S19 Encrypted - Field upgradable Codewarrior Code

Started by johnpititto1976 October 23, 2003
Hi Ladies and Gents,

I have been working with a HCS12DP256 micro under codewarrior v1.2. I
have been asked to create a system where we can field upgrade our
equipment but encrypt the S19 file so that it will not be readable by
our customers. I have seen in codewarrior where to encrypt the source
files with an encryption key. Does anyone know how to go about
decoding the encrypted code on the micro and also what software is
avaliable to distribute to the customer to send the S19 down the
serial port??

Kind Regards,

John Pititto.



Hi,

Just create your S file using a 8/16bit CRC with your own polynomial seed
per record. All stays the same, except for the checksum. But now there is
only one problem, ..........everyone on the list knows your secret now - so
ignore the checksum!!!!!

Frank

----- Original Message -----
From: "johnpititto1976" <>
To: <>
Sent: Thursday, October 23, 2003 12:53 AM
Subject: [68HC12] S19 Encrypted - Field upgradable Codewarrior Code > Hi Ladies and Gents,
>
> I have been working with a HCS12DP256 micro under codewarrior v1.2. I
> have been asked to create a system where we can field upgrade our
> equipment but encrypt the S19 file so that it will not be readable by
> our customers. I have seen in codewarrior where to encrypt the source
> files with an encryption key. Does anyone know how to go about
> decoding the encrypted code on the micro and also what software is
> avaliable to distribute to the customer to send the S19 down the
> serial port??
>
> Kind Regards,
>
> John Pititto. >
> -------------------- >
> ">http://docs.yahoo.com/info/terms/




John

One of the things I've done in the past is to completely remap the S19
record into a binary file of my design. The conversion algorithms are
internal (to the company) and the customer ends up receiving a binary
file. Not knowing what the format of the binary file is (address based/
block based/ etc) it makes it relatively hard for them to mess with it.
We would of course provide the customer with the necessary PC app that
would load the file and transmit the data for flashing.

John Theofanopoulos

> Hi Ladies and Gents,
>
> I have been working with a HCS12DP256 micro under codewarrior v1.2. I
> have been asked to create a system where we can field upgrade our
> equipment but encrypt the S19 file so that it will not be readable by
> our customers. I have seen in codewarrior where to encrypt the source
> files with an encryption key. Does anyone know how to go about
> decoding the encrypted code on the micro and also what software is
> avaliable to distribute to the customer to send the S19 down the
> serial port??
>
> Kind Regards,
>
> John Pititto. > ------------------------ Yahoo! Groups Sponsor
> ---------------------~--> Rent DVDs Online - Over 14,500
> titles. No Late Fees & Free Shipping. Try Netflix for FREE!
> http://us.click.yahoo.com/Tq9otC/XP.FAA/3jkFAA/dN_tlB/TM
>
> --------------------------
> -------~->
>
> -------------------- >
> ">http://docs.yahoo.com/info/terms/
>




>your own polynomial seed Defenatly not what YOU think it does......8<))
----- Original Message -----
From: "Bob White" <>
To: <>
Sent: Thursday, October 23, 2003 12:04 PM
Subject: Re: [68HC12] S19 Encrypted - Field upgradable Codewarrior Code > Hi Frank,
>
> What does create your S file using a 8/16bit CRC with your own polynomial
> seed
> per record. mean?
>
> Thanks,
> bob white
>
> ----- Original Message -----
> From: "linktek" <>
> To: <>
> Sent: Thursday, October 23, 2003 1:34 AM
> Subject: Re: [68HC12] S19 Encrypted - Field upgradable Codewarrior Code > Hi,
>
> Just create your S file using a 8/16bit CRC with your own polynomial seed
> per record. All stays the same, except for the checksum. But now there is
> only one problem, ..........everyone on the list knows your secret now -
so
> ignore the checksum!!!!!
>
> Frank
>
> ----- Original Message -----
> From: "johnpititto1976" <>
> To: <>
> Sent: Thursday, October 23, 2003 12:53 AM
> Subject: [68HC12] S19 Encrypted - Field upgradable Codewarrior Code > > Hi Ladies and Gents,
> >
> > I have been working with a HCS12DP256 micro under codewarrior v1.2. I
> > have been asked to create a system where we can field upgrade our
> > equipment but encrypt the S19 file so that it will not be readable by
> > our customers. I have seen in codewarrior where to encrypt the source
> > files with an encryption key. Does anyone know how to go about
> > decoding the encrypted code on the micro and also what software is
> > avaliable to distribute to the customer to send the S19 down the
> > serial port??
> >
> > Kind Regards,
> >
> > John Pititto.
> >
> >
> >
> > --------------------
> >
> >
> >
> > ">http://docs.yahoo.com/info/terms/
> >
> >
> -------------------- >
> ">http://docs.yahoo.com/info/terms/ > -------------------- >
> ">http://docs.yahoo.com/info/terms/