--- Library method for communicating over RMI (JRMP + java serialization)
--
-- This is a not complete RMI implementation for Lua, which is meant to be able
-- to invoke methods and parse returnvalues which are simple, basically the java primitives.
-- This can be used to e.g dump out the registry, and perform authentication against
-- e.g JMX-services.
--
-- This library also contains some classes which works pretty much like the
-- java classes BufferedReader, BufferedWriter, DataOutputStream and DataInputStream.
--
-- Most of the methods in the RMIDataStream class is based on the OpenJDK RMI Implementation,
-- and I have kept the methodnames as they are in java, so it should not be too hard to find
-- the corresponding functionality in the jdk codebase to see how things 'should' be done, in case
-- there are bugs or someone wants to make additions. I have only implemented the
-- things that were needed to get things working, but it should be pretty simple to add more
-- functionality by lifting over more stuff from the jdk.
--
-- The interesting classes in OpenJDK are:
-- java.io.ObjectStreamConstants
-- java.io.ObjectStreamClass
-- java.io.ObjectInputStream
-- sun.rmi.transport.StreamRemoteCall
-- and a few more.
--
-- If you want to add calls to classes you know of, you can use e.g Jode to decompile the
-- stub-class or skeleton class and find out the details that are needed to perform an
-- RMI method invokation. Those are
-- Class hashcode
-- Method number (each method gets a number)
-- Arguments f
-- You also need the object id (so the remote server knows what instance you are talking to). That can be
-- fetched from the registry (afaik) but not currently implemented. Some object ids are static : the registry is always 0
--
-- @author Martin Holst Swende
-- @copyright Same as Nmap--See http://nmap.org/book/man-legal.html
-- @see java 1.4 RMI-spec: http://java.sun.com/j2se/1.4.2/docs/guide/rmi/
-- @see java 5 RMI-spec: http://java.sun.com/j2se/1.5.0/docs/guide/rmi/spec/rmiTOC.html
-- @see java 6 RMI-spec : http://java.sun.com/javase/6/docs/technotes/guides/rmi/index.html
-- @see The protocol for Java object serializtion : http://java.sun.com/javase/6/docs/platform/serialization/spec/protocol.html
-- Version 0.2
-- Created 09/06/2010 - v0.1 - created by Martin Holst Swende <martin@swende.se>
-- Fixed more documentation - v0.2 Martin Holst Swende <martin@swende.se>
local bin = require "bin"
local bit = require "bit"
local nmap = require "nmap"
local stdnse = require "stdnse"
local string = require "string"
local table = require "table"
_ENV = stdnse.module("rmi", stdnse.seeall)
-- Some lazy shortcuts
local function dbg(str,...)
local arg={...}
stdnse.print_debug(3,"RMI:"..str, table.unpack(arg))
end
-- Convenience function to both print an error message and return <false, msg>
-- Example usage :
-- if foo ~= "gazonk" then
-- return doh("Foo should be gazonk but was %s", foo)
-- end
local function doh(str,...)
local arg={...}
stdnse.print_debug("RMI-ERR:"..tostring(str), table.unpack(arg))
return false, str
end
---
-- BufferedWriter
-- This buffering writer provide functionality much like javas BufferedWriter.
--
-- BufferedWriter wraps the pack-functionality from bin, and buffers data internally
-- until flush is called. When flush is called, it either sends the data to the socket OR
-- returns the data, if no socket has been set.
--@usage:
-- local bWriter = BufferedWriter:new(socket)
-- local breader= BufferedReader:new(socket)
--
-- bWriter.pack('>i', integer)
-- bWrier.flush() -- sends the data
--
-- if bsocket:canRead(4) then -- Waits until four bytes can be read
-- local packetLength = bsocket:unpack('i') -- Read the four bytess
-- if bsocket:canRead(packetLength) then
-- -- ...continue reading packet values
BufferedWriter = {
new = function(self, socket)
local o = {}
setmetatable(o, self)
self.__index = self
o.writeBuffer = ''
o.pos = 1
o.socket = socket
return o
end,
-- Sends data over the socket
-- (Actually, just buffers until flushed)
-- @return Status (true or false).
-- @return Error code (if status is false).
send = function( self, data )
self.writeBuffer = self.writeBuffer .. data
end,
-- Convenience function, wraps bin
pack = function(self, fmt, ... )
local arg={...}
self.writeBuffer = self.writeBuffer .. bin.pack( fmt, table.unpack(arg))
end,
-- This function flushes the buffer contents, thereby emptying
-- the buffer. If a socket has been supplied, that's where it will be sent
-- otherwise the buffer contents are returned
--@return status
--@return content of buffer, in case no socket was used
flush = function(self)
local content = self.writeBuffer
self.writeBuffer = ''
if not self.socket then
return true, content
end
return self.socket:send(content)
end,
}
---
-- BufferedReader reads data from the supplied socket and contains functionality
-- to read all that is available and store all that is not currently needed, so the caller
-- gets an exact number of bytes (which is not the case with the basic nmap socket implementation)
-- If not enough data is available, it blocks until data is received, thereby handling the case
-- if data is spread over several tcp packets (which is a pitfall for many scripts)
--
-- It wraps unpack from bin for the reading.
-- OBS! You need to check before invoking skip or unpack that there is enough
-- data to read. Since this class does not parse arguments to unpack, it does not
-- know how much data to read ahead on those calls.
