---Implements the HTTP client protocol in a standard form that Nmap scripts can -- take advantage of. -- -- Because HTTP has so many uses, there are a number of interfaces to this library. -- The most obvious and common ones are simply get, post, -- and head; or, if more control is required, generic_request -- can be used. These functions do what one would expect. The get_url -- helper function can be used to parse and retrieve a full URL. -- -- These functions return a table of values, including: -- * status-line - A string representing the status, such as "HTTP/1.1 200 OK". In case of an error, a description will be provided in this line. -- * status: The HTTP status value; for example, "200". If an error occurs during a request, then this value is going to be nil. -- * header - An associative array representing the header. Keys are all lowercase, and standard headers, such as 'date', 'content-length', etc. will typically be present. -- * rawheader - A numbered array of the headers, exactly as the server sent them. While header['content-type'] might be 'text/html', rawheader[3] might be 'Content-type: text/html'. -- * cookies - A numbered array of the cookies the server sent. Each cookie is a table with the following keys: name, value, path, domain, and expires. -- * body - The full body, as returned by the server. -- -- If a script is planning on making a lot of requests, the pipelining functions can -- be helpful. pipeline_add queues requests in a table, and -- pipeline performs the requests, returning the results as an array, -- with the responses in the same order as the queries were added. As a simple example: --


--	-- Start by defining the 'all' variable as nil
--	local all = nil
--
--	-- Add two 'GET' requests and one 'HEAD' to the queue. These requests are not performed
--	-- yet. The second parameter represents the 'options' table, which we don't need.
--	all = http.pipeline_add('/book',          nil, all)
--	all = http.pipeline_add('/test',          nil, all)
--	all = http.pipeline_add('/monkeys',       nil, all)
--
--	-- Perform all three requests as parallel as Nmap is able to
--	local results = http.pipeline('nmap.org', 80, all)
--

-- -- At this point, results is an array with three elements. Each element -- is a table containing the HTTP result, as discussed above. -- -- One more interface provided by the HTTP library helps scripts determine whether or not -- a page exists. The identify_404 function will try several URLs on the -- server to determine what the server's 404 pages look like. It will attempt to identify -- customized 404 pages that may not return the actual status code 404. If successful, -- the function page_exists can then be used to determine whether or not -- a page existed. -- -- Some other miscellaneous functions that can come in handy are response_contains, -- can_use_head, and save_path. See the appropriate documentation -- for them. -- -- The response to each function is typically a table with the following keys: -- status-line: The HTTP status line; for example, "HTTP/1.1 200 OK" (note: this is followed by a newline). In case of an error, a description will be provided in this line. -- status: The HTTP status value; for example, "200". If an error occurs during a request, then this value is going to be nil. -- header: A table of header values, where the keys are lowercase and the values are exactly what the server sent -- rawheader: A list of header values as "name: value" strings, in the exact format and order that the server sent them -- cookies: A list of cookies that the server is sending. Each cookie is a table containing the keys name, value, and path. This table can be sent to the server in subsequent responses in the options table to any function (see below). -- body: The body of the response -- -- Many of the functions optionally allow an 'options' table. This table can alter the HTTP headers -- or other values like the timeout. The following are valid values in 'options' (note: not all -- options will necessarily affect every function): -- * timeout: A timeout used for socket operations. -- * header: A table containing additional headers to be used for the request. For example, options['header']['Content-Type'] = 'text/xml' -- * content: The content of the message (content-length will be added -- set header['Content-Length'] to override). This can be either a string, which will be directly added as the body of the message, or a table, which will have each key=value pair added (like a normal POST request). -- * cookies: A list of cookies as either a string, which will be directly sent, or a table. If it's a table, the following fields are recognized: -- ** name -- ** value -- ** path -- * auth: A table containing the keys username and password, which will be used for HTTP Basic authentication. -- If a server requires HTTP Digest authentication, then there must also be a key digest, with value true. -- * bypass_cache: Do not perform a lookup in the local HTTP cache. -- * no_cache: Do not save the result of this request to the local HTTP cache. -- * no_cache_body: Do not save the body of the response to the local HTTP cache. -- * redirect_ok: Closure that overrides the default redirect_ok used to validate whether to follow HTTP redirects or not. False, if no HTTP redirects should be followed. -- The following example shows how to write a custom closure that follows 5 consecutive redirects: --


--   redirect_ok = function(host,port)
--     local c = 5
--     return function(url)
--       if ( c==0 ) then return false end
--       c = c - 1
--       return true
--     end
--   end
--

-- -- @args http.max-cache-size The maximum memory size (in bytes) of the cache. -- -- @args http.useragent The value of the User-Agent header field sent with -- requests. By default it is -- "Mozilla/5.0 (compatible; Nmap Scripting Engine; http://nmap.org/book/nse.html)". -- A value of the empty string disables sending the User-Agent header field. -- -- @args http.pipeline If set, it represents the number of HTTP requests that'll be -- sent on one connection. This can be set low to make debugging easier, or it -- can be set high to test how a server reacts (its chosen max is ignored). -- @args http.max-pipeline If set, it represents the number of outstanding HTTP requests -- that should be pipelined. Defaults to http.pipeline (if set), or to what -- getPipelineMax function returns. -- -- TODO -- Implement cache system for http pipelines -- local base64 = require "base64" local comm = require "comm" local coroutine = require "coroutine" local nmap = require "nmap" local os = require "os" local sasl = require "sasl" local stdnse = require "stdnse" local string = require "string" local table = require "table" local url = require "url" _ENV = stdnse.module("http", stdnse.seeall) ---Use ssl if we have it local have_ssl, openssl = pcall(require,'openssl') USER_AGENT = stdnse.get_script_args('http.useragent') or "Mozilla/5.0 (compatible; Nmap Scripting Engine; http://nmap.org/book/nse.html)" local MAX_REDIRECT_COUNT = 5 -- Recursively copy a table. -- Only recurs when a value is a table, other values are copied by assignment. local function tcopy (t) local tc = {}; for k,v in pairs(t) do if type(v) == "table" then tc[k] = tcopy(v); else tc[k] = v; end end return tc; end --- Recursively copy into a table any elements from another table whose key it -- doesn't have. local function table_augment(to, from) for k, v in pairs(from) do if type( to[k] ) == 'table' then table_augment(to[k], from[k]) else to[k] = from[k] end end end --- Get a value suitable for the Host header field. local function get_host_field(host, port) local hostname = stdnse.get_hostname(host) local portno if port == nil then portno = 80 elseif type(port) == "table" then portno = port.number else portno = port end if portno == 80 then return hostname else return hostname .. ":" .. tostring(portno) end end -- Skip *( SP | HT ) starting at offset. See RFC 2616, section 2.2. -- @return the first index following the spaces. -- @return the spaces skipped over. local function skip_space(s, offset) local _, i, space = s:find("^([ \t]*)", offset) return i + 1, space end -- Get a token starting at offset. See RFC 2616, section 2.2. -- @return the first index following the token, or nil if no token was found. -- @return the token. local function get_token(s, offset) -- All characters except CTL and separators. local _, i, token = s:find("^([^()<>@,;:\\\"/%[%]?={} \0\001-\031\127]+)", offset) if i then return i + 1, token else return nil end end -- Get a quoted-string starting at offset. See RFC 2616, section 2.2. crlf is -- used as the definition for CRLF in the case of LWS within the string. -- @return the first index following the quoted-string, or nil if no -- quoted-string was found. -- @return the contents of the quoted-string, without quotes or backslash -- escapes. local function get_quoted_string(s, offset, crlf) local result = {} local i = offset assert(s:sub(i, i) == "\"") i = i + 1 while i <= s:len() do local c = s:sub(i, i) if c == "\"" then -- Found the closing quote, done. return i + 1, table.concat(result) elseif c == "\\" then -- This is a quoted-pair ("\" CHAR). i = i + 1 c = s:sub(i, i) if c == "" then -- No character following. error(string.format("\\ escape at end of input while parsing quoted-string.")) end -- Only CHAR may follow a backslash. if c:byte(1) > 127 then error(string.format("Unexpected character with value > 127 (0x%02X) in quoted-string.", c:byte(1))) end else -- This is qdtext, which is TEXT except for '"'. -- TEXT is "any OCTET except CTLs, but including LWS," however "a CRLF is -- allowed in the definition of TEXT only as part of a header field -- continuation." So there are really two definitions of quoted-string, -- depending on whether it's in a header field or not. This function does -- not allow CRLF. c = s:sub(i, i) if c ~= "\t" and c:match("^[\0\001-\031\127]$") then error(string.format("Unexpected control character in quoted-string: 0x%02X.", c:byte(1))) end end result[#result + 1] = c i = i + 1 end return nil end -- Get a ( token | quoted-string ) starting at offset. -- @return the first index following the token or quoted-string, or nil if -- nothing was found. -- @return the token or quoted-string. local function get_token_or_quoted_string(s, offset, crlf) if s:sub(offset, offset) == "\"" then return get_quoted_string(s, offset) else return get_token(s, offset) end end -- Returns the index just past the end of LWS. local function skip_lws(s, pos) local _, e while true do while string.match(s, "^[ \t]", pos) do pos = pos + 1 end _, e = string.find(s, "^\r?\n[ \t]", pos) if not e then return pos end pos = e + 1 end end ---Validate an 'options' table, which is passed to a number of the HTTP functions. It is -- often difficult to track down a mistake in the options table, and requires fiddling -- with the http.lua source, but this should make that a lot easier. local function validate_options(options) local bad = false if(options == nil) then return true end for key, value in pairs(options) do if(key == 'timeout') then if(type(tonumber(value)) ~= 'number') then stdnse.print_debug(1, 'http: options.timeout contains a non-numeric value') bad = true end elseif(key == 'header') then if(type(value) ~= 'table') then stdnse.print_debug(1, "http: options.header should be a table") bad = true end elseif(key == 'content') then if(type(value) ~= 'string' and type(value) ~= 'table') then stdnse.print_debug(1, "http: options.content should be a string or a table") bad = true end elseif(key == 'cookies') then if(type(value) == 'table') then for _, cookie in ipairs(value) do for cookie_key, cookie_value in pairs(cookie) do if(cookie_key == 'name') then if(type(cookie_value) ~= 'string') then stdnse.print_debug(1, "http: options.cookies[i].name should be a string") bad = true end elseif(cookie_key == 'value') then if(type(cookie_value) ~= 'string') then stdnse.print_debug(1, "http: options.cookies[i].value should be a string") bad = true end elseif(cookie_key == 'path') then if(type(cookie_value) ~= 'string') then stdnse.print_debug(1, "http: options.cookies[i].path should be a string") bad = true end elseif(cookie_key == 'expires') then if(type(cookie_value) ~= 'string') then stdnse.print_debug(1, "http: options.cookies[i].expires should be a string") bad = true end else stdnse.print_debug(1, "http: Unknown field in cookie table: %s", cookie_key) bad = true end end end elseif(type(value) ~= 'string') then stdnse.print_debug(1, "http: options.cookies should be a table or a string") bad = true end elseif(key == 'auth') then if(type(value) == 'table') then if(value['username'] == nil or value['password'] == nil) then stdnse.print_debug(1, "http: options.auth should contain both a 'username' and a 'password' key") bad = true end else stdnse.print_debug(1, "http: options.auth should be a table") bad = true end elseif (key == 'digestauth') then if(type(value) == 'table') then local req_keys = {"username","realm","nonce","digest-uri","response"} for _,k in ipairs(req_keys) do if not value[k] then stdnse.print_debug(1, "http: options.digestauth missing key: %s",k) bad = true break end end else bad = true stdnse.print_debug(1, "http: options.digestauth should be a table") end elseif(key == 'bypass_cache' or key == 'no_cache' or key == 'no_cache_body') then if(type(value) ~= 'boolean') then stdnse.print_debug(1, "http: options.bypass_cache, options.no_cache, and options.no_cache_body must be boolean values") bad = true end elseif(key == 'redirect_ok') then if(type(value)~= 'function' and type(value)~='boolean') then stdnse.print_debug(1, "http: options.redirect_ok must be a function or boolean") bad = true end else stdnse.print_debug(1, "http: Unknown key in the options table: %s", key) end end return not(bad) end -- The following recv functions, and the function next_response -- follow a common pattern. They each take a partial argument -- whose value is data that has been read from the socket but not yet used in -- parsing, and they return as their second return value a new value for -- partial. The idea is that, for example, in reading from the -- socket to get the Status-Line, you will probably read too much and read part -- of the header. That part (the "partial") has to be retained when you go to -- parse the header. The common use pattern is this: --


