class func save(service: NSString, data: NSString) {
  var dataFromString: NSData = data.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)
  // Instantiate a new default keychain query
  var keychainQuery: NSMutableDictionary = NSMutableDictionary(objects: [kSecClassGenericPassword, service, userAccount, dataFromString], forKeys: [kSecClass, kSecAttrService, kSecAttrAccount, kSecValueData])

  // Delete any existing items
  SecItemDelete(keychainQuery as CFDictionaryRef)

  // Add the new keychain item
  var status: OSStatus = SecItemAdd(keychainQuery as CFDictionaryRef, nil)

  // Check that it worked ok
  println("Saving status code is: (status)")
}

class func load(service: NSString) -> AnyObject? {
    // Instantiate a new default keychain query
    // Tell the query to return a result
    // Limit our results to one item
    var keychainQuery: NSMutableDictionary = NSMutableDictionary(objects: [kSecClassGenericPassword, service, userAccount, kCFBooleanTrue, kSecMatchLimitOne], forKeys: [kSecClass, kSecAttrService, kSecAttrAccount, kSecReturnData, kSecMatchLimit])



    // I'm not too sure what's happening here...
    var dataTypeRef :Unmanaged<AnyObject>?

    // Search for the keychain items
    let status: OSStatus = SecItemCopyMatching(keychainQuery, &dataTypeRef)


    println("Loading status code is: (status)")

    // I'm not too sure what's happening here...
    let opaque = dataTypeRef?.toOpaque()

    if let op = opaque? {
      let retrievedData = Unmanaged<NSData>.fromOpaque(op).takeUnretainedValue()
      println("Retrieved the following data from the keychain: (retrievedData)")
      var str = NSString(data: retrievedData, encoding: NSUTF8StringEncoding)
      println("The decoded string is (str)")
    } else {
      println("Nothing was retrieved from the keychain.")
    }

    return nil
  }

KeychainService.saveToken("sometoken")
KeychainService.loadToken()

class func saveToken(token: NSString) {
    self.save("service", data: token)
  }

class func loadToken() {
    var token = self.load("service")
    if let t = token {
      println("The token is: (t)")
    }
  }

Saving status code is: 0
Loading status code is: 0
Retrieved the following data from the keychain: <736f6d65 746f6b65 6e>
The decoded string is sometoken

let kSecClassValue = kSecClass.takeRetainedValue() as NSString
let kSecAttrAccountValue = kSecAttrAccount.takeRetainedValue() as NSString
let kSecValueDataValue = kSecValueData.takeRetainedValue() as NSString
let kSecClassGenericPasswordValue = kSecClassGenericPassword.takeRetainedValue() as NSString
let kSecAttrServiceValue = kSecAttrService.takeRetainedValue() as NSString
let kSecMatchLimitValue = kSecMatchLimit.takeRetainedValue() as NSString
let kSecReturnDataValue = kSecReturnData.takeRetainedValue() as NSString
let kSecMatchLimitOneValue = kSecMatchLimitOne.takeRetainedValue() as NSString

var keychainQuery: NSMutableDictionary = NSMutableDictionary(objects: [kSecClassGenericPasswordValue, service, userAccount, kCFBooleanTrue, kSecMatchLimitOneValue], forKeys: [kSecClassValue, kSecAttrServiceValue, kSecAttrAccountValue, kSecReturnDataValue, kSecMatchLimitValue])

let keychain = KeychainSwift()
keychain.set("hello world", forKey: "my key")
keychain.get("my key")
keychain.delete("my key")

let saveSuccessful: Bool = KeychainWrapper.setString("Some String", forKey: "myKey")

let retrievedString: String? = KeychainWrapper.stringForKey("myKey")

let removeSuccessful: Bool = KeychainWrapper.removeObjectForKey("myKey")

// Saving password associated with the login and service
let userAccount = "user's login"
let service = "service name"
let passwordData: NSData = self.textfield_password.text!.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!

let keychainQuery: [NSString: NSObject] = [
        kSecClass: kSecClassGenericPassword,
        kSecAttrAccount: userAccount,
        kSecAttrService: service,
        kSecValueData: passwordData]

SecItemDelete(keychainQuery as CFDictionaryRef) //Deletes the item just in case it already exists
let keychain_save_status: OSStatus = SecItemAdd(keychainQuery as CFDictionaryRef, nil)
print("Keychain saving code is: (keychain_save_status)")

...

