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

@@ -20,14 +20,13 @@
  */
 
 /*
  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ * Copyright (c) 2018, Joyent, Inc.
  */
 
-#pragma ident   "%Z%%M% %I%     %E% SMI"
-
 #include <pthread.h>
 #include <errno.h>
 #include <stdio.h>
 #include <strings.h>
 #include <sys/crypto/ioctl.h>

@@ -232,26 +231,20 @@
         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);
+                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) {
-                if (session_p->verify.context == NULL)
-                        return;
-                bzero(session_p->verify.context, sizeof (soft_hmac_ctx_t));
-                free(session_p->verify.context);
+                freezero(session_p->verify.context,
+                    sizeof (soft_hmac_ctx_t));
                 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;
         }
 }