# Cybersecurity Notes

## Cybersecurity Notes

- [Cybersecurity Notes](https://ir0nstone.gitbook.io/notes/readme.md)
- [Stack](https://ir0nstone.gitbook.io/notes/binexp/stack.md)
- [Introduction](https://ir0nstone.gitbook.io/notes/binexp/stack/introduction.md): An introduction to binary exploitation
- [ret2win](https://ir0nstone.gitbook.io/notes/binexp/stack/ret2win.md): The most basic binexp challenge
- [De Bruijn Sequences](https://ir0nstone.gitbook.io/notes/binexp/stack/de-bruijn-sequences.md): The better way to calculate offsets
- [Shellcode](https://ir0nstone.gitbook.io/notes/binexp/stack/shellcode.md): Running your own code
- [NOPs](https://ir0nstone.gitbook.io/notes/binexp/stack/nops.md): More reliable shellcode exploits
- [32- vs 64-bit](https://ir0nstone.gitbook.io/notes/binexp/stack/32-vs-64-bit.md): The differences between the sizes
- [No eXecute](https://ir0nstone.gitbook.io/notes/binexp/stack/no-execute.md): The defence against shellcode
- [Return-Oriented Programming](https://ir0nstone.gitbook.io/notes/binexp/stack/return-oriented-programming.md): Bypassing NX
- [Calling Conventions](https://ir0nstone.gitbook.io/notes/binexp/stack/return-oriented-programming/calling-conventions.md): A more in-depth look into parameters for 32-bit and 64-bit programs
- [Gadgets](https://ir0nstone.gitbook.io/notes/binexp/stack/return-oriented-programming/gadgets.md): Controlling execution with snippets of code
- [Exploiting Calling Conventions](https://ir0nstone.gitbook.io/notes/binexp/stack/return-oriented-programming/exploiting-calling-conventions.md): Utilising Calling Conventions
- [ret2libc/ret2system](https://ir0nstone.gitbook.io/notes/binexp/stack/return-oriented-programming/ret2libc.md): The standard ROP exploit
- [Stack Alignment](https://ir0nstone.gitbook.io/notes/binexp/stack/return-oriented-programming/stack-alignment.md): A minor issue
- [Format String Bug](https://ir0nstone.gitbook.io/notes/binexp/stack/format-string.md): Reading memory off the stack
- [Stack Canaries](https://ir0nstone.gitbook.io/notes/binexp/stack/canaries.md): The Buffer Overflow defence
- [PIE](https://ir0nstone.gitbook.io/notes/binexp/stack/pie.md): Position Independent Code
- [Pwntools, PIE and ROP](https://ir0nstone.gitbook.io/notes/binexp/stack/pie/pwntools-pie-and-rop.md)
- [PIE Bypass with Given Leak](https://ir0nstone.gitbook.io/notes/binexp/stack/pie/pie-exploit.md): Exploiting PIE with a given leak
- [PIE Bypass](https://ir0nstone.gitbook.io/notes/binexp/stack/pie/pie-bypass.md): Using format string
- [ASLR](https://ir0nstone.gitbook.io/notes/binexp/stack/aslr.md): Address Space Layout Randomisation
- [ASLR Bypass with Given Leak](https://ir0nstone.gitbook.io/notes/binexp/stack/aslr/aslr-bypass-with-given-leak.md)
- [PLT and GOT](https://ir0nstone.gitbook.io/notes/binexp/stack/aslr/plt_and_got.md): Bypassing ASLR
- [ret2plt ASLR bypass](https://ir0nstone.gitbook.io/notes/binexp/stack/aslr/ret2plt-aslr-bypass.md)
- [Virtual Addresses and Virtual Memory](https://ir0nstone.gitbook.io/notes/binexp/stack/virtual-addresses-and-virtual-memory.md)
- [GOT Overwrite](https://ir0nstone.gitbook.io/notes/binexp/stack/got-overwrite.md): Hijacking functions
- [Exploiting a GOT overwrite](https://ir0nstone.gitbook.io/notes/binexp/stack/got-overwrite/exploiting-a-got-overwrite.md)
