# Copyright (c) 2015-2021 Vector 35 Inc
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.


# This plugin assumes angr is already installed and available on the system. See the angr documentation
# for information about installing angr. It should be installed using the virtualenv method.
#
# This plugin is currently only known to work on Linux using virtualenv. Switch to the virtual environment
# (using a command such as "workon angr"), then run the Binary Ninja UI from the command line.
#
# This method is known to fail on Mac OS X as the virtualenv used by angr does not appear to provide a
# way to automatically link to the correct version of Python, even when running the UI from within the
# virtual environment. A later update may allow for a manual override to link to the required version
# of Python.

import tempfile
import logging
import os

__name__ = "__console__"  # angr looks for this, it won't load from within a UI without it

import angr
# For the lazy instead you can just import everything 'from binaryninja import *''
from binaryninja.binaryview import BinaryView
from binaryninja.plugin import BackgroundTaskThread, PluginCommand
from binaryninja.interaction import show_plain_text_report, show_message_box
from binaryninja.highlight import HighlightColor
from binaryninja.enums import HighlightStandardColor, MessageBoxButtonSet, MessageBoxIcon

# Disable warning logs as they show up as errors in the UI
logging.disable(logging.WARNING)

# Create sets in the BinaryView's data field to store the desired path for each view
BinaryView.set_default_session_data("angr_find", set())
BinaryView.set_default_session_data("angr_avoid", set())


def escaped_output(str):
	return '\n'.join([s.encode("string_escape") for s in str.split('\n')])


# Define a background thread object for solving in the background
class Solver(BackgroundTaskThread):
	def __init__(self, find, avoid, view):
		BackgroundTaskThread.__init__(self, "Solving with angr...", True)
		self.find = tuple(find)
		self.avoid = tuple(avoid)
		self.view = view

		# Write the binary to disk so that the angr API can read it
		self.binary = tempfile.NamedTemporaryFile()
		self.binary.write(view.file.raw.read(0, len(view.file.raw)))
		self.binary.flush()

	def run(self):
		# Create an angr project and an explorer with the user's settings
		p = angr.Project(self.binary.name)
		e = p.surveyors.Explorer(find = self.find, avoid = self.avoid)

		# Solve loop
		while not e.done:
			if self.cancelled:
				# Solve cancelled, show results if there were any
				if len(e.found) > 0:
					break
				return

			# Perform the next step in the solve
			e.step()

			# Update status
			active_count = len(e.active)
			found_count = len(e.found)

			progress = "Solving with angr (%d active path%s" % (active_count, "s" if active_count != 1 else "")
			if found_count > 0:
				progress += ", %d path%s found" % (found_count, "s" if found_count != 1 else "")
			self.progress = progress + ")..."

		# Solve complete, show report
		text_report = "Found %d path%s.\n\n" % (len(e.found), "s" if len(e.found) != 1 else "")
		i = 1
		for f in e.found:
			text_report += "Path %d\n" % i + "=" * 10 + "\n"
			text_report += "stdin:\n" + escaped_output(f.state.posix.dumps(0)) + "\n\n"
			text_report += "stdout:\n" + escaped_output(f.state.posix.dumps(1)) + "\n\n"
			text_report += "stderr:\n" + escaped_output(f.state.posix.dumps(2)) + "\n\n"
			i += 1

		name = self.view.file.filename
		if len(name) > 0:
			show_plain_text_report("Results from angr - " + os.path.basename(self.view.file.filename), text_report)
		else:
			show_plain_text_report("Results from angr", text_report)


def find_instr(bv, addr):
	# Highlight the instruction in green
	blocks = bv.get_basic_blocks_at(addr)
	for block in blocks:
		block.set_auto_highlight(HighlightColor(HighlightStandardColor.GreenHighlightColor, alpha = 128))
		block.function.set_auto_instr_highlight(addr, HighlightStandardColor.GreenHighlightColor)

	# Add the instruction to the list associated with the current view
	bv.session_data.angr_find.add(addr)


def avoid_instr(bv, addr):
	# Highlight the instruction in red
	blocks = bv.get_basic_blocks_at(addr)
	for block in blocks:
		block.set_auto_highlight(HighlightColor(HighlightStandardColor.RedHighlightColor, alpha = 128))
		block.function.set_auto_instr_highlight(addr, HighlightStandardColor.RedHighlightColor)

	# Add the instruction to the list associated with the current view
	bv.session_data.angr_avoid.add(addr)


def solve(bv):
	if len(bv.session_data.angr_find) == 0:
		show_message_box("Angr Solve", "You have not specified a goal instruction.\n\n" +
			"Please right click on the goal instruction and select \"Find Path to This Instruction\" to " +
			"continue.", MessageBoxButtonSet.OKButtonSet, MessageBoxIcon.ErrorIcon)
		return

	# Start a solver thread for the path associated with the view
	s = Solver(bv.session_data.angr_find, bv.session_data.angr_avoid, bv)
	s.start()


# Register commands for the user to interact with the plugin
PluginCommand.register_for_address("Find Path to This Instruction",
	"When solving, find a path that gets to this instruction", find_instr)
PluginCommand.register_for_address("Avoid This Instruction",
	"When solving, avoid paths that reach this instruction", avoid_instr)
PluginCommand.register("Solve With Angr", "Attempt to solve for a path that satisfies the constraints given", solve)
