safer usage of memcpy().

diff --git a/lib/element.c b/lib/element.c
index 8062bce..3f31aa2 100644 (file)
--- a/lib/element.c
+++ b/lib/element.c
@@ -621,7 +621,7 @@ asn1_write_value (asn1_node node_root, const char *name,
        if (ptr_size < data_size) { \
                return ASN1_MEM_ERROR; \
        } else { \
-               if (ptr) \
+               if (ptr && data_size > 0) \
                  memcpy (ptr, data, data_size); \
        }
 
@@ -631,8 +631,9 @@ asn1_write_value (asn1_node node_root, const char *name,
                return ASN1_MEM_ERROR; \
        } else { \
                /* this strcpy is checked */ \
-               if (ptr) \
+               if (ptr) { \
                  _asn1_strcpy (ptr, data); \
+               } \
        }
 
 #define PUT_AS_STR_VALUE( ptr, ptr_size, data, data_size) \
@@ -642,7 +643,8 @@ asn1_write_value (asn1_node node_root, const char *name,
        } else { \
                /* this strcpy is checked */ \
                if (ptr) { \
-                 memcpy (ptr, data, data_size); \
+                 if (data_size > 0) \
+                   memcpy (ptr, data, data_size); \
                  ptr[data_size] = 0; \
                } \
        }
@@ -887,7 +889,8 @@ asn1_read_value_type (asn1_node root, const char *name, void *ivalue,
     case ASN1_ETYPE_OBJECT_ID:
       if (node->type & CONST_ASSIGN)
        {
-         value[0] = 0;
+         if (value)
+               value[0] = 0;
          p = node->down;
          while (p)
            {