How to communicate with smart card readers conncetd to USB-C port in iOS?

iOS does not have a mechanism for third-party code to talk to generic USB devices [1].

The smart card reader is a custom hardware and not MFi certified. So as per my understanding, I cannot use ExternalAccessory.framework without MFi certification.

True. But even if that were possible, it’s not easy to use EA framework from a CTK appex.

iOS has built-in support for standard USB smart cards (via USB CCID), so the easiest way to achieve your goal is to change your hardware to support that standard.

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[1] iPadOS can do this with DriverKit, but that one of a small set of iPadOS-specific facilities that aren’t on iOS.

Hi  @eskimo , thanks for the update.

iOS has built-in support for standard USB smart cards (via USB CCID), so the easiest way to achieve your goal is to change your hardware to support that standard.

This is interesting. The hardware has USB CCID. Should we use TKSmartCardSlotManager for this? I wrote a basic swift file using TKSmartCardSlotManager

import CryptoTokenKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        // Start observing smart card slot state changes
        startObservingSmartCardSlotStateChanges()
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        
        // Stop observing smart card slot state changes when the view disappears
        stopObservingSmartCardSlotStateChanges()
    }

    func startObservingSmartCardSlotStateChanges() {
        DispatchQueue.global().async {
            if let slotManager = TKSmartCardSlotManager.default {
                while true {
                    let slotNames = slotManager.slotNames // No need for optional binding
                    
                    for reader in slotNames {
                        slotManager.getSlot(withName: reader) { slot in
                            guard let slot = slot else {
                                print("Slot for reader \(reader) is nil")
                                return
                            }
                            
                            let state = slot.state
                            if state.contains(.cardPresent) {
                                // Smart card is present in the slot
                                print("Smart card is present in slot: \(reader)")
                                
                                // Example: Communicate with the smart card
                                if let card = slot.makeSmartCard() {
                                    card.beginSession { session, error in
                                        if let error = error {
                                            print("Error beginning session with smart card: \(error.localizedDescription)")
                                            return
                                        }
                                        // Session started, now you can communicate with the smart card
                                    }
                                }
                            } else if state.contains(.empty) {
                                // Smart card slot is empty
                                print("Smart card slot is empty: \(reader)")
                            } else {
                                // Unknown state or other state
                                print("Smart card slot is in an unknown state: \(reader)")
                            }
                        }
                    }
                    
                    // Poll every few seconds
                    sleep(5)
                }
            } else {
                // Handle the case where 'default' returns nil
                print("TKSmartCardSlotManager.default is nil")
            }
        }
    }

    func stopObservingSmartCardSlotStateChanges() {
    }
}

Do you think this is correct implementation? Your feedback would be helpful

Thanks in advance