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Diffstat (limited to '')
| -rw-r--r-- | scripts/broadcast-ospf2-discover.nse | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/scripts/broadcast-ospf2-discover.nse b/scripts/broadcast-ospf2-discover.nse new file mode 100644 index 0000000..ad3fca0 --- /dev/null +++ b/scripts/broadcast-ospf2-discover.nse @@ -0,0 +1,431 @@ +local ipOps = require "ipOps" +local nmap = require "nmap" +local ospf = require "ospf" +local packet = require "packet" +local stdnse = require "stdnse" +local target = require "target" +local os = require "os" +local string = require "string" +local table = require "table" + +local have_ssl, openssl = pcall(require,'openssl') + +description = [[ +Discover IPv4 networks using Open Shortest Path First version 2(OSPFv2) protocol. + +The script works by listening for OSPF Hello packets from the 224.0.0.5 +multicast address. The script then replies and attempts to create a neighbor +relationship, in order to discover network database. + +If no interface was provided as a script argument or through the -e option, +the script will fail unless a single interface is present on the system. +]] + +--- +-- @usage +-- nmap --script=broadcast-ospf2-discover +-- nmap --script=broadcast-ospf2-discover -e wlan0 +-- +-- @args broadcast-ospf2-discover.md5_key MD5 digest key to use if message digest +-- authentication is disclosed. +-- +-- @args broadcast-ospf2-discover.router_id Router ID to use. Defaults to 0.0.0.1 +-- +-- @args broadcast-ospf2-discover.timeout Time in seconds that the script waits for +-- hello from other routers. Defaults to 10 seconds, matching OSPFv2 default +-- value for hello interval. +-- +-- @args broadcast-ospf2-discover.interface Interface to send on (overrides -e). Mandatory +-- if not using -e and multiple interfaces are present. +-- +-- @output +-- Pre-scan script results: +-- | broadcast-ospf2-discover: +-- | Area ID: 0.0.0.0 +-- | External Routes +-- | 192.168.24.0/24 +-- |_ Use the newtargets script-arg to add the results as targets +-- + +author = "Emiliano Ticci" +license = "Same as Nmap--See https://nmap.org/book/man-legal.html" +categories = {"broadcast", "discovery", "safe"} + +prerule = function() + if nmap.address_family() ~= "inet" then + stdnse.print_verbose("is IPv4 only.") + return false + end + if not nmap.is_privileged() then + stdnse.print_verbose("not running for lack of privileges.") + return false + end + return true +end + +-- Script constants +OSPF_ALL_ROUTERS = "224.0.0.5" +OSPF_MSG_HELLO = 0x01 +OSPF_MSG_DBDESC = 0x02 +OSPF_MSG_LSREQ = 0x03 +OSPF_MSG_LSUPD = 0x04 +local md5_key, router_id + +-- Convenience functions +local function fail(err) return stdnse.format_output(false, err) end + +-- Print OSPFv2 LSA Header packet details to debug output. +-- @param hello OSPFv2 LSA Header packet +local ospfDumpLSAHeader = function(lsa_h) + if 2 > nmap.debugging() then + return + end + stdnse.print_debug(2, "| LS Age: %s", lsa_h.age) + stdnse.print_debug(2, "| Options: %s", lsa_h.options) + stdnse.print_debug(2, "| LS Type: %s", lsa_h.type) + stdnse.print_debug(2, "| Link State ID: %s", lsa_h.id) + stdnse.print_debug(2, "| Advertising Router: %s", lsa_h.adv_router) + stdnse.print_debug(2, "| Sequence: 0x%s", lsa_h.sequence) + stdnse.print_debug(2, "| Checksum: 0x%s", lsa_h.checksum) + stdnse.print_debug(2, "| Length: %s", lsa_h.length) +end + +-- Print OSPFv2 Database Description packet details to debug output. +-- @param hello OSPFv2 Database Description packet +local ospfDumpDBDesc = function(db_desc) + if 2 > nmap.debugging() then + return + end + stdnse.print_debug(2, "| MTU: %s", db_desc.mtu) + stdnse.print_debug(2, "| Options: %s", db_desc.options) + stdnse.print_debug(2, "| Init: %s", db_desc.init) + stdnse.print_debug(2, "| More: %s", db_desc.more) + stdnse.print_debug(2, "| Master: %s", db_desc.master) + stdnse.print_debug(2, "| Sequence: %s", db_desc.sequence) + if #db_desc.lsa_headers > 0 then + stdnse.print_debug(2, "| LSA Headers:") + for i, lsa_h in ipairs(db_desc.lsa_headers) do + ospfDumpLSAHeader(lsa_h) + if