-- local partial
-- status_line, partial = recv_line(socket, partial)
-- ...
-- header, partial = recv_header(socket, partial)
-- ...
--

-- On error, the functions return nil and the second return value -- is an error message. -- Receive a single line (up to \n). local function recv_line(s, partial) local _, e local status, data local pos partial = partial or "" pos = 1 while true do _, e = string.find(partial, "\n", pos, true) if e then break end status, data = s:receive() if not status then return status, data end pos = #partial partial = partial .. data end return string.sub(partial, 1, e), string.sub(partial, e + 1) end local function line_is_empty(line) return line == "\r\n" or line == "\n" end -- Receive up to and including the first blank line, but return everything up -- to and not including the final blank line. local function recv_header(s, partial) local lines = {} partial = partial or "" while true do local line line, partial = recv_line(s, partial) if not line then return line, partial end if line_is_empty(line) then break end lines[#lines + 1] = line end return table.concat(lines), partial end -- Receive until the connection is closed. local function recv_all(s, partial) local parts partial = partial or "" parts = {partial} while true do local status, part = s:receive() if not status then break else parts[#parts + 1] = part end end return table.concat(parts), "" end -- Receive exactly length bytes. Returns nil if that -- many aren't available. local function recv_length(s, length, partial) local parts, last partial = partial or "" parts = {} last = partial length = length - #last while length > 0 do local status parts[#parts + 1] = last status, last = s:receive() if not status then return nil end length = length - #last end -- At this point length is 0 or negative, and indicates the degree to which -- the last read "overshot" the desired length. if length == 0 then return table.concat(parts) .. last, "" else return table.concat(parts) .. string.sub(last, 1, length - 1), string.sub(last, length) end end -- Receive until the end of a chunked message body, and return the dechunked -- body. local function recv_chunked(s, partial) local chunks, chunk local chunk_size local pos chunks = {} repeat local line, hex, _, i line, partial = recv_line(s, partial) if not line then return nil, partial end pos = 1 pos = skip_space(line, pos) -- Get the chunk-size. _, i, hex = string.find(line, "^([%x]+)", pos) if not i then return nil, string.format("Chunked encoding didn't find hex; got %q.", string.sub(line, pos, pos + 10)) end pos = i + 1 chunk_size = tonumber(hex, 16) if not chunk_size or chunk_size < 0 then return nil, string.format("Chunk size %s is not a positive integer.", hex) end -- Ignore chunk-extensions that may follow here. -- RFC 2616, section 2.1 ("Implied *LWS") seems to allow *LWS between the -- parts of a chunk-extension, but that is ambiguous. Consider this case: -- "1234;a\r\n =1\r\n...". It could be an extension with a chunk-ext-name -- of "a" (and no value), and a chunk-data beginning with " =", or it could -- be a chunk-ext-name of "a" with a value of "1", and a chunk-data -- starting with "...". We don't allow *LWS here, only ( SP | HT ), so the -- first interpretation will prevail. chunk, partial = recv_length(s, chunk_size, partial) if not chunk then return nil, partial end chunks[#chunks + 1] = chunk line, partial = recv_line(s, partial) if not line then -- this warning message was initially an error but was adapted -- to support broken servers, such as the Citrix XML Service stdnse.print_debug(2, "Didn't find CRLF after chunk-data.") elseif not string.match(line, "^\r?\n") then return nil, string.format("Didn't find CRLF after chunk-data; got %q.", line) end until chunk_size == 0 return table.concat(chunks), partial end -- Receive a message body, assuming that the header has already been read by -- recv_header. The handling is sensitive to the request method -- and the status code of the response. local function recv_body(s, response, method, partial) local connection_close, connection_keepalive local version_major, version_minor local transfer_encoding local content_length local err partial = partial or "" -- First check for Connection: close and Connection: keep-alive. This is -- necessary to handle some servers that don't follow the protocol. connection_close = false connection_keepalive = false if response.header.connection then local offset, token offset = 0 while true do offset, token = get_token(response.header.connection, offset + 1) if not offset then break end if string.lower(token) == "close" then connection_close = true elseif string.lower(token) == "keep-alive" then connection_keepalive = true end end end -- The HTTP version may also affect our decisions. version_major, version_minor = string.match(response["status-line"], "^HTTP/(%d+)%.(%d+)") -- See RFC 2616, section 4.4 "Message Length". -- 1. Any response message which "MUST NOT" include a message-body (such as -- the 1xx, 204, and 304 responses and any response to a HEAD request) is -- always terminated by the first empty line after the header fields... -- -- Despite the above, some servers return a body with response to a HEAD -- request. So if an HTTP/1.0 server returns a response without Connection: -- keep-alive, or any server returns a response with Connection: close, read -- whatever's left on the socket (should be zero bytes). if string.upper(method) == "HEAD" or (response.status >= 100 and response.status <= 199) or response.status == 204 or response.status == 304 then if connection_close or (version_major == "1" and version_minor == "0" and not connection_keepalive) then return recv_all(s, partial) else return "", partial end end -- 2. If a Transfer-Encoding header field (section 14.41) is present and has -- any value other than "identity", then the transfer-length is defined by -- use of the "chunked" transfer-coding (section 3.6), unless the message -- is terminated by closing the connection. if response.header["transfer-encoding"] and response.header["transfer-encoding"] ~= "identity" then return recv_chunked(s, partial) end -- The Citrix XML Service sends a wrong "Transfer-Coding" instead of -- "Transfer-Encoding". if response.header["transfer-coding"] and response.header["transfer-coding"] ~= "identity" then return recv_chunked(s, partial) end -- 3. If a Content-Length header field (section 14.13) is present, its decimal -- value in OCTETs represents both the entity-length and the -- transfer-length. The Content-Length header field MUST NOT be sent if -- these two lengths are different (i.e., if a Transfer-Encoding header -- field is present). If a message is received with both a -- Transfer-Encoding header field and a Content-Length header field, the -- latter MUST be ignored. if response.header["content-length"] and not response.header["transfer-encoding"] then content_length = tonumber(response.header["content-length"]) if not content_length then return nil, string.format("Content-Length %q is non-numeric", response.header["content-length"]) end return recv_length(s, content_length, partial) end -- 4. If the message uses the media type "multipart/byteranges", and the -- ransfer-length is not otherwise specified, then this self- elimiting -- media type defines the transfer-length. [sic] -- Case 4 is unhandled. -- 5. By the server closing the connection. return recv_all(s, partial) end -- Sets response["status-line"] and response.status. local function parse_status_line(status_line, response) local version, status, reason_phrase response["status-line"] = status_line version, status, reason_phrase = string.match(status_line, "^HTTP/(%d%.%d) *(%d+) *(.*)\r?\n$") if not version then return nil, string.format("Error parsing status-line %q.", status_line) end -- We don't have a use for the version; ignore it. response.status = tonumber(status) if not response.status then return nil, string.format("Status code is not numeric: %s", status) end return true end -- Sets response.header and response.rawheader. local function parse_header(header, response) local pos local name, words local s, e response.header = {} response.rawheader = stdnse.strsplit("\r?\n", header) pos = 1 while pos <= #header do -- Get the field name. e, name = get_token(header, pos) if not name or e > #header or string.sub(header, e, e) ~= ":" then return nil, string.format("Can't get header field name at %q", string.sub(header, pos, pos + 30)) end pos = e + 1 -- Skip initial space. pos = skip_lws(header, pos) -- Get non-space words separated by LWS, then join them with a single space. words = {} while pos <= #header and not string.match(header, "^\r?\n", pos) do s = pos while not string.match(header, "^[ \t]", pos) and not string.match(header, "^\r?\n", pos) do pos = pos + 1 end words[#words + 1] = string.sub(header, s, pos - 1) pos = skip_lws(header, pos) end -- Set it in our table. name = string.lower(name) if response.header[name] then response.header[name] = response.header[name] .. ", " .. table.concat(words, " ") else response.header[name] = table.concat(words, " ") end -- Next field, or end of string. (If not it's an error.) s, e = string.find(header, "^\r?\n", pos) if not e then return nil, string.format("Header field named %q didn't end with CRLF", name) end pos = e + 1 end return true end -- Parse the contents of a Set-Cookie header field. The result is an array -- containing tables of the form -- -- { name = "NAME", value = "VALUE", Comment = "...", Domain = "...", ... } -- -- Every key except "name" and "value" is optional. -- -- This function attempts to support the cookie syntax defined in RFC 2109 -- along with the backwards-compatibility suggestions from its section 10, -- "HISTORICAL". Values need not be quoted, but if they start with a quote they -- will be interpreted as a quoted string. local function parse_set_cookie(s) local cookies local name, value local _, pos cookies = {} pos = 1 while true do local cookie = {} -- Get the NAME=VALUE part. pos = skip_space(s, pos) pos, cookie.name = get_token(s, pos) if not cookie.name then return nil, "Can't get cookie name." end pos = skip_space(s, pos) if pos > #s or string.sub(s, pos, pos) ~= "=" then return nil, string.format("Expected '=' after cookie name \"%s\".", cookie.name) end pos = pos + 1 pos = skip_space(s, pos) if string.sub(s, pos, pos) == "\"" then pos, cookie.value = get_quoted_string(s, pos) else _, pos, cookie.value = string.find(s, "([^;]*)[ \t]*", pos) pos = pos + 1 end if not cookie.value then return nil, string.format("Can't get value of cookie named \"%s\".", cookie.name) end pos = skip_space(s, pos) -- Loop over the attributes. while pos <= #s and string.sub(s, pos, pos) == ";" do pos = pos + 1 pos = skip_space(s, pos) pos, name = get_token(s, pos) if not name then return nil, string.format("Can't get attribute name of cookie \"%s\".", cookie.name) end pos = skip_space(s, pos) if pos <= #s and string.sub(s, pos, pos) == "=" then pos = pos + 1 pos = skip_space(s, pos) if string.sub(s, pos, pos) == "\"" then pos, value = get_quoted_string(s, pos) else -- account for the possibility of the expires attribute being empty or improperly formatted local last_pos = pos if string.lower(name) == "expires" then -- For version 0 cookies we must allow one comma for "expires". _, pos, value = string.find(s, "([^,]*,[^;,]*)[ \t]*", pos) else _, pos, value = string.find(s, "([^;,]*)[ \t]*", pos) end -- account for the possibility of the expires attribute being empty or improperly formatted if ( not(pos) ) then _, pos, value = s:find("([^;]*)", last_pos) end pos = pos + 1 end if not value then return nil, string.format("Can't get value of cookie attribute \"%s\".", name) end else value = true end cookie[name:lower()] = value pos = skip_space(s, pos) end cookies[#cookies + 1] = cookie if pos > #s then break end if string.sub(s, pos, pos) ~= "," then return nil, string.format("Syntax error after cookie named \"%s\".", cookie.name) end pos = pos + 1 pos = skip_space(s, pos) end return cookies end -- Read one response from the socket s and return it after -- parsing. local function next_response(s, method, partial) local response local status_line, header, body local status, err partial = partial or "" response = { status=nil, ["status-line"]=nil, header={}, rawheader={}, body="" } status_line, partial = recv_line(s, partial) if not status_line then return nil, partial end status, err = parse_status_line(status_line, response) if not status then return nil, err end header, partial = recv_header(s, partial) if not header then return nil, partial end status, err = parse_header(header, response) if not status then return nil, err end body, partial = recv_body(s, response, method, partial) if not body then return nil, partial end response.body = body -- We have the Status-Line, header, and body; now do any postprocessing. response.cookies = {} if response.header["set-cookie"] then response.cookies, err = parse_set_cookie(response.header["set-cookie"]) if not response.cookies then -- Ignore a cookie parsing error. response.cookies = {} end end return response, partial end --- Tries to extract the max number of requests that should be made on -- a keep-alive connection based on "Keep-Alive: timeout=xx,max=yy" response -- header. -- -- If the value is not available, an arbitrary value is used. If the connection -- is not explicitly closed by the server, this same value is attempted. -- -- @param response The http response - Might be a table or a raw response -- @return The max number of requests on a keep-alive connection local function getPipelineMax(response) -- Allow users to override this with a script-arg local pipeline = stdnse.get_script_args({'http.pipeline', 'pipeline'}) if(pipeline) then return tonumber(pipeline) end if response then if response.header and response.header.connection ~= "close" then if response.header["keep-alive"] then local max = string.match( response.header["keep-alive"], "max=(%d*)") if(max == nil) then return 40 end return tonumber(max) else return 40 end end end return 1 end --- Builds a string to be added to the request mod_options table -- -- @param cookies A cookie jar just like the table returned parse_set_cookie. -- @param path If the argument exists, only cookies with this path are included to the request -- @return A string to be added to the mod_options table local function buildCookies(cookies, path) local cookie = "" if type(cookies) == 'string' then return cookies end for i, ck in ipairs(cookies or {}) do if not path or string.match(ck["path"],".*" .. path .. ".*") then if i ~= 1 then cookie = cookie .. " " end cookie = cookie .. ck["name"] .. "=" .. ck["value"] .. ";" end end return cookie end -- HTTP cache. -- Cache of GET and HEAD requests. Uses <"host:port:path", record>. -- record is in the format: -- result: The result from http.get or http.head -- last_used: The time the record was last accessed or made. -- get: Was the result received from a request to get or recently wiped? -- size: The size of the record, equal to #record.result.body. local cache = {size = 0}; local function check_size (cache) local max_size = tonumber(stdnse.get_script_args({'http.max-cache-size', 'http-max-cache-size'}) or 1e6); local size = cache.size; if size > max_size then stdnse.print_debug(1, "Current http cache size (%d bytes) exceeds max size of %d", size, max_size); table.sort(cache, function(r1, r2) return (r1.last_used or 0) < (r2.last_used or 0); end); for i, record in ipairs(cache) do if size <= max_size then break end local result = record.result; if type(result.body) == "string" then size = size - record.size; record.size, record.get, result.body = 0, false, ""; end end cache.size = size; end stdnse.print_debug(2, "Final http cache size (%d bytes) of max size of %d", size, max_size); return size; end -- Unique value to signal value is being retrieved. -- Also holds pairs, working thread is value local WORKING = setmetatable({}, {__mode = "v"}); local function lookup_cache (method, host, port, path, options) if(not(validate_options(options))) then return nil end options = options or {}; local bypass_cache = options.bypass_cache; -- do not lookup local no_cache = options.no_cache; -- do not save result local no_cache_body = options.no_cache_body; -- do not save body if type(port) == "table" then port = port.number end local key = stdnse.get_hostname(host)..":"..port..":"..path; local mutex = nmap.mutex(tostring(lookup_cache)..key); local state = { mutex = mutex, key = key, method = method, bypass_cache = bypass_cache, no_cache = no_cache, no_cache_body = no_cache_body, }; while true do mutex "lock"; local record = cache[key]; if bypass_cache or record == nil or method ~= record.method then WORKING[mutex] = coroutine.running(); cache[key], state.old_record = WORKING, record; return nil, state; elseif record == WORKING then local working = WORKING[mutex]; if working == nil or coroutine.status(working) == "dead" then -- thread died before insert_cache could be called cache[key] = nil; -- reset end mutex "done"; else mutex "done"; record.last_used = os.time(); return tcopy(record.result), state; end end end local function response_is_cacheable(response) -- if response.status is nil, then an error must have occured during the request -- and we probably don't want to cache the response if not response.status then return false end -- 206 Partial Content. RFC 2616, 1.34: "...a cache that does not support the -- Range and Content-Range headers MUST NOT cache 206 (Partial Content) -- responses." if response.status == 206 then return false end -- RFC 2616, 13.4. "A response received with any [status code other than 200, -- 203, 206, 300, 301 or 410] (e.g. status codes 302 and 307) MUST NOT be -- returned in a reply to a subsequent request unless there are cache-control -- directives or another header(s) that explicitly allow it." -- We violate the standard here and allow these other codes to be cached, -- with the exceptions listed below. -- 401 Unauthorized. Caching this would prevent us from retrieving it later -- with the correct credentials. if response.status == 401 then return false end return true end local function insert_cache (state, response) local key = assert(state.key); local mutex = assert(state.mutex); if response == nil or state.no_cache or not response_is_cacheable(response) then cache[key] = state.old_record; else local record = { result = tcopy(response), last_used = os.time(), method = state.method, size = type(response.body) == "string" and #response.body or 0, }; response = record.result; -- only modify copy cache[key], cache[#cache+1] = record, record; if state.no_cache_body then response.body = ""; end if type(response.body) == "string" then cache.size = cache.size + #response.body; check_size(cache); end end mutex "done"; end -- Return true if the given method requires a body in the request. In case no -- body was supplied we must send "Content-Length: 0". local function request_method_needs_content_length(method) return method == "POST" end -- For each of the following request functions, host may either be -- a string or a table, and port may either be a number or a -- table. -- -- The format of the return value is a table with the following structure: -- {status = 200, status-line = "HTTP/1.1 200 OK", header = {}, rawheader = {}, body ="..."} -- The header table has an entry for each received header with the header name -- being the key. The table also has an entry named "status" which contains the -- http status code of the request. -- In case of an error, the status is nil and status-line describes the problem. local function http_error(status_line) return { status = nil, ["status-line"] = status_line, header = {}, rawheader = {}, body = nil, } end --- Build an HTTP request from parameters and return it as a string. -- -- @param host The host this request is intended for. -- @param port The port this request is intended for. -- @param method The method to use. -- @param path The path for the request. -- @param options A table of options, which may include the keys: -- * header: A table containing additional headers to be used for the request. -- * content: The content of the message (content-length will be added -- set header['Content-Length'] to override) -- * cookies: A table of cookies in the form returned by parse_set_cookie. -- * auth: A table containing the keys username and password. -- @return A request string. -- @see generic_request local function build_request(host, port, method, path, options) if(not(validate_options(options))) then return nil end options = options or {} -- Private copy of the options table, used to add default header fields. local mod_options = { header = { Connection = "close", Host = get_host_field(host, port), ["User-Agent"] = USER_AGENT } } if options.cookies then local cookies = buildCookies(options.cookies, path) if #cookies > 0 then mod_options.header["Cookie"] = cookies end end if options.auth and not options.auth.digest then local username = options.auth.username local password = options.auth.password local credentials = "Basic " .. base64.enc(username .. ":" .. password) mod_options.header["Authorization"] = credentials end if options.digestauth then local order = {"username", "realm", "nonce", "digest-uri", "algorithm", "response", "qop", "nc", "cnonce"} local no_quote = {algorithm=true, qop=true, nc=true} local creds = {} for _,k in ipairs(order) do local v = options.digestauth[k] if v then if no_quote[k] then table.insert(creds, ("%s=%s"):format(k,v)) else if k == "digest-uri" then table.insert(creds, ('%s="%s"'):format("uri",v)) else table.insert(creds, ('%s="%s"'):format(k,v)) end end end end local credentials = "Digest "..table.concat(creds, ", ") mod_options.header["Authorization"] = credentials end local body -- Build a form submission from a table, like "k1=v1&k2=v2". if type(options.content) == "table" then local parts = {} local k, v for k, v in pairs(options.content) do parts[#parts + 1] = url.escape(k) .. "=" .. url.escape(v) end body = table.concat(parts, "&") mod_options.header["Content-Type"] = "application/x-www-form-urlencoded" elseif options.content then body = options.content elseif request_method_needs_content_length(method) then body = "" end if body then mod_options.header["Content-Length"] = #body end -- Add any other header fields into the local copy. table_augment(mod_options, options) -- We concat this string manually to allow null bytes in requests local request_line = method.." "..path.." HTTP/1.1" local header = {} for name, value in pairs(mod_options.header) do -- we concat this string manually to allow null bytes in requests header[#header + 1] = name..": "..value end return request_line .. "\r\n" .. stdnse.strjoin("\r\n", header) .. "\r\n\r\n" .. (body or "") end --- Send a string to a host and port and return the HTTP result. This function -- is like generic_request, to be used when you have a ready-made -- request, not a collection of request parameters. -- -- @param host The host to connect to. -- @param port The port to connect to. -- @param options A table of other parameters. It may have any of these fields: -- * timeout: A timeout used for socket operations. -- * header: A table containing additional headers to be used for the request. -- * content: The content of the message (content-length will be added -- set