Messages in this thread | | | Date | Thu, 06 Jun 2013 13:17:23 +0200 | From | Alexander Holler <> | Subject | Re: [PATCH RESEND/V2] crypto: Ignore validity dates of X.509 certificates at loading/parsing time |
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Am 02.05.2013 16:09, schrieb Alexander Holler: > I don't see any real use case where checking the validity dates of X.509 > certificates at parsing time adds any security gain. In contrast, doing so > makes MODSIGN unusable on systems without a RTC (or systems with a possible > wrong date in a existing RTC, or systems where the RTC is read after the keys > got loaded). > > If something really cares about the dates, it should check them at the time > when the certificates are used, not when they are loaded and parsed. > > So just remove the validity check of the dates in the parser. > > Signed-off-by: Alexander Holler <holler@ahsoftware.de> > Cc: stable@vger.kernel.org
As it just happened to me again and I've recently posted some patches which do make it possible to experience the problem on x86 systems too, here is a reminder.
To replay the problem (on x86 or any other arch), apply the 3 patches in this series:
https://lkml.org/lkml/2013/6/5/430
build a kernel with CONFIG_MODULE_SIG_FORCE=y and start that kernel with hctosys=none as kernel command line parameter.
This will disable the "persistent" clock (and any RTC), thus the kernel will refuse to load modules because it doesn't has a valid time when loading the certificate.
Regards,
Alexander Holler
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