Added assembly-2

Author: PlatyPew

Reversing/assembly-2/README.md

@@ -11,19 +11,54 @@ Reversing
 >assembly [conditions](https://www.tutorialspoint.com/assembly_programming/assembly_conditions.htm)
 
 ## Solution
+Compile the asm together with another function that calls the _asm2_ function and prints it out
+
 ```asm
-; [ebp + 0xc] = 0x28
-; [ebp + 0x8] = 0x7
+[0x000011f4]> pdf
+/ (fcn) loc.asm2 44
+|   loc.asm2 (int arg_8h, int arg_ch);
+|           ; var int local_8h @ ebp-0x8
+|           ; var int local_4h @ ebp-0x4
+|           ; arg int arg_8h @ ebp+0x8
+|           ; arg int arg_ch @ ebp+0xc
+|           ; CALL XREF from sym.main (0x11ca)
+|           0x000011f4      55             push ebp
+|           0x000011f5      89e5           mov ebp, esp
+|           0x000011f7      83ec10         sub esp, 0x10
+|           0x000011fa      8b450c         mov eax, dword [arg_ch]     ; [0xc:4]=0
+|           0x000011fd      8945fc         mov dword [local_4h], eax
+|           0x00001200      8b4508         mov eax, dword [arg_8h]     ; [0x8:4]=0
+|           0x00001203      8945f8         mov dword [local_8h], eax
+|       ,=< 0x00001206      eb08           jmp loc.part_b
+|       |   ;-- part_a:
+|      .--> 0x00001208      8345fc01       add dword [local_4h], 1
+|      :|   0x0000120c      83450876       add dword [arg_8h], 0x76    ; 'v'
+|      :|   ;-- part_b:
+|      :|   ; CODE XREF from loc.asm2 (0x1206)
+|      :`-> 0x00001210      817d08dea100.  cmp dword [arg_8h], 0xa1de  ; [0xa1de:4]=-1
+|      `==< 0x00001217      7eef           jle loc.part_a
+|           0x00001219      8b45fc         mov eax, dword [local_4h]
+|           0x0000121c      89ec           mov esp, ebp
+|           0x0000121e      5d             pop ebp
+\           0x0000121f      c3             ret
+```
 
-; [ebp - 0x4] = 0x28
-; [ebp-0x8] = 0x7
+```
+$ make all
+gcc -m32 -c loop.s -o loop.o
+gcc -m32 -c solve.c -o solve.o
+solve.c: In function ‘main’:
+solve.c:4:28: warning: implicit declaration of function ‘asm2’ [-Wimplicit-function-declaration]
+     printf("Flag: 0x%x\n", asm2(0x7, 0x28));
+                            ^~~~
+gcc -m32 -o a.out solve.o loop.o
+./a.out
+Flag: 0x188
+```
 
-; 0x7 < 0a1de
-; [ebp - 0x4] = 0x29
-; [ebp + 0x8] = 0x7d
+Working solution [solve.sh](solution/solve.sh)
 
-; eax = 0x29
-```
+Thanks to [@LFlare](https://github.com/LFlare) for basically solving this.
 
 ### Flag
-``
+`0x188`

Reversing/assembly-2/solution/Makefile

@@ -0,0 +1,7 @@
+all:
+	gcc -m32 -c loop.s -o loop.o
+	gcc -m32 -c solve.c -o solve.o
+	gcc -m32 -o a.out solve.o loop.o
+	./a.out
+clean:
+	rm a.out *.o

Reversing/assembly-2/solution/loop.s

@@ -0,0 +1,23 @@
+.intel_syntax noprefix
+	
+.global asm2
+
+asm2:
+	push   	ebp
+	mov    	ebp,esp
+	sub    	esp,0x10
+	mov    	eax,DWORD PTR [ebp+0xc]
+	mov 	DWORD PTR [ebp-0x4],eax
+	mov    	eax,DWORD PTR [ebp+0x8]
+	mov	DWORD PTR [ebp-0x8],eax
+	jmp    	part_b
+part_a:	
+	add    	DWORD PTR [ebp-0x4],0x1
+	add	DWORD PTR [ebp+0x8],0x76
+part_b:	
+	cmp    	DWORD PTR [ebp+0x8],0xa1de
+	jle    	part_a
+	mov    	eax,DWORD PTR [ebp-0x4]
+	mov	esp,ebp
+	pop	ebp
+	ret

Reversing/assembly-2/solution/solve.c

@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+int main() {
+    printf("Flag: 0x%x\n", asm2(0x7, 0x28));
+}

Reversing/assembly-2/solution/solve.sh

@@ -0,0 +1,2 @@
+#!/bin/sh
+make all