1 files changed, 127 insertions, 0 deletions
diff --git a/modules/base/luasrc/sauth.lua b/modules/base/luasrc/sauth.lua
new file mode 100644
index 0000000000..32f172dcda
--- /dev/null
+++ b/modules/base/luasrc/sauth.lua
@@ -0,0 +1,127 @@
+--[[
+
+Session authentication
+(c) 2008 Steven Barth <steven@midlink.org>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+$Id$
+
+]]--
+
+--- LuCI session library.
+module("luci.sauth", package.seeall)
+require("luci.util")
+require("luci.sys")
+require("luci.config")
+local nixio = require "nixio", require "nixio.util"
+local fs = require "nixio.fs"
+
+
+luci.config.sauth = luci.config.sauth or {}
+sessionpath = luci.config.sauth.sessionpath
+sessiontime = tonumber(luci.config.sauth.sessiontime) or 15 * 60
+
+--- Prepare session storage by creating the session directory.
+function prepare()
+	fs.mkdir(sessionpath, 700)
+	if not sane() then
+		error("Security Exception: Session path is not sane!")
+	end
+end
+
+local function _read(id)
+	local blob = fs.readfile(sessionpath .. "/" .. id)
+	return blob
+end
+
+local function _write(id, data)
+	local f = nixio.open(sessionpath .. "/" .. id, "w", 600)
+	f:writeall(data)
+	f:close()
+end
+
+local function _checkid(id)
+	return not not (id and #id == 32 and id:match("^[a-fA-F0-9]+$"))
+end
+
+--- Write session data to a session file.
+-- @param id	Session identifier
+-- @param data	Session data table
+function write(id, data)
+	if not sane() then
+		prepare()
+	end
+
+	assert(_checkid(id), "Security Exception: Session ID is invalid!")
+	assert(type(data) == "table", "Security Exception: Session data invalid!")
+
+	data.atime = luci.sys.uptime()
+
+	_write(id, luci.util.get_bytecode(data))
+end
+
+--- Read a session and return its content.
+-- @param id	Session identifier
+-- @return		Session data table or nil if the given id is not found
+function read(id)
+	if not id or #id == 0 then
+		return nil
+	end
+
+	assert(_checkid(id), "Security Exception: Session ID is invalid!")
+
+	if not sane(sessionpath .. "/" .. id) then
+		return nil
+	end
+
+	local blob = _read(id)
+	local func = loadstring(blob)
+	setfenv(func, {})
+
+	local sess = func()
+	assert(type(sess) == "table", "Session data invalid!")
+
+	if sess.atime and sess.atime + sessiontime < luci.sys.uptime() then
+		kill(id)
+		return nil
+	end
+
+	-- refresh atime in session
+	write(id, sess)
+
+	return sess
+end
+
+--- Check whether Session environment is sane.
+-- @return Boolean status
+function sane(file)
+	return luci.sys.process.info("uid")
+			== fs.stat(file or sessionpath, "uid")
+		and fs.stat(file or sessionpath, "modestr")
+			== (file and "rw-------" or "rwx------")
+end
+
+--- Kills a session
+-- @param id	Session identifier
+function kill(id)
+	assert(_checkid(id), "Security Exception: Session ID is invalid!")
+	fs.unlink(sessionpath .. "/" .. id)
+end
+
+--- Remove all expired session data files
+function reap()
+	if sane() then
+		local id
+		for id in nixio.fs.dir(sessionpath) do
+			if _checkid(id) then
+				-- reading the session will kill it if it is expired
+				read(id)
+			end
+		end
+	end
+end