Candidly

About

Candidly connects to the Screen Sharing that's already built into macOS, so there's nothing to install on the Mac. Sign in with your Mac account, pick a display, and work with touch, a trackpad-style cursor, or a hardware keyboard and mouse. Your computers and their passwords follow you through iCloud.

• Swift 6
• SwiftUI
• UIKit & AppKit
• Metal
• Network framework
• CryptoKit & Security
• iCloud Keychain
• Swift Testing
• XcodeGen

What I built

• The VNC (RFB) protocol written from scratch in Swift, including Apple's Screen Sharing extensions: Mac account sign-in over Diffie-Hellman and RSA, display selection, the shared-or-private session choice and the Mac clipboard. No third-party code.
• ZRLE, Zlib, Hextile and CopyRect decoders hardened against a misbehaving server, with output and size limits, and tested against an in-process fake server and a real VNC server.
• Whole-session encryption with Apple's own Screen Sharing scheme (AES-128 records, on by default after Mac account sign-in), a lock in the viewer, and a per-computer setting that refuses unencrypted sessions.
• A Metal renderer that uploads only the parts of the screen that changed, so a 5K Mac stays smooth on an iPhone.
• Touch and Trackpad modes with the full gesture set: multi-finger clicks and drags, two-finger scroll, pinch zoom, edge and corner swipes, and three-finger swipes for Mission Control and Spaces.
• Saved computers sync through iCloud with merge rules and deletion tombstones, passwords live in iCloud Keychain, and Macs on the network are found with Bonjour.
• The Mac's real pointer, drawn on the device from Apple's cursor-shape messages at three sizes, so it stays sharp and moves without waiting on the network.
• A preview of each computer's last screen in the list, kept on the device only, with a switch in Settings to turn it off.

How it fits together