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Dreamhack - ์›Œ๊ฒŒ์ž„, rev-basic-2 ํ’€์ด

by Janger 2021. 12. 3.
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https://dreamhack.io/wargame/challenges/16/

 

rev-basic-2

Reversing Basic Challenge #2 ์ด ๋ฌธ์ œ๋Š” ์‚ฌ์šฉ์ž์—๊ฒŒ ๋ฌธ์ž์—ด ์ž…๋ ฅ์„ ๋ฐ›์•„ ์ •ํ•ด์ง„ ๋ฐฉ๋ฒ•์œผ๋กœ ์ž…๋ ฅ๊ฐ’์„ ๊ฒ€์ฆํ•˜์—ฌ correct ๋˜๋Š” wrong์„ ์ถœ๋ ฅํ•˜๋Š” ํ”„๋กœ๊ทธ๋žจ์ด ์ฃผ์–ด์ง‘๋‹ˆ๋‹ค. ํ•ด๋‹น ๋ฐ”์ด๋„ˆ๋ฆฌ๋ฅผ ๋ถ„์„ํ•˜์—ฌ correct๋ฅผ ์ถœ

dreamhack.io

 

์ด๋ฒˆ์—๋Š” ๋ฐฐ์—ด์„ ๋น„๊ตํ•ด๊ฐ€๋ฉด์„œ ๋‚ด๊ฐ€ ์ž…๋ ฅํ•œ ๋ฌธ์ž์—ด์ด ์žฅ๋‹ต ๋ฐฐ์—ด์ด ๊ฐ€์ง€๊ณ  ์žˆ๋Š” ๋ฌธ์ž์™€ ๋˜‘๊ฐ™์€์ง€๋ฅผ ๋น„๊ตํ•˜๋Š” ์›๋ฆฌ์˜€๋‹ค. 

 

 

์ด๋ ‡๊ฒŒ ์ฃผ์„์„ ์ ์–ด๊ฐ€๋ฉด์„œ ํ•˜๋ฉด ์ดํ•ดํ•˜๊ธฐ๊ฐ€ ์‰ฝ๋‹ค. 

 

 

ํ”„๋กœ๊ทธ๋žจ์ด ๊ณ„์†ํ•ด์„œ ์ฐธ์กฐํ•˜๋Š” ์ € ๋ฐฐ์—ด์˜ ์ฃผ์†Œ๋ฅผ ๋คํ”„ ์ฐฝ์—์„œ ๋”ฐ๋ผ๊ฐ€ ๋ณด์•˜๋”๋‹ˆ 

"Comp4re_the_arr4y"๋ผ๊ณ  ๋ฐฐ์—ด์ด ๊ฐ 4๋ฐ”์ดํŠธ ๋–จ์–ด์ง„ ๊ฐ„๊ฒฉ์œผ๋กœ ์ €์žฅ์ด ๋˜์–ด์žˆ์—ˆ๋‹ค. 

 

๊ทธ๋ ‡๊ธฐ ๋•Œ๋ฌธ์— cmp ๋ถ€๋ถ„์—์„œ [rcx+rax*4] ์ด๋Ÿฐ ์‹์œผ๋กœ ( index * 4 )๋ฅผ ํ•œ ์ด์œ ๊ฐ€ ๋ฐฐ์—ด์„ ํ•œ ์—ด์”ฉ ํ•œ ์—ด์”ฉ ์ฐธ์กฐ๋ฅผ ํ•˜๊ธฐ ์œ„ํ•ด์„œ์ธ๊ฐ€ ๋ณด๋‹ค. 

 

 

while(count >= 12){
	
    if( my_input[count] == solve_array[count] ){ } 
    else {
    	return 0; // ZF
    }

    count++;
}

return 1;

์ด๋Ÿฐ ์‹์œผ๋กœ ์ฝ”๋“œ๋ฅผ ์งœ๋ฉด ๊ฒฐ๊ณผ๊ฐ€ ๋˜‘๊ฐ™์ง€ ์•Š์„๊นŒ

 

 

 

 

 

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