I'm trying to set up server-to-server authentication with CloudKit Web Services, but keep getting AUTHENTICATION_FAILED errors. I've tried multiple environment settings and debugging approaches without success.
What I've Tried
I created a Swift script to test the connection. Here's the key part that handles the authentication:
// Get current ISO 8601 date
let iso8601Formatter = ISO8601DateFormatter()
iso8601Formatter.formatOptions = [.withInternetDateTime]
let dateString = iso8601Formatter.string(from: Date())
// Create SHA-256 hash of request body
let bodyHash = SHA256.hash(data: bodyData).compactMap { String(format: "%02x", $0) }.joined()
// Get path from URL
let path = request.url?.path ?? "/"
// String to sign
let method = request.httpMethod ?? "POST"
let stringToSign = "\(method):\(path):\(dateString):\(bodyHash)"
// Sign the string with EC private key
let signature = try createSignature(stringToSign: stringToSign)
// Add headers
request.setValue(dateString, forHTTPHeaderField: "X-Apple-CloudKit-Request-ISO8601Date")
request.setValue(KEY_ID, forHTTPHeaderField: "X-Apple-CloudKit-Request-KeyID")
request.setValue(signature, forHTTPHeaderField: "X-Apple-CloudKit-Request-SignatureV1")
}
I've made a request to this endpoint:
What's Happening
I get a 401 status with this response:
"uuid" : "173179e2-c5a5-4393-ab4f-3cec194edd1c",
"serverErrorCode" : "AUTHENTICATION_FAILED",
"reason" : "Authentication failed"
}
What I've Verified
The key validates correctly and generates signatures
The date/time is synchronized with the server
The key ID matches what's in CloudKit Dashboard
I've tried all three environments: development, Development (capital D), and production
The container ID is formatted correctly
Debug Information
My debugging reveals:
The EC key is properly formatted (SEC1 format)
Signature generation works
No time synchronization issues between client and server
All environment tests return the same 401 error
Questions
Has anyone encountered similar issues with CloudKit server-to-server authentication?
Are there specific container permissions needed for server-to-server keys?
Could there be an issue with how the private key is formatted or processed?
Are there any known issues with the CloudKit Web Services API that might cause this?
Any help would be greatly appreciated!
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
Cloud and Local Storage
CloudKit JS