X509_time_adj
if (X509_time_adj(a_tm, 0, now) == NULL) {
asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time);
return X509_time_adj(s, adj, NULL);
ASN1_TIME *X509_time_adj(ASN1_TIME *s, long adj, time_t *t);