Example: Developing a custom key manager for custom SSL key selection

The following example is of a sample custom key manager. This simple key manager returns the configured alias if it is set using the alias properties com.ibm.ssl.keyStoreClientAlias or com.ibm.ssl.keyStoreServerAlias, depending on which side of the connection the key manager is used. The key manager defers to the JSSE default IbmX509 key manager to select an alias if these properties are not set.

After you build and package a custom key manager, we can configure it from either the ssl.client.props file for a pure client or by using the SSLConfiguration KeyManager link in the admin console. See Key manager control of X.509 certificate identities for more information about key managers. Because only one key manager can be configured at a time for any given SSL configuration, the certificate selections on the server side might not work as they would when the default IbmX509 key manager is specified. When a custom key manager is configured, it is up to the owner of that key manager to verify the selection of the alias from the SSL configuration supplied is set properly when chooseClientAlias or chooseServerAlias are called. Look for the com.ibm.ssl.keyStoreClientAlias and com.ibm.ssl.keyStoreServerAlias SSL properties.

This example should only be used as a sample, and is not supported.

package com.ibm.test;
 import java.security.cert.X509Certificate;
 import com.ibm.wsspi.ssl.KeyManagerExtendedInfo;
 public final class CustomKeyManager 
  implements javax.net.ssl.X509KeyManager, com.ibm.wsspi.ssl.KeyManagerExtendedInfo
{
    private java.util.Properties props = null;
    private java.security.KeyStore ks = null;
    private javax.net.ssl.X509KeyManager km = null;
    private java.util.Properties sslConfig = null;
    private String clientAlias = null;
    private String serverAlias = null;
    private int clientslotnum = 0;
    private int serverslotnum = 0;

    public CustomKeyManager()
    {
    }

    /**
     * Method called by WAS runtime to set the custom
     * properties.
     * 
     * @param java.util.Properties - custom props
     */
    public void setCustomProperties(java.util.Properties customProps)
    {
        props = customProps;
    }

    private java.util.Properties getCustomProperties()
    {
        return props;
    }

    /**
     * Method called by WAS runtime to set the SSL
     * configuration properties being used for this connection.
     * 
     * @param java.util.Properties - contains a property for the SSL configuration.
     */
    public void setSSLConfig(java.util.Properties config)
    {
        sslConfig = config;                                   
    }

    private java.util.Properties getSSLConfig()
    {
        return sslConfig;
    }

    /**
     * Method called by WAS runtime to set the default
     * X509KeyManager created by the IbmX509 KeyManagerFactory using the KeyStore
     * information present in this SSL configuration.  This allows some delegation
     * to the default IbmX509 KeyManager to occur.
     * 
     * @param javax.net.ssl.KeyManager defaultX509KeyManager - default key manager for IbmX509
     */
    public void setDefaultX509KeyManager(javax.net.ssl.X509KeyManager defaultX509KeyManager)
    {
        km = defaultX509KeyManager;
    }

    public javax.net.ssl.X509KeyManager getDefaultX509KeyManager()
    {
        return km;
    }

    /**
     * Method called by WAS runtime to set the SSL
     * KeyStore used for this connection.
     * 
     * @param java.security.KeyStore - the KeyStore currently configured
     */
    public void setKeyStore(java.security.KeyStore keyStore)
    {
        ks = keyStore;
    }

    public java.security.KeyStore getKeyStore()
    {
        return ks;
    }

 /**
     * Method called by custom code to set the server alias.
     * 
     * @param String - the server alias to use
     */
    public void setKeyStoreServerAlias(String alias)
    {
        serverAlias = alias;
    }

    private String getKeyStoreServerAlias()
    {
        return serverAlias;
    }

    /**
     * Method called by custom code to set the client alias.
     * 
     * @param String - the client alias to use
     */
    public void setKeyStoreClientAlias(String alias)
    {
        clientAlias = alias;
    }
    
    private String getKeyStoreClientAlias()
    {
        return clientAlias;
    }

    /**
     * Method called by custom code to set the client alias and slot (if necessary).
     * 
     * @param String - the client alias to use
     * @param int - the slot to use (for hardware)
     */
    public void setClientAlias(String alias, int slotnum) throws Exception
    {
        if ( !ks.containsAlias(alias))
        {
            throw new IllegalArgumentException ( "Client alias " + alias + " 
            not found in keystore." );
        }
        this.clientAlias = alias;
        this.clientslotnum = slotnum;
    }

    /**
     * Method called by custom code to set the server alias and slot (if necessary).
     * 
     * @param String - the server alias to use
     * @param int - the slot to use (for hardware)
     */
    public void setServerAlias(String alias, int slotnum) throws Exception
    {
        if ( ! ks.containsAlias(alias))
        {
            throw new IllegalArgumentException ( "Server alias " + alias + " 
            not found in keystore." );
        }
        this.serverAlias = alias;
        this.serverslotnum = slotnum;
    }


    /**
     * Method called by JSSE runtime to when an alias is needed for a client
     * connection where a client certificate is required.
     * 
     * @param String keyType
     * @param Principal[] issuers
     * @param java.net.Socket socket (not always present)
     */
    public String chooseClientAlias(String[] keyType, java.security.Principal[]
    issuers, java.net.Socket socket)
    {
        if (clientAlias != null && !clientAlias.equals(""))
        {
            String[] list = km.getClientAliases(keyType[0], issuers);
            String aliases = "";

            if (list != null)
            {
                boolean found=false;
                for (int i=0; i<list.length; i++)
                {
                    aliases += list[i] + " ";
                    if (clientAlias.equalsIgnoreCase(list[i]))
                        found=true;
                }

                if (found)
                {
                    return clientAlias;
                }

            }
        }
        
        
// client alias not found, let the default key manager choose.
        String[] keyArray = new String [] {keyType[0]};
        String alias = km.chooseClientAlias(keyArray, issuers, null);
        return alias.toLowerCase();
    }

    /**
     * Method called by JSSE runtime to when an alias is needed for a server
     * connection to provide the server identity.
     * 
     * @param String[] keyType
     * @param Principal[] issuers
     * @param java.net.Socket socket (not always present)
     */
    public String chooseServerAlias(String keyType, java.security.Principal[] 
    issuers, java.net.Socket socket)
    {
        if (serverAlias != null && !serverAlias.equals(""))
        {
            
// get the list of aliases in the keystore from the default key manager
            String[] list = km.getServerAliases(keyType, issuers);
            String aliases = "";

            if (list != null)
            {
                boolean found=false;
                for (int i=0; i<list.length; i++)
                {
                    aliases += list[i] + " ";
                    if (serverAlias.equalsIgnoreCase(list[i]))
                        found = true;
                }

                if (found)
                {
                    return serverAlias;
                }
            }
        }

        
// specified alias not found, let the default key manager choose.
        String alias = km.chooseServerAlias(keyType, issuers, null);
        return alias.toLowerCase();
    }

    public String[] getClientAliases(String keyType, java.security.Principal[] issuers)
    {
        return km.getClientAliases(keyType, issuers);
    }

    public String[] getServerAliases(String keyType, java.security.Principal[] issuers)
    {
        return km.getServerAliases(keyType, issuers);
    }

    public java.security.PrivateKey getPrivateKey(String s)
    {
        return km.getPrivateKey(s);
    }

    public java.security.cert.X509Certificate[] getCertificateChain(String s)
    {
        return km.getCertificateChain(s);
    }

    public javax.net.ssl.X509KeyManager getX509KeyManager()
    {
        return km;
    }

}

---

Related concepts

Key manager control of X.509 certificate identities

 

Related tasks

Create a custom key manager for SSL