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-rw-r--r--nselib/ospf.lua534
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diff --git a/nselib/ospf.lua b/nselib/ospf.lua
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--- /dev/null
+++ b/nselib/ospf.lua
@@ -0,0 +1,534 @@
+---
+-- A limited OSPF (Open Shortest Path First routing protocol) library, currently supporting IPv4 and the following
+-- OSPF message types: HELLO, DB_DESCRIPTION, LS_REQUEST, LS_UPDATE
+--
+-- The library consists of an OSPF class that contains code to handle OSPFv2 packets.
+--
+-- @author Patrik Karlsson <patrik@cqure.net>
+-- @author Emiliano Ticci <emiticci@gmail.com>
+-- @copyright Same as Nmap--See https://nmap.org/book/man-legal.html
+
+local math = require "math"
+local stdnse = require "stdnse"
+local string = require "string"
+local table = require "table"
+local ipOps = require "ipOps"
+local packet = require "packet"
+_ENV = stdnse.module("ospf", stdnse.seeall)
+
+local have_ssl, openssl = pcall(require, "openssl")
+
+-- The OSPF class.
+OSPF = {
+
+ -- Message Type constants
+ Message = {
+ HELLO = 1,
+ DB_DESCRIPTION = 2,
+ LS_REQUEST = 3,
+ LS_UPDATE = 4,
+ },
+
+ Header = {
+ size = 24,
+ new = function(self, type, area_id, router_id, auth_type, auth_data)
+ local o = {
+ ver = 2,
+ type = type,
+ length = 0,
+ router_id = router_id or 0,
+ area_id = area_id or 0,
+ chksum = 0,
+ auth_type = auth_type or 0,
+ auth_data = auth_data or {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ parse = function(data)
+ local header = OSPF.Header:new()
+ local pos
+ header.ver, header.type, header.length, pos = string.unpack(">BBI2", data)
+ assert( header.ver == 2, "Invalid OSPF version detected")
+
+ header.router_id, header.area_id, header.chksum, header.auth_type, pos
+ = string.unpack(">I4 I4 I2 I2", data, pos)
+
+ -- No authentication
+ if header.auth_type == 0x00 then
+ header.auth_data.password = nil
+ -- Clear text password
+ elseif header.auth_type == 0x01 then
+ header.auth_data.password, pos = string.unpack("c8", data, pos)
+ -- MD5 hash authentication
+ elseif header.auth_type == 0x02 then
+ header.auth_data.keyid, header.auth_data.length, header.auth_data.seq = string.unpack(">BB I4", data, pos+2)
+ local hash = stdnse.tohex(string.sub(data, header.length+1, header.length+1+header.auth_data.length))
+ header.auth_data.hash = hash
+ else
+ -- Shouldn't happen
+ stdnse.debug1("Unknown authentication type %s", header.auth_type)
+ return nil
+ end
+ header.router_id = ipOps.fromdword(header.router_id)
+ return header
+ end,
+
+ --- Sets the OSPF Area ID
+ -- @param areaid Area ID.
+ setAreaID = function(self, areaid)
+ self.area_id = (type(areaid) == "number") and areaid or ipOps.todword(areaid)
+ end,
+
+ --- Sets the OSPF Router ID
+ -- @param router_id Router ID.
+ setRouterId = function(self, router_id)
+ self.router_id = router_id
+ end,
+
+ --- Sets the OSPF Packet length
+ -- @param length Packet length.
+ setLength = function(self, length)
+ self.length = self.size + length
+ end,
+
+ __tostring = function(self)
+ local auth
+ if self.auth_type == 0x00 then
+ auth = string.rep("\0", 8)
+ elseif self.auth_type == 0x01 then
+ auth = self.auth_data.password
+ elseif self.auth_type == 0x02 then
+ auth = string.pack(">I2 BB I4", 0, self.auth_data.keyid, self.auth_data.length, self.auth_data.seq)
+ end
+ local hdr = string.pack(">BB I2 I4 I4 I2 I2",
+ self.ver, self.type,
+ self.length,
+ ipOps.todword(self.router_id),
+ self.area_id,
+ self.chksum,
+ self.auth_type
+ ) .. auth
+ return hdr
+ end,
+
+ },
+
+ Hello = {
+ new = function(self)
+ local o = {
+ header = OSPF.Header:new(OSPF.Message.HELLO),
+ options = 0x02,
+ prio = 0,
+ interval = 10,
+ router_dead_interval = 40,
+ neighbors = {},
+ DR = "0.0.0.0",
+ BDR = "0.0.0.0",
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ --- Adds a neighbor to the list of neighbors.