i < #db_desc.lsa_headers then + stdnse.print_debug(2, "|") + end + end + end +end + +-- Print OSPFv2 Hello packet details to debug output. +-- @param hello OSPFv2 Hello packet +local ospfDumpHello = function(hello) + if 2 > nmap.debugging() then + return + end + stdnse.print_debug(2, "| Router ID: %s", hello.header.router_id) + stdnse.print_debug(2, "| Area ID: %s", ipOps.fromdword(hello.header.area_id)) + stdnse.print_debug(2, "| Checksum: %s", hello.header.chksum) + stdnse.print_debug(2, "| Auth Type: %s", hello.header.auth_type) + if hello.header.auth_type == 0x01 then + stdnse.print_debug(2, "| Auth Password: %s", hello.header.auth_data.password) + elseif hello.header.auth_type == 0x02 then + stdnse.print_debug(2, "| Auth Crypt Key ID: %s", hello.header.auth_data.keyid) + stdnse.print_debug(2, "| Auth Data Length: %s", hello.header.auth_data.length) + stdnse.print_debug(2, "| Auth Crypt Seq: %s", hello.header.auth_data.seq) + end + stdnse.print_debug(2, "| Netmask: %s", hello.netmask) + stdnse.print_debug(2, "| Hello interval: %s", hello.interval) + stdnse.print_debug(2, "| Options: %s", hello.options) + stdnse.print_debug(2, "| Priority: %s", hello.prio) + stdnse.print_debug(2, "| Dead interval: %s", hello.router_dead_interval) + stdnse.print_debug(2, "| Designated Router: %s", hello.DR) + stdnse.print_debug(2, "| Backup Router: %s", hello.BDR) + stdnse.print_debug(2, "| Neighbors: %s", table.concat(hello.neighbors, ",")) +end + +-- Print OSPFv2 LS Request packet details to debug output. +-- @param ls_req OSPFv2 LS Request packet +local ospfDumpLSRequest = function(ls_req) + if 2 > nmap.debugging() then + return + end + for i, req in ipairs(ls_req.ls_requests) do + stdnse.print_debug(2, "| LS Type: %s", req.type) + stdnse.print_debug(2, "| Link State ID: %s", req.id) + stdnse.print_debug(2, "| Avertising Router: %s", req.adv_router) + if i < #ls_req.ls_requests then + stdnse.print_debug(2, "|") + end + end +end + +-- Print OSPFv2 LS Update packet details to debug output. +-- @param ls_upd OSPFv2 LS Update packet +local ospfDumpLSUpdate = function(ls_upd) + stdnse.print_debug(2, "| Number of LSAs: %s", ls_upd.num_lsas) + for i, lsa in ipairs(ls_upd.lsas) do + -- Only Type 1 (Router-LSA) and Type 5 (AS-External-LSA) are supported at the moment + ospfDumpLSAHeader(lsa.header) + if lsa.header.type == 1 then + stdnse.print_debug(2, "| Flags: %s", lsa.flags) + stdnse.print_debug(2, "| Number of links: %s", lsa.num_links) + for j, link in ipairs(lsa.links) do + stdnse.print_debug(2, "| Link ID: %s", link.id) + stdnse.print_debug(2, "| Link Data: %s", link.data) + stdnse.print_debug(2, "| Link Type: %s", link.type) + stdnse.print_debug(2, "| Number of Metrics: %s", link.num_metrics) + stdnse.print_debug(2, "| 0 Metric: %s", link.metric) + if j < #lsa.links then + stdnse.print_debug(2, "|") + end + end + if i < #ls_upd.lsas then + stdnse.print_debug(2, "|") + end + elseif lsa.header.type == 5 then + stdnse.print_debug(2, "| Netmask: %s", lsa.netmask) + stdnse.print_debug(2, "| External Type: %s", lsa.ext_type) + stdnse.print_debug(2, "| Metric: %s", lsa.metric) + stdnse.print_debug(2, "| Forwarding Address: %s", lsa.fw_address) + stdnse.print_debug(2, "| External Route Tag: %s", lsa.ext_tag) + end + end +end + +-- Send OSPFv2 packet to specified destination. +-- @param interface Source interface to use +-- @param ip_dst Destination IP address +-- @param mac_dst Destination MAC address +-- @param ospf_packet Raw OSPF packet +local ospfSend = function(interface, ip_dst, mac_dst, ospf_packet) + local dnet = nmap.new_dnet() + local probe = packet.Frame:new() + + probe.mac_src = interface.mac + probe.mac_dst = mac_dst + probe.ip_bin_src = ipOps.ip_to_str(interface.address) + probe.ip_bin_dst = ipOps.ip_to_str(ip_dst) + probe.l3_packet = ospf_packet + probe.ip_dsf = 0xc0 + probe.ip_p = 89 + probe.ip_ttl = 1 + + probe:build_ip_packet() + probe:build_ether_frame() + + dnet:ethernet_open(interface.device) + dnet:ethernet_send(probe.frame_buf) + dnet:ethernet_close() +end + +-- Prepare OSPFv2 packet header for