191 lines
5.5 KiB
Lua

---
-- Library methods for handling Cassandra Thrift communication as client
--
-- @author Vlatko Kosturjak
-- @copyright Same as Nmap--See https://nmap.org/book/man-legal.html
--
-- Version 0.1
--
local stdnse = require "stdnse"
local string = require "string"
_ENV = stdnse.module("cassandra", stdnse.seeall)
--[[
Cassandra Thrift protocol implementation.
For more information about Cassandra, see:
http://cassandra.apache.org/
]]--
-- Protocol magic strings
CASSANDRAREQ = "\x80\x01\x00\x01"
CASSANDRARESP = "\x80\x01\x00\x02"
CASSLOGINMAGIC = "\x00\x00\x00\x01\x0c\x00\x01\x0d\x00\x01\x0b\x0b\x00\x00\x00\x02"
LOGINSUCC = "\x00\x00\x00\x01\x00"
LOGINFAIL = "\x00\x00\x00\x01\x0b"
LOGINACC = "\x00\x00\x00\x01\x0c"
--Returns string in cassandra format for login
--@param username to put in format
--@param password to put in format
--@return str : string in cassandra format for login
function loginstr (username, password)
return CASSANDRAREQ
.. string.pack(">s4", "login")
.. CASSLOGINMAGIC
.. string.pack(">s4s4s4s4", "username", username, "password", password)
.. "\x00\x00" -- add two null on the end
end
--Invokes command over socket and returns the response
--@param socket to connect to
--@param command to invoke
--@param cnt is protocol count
--@return status : true if ok; false if bad
--@return result : value if status ok, error msg if bad
function cmdstr (command,cnt)
return CASSANDRAREQ
.. string.pack(">s4I4", command, cnt)
.. "\x00" -- add null on the end
end
--Invokes command over socket and returns the response
--@param socket to connect to
--@param command to invoke
--@param cnt is protocol count
--@return status : true if ok; false if bad
--@return result : value if status ok, error msg if bad
function sendcmd (socket, command, cnt)
local cmdstr = cmdstr (command,cnt)
local response
local status, err = socket:send(string.pack(">I4", #cmdstr))
if ( not(status) ) then
return false, "error sending packet length"
end
status, err = socket:send(cmdstr)
if ( not(status) ) then
return false, "error sending packet payload"
end
status, response = socket:receive_bytes(4)
if ( not(status) ) then
return false, "error receiving length"
end
local size = string.unpack(">I4", response)
if #response < size + 4 then
local resp2
status, resp2 = socket:receive_bytes(size + 4 - #response)
if ( not(status) ) then
return false, "error receiving payload"
end
response = response .. resp2
end
-- magic response starts at 5th byte for 4 bytes, 4 byte for length + length of string command
if response:sub(5, 8 + 4 + #command) ~= CASSANDRARESP .. string.pack(">s4", command) then
return false, "protocol response error"
end
return true, response
end
--Return Cluster Name
--@param socket to connect to
--@param cnt is protocol count
--@return status : true if ok; false if bad
--@return result : value if status ok, error msg if bad
function describe_cluster_name (socket,cnt)
local cname = "describe_cluster_name"
local status,resp = sendcmd(socket,cname,cnt)
if (not(status)) then
stdnse.debug1("sendcmd"..resp)
return false, "error in communication"
end
-- grab the size
-- pktlen(4) + CASSANDRARESP(4) + lencmd(4) + lencmd(v) + params(7) + next byte position
local position = 12 + #cname + 7 + 1
local value = string.unpack(">s4", resp, position)
return true, value
end
--Return API version
--@param socket to connect to
--@param cnt is protocol count
--@return status : true if ok; false if bad
--@return result : value if status ok, error msg if bad
function describe_version (socket,cnt)
local cname = "describe_version"
local status,resp = sendcmd(socket,cname,cnt)
if (not(status)) then
stdnse.debug1("sendcmd"..resp)
return false, "error in communication"
end
-- grab the size
-- pktlen(4) + CASSANDRARESP(4) + lencmd(4) + lencmd(v) + params(7) + next byte position
local position = 12 + #cname + 7 + 1
local value = string.unpack(">s4", resp, position)
return true, value
end
--Login to Cassandra
--@param socket to connect to
--@param username to connect to
--@param password to connect to
--@return status : true if ok; false if bad
--@return result : table of status ok, error msg if bad
--@return if status ok : remaining data read from socket but not used
function login (socket,username,password)
local loginstr = loginstr (username, password)
local combo = username..":"..password
local status, err = socket:send(string.pack(">I4", #loginstr))
if ( not(status) ) then
stdnse.debug3("cannot send len "..combo)
return false, "Failed to connect to server"
end
status, err = socket:send(loginstr)
if ( not(status) ) then
stdnse.debug3("Sent packet for "..combo)
return false, err
end
local response
status, response = socket:receive_bytes(22)
if ( not(status) ) then
stdnse.debug3("Receive packet for "..combo)
return false, err
end
local size = string.unpack(">I4", response)
local loginresp = string.sub(response,5,17)
if (loginresp ~= CASSANDRARESP .. string.pack(">s4", "login")) then
return false, "protocol error"
end
local magic = string.sub(response,18,22)
stdnse.debug3("packet for "..combo)
stdnse.debug3("packet hex: %s", stdnse.tohex(response) )
stdnse.debug3("size packet hex: %s", stdnse.tohex(size) )
stdnse.debug3("magic packet hex: %s", stdnse.tohex(magic) )
if (magic == LOGINSUCC) then
return true
else
return false, "Login failed."
end
end
return _ENV;