- [RELRO](https://ir0nstone.gitbook.io/notes/binexp/stack/relro.md): Relocation Read-Only
- [Reliable Shellcode](https://ir0nstone.gitbook.io/notes/binexp/stack/reliable-shellcode.md): Shellcode, but without the guesswork
- [ROP and Shellcode](https://ir0nstone.gitbook.io/notes/binexp/stack/reliable-shellcode/rop-and-shellcode.md)
- [Using RSP](https://ir0nstone.gitbook.io/notes/binexp/stack/reliable-shellcode/using-rsp.md)
- [ret2reg](https://ir0nstone.gitbook.io/notes/binexp/stack/reliable-shellcode/ret2reg.md): Using Registers to bypass ASLR
- [Using ret2reg](https://ir0nstone.gitbook.io/notes/binexp/stack/reliable-shellcode/ret2reg/using-ret2reg.md)
- [One Gadgets and Malloc Hook](https://ir0nstone.gitbook.io/notes/binexp/stack/one-gadgets-and-malloc-hook.md): Quick shells and pointers
- [Syscalls](https://ir0nstone.gitbook.io/notes/binexp/stack/syscalls.md): Interfacing directly with the kernel
- [Exploitation with Syscalls](https://ir0nstone.gitbook.io/notes/binexp/stack/syscalls/exploitation-with-syscalls.md)
- [Sigreturn-Oriented Programming (SROP)](https://ir0nstone.gitbook.io/notes/binexp/stack/syscalls/sigreturn-oriented-programming-srop.md): Controlling all registers at once
- [Using SROP](https://ir0nstone.gitbook.io/notes/binexp/stack/syscalls/sigreturn-oriented-programming-srop/using-srop.md)
- [ret2dlresolve](https://ir0nstone.gitbook.io/notes/binexp/stack/ret2dlresolve.md): Resolving our own libc functions
- [Exploitation](https://ir0nstone.gitbook.io/notes/binexp/stack/ret2dlresolve/exploitation.md)
- [ret2csu](https://ir0nstone.gitbook.io/notes/binexp/stack/ret2csu.md): Controlling registers when gadgets are lacking
- [Exploitation](https://ir0nstone.gitbook.io/notes/binexp/stack/ret2csu/exploitation.md)
- [CSU Hardening](https://ir0nstone.gitbook.io/notes/binexp/stack/ret2csu/csu-hardening.md)
- [Exploiting over Sockets](https://ir0nstone.gitbook.io/notes/binexp/stack/exploiting-over-sockets.md): File Descriptors and Sockets
- [Exploit](https://ir0nstone.gitbook.io/notes/binexp/stack/exploiting-over-sockets/exploit.md): Duplicating the Descriptors
- [Socat](https://ir0nstone.gitbook.io/notes/binexp/stack/exploiting-over-sockets/socat.md): More on socat
- [Forking Processes](https://ir0nstone.gitbook.io/notes/binexp/stack/forking-processes.md): Flaws with fork()
- [Stack Pivoting](https://ir0nstone.gitbook.io/notes/binexp/stack/stack-pivoting.md): Lack of space for ROP
- [Exploitation](https://ir0nstone.gitbook.io/notes/binexp/stack/stack-pivoting/exploitation.md): Stack Pivoting
- [pop rsp](https://ir0nstone.gitbook.io/notes/binexp/stack/stack-pivoting/exploitation/pop-rsp.md): Using a pop rsp gadget to stack pivot
- [leave](https://ir0nstone.gitbook.io/notes/binexp/stack/stack-pivoting/exploitation/leave.md): Using leave; ret to stack pivot
- [Pointer Authentication](https://ir0nstone.gitbook.io/notes/binexp/stack/pointer-authentication.md): An Arm hardware protection to combat ROP
- [Memory Tagging Extension (MTE)](https://ir0nstone.gitbook.io/notes/binexp/stack/memory-tagging-extension-mte.md): Arm's MTE Hardware Protection
- [Memory Integrity Enforcement](https://ir0nstone.gitbook.io/notes/binexp/stack/memory-integrity-enforcement.md)
- [Heap](https://ir0nstone.gitbook.io/notes/binexp/heap.md): Still learning :)
- [Introduction to the Heap](https://ir0nstone.gitbook.io/notes/binexp/heap/introduction-to-the-heap.md)
