[A83] Re: apps
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[A83] Re: apps
Ah,
ofcourse, I forgot about the calc-ID's...
Dan Englender wrote:
>> To my knowledge, it tells the calc to allow apps that are signed with
>> the developer signature.
>
> .....Applications are signed with a key for a specific ID. For example, the
> shareware/freeware key (which is available only to TI) signs applications
> for the 0104 ID (my personal ID is 9F04). All calculators can load
> applications signed for the 0104 ID. When you sign an application with a
> key, it creates some sort of data (I'll call it a checksum) which is used by
> the calculator to validate the application.
> When you load the application onto the calculator, it's checked against the
> certificates you have loaded onto your calculator, and if you don't have the
> required certificate, the calculator rejects the application.
>
>> But hey, if someone were to make his developer certificate and signing
>> available to anyone,
>> we could simply sign apps with that signature, and put the specific
>> developer signature with it.
>
> .....This would not work. The problem is with the developer certificate.
> Certificates are also validated when sent to the calculator. This time,
> it's validated based on your serial number. Of course, there's encryption
> involved, so you can't just open up the certificate file and change the
> numbers. So if you have the same serial number as someone else (which
> obviously you don't), you could load their certificates, and thus their
> applications. Otherwise, you're stuck.
>
>> But, since we know TI longer than today, they 'll probably have included
>> some statement in some license, stating it to be "illegal" to distribute
>> one's developer certificate and signings...
>
> .....As far as I know, there is no such clause in any license. Just having a
> key and certificate doesn't help you at all. Just like if someone purchases
> an application from TI, they can send the application to you and you wont be
> able to use it.
>
> -Dan Englender
>
> ----- Original Message -----
>
>> To my knowledge, it tells the calc to allow apps that are signed with
>> the developer signature.
>>
>> But hey, if someone were to make his developer certificate and signing
>> available to anyone,
>> we could simply sign apps with that signature, and put the specific
>> developer signature with it.
>>
>> But, since we know TI longer than today, they 'll probably have included
>> some statement in some license, stating it to be "illegal" to distribute
>> one's developer certificate and signings...
>>
>> Someone, please verify this!!
>>
>> ...and think of some legal trick to circumvent this. (e.g. making all
>> apps made with that certificate "beta stage" (officially, that is) in
>> case they stated that the dev certif. can only be used for beta testing
>> apps...)
>>
>> --Peter Martijn
>>
>> Gavin Olson wrote:
>>
>>>> You send them the unsigned application, and they sign it. You can make
>>>> applications yourself, and run them on your calc if you get a developer
>>>> certificate for your calc from TI. Or use their Flash Simulator, or
>>>
> the
>
>>>> upcoming VTI. I wrote a plugin for Assembly Studio 8x to make
>>>
> applications
>
>>>> (.hex files).
>>>
>>>
>>> What does this developer certificate on the calc do to make unsigned
>>
> apps
>
>>> work?
>>>
>>>
>>>
>>>
>>>
References: