[En-Nut-Discussion] [PATCH 1/2] FIX: accept certificate without expiration date

Krzysztof Sawicki krzysztof.sawicki at mlabs.pl
Tue Apr 25 09:35:40 CEST 2017

On 24.04.2017 16:34, Uwe Bonnes wrote:
>>>>>> "Krzysztof" == Krzysztof Sawicki <krzysztof.sawicki at mlabs.pl> writes:
>     Krzysztof> RFC5280
>     Krzysztof> "In some situations, devices are given certificates for which
>     Krzysztof> no good expiration date can be assigned. For example, a
>     Krzysztof> device could be issued a certificate that binds its model and
>     Krzysztof> serial number to its public key; such a certificate is
>     Krzysztof> intended to be used for the entire lifetime of the device."
> Krzysztof,
> is the problem really existant? If you emit a certificate and set not_after =
> (time_t) 0x7fffffff, the check (tv.tv_sec > cert->not_after) will never
> trigger with a 32 bit time implementataion.
> Otherwise the standard talks about a constant of (GeneralizedTime)
> 99991231235959Z as marker.

problem really exists, I checked this again to be 100% sure. time_t aka 
long is signed and both tv.tv_sec and cert->not_after are of type 
time_t. So we compare two signed ints. BTW (time_t)(-1)=0xFFFFFFFF not 
0x7FFFFFFF, but this makes no difference in the situation.

Krzysztof Sawicki
MLabs sp. z o.o.
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