Home
1unaram
Cancel

[Dreamhack] Background - Computer Science

๐Ÿ”ธ Linux Memory Layout [Study]Memory Layout Quiz: Linux Memory Layout #include <stdlib.h> int a = 0xa; const char b[] = "d_str"; int c; int foo(int arg) { int d = 0xd; return 0; } i...

[H4CKING GAME] REV - Keygen

# ๋ฌธ์ œ ํŒŒ์•… ๋ฌธ์ œ์—์„œ ์ฃผ์–ด์ง„ keygen.exe ํŒŒ์ผ์„ ์‹คํ–‰ํ•ด๋ณด๋‹ˆ ์•Œ๋งž์€ flag๋ฅผ ์ž…๋ ฅํ•ด์•ผ ํ•จ์„ ์•Œ ์ˆ˜ ์žˆ์—ˆ๋‹ค. IDA๋ฅผ ์ด์šฉํ•˜์—ฌ ์‹คํ–‰ ํŒŒ์ผ์„ ์—ด์–ด๋ณด์•˜๋‹ค. main ํ•จ์ˆ˜๋ฅผ ์ฐพ์„ ์ˆ˜ ์žˆ์—ˆ๊ณ , ๊ทธ๋ž˜ํ”„์—์„œ โ€œInput flag : โ€œ, โ€œNoโ€ฆ This is not flagโ€ฆโ€ ๋“ฑ์˜ ๋ฌธ์ž์—ด์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค. ๋‹คํ–‰ํžˆ๋„ ๋””์ปดํŒŒ์ผ...

[Study] Shell Metacharacter

๋ฉ”ํƒ€ ๋ฌธ์ž(Shell Metacharacter) ๋ฉ”ํƒ€ ๋ฌธ์ž ์„ค๋ช… ~ ํ™ˆ ๋””๋ ‰ํ† ๋ฆฌ . ํ˜„์žฌ ๋””๋ ‰ํ† ๋ฆฌ .. ์ƒ์œ„ ๋””๋ ‰ํ† ๋ฆฌ # ์ฃผ์„ ...

[Study] Objdump Opcode ์ถ”์ถœ ๋ช…๋ น์–ด

for i in $(objdump -d [file] | grep "^ " | cut -f 2); do echo -n \\x$i; done for i in $( ) : $( ) ๋‚ด์˜ ๋ช…๋ น์„ ์‹คํ–‰ํ•œ ๊ฐ’์„ ๋ฐ˜๋ณตํ•˜์—ฌ i๋กœ ์ ‘๊ทผ objdump -d [file_path] : [file] ๊ฒฝ๋กœ์˜ ์˜ค๋ธŒ์ ํŠธ ํŒŒ์ผ์„ ๊ธฐ๊ณ„์–ด๋กœ ์—ญ์–ด์…ˆ๋ธ” grep "^ " ...

[Study] pwntools & pwndbg

pwntools์™€ pwndbg๋ฅผ ์‚ฌ์šฉํ•˜๋ฉฐ ๊ณต๋ถ€ํ•˜๋Š” ๋‚ด์šฉ์„ ๊ณ„์† ์—…๋ฐ์ดํŠธ ํ•  ์˜ˆ์ •์ž…๋‹ˆ๋‹ค Reference : Dreamhack - [Tool: pwntools] # pwntools ๐Ÿ”Ž pwntools๋ž€? : ์‹œ์Šคํ…œ ํ•ดํ‚น์„ ์ˆ˜ํ–‰ํ•˜๋ฉฐ ์ž์ฃผ ์‚ฌ์šฉํ•˜๋Š” ํ•จ์ˆ˜๋“ค์„ ๊ตฌํ˜„ ํ•ด๋†“์€ ํŒŒ์ด์ฌ ๋ชจ๋“ˆ ๐Ÿ”ง pwntools ์„ค์น˜ & import # p...

[Dreamhack] Quiz: x86 Assembly 3

Dreamhack x86 Assembly ๊ฐ•์˜๋ฅผ ๋“ฃ๊ณ  ํ‘ผ Quiz๋ฅผ ์ •๋ฆฌํ•˜์˜€์Šต๋‹ˆ๋‹ค. # Quiz # ํ’€์ด [Code] main: push rbp mov rbp, rsp mov esi, 0xf mov rdi, 0x400500 call 0x400497 <write_n> m...

