osx macOS public key import to keychain duplicate - swift

Question

I am trying to permanently import an RSA public key into the keychain
let params: [NSString: AnyObject] = [
kSecClass: kSecClassKey,
kSecAttrKeyType: kSecAttrKeyTypeRSA,
kSecAttrApplicationTag: tag as AnyObject,
kSecValueData: data as AnyObject,
kSecReturnPersistentRef: true as AnyObject
]
let persistKey = UnsafeMutablePointer<AnyObject?>(mutating: nil)
let status = SecItemAdd(params as CFDictionary, persistKey)
....
Unfortunately the key (regardless which) gets errSecDuplicateItem but if I select it with SecItemCopyMatching.... i get errSecItemNotFound
I tried multiple solutions like adding different attributes like account etc.. but most of this eventually resulted in unknown parameter errors.
I'm sure the key is correct cause SecKeyCreateWithData is fine with it.
edit:
Thats the way to collect the key:
let params: [NSString: AnyObject] = [
kSecClass: kSecClassKey,
kSecAttrKeyType: kSecAttrKeyTypeRSA,
kSecAttrApplicationTag: tag as AnyObject,
kSecReturnRef: true as AnyObject
]
var keyRef: AnyObject? = nil
status = SecItemCopyMatching(params, &keyRef)
The key is also not findable if you look it up manually in the keychain app

Answer 1

I had the same issue. The code worked fine for me on iOS but I could not get it to work for macOS either.
I then rewrote the code by using Apple's documentation https://developer.apple.com/documentation/security/certificate_key_and_trust_services/keys/storing_keys_as_data
So the code to get a SecKeyRef from a public key given as Data is just:
let options: [String: Any] = [kSecAttrKeyType as String: kSecAttrKeyTypeRSA,
kSecAttrKeyClass as String: kSecAttrKeyClassPublic,
kSecAttrKeySizeInBits as String : 2048]
var error: Unmanaged<CFError>?
guard let key = SecKeyCreateWithData(data as CFData,
options as CFDictionary,
&error) else {
throw error!.takeRetainedValue() as Error
}