void silc_hash_table_find_foreach(SilcHashTable ht, void *key,
                                      SilcHashForeach foreach,
                                      void *user_context);

    As the hash table is collision resistant it is possible to save duplicate
    keys to the hash table. This function can be used to find all keys
    and contexts from the hash table that are found using the `key'. The
    `foreach' is called for every found key. If no entries can be found
    the `foreach' will be called once with the context set NULL and
    `key' and `user_context' sent to the function.

    The hash table will not be rehashed during the traversing of the table,
    even if the table was marked as auto rehashable.  The caller also must
    not call silc_hash_table_rehash while traversing the table.