+ -- @param neighbor IP Address of the neighbor.
+ addNeighbor = function(self, neighbor)
+ table.insert(self.neighbors, neighbor)
+ end,
+
+ --- Sets the OSPF netmask.
+ -- @param netmask Netmask in A.B.C.D
+ setNetmask = function(self, netmask)
+ if netmask then
+ self.netmask = netmask
+ end
+ end,
+
+ --- Sets the OSPF designated Router.
+ -- @param router IP address of the designated router.
+ setDesignatedRouter = function(self, router)
+ if router then
+ self.DR = router
+ end
+ end,
+
+ --- Sets the OSPF backup Router.
+ -- @param router IP Address of the backup router.
+ setBackupRouter = function(self, router)
+ if router then
+ self.BDR = router
+ end
+ end,
+
+ __tostring = function(self)
+ self.neighbors = self.neighbors or {}
+ local function tostr()
+ local data = {
+ string.pack(">I4 I2 BB I4 I4 I4",
+ ipOps.todword(self.netmask),
+ self.interval,
+ self.options, self.prio,
+ self.router_dead_interval,
+ ipOps.todword(self.DR),
+ ipOps.todword(self.BDR))
+ }
+ for _, n in ipairs(self.neighbors) do
+ data[#data+1] = string.pack(">I4", ipOps.todword(n))
+ end
+ data = table.concat(data)
+ self.header:setLength(#data)
+ return tostring(self.header) .. data .. (self.header.auth_data.hash or "")
+ end
+ local data = tostr()
+ if have_ssl and self.header.auth_type == 0x02 then
+ self.header.auth_data.key = self.header.auth_data.key .. string.rep("\0", 16 - #self.header.auth_data.key)
+ self.header.auth_data.hash = openssl.md5(data .. self.header.auth_data.key)
+ else
+ self.header.chksum = packet.in_cksum(data:sub(1,16) .. data:sub(25))
+ end
+ return tostr()
+ end,
+
+ parse = function(data)
+ local hello = OSPF.Hello:new()
+ local pos = OSPF.Header.size + 1
+ hello.header = OSPF.Header.parse(data)
+ assert( #data >= hello.header.length, "OSPF packet too short")
+ hello.netmask, hello.interval, hello.options, hello.prio,
+ hello.router_dead_interval, hello.DR,
+ hello.BDR, pos = string.unpack(">I4 I2 BB I4 I4 I4", data, pos)
+
+ hello.netmask = ipOps.fromdword(hello.netmask)
+ hello.DR = ipOps.fromdword(hello.DR)
+ hello.BDR = ipOps.fromdword(hello.BDR)
+
+ if ( ( #data - pos + 1 ) % 4 ~= 0 ) then
+ stdnse.debug2("Unexpected OSPF packet length, aborting ...")