--@usage:
-- local bWriter = BufferedWriter:new(socket)
-- local breader= BufferedReader:new(socket)
--
-- bWriter.pack('>i', integer)
-- bWrier.flush() -- sends the data
--
-- if bsocket:canRead(4) then -- Waits until four bytes can be read
-- local packetLength = bsocket:unpack('i') -- Read the four bytess
-- if bsocket:canRead(packetLength) then
-- -- ...continue reading packet values
BufferedReader = {
new = function(self, socket, readBuffer)
local o = {}
setmetatable(o, self)
self.__index = self
o.readBuffer = readBuffer -- May be nil
o.pos = 1
o.socket = socket -- May also be nil
return o
end,
---
-- This method blocks until the specified number of bytes
-- have been read from the socket and are avaiable for
-- the caller to read, e.g via the unpack function
canRead= function(self,count)
local status, data
self.readBuffer = self.readBuffer or ""
local missing = self.pos + count - #self.readBuffer -1
if ( missing > 0) then
if self.socket == nil then
return doh("Not enough data in static buffer")
end
status, data = self.socket:receive_bytes( missing )
if ( not(status) ) then
return false, data
end
self.readBuffer = self.readBuffer .. data
end
-- Now and then, we flush the buffer
if ( self.pos > 1024) then
self.readBuffer = self.readBuffer:sub( self.pos )
self.pos = 1
end
return true
end,
---
--@return Returns the number of bytes already available for reading
bufferSize = function(self)
return #self.readBuffer +1 -self.pos
end,
---
-- This function works just like bin.unpack (in fact, it is
-- merely a wrapper around it. However, it uses the data
-- already read into the buffer, and the internal position
--@param format - see bin
--@return the unpacked value (NOT the index)
unpack = function(self,format)
local ret = {bin.unpack(format, self.readBuffer, self.pos)}
self.pos = ret[1]
return table.unpack(ret,2)
end,
---
-- This function works just like bin.unpack (in fact, it is
-- merely a wrapper around it. However, it uses the data
-- already read into the buffer, and the internal position.
-- This method does not update the current position, and the
-- data can be read again
--@param format - see bin
--@return the unpacked value (NOT the index)
peekUnpack = function(self,format)
local ret = {bin.unpack(format, self.readBuffer, self.pos)}
return table.unpack(ret,2)
end,
---
-- Tries to read a byte, without consuming it.
--@return status
--@return bytevalue
peekByte = function(self)
if self:canRead(1) then
return true, self:peekUnpack('C')
end
return false
end,
---
-- Skips a number of bytes
--@param len the number of bytes to skip
skip = function(self, len)
if(#self.readBuffer < len + self.pos) then
return doh("ERROR: reading too far ahead")
end
local skipped = self.readBuffer:sub(self.pos, self.pos+len-1)
self.pos = self.pos + len
return true, skipped
end,
}
-- The classes are generated when this file is loaded, by the definitions in the JavaTypes
-- table. That table contains mappings between the format used by bin and the types
-- available in java, aswell as the lengths (used for availability-checks) and the name which
-- is prefixed by read* or write* when monkey-patching the classes and adding functions.
-- For example: {name = 'Int', expr = '>i', len= 4}, will generate the functions
-- writeInt(self, value) and readInt() respectively
local JavaTypes = {
{name = 'Int', expr = '>i', len= 4},
{name = 'UnsignedInt', expr = '>I', len= 4},
{name = 'Short', expr = '>s', len= 2},
{name = 'UnsignedShort', expr = '>S', len= 2},
{name = 'Long', expr = '>l', len= 8},
{name = 'UnsignedLong', expr = '>L', len= 8},
{name = 'Byte', expr = '>C', len= 1},
}
---
-- The JavaDOS classes
-- The JavaDOS class is an approximation of a java DataOutputStream. It provides convenience functions
-- for writing java types toan underlying BufferedWriter
--
-- When used in conjunction with the BufferedX- classes, they handle the availability-
-- checks transparently, i.e the caller does not have to check if enough data is available
--
-- @usage:
-- local dos = JavaDOS:new(BufferedWriter:new(socket))
-- local dos = JavaDIS:new(BufferedReader:new(socket))
-- dos:writeUTF("Hello world")
-- dos:writeInt(3)
-- dos:writeLong(3)
-- dos:flush() -- send data
-- local answer = dis:readUTF()
-- local int = dis:readInt()
-- local long = dis:readLong()
JavaDOS = {
new = function (self,bWriter)
local o = {} -- create new object if user does not provide one
setmetatable(o, self)
self.__index = self -- DIY inheritance
o.bWriter = bWriter
return o
end,
-- This closure method generates all writer methods on the fly
-- according to the definitions in JavaTypes
_generateWriterFunc = function(self, javatype)
local functionName = 'write'..javatype.name
local newFunc = function(_self, value)
--dbg(functionName .."(%s) called" ,tostring(value))
return _self:pack(javatype.expr, value)
end
self[functionName] = newFunc
end,
writeUTF = function(self, text)
-- TODO: Make utf-8 of it
return self:pack('>P', text)
end,
pack = function(self, ...)
local arg={...}
return self.bWriter:pack(table.unpack(arg))
end,
write = function(self, data)
return self.bWriter:send(data)
end,
flush = function(self)
return self.bWriter:flush()
end,
}
---
-- The JavaDIS class
-- JavaDIS is close to java DataInputStream. It provides convenience functions
-- for reading java types from an underlying BufferedReader
--
-- When used in conjunction with the BufferedX- classes, they handle the availability-
-- checks transparently, i.e the caller does not have to check if enough data is available
--
-- @usage:
-- local dos = JavaDOS:new(BufferedWriter:new(socket))
-- local dos = JavaDIS:new(BufferedReader:new(socket))
-- dos:writeUTF("Hello world")
-- dos:writeInt(3)
-- dos:writeLong(3)
-- dos:flush() -- send data
-- local answer = dis:readUTF()
-- local int = dis:readInt()
-- local long = dis:readLong()
JavaDIS = {
new = function (self,bReader)
local o = {} -- create new object if user does not provide one
setmetatable(o, self)
self.__index = self -- DIY inheritance
o.bReader = bReader
return o
end,
-- This closure method generates all reader methods (except unstandard ones) on the fly
-- according to the definitions in JavaTypes.
