Tooling around shellcode.
$ # see also https://github.com/ppmx/elfi/tree/master/shellcode
$ python3 opcodes.py -b ../elfi/shellcode/output/hello_world
[+] Analyzing: ../elf/shellcode/output/hello_world
[+] Extracting: _start
[+] Dump of assembler code for function _start:
0x0000000000001038 <+0>: 55 push rbp
0x0000000000001039 <+1>: 48 89 e5 mov rbp,rsp
0x000000000000103c <+4>: 48 b8 48 65 6c 6c 6f 20 77 6f movabs rax,0x6f77206f6c6c6548
0x0000000000001046 <+14>: 48 89 45 da mov QWORD PTR [rbp-0x26],rax
0x000000000000104a <+18>: c7 45 e2 72 6c 64 2e mov DWORD PTR [rbp-0x1e],0x2e646c72
0x0000000000001051 <+25>: 66 c7 45 e6 0a 00 mov WORD PTR [rbp-0x1a],0xa
0x0000000000001057 <+31>: c7 45 fc 01 00 00 00 mov DWORD PTR [rbp-0x4],0x1
0x000000000000105e <+38>: 48 8d 45 da lea rax,[rbp-0x26]
0x0000000000001062 <+42>: 48 89 45 f0 mov QWORD PTR [rbp-0x10],rax
0x0000000000001066 <+46>: c7 45 ec 0e 00 00 00 mov DWORD PTR [rbp-0x14],0xe
0x000000000000106d <+53>: 8b 45 fc mov eax,DWORD PTR [rbp-0x4]
0x0000000000001070 <+56>: 48 98 cdqe
0x0000000000001072 <+58>: 48 89 c7 mov rdi,rax
0x0000000000001075 <+61>: 48 8b 45 f0 mov rax,QWORD PTR [rbp-0x10]
0x0000000000001079 <+65>: 48 89 c6 mov rsi,rax
0x000000000000107c <+68>: 8b 45 ec mov eax,DWORD PTR [rbp-0x14]
0x000000000000107f <+71>: 48 98 cdqe
0x0000000000001081 <+73>: 48 89 c2 mov rdx,rax
0x0000000000001084 <+76>: 48 c7 c0 01 00 00 00 mov rax,0x1
0x000000000000108b <+83>: 0f 05 syscall
0x000000000000108d <+85>: 89 c0 mov eax,eax
0x000000000000108f <+87>: 89 45 e8 mov DWORD PTR [rbp-0x18],eax
0x0000000000001092 <+90>: 48 31 ff xor rdi,rdi
0x0000000000001095 <+93>: 48 c7 c0 3c 00 00 00 mov rax,0x3c
0x000000000000109c <+100>: 0f 05 syscall
0x000000000000109e <+102>: eb f2 jmp 0x1092 <_start+90>
[+] Opcodes from function '_start' of binary '../elf/shellcode/output/hello_world'
554889e548b848656c6c6f20776f488945dac745e2726c642e66c745e60a00c745fc01000000488d45da488945f0c745ec0e0000008b45fc48984889c7488b45f04889c68b45ec48984889c248c7c0010000000f0589c08945e84831ff48c7c03c0000000f05ebf2
This extracted code can also be stored inside a file using the -o flag.
The shellcode executor tool is then useful to test this extracted shellcode.