SsidBssid.swift

import UIKit
import SystemConfiguration.CaptiveNetwork

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        print("SSID: \(currentID(for: kCNNetworkInfoKeySSID))\nBSSID: \(currentID(for: kCNNetworkInfoKeyBSSID))")
    }

}

extension ViewController {

    // kCNNetworkInfoKeySSID    NetworkInfo Dictionary key for SSID in CFString format
    // kCNNetworkInfoKeyBSSID   NetworkInfo Dictionary key for BSSID in CFString format
    
    /// Get the current SSID or BSSID, if connected to Wi-FI, otherwise return "N/A" string
    func currentID(for networkInfoDictionaryKey: CFString) -> String {
        
        enum SupportedInterfacesQueryResult: String, CustomStringConvertible {
            case notAvailable = "N/A"
            
            var description: String {
                return self.rawValue
            }
        }
        
        guard let interfaceNames = CNCopySupportedInterfaces() as? [String] else {
            return "\(SupportedInterfacesQueryResult.notAvailable)"
        }
        
        let foundKeys: [String] = interfaceNames.flatMap { name in
            guard let info = CNCopyCurrentNetworkInfo(name as CFString) as? [String:AnyObject] else {
                return nil
            }
            guard let id = info[networkInfoDictionaryKey as String] as? String else {
                return nil
            }
            return id
        }
        return foundKeys.first ?? "\(SupportedInterfacesQueryResult.notAvailable)"
    }
}