Configure your web application and server for client certificate authentication

We can configure your web application in Liberty using SSL client authentication.

This topic assumes that we have already created the SSL certificates, for example as described in Create SSL certificates from the command line.

Client certificate authentication occurs if the server-side requests that the client-side send a certificate. A WebSphere server can be configured for client certificate authentication on the SSL configuration. To do this, we add the transportSecurity-1.0 Liberty feature to the server.xml file, along with code that tells the server the keystore information for authentication.

For details of which aspects of SSL are supported, see Liberty features.

1. Ensure that the deployment descriptor for your web application specifies client certificate authentication as the authentication method to use. Check that the deployment descriptor includes the following element:

   <auth-method>CLIENT-CERT</auth-method>

   Note: We can use a tool such as Rational Application Developer to create the deployment descriptor.

2. Optional: Generate an SSL certificate using the command line.

   See securityUtility command.

3. Configure the server to enable SSL client authentication by adding the following lines to the server.xml file:

      <featureManager>
           <feature>transportSecurity-1.0</feature>
      <featureManager>
   
      <ssl id="defaultSSLConfig" keyStoreRef="defaultKeyStore"
           trustStoreRef="defaultTrustStore" clientAuthenticationSupported="true" />
      <keyStore id="defaultKeyStore" location="key.jks" type="JKS" password="defaultPWD" />
      <keyStore id="defaultTrustStore" location="trust.jks" type="JKS" password="defaultPWD" />

   • If we specify clientAuthentication="true", the server requests that a client sends a certificate. However, if the client does not have a certificate, or the certificate is not trusted by the server, the handshake does not succeed.

   • If we specify clientAuthenticationSupported="true", the server requests that a client sends a certificate. However, if the client does not have a certificate, or the certificate is not trusted by the server, the handshake might still succeed.

   • If we do not specify either clientAuthentication or clientAuthenticationSupported, or we specify clientAuthentication="false" or clientAuthenticationSupported="false", the server does not request that a client send a certificate during the handshake.

4. Add a client certificate to your browser.

   See the documentation of the browser for adding client certificates.

5. Make sure the server trusts any client certificates used.
6. Make sure any client certificates used for client authentication are mapped to a user identity in your registry.

   • For the basic registry, the user identity is the common name (CN) from the distinguished name (DN) of the certificate.

   • For a Lightweight Directory Access Protocol (LDAP) registry, the DN from the client certificate must be in the LDAP registry.

7. To use basic authentication, user ID and password only, if client certificate authentication does not succeed, add the following line to the server.xml file.

   <webAppSecurity allowFailOverToBasicAuth="true" />

   Note: If we specify allowFailOverToBasicAuth="false" or do not specify allowFailOvertoBasicAuth, and the client certificate authentication does not succeed, the request generates a 403 Authentication error message, and the client is not prompted for basic authentication.