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Darwin tooling

Leptos leptos-null

Darwin tooling
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leptos-null / llvm.nanorc
Last active Jan 21, 2022
LLVM syntax highlighting for nano
View llvm.nanorc
## LLVM syntax highlighting for nano by Leptos
## Based off the official nano C/C++ template
syntax ll "\.ll$"
magic "LLVM source"
comment ";"
# all numeral literals
color brightcyan "-?[0-9]*"
leptos-null /
Last active Jan 14, 2022
Using cycript on macOS Mojave

Cycript on Mojave

Cycript is a tool I find very helpful. It's an effective REPL for Objective-C. When I updated to macOS Mojave, I found that cycript no longer worked because it was linked against an old version of Ruby. After attempting to compile from source, I tried another solution. install_name_tool is an open source tool for modifying the names of linked shared libraries in a Mach-O.


$ install_name_tool -change /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/libruby.2.0.0.dylib /System/Library/Frameworks/Ruby.framework/Versions/Current/usr/lib/libruby.dylib Cycript.lib/cycript-apl
$ install_name_tool -change /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/libruby.2.0.0.dylib /System/Library/Frameworks/Ruby.framework/Versions/Current/usr/lib/libruby.dylib Cycript.lib/libcycript.dylib
leptos-null /
Last active Sep 14, 2021
Writing an iOS YouTube Music client

Writing an iOS YouTube Music client

I’ve been using YouTube Music as my main music streaming service for almost a year and a half. The iOS client is great- I’ve never had a single complaint. It’s potentially one of the most bug free apps I’ve ever used, it has an extremely friendly, and simple, graphical interface, and the service itself is great.

I was curious how the client worked in terms of networking, and while curiosity may treat cats poorly, it lands researchers in black sites can provide a lot of insight.

Step 0

The first thing I do when reverse engineering a client is monitor HTTP requests while the application starts up, and when doing the tasks interested in. On a jailbroken iOS device, I use FLEX by FlipBoard.

leptos-null / LMApiaryDeviceCrypto.h
Last active Jul 20, 2021
Fully implemented mirror of YouTube's YTApiaryDeviceCrypto class
View LMApiaryDeviceCrypto.h
// LMApiaryDeviceCrypto.h
// Created by Leptos on 11/18/18.
// Copyright © 2018 Leptos. All rights reserved.
#import <Foundation/Foundation.h>
#define kYouTubeBase64EncodedProjectKey @"vOU14u6GkupSL2pLKI/B7L3pBZJpI8W92RoKHJOu3PY="
leptos-null /
Last active Apr 29, 2021
Mojave Dynamic Desktop- How it works

Mojave Dynamic Desktop- How it works

Prompted by a tweet by NSHipster, and a subsequent thread, I wanted to find out how Mojave dynamic wallpapers worked. NSHipster and ole reverse engineered the file format. In the Twitter thread, NSHipster mentions an edge case: What happens above 66ºN (latitude)?

The first thing to do was find out what process handles the wallpaper on macOS. I primarily do iOS research, and honestly had no idea. I opened Console, searched for "solar", and then changed my static wallpaper to a dynamic one. Voila!

Message: index: 7 next: 14815.999366

Process: Dock

leptos-null / UIImageUnicode.m
Last active Oct 19, 2020
Draw UIImage of Unicode character
View UIImageUnicode.m
@implementation UIImage (UIImageUnicode)
+ (UIImage *)imageFromUnicodePoint:(unichar)codepoint compatibleWithTraitCollection:(UITraitCollection *)traitCollection API_AVAILABLE(ios(10.0)) {
NSString *str = [NSString stringWithCharacters:&codepoint length:1];
UIFont *weightRef = [UIFont preferredFontForTextStyle:UIFontTextStyleBody compatibleWithTraitCollection:traitCollection];
UIFont *sizeRef = [UIFont preferredFontForTextStyle:UIFontTextStyleTitle2 compatibleWithTraitCollection:traitCollection];
NSAttributedString *drawReady = [[NSAttributedString alloc] initWithString:str attributes:@{
NSFontAttributeName : [weightRef fontWithSize:sizeRef.pointSize]
UIGraphicsBeginImageContextWithOptions([drawReady size], NO, 0);
leptos-null / ios_image_app_url_dump.m
Last active Apr 19, 2020
Dump URL schemes from an iOS system image (stock applications)
View ios_image_app_url_dump.m
// ios_image_app_url_dump
// Created by Leptos on 2/19/19.
// Copyright © 2019 Leptos. All rights reserved.
/* compile with:
* $ clang -fobjc-arc -framework Foundation
leptos-null /
Created Apr 12, 2020
Red Cross Blood REST API Reference

Red Cross Blood REST API Reference

This guide is based on research from version 1.7.3 of Red Cross Blood iOS app.


This reference is for version 2.1 of the interface.


leptos-null / open_app.m
Created Aug 28, 2019
[iOS] Open an application from the command line by bundle identifier
View open_app.m
@import Foundation;
@import MobileCoreServices;
@interface LSApplicationWorkspace : NSObject
+ (instancetype)defaultWorkspace;
- (BOOL)openApplicationWithBundleID:(NSString *)bundleID API_AVAILABLE(ios(7.0));
leptos-null /
Last active Dec 23, 2019
How to scale temperature and other measurements

Temperature Scaling

What’s it mean if the temperature is going to be 30% warmer or 30% cooler?

Distance Scaling

Let’s take something that we know works: distances. If I have a distance that’s 2 meters, 30% more is (x=2, s=0.3; x*(1+s)) 2.6 meters, and 30% less is (x=2, s=-0.3; x*(1+s)) 1.4 meters. Covert these three values to feet, you get 6.56, 8.53, and 4.59 respectively. If we plug these numbers back into our scaling equation: more is (x=6.56, s=0.3; x*(1+s)) 8.528 feet, and less is (x=6.56, s=-0.3; x*(1+s)) 4.592 feet. These values are slightly off due to rounding.

Fixing Temperature

The problem with temperature is that it’s not zero-based. A value some incremental amount warmer than 5 degrees Fahrenheit is still cold. We need to “normalize” temperature. To do that, we have to find a value such that anything warmer feels warmer, and anything cooler feels cooler. We’re going to use 22°C (72°F) for this value.