Add FTP protocol client implementation

lib/rex/proto/ftp/client.rb

@@ -0,0 +1,290 @@
+# -*- coding: binary -*-
+
+require 'rex/socket'
+
+module Rex
+module Proto
+module Ftp
+
+###
+#
+# Acts as a client to an FTP server
+# See the RFC: https://www.w3.org/Protocols/rfc959/
+#
+###
+class Client
+
+  #
+  # Creates a new client instance.
+  #
+  def initialize(host, port = 21, ssl = nil, ssl_version = nil, proxies = nil, username = '', password = '', verbose = false)
+    self.hostname = host
+    self.port     = port.to_i
+    self.context  = context
+    self.ssl      = ssl
+    self.ssl_version = ssl_version
+    self.proxies  = proxies
+    self.username = username
+    self.password = password
+    self.verbose  = verbose
+  end
+
+  #
+  # This method estabilishes a connection to the host on the port
+  # defined in opts{}, if the connection is successful, the method
+  # returns a socket which can be used to communicate with the client
+  #
+  def connect
+    nsock = Rex::Socket::Tcp.create(
+      'PeerHost'      =>  self.hostname,
+      'PeerPort'      =>  self.port,
+      'LocalHost'     => "0.0.0.0",
+      'LocalPort'     =>  0.to_i,
+      'SSL'           =>  self.ssl,
+      'SSLVersion'    =>  self.ssl_version,
+      'Proxies'       => self.proxies
+    )
+    self.sock=nsock
+    self.banner = recv_ftp_resp(nsock)
+    print_status("Connected to target FTP server.") if self.verbose
+    return nsock
+  end
+
+
+  #
+  # This method reads an FTP response based on FTP continuation
+  #
+  def recv_ftp_resp(nsock = self.sock)
+    found_end = false
+    resp = ""
+    left = ""
+    if !@ftpbuff.empty?
+      left << @ftpbuff
+      @ftpbuff = ""
+    end
+    while true
+      data = nsock.get_once(-1, ftp_timeout)
+      if not data
+        @ftpbuff << resp
+        @ftpbuff << left
+        return data
+      end
+
+      got = left + data
+      left = ""
+
+      # handle the end w/o newline case
+      enlidx = got.rindex(0x0a.chr)
+      if enlidx != (got.length-1)
+        if not enlidxhttps:
+          left << got
+          next
+        else
+          left << got.slice!((enlidx+1)..got.length)
+        end
+      end
+
+      # split into lines
+      rarr = got.split(/\r?\n/)
+      rarr.each do |ln|
+        if not found_end
+          resp << ln
+          resp << "\r\n"
+          if ln.length > 3 and ln[3,1] == ' '
+            found_end = true
+          end
+        else
+          left << ln
+          left << "\r\n"
+        end
+      end
+      if found_end
+        @ftpbuff << left
+        print_status("FTP recv: #{resp.inspect}") if self.verbose
+        return resp
+      end
+    end
+  end
+
+  #
+  # This method transmits a FTP command and does not wait for a response
+  #
+  def raw_send(cmd, nsock = self.sock)
+    print_status("FTP send: #{cmd.inspect}") if self.verbose
+    nsock.put(cmd)
+  end
+
+  #
+  # This method transmits a FTP command and waits for a response.  If one is
+  # received, it is returned to the caller.
+  #
+  def raw_send_recv(cmd, nsock = self.sock)
+    nsock.put(cmd)
+    nsock.get_once(-1, ftp_timeout)
+  end
+
+  #
+  # This method uses the senduser and sendpass methods defined below
+  # in order to login to the ftp server
+  #
+  def connect_login
+    ftpsock = connect
+
+    if !(self.user and self.pass)
+      print_error("No username and password were supplied, unable to login")
+      return false
+    end
+
+    print_status("Authenticating as #{user} with password #{pass}...") if self.verbose
+    res = send_user(user, ftpsock)
+
+    if (res !~ /^(331|2)/)
+      print_error("The server rejected our username") if self.verbose
+      return false
+    end
+
+    if (pass)
+      print_status("Sending password...") if self.verbose
+      res = send_pass(pass, ftpsock)
+      if (res !~ /^2/)
+        print_error("The server rejected our password") if self.verbose
+        return false
+      end
+    end
+
+    return true
+  end
+
+  #
+  # This method logs in as the supplied user by transmitting the FTP
+  # 'USER <user>' command.
