Added asn1_delete_structure2().

The new function accepts additional flags to be used during deinitialization.
For the moment the only available flag is ASN1_DELETE_FLAG_ZEROIZE which zeroizes
all values in the structure prior to deinitialization.

5 files changed, 38 insertions, 7 deletions

diff --git a/NEWS b/NEWS
index f7fc31a..99b7105 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,8 @@
 GNU Libtasn1 NEWS                                     -*- outline -*-
 
 * Noteworthy changes in release 3.4 (unreleased) [stable]
+- Added asn1_delete_structure2() which allows zeroizing the contents
+  of all values in the structure prior to deinitialization.
 
 * Noteworthy changes in release 3.3 (released 2013-03-23) [stable]
 - More precise overflow checks using gnulib's intprops module.
diff --git a/lib/libtasn1.h b/lib/libtasn1.h
index a2da884..f29e6a4 100644
--- a/lib/libtasn1.h
+++ b/lib/libtasn1.h
@@ -168,6 +168,12 @@ extern "C"
 #define ASN1_ETYPE_UTC_TIME       36
 #define ASN1_ETYPE_GENERALIZED_TIME 37
 
+/* Flags used by asn1_delete_structure2() */
+
+/* makes sure the values are zeroized prior to deinitialization */
+#define ASN1_DELETE_FLAG_ZEROIZE 1
+
+
   struct asn1_data_node_st
   {
     const char *name;		/* Node name */
@@ -214,6 +220,8 @@ extern "C"
 
   extern ASN1_API int asn1_delete_structure (asn1_node * structure);
 
+  extern ASN1_API int asn1_delete_structure2 (asn1_node * structure, unsigned int flags);
+
   extern ASN1_API int
     asn1_delete_element (asn1_node structure, const char *element_name);
 
diff --git a/lib/parser_aux.c b/lib/parser_aux.c
index 34bf1e7..fccfed5 100644
--- a/lib/parser_aux.c
+++ b/lib/parser_aux.c
@@ -450,12 +450,16 @@ _asn1_get_last_right (asn1_node node)
 /*              element (not the elements pointed by it).         */
 /* Parameters:                                                    */
 /*   node: NODE_ASN element pointer.                              */
+/*   flags: ASN1_DELETE_FLAG_*                                    */
 /******************************************************************/
 void
-_asn1_remove_node (asn1_node node)
+_asn1_remove_node (asn1_node node, unsigned int flags)
 {
   if (node == NULL)
     return;
+    
+  if (flags & ASN1_DELETE_FLAG_ZEROIZE)
+    memset(node->value, 0, node->value_len);
 
   if (node->value != NULL && node->value != node->small_value)
     free (node->value);
@@ -517,7 +521,7 @@ _asn1_delete_list_and_nodes (void)
     {
       listElement = firstElement;
       firstElement = firstElement->next;
-      _asn1_remove_node (listElement->node);
+      _asn1_remove_node (listElement->node, 0);
       free (listElement);
     }
 }
@@ -672,7 +676,7 @@ _asn1_expand_object_id (asn1_node node)
 			  || !(p3->type & CONST_ASSIGN))
 			return ASN1_ELEMENT_NOT_FOUND;
 		      _asn1_set_down (p, p2->right);
-		      _asn1_remove_node (p2);
+		      _asn1_remove_node (p2, 0);
 		      p2 = p;
 		      p4 = p3->down;
 		      while (p4)
diff --git a/lib/parser_aux.h b/lib/parser_aux.h
index 24663eb..5fd4e64 100644
--- a/lib/parser_aux.h
+++ b/lib/parser_aux.h
@@ -48,7 +48,7 @@ asn1_node _asn1_set_right (asn1_node node, asn1_node right);
 
 asn1_node _asn1_get_last_right (asn1_node node);
 
-void _asn1_remove_node (asn1_node node);
+void _asn1_remove_node (asn1_node node, unsigned int flags);
 
 void _asn1_delete_list (void);
 
diff --git a/lib/structure.c b/lib/structure.c
index 22f1037..611ed94 100644
--- a/lib/structure.c
+++ b/lib/structure.c
@@ -287,6 +287,23 @@ asn1_array2tree (const asn1_static_node * array, asn1_node * definitions,
 int
 asn1_delete_structure (asn1_node * structure)
 {
+  return asn1_delete_structure2(structure, 0);
+}
+
+/**
+ * asn1_delete_structure2:
+ * @structure: pointer to the structure that you want to delete.
+ * @flags: additional flags (see %ASN1_DELETE_FLAG)
+ *
+ * Deletes the structure *@structure.  At the end, *@structure is set
+ * to NULL.
+ *
+ * Returns: %ASN1_SUCCESS if successful, %ASN1_ELEMENT_NOT_FOUND if
+ *   *@structure was NULL.
+ **/
+int
+asn1_delete_structure2 (asn1_node * structure, unsigned int flags)
+{
   asn1_node p, p2, p3;
 
   if (*structure == NULL)
@@ -306,7 +323,7 @@ asn1_delete_structure (asn1_node * structure)
 	    {
 	      p3 = _asn1_find_up (p);
 	      _asn1_set_down (p3, p2);
-	      _asn1_remove_node (p);
+	      _asn1_remove_node (p, flags);
 	      p = p3;
 	    }
 	  else
@@ -325,7 +342,7 @@ asn1_delete_structure (asn1_node * structure)
 		}
 	      else
 		_asn1_set_right (p3, p2);
-	      _asn1_remove_node (p);
+	      _asn1_remove_node (p, flags);
 	      p = NULL;
 	    }
 	}
@@ -598,7 +615,7 @@ _asn1_expand_identifier (asn1_node * node, asn1_node root)
 
 	      if (p == *node)
 		*node = p2;
-	      _asn1_remove_node (p);
+	      _asn1_remove_node (p, 0);
 	      p = p2;
 	      move = DOWN;
 	      continue;