reply. +-- @param packet_in Source packet +-- @param packet_out Destination packet +local ospfSetHeader = function(packet_in, packet_out) + packet_out.header:setRouterId(router_id) + packet_out.header:setAreaID(packet_in.header.area_id) + if packet_in.header.auth_type == 0x01 then + packet_out.header.auth_type = 0x01 + packet_out.header.auth_data.password = packet_in.header.auth_data.password + elseif packet_in.header.auth_type == 0x02 then + packet_out.header.auth_type = 0x02 + packet_out.header.auth_data.key = md5_key + packet_out.header.auth_data.keyid = packet_in.header.auth_data.keyid + packet_out.header.auth_data.length = 16 + packet_out.header.auth_data.seq = os.time() + end + + return packet_out +end + +-- Reply to OSPFv2 Database Description with an LS Request. +-- @param interface Source interface +-- @param mac_dst Destination MAC address +-- @param db_desc_in OSPFv2 Database Description packet to reply for +local ospfSendLSRequest = function(interface, mac_dst, db_desc_in) + local ls_req_out = ospf.OSPF.LSRequest:new() + ls_req_out = ospfSetHeader(db_desc_in, ls_req_out) + + for i, lsa_h in ipairs(db_desc_in.lsa_headers) do + ls_req_out:addRequest(lsa_h.type, lsa_h.id, lsa_h.adv_router) + end + + stdnse.print_debug(2, "Crafted OSPFv2 LS Request packet with the following parameters:") + ospfDumpLSRequest(ls_req_out) + ospfSend(interface, db_desc_in.header.router_id, mac_dst, tostring(ls_req_out)) +end + +-- Reply to given OSPFv2 Database Description packet. +-- @param interface Source interface +-- @param mac_dst Destination MAC address +-- @param db_desc_in OSPFv2 Database Description packet to reply for +local ospfReplyDBDesc = function(interface, mac_dst, db_desc_in) + local reply = false + local db_desc_out = ospf.OSPF.DBDescription:new() + db_desc_out = ospfSetHeader(db_desc_in, db_desc_out) + + if db_desc_in.init == true then + db_desc_out.init = false + db_desc_out.more = db_desc_in.more + db_desc_out.master = false + db_desc_out.sequence = db_desc_in.sequence + reply = true + elseif #db_desc_in.lsa_headers > 0 then + ospfSendLSRequest(interface, mac_dst, db_desc_in) + return true + end + + if reply then + stdnse.print_debug(2, "Crafted OSPFv2 Database Description packet with the following parameters:") + ospfDumpDBDesc(db_desc_out) + ospfSend(interface, db_desc_in.header.router_id, mac_dst, tostring(db_desc_out)) + end + + return reply +end + +-- Reply to given OSPFv2 Hello packet sending another Hello to +-- "All OSPF Routers" multicast address (224.0.0.5). +-- @param interface Source interface +-- @param hello_in OSPFv2 Hello packet to reply for +local ospfReplyHello = function(interface, hello_in) + local hello_out = ospf.OSPF.Hello:new() + hello_out = ospfSetHeader(hello_in, hello_out) + hello_out.interval = hello_in.interval + hello_out.router_dead_interval = hello_in.router_dead_interval + hello_out:setDesignatedRouter(hello_in.header.router_id) + hello_out:setNetmask(hello_in.netmask) + hello_out:addNeighbor(hello_in.header.router_id) + + stdnse.print_debug(2, "Crafted OSPFv2 Hello packet with the following parameters:") + ospfDumpHello(hello_out) + + ospfSend(interface, OSPF_ALL_ROUTERS, "\x01\x00\x5e\x00\x00\x05", tostring(hello_out)) +end + +-- Listen for OSPF packets on a specified interface. +-- @param interface Interface to use +-- @param timeout Amount of time to listen in seconds +local ospfListen = function(interface, timeout) + local status, l2_data, l3_data, ospf_raw, _ + local start = nmap.clock_ms() + + stdnse.print_debug("Start listening on interface %s...", interface.shortname) + local listener = nmap.new_socket() + listener:set_timeout(1000) + listener:pcap_open(interface.device, 1500, true, "ip proto 89 and not (ip src host " .. interface.address .. ")") + while (nmap.clock_ms() - start) < (timeout * 1000) do + status, _, l2_data, l3_data = listener:pcap_receive() + if status then + stdnse.print_debug(2, "Packet received on interface %s.", interface.shortname) + local p = packet.Packet:new(l3_data, #l3_data) + local ospf_raw = string.sub(l3_data, p.ip_hl * 4 + 1) + if