CTF & Practice Challenges

This section contains two types of content: NCL competition prep (cybersecurity challenges) and C programming practice (CodeStepByStep exercises linked to course topics). The NCL material prepares you for the National Cyber League competition. The programming practice reinforces what you learn in lectures.

---

NCL Competition Prep

The National Cyber League (NCL) is a semester-long cybersecurity competition with 9 challenge categories. These pages cover each category with tool references, walkthroughs, and practice resources. The NCL skill tree in the Skill Tree tracks your progress across these areas.

OSINT & Intelligence

• Open Source Intelligence — DNS, WHOIS, metadata extraction, HTTP headers, PGP, threat intel, SSL/TLS certificates
• Scanning & Reconnaissance — nmap, port scanning, service detection, OS fingerprinting

Cryptography & Password Cracking

• Cryptography — Encoding identification, Caesar, Vigenere, Rail Fence, Base64, RSA
• Password Cracking — John the Ripper, hashcat, hash identification, wordlists, mask attacks

Forensics & Analysis

• Digital Forensics — File carving, magic bytes, binwalk, Volatility memory analysis, git forensics
• Log Analysis — SSH logs, web server logs, syslog, incident timeline reconstruction
• Network Traffic Analysis — Wireshark, tshark, PCAP filtering, credential extraction, attack detection

Exploitation

• Web Application Security — SQL injection, XSS, command injection, directory traversal, IDOR
• Enumeration & Exploitation — Binary analysis, GDB, buffer overflows, format strings, reverse engineering

---

C Programming Practice

These are CodeStepByStep exercises organized by topic. Each set is linked from the lesson where the concept is taught — you can also access them directly here. Work through them after reading the corresponding lesson.

Weeks 3-4: C Foundations

• Programming Basics — 13 exercises · printf, scanf, functions, basic I/O
• Expressions & Type Conversion — 2 exercises · Operator precedence, casting
• If/Else Decisions — 4 exercises · Conditionals, control flow
• Loops — 29 exercises · for, while, nested loops
• Parameters & Return Values — 27 exercises · Pass-by-value, function tracing
• Bitwise Operations — 23 exercises · &, |, ^, ~, <<, >>

Week 5: Arrays & Strings

• Arrays — 12 exercises · Traversal, manipulation, bounds
• Strings — 11 exercises · string.h functions, char arrays

Weeks 6-7: Pointers & Memory

• Pointers — 10 exercises · &, *, arithmetic, double pointers
• Dynamic Memory — 8 exercises · calloc, free, Valgrind

Weeks 8-9: Advanced C

• Structs — 6 exercises · typedef, struct pointers
• File I/O — 4 exercises · fopen, fscanf, fgets
• Function Pointers & Generics — 8 exercises · Callbacks, qsort, void *

Cross-Cutting

• Secure Coding — 6 exercises · Buffer overflows, input validation

---

External Practice Platforms

Free platforms for additional practice beyond course content:

• pwn.college — ASU’s binary exploitation platform (1000+ challenges)
• picoCTF — CMU’s educational CTF with learning guides
• TryHackMe — Guided cybersecurity rooms
• HackTheBox — Real machines to hack
• CryptoHack — Cryptography challenges
• PortSwigger Web Security Academy — Web vulnerability labs
• CyberDefenders — Blue team forensics challenges