Mac OS X was originally presented as the tenth major version of Apple's operating system for Macintosh computers; until 2020, versions of macOS retained the major version number '10'. Previous Macintosh operating systems (versions of the classic Mac OS) were named using Arabic numerals, as. This document is a Mac OS X manual page. Manual pages are a command-line technology for providing documentation. You can view these manual pages locally using the man(1) command. These manual pages come from many different sources, and thus, have a variety of writing styles. ASCII Table is a utility for programmers. I decided to write it because the System 6 style Desk Accessory started crashing under Mac OS 9 and I couldn't find anything that ran natively under Mac OS X. The latest version 1.6.0 has 296 different ASCIImojis built in (see list below). ASCIImoji is currently available in these formats: Mac OS text shortcuts If you use Mac OS, this is your best choice. I need to type the form feed character 0x0C in ASCII on my Mac. Is there any way to do this? I've tried using 'Emoji and Symbols' from the Edit menu, but it's not in there. Macos internationalization. Improve this question. Follow edited Oct 16 '18 at 21:15.
The next step in my playing with chroot escapes is crafting some shellcode. Recently my main dev machine is a MacBook running OS X, so it felt reasonable to fiddle with making system calls of that platform.
By the way, a system call is a function of the kernel invoked by a userspace program and it can be something like writing to a file descriptor, or even exiting. Usually, these are wrapped by C functions in the standard library.
The system calls
First, we need to know what system call we want to make, and what arguments it pretends.
A full list is hosted by Apple here. The header also hints at the fact that they are inherited from BSD. Yeah, that makes sense.
So, to write our proverbial Hello world we will pick the syscall 4
32-bit
Let's start easy. A cute 32-bit program, written in NASM assembler language. Compile with nasm or yasm, output format MachO, and link with ld.
I'm on a Intel machine, so what we are looking for is the x86 syscall calling conventions for the OS X or BSD platform. They are pretty simple:
- arguments passed on the stack, pushed right-to-left
- stack 16-bytes aligned
- syscall number in the
eaxregister - call by interrupt
0x80
So what we have to do to print a 'Hello world' is:
- push the length of the string (
int) to the stack - push a pointer to the string to the stack
- push the stdout file descriptor (1) to the stack
- align the stack by moving the stack pointer 4 more bytes (16 - 4 * 3)
- set the
eaxregister to thewritesyscall number (4) - interrupt
0x80
I'm on a Intel machine, so what we are looking for is the x86 syscall calling conventions for the OS X or BSD platform. They are pretty simple:
- arguments passed on the stack, pushed right-to-left
- stack 16-bytes aligned
- syscall number in the
eaxregister - call by interrupt
0x80
So what we have to do to print a 'Hello world' is:
- push the length of the string (
int) to the stack - push a pointer to the string to the stack
- push the stdout file descriptor (1) to the stack
- align the stack by moving the stack pointer 4 more bytes (16 - 4 * 3)
- set the
eaxregister to thewritesyscall number (4) - interrupt
0x80
64-bit
64-bit is a bit cleaner, but completely different: OS X (and GNU/Linux and everyone except Windows) on 64 architectures adopt the System V AMD64 ABI reference. Jump to section A.2.1 for the syscall calling convention.
Asciipocalypse Mac Os Catalina
- arguments are passed on the registers
rdi,rsi,rdx,r10,r8andr9 - syscall number in the
raxregister - the call is done via the
syscallinstruction - what OS X contributes to the mix is that you have to add
0x20000000to the syscall number (still have to figure out why)
Asciipocalypse Mac Os X
So, here is the (IMHO) much more clean 64-bit 'Hello world'. Ah, if you want to do this at home and have it actually run, generate a macho64 object with a new version of NASM or with YASM, and link with ld as usual.
