--- -- This module takes care of the authentication used in SMB (LM, NTLM, LMv2, NTLMv2). -- -- There is a lot to this functionality, so if you're interested in how it works, read -- on. -- In SMB authentication, there are two distinct concepts. Each will be dealt with -- separately. There are: -- * Stored hashes -- * Authentication -- -- What's confusing is that the same names are used for each of those. -- -- Stored Hashes: -- Windows stores two types of hashes: Lanman and NT Lanman (or NTLM). Vista and later -- store NTLM only. Lanman passwords are divided into two 7-character passwords and -- used as a key in DES, while NTLM is converted to unicode and MD4ed. -- -- The stored hashes can be dumped in a variety of ways (pwdump6, fgdump, Metasploit's -- priv module, smb-psexec.nse, etc). Generally, two hashes are dumped together -- (generally, Lanman:NTLM). Sometimes, Lanman is empty and only NTLM is given. Lanman -- is never required. -- -- The password hashes can be given instead of passwords when supplying credentials; -- this is done by using the smbhash argument. Either a pair of hashes -- can be passed, in the form of Lanman:NTLM, or a single hash, which is assumed to -- be NTLM. -- -- Authentication: -- There are four types of authentication. Confusingly, these have the same names as -- stored hashes, but only slight relationships. The four types are Lanmanv1, NTLMv1, -- Lanmanv2, and NTLMv2. By default, Lanmanv1 and NTLMv1 are used together in most -- applications. These Nmap scripts default to NTLMv1 alone, except in special cases, -- but it can be overridden by the user. -- -- Lanmanv1 and NTLMv1 both use DES for their response. The DES mixes a server challenge -- with the hash (Lanman hash for Lanmanv1 response and NTLMv1 hash for NTLM response). -- The way the challenge is DESed with the hashes is identical for Lanmanv1 and NTLMv1, -- the only difference is the starting hash (Lanman vs NTLM). -- -- Lanmanv2 and NTLMv2 both use HMAC-MD5 for their response. The HMAC-MD5 mixes a -- server challenge and a client challenge with the NTLM hash, in both cases. The -- difference between Lanmanv2 and NTLMv2 is the length of the client challenge; -- Lanmanv2 has a maximum client challenge of 8 bytes, whereas NTLMv2 doesn't limit -- the length of the client challenge. -- -- The primary advantage to the 'v2' protocols is the client challenge -- by -- incorporating a client challenge, a malicious server can't use a precomputation -- attack. -- -- In addition to hashing the passwords, messages are also signed, by default, if a -- v1 protocol is being used (I (Ron Bowes) couldn't get signatures to work on v2 -- protocols; if anybody knows how I'd love to implement it). -- --@args smbusername The SMB username to log in with. The forms "DOMAIN\username" and "username@DOMAIN" -- are not understood. To set a domain, use the smbdomain argument. --@args smbdomain The domain to log in with. If you aren't in a domained environment, then anything -- will (should?) be accepted by the server. --@args smbpassword The password to connect with. Be cautious with this, since some servers will lock -- accounts if the incorrect password is given. Although it's rare that the -- Administrator account can be locked out, in the off chance that it can, you could -- get yourself in trouble. To use a blank password, leave this parameter off -- altogether. --@args smbhash A password hash to use when logging in. This is given as a single hex string (32 -- characters) or a pair of hex strings (both 32 characters, optionally separated by a -- single character). These hashes are the LanMan or NTLM hash of the user's password, -- and are stored on disk or in memory. They can be retrieved from memory -- using the fgdump or pwdump tools. --@args smbtype The type of SMB authentication to use. These are the possible options: -- * v1: Sends LMv1 and NTLMv1. -- * LMv1: Sends LMv1 only. -- * NTLMv1: Sends NTLMv1 only (default). -- * v2: Sends LMv2 and NTLMv2. -- * LMv2: Sends LMv2 only. -- * NTLMv2: Doesn't exist; the protocol doesn't support NTLMv2 alone. -- The default, NTLMv1, is a pretty decent compromise between security and -- compatibility. If you are