KlugKeychain

Overview

KlugKeychain stores small values, such as flags, tokens or IDs, in the keychain of iOS and macOS. Unlike normal app storage, the keychain keeps these values when the app is uninstalled and installed again.

That makes it a durable anchor for things an app needs to remember across reinstalls, for example whether a device has already used a free trial, or whether an account was deleted before.

KlugKeychain is in daily use in our apps, our proof of concept.

Features

• Self-contained: one ANE, no core library or dependency ANEs to add
• Store, read, check and remove values by key
• Values survive uninstalling and reinstalling the app
• Encrypted by the operating system in the system keychain
• One API for iOS and macOS
• Simple synchronous calls, no events to handle

Supported platforms

On other platforms isSupported returns false, so the same code can stay in a cross-platform app.

Getting started

Add the extension to your application descriptor:

<extensions>
    <extensionID>com.klug.keychain.Keychain</extensionID>
</extensions>

On macOS the app must be signed with a keychain access group entitlement. On iOS no extra entitlement is needed.

Code examples

Three complete flows. All calls are synchronous and return at once; values are strings. Full documentation →

import com.klug.keychain.Keychain;

var keychain:Keychain = Keychain.getInstance();

// iOS: always true.
// macOS: true only if the app is signed with a keychain access group entitlement;
//        the extension checks this with a test write.
// Android, Windows: false, and every call is a safe no-op.
if ( !keychain.isSupported )
    useLocalStorage();   // your app's fallback, e.g. a SharedObject

const TRIAL_DAYS:Number = 7;

if ( keychain.has( "trialStarted" ) )
{
    var started:Number = Number( keychain.get( "trialStarted" ) );
    var days:Number = ( new Date().time - started ) / 86400000;
    if ( days > TRIAL_DAYS ) showPurchaseScreen();   // your app
}
else
{
    // stays in the keychain after the app is uninstalled and installed again
    keychain.set( "trialStarted", String( new Date().time ) );
}

// set() replaces an existing value; false = not stored
if ( !keychain.set( "accountId", accountId ) )
    trace( "keychain: value not stored" );

// get() returns "" when nothing is stored
var id:String = keychain.get( "accountId" );
if ( id == "" ) showSignIn();   // your app

// sign-out: remove what the app no longer needs;
// true also when the key was already gone
keychain.remove( "accountId" );

API overview

Buy KlugKeychain

A yearly licence for one AIR application, with all updates for 12 months. After payment you receive the extension, the ActionScript library and the documentation by e-mail, usually within one business day. Licence and terms

Requirements