HSE Stream Hash with Scatter/gather input.

[phuong_nguyenle]

My project request to stream hash with separated location of data. for secured flashing E.g:

- 1st 4bytes are in RAM 1

- 2nd 4byte are in RAM 2

- the remaining byte (is in programming sequence so that need stream Hashing) in FLASH.

Can I use Scatter/gather input for 1st and 2nd chunks as input in START? Then the remaining bytes shall be UPDATE later?

[lukaszadrapa]

Hi @phuong_nguyenle 

Yes, it is possible to use streaming and scatter/gather input at the same time.

Attached is simple demo.

However, keep in mind that there's following limitation:

And hash block size is:

So, each stream call requires to have data aligned to n*hash_block_size.

You can have 4 bytes on one address, next 4 bytes on second address and next data on another address. This can be covered by scatter gather. But it must be n*hash_block_size in total.

Regards,

Lukas

[lukaszadrapa]

There are some troubles with the screenshot about hash block size, so I will attach it here.