header['Content-Length'] to override) -- * cookies: A table of cookies in the form returned by parse_set_cookie. -- * auth: A table containing the keys username and password. -- @return A response table, see module documentation for description. -- @see generic_request local function request(host, port, data, options) if(not(validate_options(options))) then return http_error("Options failed to validate.") end local method local header local response options = options or {} if type(port) == 'table' then if port.protocol and port.protocol ~= 'tcp' then stdnse.print_debug(1, "http.request() supports the TCP protocol only, your request to %s cannot be completed.", host) return http_error("Unsupported protocol.") end end method = string.match(data, "^(%S+)") local socket, partial, opts = comm.tryssl(host, port, data, { timeout = options.timeout }) if not socket then return http_error("Error creating socket.") end repeat response, partial = next_response(socket, method, partial) if not response then return http_error("There was an error in next_response function.") end -- See RFC 2616, sections 8.2.3 and 10.1.1, for the 100 Continue status. -- Sometimes a server will tell us to "go ahead" with a POST body before -- sending the real response. If we got one of those, skip over it. until not (response.status >= 100 and response.status <= 199) socket:close() -- if SSL was used to retrieve the URL mark this in the response response.ssl = ( opts == 'ssl' ) return response end ---Do a single request with a given method. The response is returned as the standard -- response table (see the module documentation). -- -- The get, head, and post functions are simple -- wrappers around generic_request. -- -- Any 1XX (informational) responses are discarded. -- -- @param host The host to connect to. -- @param port The port to connect to. -- @param method The method to use; for example, 'GET', 'HEAD', etc. -- @param path The path to retrieve. -- @param options [optional] A table that lets the caller control socket timeouts, HTTP headers, and other parameters. For full documentation, see the module documentation (above). -- @return A response table, see module documentation for description. -- @see request function generic_request(host, port, method, path, options) if(not(validate_options(options))) then return http_error("Options failed to validate.") end local digest_auth = options and options.auth and options.auth.digest if digest_auth and not have_ssl then stdnse.print_debug("http: digest auth requires openssl.") end if digest_auth and have_ssl then -- If we want to do digest authentication, we have to make an initial -- request to get realm, nonce and other fields. local options_with_auth_removed = tcopy(options) options_with_auth_removed["auth"] = nil local r = generic_request(host, port, method, path, options_with_auth_removed) local h = r.header['www-authenticate'] if not r.status or (h and not string.find(h:lower(), "digest.-realm")) then stdnse.print_debug("http: the target doesn't support digest auth or there was an error during request.") return http_error("The target doesn't support digest auth or there was an error during request.") end -- Compute the response hash local dmd5 = sasl.DigestMD5:new(h, options.auth.username, options.auth.password, method, path) local _, digest_table = dmd5:calcDigest() options.digestauth = digest_table end return request(host, port, build_request(host, port, method, path, options), options) end ---Uploads a file using the PUT method and returns a result table. This is a simple wrapper -- around generic_request -- -- @param host The host to connect to. -- @param port The port to connect to. -- @param path The path to retrieve. -- @param options [optional] A table that lets the caller control socket timeouts, HTTP headers, and other parameters. For full documentation, see the module documentation (above). -- @param putdata The contents of the file to upload -- @return A response table, see module documentation for description. -- @see http.generic_request function put(host, port, path, options, putdata) if(not(validate_options(options))) then return http_error("Options failed to validate.") end if ( not(putdata) ) then return http_error("No file to PUT.") end local mod_options = { content = putdata, } table_augment(mod_options, options or {}) return generic_request(host, port, "PUT", path, mod_options) end -- Check if the given URL is okay to redirect to. Return a table with keys -- "host", "port", and "path" if okay, nil otherwise. -- @param url table as returned by url.parse -- @param host table as received by the action function -- @param port table as received by the action function -- @return loc table containing the new location function redirect_ok(host, port) -- A battery of tests a URL is subjected to in order to decide if it may be -- redirected to. They incrementally fill in loc.host, loc.port, and loc.path. local rules = { -- Check if there's any credentials in the url function (url, host, port) -- bail if userinfo is present return ( url.userinfo and false ) or true end, -- Check if the location is within the domain or host function (url, host, port) local hostname = stdnse.get_hostname(host) if ( hostname == host.ip and host.ip == url.host.ip ) then return true end local domain = hostname:match("^[^%.]-%.(.*)") or hostname local match = ("^.*%s$"):format(domain) if ( url.host:match(match) ) then return true end return false end, -- Check whether the new location has the same port number function (url, host, port) -- port fixup, adds default ports 80 and 443 in case no url.port was -- defined, we do this based on the url scheme local url_port = url.port if ( not(url_port) ) then if ( url.scheme == "http" ) then url_port = 80 elseif( url.scheme == "https" ) then url_port = 443 end end if (not url_port) or tonumber(url_port) == port.number then return true end return false end, -- Check whether the url.scheme matches the port.service function (url, host, port) -- if url.scheme is present then it must match the scanned port if url.scheme and url.port then return true end if url.scheme and url.scheme ~= port.service then return false end return true end, -- make sure we're actually being redirected somewhere and not to the same url function (url, host, port) -- path cannot be unchanged unless host has changed -- loc.path must be set if returning true if ( not url.path or url.path == "/" ) and url.host == ( host.targetname or host.ip) then return false end if not url.path then return true end return true end, } local counter = MAX_REDIRECT_COUNT -- convert a numeric port to a table if ( "number" == type(port) ) then port = { number = port } end return function(url) if ( counter == 0 ) then return false end counter = counter - 1 for i, rule in ipairs( rules ) do if ( not(rule( url, host, port )) ) then --stdnse.print_debug("Rule failed: %d", i) return false end end return true end end -- Handles a HTTP redirect -- @param host table as received by the script action function -- @param port table as received by the script action function -- @param path string -- @param response table as returned by http.get or http.head -- @return url table as returned by url.parse or nil if there's no -- redirect taking place local function parse_redirect(host, port, path, response) if ( not(tostring(response.status):match("^30[127]$")) or not(response.header) or not(response.header.location) ) then return nil end port = ( "number" == type(port) ) and { number = port } or port local u = url.parse(response.header.location) if ( not(u.host) and not(u.scheme) ) then -- we're dealing with a relative url u.host, u.port = stdnse.get_hostname(host), port.number u.path = ((u.path:sub(1,1) == "/" and "" ) or "/" ) .. u.path -- ensuring leading slash end if ( not(u.path) ) then u.path = "/" end if ( u.query ) then u.path = ("%s?%s"):format( u.path, u.query ) end -- do port fixup if ( not(u.port) ) then if ( u.scheme == "http" ) then u.port = 80 end if ( u.scheme == "https") then u.port = 443 end end return u end -- Retrieves the correct function to use to validate HTTP redirects -- @param host table as received by the action function -- @param port table as received by the action function -- @param options table as passed to http.get or http.head -- @return redirect_ok function used to validate HTTP redirects local function get_redirect_ok(host, port, options) if ( options ) then if ( options.redirect_ok == false ) then return function() return false end elseif( "function" == type(options.redirect_ok) ) then return options.redirect_ok(host, port) else return redirect_ok(host, port) end else return redirect_ok(host, port) end end ---Fetches a resource with a GET request and returns the result as a table. This is a simple -- wraper around generic_request, with the added benefit of having local caching -- and support for HTTP redirects. Redirects are followed only if they pass all the -- validation rules of the redirect_ok function. This function may be overrided by supplying -- a custom function in the redirect_ok field of the options array. The default -- function redirects the request if the destination is: -- * Within the same host or domain -- * Has the same port number -- * Stays within the current scheme -- * Does not exceed MAX_REDIRECT_COUNT count of redirects -- -- Caching and redirects can be controlled in the options array, see module -- documentation for more information. -- -- @param host The host to connect to. -- @param port The port to connect to. -- @param path The path to retrieve. -- @param options [optional] A table that lets the caller control socket timeouts, HTTP headers, and other parameters. For full documentation, see the module documentation (above). -- @return A response table, see module documentation for description. -- @see http.generic_request function get(host, port, path, options) if(not(validate_options(options))) then return http_error("Options failed to validate.") end local redir_check = get_redirect_ok(host, port, options) local response, state, location local u = { host = host, port = port, path = path } repeat response, state = lookup_cache("GET", u.host, u.port, u.path, options); if ( response == nil ) then response = generic_request(u.host, u.port, "GET", u.path, options) insert_cache(state, response); end u = parse_redirect(host, port, path, response) if ( not(u) ) then break end location = location or {} table.insert(location, response.header.location) until( not(redir_check(u)) ) response.location = location return response end ---Parses a URL and calls http.get with the result. The URL can contain -- all the standard fields, protocol://host:port/path -- -- @param u The URL of the host. -- @param options [optional] A table that lets the caller control socket timeouts, HTTP headers, and other parameters. For full documentation, see the module documentation (above). -- @return A response table, see module documentation for description. -- @see http.get function get_url( u, options ) if(not(validate_options(options))) then return http_error("Options failed to validate.") end local parsed = url.parse( u ) local port = {} port.service = parsed.scheme port.number = parsed.port if not port.number then if parsed.scheme == 'https' then port.number = 443 else port.number = 80 end end local path = parsed.path or "/" if parsed.query then path = path .. "?" .. parsed.query end return get( parsed.host, port, path, options ) end ---Fetches a resource with a HEAD request. Like get, this is a simple -- wrapper around generic_request with response caching. This function -- also has support for HTTP redirects. Redirects are followed only if they pass -- all the validation