_generateReaderFunc = function(self, javatype)
local functionName = 'read'..javatype.name
local newFunc = function(_self)
--dbg(functionName .."() called" )
if not _self.bReader:canRead(javatype.len) then
local err = ("Not enough data in buffer (%d required by %s)"):format(javatype.len, functionName)
return doh(err)
end
return true, _self.bReader:unpack(javatype.expr)
end
self[functionName] = newFunc
end,
-- This is a bit special, since we do not know beforehand how many bytes must be read. Therfore
-- this cannot be generated on the fly like the others.
readUTF = function(self, text)
-- First, we need to read the length, 2 bytes
if not self.bReader:canRead(2) then-- Length of the string is two bytes
return false, "Not enough data in buffer [0]"
end
-- We do it as a 'peek', so bin can reuse the data to unpack with 'P'
local len = self.bReader:peekUnpack('>S')
--dbg("Reading utf, len %d" , len)
-- Check that we have data
if not self.bReader:canRead(len) then
return false, "Not enough data in buffer [1]"
end
-- For some reason, the 'P' switch does not work for me.
-- Probably some idiot thing. This is a hack:
local val = self.bReader.readBuffer:sub(self.bReader.pos+2, self.bReader.pos+len+2-1)
self.bReader.pos = self.bReader.pos+len+2
-- Someone smarter than me can maybe get this working instead:
--local val = self.bReader:unpack('P')
--dbg("Read UTF: %s", val)
return true, val
end,
readLongAsHexString = function(self)
if not self.bReader:canRead(8) then-- Length of the string is two bytes
return false, "Not enough data in buffer [3]"
end
return true, self.bReader:unpack('H8')
end,
skip = function(self, len)
return self.bReader:skip(len)
end,
canRead = function(self, len)
return self.bReader:canRead(len)
end,
}
-- Generate writer-functions on the JavaDOS/JavaDIS classes on the fly
for _,x in ipairs(JavaTypes) do
JavaDOS._generateWriterFunc(JavaDOS, x)
JavaDIS._generateReaderFunc(JavaDIS, x)
end
---
-- This class represents a java class and is what is returned by the library
-- when invoking a remote function. Therefore, this can also represent a java
-- object instance.
JavaClass = {
new = function(self)
local o = {}
setmetatable(o, self)
self.__index = self
return o
end,
customDataFormatter = nil,
setName = function( self, name )
dbg("Setting class name to %s", name)
self.name = name
end,
setSerialID = function( self, serial ) self.serial = serial end,
setFlags = function( self, flags )
self.flags = RMIUtils.flagsToString(flags)
self._binaryflags = flags
end,
isExternalizable = function(self)
if self._binaryFlags == nil then return false end
return bit.band(self._binaryflags, RMIUtils.SC_EXTERNALIZABLE)
end,
addField = function( self, field )
if self.fields == nil then self.fields = {} end
table.insert( self.fields, field )
--self[field.name] = field
end,
setSuperClass = function(self,super) self.superClass = super end,
setCustomData = function(self, data) self.customData = data end,
getCustomData = function(self) return self.customData end,
setInterfaces = function(self,ifaces) self.ifaces = ifaces end,
getName = function( self ) return self.name end,
getSuperClass = function(self) return self.superClass end,
getSerialID = function( self ) return self.serial end,
getFlags = function( self ) return self.flags end,
getFields = function( self ) return self.fields end,
getFieldByName = function( self, name )
if self.fields == nil then return end
for i=1, #self.fields do
if ( self.fields[i].name == name ) then
return self.fields[i]
end
end
end,
__tostring = function( self )
local data
if self.name ~=nil then
data = ("%s "):format(self.name)
else
data = "???"
end
if self.superClass~=nil then
data = data .. " extends ".. tostring( self.superClass)
end
if self.ifaces ~= nil then
data = data .. " implements " .. self.ifaces
end
if self.fields ~=nil then
for i=1, #self.fields do
if i == 1 then
data = data .. "["
end
data = data .. tostring(self.fields[i])
if ( i < #self.fields ) then
data = data .. ";"
else
data = data .. "]"
end
end
end
return data
end,
toTable = function(self, customDataFormatter)
local data = {self.name}
if self.externalData ~=nil then
table.insert(data, tostring(self.externalData))
end
--if self.name ~=nil then
-- data.class = self.name
--end
if self.ifaces ~= nil then
table.insert(data, " implements " .. self.ifaces)
end
if self.superClass~=nil then
local extends = self.superClass:toTable()
table.insert(data ,"extends")
table.insert(data, extends)
--data.extends = self.superClass:toTable()
end
if self.fields ~=nil then
table.insert(data, "fields")
local f = {}
for i=1, #self.fields do
table.insert(f, self.fields[i]:toTable())
end
table.insert(data, f)
end
if self.customData ~=nil then
local formatter = JavaClass['customDataFormatter']
if formatter ~= nil then
local title, cdata = formatter(self.name, self.customData)
table.insert(data, title)
table.insert(data, cdata)
else
table.insert(data, "Custom data")
table.insert(data, self.customData)
end
end
return data
end,
}
--- Represents a field in an object, i.e an object member
JavaField = {
new = function(self, name, typ )
local o = {}
setmetatable(o, self)
