Re: [Suit] CBOR and Firmware Word Alignment

Carsten Bormann <cabo@tzi.org> Tue, 26 June 2018 22:01 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Date: Wed, 27 Jun 2018 00:01:06 +0200
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Subject: Re: [Suit] CBOR and Firmware Word Alignment
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Hi Paul,

CBOR does not have a padding feature (although it would be easy to add one).
Of course you can fake one by including a byte string in front of the to-be-aligned data and dimensioning this just right.
I am not aware of CBOR implementations that support this today, but it should not be too hard to add this.
Alternatively, the word-aligned firmware image could be kept separate from the manifest itself.

Grüße, Carsten


> On Jun 26, 2018, at 20:20, Paul Lambert <paul.lambert@intrinsic-id.com> wrote:
> 
> Has any thought gone into word alignment issues?
> 
> Many platforms require firmware or other data objects to be word aligned. It waould be especially desirable to have large objects (like the firmware) be packaged such that the data does not have to be copied to a new location just to ensure word alignment. Word alignment would also facilitate in-place decryption of the firmeare.
> 
> 
> Paul
> 
> 
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