rules of the redirect_ok function. This function may be -- overrided by supplying a custom function in the redirect_ok field -- of the options array. The default function redirects the request if the -- destination is: -- * Within the same host or domain -- * Has the same port number -- * Stays within the current scheme -- * Does not exceed MAX_REDIRECT_COUNT count of redirects -- -- Caching and redirects can be controlled in the options array, -- see module documentation for more information. -- -- @param host The host to connect to. -- @param port The port to connect to. -- @param path The path to retrieve. -- @param options [optional] A table that lets the caller control socket timeouts, HTTP headers, and other parameters. For full documentation, see the module documentation (above). -- @return A response table, see module documentation for description. -- @see http.generic_request function head(host, port, path, options) if(not(validate_options(options))) then return http_error("Options failed to validate.") end local redir_check = get_redirect_ok(host, port, options) local response, state, location local u = { host = host, port = port, path = path } repeat response, state = lookup_cache("HEAD", host, port, path, options); if response == nil then response = generic_request(host, port, "HEAD", path, options) insert_cache(state, response); end u = parse_redirect(host, port, path, response) if ( not(u) ) then break end location = location or {} table.insert(location, response.header.location) until( not(redir_check(u)) ) response.location = location return response end ---Fetches a resource with a POST request. Like get, this is a simple -- wrapper around generic_request except that postdata is handled -- properly. -- -- @param host The host to connect to. -- @param port The port to connect to. -- @param path The path to retrieve. -- @param options [optional] A table that lets the caller control socket timeouts, HTTP headers, and other parameters. For full documentation, see the module documentation (above). -- @param ignored Ignored for backwards compatibility. -- @param postdata A string or a table of data to be posted. If a table, the keys and values must be strings, and they will be encoded into an application/x-www-form-encoded form submission. -- @return A response table, see module documentation for description. -- @see http.generic_request function post( host, port, path, options, ignored, postdata ) if(not(validate_options(options))) then return http_error("Options failed to validate.") end local mod_options = { content = postdata, } table_augment(mod_options, options or {}) return generic_request(host, port, "POST", path, mod_options) end -- Deprecated pipeline functions function pGet( host, port, path, options, ignored, allReqs ) stdnse.print_debug(1, "WARNING: pGet() is deprecated. Use pipeline_add() instead.") return pipeline_add(path, options, allReqs, 'GET') end function pHead( host, port, path, options, ignored, allReqs ) stdnse.print_debug(1, "WARNING: pHead() is deprecated. Use pipeline_add instead.") return pipeline_add(path, options, allReqs, 'HEAD') end function addPipeline(host, port, path, options, ignored, allReqs, method) stdnse.print_debug(1, "WARNING: addPipeline() is deprecated! Use pipeline_add instead.") return pipeline_add(path, options, allReqs, method) end function pipeline(host, port, allReqs) stdnse.print_debug(1, "WARNING: pipeline() is deprecated. Use pipeline_go() instead.") return pipeline_go(host, port, allReqs) end ---Adds a pending request to the HTTP pipeline. The HTTP pipeline is a set of requests that will -- all be sent at the same time, or as close as the server allows. This allows more efficient -- code, since requests are automatically buffered and sent simultaneously. -- -- The all_requests argument contains the current list of queued requests (if this -- is the first time calling pipeline_add, it should be nil). After -- adding the request to end of the queue, the queue is returned and can be passed to the next -- pipeline_add call. -- -- When all requests have been queued, call pipeline_go with the all_requests table -- that has been built. -- -- @param path The path to retrieve. -- @param options [optional] A table that lets the caller control socket timeouts, HTTP headers, and other parameters. For full documentation, see the module documentation (above). -- @param all_requests [optional] The current pipeline queue (retunred from a previous add_pipeline call), or nil if it's the first call. -- @param method [optional] The HTTP method ('get', 'head', 'post', etc). Default: 'get'. -- @return Table with the pipeline get requests (plus this new one) -- @see http.pipeline_go function pipeline_add(path, options, all_requests, method) if(not(validate_options(options))) then return nil end method = method or 'GET' all_requests = all_requests or {} local mod_options = { header = { ["Connection"] = "keep-alive" } } table_augment(mod_options, options or {}) local object = { method=method, path=path, options=mod_options } table.insert(all_requests, object) return all_requests end ---Performs all queued requests in the all_requests variable (created by the -- pipeline_add function). Returns an array of responses, each of -- which is a table as defined in the module documentation above. -- -- @param host The host to connect to. -- @param port The port to connect to. -- @param all_requests A table with all the previously built pipeline requests -- @return A list of responses, in the same order as the requests were queued. Each response is a table as described in the module documentation. function pipeline_go(host, port, all_requests) stdnse.print_debug("Total number of pipelined requests: " .. #all_requests) local responses local response local partial responses = {} -- Check for an empty request if (#all_requests == 0) then stdnse.print_debug(1, "Warning: empty set of requests passed to http.pipeline()") return responses end local socket, bopt -- We'll try a first request with keep-alive, just to check if the server -- supports and how many requests we can send into one socket! local request = build_request(host, port, all_requests[1].method, all_requests[1].path, all_requests[1].options) socket, partial, bopt = comm.tryssl(host, port, request, {connect_timeout=5000, request_timeout=3000, recv_before=false}) if not socket then return nil end response, partial = next_response(socket, all_requests[1].method, partial) if not response then return nil end table.insert(responses, response) local limit = getPipelineMax(response) -- how many requests to send on one connection limit = limit > #all_requests and #all_requests or limit local max_pipeline = stdnse.get_script_args("http.max-pipeline") or limit -- how many requests should be pipelined local count = 1 stdnse.print_debug(1, "Number of requests allowed by pipeline: " .. limit) while #responses < #all_requests do local j, batch_end -- we build a table with many requests, upper limited by the var "limit" local requests = {} if #responses + limit < #all_requests then batch_end = #responses + limit else batch_end = #all_requests end j = #responses + 1 while j <= batch_end do if j == batch_end then all_requests[j].options.header["Connection"] = "close" end if j~= batch_end and all_requests[j].options.header["Connection"] ~= 'keep-alive' then all_requests[j].options.header["Connection"] = 'keep-alive' end table.insert(requests, build_request(host, port, all_requests[j].method, all_requests[j].path, all_requests[j].options)) -- to avoid calling build_request more then one time on the same request, -- we might want to build all the requests once, above the main while loop j = j + 1 end if count >= limit or not socket:get_info() then socket:connect(host, port, bopt) partial = "" count = 0 end socket:set_timeout(10000) local start = 1 local len = #requests local req_sent = 0 -- start sending the requests and pipeline them in batches of max_pipeline elements while start <= len do stdnse.print_debug(2, "HTTP pipeline: number of requests in current batch: %d, already sent: %d, responses from current batch: %d, all responses received: %d",len,start-1,count,#responses) local req = {} if max_pipeline == limit then req = requests else for i=start,start+max_pipeline-1,1 do table.insert(req, requests[i]) end end local num_req = #req req = table.concat(req, "") start = start + max_pipeline socket:send(req) req_sent = req_sent + num_req local inner_count = 0 local fail = false -- collect responses for the last batch while inner_count < num_req and #responses < #all_requests do response, partial = next_response(socket, all_requests[#responses + 1].method, partial) if not response then stdnse.print_debug("HTTP pipeline: there was a problem while receiving responses.") stdnse.print_debug(3, "The request was:\n%s",req) fail = true break end count = count + 1 inner_count = inner_count + 1 responses[#responses + 1] = response end if fail then break end end socket:close() if count == 0 then stdnse.print_debug("Received 0 of %d expected responses.\nGiving up on pipeline.", limit); break elseif count < req_sent then stdnse.print_debug("Received only %d of %d expected responses.\nDecreasing max pipelined requests to %d.", count, req_sent, count) limit = count end end stdnse.print_debug("Number of received responses: " .. #responses) return responses end -- Parsing of specific headers. skip_space and the read_* functions return the -- byte index following whatever they have just read, or nil on error. -- Skip whitespace (that has already been folded from LWS). See RFC 2616, -- section 2.2, definition of LWS. local function skip_space(s, pos) local _ _, pos = string.find(s, "^[ \t]*", pos) return pos + 1 end -- See RFC 2616, section 2.2. local function read_token(s, pos) local _, token pos = skip_space(s, pos) -- 1*. CHAR is only byte values 0-127. _, pos, token = string.find(s, "^([^\0\001-\031()<>@,;:\\\"/?={} \t%[%]\127-\255]+)", pos) if token then return pos + 1, token else return nil end end -- See RFC 2616, section 2.2. Here we relax the restriction that TEXT may not -- contain CTLs. local function read_quoted_string(s, pos) local chars = {} if string.sub(s, pos, pos) ~= "\"" then return nil end pos = pos + 1 pos = skip_space(s, pos) while pos <= #s and string.sub(s, pos, pos) ~= "\"" do local c c = string.sub(s, pos, pos) if c == "\\" then if pos < #s then pos = pos + 1 c = string.sub(s, pos, pos) else return nil end end chars[#chars + 1] = c pos = pos + 1 end if pos > #s or string.sub(s, pos, pos) ~= "\"" then return nil end return pos + 1, table.concat(chars) end local function read_token_or_quoted_string(s, pos) pos = skip_space(s, pos) if string.sub(s, pos, pos) == "\"" then return read_quoted_string(s, pos) else return read_token(s, pos) end end --- -- Finds forms in html code -- returns table of found forms, in plaintext. -- @param body A response.body in which to search for forms -- @return A list of forms. function grab_forms(body) local forms = {} if not body then return forms end local form_start_expr = '<%s*[Ff][Oo][Rr][Mm]' local form_end_expr = '' local form_opening = string.find(body, form_start_expr) local forms = {} while form_opening do local form_closing = string.find(body, form_end_expr, form_opening+1) if form_closing == nil then --html code contains errors break end forms[#forms+1] = string.sub(body, form_opening, form_closing-1) if form_closing+1 <= #body then form_opening = string.find(body, form_start_expr, form_closing+1) else break end end return forms end --- -- Parses a form, that is, finds its action and fields. -- @param form A plaintext representation of form -- @return A dictionary with keys:

