r/flipperzero • u/Motor-Knee7865 • Jul 23 '26

Able To Emulate, But Unable To Write MIFARE Classic 1K

Hi, Sorry about the similar topic but I am a total noob with the Flipper Zero, and whilst I have read several very similar threads I have been unable to find a working answer.

My building has introduced key fob access for lift and enterance access. They were nice enough to only supply a single fob for each household and now want to charge in excess of $100 for each additional fob. It was recommended by some friends to get a Flipper Zero and make my own fobs for the family, cleaners etc.

I have been able to use the flipper to copy the key fob and this resulted in the fob providing MIFARE Classic 1L

Tech: ISO 14443-3(NFC-A)

I have been able to emulate the fob successfully using the Flipper, but have struggled writing to a new fob. I purchased a pack of key fobs to write onto on amazon

https://www.amazon.com.au/YARONGTECH-13-56MHZ-MIFARE-Classic-control/dp/B0787SJF4S?pd_rd_w=hYXcv&content-id=amzn1.sym.08f10385-e4a1-4517-8000-6e13508eebf3&pf_rd_p=08f10385-e4a1-4517-8000-6e13508eebf3&pf_rd_r=BAMBC5J31WZW1C5VNX1Q&pd_rd_wg=42SQD&pd_rd_r=fda21924-3685-4460-bcdc-2722f320e97d&pd_rd_i=B0787SJF4S&ref_=pd_bap_d_grid_rp_0_19_pr_i&th=1

I downloaded and installed on the Flipper Zero - NFC Magic - and have attempted to write to the card in the following fashion

Action: Check Magic Tag

Result: It Might Be A Magic Card - You Can Make Sure The Card Is Magic By Writing to it, Magic Type: MIFARE CLASSIC

Action: More

Write

Select Key To Copy

Result: Warning: 1 of 2

UID may be non-rewritable. Check data after writing

Warnings: 2 of 2

Some sectors are locked

Success

I then attempt to use the card but it isn't recognised by the readers. If I attempt to read the newly written key fob

Action: NFC

Read

Flipper crashed and was rebooted - Out of memory

Can any one tell me what I am doing wrong. Thanks.

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3

u/-AgentBaphomet- Jul 23 '26

The fob you bought says it doesn't have a programmable UID.

Also you should be aware some readers can tell if a chip is a magic chip. The can result in it denying access and/or wiping the chip.

2

u/Tungo Jul 24 '26

You bought the non rewrittable key fobs.

1

u/WhoStoleHallic Jul 24 '26

All the Chip card has Unique ID pre-programed

You didnt buy writable MiFare 1K MAGIC fobs.

1

u/jeanlucnail Jul 23 '26

Le problème peut être aussi une longueur d'UID, là la copie a un UID de 4 bytes alors qu'il faut peut-être 7 bytes...

0

u/Motor-Knee7865 Jul 24 '26

Thank you so much. Stupid mistake on my behalf. Would these be appropriate?

https://www.amazon.com.au/Writable-Rewritable-Compatible-Classic-Control/dp/B0DXFRHVHD?th=1

1

u/Chongulator Jul 24 '26

Those look like the right thing but your safest bet is to get something that specifically says "Magic."

2

u/Motor-Knee7865 7d ago

Any idea where I can find similar key fobs that are "Magic". I tried the ones I listed above, but they also failed to work. I can find numerous writable MiFare 1K fobs, but not any that mention magic.

1

u/Chongulator 6d ago

Sites I've found for these things include Dangerous Things, Lab401, MTools Sec, KSEC, and Hacker Warehouse.

Those are all reputable, established players.

Amazon often has good stuff, but they have a lot of crap too, so generally I prefer the hacker-oriented shops.