metasploit-framework/lib/rex/post/meterpreter/client.rb

390 lines
9.0 KiB
Ruby

#!/usr/bin/env ruby
require 'socket'
require 'openssl'
require 'rex/script'
require 'rex/post/meterpreter/client_core'
require 'rex/post/meterpreter/channel'
require 'rex/post/meterpreter/channel_container'
require 'rex/post/meterpreter/dependencies'
require 'rex/post/meterpreter/object_aliases'
require 'rex/post/meterpreter/packet'
require 'rex/post/meterpreter/packet_parser'
require 'rex/post/meterpreter/packet_dispatcher'
module Rex
module Post
module Meterpreter
#
# Just to get it in there...
#
module Extensions
end
###
#
# This class represents a logical meterpreter client class. This class
# provides an interface that is compatible with the Rex post-exploitation
# interface in terms of the feature set that it attempts to expose. This
# class is meant to drive a single meterpreter client session.
#
###
class Client
include Rex::Post::Meterpreter::PacketDispatcher
include Rex::Post::Meterpreter::ChannelContainer
#
# Extension name to class hash.
#
@@ext_hash = {}
#
# Cached SSL certificate (required to scale)
#
@@ssl_ctx = nil
#
# Mutex to synchronize class-wide operations
#
@@ssl_mutex = ::Mutex.new
#
# Lookup the error that occurred
#
def self.lookup_error(code)
code
end
#
# Checks the extension hash to see if a class has already been associated
# with the supplied extension name.
#
def self.check_ext_hash(name)
@@ext_hash[name]
end
#
# Stores the name to class association for the supplied extension name.
#
def self.set_ext_hash(name, klass)
@@ext_hash[name] = klass
end
#
# Initializes the client context with the supplied socket through
# which communication with the server will be performed.
#
def initialize(sock,opts={})
init_meterpreter(sock, opts)
end
#
# Cleans up the meterpreter instance, terminating the dispatcher thread.
#
def cleanup_meterpreter
ext.aliases.each_value do | extension |
extension.cleanup if extension.respond_to?( 'cleanup' )
end
dispatcher_thread.kill if dispatcher_thread
end
#
# Initializes the meterpreter client instance
#
def init_meterpreter(sock,opts={})
self.sock = sock
self.parser = PacketParser.new
self.ext = ObjectAliases.new
self.ext_aliases = ObjectAliases.new
self.alive = true
self.target_id = opts[:target_id]
self.capabilities= opts[:capabilities] || {}
self.response_timeout = opts[:timeout] || self.class.default_timeout
self.send_keepalives = true
# Switch the socket to SSL mode and receive the hello if needed
if capabilities[:ssl] and not opts[:skip_ssl]
swap_sock_plain_to_ssl()
end
register_extension_alias('core', ClientCore.new(self))
initialize_inbound_handlers
initialize_channels
# Register the channel inbound packet handler
register_inbound_handler(Rex::Post::Meterpreter::Channel)
monitor_socket
end
def swap_sock_plain_to_ssl
# Create a new SSL session on the existing socket
ctx = generate_ssl_context()
ssl = OpenSSL::SSL::SSLSocket.new(sock, ctx)
if not ssl.respond_to?(:accept_nonblock)
ssl.accept
else
begin
ssl.accept_nonblock
# Ruby 1.8.7 and 1.9.0/1.9.1 uses a standard Errno
rescue ::Errno::EAGAIN, ::Errno::EWOULDBLOCK
IO::select(nil, nil, nil, 0.10)
retry
# Ruby 1.9.2+ uses IO::WaitReadable/IO::WaitWritable
rescue ::Exception => e
if ::IO.const_defined?('WaitReadable') and e.kind_of?(::IO::WaitReadable)
IO::select( [ ssl ], nil, nil, 0.10 )
retry
end
if ::IO.const_defined?('WaitWritable') and e.kind_of?(::IO::WaitWritable)
IO::select( nil, [ ssl ], nil, 0.10 )
retry
end
raise e
end
end
self.sock.extend(Rex::Socket::SslTcp)
self.sock.sslsock = ssl
self.sock.sslctx = ctx
tag = self.sock.get_once(-1, 30)
if(not tag or tag !~ /^GET \//)
raise RuntimeError, "Could not read the HTTP hello token"
end
end
def swap_sock_ssl_to_plain
# Remove references to the SSLSocket and Context
self.sock.sslsock.close
self.sock.sslsock = nil
self.sock.sslctx = nil
self.sock = self.sock.fd
self.sock.extend(::Rex::Socket::Tcp)
end
def generate_ssl_context
@@ssl_mutex.synchronize do
if not @@ssl_ctx
wlog("Generating SSL certificate for Meterpreter sessions")
key = OpenSSL::PKey::RSA.new(1024){ }
cert = OpenSSL::X509::Certificate.new
cert.version = 2
cert.serial = rand(0xFFFFFFFF)
subject = OpenSSL::X509::Name.new([
["C","US"],
['ST', Rex::Text.rand_state()],
["L", Rex::Text.rand_text_alpha(rand(20) + 10)],