action,
-- method if one is specified, fields
-- which is a list of fields found in the form each of which has a
-- name attribute and type if specified.
function parse_form(form)
  local parsed = {}
  local fields = {}
  local form_action = string.match(form, '[Aa][Cc][Tt][Ii][Oo][Nn]="(.-)"')
  if form_action then
    parsed["action"] = form_action
  else
    return nil
  end
  
  -- determine if the form is using get or post
  local form_method = string.match(form, '[Mm][Ee][Tt][Hh][Oo][Dd]="(.-)"')
  if form_method then
    parsed["method"] = string.lower(form_method)
  end

  -- now identify the fields
  local input_type
  local input_name

  -- first find regular inputs
  for f in string.gmatch(form, '<%s*[Ii][Nn][Pp][Uu][Tt].->') do
    input_type = string.match(f, '[Tt][Yy][Pp][Ee]="(.-)"')
    input_name = string.match(f, '[Nn][Aa][Mm][Ee]="(.-)"')
    local next_field_index = #fields+1
    if input_name then
      fields[next_field_index] = {}
      fields[next_field_index]["name"] = input_name
      if input_type then
        fields[next_field_index]["type"] = string.lower(input_type)
      end
    end
  end

  -- now search for textareas
  for f in string.gmatch(form, '<%s*[Tt][Ee][Xx][Tt][Aa][Rr][Ee][Aa].->') do
    input_name = string.match(f, '[Nn][Aa][Mm][Ee]="(.-)"')
    local next_field_index = #fields+1
    if input_name then
      fields[next_field_index] = {}
      fields[next_field_index]["name"] = input_name
      fields[next_field_index]["type"] = "textarea"
    end
  end
  parsed["fields"] = fields
  return parsed
end

local MONTH_MAP = {
  Jan = 1, Feb = 2, Mar = 3, Apr = 4, May = 5, Jun = 6,
  Jul = 7, Aug = 8, Sep = 9, Oct = 10, Nov = 11, Dec = 12
}

--- Parses an HTTP date string, in any of the following formats from section
-- 3.3.1 of RFC 2616:
-- * Sun, 06 Nov 1994 08:49:37 GMT  (RFC 822, updated by RFC 1123)
-- * Sunday, 06-Nov-94 08:49:37 GMT (RFC 850, obsoleted by RFC 1036)
-- * Sun Nov  6 08:49:37 1994       (ANSI C's asctime() format)
-- @param s the date string.
-- @return a table with keys year, month,
-- day, hour, min, sec, and
-- isdst, relative to GMT, suitable for input to
-- os.time.
function parse_date(s)
  local day, month, year, hour, min, sec, tz, month_name

  -- Handle RFC 1123 and 1036 at once.
  day, month_name, year, hour, min, sec, tz = s:match("^%w+, (%d+)[- ](%w+)[- ](%d+) (%d+):(%d+):(%d+) (%w+)$")
  if not day then
    month_name, day, hour, min, sec, year = s:match("%w+ (%w+)  ?(%d+) (%d+):(%d+):(%d+) (%d+)")
    tz = "GMT"
  end
  if not day then
    stdnse.print_debug(1, "http.parse_date: can't parse date \"%s\": unknown format.", s)
    return nil
  end
  -- Look up the numeric code for month.
  month = MONTH_MAP[month_name]
  if not month then
    stdnse.print_debug(1, "http.parse_date: unknown month name \"%s\".", month_name)
    return nil
  end
  if tz ~= "GMT" then
    stdnse.print_debug(1, "http.parse_date: don't know time zone \"%s\", only \"GMT\".", tz)
    return nil
  end
  day = tonumber(day)
  year = tonumber(year)
  hour = tonumber(hour)
  min = tonumber(min)
  sec = tonumber(sec)

  if year < 100 then
    -- Two-digit year. Make a guess.
    if year < 70 then
      year = year + 2000
    else
      year = year + 1900
    end
  end

  return { year = year, month = month, day = day, hour = hour, min = min, sec = sec, isdst = false }
end

-- See RFC 2617, section 1.2. This function returns a table with keys "scheme"
-- and "params".
local function read_auth_challenge(s, pos)
  local _, scheme, params

  pos, scheme = read_token(s, pos)
  if not scheme then
    return nil
  end

  params = {}
  pos = skip_space(s, pos)
  while pos < #s do
    local name, val
    local tmp_pos

    -- We need to peek ahead at this point. It's possible that we've hit the
    -- end of one challenge and the beginning of another. Section 14.33 says
    -- that the header value can be 1#challenge, in other words several
    -- challenges separated by commas. Because the auth-params are also
    -- separated by commas, the only way we can tell is if we find a token not
    -- followed by an equals sign.
    tmp_pos = pos
    tmp_pos, name = read_token(s, tmp_pos)
    if not name then
      pos = skip_space(s, pos + 1)
      return pos, { scheme = scheme, params = nil }
    end
    tmp_pos = skip_space(s, tmp_pos)
    if string.sub(s, tmp_pos, tmp_pos) ~= "=" then
      -- No equals sign, must be the beginning of another challenge.
      break
    end
    tmp_pos = tmp_pos + 1

    pos = tmp_pos
    pos, val = read_token_or_quoted_string(s, pos)
    if not val then
      return nil
    end
    if params[name] then
      return nil
    end
    params[name] = val
    pos = skip_space(s, pos)
    if string.sub(s, pos, pos) == "," then
      pos = skip_space(s, pos + 1)
      if pos > #s then
        return nil
      end
    end
  end

  return pos, { scheme = scheme, params = params }
end

---Parses the WWW-Authenticate header as described in RFC 2616, section 14.47
-- and RFC 2617, section 1.2. The return value is an array of challenges. Each
-- challenge is a table with the keys scheme and
-- params.
-- @param s The header value text.
-- @return An array of challenges, or nil on error.
function parse_www_authenticate(s)
  local challenges = {}
  local pos

  pos = 1
  while pos <= #s do
    local challenge

    pos, challenge = read_auth_challenge(s, pos)
    if not challenge then
      return nil
    end
    challenges[#challenges + 1] = challenge
  end

  return challenges
end


---Take the data returned from a HTTP request and return the status string.
-- Useful for stdnse.print_debug messages and even advanced output.
--
-- @param data The response table from any HTTP request
-- @return The best status string we could find: either the actual status string, the status code, or "".
function get_status_string(data)
  -- Make sure we have valid data
  if(data == nil) then
    return ""
  elseif(data['status-line'] == nil) then
    if(data['status'] ~= nil) then
      return data['status']
    end

    return ""
  end

  -- We basically want everything after the space
  local space = string.find(data['status-line'], ' ')
  if(space == nil) then
    return data['status-line']
  else
    return (string.sub(data['status-line'], space + 1)):gsub('\r?\n', '')
  end
end