- [Chunks](https://ir0nstone.gitbook.io/notes/binexp/heap/chunks.md)
- [Freeing Chunks and the Bins](https://ir0nstone.gitbook.io/notes/binexp/heap/bins.md)
- [Operations of the Fastbin](https://ir0nstone.gitbook.io/notes/binexp/heap/bins/operations-of-the-fastbin.md)
- [Operations of the Other Bins](https://ir0nstone.gitbook.io/notes/binexp/heap/bins/chunk-allocation-and-reallocation.md)
- [The Top Chunk and Remainder](https://ir0nstone.gitbook.io/notes/binexp/heap/the-top-chunk-and-remainder.md): Creating more heap space
- [Malloc State](https://ir0nstone.gitbook.io/notes/binexp/heap/malloc-state.md)
- [malloc\_consolidate()](https://ir0nstone.gitbook.io/notes/binexp/heap/malloc_consolidate.md): Consolidating fastbins
- [Heap Overflow](https://ir0nstone.gitbook.io/notes/binexp/heap/heap-overflow.md)
- [heap0](https://ir0nstone.gitbook.io/notes/binexp/heap/heap-overflow/heap0.md): http://exploit.education/phoenix/heap-zero/
- [heap1](https://ir0nstone.gitbook.io/notes/binexp/heap/heap-overflow/heap1.md): http://exploit.education/phoenix/heap-one/
- [Use-After-Free](https://ir0nstone.gitbook.io/notes/binexp/heap/use-after-free.md)
- [Double-Free](https://ir0nstone.gitbook.io/notes/binexp/heap/double-free.md)
- [Double-Free Protections](https://ir0nstone.gitbook.io/notes/binexp/heap/double-free/double-free-protections.md)
- [Double-Free Exploit](https://ir0nstone.gitbook.io/notes/binexp/heap/double-free/double-free-exploit.md)
- [Unlink Exploit](https://ir0nstone.gitbook.io/notes/binexp/heap/unlink-exploit.md)
- [The Tcache](https://ir0nstone.gitbook.io/notes/binexp/heap/the-tcache.md): New and efficient heap management
- [Tcache: calloc()](https://ir0nstone.gitbook.io/notes/binexp/heap/the-tcache/tcache-calloc.md)
- [Tcache Poisoning](https://ir0nstone.gitbook.io/notes/binexp/heap/the-tcache/tcache-poisoning.md): Reintroducing double-frees
- [The Malloc Maleficarum](https://ir0nstone.gitbook.io/notes/binexp/heap/the-malloc-maleficarum.md): The first heap exploits
- [The House of Force](https://ir0nstone.gitbook.io/notes/binexp/heap/the-malloc-maleficarum/the-house-of-force.md): Exploiting the wilderness
- [Tcache Keys](https://ir0nstone.gitbook.io/notes/binexp/heap/tcache-keys.md): A primitive double-free protection
- [Safe Linking](https://ir0nstone.gitbook.io/notes/binexp/heap/safe-linking.md)
- [Kernel](https://ir0nstone.gitbook.io/notes/binexp/kernel.md)
- [Introduction](https://ir0nstone.gitbook.io/notes/binexp/kernel/introduction.md)
- [Writing a Char Module](https://ir0nstone.gitbook.io/notes/binexp/kernel/writing-a-char-module.md)
- [An Interactive Char Driver](https://ir0nstone.gitbook.io/notes/binexp/kernel/writing-a-char-module/a-communicatable-char-driver.md)
- [Interactivity with IOCTL](https://ir0nstone.gitbook.io/notes/binexp/kernel/writing-a-char-module/interactivity-with-ioctl.md): A more useful way to interact with the driver
- [A Basic Kernel Interaction Challenge](https://ir0nstone.gitbook.io/notes/binexp/kernel/a-basic-kernel-interaction-challenge.md)
- [Compiling, Customising and booting the Kernel](https://ir0nstone.gitbook.io/notes/binexp/kernel/compiling-customising-and-booting-the-kernel.md): Instructions for compiling the kernel with your own settings, as well as compiling kernel modules for a specific kernel version.
