#51 crypto system

lockbox/util/bit.lua

@@ -0,0 +1,25 @@
+local ok, e
+ok = nil
+if not ok then
+    ok, e = pcall(require, "bit") -- the LuaJIT one ?
+end
+if not ok then
+    ok, e = pcall(require, "bit32") -- Lua 5.2
+end
+if not ok then
+    ok, e = pcall(require, "bit.numberlua") -- for Lua 5.1, https://github.com/tst2005/lua-bit-numberlua/
+end
+if not ok then
+    error("no bitwise support found", 2)
+end
+assert(type(e) == "table", "invalid bit module")
+
+-- Workaround to support Lua 5.2 bit32 API with the LuaJIT bit one
+if e.rol and not e.lrotate then
+    e.lrotate = e.rol
+end
+if e.ror and not e.rrotate then
+    e.rrotate = e.ror
+end
+
+return e