---Determine whether or not the server supports HEAD by requesting / and
-- verifying that it returns 200, and doesn't return data. We implement the
-- check like this because can't always rely on OPTIONS to tell the truth.
--
-- Note: If identify_404 returns a 200 status, HEAD requests
-- should be disabled. Sometimes, servers use a 200 status code with a message
-- explaining that the page wasn't found. In this case, to actually identify
-- a 404 page, we need the full body that a HEAD request doesn't supply. 
-- This is determined automatically if the result_404 field is
-- set. 
--
-- @param host The host object.
-- @param port The port to use.
-- @param result_404 [optional] The result when an unknown page is requested.
-- This is returned by identify_404. If the 404 page returns a
-- 200 code, then we disable HEAD requests.
-- @param path The path to request; by default, / is used.
-- @return A boolean value: true if HEAD is usable, false otherwise.
-- @return If HEAD is usable, the result of the HEAD request is returned (so
-- potentially, a script can avoid an extra call to HEAD
function can_use_head(host, port, result_404, path)
  -- If the 404 result is 200, don't use HEAD.
  if(result_404 == 200) then
    return false
  end

  -- Default path
  if(path == nil) then
    path = '/'
  end

  -- Perform a HEAD request and see what happens.
  local data = head( host, port, path )
  if data then
    if data.status and data.status == 302 and data.header and data.header.location then
      stdnse.print_debug(1, "HTTP: Warning: Host returned 302 and not 200 when performing HEAD.")
      return false
    end

    if data.status and data.status == 200 and data.header then
      -- check that a body wasn't returned
      if #data.body > 0 then
        stdnse.print_debug(1, "HTTP: Warning: Host returned data when performing HEAD.")
        return false
      end

      stdnse.print_debug(1, "HTTP: Host supports HEAD.")
      return true, data
    end

    stdnse.print_debug(1, "HTTP: Didn't receive expected response to HEAD request (got %s).", get_status_string(data))
    return false
  end

  stdnse.print_debug(1, "HTTP: HEAD request completely failed.")
  return false
end

--- Try and remove anything that might change within a 404. For example:
-- * A file path (includes URI)
-- * A time
-- * A date
-- * An execution time (numbers in general, really)
--
-- The intention is that two 404 pages from different URIs and taken hours
-- apart should, whenever possible, look the same.
--
-- During this function, we're likely going to over-trim things. This is fine
-- -- we want enough to match on that it'll a) be unique, and b) have the best
-- chance of not changing. Even if we remove bits and pieces from the file, as
-- long as it isn't a significant amount, it'll remain unique.
--
-- One case this doesn't cover is if the server generates a random haiku for
-- the user.
--
-- @param body The body of the page.
function clean_404(body)
  if ( not(body) ) then
    return
  end

  -- Remove anything that looks like time
  body = string.gsub(body, '%d?%d:%d%d:%d%d', "")
  body = string.gsub(body, '%d%d:%d%d', "")
  body = string.gsub(body, 'AM', "")
  body = string.gsub(body, 'am', "")
  body = string.gsub(body, 'PM', "")
  body = string.gsub(body, 'pm', "")

  -- Remove anything that looks like a date (this includes 6 and 8 digit numbers)
  -- (this is probably unnecessary, but it's getting pretty close to 11:59 right now, so you never know!)
  body = string.gsub(body, '%d%d%d%d%d%d%d%d', "") -- 4-digit year (has to go first, because it overlaps 2-digit year)
  body = string.gsub(body, '%d%d%d%d%-%d%d%-%d%d', "")
  body = string.gsub(body, '%d%d%d%d/%d%d/%d%d', "")
  body = string.gsub(body, '%d%d%-%d%d%-%d%d%d%d', "")
  body = string.gsub(body, '%d%d%/%d%d%/%d%d%d%d', "")

  body = string.gsub(body, '%d%d%d%d%d%d', "") -- 2-digit year
  body = string.gsub(body, '%d%d%-%d%d%-%d%d', "")
  body = string.gsub(body, '%d%d%/%d%d%/%d%d', "")

  -- Remove anything that looks like a path (note: this will get the URI too) (note2: this interferes with the date removal above, so it can't be moved up)
  body = string.gsub(body, "/[^ ]+", "") -- Unix - remove everything from a slash till the next space
  body = string.gsub(body, "[a-zA-Z]:\\[^ ]+", "") -- Windows - remove everything from a "x:\" pattern till the next space

  -- If we have SSL available, save us a lot of memory by hashing the page (if SSL isn't available, this will work fine, but
  -- take up more memory). If we're debugging, don't hash (it makes things far harder to debug).
  if(have_ssl and nmap.debugging() == 0) then
    return openssl.md5(body)
  end

  return body
end

---Try requesting a non-existent file to determine how the server responds to
-- unknown pages ("404 pages"), which a) tells us what to expect when a
-- non-existent page is requested, and b) tells us if the server will be
-- impossible to scan. If the server responds with a 404 status code, as it is
-- supposed to, then this function simply returns 404. If it contains one of a
-- series of common status codes, including unauthorized, moved, and others, it
-- is returned like a 404.
--
-- I (Ron Bowes) have observed one host that responds differently for three
-- scenarios:
-- * A non-existent page, all lowercase (a login page)
-- * A non-existent page, with uppercase (a weird error page that says, "Filesystem is corrupt.")
-- * A page in a non-existent directory (a login page with different font colours)
--
-- As a result, I've devised three different 404 tests, one to check each of
-- these conditions. They all have to match, the tests can proceed; if any of
-- them are different, we can't check 404s properly.
--
-- @param host The host object.
-- @param port The port to which we are establishing the connection.
-- @return status Did we succeed?
-- @return result If status is false, result is an error message. Otherwise, it's the code to expect (typically, but not necessarily, '404').
-- @return body Body is a hash of the cleaned-up body that can be used when detecting a 404 page that doesn't return a 404 error code.
function identify_404(host, port)
  local data
  local bad_responses = { 301, 302, 400, 401, 403, 499, 501, 503 }

  -- The URLs used to check 404s
  local URL_404_1 = '/nmaplowercheck' .. os.time(os.date('*t'))
  local URL_404_2 = '/NmapUpperCheck' .. os.time(os.date('*t'))
  local URL_404_3 = '/Nmap/folder/check' .. os.time(os.date('*t'))

  data = get(host, port, URL_404_1)

  if(data == nil) then
    stdnse.print_debug(1, "HTTP: Failed while testing for 404 status code")
    return false, "Failed while testing for 404 error message"
  end

  if(data.status and data.status == 404) then
    stdnse.print_debug(1, "HTTP: Host returns proper 404 result.")
    return true, 404
  end

  if(data.status and data.status == 200) then
    stdnse.print_debug(1, "HTTP: Host returns 200 instead of 404.")

    -- Clean up the body (for example, remove the URI). This makes it easier to validate later
    if(data.body) then
      -- Obtain a couple more 404 pages to test different conditions
      local data2 = get(host, port, URL_404_2)
      local data3 = get(host, port, URL_404_3)
      if(data2 == nil or data3 == nil) then
        stdnse.print_debug(1, "HTTP: Failed while testing for extra 404 error messages")
        return false, "Failed while testing for extra 404 error messages"
      end

      -- Check if the return code became something other than 200.
      -- Status code: -1 represents unknown.
      -- If the status is nil or the string "unknown" we switch to -1. 
      if(data2.status ~= 200) then
        if(type(data2.status) ~= "number") then
          data2.status = -1
        end
        stdnse.print_debug(1, "HTTP: HTTP 404 status changed for second request (became %d).", data2.status)
        return false, string.format("HTTP 404 status changed for second request (became %d).", data2.status)
      end

      -- Check if the return code became something other than 200
      if(data3.status ~= 200) then
        if(type(data3.status) ~= "number") then
          data3.status = -1
        end
        stdnse.print_debug(1, "HTTP: HTTP 404 status changed for third request (became %d).", data3.status)
        return false, string.format("HTTP 404 status changed for third request (became %d).", data3.status)
      end

      -- Check if the returned bodies (once cleaned up) matches the first returned body
      local clean_body  = clean_404(data.body)
      local clean_body2 = clean_404(data2.body)
      local clean_body3 = clean_404(data3.body)
      if(clean_body ~= clean_body2) then
        stdnse.print_debug(1, "HTTP: Two known 404 pages returned valid and different pages; unable to identify valid response.")
        stdnse.print_debug(1, "HTTP: If you investigate the server and it's possible to clean up the pages, please post to nmap-dev mailing list.")
        return false, string.format("Two known 404 pages returned valid and different pages; unable to identify valid response.")
      end

      if(clean_body ~= clean_body3) then
        stdnse.print_debug(1, "HTTP: Two known 404 pages returned valid and different pages; unable to identify valid response (happened when checking a folder).")
        stdnse.print_debug(1, "HTTP: If you investigate the server and it's possible to clean up the pages, please post to nmap-dev mailing list.")
        return false, string.format("Two known 404 pages returned valid and different pages; unable to identify valid response (happened when checking a folder).")
      end

      return true, 200, clean_body
    end

    stdnse.print_debug(1, "HTTP: The 200 response didn't contain a body.")
    return true, 200
  end

