keyboard-interactive is an SSH authentication mechanism that allows generic challenge-response type authentication to be performed. This can vary from a single prompt for the users' password to multiple rounds of challenges.
To support this type of authentication in Maverick Synergy you will need to provide a KeyboardInteractiveCallback implementation. Let's look at how we would set this up:
SshClient ssh = new SshClient("localhost", 22, "lee");
ssh.authenticate(new KeyboardInteractiveAuthenticator(new KeyboardInteractiveCallback() {
public void init(SshConnection connection) {
}
public void showPrompts(String name, String instruction, KeyboardInteractivePrompt[] prompts,
KeyboardInteractivePromptCompletor completor) {
}
});
As usual, you will see we are passing an Authenticator object to the SshClient to perform authentication. We have created an empty implementation of KeyboardInteractiveCallback. The init method is called before authentication starts, its there for you to use for any initialization that you need to perform, in most cases, you can leave this empty. If you want, you can store the SshConnection to maintain any state with its property methods. Alternatively, you could extend AbstractKeyboardInteractiveCallback which implements init with a method that simply stores the SshConnection to a protected "connection" variable.
When authentication starts, you should expect to receive one or more calls to the showPrompts method. You are required here to show the prompts provided to you to the user and receive a response. Below we show you how to do this using the console, by simply prompting the user through System.out and receiving input through System.in.
try {
System.out.println(instruction);
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
for(KeyboardInteractivePrompt prompt : prompts) {
System.out.print(prompt.getPrompt());
prompt.setResponse(reader.readLine());
}
completor.complete();
} catch (IOException e) {
completor.cancel();
}
In this code, we printed out the instruction field provided by the server, then iterate over the prompts, showing a prompt, and receiving the response back, the response from the user must be set on the KeyboardInteractivePrompt object using the setResponse method.
When you have completed all these, its important that you call the complete method on the KeyboardInteractivePromptCompletor object. This will submit the responses back to the server, without this your authentication will hang. If for any reason the user wants to cancel the authentication, call the cancel method on the KeyboardInteractivePromptCompletor object.
