CloudKitClient

This Kotlin library allows you to access your Apple CloudKit public database from your server. This library uses the serverKey authentication.

Stability

This library uses experimental Kotlin libraries, so binary, source and semantic stability cannot be provided!

Supported Server Platforms

• JVM
• nodeJS (currently not available)
• Native (currently not available)

Other Client Platforms

• iOS/macOS/watchOS/tvOS: use the native library from Apple
• Android: use the JS library from Apple
• JS: use the JS library from Apple

Supported Databases

Currently, the public and the private databases are supported.

Key Generation

CloudKit requires an ECDSA keypair with the prime parameter. The public key is uploaded to the iCloud dashboard, which returns the keyID. The private key is used to sign your requests. To generate the private key using the JVM supported PKCS8 format, use the following commands:

openssl ecparam -name prime256v1 -out gen.pem -genkey -noout

openssl pkcs8 -topk8 -in gen.pem -nocrypt -out privateKey.pem

To retrieve the private key use cat privateKey.pem, for the public key use openssl ec -in privateKey.pem -pubout.

Reference

https://developer.apple.com/library/archive/documentation/DataManagement/Conceptual/CloudKitWebServicesReference/index.html#