allow hash tables to be randomise

To avoid hash table collision attacks (n.runs-SA-2011.004)
Note that this options is *off* by default, but it is reasonable
to consider reversing this.

Signed-off-by: Steve Bennett <steveb@workware.net.au>

1 files changed, 2 insertions, 1 deletions

diff --git a/jim.h b/jim.h
index 9f4813d..27e9e92 100644
--- a/jim.h
+++ b/jim.h
@@ -217,6 +217,7 @@ typedef struct Jim_HashTable {
     unsigned int sizemask;
     unsigned int used;
     unsigned int collisions;
+    unsigned int uniq;
     void *privdata;
 } Jim_HashTable;
 
@@ -257,7 +258,7 @@ typedef struct Jim_HashTableIterator {
         (ht)->type->keyCompare((ht)->privdata, key1, key2) : \
         (key1) == (key2))
 
-#define Jim_HashKey(ht, key) (ht)->type->hashFunction(key)
+#define Jim_HashKey(ht, key) ((ht)->type->hashFunction(key) + (ht)->uniq)
 
 #define Jim_GetHashEntryKey(he) ((he)->key)
 #define Jim_GetHashEntryVal(he) ((he)->val)