// Getting the password associated with the login and service
let userAccount = "user's login"
let service = "service name"
let keychainQuery: [NSString: NSObject] = [
    kSecClass: kSecClassGenericPassword,
    kSecAttrService: service,
    kSecAttrAccount: userAccount,
    kSecReturnData: kCFBooleanTrue,
    kSecMatchLimit: kSecMatchLimitOne]

var rawResult: AnyObject?
let keychain_get_status: OSStatus = SecItemCopyMatching(keychainQuery, &rawResult)
print("Keychain getting code is: (keychain_get_status)")

if (keychain_get_status == errSecSuccess) {
    let retrievedData = rawResult as? NSData
    let pass = NSString(data: retrievedData!, encoding: NSUTF8StringEncoding)
    print("Username: (userAccount), password: (pass!)")
    // Do your work with the retrieved password here
} else {
    print("No login data found in Keychain.")

...

//Deleting user's credentials from Keychain. Password is optional for the query when you delete, in most cases you won't know it after all.
let userAccount = "user's login"
let service = "service name"

let keychainQuery: [NSString: NSObject] = [
        kSecClass: kSecClassGenericPassword,
        kSecAttrAccount: userAccount,
        kSecAttrService: service]
let keychain_delete_status: OSStatus = SecItemDelete(keychainQuery as CFDictionaryRef)
print("Keychain deleting code is: (keychain_delete_status)")

class func save(service: NSString, data: NSString) {
  var dataFromString: NSData = data.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)
  // Instantiate a new default keychain query
  var keychainQuery: NSMutableDictionary = NSMutableDictionary(objects: [kSecClassGenericPassword, service, userAccount, dataFromString], forKeys: [kSecClass, kSecAttrService, kSecAttrAccount, kSecValueData])

  // Delete any existing items
  SecItemDelete(keychainQuery as CFDictionaryRef)

  // Add the new keychain item
  var status: OSStatus = SecItemAdd(keychainQuery as CFDictionaryRef, nil)

  // Check that it worked ok
  println("Saving status code is: (status)")
}

class func load(service: NSString) -> AnyObject? {
    // Instantiate a new default keychain query
    // Tell the query to return a result
    // Limit our results to one item
    var keychainQuery: NSMutableDictionary = NSMutableDictionary(objects: [kSecClassGenericPassword, service, userAccount, kCFBooleanTrue, kSecMatchLimitOne], forKeys: [kSecClass, kSecAttrService, kSecAttrAccount, kSecReturnData, kSecMatchLimit])



    // I'm not too sure what's happening here...
    var dataTypeRef :Unmanaged<AnyObject>?

    // Search for the keychain items
    let status: OSStatus = SecItemCopyMatching(keychainQuery, &dataTypeRef)


    println("Loading status code is: (status)")

    // I'm not too sure what's happening here...
    let opaque = dataTypeRef?.toOpaque()

    if let op = opaque? {
      let retrievedData = Unmanaged<NSData>.fromOpaque(op).takeUnretainedValue()
      println("Retrieved the following data from the keychain: (retrievedData)")
      var str = NSString(data: retrievedData, encoding: NSUTF8StringEncoding)
      println("The decoded string is (str)")
    } else {
      println("Nothing was retrieved from the keychain.")
    }

    return nil
  }

KeychainService.saveToken("sometoken")
KeychainService.loadToken()

class func saveToken(token: NSString) {
    self.save("service", data: token)
  }

class func loadToken() {
    var token = self.load("service")
    if let t = token {
      println("The token is: (t)")
    }
  }

Saving status code is: 0
Loading status code is: 0
Retrieved the following data from the keychain: <736f6d65 746f6b65 6e>
The decoded string is sometoken