- [Double-Fetch](https://ir0nstone.gitbook.io/notes/binexp/kernel/double-fetch.md): The most simple of vulnerabilities
- [Double-Fetch without Sleep](https://ir0nstone.gitbook.io/notes/binexp/kernel/double-fetch/double-fetch-without-sleep.md): Removing the artificial sleep
- [The Ultimate Aim of Kernel Exploitation - Process Credentials](https://ir0nstone.gitbook.io/notes/binexp/kernel/the-ultimate-aim-of-kernel-exploitation-process-credentials.md)
- [Kernel ROP - ret2usr](https://ir0nstone.gitbook.io/notes/binexp/kernel/kernel-rop-ret2usr.md): ROPpety boppety, but now in the kernel
- [Debugging a Kernel Module](https://ir0nstone.gitbook.io/notes/binexp/kernel/debugging-a-kernel-module.md): A practical example
- [SMEP](https://ir0nstone.gitbook.io/notes/binexp/kernel/smep.md): Supervisor Memory Execute Protection
- [Kernel ROP - Disabling SMEP](https://ir0nstone.gitbook.io/notes/binexp/kernel/smep/kernel-rop-disabling-smep.md): An old technique
- [Kernel ROP - Privilege Escalation in Kernel Space](https://ir0nstone.gitbook.io/notes/binexp/kernel/smep/kernel-rop-privilege-escalation-in-kernel-space.md): Bypassing SMEP by ropping through the kernel
- [Kernel ROP - Stack Pivoting](https://ir0nstone.gitbook.io/notes/binexp/kernel/smep/kernel-rop-stack-pivoting.md)
- [SMAP](https://ir0nstone.gitbook.io/notes/binexp/kernel/smap.md): Supervisor Memory Access Protection
- [Overwriting modprobe\_path](https://ir0nstone.gitbook.io/notes/binexp/kernel/modprobe_path.md): A simple way to pop a shell
- [KASLR](https://ir0nstone.gitbook.io/notes/binexp/kernel/kaslr.md)
- [KPTI](https://ir0nstone.gitbook.io/notes/binexp/kernel/kpti.md): Kernel Page Table Isolation
- [Kernel Heap](https://ir0nstone.gitbook.io/notes/binexp/kernel/page.md): The pain of it all
- [Heap Structures](https://ir0nstone.gitbook.io/notes/binexp/kernel/heap-structures.md)
- [TODO](https://ir0nstone.gitbook.io/notes/binexp/kernel/todo.md): Random stuff I want to mention somewhere, but too small for its own page
- [Browser Exploitation](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation.md)
- [\*CTF 2019 - oob-v8](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation/ctf-2019-oob-v8.md): Setting Up
- [The Challenge](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation/ctf-2019-oob-v8/the-challenge.md): The actual challenge
- [picoCTF 2021 - Kit Engine](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation/picoctf-2021-kit-engine.md): A lesson in floating-point form
- [picoCTF 2021 - Download Horsepower](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation/picoctf-2021-download-horsepower.md): Another OOB, but with pointer compression
- [Browser Architecture](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation/browser-architecture.md): A look at how browsers work under the hood
- [Operation of the Renderer](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation/browser-architecture/operation-of-the-renderer.md): How the renderer process works
- [An Introduction to Turbofan](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation/an-introduction-to-turbofan.md): V8's Optimizer
- [A Typer Bug](https://ir0nstone.gitbook.io/notes/binexp/browser-exploitation/an-introduction-to-turbofan/a-typer-bug.md): One of my favourites
- [Memory Safety](https://ir0nstone.gitbook.io/notes/binexp/memory-safety.md): Languages like Rust and Swift claim to be "memory-safe". What does that mean?
