Proxy%20Protocols%20SOCKS%204,%204a,%20and%205%20Advanced%20Software%20Engineering%20(CSE870)%20Instructor:%20Dr.%20B.%20Cheng%20Contact%20info:%20chengb%20at%20cse%20dot%20msu%20dot%20edu

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Proxy ProtocolsSOCKS 4, 4a, and 5Advanced
Software Engineering (CSE870)Instructor Dr. B.
ChengContact info chengb at cse dot msu dot edu

• Kayra Hopkins
• Loretta Macklem

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Outline

• Introduction
• Frameworks
• Demo
• Extra Credit Implementation
• Demo

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Introduction

• SOCKS - an Internet protocol that allows
  client-server applications to transparently use
  the services of a network.

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SOCKS Protocols

• SOCKS 4
• No authentication
• Simple connect and bind connections supported
• SOCKS 4a
• Domain resolution
• SOCKS 5
• Authentication plus UDP connection supported

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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

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Use of Frameworks for SOCKS

• SOCKS versions have a large amount of common
  functionality
• First step was to identify all major common
  functionality.

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Whitebox

• Commonalities
• 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

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Whitebox, cont.

• Design Pattern
• Iterator Pattern
• Username/Password Login
• Domain Resolution
• Authentication

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Whitebox Class Diagram
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Magenta is Design Pattern, Green is where user
implements functionality, Blue is abstract class
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(No Transcript)
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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

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Red is interfaces, Magenta is Design Pattern,
Green is where user implements functionality,
Blue is abstract class
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Blackbox

• All extension are done through interfaces

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Red is interfaces, Magenta is Design Pattern,
Green is where user implements functionality
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State Diagram
Connected
Connection Denied
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Demo
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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

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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

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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

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Class Diagram
 
MISys
SOCKS Framework
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Framework accesses Patient or Appointment Records
Makes call to obtain Patient or Appt Records
Connects to MISysMainUI class
Connects to Iterator Class
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MISys Demo
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Questions?