metasploit-framework/lib/rex/proto/http/request.rb

# -*- coding: binary -*-
require 'uri'
require 'rex/proto/http'

module Rex
module Proto
module Http

###
#
# HTTP request class.
#
###
class Request < Packet

	PostRequests = ['POST', 'SEARCH']

	##
	#
	# Some individual request types.
	#
	##

	#
	# HTTP GET request class wrapper.
	#
	class Get < Request
		def initialize(uri = '/', proto = DefaultProtocol)
			super('GET', uri, proto)
		end
	end

	#
	# HTTP POST request class wrapper.
	#
	class Post < Request
		def initialize(uri = '/', proto = DefaultProtocol)
			super('POST', uri, proto)
		end
	end

	#
	# HTTP PUT request class wrapper.
	#
	class Put < Request
		def initialize(uri = '/', proto = DefaultProtocol)
			super('PUT', uri, proto)
		end
	end

	#
	# Initializes an instance of an HTTP request with the supplied method, URI,
	# and protocol.
	#
	def initialize(method = 'GET', uri = '/', proto = DefaultProtocol)
		super()

		self.method    = method
		self.raw_uri   = uri
		self.uri_parts = {}
		self.proto     = proto || DefaultProtocol
		self.chunk_min_size = 1
		self.chunk_max_size = 10
		self.uri_encode_mode = 'hex-normal'

		update_uri_parts
	end

	#
	# Updates the command parts for this specific packet type.
	#
	def update_cmd_parts(str)
		if (md = str.match(/^(.+?)\s+(.+?)\s+HTTP\/(.+?)\r?\n?$/))
			self.method  = md[1]
			self.raw_uri = URI.decode(md[2])
			self.proto   = md[3]

			update_uri_parts
		else
			raise RuntimeError, "Invalid request command string", caller
		end
	end

	#
	# Split the URI into the resource being requested and its query string.
	#
	def update_uri_parts
		# If it has a query string, get the parts.
		if ((self.raw_uri) and (md = self.raw_uri.match(/(.+?)\?(.*)$/)))
			self.uri_parts['QueryString'] = parse_cgi_qstring(md[2])
			self.uri_parts['Resource']    = md[1]
		# Otherwise, just assume that the URI is equal to the resource being
		# requested.
		else
			self.uri_parts['QueryString'] = {}
			self.uri_parts['Resource']    = self.raw_uri
		end

		self.normalize!(resource)
		# Set the relative resource to the actual resource.
		self.relative_resource = resource
	end

	# normalize out multiple slashes, directory traversal, and self referrential directories
	def normalize!(str)
		i = 0
		while (str.gsub!(/(\/\.\/|\/\w+\/\.\.\/|\/\/)/,'/')); i += 1; end
		i
	end

	# Puts a URI back together based on the URI parts
	def uri
		str = self.uri_parts['Resource'].dup || '/'

		# /././././
		if self.junk_self_referring_directories
			str.gsub!(/\//) {
				'/.' * (rand(3) + 1) + '/'
			}
		end

		# /%3faaa=bbbbb
		# which could possibly decode to "/?aaa=bbbbb", which if the IDS normalizes first, then splits the URI on ?, then it can be bypassed
		if self.junk_param_start
			str.sub!(/\//, '/%3f' + Rex::Text.rand_text_alpha(rand(5) + 1) + '=' + Rex::Text.rand_text_alpha(rand(10) + 1) + '/../')
		end

		# /RAND/../RAND../
		if self.junk_directories
			str.gsub!(/\//) {
				dirs = ''
				(rand(5)+5).times {
					dirs << '/' + Rex::Text.rand_text_alpha(rand(5) + 1) + '/..'
				}
				dirs + '/'
			}
		end

		# ////
		#
		# NOTE: this must be done after all other odd directory junk, since they would cancel this out, except junk_end_of_uri, since that a specific slash in a specific place
		if self.junk_slashes
			str.gsub!(/\//) {
				'/' * (rand(3) + 2)
			}
			str.sub!(/^[\/]+/, '/') # only one beginning slash!
		end

		# /%20HTTP/1.0%0d%0a/../../
		# which decodes to "/ HTTP/1.0\r\n"
		if self.junk_end_of_uri
			str.sub!(/^\//, '/%20HTTP/1.0%0d%0a/../../')
		end

