Python solution script for ASM2 challenge from zh3r0 CTF '20

asm2_crack.py

'''
Challenge Source Backup :
https://gist.github.com/mrT4ntr4/4e02a52c0bc89ecac7f03e38e0934628

Manually dissecting the assembly code and porting it to python
'''

def f(x):
	if(x):
		if(x != 1):
			res3 = f(x-1)
			res4 = f(x-2)
			final_res = res3 + res4
			return final_res		
		return 1
	return 0


def start(arg1,arg2):
	res1 = f(arg1)   # [rbp-4]
	res2 = f(arg2)   # [rbp-8]
	print res1,res2

	got1 = 0
	got2 = 0

	while (res1):
		ecx = ((((res1 * 1717986919)>>32)/4) - (res1>>31))
		eax = ecx * 4
		eax += ecx
		eax += eax
		ecx = res1 - eax

		edx = ((res1 * 1717986919) >> 32)/4 - (res1>>31)
		eax = edx * 4
		eax += edx
		eax += eax
		esi = res1 - eax

		eax = esi * ecx

		got1 += eax  # [rbp-12]

		res1 = ((res1 * 1717986919) >> 32)/4 - (res1>>31)


	while (res2):
		ecx = ((((res2 * 1717986919)>>32)/4) - (res2>>31))
		eax = ecx*4
		eax += ecx
		eax += eax
		ecx = res2 - eax

		edx = ((res2 * 1717986919) >> 32)/4 - (res2>>31)
		eax = edx * 4
		eax += edx
		eax += eax
		esi = res2 - eax

		eax = esi * ecx

		got2 += eax  # [rbp-16]

		res2 = ((res2 * 1717986919) >> 32)/4 - (res2>>31)


	print got1, got2

	got_final = 0 # [rbp-20]
	
	i = 1 # [rbp-24]
	while(i <= 99):
		j = 1 # [rbp-28]
		while(j <= 99):
			got_final += (got1*i) + (got2*j)
			j+=1
		i+=1

	return got_final



if __name__ == '__main__':
	ret_val = start(7,8)
	print ret_val