- [C++ Smart Pointers](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/c++-smart-pointers.md): C++'s foray into memory safety
- [RAII (Resource Acquisition is Initialization)](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/raii-resource-acquisition-is-initialization.md)
- [Garbage Collection](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/garbage-collection.md)
- [Tracing Garbage Collection](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/garbage-collection/tracing-garbage-collection.md)
- [Automatic Reference Counting](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/garbage-collection/automatic-reference-counting.md): Apple's preferred approach to automatic memory management
- [Rust](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/rust.md): The poster child for memory safety
- [Python (and C#, Java)](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/python-and-c-java.md)
- [Swift](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/swift.md): Swift uses purely ARC. How does it fix the problems that arise without a tracing garbage collector?
- [Sandboxing](https://ir0nstone.gitbook.io/notes/binexp/memory-safety/sandboxing.md)
- [Dynamic Binary Instrumentation](https://ir0nstone.gitbook.io/notes/binexp/dynamic-binary-instrumentation.md): Manipulating programs without the source
- [Strings in C++](https://ir0nstone.gitbook.io/notes/rev/strings-in-c++.md)
- [C++ Decompilation Tricks](https://ir0nstone.gitbook.io/notes/rev/c++-decompilation-tricks.md): How decompilers do stuff
- [Reverse Engineering ARM](https://ir0nstone.gitbook.io/notes/rev/reverse-engineering-arm.md): Just a ragged collection of notes before I do anything proper - do not take this as gospel! I am doing ARM reversing on my M1 MacBook for fun...
- [Introduction](https://ir0nstone.gitbook.io/notes/cryptography/introduction.md)
- [Number Theory Fundamentals](https://ir0nstone.gitbook.io/notes/cryptography/number-theory-fundamentals.md)
- [Divisibility, Factors and Euclid's Algorithms](https://ir0nstone.gitbook.io/notes/cryptography/number-theory-fundamentals/divisibility-factors-and-euclids-algorithms.md): An outline of the fundamentals of number theory
- [Modular Arithmetic](https://ir0nstone.gitbook.io/notes/cryptography/number-theory-fundamentals/modular-arithmetic.md): An introduction to the fundamentals
- [Rings, Fields and Euler's Totient Function](https://ir0nstone.gitbook.io/notes/cryptography/number-theory-fundamentals/rings-fields-and-eulers-totient-function.md): The basics of Rings, Fields and Euler's Phi Function
- [Continued Fractions](https://ir0nstone.gitbook.io/notes/cryptography/continued-fractions.md)
- [RSA](https://ir0nstone.gitbook.io/notes/cryptography/overview.md)
- [Public Exponent Attacks](https://ir0nstone.gitbook.io/notes/cryptography/overview/public-exponent-attacks.md)
- [e=1](https://ir0nstone.gitbook.io/notes/cryptography/overview/public-exponent-attacks/e-1.md)
- [Small e](https://ir0nstone.gitbook.io/notes/cryptography/overview/public-exponent-attacks/small-e.md)
- [Multi-party RSA with Small e](https://ir0nstone.gitbook.io/notes/cryptography/overview/public-exponent-attacks/multi-party-rsa-with-small-e.md)
- [Wiener's Attack](https://ir0nstone.gitbook.io/notes/cryptography/overview/public-exponent-attacks/wieners-attack.md): Using Continued Fractions to attack large e values
- [Choice of Primes](https://ir0nstone.gitbook.io/notes/cryptography/overview/choice-of-primes.md)
- [N is prime](https://ir0nstone.gitbook.io/notes/cryptography/overview/choice-of-primes/n-is-prime.md)
- [Mersenne Primes](https://ir0nstone.gitbook.io/notes/cryptography/overview/choice-of-primes/mersenne-primes.md)
- [P=Q](https://ir0nstone.gitbook.io/notes/cryptography/overview/choice-of-primes/p-q.md)
- [Fermat Factorisation](https://ir0nstone.gitbook.io/notes/cryptography/overview/choice-of-primes/fermat-factorisation.md): Used when p and q are numericaly close
- [Factorisation Methods](https://ir0nstone.gitbook.io/notes/cryptography/overview/factorisation-methods.md)
- [Pollard's p-1](https://ir0nstone.gitbook.io/notes/cryptography/overview/factorisation-methods/pollards-p-1.md): Factorising N when we know a factor is smooth
