====== Signed timestamp error margin ======

===== Name =====

    TIMESTAMP_ERROR_MARGIN

===== Header file =====

Configured via ''[[http://git.ipxe.org/ipxe.git/blob/HEAD:/src/config/crypto.h|config/crypto.h]]''.

===== Examples =====

=== Allow no more than five minutes of error ===

    #undef TIMESTAMP_ERROR_MARGIN
    #define TIMESTAMP_ERROR_MARGIN ( 5 * 60 )

=== Allow up to ten years of error ===

    #undef TIMESTAMP_ERROR_MARGIN
    #define TIMESTAMP_ERROR_MARGIN ( 10 * 365 * 24 * 60 * 60 )

===== Description =====

This build option configures the margin of error (in seconds) that will be accepted in any cryptographically signed timestamps (such as X.509 certificate expiry times).

===== See also =====

  * [[:buildcfg|List of all iPXE build options]]

===== Notes =====

The default value for ''TIMESTAMP_ERROR_MARGIN'' is slightly more than twelve hours: this is intended to allow for the fact that there is no viable way for iPXE to determine its local time zone, and so there may be an error of up to twelve hours in the local system time as determined by iPXE.

You should not reduce ''TIMESTAMP_ERROR_MARGIN'' below twelve hours unless you can guarantee that the local system clock will always be set to GMT.