mobile_nebula/ios/NebulaNetworkExtension/Keychain.swift

import Foundation

let groupName = "group.net.defined.mobileNebula"

class KeyChain {
    class func save(key: String, data: Data, managed: Bool) -> Bool {
        var query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword as String,
            kSecAttrAccount as String: key,
            kSecValueData as String: data,
            kSecAttrAccessGroup as String: groupName,
        ]

        if managed {
            query[kSecAttrAccessible as String] = kSecAttrAccessibleAfterFirstUnlock
        }

        // Attempt to delete an existing key to allow for an overwrite
        _ = delete(key: key)
        return SecItemAdd(query as CFDictionary, nil) == 0
    }

    class func load(key: String) -> Data? {
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrAccount as String: key,
            kSecReturnData as String: kCFBooleanTrue!,
            kSecMatchLimit as String: kSecMatchLimitOne,
            kSecAttrAccessGroup as String: groupName,
        ]

        var dataTypeRef: AnyObject?

        let status: OSStatus = SecItemCopyMatching(query as CFDictionary, &dataTypeRef)

        if status == noErr {
            return dataTypeRef as! Data?
        } else {
            return nil
        }
    }

    class func delete(key: String) -> Bool {
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword as String,
            kSecAttrAccount as String: key,
            kSecAttrAccessGroup as String: groupName,
        ]

        return SecItemDelete(query as CFDictionary) == 0
    }
}

extension Data {
    init<T>(from value: T) {
        var value = value
        var data = Data()
        withUnsafePointer(to: &value) { (ptr: UnsafePointer<T>) in
            data = Data(buffer: UnsafeBufferPointer(start: ptr, count: 1))
        }
        self.init(data)
    }

    func to<T>(type _: T.Type) -> T {
        return withUnsafeBytes { $0.load(as: T.self) }
    }
}