CSSM_HEADERVISION
This data structure represents the version number of a key header structure. This version number is an integer that increments with each format revision of CSSM_KEYHEADER. The current revision number is represented by CSSM_KEYHEADER_VERSION, which equals 2 in this release of OCSF.
typedef uint32 CSSM_HEADERVERSION
#define CSSM_KEYHEADER_VERSION (2)