CODEWITHSUNDEEP
iosswiftkeychain
NSD
NSD

Reputation: 89

How to check if Key was store in KeyChain in Swift

I was trying to store two keys private and public in KeyChain and when I try to do so my result valuable return 0 which I am assuming that mean it was store ,but when I try to get back to decrypt a message I am getting it back as nil so if there is a way to check if the keys were store based SecItemCopyMatching? but I am not getting any error while creating them

let tagName = "PrivateKeyTag"
let privkey = "key"
        let privkeyData = Data(privkey!.utf8)
        let privateFilter: [String : Any] = [
            (kSecClass as String)              : kSecClassKey,
            (kSecAttrKeyType as String)        : kSecAttrKeyTypeRSA,
            (kSecAttrApplicationTag as String) : tagName,
            (kSecValueData as String)          : privkeyData,
            (kSecAttrKeyClass as String)       : kSecAttrKeyClassPrivate,
           // kSecAttrKeySizeInBits as String: 2048,
            (kSecReturnPersistentRef as String): true,

            ] as [String : Any]
        let result = SecItemAdd(privateFilter as CFDictionary, nil)
        if ((result != noErr) && (result != errSecDuplicateItem)) {
            NSLog("Cannot add key to keychain, status \(result).")
        }

let getquery: [String: Any] = [kSecClass as String: kSecClassKey,
                                       kSecAttrApplicationTag as String: tag,
                                       kSecAttrKeyType as String: kSecAttrKeyTypeRSA,
                                       ]
        var item: CFTypeRef?
        let status = SecItemCopyMatching(getquery as CFDictionary, &item)
        guard status == errSecSuccess else {
            print("key not found")
            return
        }
        let key = item as! SecKey

Upvotes: 5

Views: 2452

Answers (1)

Alexander C
Alexander C

Reputation: 686

When you create a cryptographic key, you can set the parameter kSecAttrIsPermanent to true which will automatically store the key in the default keychain. This will clean your code a bit so you no longer have to deal with the SecItemAdd() and all the error handling with that. So here is a simpler way to do what you're trying to do.

To create a key and query a key

let tag = "com.example.keys.mykey".data(using: .utf8)!
let attributes: [String: Any] =
    [kSecAttrKeyType as String:            kSecAttrKeyTypeRSA,
     kSecAttrKeySizeInBits as String:      2048,
     kSecPrivateKeyAttrs as String:
        [kSecAttrIsPermanent as String:    true,
         kSecAttrApplicationTag as String: tag]
]

let privateKey = SecKeyCreateRandomKey(attributes as CFDictionary, nil) 
let query: [String: Any] = [kSecClass as String: kSecClassKey,
                            kSecAttrApplicationTag as String: tag,
                            kSecAttrKeyType as String: kSecAttrKeyTypeRSA,
                            kSecReturnRef as String: true]
var item: CFTypeRef?
let status2 = SecItemCopyMatching(query as CFDictionary, &item)
guard status2 == errSecSuccess else { print("error1"); return }
let key = item as! SecKey

Running this code I believe will accomplish what you are trying to do in the code you provided in the question. I tried running the code you gave and the version of Xcode and swift I am using gives compiler errors.

If you run the code in this answer you will notice that no errors are printed to the console, indicating that the key was successfully found in the default keychain.

Upvotes: 2

Related Questions