self.__index = self
o.name = name
o.type = typ
return o
end,
setType = function( self, typ ) self.type = typ end,
setSignature = function( self, sig ) self.signature = sig end,
setName = function( self, name ) self.name = name end,
setObjectType = function( self, ot ) self.object_type = ot end,
setReference = function( self, ref ) self.ref = ref end,
setValue = function (self, val)
dbg("Setting field value to %s", tostring(val))
self.value = val
end,
getType = function( self ) return self.type end,
getSignature = function( self ) return self.signature end,
getName = function( self ) return self.name end,
getObjectType = function( self ) return self.object_type end,
getReference = function( self ) return self.ref end,
getValue = function( self ) return self.value end,
__tostring = function( self )
local data = tostring(self.type) .. " " .. tostring(self.name)
if self.value ~= nil then
data = data .." = " .. tostring(self.value)
end
return data
end,
toTable = function(self)
local data = {tostring(self.type) .. " " .. tostring(self.name)}
--print("FIELD VALUE:", self.value)
if self.value ~= nil then
if type(self.value) == 'table' then
if self.value.toTable ~=nil then
table.insert(data, self.value:toTable())
else
table.insert(data, self.value)
end
else
data = data .." = " .. tostring(self.value)
end
end
return data
end,
}
---
-- Represents a java array. Internally, this is a lua list of JavaClass-instances
JavaArray = {
new = function(self)
local o = {}
setmetatable(o, self)
self.__index = self
o.values = {}
return o
end,
setClass = function( self, class ) self.class = class end,
setLength = function( self, length ) self.length = length end,
setValue = function(self, index, object) self.values[index] = object end,
__tostring=function(self)
local data = ("Array: %s [%d] = {"):format(tostring(self.class), self.length)
for i=1, #self.values do
data = data .. self.values[i]..","
end
data = data .."}"
return data
end,
toTable = function(self)
local title = ("Array: %s [%d] = {"):format(tostring(self.class), self.length)
local t = {title = self.values}
return t
end,
getValues = function(self) return self.values end
}
TC = {
TC_NULL = 0x70,
TC_REFERENCE = 0x71,
TC_CLASSDESC = 0x72,
TC_OBJECT = 0x73,
TC_STRING = 0x74,
TC_ARRAY = 0x75,
TC_CLASS = 0x76,
TC_BLOCKDATA = 0x77,
TC_ENDBLOCKDATA = 0x78,
TC_RESET = 0x79,
TC_BLOCKDATALONG = 0x7A,
TC_EXCEPTION = 0x7B,
TC_LONGSTRING = 0x7C,
TC_PROXYCLASSDESC = 0x7D,
TC_ENUM = 0x7E,
Integer = 0x49,
Object = 0x4c,
Strings = {
[0x49] = "Integer",
[0x4c] = "Object",
[0x71] = "TC_REFERENCE",
[0x70] = "TC_NULL",
[0x71] = "TC_REFERENCE",
[0x72] = "TC_CLASSDESC",
[0x73] = "TC_OBJECT",
[0x74] = "TC_STRING",
[0x75] = "TC_ARRAY",
[0x76] = "TC_CLASS",
[0x77] = "TC_BLOCKDATA",
[0x78] = "TC_ENDBLOCKDATA",
[0x79] = "TC_RESET",
[0x7A] = "TC_BLOCKDATALONG",
[0x7B] = "TC_EXCEPTION",
[0x7C] = "TC_LONGSTRING",
[0x7D] = "TC_PROXYCLASSDESC",
[0x7E] = "TC_ENUM",
},
}
local Version= 0x02
local Proto= {Stream=0x4b, SingleOp=0x4c, Multiplex=0x4d}
---
-- RmiDataStream class
-- This class can handle reading and writing JRMP, i.e RMI wire protocol and
-- can do some very limited java deserialization. This implementation has
-- borrowed from OpenJDK RMI implementation, but only implements an
-- absolute minimum of what is required in order to perform some basic calls
--
RmiDataStream = {
new = function (self,o)
o = o or {} -- create object if user does not provide one
setmetatable(o, self)
self.__index = self -- DIY inheritance
return o
end,
}
-- An output stream in RMI consists of transport Header information followed by a sequence of Messages.
-- Out:
-- Header Messages
-- HttpMessage
-- Header:
-- 0x4a 0x52 0x4d 0x49 Version Protocol
-- (4a 52 4d 49 === JRMI)
-- Version:
-- 0x00 0x01
-- Protocol:
-- StreamProtocol
-- SingleOpProtocol
-- MultiplexProtocol
-- StreamProtocol:
-- 0x4b
-- SingleOpProtocol:
-- 0x4c
-- MultiplexProtocol:
-- 0x4d
-- Messages:
-- Message
-- Messages Message
----
-- Connects to a remote service. The connection process creates a
-- socket and does some handshaking. If this is successfull,
-- we are definitely talking to an RMI service.
function RmiDataStream:connect(host, port)
local status, err
local socket = nmap.new_socket()
socket:set_timeout(5000)
-- local bsocket = BufferedSocket:new()
socket:connect(host,port, "tcp")
-- Output and input
local dos = JavaDOS:new(BufferedWriter:new(socket))
local dis = JavaDIS:new(BufferedReader:new(socket))
-- Start sending a message --
-- Add Header, Version and Protocol
--dos:write('JRMI' .. bin.pack('H', Version .. Proto.Stream))
dos:writeInt(1246907721) -- == JRMI
dos:writeShort(Version)
dos:writeByte(Proto.Stream)
status = dos:flush()
if not status then
return doh(err)
end
-- For the StreamProtocol and the MultiplexProtocol, the server must respond with a a byte 0x4e
-- acknowledging support for the protocol, and an EndpointIdentifier that contains the host name
-- and port number that the server can see is being used by the client.
-- The client can use this information to determine its host name if it is otherwise unable to do that for security reasons.
