Using Keychain Services in Swift 2

Your code shown above contains a workaround needed till Swift 1.1. (Seems to work in Swift 1.2 or 2, but not recommended.)

Here's a code I use in Swift 1.2 (works in Swift 2, I believe), though, I'm not sure you find this cleaner.

        let keychainQuery: [NSObject: AnyObject] =  [
            kSecClass : kSecClassGenericPassword,
            kSecAttrService : serviceName,
            kSecAttrAccount : userAccount,
            kSecReturnData : kCFBooleanTrue,
            kSecMatchLimit : kSecMatchLimitOne]
   
        var dataTypeRef: Unmanaged<AnyObject>?
        let status = SecItemCopyMatching(keychainQuery, &dataTypeRef)
        if status == errSecSuccess,
            let retrievedData = dataTypeRef?.takeRetainedValue() as! NSData? {
            //process retrivedData
        } else {
            //process error
        }

UPDATE for Swift 2.2 (or update was needed for former versions...)

I believe this compiles and works in Swift 2.2:

        let keychainQuery: [NSObject: AnyObject] =  [
            kSecClass : kSecClassGenericPassword,
            kSecAttrService : serviceName,
            kSecAttrAccount : userAccount,
            kSecReturnData : kCFBooleanTrue,
            kSecMatchLimit : kSecMatchLimitOne]
     
        var dataTypeRef: AnyObject?
        let status = SecItemCopyMatching(keychainQuery, &dataTypeRef)
        if status == errSecSuccess,
            let retrievedData = dataTypeRef as! NSData? {
            //process retrivedData
        } else {
            //process error
        }

Actually, that makes quite a lot of sense. I just would never have figured out the connection between '&' and 'UnsafeMutablePointer<…>' (which is the type of the second parameter) without someone pointing it out.

I wrote a blog post about keychain + swift 2 here: http://www.splinter.com.au/2015/06/21/swift-keychain-wrapper/

It takes advantage of the new 'throws' ability, i think it's worth a read.

I know it's been awhile, but it looks like this code

        var dataTypeRef: Unmanaged<AnyObject>?
        var status = SecItemCopyMatching(query, &dataTypeRef)

doesn't compile in swift 2.2. It says "Cannot convert value of type 'Unmanaged<AnyObject>? to expected argument type 'AnyObject?' For that reason I'm going to go with the strange way below:

  let status = withUnsafeMutablePointer (&result) { SecItemCopyMatching (query, UnsafeMutablePointer ($0)) }

Added an updated code for Swift 2.2.

`SecItemCopyMatching(_:_:)` has changed its signature to:

SecItemCopyMatching(query: CFDictionary, _ result: UnsafeMutablePointer<AnyObject?>) -> OSStatus

So you can write the core part as:

        var dataTypeRef: AnyObject?
        let status = SecItemCopyMatching(keychainQuery, &dataTypeRef)

Do you need an updated code for Swift 3?

It doesn't look like this code works with Swift 3 anymore, you receive a compilation error that you need to use withMemoryRebound() now. Does anyone know the proper way to call this in Swift 3? I've been playing with the syntax but I haven't been able to come up with it yet. This is as far as I've gotten, but I receive an error "Cannot convert value of type 'UnsafeMutablePointer<_>' to expected argument type 'UnsafeMutablePointer<CFTypeRef?>?'

_ = withUnsafeMutablePointer(to: &result) {

$0.withMemoryRebound(to: CFTypeRef.self, capacity: 1, {

SecItemCopyMatching(searchDictionary, $0)

})

}

The signature of `SecItemCopyMatching` has not much changed in Swift 3:

func SecItemCopyMatching(CFDictionary, UnsafeMutablePointer<CFTypeRef?>?)

func SecItemCopyMatching(_ query: CFDictionary,
                         _ result: UnsafeMutablePointer<CFTypeRef?>?) -> OSStatus

And `CFTypeRef` is a typealias of `AnyObject`.

So, this works in Swift 3:

        var dataTypeRef: CFTypeRef?
        let status = SecItemCopyMatching(keychainQuery as CFDictionary, &dataTypeRef)

Some parts depend on how you declared `searchDictionary` and `result`, but you usally have no need to use `withUnsafeSomething`.