9642 PKCS#11 softtoken should use explicit_bzero
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Alex Wilson <alex.wilson@joyent.com>

*** 19,28 ****
--- 19,29 ----
   * CDDL HEADER END
   */
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
+  * Copyright (c) 2018, Joyent, Inc.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <strings.h>
*** 75,86 ****
          /*
           * Free the storage allocated to a secret key object.
           */
          if (objp->class == CKO_SECRET_KEY) {
                  if (OBJ_SEC(objp) != NULL && OBJ_SEC_VALUE(objp) != NULL) {
!                         bzero(OBJ_SEC_VALUE(objp), OBJ_SEC_VALUE_LEN(objp));
!                         free(OBJ_SEC_VALUE(objp));
                          OBJ_SEC_VALUE(objp) = NULL;
                          OBJ_SEC_VALUE_LEN(objp) = 0;
                  }
                  free(OBJ_SEC(objp));
                  OBJ_SEC(objp) = NULL;
--- 76,86 ----
          /*
           * Free the storage allocated to a secret key object.
           */
          if (objp->class == CKO_SECRET_KEY) {
                  if (OBJ_SEC(objp) != NULL && OBJ_SEC_VALUE(objp) != NULL) {
!                         freezero(OBJ_SEC_VALUE(objp), OBJ_SEC_VALUE_LEN(objp));
                          OBJ_SEC_VALUE(objp) = NULL;
                          OBJ_SEC_VALUE_LEN(objp) = 0;
                  }
                  free(OBJ_SEC(objp));
                  OBJ_SEC(objp) = NULL;