asm snippet to pseudo-code

Question

I'm looking into a way to generate pseudo-code from snippet of assembly,

let's assume I have this ASM

    push    rbp
    mov     rbp, rsp
    mov     DWORD PTR [rbp-4], edi
    mov     DWORD PTR [rbp-8], esi
    mov     edx, DWORD PTR [rbp-4]
    mov     eax, DWORD PTR [rbp-8]
    add     eax, edx
    pop     rbp
    ret

is there is a way to turn it into pseudo-code using the available decompilers?

if there is any exported API?

Answer 1

You can take the instructions, assemble them into hex values, for example by using: Online disassembler.

Then you get the byte representation: \x55\x48\x89\xE5\x89\x7D\xFC\x89\x75\xF8\x8B\x55\xFC\x8B\x45\xF8\x01\xD0\x5D\xC3

With this, you can patch bytes in the binary, and then use the normal decompile functionality in Ghidra/Ida on the patched area.

Answer 2

You can actually compile this with NASM depends on your preferred architecture, example command is below (I used linux):

nasm -f elf64 -o ./sample.asm ./sample.o 
ld -o ./sample ./sample.o 


global _start

section .text

_start:

    push    rbp
    mov     rbp, rsp
    mov     DWORD [rbp-4], edi
    mov     DWORD [rbp-8], esi
    mov     edx, DWORD [rbp-4]
    mov     eax, DWORD [rbp-8]
    add     eax, edx
    pop     rbp
    ret

After compiling and linking, I used IDA with pseudo-code support as what @macro_controller mentioned above.

Here is the result.