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 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
+  * Copyright (c) 2018, Joyent, Inc.
   */
  
  #include <strings.h>
  #include <md5.h>
  #include <pthread.h>
*** 300,310 ****
                  break;
          }
  
          /* Paranoia on behalf of C_DigestKey callers: bzero the context */
          if (session_p->digest.flags & CRYPTO_KEY_DIGESTED) {
!                 bzero(session_p->digest.context, len);
                  session_p->digest.flags &= ~CRYPTO_KEY_DIGESTED;
          }
          *pulDigestLen = digestLen;
          (void) pthread_mutex_lock(&session_p->session_mutex);
          free(session_p->digest.context);
--- 301,311 ----
                  break;
          }
  
          /* Paranoia on behalf of C_DigestKey callers: bzero the context */
          if (session_p->digest.flags & CRYPTO_KEY_DIGESTED) {
!                 explicit_bzero(session_p->digest.context, len);
                  session_p->digest.flags &= ~CRYPTO_KEY_DIGESTED;
          }
          *pulDigestLen = digestLen;
          (void) pthread_mutex_lock(&session_p->session_mutex);
          free(session_p->digest.context);