ospf_raw:byte(1) == 0x02 and ospf_raw:byte(2) == OSPF_MSG_HELLO then + stdnse.print_debug(2, "OSPFv2 Hello packet detected.") + + local ospf_hello = ospf.OSPF.Hello.parse(ospf_raw) + stdnse.print_debug(2, "Captured OSPFv2 Hello packet with the following parameters:") + ospfDumpHello(ospf_hello) + + -- Additional checks required for message digest authentication + if ospf_hello.header.auth_type == 0x02 then + if not md5_key then + return fail("Argument md5_key must be present when message digest authentication is disclosed.") + elseif not have_ssl then + return fail("Cannot handle message digest authentication unless openssl is compiled in.") + end + end + + ospfReplyHello(interface, ospf_hello) + start = nmap.clock_ms() + elseif ospf_raw:byte(1) == 0x02 and ospf_raw:byte(2) == OSPF_MSG_DBDESC then + stdnse.print_debug(2, "OSPFv2 Database Description packet detected.") + + local ospf_db_desc = ospf.OSPF.DBDescription.parse(ospf_raw) + stdnse.print_debug(2, "Captured OSPFv2 Database Description packet with the following parameters:") + ospfDumpDBDesc(ospf_db_desc) + + if not ospfReplyDBDesc(interface, string.sub(l2_data, 7, 12), ospf_db_desc) then + return + end + elseif ospf_raw:byte(1) == 0x02 and ospf_raw:byte(2) == OSPF_MSG_LSUPD then + stdnse.print_debug(2, "OSPFv2 LS Update packet detected.") + + local ospf_ls_upd = ospf.OSPF.LSUpdate.parse(ospf_raw) + stdnse.print_debug(2, "Captured OSPFv2 LS Update packet with the following parameters:") + ospfDumpLSUpdate(ospf_ls_upd) + + local targets = {} + for i, lsa in ipairs(ospf_ls_upd.lsas) do + -- Only Type 1 (Router-LSA) and Type 5 (AS-External-LSA) are supported at the moment + if lsa.header.type == 1 then + for j, link in ipairs(lsa.links) do + if link.type == 3 then + local target = link.id .. ipOps.subnet_to_cidr(link.data) + targets[target] = 1 + end + end + elseif lsa.header.type == 5 then + local target = lsa.header.id .. ipOps.subnet_to_cidr(lsa.netmask) + targets[target] = 1 + end + end + local output = stdnse.output_table() + if next(targets) then + local out_links = {} + output["Area ID"] = ipOps.fromdword(ospf_ls_upd.header.area_id) + output["External Routes"] = out_links + for t, _ in pairs(targets) do + table.insert(out_links, t) + if target.ALLOW_NEW_TARGETS then + target.add(t) + end + end + if not target.ALLOW_NEW_TARGETS then + stdnse.verbose("Use the newtargets script-arg to add the results as targets") + end + end + return output + end + end + end + listener:pcap_close() +end + +action = function() + -- Get script arguments + md5_key = stdnse.get_script_args(SCRIPT_NAME .. ".md5_key") or false + router_id = stdnse.get_script_args(SCRIPT_NAME .. ".router_id") or "0.0.0.1" + local timeout = stdnse.parse_timespec(stdnse.get_script_args(SCRIPT_NAME .. ".timeout")) or 10 + local interface = stdnse.get_script_args(SCRIPT_NAME .. ".interface") + stdnse.print_debug("Value for router ID argument: %s.", router_id) + stdnse.print_debug("Value for timeout argument: %s.", timeout) + + -- Determine interface to use + interface = interface or nmap.get_interface() + if interface then + interface = nmap.get_interface_info(interface) + if not interface then + return fail(("Failed to retrieve %s interface information."):format(interface)) + end + stdnse.print_debug("Will use %s interface.", interface.shortname) + else + local interface_list = nmap.list_interfaces() + local interface_good = {} + for _, os_interface in ipairs(interface_list) do + if os_interface.address and os_interface.link == "ethernet" and + os_interface.address:match("%d+%.%d+%.%d+%.%d+") then + + stdnse.print_debug(2, "Found usable interface: %s.", os_interface.shortname) + table.insert(interface_good, os_interface) + end + end + if #interface_good == 1 then + interface = interface_good[1] + stdnse.print_debug("Will use %s interface.", interface.shortname) + elseif #interface_good == 0 then + return fail("Source interface not found.") + else + return fail("Ambiguous source interface, please specify it with -e or interface parameter.") + end + end + + return ospfListen(interface, timeout) +end |