583 lines
14 KiB
Ruby
583 lines
14 KiB
Ruby
require 'msf/core'
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require 'metasm'
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module Msf
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###
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#
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# This class represents the base class for a logical payload. The framework
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# automatically generates payload combinations at runtime which are all
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# extended for this Payload as a base class.
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#
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###
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class Payload < Msf::Module
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require 'rex/payloads'
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require 'msf/core/payload/single'
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require 'msf/core/payload/generic'
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require 'msf/core/payload/stager'
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# Platform specific includes
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require 'msf/core/payload/aix'
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require 'msf/core/payload/bsd'
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require 'msf/core/payload/linux'
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require 'msf/core/payload/osx'
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require 'msf/core/payload/solaris'
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require 'msf/core/payload/windows'
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require 'msf/core/payload/netware'
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require 'msf/core/payload/java'
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##
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#
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# Payload types
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#
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##
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module Type
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#
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# Single payload type. These types of payloads are self contained and
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# do not go through any staging.
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#
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Single = (1 << 0)
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#
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# The stager half of a staged payload. Its responsibility in life is to
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# read in the stage and execute it.
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#
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Stager = (1 << 1)
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#
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# The stage half of a staged payload. This payload performs whatever
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# arbitrary task it's designed to do, possibly making use of the same
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# connection that the stager used to read the stage in on, if
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# applicable.
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#
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Stage = (1 << 2)
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end
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#
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# Creates an instance of a payload module using the supplied information.
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#
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def initialize(info = {})
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super
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# If this is a staged payload but there is no stage information,
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# then this is actually a stager + single combination. Set up the
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# information hash accordingly.
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if self.class.include?(Msf::Payload::Single) and
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self.class.include?(Msf::Payload::Stager)
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self.module_info['Stage'] = {}
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if self.module_info['Payload']
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self.module_info['Stage']['Payload'] = self.module_info['Payload']['Payload'] || ""
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self.module_info['Stage']['Assembly'] = self.module_info['Payload']['Assembly'] || ""
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self.module_info['Stage']['Offsets'] = self.module_info['Payload']['Offsets'] || {}
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else
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self.module_info['Stage']['Payload'] = ""
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self.module_info['Stage']['Assembly'] = ""
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self.module_info['Stage']['Offsets'] = {}
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end
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@staged = true
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else
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@staged = false
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end
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# Update the module info hash with the connection type
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# that is derived from the handler for this payload. This is
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# used for compatibility filtering purposes.
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self.module_info['ConnectionType'] = connection_type
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end
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##
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#
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# Accessors
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#
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##
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#
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# Returns MODULE_PAYLOAD to indicate that this is a payload module.
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#
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def self.type
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return MODULE_PAYLOAD
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end
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#
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# Returns MODULE_PAYLOAD to indicate that this is a payload module.
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#
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def type
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return MODULE_PAYLOAD
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end
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#
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# Returns the string of bad characters for this payload, if any.
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#
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def badchars
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return self.module_info['BadChars']
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end
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#
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# The list of registers that should be saved by any NOP generators or
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# encoders, if possible.
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#
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def save_registers
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return self.module_info['SaveRegisters']
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end
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#
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# Returns the type of payload, either single or staged. Stage is
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# the default because singles and stagers are encouraged to include
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# the Single and Stager mixin which override the payload_type.
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#
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def payload_type
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return Type::Stage
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end
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#
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# Returns the string version of the payload type
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#
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def payload_type_s
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case payload_type
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when Type::Stage
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return "stage"
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when Type::Stager
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return "stager"
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when Type::Single
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return "single"
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else
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return "unknown"
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end
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end
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#
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# This method returns whether or not this payload uses staging.
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#
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def staged?
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(@staged or payload_type == Type::Stager or payload_type == Type::Stage)
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end
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#
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# Returns the payload's size. If the payload is staged, the size of the
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# first stage is returned.
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#
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def size
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pl = nil
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begin
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pl = generate()
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rescue NoCompatiblePayloadError
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end
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pl ||= ''
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pl.length
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end
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#
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# Returns the raw payload that has not had variable substitution occur.
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#
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def payload
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return module_info['Payload'] ? module_info['Payload']['Payload'] : nil
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end
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#
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# Returns the assembly string that describes the payload if one exists.
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#
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def assembly
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return module_info['Payload'] ? module_info['Payload']['Assembly'] : nil
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end
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#
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# Returns the offsets to variables that must be substitute, if any.
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#
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def offsets
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return module_info['Payload'] ? module_info['Payload']['Offsets'] : nil
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end
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#
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# Returns the staging convention that the payload uses, if any. This is
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# used to make sure that only compatible stagers and stages are built
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# (where assumptions are made about register/environment initialization
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# state and hand-off).
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#
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def convention
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module_info['Convention']
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end
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#
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# Returns the module's connection type, such as reverse, bind, noconn,
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# or whatever else the case may be.
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#
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def connection_type
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handler_klass.general_handler_type
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end
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#
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# Returns the method used by the payload to resolve symbols for the purpose
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# of calling functions, such as ws2ord.
