/security directory. If you want all Java applications to recognize the certificate as trusted and not just JSSE, you could also overwrite the cacerts file in that directory.

After all that, JSSE will be able to complete a handshake with the host, which you can verify by running the program again.

To get more details, you can check out Leeland's blog No more 'unable to find valid certification path to requested target'