metasploit-framework/lib/rex/ropbuilder/rop.rb

270 lines
6.0 KiB
Ruby

require 'metasm'
require 'rex/compat'
require 'rex/ui/text/table'
require 'rex/ui/text/output/stdio'
require 'rex/ui/text/color'
module Rex
module RopBuilder
class RopBase
def initialize()
@stdio = Rex::Ui::Text::Output::Stdio.new
@gadgets = []
end
def to_csv(gadgets = [])
if gadgets.empty? and @gadgets.nil? or @gadgets.empty?
@stdio.print_error("No gadgets collected to convert to CSV format.")
return
end
# allow the users to import gadget collections from multiple files
if @gadgets.empty? or @gadgets.nil?
@gadgets = gadgets
end
table = Rex::Ui::Text::Table.new(
'Header' => "#{@file} ROP Gadgets",
'Indent' => 1,
'Columns' =>
[
"Address",
"Raw",
"Disassembly",
])
@gadgets.each do |gadget|
table << [gadget[:address], gadget[:raw].unpack('H*')[0], gadget[:disasm].gsub(/\n/, ' | ')]
end
return table.to_csv
end
def import(file)
begin
data = File.new(file, 'r').read
rescue
@stdio.print_error("Error reading #{file}")
return []
end
if data.empty? or data.nil?
return []
end
data.gsub!(/\"/, '')
data.gsub!("Address,Raw,Disassembly\n", '')
@gadgets = []
data.each_line do |line|
addr, raw, disasm = line.split(',', 3)
if addr.nil? or raw.nil? or disasm.nil?
@stdio.print_error("Import file format corrupted")
return []
end
disasm.gsub!(/: /, ":\t")
disasm.gsub!(' | ', "\n")
raw = [raw].pack('H*')
@gadgets << {:file => file, :address => addr, :raw => raw, :disasm => disasm.chomp!}
end
@gadgets
end
def print_msg(msg, color=true)
if not @stdio
@stdio = Rex::Ui::Text::Output::Stdio.new
end
if color == true
@stdio.auto_color
else
@stdio.disable_color
end
@stdio.print_raw(@stdio.substitute_colors(msg))
end
end
class RopCollect < RopBase
def initialize(file="")
@stdio = Rex::Ui::Text::Output::Stdio.new
@file = file if not file.empty?
@bin = Metasm::AutoExe.decode_file(file) if not file.empty?
@disassembler = @bin.disassembler if not @bin.nil?
if @disassembler
@disassembler.cpu = Metasm::Ia32.new('386_common')
end
super()
end
def collect(depth, pattern)
matches = []
gadgets = []
# find matches by scanning for the pattern
matches = @disassembler.pattern_scan(pattern)
if @bin.kind_of?(Metasm::PE)
@bin.sections.each do |section|
next if section.characteristics.include? 'MEM_EXECUTE'
# delete matches if the address is outside the virtual address space
matches.delete_if do |ea|
va = section.virtaddr + @bin.optheader.image_base
ea >= va and ea < va + section.virtsize
end
end
elsif @bin.kind_of?(Metasm::ELF)
@bin.segments.each do |seg|
next if seg.flags.include? 'X'
matches.delete_if do |ea|
ea >= seg.vaddr and ea < seg.vaddr + seg.memsz
end
end
elsif @bin.kind_of?(Metasm::MachO)
@bin.segments.each do |seg|
next if seg.initprot.include? 'EXECUTE'
matches.delete_if do |ea|
ea >= seg.virtaddr and ea < seg.virtaddr + seg.filesize
end
end
end
gadgets = process_gadgets(matches, depth)
gadgets.each do |gadget|
@gadgets << gadget
end
gadgets
end
def pattern_search(pattern)
p = Regexp.new("(" + pattern + ")")
matches = []
@gadgets.each do |gadget|
disasm = ""
addrs = []
gadget[:disasm].each_line do |line|
addr, asm = line.split("\t", 2)
addrs << addr
disasm << asm
end
if gadget[:raw] =~ p or gadget[:disasm] =~ p or disasm =~ p
matches << {:gadget => gadget, :disasm => disasm, :addrs => addrs}
end
end
matches.each do |match|
@stdio.print_status("gadget with address: %bld%cya#{match[:gadget][:address]}%clr matched")
color_pattern(match[:gadget], match[:disasm], match[:addrs], p)
end
matches
end
def color_pattern(gadget, disasm, addrs, p)
idx = disasm.index(p)
if idx.nil?
print_msg(gadget[:disasm])
return
end
disasm = disasm.insert(idx, "%bld%grn")
asm = ""
cnt = 0
colors = false
disasm.each_line do |line|
# if we find this then we are in the matching area
if line.index(/\%bld\%grn/)
colors = true
end
asm << "%clr" + addrs[cnt] + "\t"
# color the remaining parts of the gadget
if colors and line.index("%bld%grn").nil?
asm << "%bld%grn" + line
else
asm << line
end
cnt += 1
end
asm << "%clr\n"
print_msg(asm)
end
def process_gadgets(rets, num)
ret = {}
gadgets = []
tmp = []
rets.each do |ea|
insn = @disassembler.disassemble_instruction(ea)
next if not insn
xtra = insn.bin_length
1.upto(num) do |x|
addr = ea - x
# get the disassembled instruction at this address
di = @disassembler.disassemble_instruction(addr)
# skip invalid instructions
next if not di
next if di.opcode.props[:setip]
next if di.opcode.props[:stopexec]
# get raw bytes
buf = @disassembler.read_raw_data(addr, x + xtra)
# make sure disassembling forward leads to our instruction
next if not ends_with_addr(buf, addr, ea)
dasm = ""
while addr <= ea
di = @disassembler.disassemble_instruction(addr)
dasm << ("0x%08x:\t" % addr) + di.instruction.to_s + "\n"
addr = addr + di.bin_length
end
if not tmp.include?(ea)
tmp << ea
else
next
end
# otherwise, we create a new tailchunk and add it to the list
ret = {:file => @file, :address => ("0x%08x" % (ea - x)), :raw => buf, :disasm => dasm}
gadgets << ret
end
end
gadgets
end
private
def ends_with_addr(raw, base, addr)
dasm2 = Metasm::Shellcode.decode(raw, @disassembler.cpu).disassembler
offset = 0
while ((di = dasm2.disassemble_instruction(offset)))
return true if (base + offset) == addr
return false if di.opcode.props[:setip]
return false if di.opcode.props[:stopexec]
offset = di.next_addr
end
false
end
def raw_instructions(raw)
insns = []
d2 = Metasm::Shellcode.decode(raw, @disassembler.cpu).disassembler
addr = 0
while ((di = d2.disassemble_instruction(addr)))
insns << di.instruction
addr = di.next_addr
end
insns
end
end
end
end