public Class SecurityCallback

Implements javax.security.auth.callback.CallbackHandler.handle.

Doc from javax.security.auth.callback.CallbackHandler.handle.

Retrieve or display the information requested in the provided Callbacks.

The handle method implementation checks the instance(s) of the Callback object(s) passed in to retrieve or display the requested information. The following example is provided to help demonstrate what an handle method implementation might look like. This example code is for guidance only. Many details, including proper error handling, are left out for simplicity.

public void handle(Callback[] callbacks)
throws IOException, UnsupportedCallbackException {

  for (int i = 0; i < callbacks.length; i++) {
     if (callbacks[i] instanceof TextOutputCallback) {

         // display the message according to the specified type
         TextOutputCallback toc = (TextOutputCallback)callbacks[i];
         switch (toc.getMessageType()) {
         case TextOutputCallback.INFORMATION:
             System.out.println(toc.getMessage());
             break;
         case TextOutputCallback.ERROR:
             System.out.println("ERROR: " + toc.getMessage());
             break;
         case TextOutputCallback.WARNING:
             System.out.println("WARNING: " + toc.getMessage());
             break;
         default:
             throw new IOException("Unsupported message type: " +
                                 toc.getMessageType());
         }

     } else if (callbacks[i] instanceof NameCallback) {

         // prompt the user for a username
         NameCallback nc = (NameCallback)callbacks[i];

         // ignore the provided defaultName
         System.err.print(nc.getPrompt());
         System.err.flush();
         nc.setName((new BufferedReader
                 (new InputStreamReader(System.in))).readLine());

     } else if (callbacks[i] instanceof PasswordCallback) {

         // prompt the user for sensitive information
         PasswordCallback pc = (PasswordCallback)callbacks[i];
         System.err.print(pc.getPrompt());
         System.err.flush();
         pc.setPassword(readPassword(System.in));

     } else {
         throw new UnsupportedCallbackException
                 (callbacks[i], "Unrecognized Callback");
     }
  }
}

// Reads user password from given input stream.
private char[] readPassword(InputStream in) throws IOException {
   // insert code to read a user password from the input stream
}

Parameters

callbacks:Callback[]

an array of Callback objects provided by an underlying security service which contains the information requested to be retrieved or displayed.

Annotations

@Override

Exceptions

IOException:

if an input or output error occurs.

UnsupportedCallbackException:

if the implementation of this method does not support one or more of the Callbacks specified in the callbacks parameter.

Initializes this SecurityCallback for the given session.

Parameters

session:SessionContext

SessionContext of the keystore access

Returns:int

the number of PIN prompts to try to log-in to the token

Tells this SecurityCallback that an attempt to load something from the key store has been made.

Parameters

error:Exception

an Exception that may have occurred, or null on success

Returns:boolean

whether to try once more

Exceptions

IOException:

on errors

GeneralSecurityException:

on errors