NTAG424 programming tool recommendations with TagXplorer

[whitelands]

Hello! I'm quite new to this and not very technical, but I have some basic coding knowledge. I'm currently working on a personal project with the NTAG424, and my goal is to program the tag so I can retrieve the UID, counter, and CMAC.

At first, I bought an ACR122U, but TagXplorer said the device is not supported. I then tried using GoToTags, but it failed to write to the NTAG424. I assumed the issue was due to the outdated reader, so I purchased an ACR1252, as recommended by ChatGPT, but I faced the same result.

Therefore, none of my readers are useful / or being used right now.

So far, I’ve only had success using the NXP TagWriter app on Android, where I was able to configure SDM, counter, UID, and CMAC with offsets. For example, I got the following output:

http://localhost:3000/?uid=043D61F28D1F90x000007x69A1ABA44666D191

However, the Android app TagWriter doesn’t let me set a custom AES key (01, 02 , 03), and it seems there’s no equivalent app for iOS that supports NTAG424 programming.

My questions:

1- What is the best NFC reader that is fully compatible with TagXplorer for NTAG424 programming?

2- Is there any way to program NTAG424 (especially with setting AES key) using Android, iOS, or Windows with the readers I already have (ACR122U or ACR1252)?

3- So with Android TagWriter, you can write NTAG424, and there's an option to choose encryption 01, 02, 03, but what is the default value, and is there any way to set that? 

4- Is there any easy tutorial to program NTAG424 for a beginner like me?

Much appreciated!  

[lukas_l]

NTAG424 is funny that way. I haven´t found any tool so far that fully supports them. 

To your questions:

1. The reader probably is not the problem. TagXplorer is not supporting the change of the underlying settings of the NTAG424. You would probably need something like RFIDDiscover.

2. As stated above the readers should be fine. You can use all features of NTAG424 with a simple ISO-14443 A Reader. You need the right tool. As above i think RFIDDiscover should help here.

3. I think the TagWriter app is setup for normal MIFARE or DESFIRE Cards. NTAG424 has different commands and options.

4. Don´t think so. Short summary of what you need to do, to change AES Keys on an NTAG424:

• Connect to card using normal ISO-14443 A or other supported protocol
• Select the card application with the ISO select file command
• Authenticate with the Master Key. By default 16x 0x00
• Change AES Keys with the change Key Command using AES encrypted secure messaging in Full Mode.   

That is a rough guideline what you have to do. There are a lot of pitfalls in between.

I hope this was at least a little helpful.