1 files changed, 115 insertions, 0 deletions
diff --git a/scripts/http-proxy-brute.nse b/scripts/http-proxy-brute.nse
new file mode 100644
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--- /dev/null
+++ b/scripts/http-proxy-brute.nse
@@ -0,0 +1,115 @@
+local base64 = require "base64"
+local brute = require "brute"
+local creds = require "creds"
+local http = require "http"
+local shortport = require "shortport"
+local stdnse = require "stdnse"
+
+description = [[
+Performs brute force password guessing against HTTP proxy servers.
+]]
+
+---
+-- @usage
+-- nmap --script http-proxy-brute -p 8080 <host>
+--
+-- @output
+-- PORT     STATE SERVICE
+-- 8080/tcp open  http-proxy
+-- | http-proxy-brute:
+-- |   Accounts
+-- |     patrik:12345 - Valid credentials
+-- |   Statistics
+-- |_    Performed 6 guesses in 2 seconds, average tps: 3
+--
+-- @args http-proxy-brute.url sets an alternative URL to use when brute forcing
+--       (default: http://scanme.insecure.org)
+-- @args http-proxy-brute.method changes the HTTP method to use when performing
+--       brute force guessing (default: HEAD)
+
+author = "Patrik Karlsson"
+license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
+
+-- maybe the script does not need to be in the external category
+-- as most request should not "leave" the proxy.
+categories = {"brute", "intrusive", "external"}
+
+
+portrule = shortport.port_or_service({8123,3128,8000,8080},{'polipo','squid-http','http-proxy'})
+
+local arg_url = stdnse.get_script_args(SCRIPT_NAME .. '.url') or 'http://scanme.nmap.org/'
+local arg_method = stdnse.get_script_args(SCRIPT_NAME .. '.method') or "HEAD"
+
+Driver = {
+
+  new = function(self, host, port)
+    local o = { host = host, port = port }
+    setmetatable(o, self)
+    self.__index = self
+    return o
+  end,
+
+  connect = function( self )
+    return true
+  end,
+
+  login = function( self, username, password )
+
+    -- the http library does not yet support proxy authentication, so let's
+    -- do what's necessary here.
+    local header = { ["Proxy-Authorization"] = "Basic " .. base64.enc(username .. ":" .. password) }
+    local response = http.generic_request(self.host, self.port, arg_method, arg_url, { header = header, bypass_cache = true } )
+
+    -- if we didn't get a 407 error, assume the credentials
+    -- were correct. we should probably do some more checks here
+    if ( response.status ~= 407 ) then
+      return true, creds.Account:new( username, password, creds.State.VALID)
+    end
+
+    return false, brute.Error:new( "Incorrect password" )
+  end,
+
+  disconnect = function( self )
+    return true
+  end,
+}
+
+-- checks whether the proxy really needs authentication and that the
+-- authentication mechanism can be handled by our script, currently only
+-- BASIC authentication is supported.
+local function checkProxy(host, port, url)
+  local response = http.generic_request(host, port, arg_method, url, { bypass_cache = true })
+
+  if ( response.status ~= 407 ) then
+    return false, "Proxy server did not require authentication"
+  end
+
+  local proxy_auth = response.header["proxy-authenticate"]
+  if ( not(proxy_auth) ) then
+    return false, "No proxy authentication header was found"
+  end
+
+  local challenges = http.parse_www_authenticate(proxy_auth)
+
+  for _, challenge in ipairs(challenges) do
+    if ( "Basic" == challenge.scheme ) then
+      return true
+    end
+  end
+  return false, "The authentication scheme wasn't supported"
+end
+
+action = function(host, port)
+
+  local status, err = checkProxy(host, port, arg_url)
+  if ( not(status) ) then
+    return stdnse.format_output(false, err)
+  end
+
+  local engine = brute.Engine:new(Driver, host, port)
+  engine.options.script_name = SCRIPT_NAME
+  local result
+  status, result = engine:start()
+
+  return result
+end