Q1. What are some of the issues you encounter with SSL handshake?
A1. Some of the issues you try to debug are
- Presence of a valid certificate in trust store
- Incorrect certificate chains in the client or server truststore
- Invalid key algorithm used for private keys
- Expired certificate
- Incorrect passwords used to access the keys
- Multiple private keys to choose from
Q2. How does your SSL client look for the right certificate in a truststore?
A2. The client needs to have the truststore configured in any one of following ways and appropriate certificate imported into it.
Option 1: Specify it for a specific SSL connection via configuration files. For example, cxf.xml may look like
Example 1:
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<http:conduit name="https://.*/myapp-ws/.*"> <http:tlsClientParameters> <sec:trustManagers> <sec:keyStore type="JKS" password="trust.pass" file="/opt2/jbossprd/jboss-4.2.0.GA/server/myapp/conf/app-specific.keystore" /> </sec:trustManagers> <sec:cipherSuitesFilter> <sec:include>.*_EXPORT_.*</sec:include> <sec:include>.*_EXPORT1024_.*</sec:include> <sec:include>.*_WITH_DES_.*</sec:include> <sec:include>.*_WITH_NULL_.*</sec:include> <sec:include>.*_RSA_WITH_.*</sec:include> <sec:exclude>.*_DH_anon_.*</sec:exclude> </sec:cipherSuitesFilter> </http:tlsClientParameters> <http:client ReceiveTimeout="180000" AutoRedirect="true" Connection="close" /> </http:conduit> |
Example 2:
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<bean id="ecmServiceRequestServiceRestTemplate" class="org.springframework.web.client.RestTemplate"> <property name="messageConverters"> <list> <bean class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter" /> <bean class="org.springframework.http.converter.xml.SourceHttpMessageConverter" /> </list> </property> <property name="requestFactory" ref="customSslHttpClientHttpRequestFactory" /> </bean> |
where you can define your “customSslHttpClientHttpRequestFactory” and supply the paths to keystore and trusstore locations.
Option 2: On the application server start up with a JVM argument
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-Djavax.net.ssl.trustStore=/Tools/java/keystore/myapp.keystore |
Option 3: When none of the above is specified, it defaults to your cacerts or jssecacerts
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%JAVA_HOME%/jre/lib/security/cacerts |
Q3. What are some of the tools you use to go about identifying and fixing SSL issues?
A3.
1. SSLPoke Java Utility
Step 1: Get the handy java file from the atlassian
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import javax.net.ssl.SSLSocket; import javax.net.ssl.SSLSocketFactory; import java.io.*; /** Establish a SSL connection to a host and port, writes a byte and * prints the response. See * http://confluence.atlassian.com/display/JIRA/Connecting+to+SSL+services */ public class SSLPoke { public static void main(String[] args) { if (args.length != 2) { System.out.println("Usage: "+SSLPoke.class.getName()+" <host> <port>"); System.exit(1); } try { SSLSocketFactory sslsocketfactory = (SSLSocketFactory) SSLSocketFactory.getDefault(); SSLSocket sslsocket = (SSLSocket) sslsocketfactory.createSocket(args[0], Integer.parseInt(args[1])); InputStream in = sslsocket.getInputStream(); OutputStream out = sslsocket.getOutputStream(); // Write a test byte to get a reaction out.write(1); while (in.available() > 0) { System.out.print(in.read()); } System.out.println("Successfully connected"); } catch (Exception exception) { exception.printStackTrace(); } } } |
Step 2: Run on a command line to test
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java -cp . SSLPoke www.myhost 443 |
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java -Djavax.net.ssl.trustStore="C:\path\to\trusstore\certificates\myapp-trus.jks" -Djavax.net.ssl.trustStorePassword=changeit -Djavax.net.ssl.keyStore="C:\path\to\keystore\myapp-services.jks" -Djavax.net.ssl.keyStorePassword=changeit -Djavax.net.debug=ssl -cp . SSLPoke www.myhost 443 |
2. OpenSSL
If you have cygwin running on your windows or working on a unix box, the openssl utility can be used to connect to an SSL-enabled service, and print each stage described above:
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$ openssl s_client -connect mail.prefetch.net:443 -state -nbio 2>&1 | grep "^SSL" |
3. keytool to list all the certificates in the keystore
Check whether the keys are of a supported type, the required CA certificates are stored and that your application is using the correct one.
