uTasker bootloader cryptography with iMXRT1064

[Davidino]

Goodmorning to all, and especially @mjbcswitzerland 

I've been using the iMXRT1064-evk board with SDK version 2.9.1.

I've recently tested the uTasker bootloader project with USB-MSD device mode. I followed the guide https://www.utasker.com/docs/iMX/MCUXpresso.pdf, built the bootloaders and modified my application to make it suitable for uTasker (chapter 5).

The application plain code version (*_XiP.bin) works perfectly with the bootloader, but the BEE encrypted version (*_XiP_BEE.bin) doesn't. As a test I've download the encrypted application uTaskerV1.4.14_i.MX-RT1064_SD-USB-MSD_AES256.bin found at the bottom of this page https://www.utasker.com/iMX/RT1064.html. I tried to upload it with uTasker bootloader that I compiled and it works!

Hence I think that the problem is not the bootloader but something concerning the encrypted application file.

I've modified the generate.bat as follow:

SET PATH=%PATH%;C:\myNxp\totalProjectWorkspace\uTasker-GIT-Kinetis\Tools

rem - select the target being built for in order to automate combining production file

set SECRET_KEY="aes256 secret key"
set VECTOR="initial vector"
set MAGIC=234
set AUTHENTICATION=a748b6531124

rem - generate uploadable version (plain code)
uTaskerConvert.exe %1.bin %1_XiP.bin +../boot_header.txt -0x0%MAGIC% -%AUTHENTICATION%

rem - encrypt for OTF XiP operation
rem - used by OTFAD
uTaskerConvert.exe %1.bin %1_OTFAD.bin E=128-70020400 $%SECRET_KEY% $%VECTOR%)
uTaskerConvert.exe %1_OTFAD.bin %1_XiP_OTFAD.bin +../boot_header.txt -0x5%MAGIC% -%AUTHENTICATION%
del %1_OTFAD.bin

rem - used by BEE
uTaskerConvert.exe %1.bin %1_BEE.bin E=128B-70020400 $%SECRET_KEY% $%VECTOR%)
uTaskerConvert.exe %1_BEE.bin %1_XiP_BEE.bin +../boot_header.txt -0x5%MAGIC% -%AUTHENTICATION%
del %1_BEE.bin

The boot_header.txt file is the following:

// We add 760 bytes of padding between the header and the start of code in order to
// align the code on a 1k (0x400) byte boundary (ensures on-the-fly decryption compatibility,
// library compatibility and also allows interrupt vectors to remain in code)

02f8
ffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

ffffffffffffffff
ffffffffffffffff
ffffffffffffffff
ffffffffffffffff

The MCU settings is as follow:

 <chip>
  <memory id='Flash' type='Flash' is_ro='true' can_program='true'></memory>
  <memory id='RAM' type='RAM'></memory>
   <memoryInstance id='PROGRAM_FLASH' derived_from='Flash' location='0x70020400' size='0x3dfc00' driver='MIMXRT1064.cfx'  edited='true'  />
   <memoryInstance id='SRAM_DTC' derived_from='RAM' location='0x20000000' size='0x40000'   edited='true'  />
   <memoryInstance id='SRAM_ITC' derived_from='RAM' location='0x0' size='0x20000'   edited='true'  />
   <memoryInstance id='SRAM_OC' derived_from='RAM' location='0x20200000' size='0xa0000'   edited='true'  />
 </chip>

Have you got any advices?

Thank you in advance.

Best Regards,

Davidino

[gusarambula]

Hello Davidino,

I see that Mark has answered this on the following thread so I'm adding it so it helps as reference to community users. 

https://community.nxp.com/t5/i-MX-Processors/uTasker-bootloader-with-iMXRT1064/m-p/1346556#M180658

Regards,
Gustavo