paranoid, you might want to use v2 or -- lmv2 for this. (Actually, if you're paranoid, you should be avoiding this -- protocol altogether!). If you're using an extremely old system, you might need to set -- this to v1 or lm, which are less secure but more compatible. -- For information, see smbauth.lua. --@args smbnoguest Use to disable usage of the 'guest' account. local bin = require "bin" local nmap = require "nmap" local stdnse = require "stdnse" local string = require "string" local table = require "table" _ENV = stdnse.module("smbauth", stdnse.seeall) local have_ssl, openssl = pcall(require, "openssl") -- Constants local NTLMSSP_NEGOTIATE = 0x00000001 local NTLMSSP_CHALLENGE = 0x00000002 local NTLMSSP_AUTH = 0x00000003 local session_key = string.rep(string.char(0x00), 16) -- Types of accounts (ordered by how useful they are local ACCOUNT_TYPES = { ANONYMOUS = 0, GUEST = 1, USER = 2, ADMIN = 3 } local function account_exists(host, username, domain) if(host.registry['smbaccounts'] == nil) then return false end for i, j in pairs(host.registry['smbaccounts']) do if(j['username'] == username and j['domain'] == domain) then return true end end return false end function next_account(host, num) if(num == nil) then if(host.registry['smbindex'] == nil) then host.registry['smbindex'] = 1 else host.registry['smbindex'] = host.registry['smbindex'] + 1 end else host.registry['smbindex'] = num end end ---Writes the given account to the registry. There are several places where accounts are stored: -- * registry['usernames'][username] => true -- * registry['smbaccounts'][username] => password -- * registry[ip]['smbaccounts'] => array of table containing 'username', 'password', and 'is_admin' -- -- The final place, 'smbaccount', is reserved for the "best" account. This is an administrator -- account, if one's found; otherwise, it's the first account discovered that isn't guest. -- -- This has to be called while no SMB connections are made, since it potentially makes its own connection. -- --@param host The host object. --@param username The username to add. --@param domain The domain to add. --@param password The password to add. --@param password_hash The password hash to add. --@param hash_type The hash type to use. --@param is_admin [optional] Set to 'true' the account is known to be an administrator. function add_account(host, username, domain, password, password_hash, hash_type, is_admin) -- Save the username in a global list -- TODO: restore this -- if(nmap.registry.usernames == nil) then -- nmap.registry.usernames = {} -- end -- nmap.registry.usernames[username] = true -- -- -- Save the username/password pair in a global list -- if(nmap.registry.smbaccounts == nil) then -- nmap.registry.smbaccounts = {} -- end -- nmap.registry.smbaccounts[username] = password -- Check if we've already recorded this account if(account_exists(host, username, domain)) then return end if(host.registry['smbaccounts'] == nil) then host.registry['smbaccounts'] = {} end -- Determine the type of account, if it wasn't given local account_type = nil if(is_admin) then account_type = ACCOUNT_TYPES.ADMIN else if(username == '') then -- Anonymous account account_type = ACCOUNT_TYPES.ANONYMOUS elseif(string.lower(username) == 'guest') then -- Guest account account_type = ACCOUNT_TYPES.GUEST else -- We have to assume it's a user-level account (we just can't call any SMB functions from inside here) account_type = ACCOUNT_TYPES.USER end end -- Set some defaults if(hash_type == nil) then hash_type = 'ntlm' end -- Save the new account if this is our first one, or our other account isn't an admin local new_entry = {} new_entry['username'] = username new_entry['domain'] = domain new_entry['password'] = password new_entry['password_hash'] = password_hash new_entry['hash_type'] = string.lower(hash_type) new_entry['account_type'] = account_type -- Insert the new entry into the table table.insert(host.registry['smbaccounts'], new_entry) -- Sort the table based on the account type (we want anonymous at the end, administrator at the front) table.sort(host.registry['smbaccounts'], function(a,b) return a['account_type'] > b['account_type'] end) -- Print a debug message