Portlet authentication
For resources protected by the portal, IBM WebSphere Portal uses CORBA credentials and an encrypted LTPA cookie to authenticate users. However, for backend systems that require their own authentication, portlets need to provide some form of authentication to access these remote applications. In order to provide a single sign-on user experience, portlets must be able to store and retrieve user credentials for their particular associated application and use those credentials to log in on behalf of the user. WebSphere Portal supports the use of a credential vault where users and administrators can safely store credentials for authentication. Portlets written to extract the user's credentials from the vault can hide the login challenge from the user.
The credential vault provides exactly this functionality. Portlets can use it through the credential vault portlet service (CredentialVaultService).
- Credential vault organization
- Vault segments
- Vault slots
- Credential objects
- Credential vault usage scenarios
- Credential vault samples
- Change the credential vault encryption
Credential vault organization
The portal server's credential vault is organized as follows:- The portal administrator can partition the vault into several vault segments. Vault segments can be created and configured only by portal administrators.
- A vault segment contains one or more vault slots. Vault slots are the "drawers" where portlets store and retrieve a user's credentials. Each slot holds one credential.
- A vault slot is linked to a resource in a vault implementation.
- A vault implementation is the place where users credentials are actually stored. Examples of vault implementations include the default database vault or the Tivoli Access Manager lock box.
- The resource within the vault implementation corresponds to an application or backend system that requires its own authentication. Examples of resources include Lotus Notes, personnel records, or a bank account.
Vault segments
A vault segment is flagged to be either administrator-managed or user-managed. While portlets (on behalf of a portal user) can set and retrieve credentials in both types of segments, they are permitted to create vault slots only in user-managed vault segments. The following figure shows how administrator-managed vault segments can be distributed among different vault implementations. There is only one user-managed vault segment, and it resides in the default-customization vault provided by WebSphere Portal.
Vault slots
The credential vault provided by WebSphere Portal distinguishes between four different types of vault slots:- Vault Slots in administrator-managed vault segments:
- A system slot stores system credentials where the actual secret is shared among all users and portlets. It is a shared slot that belongs to an administrative segment. This slot type can be created through the Credential Vault administrative portlet, by adding a new slot in an a administrator-managed vault segment and mark it as shared.
- An administrative slot allows each user to store a secret for an administrator-defined resource
For example... Lotus Notes. It is an unshared slot that belongs to an administrative segment. This slot type can be created through the Credential Vault administrative portlet, by adding a new slot in an a administrator-managed vault segment and do not mark it as shared.
- Vault Slots in user-managed vault segments:
- A shared user slot stores user credentials that are shared among the user's portlets. It is a shared slot that belongs to the user segment. This slot type can be created through the Credential Vault portlet service by using the appropriate method and setting the argument as true for shared slot.
- A portlet private slot stores user credentials that are not shared among portlets. It is an unshared slot that belongs to the user segment. This slot type can be created through the Credential Vault portlet service by using the appropriate method and setting the argument as false for shared slot.
The following tables shows the constraints applicable for the available vault slot types:
| Vault Slot Type | Segment type | Shared | Creation through | Secret Sharing |
|---|---|---|---|---|
| System Slot | administrator-managed | true | Credential Vault administrative portlet | one secret per system - shared among all users and portlets |
| Administrative Slot | administrator-managed | false | Credential Vault administrative portlet | one secret per user - shared among all of user's portlets |
| Shared User Slot | user-managed | true | Credential Vault portlet service | one secret per user - shared among all of user's portlets |
| Portlet Private Slot | user-managed | false | Credential Vault portlet service | one secret per user and portlet entity - not shared among portlets |
Credential objects
The credential vault portlet service returns credentials in form of credential objects. The following are the base interface classes for all credential objects: Standard portlet API
com.ibm.portal.portlet.service.credentialvault.credentials.CredentialIBM Portlet API
com.ibm.wps.portletservice.credentialvault.credentials.CredentialWebSphere Portal differentiates between passive and active credential objects.
- Passive credential objects are containers for the credential's secret.
Portlets that use passive credentials need to extract the secret from the credential and do all the authentication communication with the backend itself.
