Atsha204a

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Hi guys

I am using the atsha204a for first time and I want to read the data what I have written in slot 0 so this is the step which I have used

1] Config Write – writing 0x80 0x80 0x80 0xA1
2]Locking Config Zone
3]Writing your 32bytes private key in slot 0
4]Locking Data Zone
and how to unlock the locked config or data zone

 

Regards

Harish

Harish

Last Edited: Thu. Dec 28, 2017 - 05:15 PM
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Hello Friends,

I am using Atsha204 to implement secure boot.

Is their any configuration in which after locking the configzone I can unlock it back ??,because I am new to this device and I have to work with it.

 

Regards

Harish

 

Harish

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Pretty sure there was a recent thread asking the same question, and the answer was no - once it's locked, it's locked.

 

Which makes sense for a security product!

 

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
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  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
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I have one controller in its I2C ATSHA204 device is their. Now I want to use ATSHA204 as an authenticator during the bootup process so I saw Diversified Key Authentication using random number. So I will read the serial number from the device and using the Gendig I will mac value to the ATSHA204 it will give response and in the end I have to compare that response.

I am getting confused here at the end with what should I compare the response with ???

Regards

Harish

Harish

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This is the step which I am following for Diversified key authentication

1) Reading serial number for the ATSHA204 device. I am getting 8 bytes serial number.

2)I am generating 32bytes random number from the function atcab_random(uint8_t*random).

3)Creating a atcab_challenge using the random number as the argument.

4)Creating gendig using atcab_gendig_host(),which takesGENDIG_ZONE_DATA ,as zone argument value,key_id is 0,and passing 8bytes serial number.

5)After this I get a 32 bytes response from ATSHA204.

6)Now by using atcab_mac(),function I am trying to compare the response.

7)I am getting mac_failed as response from ATSHA204 (4 1 0 C3).

I am going somewhere wrong can someone helpmeout.

Regards

Harish

Harish

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Hello Friend's

My system is having a controller and a crypto ic Atsha204. So can I do the diversified key authentication ?

Regards

Harish 

Harish