-- Read ack
status, err = self:readAck(dis)
if not status then
return doh("No ack received from server:" .. tostring(err))
end
-- The client must then respond with another EndpointIdentifier that contains the clients
-- default endpoint for accepting connections. This can be used by a server in the MultiplexProtocol case to identify the client.
dos:writeUTF("127.0.0.1") -- TODO, write our own ip instead (perhaps not necessary, since we are not using MultiplexProtocol
dos:writeInt(0) -- Port ( 0 works fine)
dos:flush()
self.dos = dos
self.dis =dis
return true
end
-- Reads a DgcAck message, which is sent during conection handshake
--@param dis - a JavaDIS to read from
--@return status
--@return error message
function RmiDataStream:readAck(dis)
local status, ack = dis:readByte()
if not status then return doh( "Could not read data") end
if ack ~= 78 then
return doh("No ack received: ".. tostring(ack))
end
local status, host = dis:readUTF()
if not status then return false, "Could not read data" end
local status, port = dis:readUnsignedInt()
if not status then return false, "Could not read data" end
dbg("RMI-Ack received (host %s, port: %d) " , host, port)
return true
end
-- Sends an RMI method call
--@param out - a JavaDos outputstream
--@param objNum -object id (target of call)
--@param hash - the hashcode for the class that is invoked
--@param op - the operation number (method) invoked
--@param arguments - optional, if arguments are needed to this method. Should be an Arguments table
-- or something else which has a getData() function to get binary data
function RmiDataStream:writeMethodCall(out,objNum, hash, op, arguments)
dbg("Invoking object %s, hash %s, opNum %s, args %s", tostring(objNum), tostring(hash), tostring(op), tostring(arguments))
local dos = self.dos
local dis = self.dis
-- Send Call:
dos:writeByte(0x50)
-- Send Magic 0xaced
dos:writeShort(0xACED)
-- Send version 0x0005
dos:writeShort(0x0005)
-- Send TC_BLOKDATA
dos:writeByte(0x77)
-- send length (byte)
dos:writeByte(0x22)
-- From sun.rmi.transport.StreamRemoteCall :
-- // write out remote call header info...
-- // call header, part 1 (read by Transport)
-- conn.getOutputStream().write(TransportConstants.Call);
-- getOutputStream(); // creates a MarshalOutputStream
-- id.write(out); // object id (target of call)
-- // call header, part 2 (read by Dispatcher)
-- out.writeInt(op); // method number (operation index)
-- out.writeLong(hash); // stub/skeleton hash
-- Send rest of the call
local unique, time, count =0,0,0
dos:writeLong(objNum);-- id objNum
dos:writeInt(unique); -- space
dos:writeLong(time);
dos:writeShort(count);
dos:writeInt(op)
dos:pack('H',hash)
-- And now, the arguments
if arguments ~= nil then
dos:write(arguments:getData())
end
dos:flush()
end
---
-- Invokes a method over RMI
--@param methodData, a table which should contain the following
--@param objNum -object id (target of call)
--@param hash - the hashcode for the class that is invoked
--@param op - the operation number (method) invoked
--@param arguments - optional, if arguments are needed to this method. Should be an Arguments table
-- or something else which has a getData() function to get binary data
--@return status
--@return a JavaClass instance
function RmiDataStream:invoke(objNum, hash, op, arguments)
local status, data
local out = self.out
local dis = self.dis
self:writeMethodCall(out,objNum,hash, op, arguments)
local status, retByte = dis:readByte()
if not status then return false, "No return data received from server" end
if 0x51 ~= retByte then -- 0x51 : Returndata
return false, "No return data received from server"
end
status, data = self:readReturnData(dis)
return status, data
end
---
-- Reads an RMI ReturnData packet
--@param dis a JavaDIS inputstream
function RmiDataStream:readReturnData(dis)
--[[
From -http://turtle.ee.ncku.edu.tw/docs/java/jdk1.2.2/guide/rmi/spec/rmi-protocol.doc3.html :
A ReturnValue of an RMI call consists of a return code to indicate either a normal or
exceptional return, a UniqueIdentifier to tag the return value (used to send a DGCAck if necessary)
followed by the return result: either the Value returned or the Exception thrown.
CallData: ObjectIdentifier Operation Hash (Arguments)
ReturnValue:
0x01 UniqueIdentifier (Value)
0x02 UniqueIdentifier Exception
ObjectIdentifier: ObjectNumber UniqueIdentifier
UniqueIdentifier: Number Time Count
Arguments: Value Arguments Value
Value: Object Primitive
Example: [ac ed][00 05][77][0f][01][25 14 95 21][00 00 01 2b 16 9a 62 5a 80 0b]
[magc][ver ][BL][L ][Ok][ --------------- not interesting atm ----------------------]
--]]
-- We need to be able to read at least 7 bytes
-- If that is doable, we can ignore the status on the following readbyte operations
if not dis:canRead(7) then
return doh("Not enough data received")
end
local status, magic = dis:readShort() -- read magic
local status, version = dis:readShort() -- read version
local status, typ = dis:readByte()
if typ ~= TC.TC_BLOCKDATA then
return doh("Expected block data when reading return data")
end
local status, len = dis:readByte() -- packet length
--dis:setReadLimit(len)
local status, ex = dis:readByte() -- 1=ok, 2=exception thrown
if ex ~= 1 then
return doh("Remote call threw exception")
end
-- We can skip the rest of this block
dis:skip(len -1)
-- Now, the return value object:
local status, x = readObject0(dis)
dbg("Read object, got %d left in buffer", dis.bReader:bufferSize())
if(dis.bReader:bufferSize() > 0) then
local content = dis.bReader:unpack('H'..tostring(dis.bReader:bufferSize()))
dbg("Buffer content: %s" ,content)
end
return status, x
end
---
-- Deserializes a serialized java object
function readObject0(dis)
local finished = false
local data, status, responseType
status, responseType = dis:readByte()
if not status then
return doh("Not enough data received")
