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Showing posts from June, 2022

code signing, entitlements, bundles, sandboxes, hardened runtime, notarisation, app store security

Some people had mentioned troubles with code signing, i thought a brain dump of my learnings on it might be informative and helpful as I've learned a lot in developing a mac app (the s4a IDE).  Some of these concepts are used in ios too but this post is about mac apps. First up, terminology. Code signing. *** This is a variant of normal PKI (public key infrastructure) signing. A hash is made of the binary you're signing (the actual macho executable file), then encrypted with your private key to make a signature that anyone with your public key can decrypt and verify to check your binary hasn't been altered in any way since you signed it. Code signing could in theory be done with any tool, (many of these concepts are NOT mac/ios only concepts but follow general unix/windows/etc. principles and ideas widely used across industry), but in reality, people on a mac use the built in (to macOS) tool "codesign" which is a command line tool that can create, alter, remove an

Comparing iLEDs

This might seem a bit off topic, but i've never seen the need for this blog to only be about S4A. :) There are a bunch of RGB LEDs out there that are controlled by a one wire protocol (note: readers, feel free to add any info in the comments section or links to similar comparison blog posts, let's help each other out!) Most of them are made by world semi, hence the WS part numbers. Here are some comparison links: https://www.utmel.com/components/ws2811-vs-ws2812b?id=614 https://www.pololu.com/category/180/sk6812-ws2812b-based-led-strips https://cdn.sparkfun.com/assets/learn_tutorials/1/0/5/WS2812B_VS_WS2812.pdf https://www.suntechleds.com/info/ws2813-vs-ws2815-digital-programmablel-led-str-36642316.html needless to say any of the relatively small family of core ileds are then resold by a variety of manufacturers in a variety of form factors, but fundamentally the code needed to control them is the same for each family (note, I'm not talking about other chips that are contro