Example: Passive credential object use (pseudo code)
Object userSecret = credential.getUserSecret(); < portlet connects to backend system authenticates using the user's secret > < portlet can use the connection to communicate with the backend application > < portlet takes care of logging at the backend >
- Active credential objects hide the credential's secret from the portlet; there is no way of extracting it out of the credential. In return, active credential objects offer business methods that take care of all the authentication.
// log into the backend system credential.login() // get an authenticated connection to work with URLConnection = credential.getAuthenticatedConnection(); // log out at the back end credential.logout();
Active credential objects allow portlets to trigger authentication to remote servers using standard mechanisms such as basic authentication, HTTP form-based authentication, or POP3 authentication, without obtaining the credential secrets. They can ask the portal to authenticate on their behalf and then use already authenticated connections. From a security point of view the portlets never access the credential secrets and thus there is no risk a portlet could violate any security rules like, for example, storing the secret on the portlet session. While there might not always be an appropriate active credential class available, it is the preferred type of credential object to use.
All credential types that are available within the portal are registered in a credential type registry. WebSphere Portal provides a small set of credential types, but additional credential objects can be registered in this registry.
The ActiveCredential and PassiveCredential interfaces inherit from the Credential base interface. The following topics describe the different types of active and passive credential objects provided by WebSphere Portal:
Passive Credential Objects:
SimplePassive
This credential object stores secrets in the form of serializable Java objects. As the vault service does currently not support binary large object (BLOB) secrets, this is intended for future use only.
UserPasswordPassive
Credential object that stores secrets in the form of userid/password pairs.
JaasSubjectPassive
Credential object that stores secrets in form of javax.security.auth.Subject objects. Again, this kind of secret cannot currently be stored by the vault service. It is used as a transient credential that is not persisted but taken from the user's session.
Credential object that stores secrets in the form of a byte array.
Active Credential Objects:
This credential stores secrets in binary form.
The following credentials store the user's secret as a userid/password pair.
HttpBasicAuth
This credential object stores userid/password secrets and supports HTTP Basic Authentication.
HttpFormBasedAuth
This credential object stores userid/password secrets and supports HTTP Form-Based Authentication.
JavaMail
A credential object that stores userid/password pairs and leverages the authentication functionality of the javax.mail API.
The following credentials store the user's secret as a JAAS Subject. These credentials are not persisted in the Credential Vault but created from the user's JAAS Subject associated with the current session.
LtpaToken or LtpaToken2
A credential object for authenticating with a backend system that is within the same WAS single sign-on domain as the portal.
LtpaToken2 is only available if attribute propagation is enabled.
Computer Associates eTrust SiteMinder Token
A credential object for authenticating with a backend system that is within the same eTrust SiteMinder single sign-on domain as the portal. This credential should be used when eTrust SiteMinder is used as an authentication proxy for the portal.
WebSealToken
A credential object for authenticating with a backend system that is within the same WebSEAL single sign-on domain as the portal. This credential should be used when a WebSEAL authentication proxy is used by the portal.
A credential object for authenticating with a back-end system that is within the same Openwave SSM single sign-on domain as the portal. This credential should be used when Openwave SSM is the authentication proxy for the portal authentication. The credential needs to be provided in form of the portal's
JAAS Subject containing a private credential that holds the user's SSMCredential.
Storing credential objects in the PortletSession
Credential objects do not implement java.io.Serializable - they cannot simply be stored in the PortletSession. This is for security reasons. Because the credential classes store the actual credential secret as one of their private attributes, the secret could be found by anyone who has access to the application server session database.
However, you can store a credential object in the PortletSession as long as you ensure sure that it is not serialized in a cluster setup. One way of doing this would be to define a credential container class that stores the actual credential object as a transient member. This container object can then be stored in the PortletSession without any problems you only have to make sure to check whether the credential object got lost during serialization and in this case retrieve it from the vault again.
import com.ibm.portal.portlet.service.credentialvault.credentials.Credential;
public class CredentialSessionContainer implements java.io.Serializable
{
private transient Credential credential = null;
public void setCredential(Credential cred) {this.credential = cred;}
public Credential getCredential() {return credential;}
public boolean hasCredential() {return credential != null;}
}
Credential vault usage scenarios
Portlets that need a credential to complete their service have two options:- Use an existing slot that has been defined by the portal administrator in an administrator-managed vault segment.