stdnse.print_debug(1, "SMB: Added account '%s' to account list", username) -- Reset the credentials next_account(host, 1) -- io.write("\n\n" .. nsedebug.tostr(host.registry['smbaccounts']) .. "\n\n") end ---Retrieve the current set of credentials set in the registry. If these fail, next_credentials should be -- called. -- --@param host The host object. --@return (result, username, domain, password, password_hash, hash_type) If result is false, username is an error message. Otherwise, username and password are -- the current username and password that should be used. function get_account(host) if(host.registry['smbindex'] == nil) then host.registry['smbindex'] = 1 end local index = host.registry['smbindex'] local account = host.registry['smbaccounts'][index] if(account == nil) then return false, "No accounts left to try" end return true, account['username'], account['domain'], account['password'], account['password_hash'], account['hash_type'] end ---Create the account table with the anonymous and guest users, as well as the user given in the script's -- arguments, if there is one. -- --@param host The host object. function init_account(host) -- Don't run this more than once for each host if(host.registry['smbaccounts'] ~= nil) then return end -- Create the list host.registry['smbaccounts'] = {} -- Add the anonymous/guest accounts add_account(host, '', '', '', nil, 'none') if(not stdnse.get_script_args( "smbnoguest" )) then add_account(host, 'guest', '', '', nil, 'ntlm') end -- Add the account given on the commandline (TODO: allow more than one?) local args = nmap.registry.args local username = nil local domain = '' local password = nil local password_hash = nil local hash_type = 'ntlm' -- Do the username first if(args.smbusername ~= nil) then username = args.smbusername elseif(args.smbuser ~= nil) then username = args.smbuser end -- If the username exists, do everything else if(username ~= nil) then -- Domain if(args.smbdomain ~= nil) then domain = args.smbdomain end -- Type if(args.smbtype ~= nil) then hash_type = args.smbtype end -- Do the password if(args.smbpassword ~= nil) then password = args.smbpassword elseif(args.smbpass ~= nil) then password = args.smbpass end -- Only use the hash if there's no password if(password == nil) then password_hash = args.smbhash end -- Add the account, if we got a password if(password == nil and password_hash == nil) then stdnse.print_debug(1, "SMB: Either smbpass, smbpassword, or smbhash have to be passed as script arguments to use an account") else add_account(host, username, domain, password, password_hash, hash_type) end end end local function to_unicode(str) local unicode = "" for i = 1, #str, 1 do unicode = unicode .. bin.pack("Lanman function. -- --@param ntlm The NTLMv1 hash --@param challenge The server's challenge. --@return (status, response) If status is true, the response is returned; otherwise, an error message is returned. function ntlm_create_response(ntlm, challenge) if(have_ssl ~= true) then return false, "SMB: OpenSSL not present" end return lm_create_response(ntlm, challenge) end ---Create the NTLM mac key, which is used for message signing. For basic authentication, this is the md4 of the -- NTLM hash, concatenated with the response hash; for extended authentication, this is just the md4 of the NTLM -- hash. --@param ntlm_hash The NTLM hash. --@param ntlm_response The NTLM response. --@param is_extended Should be set if extended security negotiations are being used. function ntlm_create_mac_key(ntlm_hash, ntlm_response, is_extended) if(have_ssl ~= true) then return false, "SMB: OpenSSL not present" end if(is_extended) then return openssl.md4(ntlm_hash) else return openssl.md4(ntlm_hash) .. ntlm_response end end ---Create the LM mac key, which is used for message signing. For basic authentication, it's the first 8 bytes -- of the lanman hash, followed by 8 null bytes, followed by the lanman response; for extended authentication, -- this is just the first 8 bytes of the lanman hash followed by 8 null bytes. --@param lm_hash The NTLM hash. --@param lm_response The NTLM response. --@param is_extended Should be set if extended security negotiations are being used. function