CSC424-E: Communications and Security
formerly CSC524, also EEN534

News and Announcements for CSC424 Communications and Security.

Apr 12:

Project 5 posted. Due April 24.

Feb 14:

Quiz 6 posted. Due April 8.

Feb 14:

Quiz 5 due April 1.

Feb 14:

Project 4 due date extended to April 3.

Feb 14:

Project 3 posted. Part A due March 6.

Feb 14:

Project 1 grades pushed to svn as grades.txt.

Feb 4:

Quiz 3 posted. Due Monday, Mar 2.

Feb 4:

Project 2 posted. Due Friday, Feb 20.

Jan 24:

Quiz 2 posted, with additional reading assigned. Due Fri, Feb 6.

Jan 21:

Project 1 posted. Due Wednesday, Feb 4.

Jan 19:

TA hours added to syllabus.

Jan 16:

Quiz 1 posted. Due Fri, Jan 23.

Jan 12:

Important dates:

• Jan 19, Holiday.
• Mar 7–15, Spring Recess
• Apr 24, Classes end

Jan 12:

Semester begins. Welcome!

• Follow the twitter feed.
• Like us on Facebook!

Syllabus for CSC424 Communications and Security.

This is a course in the standard communication protocols of computers, and the security concerns consequent to those protocols. The course is also an opportunity to learn systems coding, including the demanding requirements of C coding, and of reading and implementing to specifications.

• Readings:
  • The assigned textbook is Computer Networks, Fifth Edition by Tenenbaum and Wetherall.
  • Recommended reading I: The Victorian Internet by Standage.
  • Recommended reading II: An Introduction to Information Theory by John Pierce.
• New Media:
  • The class Twitter is http://twitter.com/csc524. Please follow it.
  • The class blog is http://blog.cs.miami.edu/burt/category/csc524/.
• Work:
  • Quizzes: Generally one per week. Out on Monday after class, due the next Wednesday by the end of class.
  • Projects: A series projects, assigned from a Monday to the second following Monday. However, this might vary according to pace and vacation schedule.
  • Project grading: Projects are generally scored on a 0 to 5 scale, with 5 being reserved for excellent projects. Grade depends on completeness, correctness, and presentation. Use of Subversion, Makefiles and file and folder names as requested are a must.
  • Lateness: Three days grace automatic on projects. Over that, one point off and an additional one point for each week late, up to three points. No lateness for quizzes.
  • All work to be done by the last day of class.
  • Class grading: After normalizations, 60% projects, 40% quizzes.
• Computers:
  • We will be working in various modes. I recommend strongly that you have your own computer to work on. We will install Virtual Box and work on virtual machines hosted by Virtual Box.
  • If you do not have a computer of sufficient power to work comfortably with Virtual Box, please we will discuss options.
  • We will make extensive use of subversion, a source code control system. You will turn in your assignments using subversion, and if you use subversion, I and the TA can help you by examining and correcting your code, at any time and from any location, when we are on-line.
• Contact:
  • The TA is Mohammad Laskar, nasir_at_cs.miami.edu. Office hours in UB 426, Thu 10:00-1:00 and Sun 11:00-2:00.
  • My Office hours: by appointment, at the moment.
  • Please email or chat, and we can work through subversion, if you project is committed and your Makefile is current.
• Writing credit: optionally the student may elect for wiring credit.
  • The requirement for W is three essays each of at least 1500 words
  • Topics related to computer communications, or cyberspace, at least one non-fiction.
  • First paper must be submitted by mid-term
  • Submit papers in a standard format by subervsion. Place them in a subdirectory writing-credit.
• Thanks to Amazon for a grant under their AWS for Education program, to explore cloud computing, and integrate cloud computing concepts into the course.

Class notes for CSC424 Communications and Security.

L0

• Introduction
  • Tools of the trade and network etiquette.
  • The OSI ISO model (image)
  • Discussion: Why layers? Why not layers?
  • Peer-to-peer responsibilities vs. SAP (service access points)
  • Encapsulation, headers and payload, demultiplexing (unpacking) (image)
  • Implementation and standards, for the Internet/WAN (image) and for the LAN (image)
• Basic concepts
  • Packet versus connection.
  • Broadcast versus routed.
  • Common and point-to-point mediums.
  • LAN versus WAN, and an internet.
  • Error and signals, signal coding.
• Technologies and techniques useful now
  • ping
  • traceroute
  • dig
  • arp
  • netstat

