Kayra Hopkins Loretta Macklem Proxy Protocols SOCKS 4, 4a, and 5 Advanced Software Engineering (CSE870) Instructor: Dr. B. Cheng Contact info: chengb at cse dot msu dot edu Kayra Hopkins Loretta Macklem
Outline Introduction Frameworks Demo Extra Credit Implementation
Introduction SOCKS - an Internet protocol that allows client-server applications to transparently use the services of a network.
SOCKS Protocols SOCKS 4 SOCKS 4a SOCKS 5 No authentication Simple connect and bind connections supported SOCKS 4a Domain resolution SOCKS 5 Authentication plus UDP connection supported
Frameworks Framework - a reusable design for a software system expressed as Set of abstract classes The way their instances collaborate for a specific type of software
Use of Frameworks for SOCKS SOCKS versions have a large amount of common functionality First step was to identify all major common functionality.
Whitebox Commonalities Differences (points of extension) Identify if client or server can access IP requested Creating a connection to a server Receiving messages Forwarding messages Sending reply messages Authentication Differences (points of extension) Parsing the request message Forming the reply message Creating new types of authentication
Whitebox, cont. Design Pattern Iterator Pattern Username/Password Login Domain Resolution Authentication
Whitebox Class Diagram
Magenta is Design Pattern, Green is where user implements functionality, Blue is abstract class
Greybox Changes Authentication is now an interface At the time only one protocol used authentication so we thought it would be the easiest to change for greybox
Red is interfaces, Magenta is Design Pattern, Green is where user implements functionality, Blue is abstract class
Blackbox All extension are done through interfaces
Red is interfaces, Magenta is Design Pattern, Green is where user implements functionality
State Diagram Connected Connection Denied
Demo
Problems We Encountered Figuring out how to get the information from the request messages without having the control loop be changed much Solution - have implementation of parsing the request message have a function which returns an array with all of the needed values to be passed to reply message implementation
What We Learned No comment on whether making a whitebox is easier than making a blackbox Able to identify where we have used frameworks previously without knowing it
Applying Our Framework to MISys Decided to place all patient records on a separate server, apart from the application MISys uses proxy to connect to other server and obtain patient information
Class Diagram MISys SOCKS Framework
Framework accesses Patient or Appointment Records Makes call to obtain Patient or Appt Records Connects to MISysMainUI class Connects to Iterator Class
MISys Demo
Questions?