Change in coreboot[master]: util/chromeos: Verify sha1sums of downloaded recovery images

[Arthur Heymans (Code Review)]

Attention is currently required from: Matt DeVillier, Paul Menzel, Leah Rowe.
Arthur Heymans has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/51168 )

Change subject: util/chromeos: Verify sha1sums of downloaded recovery images
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Patch Set 2:

(1 comment)

File util/chromeos/crosfirmware.sh:

https://review.coreboot.org/c/coreboot/+/51168/comment/63f6a9ba_dbc62bb4 
PS1, Line 51: sha1_list="$(grep sha1 ${_cfgfile} | sed 's/sha1=//g')"
> Because the way the inventory is structured, there's no way to reliably do that. So I currently make an assumption that google always has the correct sha1sum defined for each image.
>
> With that assumption in mind, the logic works just fine.

The structure of the inventory seem such that it can be done in a very reliable way. E.g. the sha1= entry is always 2 lines above the file= entry.

A checksum for a file makes sense, a checksum list of which one has to match the file partially defeats the purpose of doing it.