SecItemFromSwift.swift

import Foundation
import Security
    
struct SecItemWrapper {
    static func matching(query: NSDictionary) -> (status: Status, result: AnyObject?) {
        var rawResult: Unmanaged<AnyObject>?
        let rawStatus = SecItemCopyMatching(query, &rawResult)
        let result: AnyObject? = rawResult?.takeRetainedValue()
        let status = Status.fromOSStatus(rawStatus)
        return (status, result)
    }
    
    static func add(attributes: NSDictionary) -> (status: Status, result: AnyObject?) {
        var rawResult: Unmanaged<AnyObject>?
        let rawStatus = SecItemAdd(attributes, &rawResult)
        let result: AnyObject? = rawResult?.takeRetainedValue()
        let status = Status.fromOSStatus(rawStatus)
        return (status, result)
    }
    
    static func update(query: NSDictionary, attributesToUpdate: NSDictionary) -> Status {
        let rawStatus = SecItemUpdate(query, attributesToUpdate)
        return Status.fromOSStatus(rawStatus)
    }
    
    static func delete(query: NSDictionary) -> Status {
        let rawStatus = SecItemDelete(query)
        return Status.fromOSStatus(rawStatus)
    }
    
    enum Status: Int32 {
        // Swift won't allow you to specify a non-literal value below, hence the literal numbers to match errSec*.
        case Success = 0 // errSecSuccess
        case Unimplemented = -4 // errSecUnimplemented
        case Param = -50 // errSecParam
        case Allocate = -108 // errSecAllocate
        case NotAvailable = -25291 // errSecNotAvailable
        case AuthFailed = -25293 // errSecAuthFailed
        case DuplicateItem = -25299 // errSecDuplicateItem
        case ItemNotFound = -25300 // errSecItemNotFound
        case InteractionNotAllowed = -25308 // errSecInteractionNotAllowed
        case Decode = -26275 // errSecDecode
        case Other = -30000
        
        static func fromOSStatus(rawStatus: OSStatus) -> Status {
            return Status(rawValue: rawStatus) ?? .Other
        }
    }
}