local http = require "http"
local nmap = require "nmap"
local shortport = require "shortport"
local stdnse = require "stdnse"
local string = require "string"

local openssl = stdnse.silent_require "openssl"

description = [[
Attempts to retrieve the PHP version from a web server. PHP has a number
of magic queries that return images or text that can vary with the PHP
version. This script uses the following queries:
* <code>/?=PHPE9568F36-D428-11d2-A769-00AA001ACF42</code>: gets a GIF logo, which changes on April Fool's Day.
* <code>/?=PHPB8B5F2A0-3C92-11d3-A3A9-4C7B08C10000</code>: gets an HTML credits page.

A list of magic queries is at http://www.0php.com/php_easter_egg.php.
The script also checks if any header field value starts with
<code>"PHP"</code> and reports that value if found.

PHP versions after 5.5.0 do not respond to these queries.

Link:
* http://phpsadness.com/sad/11
]]

---
-- @output
-- PORT   STATE SERVICE REASON
-- 80/tcp open  http    syn-ack
-- | http-php-version: Versions from logo query (less accurate): 4.3.11, 4.4.0 - 4.4.9, 5.0.4 - 5.0.5, 5.1.0 - 5.1.2
-- | Versions from credits query (more accurate): 5.0.5
-- |_Version from header x-powered-by: PHP/5.0.5

-- 2016-02-05: Updated versions based on scans of Internet hosts. Table is
--             likely complete, since new PHP versions are not vulnerable.
-- 08/10/2010:
--   * Added a check on the http status when querying the server:
--     if the http code is 200 (ok), proceed. (thanks to Tom Sellers who has reported this lack of check)

author = {"Ange Gutek", "Rob Nicholls"}
license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
categories = {"discovery", "safe"}


portrule = shortport.http

-- These are the magic queries that return fingerprintable data.
local LOGO_QUERY = "/?=PHPE9568F36-D428-11d2-A769-00AA001ACF42"
local CREDITS_QUERY = "/?=PHPB8B5F2A0-3C92-11d3-A3A9-4C7B08C10000"

-- For PHP 5.x hashes up to 5.2.14 and 5.3.3 see:
-- http://seclists.org/nmap-dev/2010/q4/518

local LOGO_HASHES = {
  -- Bunny (Carmella)
  ["37e194b799d4aaff10e39c4e3b2679a2"] = {"5.0.0 - 5.0.3"},
  -- Black Scottish Terrier (Scotch)
  ["4b2c92409cf0bcf465d199e93a15ac3f"] = {"4.3.11", "4.4.0 - 4.4.9", "5.0.4 - 5.0.5", "5.1.0 - 5.1.2"},
  -- Colored
  ["50caaf268b4f3d260d720a1a29c5fe21"] = {"5.1.3 - 5.1.6", "5.2.0 - 5.2.17"},
  -- PHP Code Guy With Breadsticks (Thies C. Arntzen)
  ["85be3b4be7bfe839cbb3b4f2d30ff983"] = {"4.0.0 - 4.2.3"},
  -- Brown Dog In Grass (Nadia)
  ["a57bd73e27be03a62dd6b3e1b537a72c"] = {"4.3.0 - 4.3.11"},
  -- Elephant
  ["fb3bbd9ccc4b3d9e0b3be89c5ff98a14"] = {"5.3.0 - 5.3.29", "5.4.0 - 5.4.45"},
}

