Cybersecurity & Systems Programming

Here includes my coding assignments from the class Introduction to Software Systems, involving low-level network server systems, Bash Scripts and C, ie. names in () are file names

Navigate to Bash folder

(ReadLog)

• ReadLog is a bash program that reads the data on jerrington.me.log
• Along with it involves 4 commands:
• unique-ips counts the number of unique ips
• reqs-per-day gives the average requests made per day
• most-popular-post analyzes the data and extracts the most popular post along with its number of requests
• total-transferred sums up the number of total volume of data transferred in bytes

FileSearching folder (search)

• by using ./search WHERE NAME, the program searches the WHERE directory for the NAME file and lists them out in stdout. (total-size)
• total-size is run using search, and uses its output to sum up the sizes of the files found

Now navigate to C folder

MathOperation folder (minicalc.c)

• minicalc is a C program that does the square root of a number, finds the greatest common divisor of more than 2 numbers, and checks if two strings are anagrams. (build)
• build is a bash file that compiles the minicalc.c program and also runs a series of tests to verify its output

Stringbuilder folder (minicalc.c)

• The same minicalc file with return values adjusted to output the different types of error properly (run-tests)
• Using Bash and creating a function to perform the error output better (stringbuilder.c)
• A C program using dynamic array to build strings, along with some tests in main function. (Makefile)
• By typing make in the terminal, it runs the Makefile
• make minicalc --> compiles minicalc.c
• make stringbuilder --> compiles stringbuilder.c
• make test --> runs ./run-tests

Server folder (server.c)

• a server created with C that allows a maximum connection of 4 (can be adjusted)
• port number is written as 4324 (can be adjusted)
• the server is able to transfer the messages from one client to all other clients (client.c)
• a client that connects to the 4324 port's server and is able to type messages to the server (Makefile)
• make compiles both the server file and client file

OffensiveSecurity(Hacking) folder (vulnerable.c)

• A vulnerable C program that contains a bug vulnerable to buffer-overflow attacks, which I will exploit and document in Solution.txt (Makefile)
• make compiles the vulnerable.c (Solution.txt)
• Documentation of the bug in vulnerable.c