Storing Identity in keychain

I'm trying to add .pfx certificate to keychain which comes with password protection. So i decided to get identity from certificate and store it. I'm using system keychain to store identity.And program will run as root.

if let password = CFStringCreateCopy(kCFAllocatorDefault, "something" as CFString) {
        let p12 = SecPKCS12Import(data as CFData, [kSecImportExportPassphrase as String: password] as CFDictionary, &cfarray)
        print(cfarray)
        if let identityArray = cfarray as? NSArray {
            if let identityDict = identityArray.object(at: 0) as? NSDictionary {
                let identityKey = String(kSecImportItemIdentity)
                let identity = identityDict[identityKey] as! SecIdentity
                let query: [String: Any] = [kSecClass as String: kSecClassIdentity,
                                            kSecValueRef as String: identity,
                                            kSecAttrLabel as String: "iddata",
                                            kSecUseKeychain as String: keychain,
                                            kSecImportExportPassphrase as String: password]
                let status = SecItemAdd(query as CFDictionary, nil)
                print(status)
            }
    }
    }

When executing I'm getting -50 as output for print(status).

I also tried with this query dictionary for SecItemAdd

let query: [String: Any] = [kSecClass as String: kSecClassIdentity,kSecValueRef as String: identity,kSecAttrLabel as String: "iddata",kSecUseKeychain as String: keychain,kSecImportExportPassphrase as String: password]

What is wrong with this? Please help