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Diffstat (limited to 'scripts/rdp-enum-encryption.nse')
| -rw-r--r-- | scripts/rdp-enum-encryption.nse | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/scripts/rdp-enum-encryption.nse b/scripts/rdp-enum-encryption.nse new file mode 100644 index 0000000..6451bee --- /dev/null +++ b/scripts/rdp-enum-encryption.nse @@ -0,0 +1,213 @@ +description = [[ +Determines which Security layer and Encryption level is supported by the +RDP service. It does so by cycling through all existing protocols and ciphers. +When run in debug mode, the script also returns the protocols and ciphers that +fail and any errors that were reported. + +The script was inspired by MWR's RDP Cipher Checker +http://labs.mwrinfosecurity.com/tools/2009/01/12/rdp-cipher-checker/ +]] + +--- +-- @usage +-- nmap -p 3389 --script rdp-enum-encryption <ip> +-- +-- @output +-- PORT STATE SERVICE +-- 3389/tcp open ms-wbt-server +-- | Security layer +-- | CredSSP (NLA): SUCCESS +-- | CredSSP with Early User Auth: SUCCESS +-- | Native RDP: SUCCESS +-- | RDSTLS: SUCCESS +-- | SSL: SUCCESS +-- | RDP Encryption level: High +-- | 40-bit RC4: SUCCESS +-- | 56-bit RC4: SUCCESS +-- | 128-bit RC4: SUCCESS +-- | FIPS 140-1: SUCCESS +-- |_ RDP Protocol Version: RDP 5.x, 6.x, 7.x, or 8.x server +-- + +author = "Patrik Karlsson" +license = "Same as Nmap--See https://nmap.org/book/man-legal.html" + + +local nmap = require("nmap") +local table = require("table") +local shortport = require("shortport") +local rdp = require("rdp") +local stdnse = require("stdnse") +local string = require "string" + +categories = {"safe", "discovery"} + +portrule = shortport.port_or_service(3389, "ms-wbt-server") + +local function fail (err) return stdnse.format_output(false, err) end + +local function enum_protocols(host, port) + local PROTOCOLS = { + ["Native RDP"] = 0, + ["SSL"] = 1, + ["CredSSP (NLA)"] = 3, + ["RDSTLS"] = 4, + ["CredSSP with Early User Auth"] = 8 + } + + local ERRORS = { + [1] = "SSL_REQUIRED_BY_SERVER", + [2] = "SSL_NOT_ALLOWED_BY_SERVER", + [3] = "SSL_CERT_NOT_ON_SERVER", + [4] = "INCONSISTENT_FLAGS", + [5] = "HYBRID_REQUIRED_BY_SERVER" + } + + local res_proto = { name = "Security layer" } + local proto_version + + for k, v in pairs(PROTOCOLS) do + -- Prevent reconnecting too quickly, improves reliability + stdnse.sleep(0.2) + + local comm = rdp.Comm:new(host, port) + if ( not(comm:connect()) ) then + return false, fail("Failed to connect to server") + end + local cr = rdp.Request.ConnectionRequest:new(v) + local status, response = comm:exch(cr) + + if status then + if response.itut.data ~= "" then + local success = string.unpack("B", response.itut.data) + + if ( success == 2 ) then + table.insert(res_proto, ("%s: SUCCESS"):format(k)) + elseif ( nmap.debugging() > 0 ) then + local err = string.unpack("B", response.itut.data, 5) + if ( err > 0 ) then + table.insert(res_proto, ("%s: FAILED (%s)"):format(k, ERRORS[err] or "Unknown")) + else + table.insert(res_proto, ("%s: FAILED"):format(k)) + end + end + else + -- rdpNegData, which contains the negotiation response or failure, + -- is optional. WinXP SP3 does not return this section which means + -- we can't tell if the protocol is accepted or not. + table.insert(res_proto, ("%s: Unknown"):format(k)) + end + else + comm:close() + return false, response + end + + -- For servers that require TLS or NLA the only way to get the RDP protocol + -- version to negotiate TLS or NLA. This section does that for TLS. There + -- is no NLA currently. + if status and (v == 1) then + local res, _ = comm.socket:reconnect_ssl() + if res then + local msc = rdp.Request.MCSConnectInitial:new(0, 1) + status, response = comm:exch(msc) + if status then + if response.ccr.proto_version then + proto_version = response.ccr.proto_version + end + end + end + end + + comm:close() + end + table.sort(res_proto) + return true, res_proto, proto_version +end + +local function enum_ciphers(host, port) + + local CIPHERS = { + { ["40-bit RC4"] = 1 }, + { ["56-bit RC4"] = 8 }, + { ["128-bit RC4"] = 2 }, + { ["FIPS 140-1"] = 16 } + } + + local ENC_LEVELS = { + [0] = "None", + [1] = "Low", + [2] = "Client Compatible", + [3] = "High", + [4] = "FIPS Compliant", + } + + local res_ciphers = {} + local proto_version + + local function get_ordered_ciphers() + local i = 0 + return function() + i = i + 1 + if ( not(CIPHERS[i]) ) then return end + for k,v in pairs(CIPHERS[i]) do + return k, v + end + end + end + + for k, v in get_ordered_ciphers() do + -- Prevent reconnecting too quickly, improves reliability + stdnse.sleep(0.2) + + local comm = rdp.Comm:new(host, port) + if ( not(comm:connect()) ) then + return false, fail("Failed to connect to server") + end + + local cr = rdp.Request.ConnectionRequest:new() + local status, _ = comm:exch(cr) + if ( not(status) ) then + break + end + + local msc = rdp.Request.MCSConnectInitial:new(v) + local status, response = comm:exch(msc) + comm:close() + if ( status ) then + if ( response.ccr and response.ccr.enc_cipher == v ) then + table.insert(res_ciphers, ("%s: SUCCESS"):format(k)) + end + res_ciphers.name = ("RDP Encryption level: %s"):format(ENC_LEVELS[response.ccr.enc_level] or "Unknown") + + if response.ccr.proto_version then + proto_version = response.ccr.proto_version + end + elseif ( nmap.debugging() > 0 ) then + table.insert(res_ciphers, ("%s: FAILURE"):format(k)) + end + end + return true, res_ciphers, proto_version +end + +action = function(host, port) + local result = {} + + local status, res_proto, proto_ver = enum_protocols(host, port) + if ( not(status) ) then + return res_proto + end + + local status, res_ciphers, cipher_ver = enum_ciphers(host, port) + if ( not(status) ) then + return res_ciphers + end + + table.insert(result, res_proto) + table.insert(result, res_ciphers) + if proto_ver then + table.insert(result, proto_ver) + elseif cipher_ver then + table.insert(result, cipher_ver) + end + return stdnse.format_output(true, result) +end |