RegisterServer

java.lang.Object
- vbsServer.RegisterServer

All Implemented Interfaces:

java.lang.Runnable
```
public class RegisterServer
extends java.lang.Object
implements java.lang.Runnable
```
The class RegisterServer is responsible for registering VBS clients.
The server listens on the port given in the constructor. When a client requests to be registered it must transfer the REGISTER_KEY, otherwise registration is ignored. If the registration is accepted a clientId is generated and transferred to the client.
Client having already an identifier does not need to register, so instead of REGISTER_KEY the identifier is transferred. If the identifier seems to be OK (the format is valid), then the client is treated as authenticated. The current big problem is that there is no database where the client identifier are stored and compared during the validation process, so everyone can submit any good-looking identifier and be considered as authenticated even without ever sending the REGISTER_KEY! This can be fixed by storing the assigned identifier in the Clients database table and then comparing if such client really exists. For now the Clients table is filled when a FDB file is transferred from the client to the server - the client identifier is copied from the FDB file.

It is intended to run in its own thread.

Author:

Jacob Honoré Broberg, Kartheepan Balachandran (kba@es.aau.dk), Tomasz Bujlow (tbu@es.aau.dk)

Field Summary

Fields
Modifier and Type	Field and Description
`static java.lang.String`	`CLIENT_VALIDATED_MESSAGE` Message send to the client when the client is successfully validated.
`private static org.apache.log4j.Logger`	`log` Used to log different events.
`private java.net.ServerSocket`	`myServerSocket` Socket on which the registration server listens for connection from clients.
`private java.net.Socket`	`mySocket` Socket used to transfer data to the client.
`static java.lang.String`	`REGISTER_KEY` Shared key used for registration of the client.
`private java.lang.Thread`	`registerServerThread` Thread used by the class.
`private boolean`	`runFlag` The thread will stop when this flag is `false`.

Constructor Summary

Constructors
Constructor and Description

RegisterServer(int port)
Constructs the object.

Constructors
Constructor and Description
`RegisterServer(int port)` Constructs the object.

Method Summary

Methods
Modifier and Type	Method and Description
`private boolean`	`authenticateNewRegistrer(java.lang.String key)` Checks if the obtained string equals to the registration key.
`private java.lang.String`	`getInputFromClient()` Gets an input from the client.
`boolean`	`isAlive()` Checks if the `RegisterServer` is running.
`private boolean`	`isGoodLookingClient(java.lang.String clientId)` Checks if the provided client identifier looks good.
`private void`	`registerClient()` Registers the client.
`void`	`run()` Runs the thread.
`private void`	`sendValidation()` Send an authorization message to the client.
`void`	`start()` Starts the thread.
`void`	`stop()` Stops the thread.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - log
```
private static org.apache.log4j.Logger log
```
    Used to log different events.
  - registerServerThread
```
private java.lang.Thread registerServerThread
```
    Thread used by the class.
  - REGISTER_KEY
```
public static final java.lang.String REGISTER_KEY
```
    Shared key used for registration of the client.
    
    See Also:
    Constant Field Values
  - CLIENT_VALIDATED_MESSAGE
```
public static final java.lang.String CLIENT_VALIDATED_MESSAGE
```
    Message send to the client when the client is successfully validated.
    
    See Also:
    Constant Field Values
  - myServerSocket
```
private java.net.ServerSocket myServerSocket
```
    Socket on which the registration server listens for connection from clients.
  - mySocket
```
private java.net.Socket mySocket
```
    Socket used to transfer data to the client.
  - runFlag
```
private boolean runFlag
```
    The thread will stop when this flag is false.
- Constructor Detail
  - RegisterServer
```
public RegisterServer(int port)
               throws java.io.IOException
```
    Constructs the object.
    
    Parameters:
    port - the port which the server listen on
    
    Throws:
    
    java.io.IOException - if the server cannot bind to the port
- Method Detail
  - start
```
public void start()
```
    Starts the thread.
  - stop
```
public void stop()
```
    Stops the thread.
  - isAlive
```
public boolean isAlive()
```
    Checks if the RegisterServer is running.
    
    Returns:
    true if the thread is fully started and operational, false otherwise
  - run
```
public void run()
```
    Runs the thread. It listens on a specified server socket and opens new socket for each client which tries to connect. At first the input from the client is obtained. There are 3 possibilities:
    - the input obtained from the client is the registration key. It means that the client needs to be register. A new client identifier is generated and sent back to the client - the input obtained from the client is something looking like a valid client identifier. In this case a message telling that the client is authenticated is sent to the client - the input obtained from the client is something looking like something else. In this case a message telling that the client is denied is sent to the client
    
    Specified by:
    
    run in interface java.lang.Runnable
  - getInputFromClient
```
private java.lang.String getInputFromClient()
                                     throws java.io.IOException
```
    Gets an input from the client.
    
    Returns:
    input from the client
    
    Throws:
    
    java.io.IOException - when a communication problem occurs
  - authenticateNewRegistrer
```
private boolean authenticateNewRegistrer(java.lang.String key)
                                  throws java.io.IOException
```
    Checks if the obtained string equals to the registration key.
    
    Parameters:
    key - the string obtained from the client
    
    Returns:
    true if the string matches the registration key, false otherwise
    
    Throws:
    
    java.io.IOException - if a communication problem occurs
  - registerClient
```
private void registerClient()
                     throws java.io.IOException
```
    Registers the client. Currently only create a new client identifier and sends it to the client.
    
    Throws:
    
    java.io.IOException - when a communication problem occurs
  - isGoodLookingClient
```
private boolean isGoodLookingClient(java.lang.String clientId)
```
    Checks if the provided client identifier looks good.
    
    Parameters:
    clientId - the client identifier
    
    Returns:
    true if the client identifier looks as valid, false otherwise
  - sendValidation
```
private void sendValidation()
                     throws java.io.IOException
```
    Send an authorization message to the client.
    
    Throws:
    
    java.io.IOException - if a communication problem occurs

Class RegisterServer

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

log

registerServerThread

REGISTER_KEY

CLIENT_VALIDATED_MESSAGE

myServerSocket

mySocket

runFlag

Constructor Detail

RegisterServer

Method Detail

start

stop

isAlive

run

getInputFromClient

authenticateNewRegistrer

registerClient

isGoodLookingClient

sendValidation