Apple does not want to support several web interfaces that give web apps access to device sensors and radio interfaces, thus enabling functions that are otherwise reserved for native apps. The APIs could enable fingerprinting, i.e. the identification of individual devices or users, Apple argues as the reason for the rejection.
Apple refers to data protection
The “1st line of defense” against fingerprinting consists in not implementing web functions that may be problematic from a data protection point of view, announced the WebKit teamthat develops the engine of Apple’s Safari browser. As an example, there is a list of 16 APIs that WebKit has “partially” not implemented due to fingerprinting concerns.
These include Web Bluetooth, Web MIDI API, Magnetometer API, Web NFC API, Device Memory API, Network Information API, Battery Status API, Ambient Light Sensor, HDCP Policy Check extension for EME, Proximity Sensor, WebHID, Serial API, Web USB, Geolocation sensor (location query in the background) and user idle detection, as Apple announced. If precautions are taken against fingerprinting at the interfaces, the decision would be reconsidered.
All iOS browsers with WebKit
The lack of support for the web interfaces also affects third-party browsers such as Chrome and Firefox on iPhones and iPads. Google’s browser supports, for example, Web Bluetooth, which should allow web apps to communicate with Bluetooth LE devices – but not on iOS. Third-party browsers must use Apple’s WebKit engine as a base in iOS and iPadOS.
For some web developers, the disapproval is met with incomprehension and annoyance. Apple chose the “lazy” way to forego the interfaces instead of getting involved in the discussion about securing web standards, complains the web developer Maximiliano Firtman.
Alex Russel, development manager for progressive web apps at Google, sees it as a further step to leave web apps “two-tier” in order not to threaten the app store and the business with native apps. The developer has long accused the company of restraining the web by banning other browser engines.
Apple has already had to defend the browser restriction against US MPs, the group refers to security and data protection. Starting with iOS 14, it should be possible for the first time to set a standard browser on iPhone and iPad – Apple has so far not changed anything about the WebKit specification.