end
dbg("Reading object of type : %s" , RMIUtils.tcString(responseType))
local decoder = TypeDecoders[responseType]
if decoder ~= nil then
status, data = decoder(dis)
if not status then return doh("readObject0: Could not read data %s", tostring(data)) end
dbg("Read: %s", tostring(data))
return true, data
else
return doh("No decoder found for responsetype: %s" , RMIUtils.tcString(responseType))
end
end
function readString(dis)
return dis:readUTF()
end
-- Reads return type array
function readArray(dis)
local array = JavaArray:new()
dbg("Reading array class description")
local status, classDesc = readClassDesc(dis)
array:setClass(classDesc)
dbg("Reading array length")
local status, len = dis:readInt()
if not status then
return doh("Could not read data")
end
array:setLength(len)
dbg("Reading array of length is %X", len)
for i =1, len, 1 do
local status, object = readObject0(dis)
array:setValue(i,object)
end
return true, array
end
function readClassDesc(dis)
local status, p = dis:readByte()
if not status then return doh( "Could not read data" ) end
dbg("reading classdesc: %s" , RMIUtils.tcString(p))
local val
if p == TC.TC_CLASSDESC then
dbg("Reading TC_CLASSDESC")
status, val = readNonProxyDesc(dis)
elseif p == TC.TC_NULL then
dbg("Reading TC_NULL")
status, val = true, nil
elseif p == TC.TC_PROXYCLASSDESC then
dbg("Reading TC_PROXYCLASSDESC")
status, val = readProxyDesc(dis)
else
return doh("TC_classdesc is other %d", p)
end
if not status then
return doh("Error reading class description")
end
return status, val
end
function readOrdinaryObject(dis)
local status, desc = readClassDesc(dis)
if not status then
return doh("Error reading ordinary object")
end
if desc:isExternalizable() then
dbg("External content")
local status, extdata = readExternalData(dis)
if status then
desc["externalData"] = extdata
end
else
dbg("Serial content")
local status, serdata = readExternalData(dis)
if status then
desc["externalData"] = serdata
local status, data =parseExternalData(desc)
if status then
desc['externalData'] = data
end
end
end
return status, desc
end
-- Attempts to read some object-data, at least remove the block
-- header. This method returns the external data in 'raw' form,
-- since it is up to each class to define an readExternal method
function readExternalData(dis)
local data = {}
while dis.bReader:bufferSize() > 0 do
local status, tc= dis:readByte()
if not status then
return doh("Could not read external data")
end
dbg("readExternalData: %s", RMIUtils.tcString(tc))
local status, len, content
if tc == TC.TC_BLOCKDATA then
status, len = dis:readByte()
status, content = dis.bReader:skip(len)
--print(bin.unpack("H"..tostring(#content),content))
--print(makeStringReadable(content))
dbg("Read external data (%d bytes): %s " ,len, content)
--local object = ExternalClassParsers['java.rmi.server.RemoteObject'](dis)
--print(object)
return status, content
elseif tc == TC.TC_BLOCKDATALONG then
status, len = dis:readUnsignedInt()
status, content = dis.bReader:skip(len)
return status, content
elseif tc == TC.TC_ENDBLOCKDATA then
--noop
else
return doh("Got unexpected field in readExternalData: %s ", RMIUtils.tcString(tc))
end
end
end
----
-- ExternalClassParsers : External Java Classes
-- This 'class' contains information about certain specific java classes,
-- such as UnicastRef, UnicastRef2. After such an object has been read by
-- the object serialization protocol, it will contain a lump of data which is
-- in 'external' form, and needs to be read in a way which is specific for the class
-- itself. This class contains the implementations for reading out the
-- 'goodies' of e.g UnicastRef, which contain important information about
-- where another RMI-socket is listening and waiting for someone to connect.
ExternalClassParsers = {
---
--@see sun.rmi.transport.tcp.TCPEndpoint
--@see sun.rmi.server.UnicastRef
--@see sun.rmi.server.UnicastRef2
UnicastRef = function(dis)
local stat, host = dis:readUTF();
if not stat then return doh("Parsing external data, could not read host (UTF)") end
local status, port = dis:readUnsignedInt();
if not stat then return doh("Parsing external data, could not read port (int)") end
dbg("a host: %s, port %d", host, port)
return true, ("@%s:%d"):format(host,port)
end,
---
--@see sun.rmi.transport.tcp.TCPEndpoint
--@see sun.rmi.server.UnicastRef
--@see sun.rmi.server.UnicastRef2
UnicastRef2 = function(dis)
local stat, form = dis:readByte();
if not stat then return doh("Parsing external data, could not read byte") end
if form == 0 or form == 1 then-- FORMAT_HOST_PORT or FORMAT_HOST_PORT_FACTORY
local stat, host = dis:readUTF();
if not stat then return doh("Parsing external data, could not read host (UTF)") end
local status, port = dis:readUnsignedInt();
if not stat then return doh("Parsing external data, could not read port (int)") end
dbg("b host: %s, port %d", host, port)
if form ==0 then
return true, ("@%s:%d"):format(host,port)
end
-- for FORMAT_HOST_PORT_FACTORY, there's an object left to read
local status, object = readObject0(dis)
return true, ("@%s:%d"):format(host,port)
--return true, {host = host, port = port, factory = object}
else
return doh("Invalid endpoint format")
end
end
}
--@see java.rmi.server.RemoteObject:readObject()
ExternalClassParsers['java.rmi.server.RemoteObject'] = function(dis)
local status, refClassName = dis:readUTF()
if not status then return doh("Parsing external data, could not read classname (UTF)") end
if #refClassName == 0 then
local status, ref = readObject0(dis)
return status, ref
end
dbg("Ref class name: %s ", refClassName)
local parser = ExternalClassParsers[refClassName]
if parser == nil then
return doh("No external class reader for %s" , refClassName)
end
local status, object = parser(dis)
return status, object
end
-- Attempts to parse the externalized data of an object.
