Use new time routines to avoid possible overflow.

apps/x509.c

@@ -626,7 +626,7 @@ bad:
 		if (!X509_set_subject_name(x,req->req_info->subject)) goto end;
 
 		X509_gmtime_adj(X509_get_notBefore(x),0);
-	        X509_gmtime_adj(X509_get_notAfter(x),(long)60*60*24*days);
+	        X509_gmtime_adj_ex(X509_get_notAfter(x),days, 0, NULL);
 
 		pkey = X509_REQ_get_pubkey(req);
 		X509_set_pubkey(x,pkey);