  -- Loop through any expected error codes
  for _,code in pairs(bad_responses) do
    if(data.status and data.status == code) then
      stdnse.print_debug(1, "HTTP: Host returns %s instead of 404 File Not Found.", get_status_string(data))
      return true, code
    end
  end

  stdnse.print_debug(1,  "Unexpected response returned for 404 check: %s", get_status_string(data))

  return true, data.status
end

--- Determine whether or not the page that was returned is a 404 page. This is
--actually a pretty simple function, but it's best to keep this logic close to
--identify_404, since they will generally be used together.
--
-- @param data The data returned by the HTTP request
-- @param result_404 The status code to expect for non-existent pages. This is returned by identify_404.
-- @param known_404 The 404 page itself, if result_404 is 200. If result_404 is something else, this parameter is ignored and can be set to nil. This is returned by identify_404.
-- @param page The page being requested (used in error messages).
-- @param displayall [optional] If set to true, don't exclude non-404 errors (such as 500). 
-- @return A boolean value: true if the page appears to exist, and false if it does not.
function page_exists(data, result_404, known_404, page, displayall)
  if(data and data.status) then
    -- Handle the most complicated case first: the "200 Ok" response
    if(data.status == 200) then
      if(result_404 == 200) then
        -- If the 404 response is also "200", deal with it (check if the body matches)
        if(#data.body == 0) then
          -- I observed one server that returned a blank string instead of an error, on some occasions
          stdnse.print_debug(1, "HTTP: Page returned a totally empty body; page likely doesn't exist")
          return false
        elseif(clean_404(data.body) ~= known_404) then
          stdnse.print_debug(1, "HTTP: Page returned a body that doesn't match known 404 body, therefore it exists (%s)", page)
          return true
        else
          return false
        end
      else
        -- If 404s return something other than 200, and we got a 200, we're good to go
        stdnse.print_debug(1, "HTTP: Page was '%s', it exists! (%s)", get_status_string(data), page)
        return true
      end
    else
      -- If the result isn't a 200, check if it's a 404 or returns the same code as a 404 returned
      if(data.status ~= 404 and data.status ~= result_404) then
        -- If this check succeeded, then the page isn't a standard 404 -- it could be a redirect, authentication request, etc. Unless the user
        -- asks for everything (with a script argument), only display 401 Authentication Required here.
        stdnse.print_debug(1, "HTTP: Page didn't match the 404 response (%s) (%s)", get_status_string(data), page)

        if(data.status == 401) then -- "Authentication Required"
          return true
        elseif(displayall) then
          return true
        end

        return false
      else
        -- Page was a 404, or looked like a 404
        return false
      end
    end
  else
    stdnse.print_debug(1, "HTTP: HTTP request failed (is the host still up?)")
    return false
  end
end

---Check if the response variable, which could be a return from a http.get, http.post, http.pipeline, 
-- etc, contains the given text. The text can be:
-- * Part of a header ('content-type', 'text/html', '200 OK', etc)
-- * An entire header ('Content-type: text/html', 'Content-length: 123', etc)
-- * Part of the body
--
-- The search text is treated as a Lua pattern. 
--
--@param response The full response table from a HTTP request.
--@param pattern The pattern we're searching for. Don't forget to escape '-', for example, 'Content%-type'. The pattern can also contain captures, like 'abc(.*)def', which will be returned if successful. 
--@param case_sensitive [optional] Set to true for case-sensitive searches. Default: not case sensitive.
--@return result True if the string matched, false otherwise
--@return matches An array of captures from the match, if any
function response_contains(response, pattern, case_sensitive)
  local result, _
  local m = {}
  
  -- If they're searching for the empty string or nil, it's true
  if(pattern == '' or pattern == nil) then
    return true
  end

  -- Create a function that either lowercases everything or doesn't, depending on case sensitivity
  local case = function(pattern) return string.lower(pattern or '') end
  if(case_sensitive == true) then
    case = function(pattern) return (pattern or '') end
  end

  -- Set the case of the pattern
  pattern = case(pattern)

  -- Check the status line (eg, 'HTTP/1.1 200 OK')
  m = {string.match(case(response['status-line']), pattern)};
  if(m and #m > 0) then
    return true, m
  end

  -- Check the headers
  for _, header in pairs(response['rawheader']) do
    m = {string.match(case(header), pattern)}
    if(m and #m > 0) then
      return true, m
    end
  end

  -- Check the body
  m = {string.match(case(response['body']), pattern)}
  if(m and #m > 0) then
    return true, m
  end

  return false
end

---Take a URI or URL in any form and convert it to its component parts. The URL can optionally
-- have a protocol definition ('http://'), a server ('scanme.insecure.org'), a port (':80'), a
-- URI ('/test/file.php'), and a query string ('?username=ron&password=turtle'). At the minimum,
-- a path or protocol and url are required. 
--
--@param url The incoming URL to parse
--@return result A table containing the result, which can have the following fields: protocol, hostname, port, uri, querystring. All fields are strings except querystring, which is a table containing name=value pairs.
function parse_url(url)
  local result = {}

  -- Save the original URL
  result['original'] = url

  -- Split the protocol off, if it exists
  local colonslashslash = string.find(url, '://')
  if(colonslashslash) then
    result['protocol'] = string.sub(url, 1, colonslashslash - 1)
    url = string.sub(url, colonslashslash + 3)
  end

  -- Split the host:port from the path
  local slash, host_port
  slash = string.find(url, '/')
  if(slash) then
    host_port      = string.sub(url, 1, slash - 1)
    result['path_query'] = string.sub(url, slash)
  else
    -- If there's no slash, then it's just a URL (if it has a http://) or a path (if it doesn't)
    if(result['protocol']) then
      result['host_port'] = url
    else
      result['path_query'] = url
    end
  end
  if(host_port == '') then
    host_port = nil
  end

  -- Split the host and port apart, if possible
  if(host_port) then
    local colon = string.find(host_port, ':')
    if(colon) then
      result['host'] = string.sub(host_port, 1, colon - 1)
      result['port'] = tonumber(string.sub(host_port, colon + 1))
    else
      result['host'] = host_port
    end
  end

  -- Split the path and querystring apart
  if(result['path_query']) then
    local question = string.find(result['path_query'], '?')
    if(question) then
      result['path']      = string.sub(result['path_query'], 1, question - 1)
      result['raw_querystring'] = string.sub(result['path_query'], question + 1)
    else
      result['path'] = result['path_query']
    end

    -- Split up the query, if necessary
    if(result['raw_querystring']) then
      result['querystring'] = {}
      local values = stdnse.strsplit('&', result['raw_querystring'])
      for i, v in ipairs(values) do
        local name, value = table.unpack(stdnse.strsplit('=', v))
        result['querystring'][name] = value
      end
    end

    -- Get the extension of the file, if any, or set that it's a folder
    if(string.match(result['path'], "/$")) then
      result['is_folder'] = true
    else
      result['is_folder'] = false
      local split_str = stdnse.strsplit('%.', result['path'])
      if(split_str and #split_str > 1) then
        result['extension'] = split_str[#split_str]
      end
    end
  end

  return result
end

---This function should be called whenever a valid path (a path that doesn't contain a known
-- 404 page) is discovered. It will add the path to the registry in several ways, allowing
-- other scripts to take advantage of it in interesting ways. 
--
--@param host The host the path was discovered on (not necessarily the host being scanned). 
--@param port The port the path was discovered on (not necessarily the port being scanned). 
--@param path The path discovered. Calling this more than once with the same path is okay; it'll update the data as much as possible instead of adding a duplicate entry
--@param status [optional] The status code (200, 404, 500, etc). This can be left off if it isn't known. 
--@param links_to [optional] A table of paths that this page links to. 
--@param linked_from [optional] A table of paths that link to this page. 
--@param contenttype [optional] The content-type value for the path, if it's known. 
function save_path(host, port, path, status, links_to, linked_from, contenttype)
  -- Make sure we have a proper hostname and port
  host = stdnse.get_hostname(host)
  if(type(port) == 'table') then
    port = port.number
  end

  -- Parse the path
  local parsed = parse_url(path)

  -- Add to the 'all_pages' key
  stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'all_pages'}, parsed['path'])

  -- Add the URL with querystring to all_pages_full_query
  stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'all_pages_full_query'}, parsed['path_query'])

  -- Add the URL to a key matching the response code
  if(status) then
    stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'status_codes', status}, parsed['path'])
  end

  -- If it's a directory, add it to the directories list; otherwise, add it to the files list
  if(parsed['is_folder']) then
    stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'directories'}, parsed['path'])
  else
    stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'files'}, parsed['path'])
  end


  -- If we have an extension, add it to the extensions key
  if(parsed['extension']) then
    stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'extensions', parsed['extension']}, parsed['path'])
  end

  -- Add an entry for the page and its arguments
  if(parsed['querystring']) then
    -- Add all scripts with a querystring to the 'cgi' and 'cgi_full_query' keys
    stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'cgi'}, parsed['path'])
    stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'cgi_full_query'}, parsed['path_query'])

    -- Add the query string alone to the registry (probably not necessary)
    stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'cgi_querystring', parsed['path'] }, parsed['raw_querystring'])

    -- Add the individual arguments for the page, along with their values
    for key, value in pairs(parsed['querystring']) do
      stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'cgi_args', parsed['path']}, parsed['querystring'])
    end
  end

  -- Save the pages it links to
  if(links_to) then
    if(type(links_to) == 'string') then
      links_to = {links_to}
    end

    for _, v in ipairs(links_to) do
      stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'links_to', parsed['path_query']}, v)
    end
  end

  -- Save the pages it's linked from (we save these in the 'links_to' key, reversed)
  if(linked_from) then
    if(type(linked_from) == 'string') then
      linked_from = {linked_from}
    end

    for _, v in ipairs(linked_from) do
      stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'links_to', v}, parsed['path_query'])
    end
  end

  -- Save it as a content-type, if we have one
  if(contenttype) then
    stdnse.registry_add_array({parsed['host'] or host, 'www', parsed['port'] or port, 'content-type', contenttype}, parsed['path_query'])
  end
end

local function get_default_timeout( nmap_timing )
  local timeout = {}
  if nmap_timing >= 0 and nmap_timing <= 3 then
    timeout.connect = 10000
    timeout.request = 15000
  end
  if nmap_timing >= 4 then
    timeout.connect = 5000
    timeout.request = 10000
  end
  if nmap_timing >= 5 then
    timeout.request = 7000
  end
  return timeout
end


return _ENV;