--@return status, the object data
function parseExternalData(j_object)
if j_object == nil then
return doh("parseExternalData got nil object")
end
local className = j_object:getName()
-- Find parser for the object, move up the hierarchy
local obj = j_object
local parser = nil
while(className ~= nil) do
parser = ExternalClassParsers[className]
if parser ~= nil then break end
obj = obj:getSuperClass()
if obj== nil then break end-- No more super classes
className = obj:getName()
end
if parser == nil then
return doh("External reader for class %s is not implemented", tostring(className))
end
-- Read the actual object, start by creating a new dis based on the data-string
local dis = JavaDIS:new(BufferedReader:new(nil,j_object.externalData))
local status, object = parser(dis)
if not status then
return doh("Could not parse external data")
end
return true, object
end
-- Helper function to display data
-- returns the string with all non-printable chars
-- coded as hex
function makeStringReadable(data)
local r = ""
for i=1,#data,1 do
local x = data:byte(i)
if x > 31 and x <127 then
r = r .. data:sub(i,i)
else
r = r .. ("\\x%x"):format(x)
end
end
return r
end
function readNonProxyDesc(dis)
dbg("-- entering readNonProxyDesc--")
local j_class = JavaClass:new()
local status, classname = dis:readUTF()
if not status then return doh( "Could not read data" ) end
j_class:setName(classname)
local status, serialID = dis:readLongAsHexString()
if not status then return doh("Could not read data") end
j_class:setSerialID(serialID)
dbg("Set serial ID to %s", tostring(serialID))
local status, flags = dis:readByte()
if not status then return doh("Could not read data") end
j_class:setFlags(flags)
local status, fieldCount = dis:readShort()
if not status then return doh( "Could not read data") end
dbg("Fieldcount %d", fieldCount)
local fields = {}
for i =0, fieldCount-1,1 do
local status, fieldDesc = readFieldDesc(dis)
j_class:addField(fieldDesc)
-- Need to store in list, the field values need to be read
-- after we have finished reading the class description
-- hierarchy
table.insert(fields,fieldDesc)
end
local status, customStrings = skipCustomData(dis)
if status and customStrings ~= nil and #customStrings > 0 then
j_class:setCustomData(customStrings)
end
local _,superDescriptor = readClassDesc(dis)
j_class:setSuperClass(superDescriptor)
dbg("Superclass read, now reading %i field values", #fields)
--Read field values
for i=1, #fields, 1 do
local status, fieldType = dis:readByte()
local value = nil
if ( TypeDecoders[fieldType] ) then
status, value= TypeDecoders[fieldType](dis)
else
dbg("ellol reading".. RMIUtils.tcString(fieldType))
return
end
dbg("Read fieldvalue ".. tostring(value) .. " for field ".. tostring(fields[i]))
fields[i]:setValue(value)
end
dbg("-- leaving readNonProxyDesc--")
return true, j_class
end
function readProxyDesc(dis)
dbg("-- in readProxyDesc--")
local interfaces = ''
local superclass = nil
local status, ifaceNum= dis:readInt()
if not status then return doh("Could not read data") end
--dbg("# interfaces: %d" , ifaceNum)
while ifaceNum > 0 do
local status, iface = dis:readUTF()
if not status then return doh( "Could not read data") end
--table.insert(interfaces, iface)
interfaces = interfaces .. iface ..', '
dbg("Interface: %s " ,iface)
ifaceNum = ifaceNum-1
end
local j_class = JavaClass:new()
local status, customStrings = skipCustomData(dis)
if status and customStrings ~= nil and #customStrings > 0 then
j_class:setCustomData(customStrings)
end
local _,superDescriptor = readClassDesc(dis)
--print ("superdescriptor", superDescriptor)
j_class:setSuperClass(superDescriptor)
j_class:setInterfaces(interfaces)
dbg("-- leaving readProxyDesc--")
return true, j_class
end
--
-- Skips over all block data and objects until TC_ENDBLOCKDATA is
-- encountered.
-- @see java.io.ObjectInputStream.skipCustomData()
--@return status
--@return any strings found while searching
function skipCustomData(dis)
-- If we come across something interesting, just put it into
-- the returnData list
local returnData = {}
while true do
local status, p = dis:readByte()
if not status then
return doh("Could not read data")
end
if not status then return doh("Could not read data") end
dbg("skipCustomData read %s", RMIUtils.tcString(p))
if p == TC.TC_BLOCKDATA or p == TC.TC_BLOCKDATALONG then
dbg("continuing")
--return
elseif p == TC.TC_ENDBLOCKDATA then
return true, returnData
else
-- In the java impl, this is a function called readObject0. We just
-- use the read null, otherwise error
if p == TC.TC_NULL then
-- No op, already read the byte, continue reading
elseif p == TC.TC_STRING then
--dbg("A string is coming!")
local status, str = dis:readUTF()
if not status then
return doh("Could not read data")
end
dbg("Got a string, but don't know what to do with it! : %s",str)
-- Object serialization is a bit messy. I have seen the
-- classpath being sent over a customdata-field, so it is
-- definitely interesting. Quick fix to get it showing
-- is to just stick it onto the object we are currently at.
-- So, just put the string into the returnData and continue
table.insert(returnData, str)
else
return doh("Not implemented in skipcustomData:: %s", RMIUtils.tcString(p))
end
end
end
end
function readFieldDesc(dis)
-- fieldDesc:
-- primitiveDesc
-- objectDesc
-- primitiveDesc:
-- prim_typecode fieldName
-- objectDesc:
-- obj_typecode fieldName className1
-- prim_typecode:
-- `B' // byte
-- `C' // char
-- `D' // double
-- `F' // float
-- `I' // integer
-- `J' // long
-- `S' // short
-- `Z' // boolean
-- obj_typecode:
-- `[` // array
-- `L' // object
local j_field = JavaField:new()
local status, c = dis:readByte()
if not status then return doh("Could not read data") end
local char = string.char(c)
local status, name = dis:readUTF()
if not status then return doh("Could not read data") end
local fieldType = ('primitive type: (%s) '):format(char)
dbg("Fieldtype, char = %s, %s", tostring(fieldType), tostring(char))
if char == 'L' or char == '[' then
-- These also have classname which tells the type
-- on the field
local status, fieldclassname = readTypeString(dis)
if not status then return doh("Could not read data") end
if char == '[s' then
fieldType = fieldclassname .. " []"
else
fieldType = fieldclassname
end
end
if not status then
return false, fieldType
end
dbg("Field description: name: %s, type: %s", tostring(name), tostring(fieldType))
j_field:setType(fieldType)
j_field:setName(name)
-- setType = function( self, typ ) self.type = typ end,
-- setSignature = function( self, sig ) self.signature = sig end,
-- setName = function( self, name ) self.name = name end,
-- setObjectType = function( self, ot ) self.object_type = ot end,
-- setReference = function( self, ref ) self.ref = ref end,
dbg("Created java field:".. tostring(j_field))
return true, j_field
end
function readTypeString(dis)
local status, tc = dis:readByte()
if not status then return doh("Could not read data") end
if tc == TC.TC_NULL then
return true, nil
elseif tc== TC.TC_REFERENCE then
return doh("Not implemented, readTypeString(TC_REFERENCE)");
elseif tc == TC.TC_STRING then
return dis:readUTF()
elseif tc == TC.TC_LONGSTRING then
--TODO, add this (will throw error as is)
return dis:readLongUTF()
end
end
TypeDecoders =
{
[TC.TC_ARRAY] = readArray,
[TC.TC_CLASSDESC] = readClassDesc,
[TC.TC_STRING] = readString,
[TC.TC_OBJECT] = readOrdinaryObject,
}
---
-- Registry
-- Class to represent the RMI Registry.