- [Diffie-Hellman Key Exchange](https://ir0nstone.gitbook.io/notes/cryptography/overview-1.md)
- [Solving the DLP](https://ir0nstone.gitbook.io/notes/cryptography/overview-1/solving-the-dlp.md)
- [Baby Step, Giant Step](https://ir0nstone.gitbook.io/notes/cryptography/overview-1/solving-the-dlp/baby-step-giant-step.md): The simple iterative approach
- [An Introduction to Blockchain](https://ir0nstone.gitbook.io/notes/blockchain/an-introduction-to-blockchain.md)
- [Smart Contracts and Solidity](https://ir0nstone.gitbook.io/notes/blockchain/smart-contracts-and-solidity.md)
- [Hosting a Testnet and Deploying a Contract](https://ir0nstone.gitbook.io/notes/blockchain/hosting-a-testnet-and-deploying-a-contract.md): Using Foundry to start a local testnet and deploy a Solidity contract.
- [Interacting with Python](https://ir0nstone.gitbook.io/notes/blockchain/interacting-with-python.md): Using web3.py
- [Ethereum Overview](https://ir0nstone.gitbook.io/notes/blockchain/ethereum-overview.md): The one we need to understand
- [Hack The Box](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box.md)
- [Linux Machines](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/linux-machines.md)
- [Easy](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/linux-machines/easy-linux.md)
- [Traceback](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/linux-machines/easy-linux/traceback.md)
- [Medium](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/linux-machines/medium.md)
- [Magic](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/linux-machines/medium/magic.md): SQL injection, PHP reverse shell upload, mysqldump and PATH injection
- [UpDown](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/linux-machines/medium/updown.md): LFI to RCE using PHAR files while bypassing disabled\_functions, followed by abuse of SUID and sudo.
- [Hard](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/linux-machines/hard.md)
- [Intense](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/linux-machines/hard/intense.md): SQL Injection, Hash Length Extension, LFI and binary exploitation
- [Challenges](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges.md)
- [Web](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/web.md)
- [Looking Glass](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/web/looking-glass.md)
- [Sanitize](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/web/sanitize.md)
- [Baby Auth](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/web/baby-auth.md)
- [Baby Website Rick](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/web/baby-website-rick.md)
- [Pwn](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/pwn.md)
- [Dream Diary: Chapter 1](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/pwn/dream-diary-chapter-1.md)
- [Unlink Exploit](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/pwn/dream-diary-chapter-1/unlink-exploit.md)
- [Chunk Overlap](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/pwn/dream-diary-chapter-1/chunk-overlap.md)
- [Ropme](https://ir0nstone.gitbook.io/notes/writeups/hack-the-box/challenges/pwn/ropme.md)
- [picoGym](https://ir0nstone.gitbook.io/notes/writeups/picogym.md): picoGym contains all of the past challenges from previous picoCTF events and can be found at https://play.picoctf.org/practice
- [Cryptography](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography.md)
- [Mod 26](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/mod-26.md): Cryptography can be easy, do you know what ROT13 is? cvpbPGS{arkg\_gvzr\_V'yy\_gel\_2\_ebhaqf\_bs\_ebg13\_uJdSftmh}
- [Mind Your Ps and Qs](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/mind-your-ps-and-qs.md): In RSA, a small e value can be problematic, but what about N? Can you decrypt this? values
- [Easy Peasy](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/easy-peasy.md): A one-time pad is unbreakable, but can you manage to recover the flag? (Wrap with picoCTF{}) nc mercury.picoctf.net 11188 otp.py
- [The Numbers](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/the-numbers.md): The numbers... what do they mean?