local CREDITS_HASHES = {
  ["744aecef04f9ed1bc39ae773c40017d1"] = {"4.0.1pl2", "4.1.0 - 4.1.2", "4.2.2"},
  ["4ba58b973ecde12dafbbd40b54afac43"] = {"4.1.1 OpenVMS"},
  ["8bc001f58bf6c17a67e1ca288cb459cc"] = {"4.2.0 - 4.2.2"},
  ["3422eded2fcceb3c89cabb5156b5d4e2"] = {"4.2.3"},
  ["1e04761e912831dd29b7a98785e7ac61"] = {"4.3.0"},
  ["1e04761e912831dd29b7a98785e7ac61"] = {"4.3.1"},
  ["65eaaaa6c5fdc950e820f9addd514b8b"] = {"4.3.1 Mandrake Linux"},
  ["8a8b4a419103078d82707cf68226a482"] = {"4.3.2"},
  ["22d03c3c0a9cff6d760a4ba63909faea"] = {"4.3.2"}, -- entity encoded "'"
  ["8a4a61f60025b43f11a7c998f02b1902"] = {"4.3.3 - 4.3.5"},
  ["39eda6dfead77a33cc6c63b5eaeda244"] = {"4.3.3 - 4.3.5"}, -- entity encoded "'"
  ["913ec921cf487109084a518f91e70859"] = {"4.3.6 - 4.3.8"},
  ["884ba1f11e0e956c7c3ba64e5e33ee9f"] = {"4.3.6 - 4.3.8"}, -- entity encoded
  ["c5fa6aec2cf0172a5a1df7082335cf9e"] = {"4.3.8 Mandrake Linux"},
  ["8fbf48d5a2a64065fc26db3e890b9871"] = {"4.3.9 - 4.3.11"},
  ["f9b56b361fafd28b668cc3498425a23b"] = {"4.3.9 - 4.3.11"}, -- entity encoded "'"
  ["ddf16ec67e070ec6247ec1908c52377e"] = {"4.4.0"},
  ["3d7612c9927b4c5cfff43efd27b44124"] = {"4.4.0"}, -- entity encoded "'"
  ["55bc081f2d460b8e6eb326a953c0e71e"] = {"4.4.1"},
  ["bed7ceff09e9666d96fdf3518af78e0e"] = {"4.4.2 - 4.4.4"},
  ["692a87ca2c51523c17f597253653c777"] = {"4.4.5 - 4.4.7"},
  ["50ac182f03fc56a719a41fc1786d937d"] = {"4.4.8 - 4.4.9"},
  ["3c31e4674f42a49108b5300f8e73be26"] = {"5.0.0 - 5.0.5"},
  ["e54dbf41d985bfbfa316dba207ad6bce"] = {"5.0.0"},
  ["6be3565cdd38e717e4eb96868d9be141"] = {"5.0.5"},
  ["b7cf53972b35b5d57f12c9d857b6b507"] = {"5.0.5 ActiveScript"},
  ["5518a02af41478cfc492c930ace45ae5"] = {"5.1.0 - 5.1.1"},
  ["6cb0a5ba2d88f9d6c5c9e144dd5941a6"] = {"5.1.2"},
  ["82fa2d6aa15f971f7dadefe4f2ac20e3"] = {"5.1.3 - 5.1.6"},
  ["6a1c211f27330f1ab602c7c574f3a279"] = {"5.2.0"},
  ["d3894e19233d979db07d623f608b6ece"] = {"5.2.1"},
  ["56f9383587ebcc94558e11ec08584f05"] = {"5.2.2"},
  ["c37c96e8728dc959c55219d47f2d543f"] = {"5.2.3 - 5.2.5", "5.2.6RC3"},
  ["1776a7c1b3255b07c6b9f43b9f50f05e"] = {"5.2.6"},
  ["1ffc970c5eae684bebc0e0133c4e1f01"] = {"5.2.7 - 5.2.8"},
  ["54f426521bf61f2d95c8bfaa13857c51"] = {"5.2.9 - 5.2.14"},
  ["adb361b9255c1e5275e5bd6e2907c5fb"] = {"5.2.15 - 5.2.17"},
  ["db23b07a9b426d0d033565b878b1e384"] = {"5.3.0"},
  ["a4c057b11fa0fba98c8e26cd7bb762a8"] = {"5.3.1 - 5.3.2"},
  ["b34501471d51cebafacdd45bf2cd545d"] = {"5.3.3"},
  ["e3b18899d0ffdf8322ed18d7bce3c9a0"] = {"5.3.4 - 5.3.5"},
  ["2e7f5372931a7f6f86786e95871ac947"] = {"5.3.6"},
  ["f1f1f60ac0dcd700a1ad30aa81175d34"] = {"5.3.7 - 5.3.8"},
  ["23f183b78eb4e3ba8b3df13f0a15e5de"] = {"5.3.9 - 5.3.29"},
  ["85da0a620fabe694dab1d55cbf1e24c3"] = {"5.4.0 - 5.4.14"},
  ["ebf6d0333d67af5f80077438c45c8eaa"] = {"5.4.15 - 5.4.45"},
}

action = function(host, port)
  local response
  local logo_versions, credits_versions
  local logo_hash, credits_hash
  local header_name, header_value
  local lines

  -- 1st pass : the "special" PHP-logo test
  response = http.get(host, port, LOGO_QUERY)
  if response.body and response.status == 200 then
    logo_hash = stdnse.tohex(openssl.md5(response.body))
    logo_versions = LOGO_HASHES[logo_hash]
  end

  -- 2nd pass : the PHP-credits test
  response = http.get(host, port, CREDITS_QUERY)
  if response.body and response.status == 200 then
    credits_hash = stdnse.tohex(openssl.md5(response.body))
    credits_versions = CREDITS_HASHES[credits_hash]
  end

  for name, value in pairs(response.header) do
    if string.match(value, "^PHP/") then
      header_name = name
      header_value = value
      break
    end
  end

  lines = {}
  if logo_versions then
    lines[#lines + 1] = "Versions from logo query (less accurate): " .. stdnse.strjoin(", ", logo_versions)
  elseif logo_hash and nmap.verbosity() >= 2 then
    lines[#lines + 1] = "Logo query returned unknown hash " .. logo_hash
  end
  if credits_versions then
    lines[#lines + 1] = "Versions from credits query (more accurate): " .. stdnse.strjoin(", ", credits_versions)
  elseif credits_hash and nmap.verbosity() >= 2 then
    lines[#lines + 1] = "Credits query returned unknown hash " .. credits_hash
  end
  if header_name and header_value then
    lines[#lines + 1] = "Version from header " .. header_name .. ": " .. header_value
  end

  if #lines > 0 then
    return stdnse.strjoin("\n", lines)
  end
end