L1 and L2

• Crash course in information theory
  • The Shannon-Hartley Theorem (class blog)
  • Error: repetition codes, Hamming codes (class blog) (pdf, theory)
• Example Datalink layer - Ethernet
  • Carrier Sense Multiple Access / Collision Detect (exponential backoff)
  • Data signaling
    • 10Base-5: manchester encoded half-duplex 10Mbs
    • 10Base-T: Manchester Encoding full duplex over 4-pair unshielded twisted pair.
    • 100Base-TX:, MLT-3 and 4B5B line encoding.
    • 1000Base-T: 8B10B symbol encoding with PAM-5 line encoding, over 4 pairs simultaneously (256 symbols), with Trellis Forward Error Correction
    • 1000Base-SX: optical short distance, -LX long distance optical
  • Ethernet frames
    • Preamble and SFD
    • Ether Type 0x0600 and up, ex 0x0800 IP and 802.1Q tag 0x8100
    • Length (0x5ff and down) and the SNAP
    • Frame Check Sequence
  • MAC addresses
  • Broadcast, and multicast; the broadcast domain
• Example Datalink layer - WiFi
  • Class blog about WiFi.
  • Javvin documentation
  • Presentation notes:
    • BSS and infrastructure
    • Associations
    • Protocol: RTS, CTS, NAV and positive acknowledgment
    • Frame structure, relay addressing
    • Routing, bridging, and switching
    • Other: the beacon, and power-down buffering
  • The breaking of WEP
• Other Datalink layers
  • USB
  • Bluetooth
  • RS-232
  • Apple Desktop Bus
• Switches, bridges, and hubs
  • bridge transparency
  • Learning bridges
  • Bridge Spanning Tree Protocol (IEEE 802.1D)

L3

• Overview of networking
  • The network layer glues together data link layer hops.
  • L2 frame contains an IP packet with an IP header
  • The IP address gives the network name for the endpoint, and contains routing information in the prefix.
  • The IP packet can contain an UDP packet that starts with an UDP header
  • The ports are Transport Layer constructs, that route within the network endpoint (a.k.a. IP address)
• What's in a name
  • The MAC address is "just a name", and it pretty useless "far away" from the destination.
  • Names, such as www.miami.edu, are non-entities in TCP-UDP/IP. Only numbers count.
  • The role of DNS to turn names into numbers, before the networking game starts.
• Routing
  • Autonomous systems (AS), interior and exterior routing
  • Local delivery vs. routing; known route vs. default route
  • Distance vector Notes
  • counting to infinity; split horizon and poison reverse
  • Link State Protocols
• Enabling technologies
  • Time To Live
  • IP Fragmentation
• Networking strategies
  • Private local addresses
  • NAT and PAT (various flavors)
  • Firewalls
  • VPN's and tunnels (PPPoE)

L4

• UDP and TCP in the protocol layers
• Port numbers
  • Well Known Ports (a.k.a. Reserved),
  • Registered ports
  • Ephemeral ports (a.k.a. dynamic)
• Notes on TCP
• TCP Trace using tcpdump

L5 and Applications

• BSD Socket interface: Beej's Guide to Network Programming
• Domain Name Service (DNS). See RFC 1034 and RFC 1035.
• Dynamic Host Configuration Protocol (DHCP) RFC 2131
• Trivial File Transfer Protocol (TFTP)
• Simple Mail Transfer Protocol (SNMP)
• Post Office Protocol (POP)
• Internet Mail Access Protocol (IMAP)

Security and Cryptography

• Authentication
• Breaking SAML
• Proxy walk through
• Public Key Infrastructure and digital signatures
• Zero Knowledge authentication protocol

Quizzes for CSC424 Communications and Security.

See my subversion tutorial for getting a start with Subversion.

• Read chapter 1 of the class text and answer problems 1 through 6 and problem 10.
  Due Friday, Jan 23, by subversion as the file quiz1.txt in the folder [my_repo]/quiz/.
  Note: see [class_repo]]/quiz/quiz1.txt for the template.
• Read chapter 3 of the class text and answer the chapter 3 problems: 1 through 5, 11, 12, 13, 15, 16 and 17. Due: Friday, Feb 6.
• Read sections 4.1 through 4.4, and section 4.8 of the class text. There are no problems to answer. Read the sections by Friday, Feb 6.
• Read sections 4.8 and 4.9. Answer chapter 4 problems 36, 37, 38, 39 and 40. Find and traceroute to a server in 6 of the 7 continents on the planet earth. Explain any sudden jumps in round trip times in terms of a geographical route.
• Quiz 5: see [repo]/quiz/quiz5.txt. Due April 1.
• Quiz 6: see [repo]/quiz/quiz6.txt. Due April 8.

Projects for CSC424 Communications and Security.

Assignments:

• Project 1: Hamming code project. Due Wed, Feb 4.
• Example A: Netbounce
• Project 2: Packet Pass Around. Due Fri, Feb 20.
• Project 3: Truly Trivial File Transfer Protocol. Part A due Wed, Mar 6.
• Project 4: TTFTP Encryption option. Due Fri, Mar 27 Apr 3.
• Project 5: TTFTP Resend Timer Option. Due Fri, Apr 24.