- [New Caesar](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/new-caesar.md): We found a brand new type of encryption, can you break the secret code? (Wrap with picoCTF{}) apbopjbobpnjpjnmnnnmnlnbamnpnononpnaaaamnlnkapndnkncamnpapncnbannaapncndnlnpna new\_caesar.py
- [Mini RSA](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/mini-rsa.md): What happens if you have a small exponent? There is a twist though, we padded the plaintext so that (M \*\* e) is just barely larger than N. Let's decrypt this: ciphertext
- [Dachshund Attacks](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/dachshund-attacks.md): What if d is too small? Connect with nc mercury.picoctf.net 37455.
- [No Padding, No Problem](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/no-padding-no-problem.md): Oracles can be your best friend, they will decrypt anything, except the flag's ciphertext. How will you break it? Connect with nc mercury.picoctf.net 10333
- [Easy1](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/easy1.md): The one time pad can be cryptographically secure, but not when you know the key. Can you solve this? We've given you the encrypted flag, key, and a table to help UFJKXQZQUNB with the key of SOLVECRYPT
- [13](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/13.md): Cryptography can be easy, do you know what ROT13 is? cvpbPGS{abg\_gbb\_onq\_bs\_n\_ceboyrz}
- [Caesar](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/caesar.md): Decrypt this message.
- [Pixelated](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/pixelated.md): I have these 2 images, can you make a flag out of them? scrambled1.png scrambled2.png
- [Basic-Mod1](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/basic-mod1.md): Take each number mod 37 and map it to the following character set: 0-25 is the alphabet (uppercase), 26-35 are the decimal digits, and 36 is an underscore. Wrap your decrypted message in picoCTF.
- [Basic-Mod2](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/basic-mod2.md)
- [Credstuff](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/credstuff.md): We found a leak of a blackmarket website's login credentials. Can you find the password of the user cultiris and successfully decrypt it? Download the leak here.
- [morse-code](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/morse-code.md)
- [rail-fence](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/rail-fence.md): A type of transposition cipher is the rail fence cipher, which is described here. Here is one such cipher encrypted using the rail fence with 4 rails. Can you decrypt it?
- [Substitution0](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/substitution0.md): A message has come in but it seems to be all scrambled. Luckily it seems to have the key at the beginning. Can you crack this substitution cipher?
- [Substitution1](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/substitution1.md): A second message has come in the mail, and it seems almost identical to the first one. Maybe the same thing will work again.
- [Substitution2](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/substitution2.md): It seems that another encrypted message has been intercepted. The encryptor seems to have learned their lesson though and now there isn't any punctuation! Can you still crack the cipher?
- [Transposition-Trial](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/transposition-trial.md): Our data got corrupted on the way here. Luckily, nothing got replaced, but every block of 3 got scrambled around!
- [Vigenere](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/vigenere.md): Can you decrypt this message?
- [HideToSee](https://ir0nstone.gitbook.io/notes/writeups/picogym/cryptography/hidetosee.md): How about some hide and seek heh? Look at this image here.