+  #
+  def send_user(user, nsock = self.sock)
+    raw_send("USER #{user}\r\n", nsock)
+    recv_ftp_resp(nsock)
+  end
+
+  #
+  # This method completes user authentication by sending the supplied
+  # password using the FTP 'PASS <pass>' command.
+  #
+  def send_pass(pass, nsock = self.sock)
+    raw_send("PASS #{pass}\r\n", nsock)
+    recv_ftp_resp(nsock)
+  end
+
+  #
+  # This method handles establishing datasocket for data channel
+  #
+  def data_connect(mode = nil, nsock = self.sock)
+    if mode
+      res = send_cmd([ 'TYPE' , mode ], true, nsock)
+      return nil if not res =~ /^200/
+    end
+
+    # force datasocket to renegotiate
+    self.datasocket.shutdown if self.datasocket != nil
+
+    res = send_cmd(['PASV'], true, nsock)
+    return nil if not res =~ /^227/
+
+    # 227 Entering Passive Mode (127,0,0,1,196,5)
+    if res =~ /\((\d+)\,(\d+),(\d+),(\d+),(\d+),(\d+)/
+      # convert port to FTP syntax
+      datahost = "#{$1}.#{$2}.#{$3}.#{$4}"
+      dataport = ($5.to_i * 256) + $6.to_i
+      self.datasocket = Rex::Socket::Tcp.create(
+        'PeerHost' => datahost,
+        'PeerPort' => dataport
+      )
+    end
+    self.datasocket
+  end
+
+
+  #
+  # This method handles disconnecting our data channel
+  #
+  def data_disconnect
+    self.datasocket.shutdown if self.datasocket
+    self.datasocket = nil
+  end
+
+  #
+  # This method sends one command with zero or more parameters
+  #
+  def send_cmd(args, recv = true, nsock = self.sock)
+    cmd = args.join(" ") + "\r\n"
+    ret = raw_send(cmd, nsock)
+    if (recv)
+      return recv_ftp_resp(nsock)
+    end
+    return ret
+  end
+
+
+  #
+  # This method sends a QUIT command.
+  #
+  def send_quit(nsock = self.sock)
+    raw_send("QUIT\r\n", nsock)
+    recv_ftp_resp(nsock)
+  end
+
+  #
+  # Function implementing 'ls' or list files command
+  #
+  def ls
+    datasocket = data_connect()
+    send_cmd(["list"])
+    output = datasocket.get
+    data_disconnect()
+    return output
+  end
+
+  #
+  # Function implementing 'pwd' or present working directory command
+  #
+  def pwd
+    send_cmd(["pwd"])
+  end
+
+  #
+  # Function implementing 'cd' or change directory command
+  #
+  def cd(path)
+    send_cmd(["cwd "+path])
+  end
+
+  #
+  # Function implementing download command
+  #
+  def download(filename)
+    datasocket = data_connect()
+    send_cmd(["retr",filename])
+    output = datasocket.get
+    file = File.open(filename,"wb")
+    file.write(output)
+    file.close()
+    data_disconnect()
+  end
+
+  #
+  # Function implementing upload command
+  #
+  def upload
+    datasocket = data_connect()
+    file=File.open(filename,"rb")
+    data = file.read()
+    file.close()
+    send_cmd(["stor",filename])
+    datasocket.write(data)
+    data_disconnect()
+  end
+
+
+end
+
+end
+end
+end