The CERT_PRIVATE_KEY_VALIDITY structure indicates the period of use of the private key corresponding to the certified public key. If the NotBefore component is not present, no statement is made as to when the validity period of the private key commences. If the NotAfter component is not present, no statement is made as to when the validity period of the private key concludes.
CERT_PRIVATE_KEY_VALIDITY is a component of CERT_KEY_ATTRIBUTES_INFO.
typedef struct _CERT_PRIVATE_KEY_VALIDITY{
FILETIME NotBefore;
FILETIME NotAfter;
} CERT_PRIVATE_KEY_VALIDITY, *PCERT_PRIVATE_KEY_VALIDITY;