Reversing 150: assembly-0

Challenge

What does asm0(0xd8,0x7a) return? Submit the flag as a hexadecimal value (starting with 0x).

NOTE: Your submission for this question will NOT be in the normal flag format. Source
located in the directory at /problems/assembly-0_1_fc43dbf0079fd5aab87236bf3bf4ac63.

Solution

.intel_syntax noprefix
.bits 32

.global asm0

asm0:
	push	ebp
	mov	ebp,esp
	mov	eax,DWORD PTR [ebp+0x8]
	mov	ebx,DWORD PTR [ebp+0xc]
	mov	eax,ebx
	mov	esp,ebp
	pop	ebp
	ret

we can deduce the output manually. ret will return the value of eax, which was set to the value of ebx (mov eax ebx), and ebx was set do the second argument we passed to the program (mov ebx,DWORD PTR [ebp+0xc]), which in this case was 0x7a

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