- Create a new slot in the user-managed vault segment.
The option you choose depends on how the portlet will be used.
Generally, the best solution hides the technical details of the credential vault from users. Additionally, Active Credentials of the type JaasSubjectCredential provide the portlet with the ability to access resources within the same single sign-on domain as the portal. The following are some example scenarios for the use of slots.
Intranet Lotus Notes mail portlet
A company has an intranet employee portal. Each portal user has a
Lotus Notes mail server account and a Lotus Notes mail portlet will be deployed and pre-configured on one of the employee's default portal pages.
Design solution:
The Notes mail portlet needs to store the user's Notes password.
As most users will actually use this portlet, the administrator needs to create a " Lotus Notes Credential Slot" for it through the Credential Vault administrative portlet. Using the portlet's configure mode, the administrator sets the vault slot ID for all portlet entries. The portlet allows users to set their personal Notes password in edit mode. The portlet can store each user's password in the credential vault.
If the company would use a Lotus Domino server within the same single sign-on domain as portal, it would also be possible to use an LTPAToken Credential based on the user's
JAAS Subject. This credential offers access to the domino server through an authenticated connection that reuses the user's LTPA token.
Stock of inventory portlet
A company's buying department runs a portal that integrates different legacy applications. One of these applications is a mainframe ordering application that directly connects to the systems of the suppliers. Several employees use the ordering portlet. However, the mainframe application is secured by a single system ID; it does not support several user accounts.
Design solution: The ordering portlet needs to access the ordering application under the system ID. The administrator configures the vault slot ID during portlet deployment. The portal administrator therefore creates a vault slot in an administrator-managed vault segment and marks it as a system credential. The administrator uses the Credential vault portlet to store the ordering system ID and password in this slot. The buying department's employees do not have to be concerned with credentials at all.
Internet Mail federating POP3 portlet
An Internet community portal offers, among other features, a mail-federating portlet that can be used by a portal user to collect mail from a number of POP3 mail accounts.
Design solution: The mail federating portlet is just another feature of the community portal and thus is likely to be used only by some of the portal users. Furthermore, it is not clear from the outset how many mail accounts a user wants to federate. Therefore, it does not make sense for the portal administrator to create a vault slot for this portlet.
Instead, the portlet provides users with a comfortable configuration in edit mode. Users can add as many POP3 mailboxes as necessary. The portlet creates a vault slot for each of the user's mailboxes in the user-managed vault segment.
Theoretically, a user could configure two instances of the portlet on a page, one for business accounts and one for private mail accounts. Therefore, and because it most likely doesn't make sense to share the user's mail credentials with other portlets, the portlet created vault slots are better marked as portlet private.
Credential vault samples
This section contains sample code for using the credential vault service.
Standard portlet example from Rational Application Developer
When you use the portlet wizard in Rational Application Developer to create portlets that use the credential vault portlet service, the wizard generates a SecretManager class for you that handles common tasks. The session bean generated by the wizard includes getters and setters for the secret type and vault slot name. The following examples show code that could be generated for you, depending on your selections, when you create a JSR 168 portlet project.
This code is only a demonstration of how use the credential vault. Any code generated must be further customized for your specific application requirements.
- Retrieve the credential vault portlet service.
- Set the credential.
- Get a slot for storing the user's credentials.
- The slot name is set as a portlet preference so that it can be changed by the administrator to any slots created using the portal administration interface.
- For a portlet private slot, this method creates a new slot if the slot name from the portlet preferences is null. The createNewSlot() method is another custom method of SecretManager that uses to createCredentialSlot() method of the credential vault service. This method can only create non-system slots and returns a CredentialSlotConfig object. The slotID of the new slot is stored in the portlet preferences and is used to update and retrieve the portlet private credentials.
- For a shared slot, this method searches for a shared resource name from accessible slots. If a shared slot is not available, it creates a new slot.
- Retrieving the credential
This code is placed in the init() method of the SecretManager and is called from the init() of the main portlet class.
