Keith Smiley keith

macOS Internals

Understand your Mac and iPhone more deeply by tracing the evolution of Mac OS X from prelease to Swift. John Siracusa delivers the details.

Starting Points

How to use this gist

You've got two main options:

theme

class

highlighter

fonts

default

text-center

MaskRay

sans	serif	mono
sans-serif	serif	monospace

ELF Format Cheatsheet

Introduction

Executable and Linkable Format (ELF), is the default binary format on Linux-based systems.

Compilation

Updating expired GPG keys and their backup 🔑🔐💻

I use a GPG key to sign my git commits.

An error like this one might be a sign of an expired GPG key.

error: gpg failed to sign the data fatal: failed to write commit object

Debugging the Swift Toolchain

Use these steps to debug components of the Swift toolchain. This allows you to see Swift's source code from the debugger – instead of disassembly. The debugger can also provide some variable names and values. This has been initially tested with libswiftCore.dylib.

These instructions were updated as of Swift 5.2.1.

Prerequisites

Renew GPG key

Given that your key has expired.

$ gpg --list-keys
$ gpg --edit-key KEYID

Use the expire command to set a new expire date:

iOS app introspection

Jailbreak in 2025
Create Provisioning Profile in XCode

	from os import urandom
	from socket import create_connection

	from cryptography.hazmat.primitives.asymmetric import padding
	from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
	from cryptography.hazmat.primitives.serialization import load_der_public_key


	def read(sock, length):
	result = b''

	// Example usage:
	// Swizzler<NSString , NSDateFormatter , NSDate *> NSDateFormatter_stringFromDate_ {
	// NSDateFormatter.class, @selector(stringFromDate:), [&](auto self, auto date) {
	// if ([NSCalendar.currentCalendar components:NSCalendarUnitWeekday fromDate:date].weekday == 4) {
	// return @"It Is Wednesday My Dudes";
	// } else {
	// return NSDateFormatter_stringFromDate_(self, date);
	// }
	// }
	// };

	wget --no-check-certificate --recursive --domains=opensource.apple.com --no-clobber --accept "*.gz" --no-parent -l2 https://opensource.apple.com/tarballs
	wget --no-check-certificate --recursive --domains=opensource.apple.com --no-clobber --accept "*.gz" -l2 https://opensource.apple.com/
	wget --no-check-certificate --recursive --domains=opensource.apple.com --no-clobber --accept "*.gz" --no-parent -l3 https://opensource.apple.com/darwinbuild/