[Study] Regex ์ •๊ทœํ‘œํ˜„์‹

์ •๊ทœ ํ‘œํ˜„์‹์€ / (expression) / ๋กœ ํ‘œํ˜„ํ•œ๋‹ค. ์ •๊ทœ ํ‘œํ˜„์‹ Test Groups and Ranges | : ๋˜๋Š” () : ๊ทธ๋ฃน /gr(a|e)y/ : gr๊ณผ y ์‚ฌ์ด์— a ๋˜๋Š” e๊ฐ€ ์กด์žฌํ•˜๋Š” ๋ฌธ์ž (?:) : ์ฐพ์ง€๋งŒ ๊ธฐ์–ตํ•˜์ง€ ์•Š์Œ [] : ๋ฌธ์ž์…‹, ๊ด„ํ˜ธ...

[Study] Python - requests

ํŒจํ‚ค์ง€ ์„ค์น˜ pip install requests pip๋ฅผ ์ด์šฉํ•˜์—ฌ requests ๋ผ์ด๋ธŒ๋Ÿฌ๋ฆฌ๋ฅผ ์„ค์น˜ ์‚ฌ์šฉ๋ฒ• import requests from requests import * ์š”์ฒญ(Request) requests.request(method, url, **kwargs) Request Header requests...

[HackCTF] Welcome_rev

๐Ÿšฉ ๋ฌธ์ œ ์ •๋ณด #HackCTF #Reversing #Welcome_REV #50pts ๐Ÿšฉ ๋ฌธ์ œ ํ’€์ด ๐Ÿ‘โ€๐Ÿ—จ ๋ฌธ์ œ ํŒŒ์•… ์ฃผ์–ด์ง„ ํŒŒ์ผ์€ ํŒŒ์ผ ํ˜•์‹์„ ์•Œ ์ˆ˜ ์—†๋Š” ํŒŒ์ผ์ด์—ˆ๋‹ค. ์ด ํŒŒ์ผ์„ ๋ถ„์„ํ•˜์—ฌ flag๋ฅผ ์ฐพ์•„๋‚ด๋Š” ๊ฒƒ์œผ๋กœ ํŒŒ์•…ํ•˜์˜€๋‹ค. ๐Ÿ‘โ€๐Ÿ—จ ํ’€์ด ์‹œ๋„ ์šฐ์„  ์ฃผ์–ด์ง„ ํŒŒ์ผ์„ IDA์—์„œ ์—ด์–ด๋ณด์•˜๋‹ค ์ขŒ์ธก์˜ function ...

[Study] Register

๋ ˆ์ง€์Šคํ„ฐ๋ž€? : ๋ ˆ์ง€์Šคํ„ฐ(register)๋Š” CPU ๋‚ด๋ถ€์— ์กด์žฌํ•˜๋Š” ๋‹ค๋ชฉ์  ์ €์žฅ๊ณต๊ฐ„์œผ๋กœ์„œ, CPU๊ฐ€ ์š”์ฒญ์„ ์ฒ˜๋ฆฌํ•˜๋Š”๋ฐ ํ•„์š”ํ•œ ๋ฐ์ดํ„ฐ๋ฅผ ์ผ์‹œ์ ์œผ๋กœ ์ €์žฅ. ์‚ฐ์ˆ  ์—ฐ์‚ฐ์— ํ•„์š”ํ•œ ๋ฐ์ดํ„ฐ๋ฅผ ์ €์žฅํ•˜๊ฑฐ๋‚˜ ์ฃผ์†Œ๋ฅผ ์ €์žฅํ•˜๊ณ  ์ฐธ์กฐํ•˜๋Š” ๋“ฑ ๋‹ค์–‘ํ•œ ์šฉ๋„๋กœ ์‚ฌ์šฉ๋จ. ๋ ˆ์ง€์Šคํ„ฐ๋Š” 32bit ํ™˜๊ฒฝ์—์„œ๋Š” ์ฒซ ๊ธ€์ž๊ฐ€ E(Extended)๋กœ ์‹œ์ž‘ํ•˜๊ณ , 64bit ํ™˜๊ฒฝ์—์„œ๋Š” ...