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#1 2021-12-01 23:51:12

diamondrail
Contributor
Registered: 2017-08-07
Posts: 35

Translating the Raw number back into a card number/fc/len numbers

This is specifically for a Guardall G-prox II card.

How does the raw number translate into the card number?

I am trying to figure a way to customize card numbers and build a calculator in excel to do the math.

f98c67b8c6318c4725c91190 (raw) <-> 63867 (card)

Last edited by diamondrail (2022-01-20 05:30:48)

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#2 2021-12-02 00:52:46

diamondrail
Contributor
Registered: 2017-08-07
Posts: 35

Re: Translating the Raw number back into a card number/fc/len numbers

I checked on this page: http://proxmark.io/www.proxmark.org/for … 4&p=2.html

and also looked for the datasheets for G-proxii but even after reviewing the pages, I couldn't find the correlation.

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#3 2022-01-18 20:50:40

Charlie
Contributor
Registered: 2017-01-27
Posts: 129

Re: Translating the Raw number back into a card number/fc/len numbers

Hi,

See you're working on these too. Any progress so far?

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#4 2022-01-20 00:52:41

diamondrail
Contributor
Registered: 2017-08-07
Posts: 35

Re: Translating the Raw number back into a card number/fc/len numbers

Not solved yet, getting closer. Will advise.

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#5 2022-01-20 02:25:44

Charlie
Contributor
Registered: 2017-01-27
Posts: 129

Re: Translating the Raw number back into a card number/fc/len numbers

ok, let me know if i can help. Are you working on 26 or 36 bit?

feel free to message me, you can send an email by looking me up on the "user List" up top

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#6 2022-01-20 03:40:56

diamondrail
Contributor
Registered: 2017-08-07
Posts: 35

Re: Translating the Raw number back into a card number/fc/len numbers

36 bit.

Ok. I will reach out.

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#7 2022-01-20 05:24:27

diamondrail
Contributor
Registered: 2017-08-07
Posts: 35

Re: Translating the Raw number back into a card number/fc/len numbers

Charlie wrote:

ok, let me know if i can help. Are you working on 26 or 36 bit?

feel free to message me, you can send an email by looking me up on the "user List" up top

Charlie - your details are hidden - so I couldn't get your email. Look me up and my contact info is temporarily public.

Last edited by diamondrail (2022-01-21 15:59:10)

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#8 2022-01-20 18:58:28

iceman
Administrator
Registered: 2013-04-25
Posts: 9,537
Website

Re: Translating the Raw number back into a card number/fc/len numbers

[usb] pm3 --> lf gp demo --raw f98c67b8c6318c4725c91190
[+] G-Prox-II - len: 36 FC: 10 Card: 63867, Raw: F98C67B8C6318C4725C91190
[usb] pm3 -->

don't spend too much time reinventing the wheel

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#9 2022-01-21 06:02:41

Charlie
Contributor
Registered: 2017-01-27
Posts: 129

Re: Translating the Raw number back into a card number/fc/len numbers

The issue i run into is...

[usb] pm3 --> lf gp demo --raw fa0e0739080a0e9181e05a1c
[+] G-Prox-II - len: 36 FC: 20 Card: 35212, Raw: FA0E0739080A0E9181E05A1C

vs

[usb] pm3 --> lf gp demo --raw f98c67b8c6318c7139ce519e
[+] G-Prox-II - len: 36 FC: 20 Card: 35212, Raw: F98C67B8C6318C7139CE519E
[usb] pm3 --> 

Both Raw data give the same demodulation but only one works on the reader

Last edited by Charlie (2022-01-21 06:06:00)

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#10 2022-01-22 12:22:04

iceman
Administrator
Registered: 2013-04-25
Posts: 9,537
Website

Re: Translating the Raw number back into a card number/fc/len numbers

try to compare the demod code part,  with the two of your samples above.   And see where it doesn't work

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