local stdnse = require "stdnse" local openssl = stdnse.silent_require "openssl" local nmap = require "nmap" local shortport = require "shortport" local ssh2 = require "ssh2" local sslcert = require "sslcert" local math = require "math" local string = require "string" local vulns = require "vulns" description = [[ Detects RSA keys vulnerable to Return Of Coppersmith Attack (ROCA) factorization. SSH hostkeys and SSL/TLS certificates are checked. The checks require recent updates to the openssl NSE library. References: * https://crocs.fi.muni.cz/public/papers/rsa_ccs17 ]] --- -- @usage -- nmap -p 22,443 --script rsa-vuln-roca -- -- @output -- --@xmloutput -- -- @see ssl-cert.nse -- @see ssh-hostkey.nse author = "Daniel Miller" license = "Same as Nmap--See https://nmap.org/book/man-legal.html" categories = {"vuln", "safe"} -- only run this script if the target host is NOT a private (RFC1918) IP address) -- and the port is an open SSL service portrule = function(host, port) if not openssl.bignum_div then stdnse.verbose1("This script requires the latest update to NSE's openssl library bindings.") return false end -- SSH key check return shortport.port_or_service(22, "ssh") -- same criteria as ssl-cert.nse or shortport.ssl(host, port) or sslcert.isPortSupported(port) or sslcert.getPrepareTLSWithoutReconnect(port) end local function is_vulnerable (modulus) local dec2bn = openssl.bignum_dec2bn -- Prime tests used under MIT license from https://github.com/crocs-muni/roca local prime_tests = nmap.registry.roca_prime_tests or { {dec2bn("3"), dec2bn("6")}, {dec2bn("5"), dec2bn("30")}, {dec2bn("7"), dec2bn("126")}, {dec2bn("11"), dec2bn("1026")}, {dec2bn("13"), dec2bn("5658")}, {dec2bn("17"), dec2bn("107286")}, {dec2bn("19"), dec2bn("199410")}, {dec2bn("23"), dec2bn("8388606")}, {dec2bn("29"), dec2bn("536870910")}, {dec2bn("31"), dec2bn("2147483646")}, {dec2bn("37"), dec2bn("67109890")}, {dec2bn("41"), dec2bn("2199023255550")}, {dec2bn("43"), dec2bn("8796093022206")}, {dec2bn("47"), dec2bn("140737488355326")}, {dec2bn("53"), dec2bn("5310023542746834")}, {dec2bn("59"), dec2bn("576460752303423486")}, {dec2bn("61"), dec2bn("1455791217086302986")}, {dec2bn("67"), dec2bn("147573952589676412926")}, {dec2bn("71"), dec2bn("20052041432995567486")}, {dec2bn("73"), dec2bn("6041388139249378920330")}, {dec2bn("79"), dec2bn("207530445072488465666")}, {dec2bn("83"), dec2bn("9671406556917033397649406")}, {dec2bn("89"), dec2bn("618970019642690137449562110")}, {dec2bn("97"), dec2bn("79228162521181866724264247298")}, {dec2bn("101"), dec2bn("2535301200456458802993406410750")}, {dec2bn("103"), dec2bn("1760368345969468176824550810518")}, {dec2bn("107"), dec2bn("50079290986288516948354744811034")}, {dec2bn("109"), dec2bn("473022961816146413042658758988474")}, {dec2bn("113"), dec2bn("10384593717069655257060992658440190")}, {dec2bn("127"), dec2bn("144390480366845522447407333004847678774")}, {dec2bn("131"), dec2bn("2722258935367507707706996859454145691646")}, {dec2bn("137"), dec2bn("174224571863520493293247799005065324265470")}, {dec2bn("139"), dec2bn("696898287454081973172991196020261297061886")}, {dec2bn("149"), dec2bn("713623846352979940529142984724747568191373310")}, {dec2bn("151"), dec2bn("1800793591454480341970779146165214289059119882")}, {dec2bn("157"), dec2bn("126304807362733370595828809000324029340048915994")}, {dec2bn("163"), dec2bn("11692013098647223345629478661730264157247460343806")}, {dec2bn("167"), dec2bn("187072209578355573530071658587684226515959365500926")}, } nmap.registry.roca_prime_tests = prime_tests --stdnse.debug1("Testing %s", openssl.bignum_bn2dec(modulus)) for _, test in ipairs(prime_tests) do local prime, fingerprint = test[1], test[2] local _, bnshift = openssl.bignum_div(modulus, prime) -- prime is small, so bnshift is small. Safe to convert to Lua integer local string_shift = openssl.bignum_bn2dec(bnshift) local shift = math.tointeger(string_shift) if not shift then stdnse.debug1("Unable to convert %s to integer", string_shift) return nil end --stdnse.debug1("Testing mod %s, shift is %s", openssl.bignum_bn2dec(prime), shift) if not openssl.bignum_is_bit_set(fingerprint, shift) then stdnse.debug1("Not vulnerable") return nil end end stdnse.debug1("VULNERABLE!!!!!!") return "Vulnerable to ROCA" end local function ssl_get_modulus(host, port) local ok, cert = sslcert.getCertificate(host, port) if not ok then stdnse.debug1("failed to obtain SSL certificate") return nil end if cert.pubkey.type ~= "rsa" then stdnse.debug1("Non-RSA certificate, not vulnerable to ROCA") return nil end local modulus = cert.pubkey.modulus if not modulus then stdnse.debug1("No modulus available; upgrade Nmap?") return nil end return modulus end local function ssh_get_modulus(host, port) local key = ssh2.fetch_host_key( host, port, "ssh-rsa" ) if not key then stdnse.debug1("No RSA hostkey, not vulnerable to ROCA") return nil end local _, e, n = string.unpack(">s4s4s4", key.fp_input) return openssl.bignum_bin2bn(n) end action = function(host, port) local vuln_table = { title = "ROCA: Vulnerable RSA generation", state = vulns.STATE.NOT_VULN, -- TODO: Update when CVE is scored --risk_factor = "High", description = [[ The Infineon RSA library 1.02.013 in Infineon Trusted Platform Module (TPM) firmware, such as versions before 0000000000000422 - 4.34, before 000000000000062b - 6.43, and before 0000000000008521 - 133.33, mishandles RSA key generation, which makes it easier for attackers to defeat various cryptographic protection mechanisms via targeted attacks, aka ROCA. ]], IDS = {CVE = "CVE-2017-15361"}, references = { "https://crocs.fi.muni.cz/public/papers/rsa_ccs17", } } local report = vulns.Report:new(SCRIPT_NAME, host, port) local modulus if shortport.ssl(host, port) or sslcert.isPortSupported(port) or sslcert.getPrepareTLSWithoutReconnect(port) then modulus = ssl_get_modulus(host, port) elseif shortport.port_or_service(22, "ssh")(host, port) then modulus = ssh_get_modulus(host, port) end if modulus and is_vulnerable(modulus) then vuln_table.state = vulns.STATE.VULN end return report:make_output(vuln_table) end