+ return
+ end
+
+ local neighbor_count = ( hello.header.length - pos + 1 ) / 4
+ local neighbor
+
+ hello.neighbors = {}
+ for i=1, neighbor_count do
+ neighbor, pos = string.unpack(">I4", data, pos)
+ neighbor = ipOps.fromdword(neighbor)
+ table.insert(hello.neighbors, neighbor)
+ end
+ return hello
+ end,
+
+ },
+
+ LSA = {
+ Header = {
+ size = 20,
+ new = function(self)
+ local o = {
+ age = 0,
+ options = 0,
+ type = 1,
+ id = 0,
+ adv_router = 0,
+ sequence = 0,
+ checksum = 0,
+ length = 0,
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ parse = function(data)
+ local lsa_h = OSPF.LSA.Header:new()
+ local pos = 1
+ lsa_h.age, lsa_h.options, lsa_h.type, lsa_h.id, lsa_h.adv_router,
+ lsa_h.sequence, lsa_h.checksum, lsa_h.length, pos = string.unpack(">I2 BB I4 I4 c4 c2 I2", data, pos)
+
+ lsa_h.id = ipOps.fromdword(lsa_h.id)
+ lsa_h.adv_router = ipOps.fromdword(lsa_h.adv_router)
+ lsa_h.sequence = stdnse.tohex(lsa_h.sequence)
+ lsa_h.checksum = stdnse.tohex(lsa_h.checksum)
+ return lsa_h
+ end,
+
+ },
+
+ Link = {
+ new = function(self)
+ local o = {
+ id = 0,
+ data = 0,
+ type = 2,
+ num_metrics = 0,
+ metric = 10,
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ parse = function(data)
+ local lsa_link = OSPF.LSA.Link:new()
+ local pos = 1
+ lsa_link.id, lsa_link.data, lsa_link.type,
+ lsa_link.num_metrics, lsa_link.metric, pos = string.unpack(">I4 I4 BB I2", data, pos)
+ lsa_link.id = ipOps.fromdword(lsa_link.id)
+ lsa_link.data = ipOps.fromdword(lsa_link.data)
+ return lsa_link
+ end,
+ },
+
+ Router = {
+ new = function(self)
+ local o = {
+ header = OSPF.LSA.Header:new(),
+ flags = 0,
+ num_links = 0,
+ links = {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ parse = function(data)
+ local router = OSPF.LSA.Router:new()
+ local pos = OSPF.LSA.Header.size + 1
+ router.header = OSPF.LSA.Header.parse(data)
+ router.flags, router.num_links, pos = string.unpack(">B x I2", data, pos)
+
+ while ( pos < router.header.length ) do
+ table.insert(router.links, OSPF.LSA.Link.parse(data:sub(pos, pos + 12)))
+ pos = pos + 12
+ end
+
+ return router
+ end,
+ },
+
+ ASExternal = {
+ new = function(self)
+ local o = {
+ header = OSPF.LSA.Header:new(),
+ netmask = 0,
+ ext_type = 1,
+ metric = 1,
+ fw_address = 0,
+ ext_tag = 0,
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ parse = function(data)
+ local as_ext = OSPF.LSA.ASExternal:new()
+ local pos = OSPF.LSA.Header.size + 1
+ as_ext.header = OSPF.LSA.Header.parse(data)
+
+ as_ext.netmask, as_ext.metric, as_ext.fw_address, as_ext.ext_tag, pos = string.unpack(">I4 I4 I4 I4", data, pos)
+ as_ext.netmask = ipOps.fromdword(as_ext.netmask)
+ as_ext.ext_type = 1 + ((as_ext.metric & 0xFF000000) >> 31)
+ as_ext.metric = as_ext.metric & 0x00FFFFFF
+ as_ext.fw_address = ipOps.fromdword(as_ext.fw_address)
+
+ return as_ext
+ end,
+ },
+
+ parse = function(data)
+ local header = OSPF.LSA.Header.parse(data)
+ if header.type == 1 then
+ return OSPF.LSA.Router.parse(data)
+ elseif header.type == 5 then
+ return OSPF.LSA.ASExternal.parse(data)
+ end
+ return header.length
+ end,
+ },
+
+ DBDescription = {
+
+ new = function(self)
+ local o = {
+ header = OSPF.Header:new(OSPF.Message.DB_DESCRIPTION),
+ mtu = 1500,
+ options = 2, -- external routing capability
+ init = true,
+ more = true,
+ master = true,
+ sequence = math.random(123456789),
+ lsa_headers = {}
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ __tostring = function(self)
+ local function tostr()
+ local flags = 0
+ if ( self.init ) then flags = flags + 4 end
+ if ( self.more ) then flags = flags + 2 end
+ if ( self.master) then flags= flags + 1 end
+
+ local data = string.pack(">I2 BB I4", self.mtu, self.options, flags, self.sequence)
+ self.header:setLength(#data)
+ return tostring(self.header) .. data .. (self.header.auth_data.hash or "")
+ end
+ local data = tostr()
+ if have_ssl and self.header.auth_type == 0x02 then
+ self.header.auth_data.key = self.header.auth_data.key .. string.rep("\0", 16 - #self.header.auth_data.key)
+ self.header.auth_data.hash = openssl.md5(data .. self.header.auth_data.key)
+ else
+ self.header.chksum = packet.in_cksum(data:sub(1,16) .. data:sub(25))
+ end
+ return tostr()
+ end,
+
+ parse = function(data)
+ local desc = OSPF.DBDescription:new()
+ local pos = OSPF.Header.size + 1
+ desc.header = OSPF.Header.parse(data)
+ assert( #data >= desc.header.length, "OSPF packet too short")
+
+ local flags = 0
+ desc.mtu, desc.options, flags, desc.sequence, pos = string.unpack(">I2 BB I4", data, pos)
+
+ desc.init = (flags & 4) == 4
+ desc.more = (flags & 2) == 2
+ desc.master = (flags & 1) == 1
+
+ while ( pos < desc.header.length ) do
+ table.insert(desc.lsa_headers, OSPF.LSA.Header.parse(data:sub(pos, pos + 20)))
+ pos = pos + 20
+ end
+
+ if ( desc.init or not(desc.more) ) then
+ return desc
+ end
+
+ return desc
+ end,
+
+ },
+
+ LSRequest = {
+ new = function(self)
+ local o = {
+ header = OSPF.Header:new(OSPF.Message.LS_REQUEST),
+ ls_requests = {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ --- Adds a request to the list of requests.
