Keychain generic password management in swift 3

Keychain.swift

//
//  Keychain.swift
//  rplcat
//
//  Created by Jeffrey Rafter on 2/6/17.
//  Copyright © 2017 Rplcat. All rights reserved.
//

import Foundation
import Security

class Keychain {
    
    static func set(_ service: String, account: String, data: String) {
        var item: SecKeychainItem? = nil
        
        var status = SecKeychainFindGenericPassword(
            nil,
            UInt32(service.utf8.count),
            service,
            UInt32(account.utf8.count),
            account,
            nil,
            nil,
            &item)
        
        if status != noErr && status != errSecItemNotFound {
            print("Error finding keychain item to modify: \(status), \(SecCopyErrorMessageString(status, nil))")
            return
        }
        
        if item != nil {
            status = SecKeychainItemModifyContent(item!, nil, UInt32(data.utf8.count), data)
        } else {
            status = SecKeychainAddGenericPassword(
                nil,
                UInt32(service.utf8.count),
                service,
                UInt32(account.utf8.count),
                account,
                UInt32(data.utf8.count),
                data,
                nil)
        }

        if status != noErr {
            print("Error setting keychain item: \(SecCopyErrorMessageString(status, nil))")
        }
    }
    
    static func get(_ service: String, account: String) -> String? {
        var passwordLength: UInt32 = 0
        var password: UnsafeMutableRawPointer? = nil
        
        let status = SecKeychainFindGenericPassword(
            nil,
            UInt32(service.utf8.count),
            service,
            UInt32(account.utf8.count),
            account,
            &passwordLength,
            &password,
            nil)
        
        if status == errSecSuccess {
            guard password != nil else { return nil }
            let result = NSString(bytes: password!, length: Int(passwordLength), encoding: String.Encoding.utf8.rawValue) as String?
            SecKeychainItemFreeContent(nil, password)
            return result
        }
        
        return nil
    }

    static func delete(_ service: String, account: String) {
        var item: SecKeychainItem? = nil
        
        var status = SecKeychainFindGenericPassword(
            nil,
            UInt32(service.utf8.count),
            service,
            UInt32(account.utf8.count),
            account,
            nil,
            nil,
            &item)
        
        if status == errSecItemNotFound {
            return
        }
        
        if status != noErr {
            print("Error finding keychain item to delete: \(SecCopyErrorMessageString(status, nil))")
        }
        
        if item != nil {
            status = SecKeychainItemDelete(item!)
        }
        
        if status != noErr {
            print("Error deleting keychain item: \(SecCopyErrorMessageString(status, nil))")
        }
    }
    
}

Sample.swift

import Foundation

func sample() {
   guard let identifier = Bundle.main.bundleIdentifier else { return }
   let service = "\(identifier).oauth-token"
   let account = "jeffrafter"
   Keychain.set(service, account: account, data: "this-is-the-access-token")
   print("The token: \(Keychain.get(service, account: account))")
   Keychain.delete(service, account: account)
}