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keytool -list -v -keystore location_of_keystore |
Check the “SHA1” or “SHA2” token to see if it matches with the certificate that you downloaded from a browser.
4. Turn on SSL handshake by turning on debug option
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-Djavax.net.debug=ssl:handshake |
or
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-Djavax.net.debug=ssl |
5. InstalCert Java class to install the certificates into “jssecacerts”
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/* * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Sun Microsystems nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ import java.io.*; import java.net.URL; import java.security.*; import java.security.cert.*; import javax.net.ssl.*; public class InstallCert { public static void main(String[] args) throws Exception { String host; int port; char[] passphrase; if ((args.length == 1) || (args.length == 2)) { String[] c = args[0].split(":"); host = c[0]; port = (c.length == 1) ? 443 : Integer.parseInt(c[1]); String p = (args.length == 1) ? "changeit" : args[1]; passphrase = p.toCharArray(); } else { System.out.println("Usage: java InstallCert <host>[:port] [passphrase]"); return; } File file = new File("jssecacerts"); if (file.isFile() == false) { char SEP = File.separatorChar; File dir = new File(System.getProperty("java.home") + SEP + "lib" + SEP + "security"); file = new File(dir, "jssecacerts"); if (file.isFile() == false) { file = new File(dir, "cacerts"); } } System.out.println("Loading KeyStore " + file + "..."); InputStream in = new FileInputStream(file); KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType()); ks.load(in, passphrase); in.close(); SSLContext context = SSLContext.getInstance("TLS"); TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm()); tmf.init(ks); X509TrustManager defaultTrustManager = (X509TrustManager) tmf.getTrustManagers()[0]; SavingTrustManager tm = new SavingTrustManager(defaultTrustManager); context.init(null, new TrustManager[] { tm }, null); SSLSocketFactory factory = context.getSocketFactory(); System.out.println("Opening connection to " + host + ":" + port + "..."); SSLSocket socket = (SSLSocket) factory.createSocket(host, port); socket.setSoTimeout(10000); try { System.out.println("Starting SSL handshake..."); socket.startHandshake(); socket.close(); System.out.println(); System.out.println("No errors, certificate is already trusted"); } catch (SSLException e) { System.out.println(); e.printStackTrace(System.out); } X509Certificate[] chain = tm.chain; if (chain == null) { System.out.println("Could not obtain server certificate chain"); return; } BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); System.out.println(); System.out.println("Server sent " + chain.length + " certificate(s):"); System.out.println(); MessageDigest sha1 = MessageDigest.getInstance("SHA1"); MessageDigest md5 = MessageDigest.getInstance("MD5"); for (int i = 0; i < chain.length; i++) { X509Certificate cert = chain[i]; System.out.println(" " + (i + 1) + " Subject " + cert.getSubjectDN()); System.out.println(" Issuer " + cert.getIssuerDN()); sha1.update(cert.getEncoded()); System.out.println(" sha1 " + toHexString(sha1.digest())); md5.update(cert.getEncoded()); System.out.println(" md5 " + toHexString(md5.digest())); System.out.println(); } System.out.println("Enter certificate to add to trusted keystore or 'q' to quit: [1]"); String line = reader.readLine().trim(); int k; try { k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1; } catch (NumberFormatException e) { System.out.println("KeyStore not changed"); return; } X509Certificate cert = chain[k]; String alias = host + "-" + (k + 1); ks.setCertificateEntry(alias, cert); OutputStream out = new FileOutputStream("jssecacerts"); ks.store(out, passphrase); out.close(); System.out.println(); System.out.println(cert); System.out.println(); System.out.println("Added certificate to keystore 'jssecacerts' using alias '" + alias + "'"); } private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray(); private static String toHexString(byte[] bytes) { StringBuilder sb = new StringBuilder(bytes.length * 3); for (int b : bytes) { b &= 0xff; sb.append(HEXDIGITS[b >> 4]); sb.append(HEXDIGITS[b & 15]); sb.append(' '); } return sb.toString(); } private static class SavingTrustManager implements X509TrustManager { private final X509TrustManager tm; private X509Certificate[] chain; SavingTrustManager(X509TrustManager tm) { this.tm = tm; } public X509Certificate[] getAcceptedIssuers() { throw new UnsupportedOperationException(); } public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException { throw new UnsupportedOperationException(); } public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException { this.chain = chain; tm.checkServerTrusted(chain, authType); } } } |