See Accessing portlet services for general information about how portlet services are retrieved using JNDI.
public static void init(PortletConfig config) throws PortletException {
try {
if(vaultService == null ) {
Context ctx = new InitialContext();
PortletServiceHome cvsHome =
(PortletServiceHome)ctx.lookup("portletservice/com.ibm.portal.portlet.
service.credentialvault.CredentialVaultService");
if (cvsHome != null) {
vaultService = (CredentialVaultService)cvsHome.getPortletService
(CredentialVaultService.class);
}
}
} catch (Exception e) {
throw(new PortletException("Error on init()", e));
}
}
The portlet's processAction() method gets the USERID and PASSWORD parameters on the action request from the edit JSP.
If both parameters are not null, then these are used to set the credential.
if(request.getParameter(USER_SUBMIT) != null )
{
// Set userId/password text in the credential vault
PortletSessionBean sessionBean = getSessionBean(request);
if(sessionBean!=null )
{
String userID = request.getParameter(USERID);
String password = request.getParameter(PASSWORD);
// save only if both parameters are set
if(userID!=null && password!=null && !userID.trim().equals("") && !password.trim().equals(""))
{
try
{
SecretManager.setCredential(request,sessionBean,userID,password);
}
catch (Exception e)
{
//Exception Handling
}
}
}
}
The setCredential() method in the SecretManager class determines if the portlet can write to the slot and if the slot ID has content. If so, it uses the setCredentialSecretUserPassword() method of the credential vault service to set the credential to the slot.
public static boolean setCredential(PortletRequest portletRequest
PortletSessionBean sessionBean,
String userID,
String password) throws PortletException { try {
if(isWritable(sessionBean) )
{
String slotId = getSlotId(portletRequest,sessionBean,true); // create
slot if necessary
if(slotId != null ) {
vaultService.setCredentialSecretUserPassword(slotId,userID,password.
toCharArray(),portletRequest);
return true;
}
}
} catch(CredentialVaultException e) {
//Exception Handling
} return false;
}
The setCredential() method calls this method to either create a new slot or use an existing, accessible slot.
private static String getSlotId(PortletRequest portletRequest,
PortletSessionBean sessionBean,
boolean bCreate) throws PortletException {
String slotId = null;
String slotName = sessionBean.getVaultSlotName();
switch(sessionBean.getSecretType() ) {
case SECRET_PORTLET_PRIVATE_SLOT:
PortletPreferences prefs = portletRequest.getPreferences();
String prefsKey = ".slot."+portletRequest.getRemoteUser()+".
"+slotName;
slotId = prefs.getValue(prefsKey,null);
if(slotId==null && bCreate ) {
slotId = createNewSlot(portletRequest,slotName, true); //
create private slot
if(slotId != null ) {
try {
prefs.setValue(prefsKey,slotId);
prefs.store();
}
catch(Exception e ) {
throw(new PortletException("Error on PortletPreferences.
store()", e));
}
}
}
break;
case SECRET_SHARED_SLOT:
try {
Iterator it = vaultService.getAccessibleSlots(portletRequest);
while(it.hasNext() ) {
CredentialSlotConfig config = (CredentialSlotConfig)it.next() ;
//searches for shared resource name
if(config.getResourceName().startsWith(slotName ) ) {
slotId = config.getSlotId();
break;
}
}
if(slotId==null && bCreate )
slotId = createNewSlot(portletRequest,slotName,false);
// create shared slot
}
catch(CredentialVaultException e) {
// exception handling goes here
}
break;
default:
slotId = slotName;
break;
}
return slotId;
}
Both the doView() and doEdit method call getCredential() from the SecretManager. For the case of passive credentials, this portlet sets the USERID and PASSWORD returned from this method as attributes on the request.
StringBuffer userId = new StringBuffer(""); StringBuffer password = new StringBuffer(""); try
{
SecretManager.getCredential(request,sessionBean,userId, password);
} catch(Exception e )
{
getPortletContext().log("Exception on SecretManager.getCredential(): "+e.getMessage());
}
request.setAttribute(USERID,userId.toString()); request.setAttribute(PASSWORD,password.toString());
The getCredential() method of SecretManager handles UserPasswordPassiveCredential types. The type of credential is set as an Integer in the portlet preferences. The getCredential() method of the credential vault service is used to obtain the credentials stored in the slot.
