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#1 2017-08-13 13:18:26

ntk
Contributor
Registered: 2015-05-24
Posts: 701

a small study on HID code generating tool by OxFFFF

Regarding this magnificent HID tool link, and a lot more RFID tools treasure

At first I like to thank OxFFFF for the effort to share the interesting tool online, it is very intrigued how it works, and iceman for sharing the tool to the forum....

But I need some more input to understand some differences in HID RAW codes.

Trying to test the OxFFFF's online tool to generate the RAW code I chose the HID 37bit version, because the tool supports 5 different formats. So for a imagination HID fob with following information

    Card Nr: 31
    Card Site Code: 1661
    Card format: 37bit.
    Output format: Raw

I think firstly it is a spelling mistake "PointGuard". secondly checking all the 37bit combinations I can generate

0000001100111110100000000000000111110 (HID farpoint H10304)
0000001100111110100000000000000111110 (HID FAC 37bit )
00000000000000000000000000000001111101 (HID 37bit H10302)
00000000000000000000000000000001111111 (HID generic 37bit)
0001100000000000000000000000000111110 (HID pointguard MDI 37bit)

I do not have a reader to test ,if the coding is working, but when look at the total bits and parities it shows quite a discrepancy between the schemes?

Why?

No doubt OxFFFF must have spent a lot of time to find the bit map, collect and implement raw coding rules, we all appreciate the work, but can someone with real HID reader of these particular type confirm the RAW result should be so? could it be a bit too much in some schemes?

To complete the confusion, followed the thread Wiegand code  in the conversation between Warriors and iceman in post #72 iceman has a different version of 37bit raw code for the same FC/CN combination 1661/31
Facility Code = 1661
Card Number = 31

P                                                                                P
1 0100 0110 0111 1101 000 0000 0000 0001 1111 1
p+ 8x 4bit + 1x3bit +p= 37bit

Huuuummm .... the bit length is 37, but why different parity value to RAW generated by OxFFFF, aren't parity calculation rule not generic??

Last edited by ntk (2017-08-13 13:25:34)

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#2 2017-09-01 05:21:29

0xFFFF
Administrator
From: Vic - Australia
Registered: 2011-05-31
Posts: 632

Re: a small study on HID code generating tool by OxFFFF

I didn't see this post ntk. It slipped through the cracks I guess.
Parity calculation rules are not generic and do not follow any rules. There are heaps of 37bit variants. If I'm missing one (or I've made a mistake), please let me know and I'll update the collection.
You can see the differences between formats by clicking on them on the home page.

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