From: REITHER Robert - Contractor <robert.reither@external.thalesgroup.com>
To: u-boot@lists.denx.de
Subject: U-Boot FIT Signature Verification
Date: Wed, 16 Sep 2020 15:31:18 +0000 [thread overview]
Message-ID: <82a6e596a6fe4311918d4f91937460b5@external.thalesgroup.com> (raw)
Hi there
I don't think it would make sense to check for expiration (even in case we would have full certificates like PKCS#7 verifiy)
At our point of the boot process we normally do not have access to a trusted time/date, so any check could be simply spoofed or even worse fails, because wall clock is not initialized properly.
I think even the EFI boot-process (or shim) does not check expiration date of their certificates!
What could make sense is a check for an expired certificate/key at signing time (including intermed certs), but not sure if this would be a too hard restriction (at least for developing/testing). I think a hint for the signer should be enough!
Regards
Robert
On Wed, Sep 16, 2020 at 01:19:03AM +0200, Heinrich Schuchardt wrote:
>
On 9/11/20 7:26 PM, Andrii Voloshyn wrote:
> > Hi there,
> >
> > Does U-boot take into account certificate expiration date when verifying signed images in FIT? In other words, is date stored along with the public key in DTB file?
> >
> > Cheers,
> > Andy
> >
>
> Hello Philippe,
>
> looking at padding_pkcs_15_verify() in lib/rsa/rsa-verify.c I cannot
> find a comparison of the date on which an image was signed with the
> expiry date of the certificate. Shouldn't there be a check? Or did I
> simply look into the wrong function?
I think Simon is the right person to answer this question, but
as far as I know, we don't have any device tree property for the expiration date of a public key. See doc/uImage.FIT/signature.txt.
-Takahiro Akashi
> Best regards
>
> Heinrich
next reply other threads:[~2020-09-16 15:31 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-16 15:31 REITHER Robert - Contractor [this message]
-- strict thread matches above, loose matches on Subject: below --
2020-09-11 17:26 U-Boot FIT Signature Verification Andrii Voloshyn
2020-09-15 23:19 ` Heinrich Schuchardt
2020-09-16 8:13 ` AKASHI Takahiro
2020-09-16 11:14 ` Heinrich Schuchardt
2020-09-16 11:40 ` Joakim Tjernlund
2020-09-16 11:55 ` Heinrich Schuchardt
2020-09-16 12:05 ` Joakim Tjernlund
2020-09-16 12:44 ` Heinrich Schuchardt
2020-09-16 19:54 ` Tom Rini
2020-09-17 5:33 ` takahiro.akashi at linaro.org
2020-09-17 5:57 ` takahiro.akashi at linaro.org
2020-09-17 5:26 ` AKASHI Takahiro
2020-09-16 20:01 ` Philippe REYNES
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