		Rex::Text.uri_encode(str, self.uri_encode_mode)

		if !PostRequests.include?(self.method)
			if param_string.size > 0
				str << '?' + param_string
			end
		end
		str
	end

	def param_string
		params=[]
		self.uri_parts['QueryString'].each_pair { |param, value|
			# inject a random number of params in between each param
			if self.junk_params
				rand(10)+5.times {
					params.push(Rex::Text.rand_text_alpha(rand(16) + 5) + '=' + Rex::Text.rand_text_alpha(rand(10) + 1))
				}
			end
			if value.kind_of?(Array)
				value.each { |subvalue|
    				params.push(Rex::Text.uri_encode(param, self.uri_encode_mode) + '=' + Rex::Text.uri_encode(subvalue, self.uri_encode_mode))
				}
			else
				if !value.nil?
					params.push(Rex::Text.uri_encode(param, self.uri_encode_mode) + '=' + Rex::Text.uri_encode(value, self.uri_encode_mode))
				else
					params.push(Rex::Text.uri_encode(param, self.uri_encode_mode))
				end
			end
		}

		# inject some junk params at the end of the param list, just to be sure :P
		if self.junk_params
			rand(10)+5.times {
				params.push(Rex::Text.rand_text_alpha(rand(32) + 5) + '=' + Rex::Text.rand_text_alpha(rand(64) + 5))
			}
		end
		params.join('&')
	end

	# Updates the underlying URI structure
	def uri=(str)
		self.raw_uri = str
		update_uri_parts
	end

	# Returns a request packet
	def to_s
		str = ''
		if self.junk_pipeline
			host = ''
			if self.headers['Host']
				host = "Host: #{self.headers['Host']}\r\n"
			end
			str << "GET / HTTP/1.1\r\n#{host}Connection: Keep-Alive\r\n\r\n" * self.junk_pipeline
			self.headers['Connection'] = 'Closed'
		end
		str + super
	end

	def body
		str = super || ''
		if str.length > 0
			return str
		end

		if PostRequests.include?(self.method)
			return param_string
		end
		''
	end

	#
	# Returns the command string derived from the three values.
	#
	def cmd_string
		proto_str = (self.proto =~ /^\d/) ? "HTTP/#{self.proto}" : self.proto

		"#{self.method} #{self.uri} #{proto_str}\r\n"
	end

	#
	# Returns the resource that is being requested.
	#
	def resource
		self.uri_parts['Resource']
	end

	#
	# Changes the resource URI.  This is used when making a request relative to
	# a given mount point.
	#
	def resource=(rsrc)
		self.uri_parts['Resource'] = rsrc
	end

	#
	# If there were CGI parameters in the URI, this will hold a hash of each
	# variable to value.  If there is more than one value for a given variable,
	# an array of each value is returned.
	#
	def qstring
		self.uri_parts['QueryString']
	end

	#
	# Returns a hash of variables that contain information about the request,
	# such as the remote host information.
	#
	# TODO
	#
	def meta_vars
	end

	#
	# The method being used for the request (e.g. GET).
	#
	attr_accessor :method
	#
	# The raw URI being requested, before any mucking gets to it
	#
	attr_accessor :raw_uri

	#
	# The split up parts of the URI.
	#
	attr_accessor :uri_parts
	#
	# The protocol to be sent with the request.
	#
	attr_accessor :proto

	#
	# The resource path relative to the root of a server mount point.
	#
	attr_accessor :relative_resource

	# add junk directories
	attr_accessor :junk_directories

	# add junk slashes
	attr_accessor :junk_slashes

	# add junk self referring directories (aka  /././././)
	attr_accessor :junk_self_referring_directories

	# add junk params
	attr_accessor :junk_params

	# add junk pipeline requests
	attr_accessor :junk_pipeline

	# add junk start of params
	attr_accessor :junk_param_start

	# add junk end of URI
	attr_accessor :junk_end_of_uri

	# encoding uri
	attr_accessor :uri_encode_mode

	#
	# Parses a CGI query string into the var/val combinations.
	#
	def parse_cgi_qstring(str)
		qstring = {}

		# Delimit on each variable
		str.split(/[;&]/).each { |vv|
			var = vv
			val = ''

			if (md = vv.match(/(.+?)=(.*)/))
				var = md[1]
				val = md[2]
			end

			# Add the item to the hash with logic to convert values to an array
			# if so desired.
			if (qstring.include?(var))
				if (qstring[var].kind_of?(Array))
					qstring[var] << val
				else
					curr = self.qstring[var]
					qstring[var] = [ curr, val ]
				end
			else
				qstring[var] = val
			end
		}

		return qstring
	end

end

end
end
end