public static void getCredential(PortletRequest portletRequest
PortletSessionBean sessionBean,
StringBuffer userid,
StringBuffer password) throws PortletException
{
try
{
String slotId = getSlotId(portletRequest,sessionBean,false);
if(slotId != null )
{
UserPasswordPassiveCredential credential =
(UserPasswordPassiveCredential)vaultService.getCredential
(slotId,CredentialTypes.USER_PASSWORD_PASSIVE,new
HashMap(),portletRequest);
if(credential != null)
{
userid.append(credential.getUserId());
password.append(String.valueOf(credential.getPassword()));
}
}
}
catch(CredentialVaultException e)
{
// exception handling goes here
}
}
IBM example that reads a credential from the vault
The following is an example of an IBM portlet that uses a userid/password credential to log into a Web application that is secured with an HTTP form-based login page. The example shows how the CredentialVaultService is used to read a credential from the vault and how to use this credential. It does not show how in the portlet's edit mode the portlet queries the user for his/her secret and stores it in the vault. This example is incomplete and should not be pasted into working code.
import org.apache.jetspeed.portlet.service.PortletServiceException; import com.ibm.portal.portlet.service.credentialvault.CredentialVaultService; import com.ibm.portal.portlet.service.credentialvault.CredentialSecretNotSetException; import com.ibm.portal.portlet.service.credentialvault.credentials.
HttpFormBasedAuthCredential;
...
public void doView (PortletRequest request, PortletResponse response)
throws PortletException, IOException
{
// get output stream and write out the results
PrintWriter writer = response.getWriter();
// get the CredentialVault PortletService
PortletContext context = this.getPortletConfig().getContext();
CredentialVaultService service =
(CredentialVaultService) context.getService(CredentialVaultService.class);
// retrieve slotId from persistent portlet data
String slotId = (String) request.getData().getAttribute("VaultTestSlotID");
if (slotId == null) {
writer.println("<h3>Credential not found. Please set it in the edit mode! </h3>");
return;
}
// bundle the credential config data mostly based on the backend application's login
form
HashMap config = new HashMap();
config.put(HttpFormBasedAuthCredential.KEY_USERID_ATTRIBUTE_NAME, "j_userid");
config.put(HttpFormBasedAuthCredential.KEY_PASSWORD_ATTRIBUTE_NAME, "j_password");
config.put(HttpFormBasedAuthCredential.KEY_LOGIN_URL, "EAI.yourco.com/myapp/
j_security_check");
config.put(HttpFormBasedAuthCredential.KEY_LOGOUT_URL,"EAI.yourco.com/myapp/
quit.jsp");
config.put(HttpFormBasedAuthCredential.KEY_USE_AUTH_COOKIES, Boolean.TRUE);
List formData= new ArrayList();
formData.add("action=Login");
// add the POST data that the form's login button will generate (name=value)
config.put(HttpFormBasedAuthCredential.KEY_FORM_DATA, formData);
// get the actual credential from the credential vault
HttpFormBasedAuthCredential credential;
try {
credential = (HttpFormBasedAuthCredential)
service.getCredential(slotId, "HttpFormBasedAuth", config, request);
} catch (PortletServiceException serviceExc) {
writer.println("<h3>Credential vault error, please contact your admin! </h3>");
return;
} catch (CredentialSecretNotSetException userExc) {
writer.println("<h3>Credential not set. Please set it in the edit mode! </h3>");
return;
}
try {
// use credential object to log in at the backend server
credential.login();
// get an authenticated connection to the backend server and send the actual request
connection = credential.getAuthenticatedConnection("EAI.yourco.com/request.jsp");
// Work with the connection: send an HTTP GET or POST and evaluate the response
[...] // your business code
// use credential object to log out at the backend server
credential.logout();
} catch (IOException exc) {
writer.println("<h3>Single-sign-on error, login at backend failed! </h3>");
return;
}
// get output stream and write out the results
PrintWriter writer = response.getWriter();
}
Change the credential vault encryption
WebSphere Portal supports plugging in different vault adapters for the storage and retrieval of credentials. The default vault adapter that ships with WebSphere Portal stores user credentials in the portal configuration database. By default, the passwords are only obfuscated, but not encrypted.
See the How to change the encryption of the credential vault in WebSphere Portal technote for information on how to extend the default vault adapter to use your own encryption code for encrypting and decrypting the passwords.