+ -- @param type LS Type.
+ -- @param id Link State ID
+ -- @param adv_router Advertising Router
+ addRequest = function(self, type, id, adv_router)
+ local request = {
+ type = type,
+ id = id,
+ adv_router = adv_router
+ }
+ table.insert(self.ls_requests, request)
+ end,
+
+ __tostring = function(self)
+ local function tostr()
+ local data = {}
+ for _, req in ipairs(self.ls_requests) do
+ data[#data+1] = string.pack(">I4 I4 I4", req.type, ipOps.todword(req.id), ipOps.todword(req.adv_router))
+ end
+ data = table.concat(data)
+ self.header:setLength(#data)
+ return tostring(self.header) .. data .. (self.header.auth_data.hash or "")
+ end
+ local data = tostr()
+ if have_ssl and self.header.auth_type == 0x02 then
+ self.header.auth_data.key = self.header.auth_data.key .. string.rep("\0", 16 - #self.header.auth_data.key)
+ self.header.auth_data.hash = openssl.md5(data .. self.header.auth_data.key)
+ else
+ self.header.chksum = packet.in_cksum(data:sub(1,16) .. data:sub(25))
+ end
+ return tostr()
+ end,
+
+ parse = function(data)
+ local ls_req = OSPF.LSRequest:new()
+ local pos = OSPF.Header.size + 1
+ ls_req.header = OSPF.Header.parse(data)
+ assert( #data >= ls_req.header.length, "OSPF packet too short")
+
+ while ( pos < #data ) do
+ local req = {}
+ req.type, req.id, req.adv_router, pos = string.unpack(">I4 I4 I4", data, pos)
+ table.insert(ls_req.ls_requests, req)
+ end
+
+ return ls_req
+ end,
+ },
+
+ LSUpdate = {
+ new = function(self)
+ local o = {
+ header = OSPF.Header:new(OSPF.Message.LS_UPDATE),
+ num_lsas = 0,
+ lsas = {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ parse = function(data)
+ local lsu = OSPF.LSUpdate:new()
+ local pos = OSPF.Header.size + 1
+ lsu.header = OSPF.Header.parse(data)
+ assert( #data >= lsu.header.length, "OSPF packet too short")
+
+ lsu.num_lsas, pos = string.unpack(">I4", data, pos)
+
+ while ( pos < lsu.header.length ) do
+ local lsa = OSPF.LSA.parse(data:sub(pos))
+ if ( type(lsa) == "table" ) then
+ table.insert(lsu.lsas, lsa)
+ pos = pos + lsa.header.length
+ else
+ pos = pos + lsa
+ end
+ end
+
+ return lsu
+ end,
+ },
+
+ Response = {
+
+ parse = function(data)
+ local ver, ospf_type, pos = string.unpack("BB", data)
+ if ( ospf_type == OSPF.Message.HELLO ) then
+ return OSPF.Hello.parse( data )
+ elseif( ospf_type == OSPF.Message.DB_DESCRIPTION ) then
+ return OSPF.DBDescription.parse(data)
+ elseif( ospf_type == OSPF.Message.LS_REQUEST ) then
+ return OSPF.LSRequest.parse(data)
+ elseif( ospf_type == OSPF.Message.LS_UPDATE ) then
+ return OSPF.LSUpdate.parse(data)
+ end
+ return
+ end,
+
+ }
+}
+
+return _ENV;
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