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#
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def symbol_lookup
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module_info['SymbolLookup']
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end
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#
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# Checks to see if the supplied convention is compatible with this
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# payload's convention.
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#
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def compatible_convention?(conv)
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# If we ourself don't have a convention or our convention is equal to
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# the one supplied, then we know we are compatible.
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if ((self.convention == nil) or
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(self.convention == conv))
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true
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# On the flip side, if we are a stager and the supplied convention is
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# nil, then we know it's compatible.
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elsif ((payload_type == Type::Stager) and
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(conv == nil))
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true
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# Otherwise, the conventions don't match in some way or another, and as
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# such we deem ourself as not being compatible with the supplied
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# convention.
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else
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false
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end
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end
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#
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# Return the connection associated with this payload, or none if there
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# isn't one.
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#
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def handler_klass
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return module_info['Handler'] || Msf::Handler::None
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end
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#
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# Returns the session class that is associated with this payload and will
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# be used to create a session as necessary.
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#
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def session
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return module_info['Session']
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end
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##
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#
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# Generation & variable substitution
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#
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##
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#
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# Generates the payload and returns the raw buffer to the caller.
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#
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def generate
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internal_generate
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end
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#
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# Substitutes variables with values from the module's datastore in the
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# supplied raw buffer for a given set of named offsets. For instance,
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# RHOST is substituted with the RHOST value from the datastore which will
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# have been populated by the framework.
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#
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# Supprted packing types:
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#
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# - ADDR (foo.com, 1.2.3.4)
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# - ADDR6 (foo.com, fe80::1234:5678:8910:1234)
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# - ADDR16MSB, ADD16LSB, ADDR22MSB, ADD22LSB (foo.com, 1.2.3.4)
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# Advanced packing types for 16/16 and 22/10 bits substitution. The 16
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# bits types uses two offsets indicating where the 16 bits pair will be
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# substituted, while the 22 bits types uses two offsets indicating the
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# instructions where the 22/10 bits pair will be substituted. Normally
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# these are offsets to "sethi" and "or" instructions on SPARC architecture.
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# - HEX (0x12345678, "\x41\x42\x43\x44")
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# - RAW (raw bytes)
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#
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def substitute_vars(raw, offsets)
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offsets.each_pair { |name, info|
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offset, pack = info
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# Give the derived class a chance to substitute this variable
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next if (replace_var(raw, name, offset, pack) == true)
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# Now it's our turn...
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if ((val = datastore[name]))
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if (pack == 'ADDR')
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val = Rex::Socket.resolv_nbo(val)
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# Someone gave us a funky address (ipv6?)
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if(val.length == 16)
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raise RuntimeError, "IPv6 address specified for IPv4 payload."
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end
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elsif (pack == 'ADDR6')
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val = Rex::Socket.resolv_nbo(val)
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# Convert v4 to the v6ish address
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if(val.length == 4)
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nip = "fe80::5efe:" + val.unpack("C*").join(".")
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val = Rex::Socket.resolv_nbo(nip)
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end
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elsif (['ADDR16MSB', 'ADDR16LSB', 'ADDR22MSB', 'ADDR22LSB'].include?(pack))
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val = Rex::Socket.resolv_nbo(val)
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# Someone gave us a funky address (ipv6?)
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if(val.length == 16)
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raise RuntimeError, "IPv6 address specified for IPv4 payload."
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end
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elsif (pack == 'RAW')
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# Just use the raw value...
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else
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# Check to see if the value is a hex string. If so, convert
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# it.
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if val.kind_of?(String)
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if val =~ /^\\x/
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val = [ val.gsub(/\\x/, '') ].pack("H*").unpack(pack)[0]
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elsif val =~ /^0x/
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val = val.hex
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end
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end
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# NOTE:
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# Packing assumes integer format at this point, should fix...
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val = [ val.to_i ].pack(pack)
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end
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# Substitute it
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if (['ADDR16MSB', 'ADDR16LSB'].include?(pack))
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if (offset.length != 2)
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raise RuntimeError, "Missing value for payload offset, there must be two offsets."
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end
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if (pack == 'ADDR16LSB')
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val = val.unpack('N').pack('V')
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end
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raw[offset[0], 2] = val[0, 2]
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raw[offset[1], 2] = val[2, 2]
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elsif (['ADDR22MSB', 'ADDR22LSB'].include?(pack))
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if (offset.length != 2)
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raise RuntimeError, "Missing value for payload offset, there must be two offsets."
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end
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if (pack == 'ADDR22LSB')
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val = val.unpack('N').pack('V')
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end
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hi = (0xfffffc00 & val) >> 10
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lo = 0x3ff & val
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ins = raw[offset[0], 4]
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raw[offset[0], 4] = ins | hi
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ins = raw[offset[1], 4]
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raw[offset[1], 4] = ins | lo
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else
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raw[offset, val.length] = val
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end
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else
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wlog("Missing value for payload offset #{name}, skipping.",
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'core', LEV_3)
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end
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}
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end
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#
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# Replaces an individual variable in the supplied buffer at an offset
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# using the given pack type. This is here to allow derived payloads
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# the opportunity to replace advanced variables.