["O", Rex::Text.rand_text_alpha(rand(20) + 10)],
["CN", self.sock.getsockname[1] || Rex::Text.rand_hostname],
])
issuer = OpenSSL::X509::Name.new([
["C","US"],
['ST', Rex::Text.rand_state()],
["L", Rex::Text.rand_text_alpha(rand(20) + 10)],
["O", Rex::Text.rand_text_alpha(rand(20) + 10)],
["CN", Rex::Text.rand_text_alpha(rand(20) + 10)],
])
cert.subject = subject
cert.issuer = issuer
cert.not_before = Time.now - (3600 * 365) + rand(3600 * 14)
cert.not_after = Time.now + (3600 * 365) + rand(3600 * 14)
cert.public_key = key.public_key
ef = OpenSSL::X509::ExtensionFactory.new(nil,cert)
cert.extensions = [
ef.create_extension("basicConstraints","CA:FALSE"),
ef.create_extension("subjectKeyIdentifier","hash"),
ef.create_extension("extendedKeyUsage","serverAuth"),
ef.create_extension("keyUsage","keyEncipherment,dataEncipherment,digitalSignature")
]
ef.issuer_certificate = cert
cert.add_extension ef.create_extension("authorityKeyIdentifier", "keyid:always,issuer:always")
cert.sign(key, OpenSSL::Digest::SHA1.new)
ctx = OpenSSL::SSL::SSLContext.new(:SSLv3)
ctx.key = key
ctx.cert = cert
ctx.session_id_context = Rex::Text.rand_text(16)
wlog("Generated SSL certificate for Meterpreter sessions")
@@ssl_ctx = ctx
end # End of if not @ssl_ctx
end # End of mutex.synchronize
@@ssl_ctx
end
##
#
# Accessors
#
##
#
# Returns the default timeout that request packets will use when
# waiting for a response.
#
def Client.default_timeout
return 300
end
##
#
# Alias processor
#
##
#
# Translates unhandled methods into registered extension aliases
# if a matching extension alias exists for the supplied symbol.
#
def method_missing(symbol, *args)
self.ext_aliases.aliases[symbol.to_s]
end
##
#
# Extension registration
#
##
#
# Loads the client half of the supplied extension and initializes it as a
# registered extension that can be reached through client.ext.[extension].
#
def add_extension(name)
# Check to see if this extension has already been loaded.
if ((klass = self.class.check_ext_hash(name.downcase)) == nil)
old = Rex::Post::Meterpreter::Extensions.constants
require("rex/post/meterpreter/extensions/#{name.downcase}/#{name.downcase}")
new = Rex::Post::Meterpreter::Extensions.constants
# No new constants added?
if ((diff = new - old).empty?)
diff = [ name.capitalize ]
end
klass = Rex::Post::Meterpreter::Extensions.const_get(diff[0]).const_get(diff[0])
# Save the module name to class association now that the code is
# loaded.
self.class.set_ext_hash(name.downcase, klass)
end
# Create a new instance of the extension
inst = klass.new(self)
self.ext.aliases[inst.name] = inst
return true
end
#
# Deregisters an extension alias of the supplied name.
#
def deregister_extension(name)
self.ext.aliases.delete(name)
end
#
# Enumerates all of the loaded extensions.
#
def each_extension(&block)
self.ext.aliases.each(block)
end
#
# Registers an aliased extension that can be referenced through
# client.name.
#
def register_extension_alias(name, ext)
self.ext_aliases.aliases[name] = ext
end
#
# Registers zero or more aliases that are provided in an array.
#
def register_extension_aliases(aliases)
aliases.each { |a|
register_extension_alias(a['name'], a['ext'])
}
end
#
# Deregisters a previously registered extension alias.
#
def deregister_extension_alias(name)
self.ext_aliases.aliases.delete(name)
end
#
# Dumps the extension tree.
#
def dump_extension_tree()
items = []
items.concat(self.ext.dump_alias_tree('client.ext'))
items.concat(self.ext_aliases.dump_alias_tree('client'))
return items.sort
end
#
# The extension alias under which all extensions can be accessed by name.
# For example:
#
# client.ext.stdapi
#
#
attr_reader :ext
#
# The socket the client is communicating over.
#
attr_reader :sock
#
# The timeout value to use when waiting for responses.
#
attr_accessor :response_timeout
#
# Whether to send pings every so often to determine liveness.
#
attr_accessor :send_keepalives
#
# Whether this session is alive. If the socket is disconnected or broken,
# this will be false
#
attr_accessor :alive
#
# The unique target identifier for this payload
#
attr_accessor :target_id
#
# The libraries available to this meterpreter server
#
attr_accessor :capabilities
protected
attr_accessor :parser, :ext_aliases # :nodoc:
attr_writer :ext, :sock # :nodoc:
end
end; end; end