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

*** 20,33 ****
   */
  
  /*
   * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
- #pragma ident   "%Z%%M% %I%     %E% SMI"
- 
  #include <pthread.h>
  #include <errno.h>
  #include <stdio.h>
  #include <strings.h>
  #include <sys/crypto/ioctl.h>
--- 20,32 ----
   */
  
  /*
   * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
+  * Copyright (c) 2018, Joyent, Inc.
   */
  
  #include <pthread.h>
  #include <errno.h>
  #include <stdio.h>
  #include <strings.h>
  #include <sys/crypto/ioctl.h>
*** 232,257 ****
          session_p = (soft_session_t *)s;
          if (session_p == NULL)
                  return;
  
          if (opflag & OP_SIGN) {
!                 if (session_p->sign.context == NULL)
!                         return;
!                 bzero(session_p->sign.context, sizeof (soft_hmac_ctx_t));
!                 free(session_p->sign.context);
                  session_p->sign.context = NULL;
                  session_p->sign.flags = 0;
          } else if (opflag & OP_VERIFY) {
!                 if (session_p->verify.context == NULL)
!                         return;
!                 bzero(session_p->verify.context, sizeof (soft_hmac_ctx_t));
!                 free(session_p->verify.context);
                  session_p->verify.context = NULL;
                  session_p->verify.flags = 0;
          } else {
-                 if (session_p->digest.context == NULL)
-                         return;
                  free(session_p->digest.context);
                  session_p->digest.context = NULL;
                  session_p->digest.flags = 0;
          }
  }
--- 231,250 ----
          session_p = (soft_session_t *)s;
          if (session_p == NULL)
                  return;
  
          if (opflag & OP_SIGN) {
!                 freezero(session_p->sign.context,
!                     sizeof (soft_hmac_ctx_t));
                  session_p->sign.context = NULL;
                  session_p->sign.flags = 0;
          } else if (opflag & OP_VERIFY) {
!                 freezero(session_p->verify.context,
!                     sizeof (soft_hmac_ctx_t));
                  session_p->verify.context = NULL;
                  session_p->verify.flags = 0;
          } else {
                  free(session_p->digest.context);
                  session_p->digest.context = NULL;
                  session_p->digest.flags = 0;
          }
  }