kc7gr
Regular Member
- Joined
- Mar 10, 2012
- Messages
- 15
Fellow techies,
Mars has said it's OK for me to post details about my explorations of iButtons, and how they relate to Motorola products. I'm going to do so, with thanks, as I've hit the metaphorical brick wall and I'm hoping this form of impromptu 'crowd-sourcing' will have better results.
My initial goal is to learn what, exactly, the connection is between a given iButton's hardware serial number (lasered in during manufacture) and the first eight bytes of each of the four files present on the iButton.
What I've done along these lines, to date, is use the publicly-available development tools (http://www.maximintegrated.com/products/ibutton/software/sdk/sdks.cfm), under Windows XP, to do memory dumps of two iButton ASK's known to be coded for the same system. These dumps were then compared, side-by-side. The buttons themselves were the now-discontinued DS1994-F5. Motorola has since taken to using the DS1996-F5, which is current production.
I find it interesting neither one of those iButton models has any sort of onboard hardware encryption (there are ones with SHA-1 built in).
In any case, a pattern was clearly visible on the first read-through. All numeric notations are in hex.
The first button's hardware serial: 26 00 00 00 94 88 BA 04
The first eight bytes of each of the files looked like this: B9 58 D4 5D 82 CE 15 48
The second button's hardware serial: 53 00 00 00 94 9B 58 04
The first eight bytes of each file on the second button: CC 58 D4 5D 82 DD F7 48
I find it most interesting bytes 2, 3 and 4 are identical between each iButton, as these are the positions where the hardware serial number has nothing but zeros.
Other than seeing the bytes of the other files also be identical between buttons (with the exception of what I suspect are checksum values), this is as far as I've gotten. I invite anyone who enjoys a good brain-teaser to apply their mental gears to this stuff and see what pops out the other side.
Happy cogitating. ;-)
Mars has said it's OK for me to post details about my explorations of iButtons, and how they relate to Motorola products. I'm going to do so, with thanks, as I've hit the metaphorical brick wall and I'm hoping this form of impromptu 'crowd-sourcing' will have better results.
My initial goal is to learn what, exactly, the connection is between a given iButton's hardware serial number (lasered in during manufacture) and the first eight bytes of each of the four files present on the iButton.
What I've done along these lines, to date, is use the publicly-available development tools (http://www.maximintegrated.com/products/ibutton/software/sdk/sdks.cfm), under Windows XP, to do memory dumps of two iButton ASK's known to be coded for the same system. These dumps were then compared, side-by-side. The buttons themselves were the now-discontinued DS1994-F5. Motorola has since taken to using the DS1996-F5, which is current production.
I find it interesting neither one of those iButton models has any sort of onboard hardware encryption (there are ones with SHA-1 built in).
In any case, a pattern was clearly visible on the first read-through. All numeric notations are in hex.
The first button's hardware serial: 26 00 00 00 94 88 BA 04
The first eight bytes of each of the files looked like this: B9 58 D4 5D 82 CE 15 48
The second button's hardware serial: 53 00 00 00 94 9B 58 04
The first eight bytes of each file on the second button: CC 58 D4 5D 82 DD F7 48
I find it most interesting bytes 2, 3 and 4 are identical between each iButton, as these are the positions where the hardware serial number has nothing but zeros.
Other than seeing the bytes of the other files also be identical between buttons (with the exception of what I suspect are checksum values), this is as far as I've gotten. I invite anyone who enjoys a good brain-teaser to apply their mental gears to this stuff and see what pops out the other side.
Happy cogitating. ;-)