General Requirements:

• Projects are programming projects, done in C on Unix.
• All reasonable effort shall be made to make your code platform independent, however your code must work on Ubuntu 14.04.
• Install Virtual Box, or similar, on your own machine to develop code locally on your own machine, if you are not running Ubuntu 14.04.
• Will also have a machine on Amazon AWS, and if you wish, a lab account can be made available.
• You will share and submit your projects using the departmental subversion site, svn.cs.miami.edu.
• Please refer to my subversion tutorial and the Subversion red book for information about subversion.
• You will use Makefiles so that the graders and assistants can build your projects from source, and are guided through your test suites.
• You will make test suites for your code. You shall not say simply "my project works". You will provide a test suite and what you will say is that, when the test suite is run, the expected behavior is observed.
• For Mac local development, download and install Apple's developer package, which is called Xcode. After installation, take the additional step to install the command line tools. Last time I did this, it was accomplished using "xcode-select --install" in a terminal window. However, xcode->open developer tools->more developer tools will open an Apple Developer login; register and login, and d/l the command line package and install.
• For Windows local developement, I recommend installing cygwin, https://www.cygwin.com/. In my experience, Visual Studio is powerful, but limited by being Microsoft-centric and lacking a command line development style. Meanwhile, several other important command line tools are missing from Windows. Install Cygwin and develop in a Unix-like environment in Windows.
• On a Mac, d/l and install TextWrangler, http://www.barebones.com/products/textwrangler/. This is my preferred WYSIWYG code editor. It allows you to edit a file remotely through SFTP. Set this up by including in .ssh/config a Host stanza and public key credentials so that authentication is automatic. See Nerderati.

Coding style:

• Your name and date must be in comments at the top of all files. I consider this your promise to me that this is your own work, or you have explained the source of the code otherwise.
• Use only lower-case in filenames, with exceptions for strong historical precedence: Makefile, README.TXT, maybe a few others. Never distinguish a file by case, and always refer to the file by the chosen case.
• Do not declare variables in the middle of a block. Reject this C99 feature. A variable's scope and lifetime should be a block, end of story. Coding is hard enough.
• Do not use Variable Length Arrays (VLA). Reject this C99 feature. They turn sizeof from a keyword into a function call, sometimes, and you now have run-time type errors as well as run-time allocation errors. Coding is hard enough without turning your back on the compiler's assistance in memory layout and type computation.
• You can use // on line comments.
• I'm conflicted on the use of zero-length arrays. Harbison and Steele tells me I'm an outlaw, but I can't seem to care. Your choice.
• Comment what isn't obvious. Comment what confused you when you wrote this code.
• Comment assumptions on parameters at the top of the function block.
• I prefer writing subroutines more basic first, so I don't need forward declarations. I consider this a huge hint to debuggers about what depends on what. I recommend not doing forward declarations unnecessarily.
• Use header files. Consider them as declaring your API. What's in the .h file explains what you intend to be the stable functions and types, as opposed to helper functions that might change.

Lab Accounts

1. A lab account as been set up for you, with username abcd424, if abcd is your subversion username. The lab account has the same initial password as the password to your subversion account. You can change the password on the lab account, but it won't change it on the subversion account.
2. You can work on the lab machines either in Ungar 426 or remotely. See the remote login information.
3. You can log into any of the machines in the lab, as the home directories are shared. However, these are not taken from the subversion sources, and as I will only consider files in subversion. I will not log into your lab account to look at files, or correct your work.

Ubuntu and Virtual Box

1. Install the latest version of Virtual Box
2. Download the ISO file for Ubuntu 14.04 LTS. I've had the best luck with 32-bit desktop.
3. Launch Virtual Box and create a new virtual machine: 2G mem, 32G disk, dynamic disk allocation, VDI format.
4. When it boots, it will ask for a disk. Browse to your ISO image (downloaded in step 2 above).
5. You might select LVM in the panel asking about the installation type.
6. Insert the Guest Additions from the Devices pull-down menu item, install and reboot.
7. Once booted again, open the terminal and "sudo apt-get update ; sudo apt-get upgrade" to bring your system up to date, the reboot. (Do this every so often, particularly if there are security related updates.)
8. Install the subversion client with "sudo apt-get install subversion". This is all I needed to get proj1 to build. The grader suggests "sudo apt-get install build-essential". I've done this in the past as well, when curses or make is not default installed. Keep it in mind if some buildtool doesn't seem to be installed.

MAC OSX

1. Install XCode on your Mac. It is available in the App Store for free.
2. Install the command line tools for XCode. Sometimes this happens by itself, and sometimes you have to make it happen. Worry about this only if working in a terminal the Mac seems not to know how to "make" or something like that.
3. Mac's ship with subversion. I dont' even think you need XCode for that.
4. Mac's ship with ssh. You can set up your ~/.ssh/config file, and make public keys, to make it easy to login and scp files.

Windows

1. Install cygwin.

References for CSC424 Communications and Security.