the 0004 key
Posted at Friday, July 31st, 2009 9:17AM by bxsciencer

is that the file with 3 lines in it? i have a 0104.key, but no 0004.key


re:the 0004 key
Posted at Friday, July 31st, 2009 9:48AM by Brandon

Right, the first line is the public key (n) and the next two lines are the factors (p and q). Now we can create a 0004.key to sign our own OSes.


re:the 0004 key
Posted at Friday, July 31st, 2009 10:22AM by bxsciencer

wait... if they give p and q, couldnt you just find the totient and just make a table for all the possible values of e and d and then just test them?


re:the 0004 key
Posted at Friday, July 31st, 2009 10:33AM by Brandon

e is 17, we've known that for years and it's hard-coded into the boot code.
d is very easily calculated from e, p, and q.

The key to making this work is p and q, which Ben has so graciously provided to us.


re:the 0004 key
Posted at Friday, July 31st, 2009 10:36AM by bxsciencer

oh


re:the 0004 key
Posted at Friday, July 31st, 2009 10:39AM by bxsciencer

i get it now


re:the 0004 key
Posted at Friday, July 31st, 2009 10:48AM by bxsciencer

no. wait. i dont.
i have (hopefully this isnt illegal,like roms)

#1 40AD2431DA2297E4175EAC61A3154FA3D847115794DD330AB7FF36BA59FEDA195FEA7C16743BD7BCED8A0DA885E5E5C34D5BF20D0AB3EF9181ED39BA2C4D898E87
#2 205B2E54E9B5C1FE26CE93261478D3873F3FC41BFFF1F5F934D7A5793A43C1C21C
#3 2197F7707B94079B73858720BF6D4909AB3BEDA1BA9B93112B041340A16ED597B604

so 1 is n and 2,3 are p and q?


re:the 0004 key
Posted at Friday, July 31st, 2009 1:19PM by Brandon

Correct, but those are length-indexed by a single byte (40, 20, and 21) and in Little Endian if I recall correctly.


re:the 0004 key
Posted at Friday, July 31st, 2009 3:46PM by bxsciencer

wait a minute.... im lost. you said p and q are given in the second and third lines, so dont you already have p and q? or is this a different set Benjamin Moody found?


re:the 0004 key
Posted at Friday, July 31st, 2009 3:48PM by Brandon

You're talking about the 0104.key file. In that, we have n, p, and q. That's all we need to sign Flash applications. TI gave it to us.

For the 0004 key, all we had was n (the public key stored in the boot code). What we needed was p and q, and Ben provided that to us. From it, we can derive d, which is what's actually used to sign an OS.


re:the 0004 key
Posted at Friday, July 31st, 2009 4:12PM by bxsciencer

oh... i get it. wow. im so slow


re:the 0004 key
Posted at Friday, August 28th, 2009 3:20PM by KermMartian

Shock! The key remains on the site despite TI's takedown letter!

But in all seriousness, did they get back to you yet/


re:the 0004 key
Posted at Friday, August 28th, 2009 3:53PM by Brandon

They did not.


re:the 0004 key
Posted at Tuesday, September 1st, 2009 10:54AM by JoostinOnline

You are a bold man, Brandon. Your response makes sense as far as I can tell, but that was still a bold move.


re:the 0004 key
Posted at Saturday, September 12th, 2009 9:49PM by jbaldus

Have you contacted the EFF? They were able to get Apple to back down from a similarly specious DMCA takedown. No reasonable person would see this as a violation of DMCA.


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