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#
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def replace_var(raw, name, offset, pack)
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return false
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end
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##
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#
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# Shortcut methods for filtering compatible encoders
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# and NOP sleds
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#
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##
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#
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# Returns the array of compatible encoders for this payload instance.
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#
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def compatible_encoders
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encoders = []
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framework.encoders.each_module_ranked(
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'Arch' => self.arch) { |name, mod|
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encoders << [ name, mod ]
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}
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return encoders
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end
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#
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# Returns the array of compatible nops for this payload instance.
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#
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def compatible_nops
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nops = []
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framework.nops.each_module_ranked(
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'Arch' => self.arch) { |name, mod|
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nops << [ name, mod ]
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}
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return nops
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end
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##
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#
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# Event notifications.
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#
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##
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#
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# Once an exploit completes and a session has been created on behalf of the
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# payload, the framework will call the payload's on_session notification
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# routine to allow it to manipulate the session prior to handing off
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# control to the user.
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#
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def on_session(session)
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# If this payload is associated with an exploit, inform the exploit
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# that a session has been created and potentially shut down any
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# open sockets. This allows active exploits to continue hammering
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# on a service until a session is created.
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if (assoc_exploit)
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# Signal that a new session is created by calling the exploit's
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# on_new_session handler. The default behavior is to set an
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# instance variable, which the exploit will have to check.
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begin
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assoc_exploit.on_new_session(session)
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rescue ::Exception => e
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dlog("#{assoc_exploit.refname}: on_new_session handler triggered exception: #{e.class} #{e} #{e.backtrace}", 'core', LEV_1) rescue nil
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end
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# Set the abort sockets flag only if the exploit is not passive
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# and the connection type is not 'find'
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if (
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(assoc_exploit.exploit_type == Exploit::Type::Remote) and
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(assoc_exploit.passive? == false) and
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(connection_type != 'find')
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)
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assoc_exploit.abort_sockets
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end
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end
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end
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#
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# This attribute holds the string that should be prepended to the buffer
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# when it's generated.
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#
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attr_accessor :prepend
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#
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# This attribute holds the string that should be appended to the buffer
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# when it's generated.
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#
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attr_accessor :append
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#
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# This attribute holds the string that should be prepended to the encoded
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# version of the payload (in front of the encoder as well).
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#
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attr_accessor :prepend_encoder
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#
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# If this payload is associated with an exploit, the assoc_exploit
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# attribute will point to that exploit instance.
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#
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attr_accessor :assoc_exploit
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protected
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#
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# If the payload has assembly that needs to be compiled, do so now.
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# This method takes the raw payload (p), the assembly text (asm), and the
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# offsets hash for variables that need to be substituted (off). The suffix
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# is used to localize the way the generated payload is cached (whether the
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# blob is part of a single, stager, or stage, for example).
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#
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def build(x, asm, off, suffix = '')
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# If there is no assembly to be compiled, then we return a duplicated
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# copy of the raw payload blob
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if(asm.nil? or asm.empty?)
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return x.dup
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end
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cache_key = refname + suffix
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cache_entry = framework.payloads.check_blob_cache(cache_key)
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off.each_pair { |option, val|
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if (val[1] == 'RAW')
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asm = asm.gsub(/#{option}/){ datastore[option] }
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off.delete(option)
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end
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}
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# If there is a valid cache entry, then we don't need to worry about
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# rebuilding the assembly
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if cache_entry
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# Update the local offsets from the cache
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off.each_key { |option|
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off[option] = cache_entry[1][option]
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}
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# Return the cached payload blob
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return cache_entry[0].dup
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end
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# Assemble the payload from the assembly
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sc = Metasm::Shellcode.assemble(Metasm::Ia32.new, asm).encoded
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# Calculate the actual offsets now that it's been built
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off.each_pair { |option, val|
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off[option] = [ sc.offset_of_reloc(option), val[1] ]
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}
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# Cache the payload blob
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framework.payloads.add_blob_cache(cache_key, sc.data, off)
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# Return a duplicated copy of the assembled payload
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sc.data.dup
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end
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|
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#
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# Generate the payload using our local payload blob and offsets
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#
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def internal_generate
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# Build the payload, either by using the raw payload blob defined in the
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# module or by actually assembling it
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raw = build(payload, assembly, offsets, '-stg0')
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# If the payload is generated and there are offsets to substitute,
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# do that now.
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if (raw and offsets)
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substitute_vars(raw, offsets)
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end
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return raw
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end
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|
|
##
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#
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# Custom merge operations for payloads
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#
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##
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#
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# Merge the name to prefix the existing one and separate them
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# with a comma
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#
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def merge_name(info, val)
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if (info['Name'])
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info['Name'] = val + ',' + info['Name']
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else
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info['Name'] = val
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end
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end
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end
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end
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