lm_create_mac_key(lm_hash, lm_response, is_extended) if(have_ssl ~= true) then return false, "SMB: OpenSSL not present" end if(is_extended) then return string.sub(lm_hash, 1, 8) .. string.rep(string.char(0), 8) else return string.sub(lm_hash, 1, 8) .. string.rep(string.char(0), 8) .. lm_response end end ---Create the NTLMv2 hash, which is based on the NTLMv1 hash (for easy upgrading), the username, and the domain. -- Essentially, the NTLM hash is used as a HMAC-MD5 key, which is used to hash the unicode domain concatenated -- with the unicode username. -- --@param ntlm The NTLMv1 hash. --@param username The username we're using. --@param domain The domain. --@return (status, response) If status is true, the response is returned; otherwise, an error message is returned. function ntlmv2_create_hash(ntlm, username, domain) if(have_ssl ~= true) then return false, "SMB: OpenSSL not present" end local unicode = "" username = to_unicode(string.upper(username)) domain = to_unicode(string.upper(domain)) return true, openssl.hmac("MD5", ntlm, username .. domain) end ---Create the LMv2 response, which can be sent back to the server. This is identical to the NTLMv2 function, -- except that it uses an 8-byte client challenge. -- -- The reason for LMv2 is a long and twisted story. Well, not really. The reason is basically that the v1 hashes -- are always 24-bytes, and some servers expect 24 bytes, but the NTLMv2 hash is more than 24 bytes. So, the only -- way to keep pass-through compatibility was to have a v2-hash that was guaranteed to be 24 bytes. So LMv1 was -- born -- it has a 16-byte hash followed by the 8-byte client challenge, for a total of 24 bytes. And now you've -- learned something -- --@param ntlm The NVLMv1 hash. --@param username The username we're using. --@param domain The domain. --@param challenge The server challenge. --@return (status, response) If status is true, the response is returned; otherwise, an error message is returned. function lmv2_create_response(ntlm, username, domain, challenge) if(have_ssl ~= true) then return false, "SMB: OpenSSL not present" end return ntlmv2_create_response(ntlm, username, domain, challenge, 8) end ---Create the NTLMv2 response, which can be sent back to the server. This is done by using the HMAC-MD5 algorithm -- with the NTLMv2 hash as a key, and the server challenge concatenated with the client challenge for the data. -- The resulting hash is concatenated with the client challenge and returned. -- -- The "proper" implementation for this uses a certain structure for the client challenge, involving the time -- and computer name and stuff (if you don't do this, Wireshark tells you it's a malformed packet). In my tests, -- however, I couldn't get Vista to recognize a client challenge longer than 24 bytes, and this structure was -- guaranteed to be much longer than 24 bytes. So, I just use a random string generated by OpenSSL. I've tested -- it on every Windows system from Windows 2000 to Windows Vista, and it has always worked. function ntlmv2_create_response(ntlm, username, domain, challenge, client_challenge_length) if(have_ssl ~= true) then return false, "SMB: OpenSSL not present" end local client_challenge = openssl.rand_bytes(client_challenge_length) local status, ntlmv2_hash = ntlmv2_create_hash(ntlm, username, domain) return true, openssl.hmac("MD5", ntlmv2_hash, challenge .. client_challenge) .. client_challenge end ---Generate the Lanman and NTLM password hashes. The password itself is taken from the function parameters, -- the nmap arguments, and the registry (in that order). If no password is set, then the password hash -- is used (which is read from all the usual places). If neither is set, then a blank password is used. -- -- The output passwords are hashed based on the hash type. -- --@param ip The ip address of the host, used for registry lookups. --@param username The username, which is used for v2 passwords. --@param domain The username, which is used for v2 passwords. --@param password [optional] The overriding password. --@param password_hash [optional] The overriding password hash. Shouldn't be set if password is set. --@param challenge The server challenge. --@param