- [CTFs](https://ir0nstone.gitbook.io/notes/writeups/ctfs.md)
- [Fword CTF 2020](https://ir0nstone.gitbook.io/notes/writeups/ctfs/fword-ctf-2020.md): https://ctftime.org/event/1066
- [Binary Exploitation](https://ir0nstone.gitbook.io/notes/writeups/ctfs/fword-ctf-2020/binary-exploitation.md)
- [Molotov](https://ir0nstone.gitbook.io/notes/writeups/ctfs/fword-ctf-2020/binary-exploitation/untitled.md): A ret2libc with a given leak
- [Reversing](https://ir0nstone.gitbook.io/notes/writeups/ctfs/fword-ctf-2020/reversing.md)
- [XO](https://ir0nstone.gitbook.io/notes/writeups/ctfs/fword-ctf-2020/reversing/xo.md): Messing with the XOR
- [X-MAS CTF 2020](https://ir0nstone.gitbook.io/notes/writeups/ctfs/x-mas-ctf-2020.md)
- [Pwn](https://ir0nstone.gitbook.io/notes/writeups/ctfs/x-mas-ctf-2020/pwn.md)
- [Do I Know You?](https://ir0nstone.gitbook.io/notes/writeups/ctfs/x-mas-ctf-2020/pwn/do-i-know-you.md)
- [Naughty](https://ir0nstone.gitbook.io/notes/writeups/ctfs/x-mas-ctf-2020/pwn/naughty.md)
- [Web](https://ir0nstone.gitbook.io/notes/writeups/ctfs/x-mas-ctf-2020/web.md)
- [PHP Master](https://ir0nstone.gitbook.io/notes/writeups/ctfs/x-mas-ctf-2020/web/php-master.md)
- [HTB CyberSanta 2021](https://ir0nstone.gitbook.io/notes/writeups/ctfs/htb-cybersanta-2021.md)
- [Crypto](https://ir0nstone.gitbook.io/notes/writeups/ctfs/htb-cybersanta-2021/crypto.md)
- [Common Mistake](https://ir0nstone.gitbook.io/notes/writeups/ctfs/htb-cybersanta-2021/crypto/common-mistake.md): Common Mod, DIfferent e
- [Missing Reindeer](https://ir0nstone.gitbook.io/notes/writeups/ctfs/htb-cybersanta-2021/crypto/missing-reindeer.md): Cube Root Attack
- [Xmas Spirit](https://ir0nstone.gitbook.io/notes/writeups/ctfs/htb-cybersanta-2021/crypto/xmas-spirit.md)
- [Meet Me Halfway](https://ir0nstone.gitbook.io/notes/writeups/ctfs/htb-cybersanta-2021/crypto/meet-me-halfway.md): Meet-in-the-middle attack on AES
- [pwntools](https://ir0nstone.gitbook.io/notes/misc/pwntools.md)
- [Introduction](https://ir0nstone.gitbook.io/notes/misc/pwntools/introduction.md)
- [Processes and Communication](https://ir0nstone.gitbook.io/notes/misc/pwntools/processes_and_communication.md)
- [Logging and Context](https://ir0nstone.gitbook.io/notes/misc/pwntools/logging_and_context.md)
- [Packing](https://ir0nstone.gitbook.io/notes/misc/pwntools/packing.md)
- [ELF](https://ir0nstone.gitbook.io/notes/misc/pwntools/elf.md)
- [ROP](https://ir0nstone.gitbook.io/notes/misc/pwntools/rop.md)
- [scanf Bypasses](https://ir0nstone.gitbook.io/notes/misc/scanf-bypasses.md)
- [Challenges in Containers](https://ir0nstone.gitbook.io/notes/misc/challenges-in-containers.md)
- [Using Z3](https://ir0nstone.gitbook.io/notes/misc/using-z3.md): Microsoft's Theorem Prover
- [Cross-Compiling for arm32](https://ir0nstone.gitbook.io/notes/misc/cross-compiling-for-arm32.md): Absolute pain
- [CodeQL](https://ir0nstone.gitbook.io/notes/misc/codeql.md): Querying code to find vulnerabilities


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