--@usage:
-- registry = rmi.Registry:new()
-- status, data = registry:list()
Registry ={
new = function (self,host, port)
local o ={} -- create object
setmetatable(o, self)
self.__index = self -- DIY inheritance
-- Hash code for sun.rmi.registry.RegistryImpl_Stub, which we are invoking :
-- hex: 0x44154dc9d4e63bdf , dec: 4905912898345647071
self.hash = '44154dc9d4e63bdf'
-- RmiRegistry object id is 0
self.objId = 0
o.host = host
o.port = port
return o
end
}
-- Connect to the remote registry.
--@return status
--@return error message
function Registry:_handshake()
local out = RmiDataStream:new()
local status, err = out:connect(self.host,self.port)
if not status then
return doh("Registry connection failed: %s", tostring(err))
end
dbg("Registry connection OK "..tostring(out.bsocket) )
self.out = out
return true
end
---
-- List the named objects in the remote RMI registry
--@return status
--@return a table of strings , or error message
function Registry:list()
if not self:_handshake() then
return doh("Handshake failed")
end
-- Method list() is op number 1
return self.out:invoke(self.objId, self.hash,1)
end
---
-- Perform a lookup on an object in the Registry,
-- takes the name which is bound in the registry
-- as argument
--@return status
--@return JavaClass-object
function Registry:lookup(name)
self:_handshake()
-- Method lookup() is op number 2
-- Takes a string as arguments
local a = Arguments:new()
a:addString(name)
return self.out:invoke(self.objId, self.hash,2, a)
end
----
-- Arguments class
-- This class is meant to handle arguments which is sent to a mehtod invoked
-- remotely. It is mean to contain functionality to add java primitive datatypes,
-- such as pushInt, pushString, pushLong etc. All of these are not implemented
-- currently
--@usage: When invoking a remote method
-- use this class in this manner:
-- Arguments a = Arguments:new()
-- a:addString("foo")
-- datastream:invoke{objNum=oid, hash=hash, opNum = opid, arguments=a}
-- ...
--
Arguments = {
new = function (self,o)
o = o or {} -- create object if user does not provide one
setmetatable(o, self)
self.__index = self -- DIY inheritance
-- We use a buffered socket just to be able to use a javaDOS for writing
self.dos = JavaDOS:new(BufferedWriter:new())
return o
end,
addString = function(self, str)
self.dos:writeByte(TC.TC_STRING)
self.dos:writeUTF(str)
end,
addRaw = function(self, str)
self.dos:write(str)
end,
getData = function(self)
local _, res = self.dos:flush()
return res
end
}
---
-- RMIUtils class provides some some codes and definitions from Java
-- There are three types of output messages: Call, Ping and DgcAck.
-- A Call encodes a method invocation. A Ping is a transport-level message
-- for testing liveness of a remote virtual machine.
-- A DGCAck is an acknowledgment directed to a
-- server's distributed garbage collector that indicates that remote objects
-- in a return value from a server have been received by the client.
RMIUtils = {
-- Indicates a Serializable class defines its own writeObject method.
SC_WRITE_METHOD = 0x01,
-- Indicates Externalizable data written in Block Data mode.
SC_BLOCK_DATA = 0x08,
-- Bit mask for ObjectStreamClass flag. Indicates class is Serializable.
SC_SERIALIZABLE = 0x02,
--Bit mask for ObjectStreamClass flag. Indicates class is Externalizable.
SC_EXTERNALIZABLE = 0x04,
--Bit mask for ObjectStreamClass flag. Indicates class is an enum type.
SC_ENUM = 0x10,
flagsToString = function(flags)
local retval = ''
if ( bit.band(flags, RMIUtils.SC_WRITE_METHOD) ~= 0) then
retval = retval .. " WRITE_METHOD"
end
if ( bit.band(flags, RMIUtils.SC_BLOCK_DATA) ~= 0) then
retval = retval .. " BLOCK_DATA"
end
if ( bit.band(flags, RMIUtils.SC_EXTERNALIZABLE) ~= 0) then
retval = retval .. " EXTERNALIZABLE"
end
if ( bit.band(flags, RMIUtils.SC_SERIALIZABLE) ~= 0) then
retval = retval .. " SC_SERIALIZABLE"
end
if ( bit.band(flags, RMIUtils.SC_ENUM) ~= 0) then
retval = retval .. " SC_ENUM"
end
return retval
end,
tcString = function (constant)
local x = TC.Strings[constant] or "Unknown code"
return ("%s (0x%x)"):format(x,tostring(constant))
end,
}
local RMIMessage = {
Call = 0x50,
Ping = 0x52,
DgcAck= 0x54,
}
STREAM_MAGIC = 0xaced
STREAM_VERSION = 5
baseWireHandle = 0x7E0000
return _ENV;
@KyuuKazami