hash_type The way in which to hash the password. --@param is_extended Set to 'true' if extended security negotiations are being used (this has to be known for the -- message-signing key to be generated properly). --@return (lm_response, ntlm_response, mac_key) The two strings that can be sent directly back to the server, -- and the mac_key, which is used for message signing. function get_password_response(ip, username, domain, password, password_hash, hash_type, challenge, is_extended) local status local lm_hash = nil local ntlm_hash = nil local mac_key = nil local lm_response, ntlm_response -- Check for a blank password if(password == nil and password_hash == nil) then stdnse.print_debug(2, "SMB: Couldn't find password or hash to use (assuming blank)") password = "" end -- The anonymous user requires a single 0-byte instead of a LANMAN hash (don't ask me why, but it doesn't work without) if(hash_type == 'none') then return string.char(0), '', nil end -- If we got a password, hash it if(password ~= nil) then status, lm_hash = lm_create_hash(password) status, ntlm_hash = ntlm_create_hash(password) else if(password_hash ~= nil) then if(string.find(password_hash, "^" .. string.rep("%x%x", 16) .. "$")) then stdnse.print_debug(2, "SMB: Found a 16-byte hex string") lm_hash = bin.pack("H", password_hash:sub(1, 32)) ntlm_hash = bin.pack("H", password_hash:sub(1, 32)) elseif(string.find(password_hash, "^" .. string.rep("%x%x", 32) .. "$")) then stdnse.print_debug(2, "SMB: Found a 32-byte hex string") lm_hash = bin.pack("H", password_hash:sub(1, 32)) ntlm_hash = bin.pack("H", password_hash:sub(33, 64)) elseif(string.find(password_hash, "^" .. string.rep("%x%x", 16) .. "." .. string.rep("%x%x", 16) .. "$")) then stdnse.print_debug(2, "SMB: Found two 16-byte hex strings") lm_hash = bin.pack("H", password_hash:sub(1, 32)) ntlm_hash = bin.pack("H", password_hash:sub(34, 65)) else stdnse.print_debug(1, "SMB: ERROR: Hash(es) provided in an invalid format (should be 32, 64, or 65 hex characters)") lm_hash = nil ntlm_hash = nil end end end -- At this point, we should have a good lm_hash and ntlm_hash if we're getting one if(lm_hash == nil or ntlm_hash == nil) then stdnse.print_debug(2, "SMB: Couldn't determine which password to use, using a blank one") return "", "" end -- Output what we've got so far stdnse.print_debug(2, "SMB: Lanman hash: %s", stdnse.tohex(lm_hash)) stdnse.print_debug(2, "SMB: NTLM hash: %s", stdnse.tohex(ntlm_hash)) -- Hash the password the way the user wants if(hash_type == "v1") then -- LM and NTLM are hashed with their respective algorithms stdnse.print_debug(2, "SMB: Creating v1 response") status, lm_response = lm_create_response(lm_hash, challenge) status, ntlm_response = ntlm_create_response(ntlm_hash, challenge) mac_key = ntlm_create_mac_key(ntlm_hash, ntlm_response, is_extended) elseif(hash_type == "lm") then -- LM is hashed with its algorithm, NTLM is blank stdnse.print_debug(2, "SMB: Creating LMv1 response") status, lm_response = lm_create_response(lm_hash, challenge) ntlm_response = "" mac_key = lm_create_mac_key(lm_hash, lm_response, is_extended) elseif(hash_type == "ntlm") then -- LM and NTLM both use the NTLM algorithm stdnse.print_debug(2, "SMB: Creating NTLMv1 response") status, lm_response = ntlm_create_response(ntlm_hash, challenge) status, ntlm_response = ntlm_create_response(ntlm_hash, challenge) mac_key = ntlm_create_mac_key(ntlm_hash, ntlm_response, is_extended) elseif(hash_type == "v2") then -- LM and NTLM are hashed with their respective v2 algorithms stdnse.print_debug(2, "SMB: Creating v2 response") status, lm_response = lmv2_create_response(ntlm_hash, username, domain, challenge) status, ntlm_response = ntlmv2_create_response(ntlm_hash, username, domain, challenge, 24) elseif(hash_type == "lmv2") then -- LM is hashed with its v2 algorithm, NTLM is blank stdnse.print_debug(2, "SMB: Creating LMv2 response") status, lm_response = lmv2_create_response(ntlm_hash, username, domain, challenge) ntlm_response = "" else -- Default to NTLMv1 if(hash_type ~= nil) then stdnse.print_debug(1, "SMB: Invalid login type specified ('%s'), using default (NTLM)", hash_type) else stdnse.print_debug(1, "SMB: No