metasploit-framework/lib/rex/proto/ftp/client.rb

347 lines
9.9 KiB
Ruby

# -*- 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
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 !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 !enlidx
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 !found_end
resp << ln
resp << "\r\n"
if ln.length > 3 && 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 && 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
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) + $6.to_i
self.datasocket = Rex::Socket::Tcp.create(
'PeerHost' => datahost,
'PeerPort' => dataport
)
end
self.datasocket
end
#
# This method handles disconnecting our data channel
#
def data_disconnect
self.datasocket.shutdown if self.datasocket
self.datasocket = nil
end
#
# This method sends one command with zero or more parameters
#
def send_cmd(args, recv = true, nsock = self.sock)
cmd = args.join(" ") + "\r\n"
ret = raw_send(cmd, nsock)
if recv
return recv_ftp_resp(nsock)
end
ret
end
#
# This method sends a QUIT command.
#
def send_quit(nsock = self.sock)
raw_send("QUIT\r\n", nsock)
recv_ftp_resp(nsock)
end
#
# This method transmits the command in args and receives / uploads DATA via data channel
# For commands not needing data, it will fall through to the original send_cmd
#
# For commands that send data only, the return will be the server response.
# For commands returning both data and a server response, an array will be returned.
#
# NOTE: This function always waits for a response from the server.
#
def send_cmd_data(args, data, mode = 'a', nsock = self.sock)
type = nil
# implement some aliases for various commands
if args[0] =~ /^DIR$/i || args[0] =~ /^LS$/i
# TODO || args[0] =~ /^MDIR$/i || args[0] =~ /^MLS$/i
args[0] = "LIST"
type = "get"
elsif args[0] =~ /^GET$/i
args[0] = "RETR"
type = "get"
elsif args[0] =~ /^PUT$/i
args[0] = "STOR"
type = "put"
end
# fall back if it's not a supported data command
if !type
return send_cmd(args, true, nsock)
end
# Set the transfer mode and connect to the remove server
return nil if !data_connect(mode)
# Our pending command should have got a connection now.
res = send_cmd(args, true, nsock)
# make sure could open port
return nil unless res =~ /^(150|125) /
# dispatch to the proper method
if type == "get"
# failed listings jsut disconnect..
begin
data = self.datasocket.get_once(-1, ftp_timeout)
rescue ::EOFError
data = nil
end
else
sent = self.datasocket.put(data)
end
# close data channel so command channel updates
data_disconnect
# get status of transfer
ret = nil
if type == "get"
ret = recv_ftp_resp(nsock)
ret = [ ret, data ]
else
ret = recv_ftp_resp(nsock)
end
ret
end
#
# Function implementing 'ls' or list files command
#
def ls
datasocket = data_connect
send_cmd(["list"])
output = datasocket.get
data_disconnect
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