Message layer authentication

Defines the credential information and sends that information across the network so that a receiving server can interpret it.

When you send authentication information across the network using a token the transmission is considered message layer authentication because the data is sent with the message inside a service context.

A pure Java client uses basic authentication (GSSUP) as the authentication mechanism to establish client identity.

However, a servlet can use either basic authentication (GSSUP) or the authentication mechanism of the server (LTPA) to send security information in the message layer. Use LTPA by authenticating or by mapping the basic authentication credentials to the security mechanism of the server.

The security token that is contained in a token-based credential is authentication mechanism-specific. The way that the token is interpreted is only known by the authentication mechanism. Therefore, each authentication mechanism has an object ID (OID) representing it. The OID and the client token are sent to the server, so that the server knows which mechanism to use when reading and validating the token. The following list contains the OIDs for each mechanism:

BasicAuth (GSSUP): oid:2.23.130.1.1.1
LTPA: oid:1.3.18.0.2.30.2
SWAM: No OID because it is not forwardable

On the server, the authentication mechanisms can interpret the token and create a credential, or they can authenticate basic authentication data from the client, and create a credential. Either way, the created credential is the received credential that the authorization check uses to determine if the user has access to invoke the method. We can specify the authentication mechanism by using the following property on the client side:

• com.ibm.CORBA.authenticationTarget

Basic authentication is currently the only valid value. One can configure the server through the administrative console.

While this property tells you which authentication mechanism to use, you also need to specify whether you want to perform authentication over the message layer, that is get a BasicAuth or a token-based credential. To complete this task, specify the com.ibm.CSI.performClientAuthenticationRequired (True or False) and com.ibm.CSI.performClientAuthenticationSupported (True or False) properties. Indicating that client authentication is required implies that it must be done for every request. Indicating that the authentication mechanism is supported implies that it might be done, but is not required. For some servers, this option is appropriate if no resources are protected. In most cases, it is a best practice to indicate that this mechanism is supported so that client authentication is performed if both the client and server support it. Client authentication is not performed when communicating with certain servers that do not want security, yet the method requests still succeed.

 

Configuring

authentication retries

Situations occur where you want a prompt to display again if you entered your user ID and password incorrectly or you want a method to retry when a particular error occurs back at the client. If one can correct the error by information at the client side, the system automatically performs a retry without the client seeing the failure, if the system is configured appropriately.

Some of these errors include:

• Entering a user ID and password that are not valid

• Having an expired credential on the server

• Failing to find the stateful session on the server

By default, authentication retries are enabled and perform three retries before returning the error to the client. Use the com.ibm.CORBA.authenticationRetryEnabled property (True or False) to enable or disable authentication retries. Use the com.ibm.CORBA.authenticationRetryCount property to specify the number of retry attempts.

 

Immediate

validating of a basic authentication login

In WebSphere Application Server V6, a behavior is defined during request_login for a BasicAuth login. In releases prior to V5, a BasicAuth login takes the user ID and password entered through the loginSource method and creates a BasicAuth credential. If either the user ID or the password is not valid, the client program does not find out until the first method request is attempted. When the user ID or password is specified during a prompt or programmatic login, the user ID and password are authenticated by default with the security server, with a True or False returned as the result. If False, an org.omg.SecurityLevel2.LoginFailed exception is returned to the client indicating that the user ID and password are not valid. If True, then the BasicAuth credential is returned to the caller of the request_login. To disable this feature on the pure client, specify com.ibm.CORBA.validateBasicAuth=false. By default, this feature is set to True. On the server side, specify this property in the security dynamic properties.

 

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