login type specified, using default (NTLM)") end status, lm_response = ntlm_create_response(ntlm_hash, challenge) status, ntlm_response = ntlm_create_response(ntlm_hash, challenge) end stdnse.print_debug(2, "SMB: Lanman response: %s", stdnse.tohex(lm_response)) stdnse.print_debug(2, "SMB: NTLM response: %s", stdnse.tohex(ntlm_response)) return lm_response, ntlm_response, mac_key end function get_security_blob(security_blob, ip, username, domain, password, password_hash, hash_type, flags) local pos = 1 local new_blob local flags = flags or 0x00008215 -- (NEGOTIATE_SIGN_ALWAYS | NEGOTIATE_NTLM | NEGOTIATE_SIGN | REQUEST_TARGET | NEGOTIATE_UNICODE) if(security_blob == nil) then -- If security_blob is nil, this is the initial packet new_blob = bin.pack(" 0 ) and to_unicode(domain) or "" ntlm = (#username > 0 ) and ntlm or "" lanman = (#username > 0 ) and lanman or string.char(0) local domain_offset = 0x40 local username_offset = domain_offset + #domain local hostname_offset = username_offset + #username local lanman_offset = hostname_offset + #hostname local ntlm_offset = lanman_offset + #lanman local sessionkey_offset = ntlm_offset + #ntlm new_blob = bin.pack(" 0 and #ntlm - 16 or 0 ), ( #ntlm > 0 and #ntlm - 16 or 0 ), ntlm_offset, #domain, #domain, domain_offset, #username, #username, username_offset, #hostname, #hostname, hostname_offset, #session_key, #session_key, sessionkey_offset, flags, domain, username, hostname, lanman, ntlm, session_key) return true, new_blob, mac_key end end function get_host_info_from_security_blob(security_blob) local ntlm_challenge = {} --local pos, identifier, message_type, domain_length, domain_max, domain_offset, server_flags, challenge, reserved, target_info_length, target_info_max, target_info_offset = bin.unpack(" 0 ) then local length = domain_length local pos = domain_offset + 1 -- +1 to convert to Lua's 1-based indexes local target_realm pos, target_realm = bin.unpack( string.format( "A%d", length ), security_blob, pos ) ntlm_challenge[ "target_realm" ] = from_unicode( target_realm ) end -- Parse the TargetInfo data (Wireshark calls this the "Address List") if ( target_info_length > 0 ) then -- Definition of AvId values (IDs for AV_PAIR (attribute-value pair) structures), -- as definied by the NTLM Authentication Protocol specification [MS-NLMP]. local NTLM_AV_ID_VALUES = { MsvAvEOL = 0x0, MsvAvNbComputerName = 0x1, MsvAvNbDomainName = 0x2, MsvAvDnsComputerName = 0x3, MsvAvDnsDomainName = 0x4, MsvAvDnsTreeName = 0x5, MsvAvFlags = 0x6, MsvAvTimestamp = 0x7, MsvAvRestrictions = 0x8, MsvAvTargetName = 0x9, MsvAvChannelBindings = 0xA, } -- Friendlier names for AvId values, to be used as keys in the results table -- e.g. ntlm_challenge[ "dns_computer_name" ] -> "host.test.local" local NTLM_AV_ID_NAMES = { [NTLM_AV_ID_VALUES.MsvAvNbComputerName] = "netbios_computer_name", [NTLM_AV_ID_VALUES.MsvAvNbDomainName] = "netbios_domain_name", [NTLM_AV_ID_VALUES.MsvAvDnsComputerName] = "fqdn", [NTLM_AV_ID_VALUES.MsvAvDnsDomainName] = "dns_domain_name", [NTLM_AV_ID_VALUES.MsvAvDnsTreeName] = "dns_forest_name", [NTLM_AV_ID_VALUES.MsvAvTimestamp] = "timestamp", } local length = target_info_length local pos = target_info_offset + 1 -- +1 to convert to Lua's 1-based indexes local target_info pos, target_info = bin.unpack( string.format( "A%d", length ), security_blob, pos ) pos = 1 -- reset pos to 1, since we'll be working out of just the target_info repeat local value, av_id, av_len pos, av_id, av_len = bin.unpack( "= #target_info ) end return ntlm_challenge end ---Create an 8-byte message signature that's sent with all SMB packets. -- --@param mac_key The key used for authentication. It's the concatination of the session key and the -- response hash. --@param data The packet to generate the signature for. This should be the packet that's about to be -- sent, except with the signature slot replaced with the sequence number. --@return The 8-byte signature. The signature is equal to the first eight bytes of md5(mac_key .. smb_data) function calculate_signature(mac_key, data) if(have_ssl) then return string.sub(openssl.md5(mac_key .. data), 1, 8) else return string.rep(string.char(0), 8) end end return _ENV;