Deceptive default behavior from cert_create and fiptool bbclass.

[milkylainen]

https://github.com/STMicroelectronics/meta-st-stm32mp/blob/kirkstone/classes/fip-utils-stm32mp.bbclass

FIP_SIGN_KEY is used to specify the rot key.

But if that key is not found (wrong path for example),

the bbclass and cert_create silently creates a new rot key,

which obviously doesn't match whatever you were using.

This is a bit annoying. If a key is specified, there is no use in believing that

the user wants a generated rot key...

If rot keys are not stored and presented during build, and for whatever reason export of keys failed or path seems wrong, this will go undetected.

Your build will succeed, but won't start.

What's worse is that you'll be stuck without a functioning fip...

[Jean-Marc S]

Hello

Thanks for your feedback.

We will report this to the owner of this script for analysis and fix if needed.

JM

(for ST internal tracking only: Ticket 134397 - fip-utils: new rot keys generated when FIP_SIGN_KEY rot key not found )

[Jean-Marc S]

Feedback from development team is that they will propose a patch to raise an error message if the external key path is wrong, and then highlight the fact the configuration of the customer has an issue.

Thanks

JM

[milkylainen]

Sounds good. :thumbs_up:

[Erwan SZYMANSKI]

@milkylainen​ ,

Just to be sure to well understand your remark.

Do you say that when you put a wrong path for FIP_SIGN_KEY, bitbake does not return you an error ?

Don't you see something like:

ERROR:<...>/layers/meta-st/meta-st-stm32mp/recipes-bsp/trusted-firmware-a/tf-a-stm32mp_2.6.bb: : 0:01:21

Not able to find "key/stm32mp15/privateKey01.pem" path from current BBPATH var

Considering that the path of the key is wrong for this variable, you should observe something like this isn't it ?

This is to well target your use case for the patch.

Kind regards,

Erwan.

[Erwan SZYMANSKI]

@milkylainen​ ,

Can you also give me the OSTL version on which you work please ?

Kind regards,

Erwan.

[milkylainen]

@Erwan SZYMANSKI​ 

Hi.

Using ecosystem v3.0.0 and openstlinux-5.10-dunfell-mp1-21-03-31.

Regards,

Christian

[Kevin HUBER · Accepted solution]

Hello @milkylainen​ ,

After several test, this problem is not present on maintained OSTL linux version, Ecosystem :

- v3.1

-v4.0.

To be more explicit, if we face this case, Yocto/bitbake returns a such following error:

ERROR: tf-a-stm32mp-v2.6-stm32mp-r1-r0 do_deploy:

Not able to find "key/stm32mp15/wrong_folder/privateKey00.pem" path from current BBPATH var:

Thanks again for your post.

Best Regards,

Kevin

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