Re: A89: Re: How TI's keys work

[Prev][Next][Index][Thread]

Re: A89: Re: How TI's keys work


TI may be crazy, but they were pretty smart when they came up with
this application bit.  They will not sign any applications unless you
buy the Educational version (limited amoutn of signs) or the
Professional version (unlimited).  As someone previously said, (I think
SMN) the signing is based on these certificates.  You get a certificate
with your calculators information, specifically the serial number (I
think).  Then they make the app so that it will run on a calculator with
one specified serial number.  
     As to you question "Are they crazy?", No.  Apps were not meant for
games, but for professional software that could be developed by
professionals (several professors with PHD's were on the sdk beta team)
and sold to schools and the such.  Although apps can be used for games. 
     Hope this will clear things up.  

P.S - Someone please correct me if I was wrong on anything (*cough* Dan
E. *cough*)
     
     - Matt

Bryan Rabeler wrote:
> 
> So are you saying that in genereal, TI won't sign apps if you wrote them
> using the free SDK?  Are they crazy?  Do they want to stop us from making
> games altogether?
> 
> Bryan
> 
> ----- Original Message -----
> From: "Scott Noveck" <noveck@pluto.njcc.com>
> To: <assembly-89@lists.ticalc.org>
> Sent: Thursday, December 02, 1999 4:14 PM
> Subject: A89: How TI's keys work
> 
> >
> > Judging by the 83+ SDK beta, you guys are all waaaaay off.
> >
> > First of all, the way app signing works is different from what you've
> > described.  The application itself is just modified to tell the calc that
> it
> > requires some "certificate(s)" to run.  The certificates are what has to
> be
> > generated specifically for each serial number, and THESE are heavily
> > encrypted.  And I doubt you'll get anything at all out of that.
> >
> > Second, TI does NOT just sign any app you send them.  Normally, they'll
> only
> > do it for those who BUY the SDK - for all other purposes, the free SDK is
> > just a listing of ROM addresses.  The 83+ apps out now - like calcsys -
> were
> > signed because TI has given us SDK beta testers the opportunity to get an
> > app signed for our work -- actually a fair decision on their part.
> >
> > Also, the serial number on any HW1 calc can be changed.  The whole reason
> > HW2 was released is to fix the security bug allowing ROM modification on
> old
> > calcs.  FYI, it's the same bug Archive Utility uses, and although no one's
> > tried yet the address is known (I've seen it somewhere) and it COULD
> > theoretically be done.
> >
> >     -Scott
> >
> >
> >
Follow-Ups: References: