=begin
Copyright 2009, 2017 Andrew Horton

This file is part of WhatWeb.

WhatWeb is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or at your option) any later version.

WhatWeb is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with WhatWeb.  If not, see <http://www.gnu.org/licenses/>.
=end

module PluginSugar
  def def_field(*names)
    class_eval do
      names.each do |name|
        define_method(name) do |*args|
          if args.empty?
            instance_variable_get("@#{name}")
          else
            instance_variable_set("@#{name}", *args)
          end
        end
      end
    end
  end
end


class Plugin
  extend PluginSugar
  def_field  :author, :version, :description, :website, :matches, :cve, :dorks
  # deprecated fields
  def_field :examples
#, :category
  @registered_plugins = {}

  class << self
    attr_reader :registered_plugins
    private :new
    attr_reader :locked
    attr_reader :plugin_name
    @locked=false
  end

  def self.define(name, &block)
    p = new
    p.set_plugin_name(name)
    p.instance_eval(&block)
    p.startup
    Plugin.registered_plugins[name] = p
  end

  def set_plugin_name(s)
    @plugin_name = s
  end

  def version_detection?
    return false unless @matches
    !@matches.map { |m| m[:version] }.compact.empty?
  end

  # individual plugins can override this
  def startup; end

  # individual plugins can override this
  def shutdown; end

  def lock
    @locked=true
  end

  def unlock
    @locked=false
  end

  def locked?
    @locked
  end

  def init (target)
    @target = target
    @body = target.body
    @headers = target.headers
    @status = target.status
    @base_uri = target.uri
    @md5sum = target.md5sum
    @tagpattern = target.tag_pattern
    @ip = target.ip
    @raw_response = target.raw_response
    @raw_headers = target.raw_headers
  end

  def make_matches(target, match)
    r = []

    # search location
    search_context = target.body # by default
    unless match[:search].nil?
      case match[:search]
      when 'all'
        search_context = target.raw_response
      when 'headers'
        search_context = target.raw_headers
      when /headers\[(.*)\]/
        header = $1.downcase

        if target.headers[header]
          search_context = target.headers[header]
        else
          #error "Invalid search context :search => #{match[:search]}"
          return r
        end
      end
    end

    unless match[:ghdb].nil?
      r << match if match_ghdb(match[:ghdb], target.body, target.headers, target.status, target.uri)
    end

    unless match[:text].nil?
      r << match if match[:regexp_compiled] =~ search_context
    end

    unless match[:md5].nil?
      r << match if target.md5sum == match[:md5]
    end

    unless match[:tagpattern].nil?
      r << match if target.tag_pattern == match[:tagpattern]
    end

    if !match[:regexp_compiled].nil? and !search_context.nil?
      [:regexp, :account, :version, :os, :module, :model, :string, :firmware, :filepath].each do |symbol|
        if match[symbol] and match[symbol].class==Regexp
          regexpmatch = search_context.scan(match[:regexp_compiled])
          unless regexpmatch.empty?
            m = match.dup
            m[symbol] = regexpmatch.map {|eachmatch|
              if eachmatch.is_a?(Array) and match[:offset]
                eachmatch[match[:offset]]
              elsif eachmatch.is_a?(Array)
                eachmatch.first
              elsif eachmatch.is_a?(String)
                eachmatch
              end
            }.flatten.compact.sort.uniq
            r << m
          end
        end
      end
    end

    # all previous matches are OR
    # these are ARE. e.g. required if present
    return r if r.empty?

    # if url and status are present, they must both match
    # url and status cannot be alone. there must be something else that has already matched
    url_matched = false
    status_matched = false

    if match[:status]
      status_matched = true if match[:status] == target.status
    end

    if match[:url]
      # url is not relative if :url starts with /
      # url is relative if :url starts with [^/]
      # url query is only checked if :url has a ?
      # {:url="edit?action=stop" } will only match if the end of the path and the entire query matches.
      # :url is for URIs not regexes

      if match[:url] =~ /^\//
        is_relative = false
      else
        is_relative = true
      end

      if match[:url] =~ /\?/
        has_query = true
      else
        has_query = false
      end

      if is_relative and not has_query
        url_matched = true if target.uri.path =~ /#{match[:url]}$/
      end

      if is_relative and has_query
        if target.uri.query
          url_matched = true if "#{target.uri.path}?#{target.uri.query}" =~ /#{match[:url]}$/
        end
      end

      if not is_relative and has_query
        if target.uri.query
          url_matched = true if "#{target.uri.path}?#{target.uri.query}" == match[:url]
        end
      end

      if not is_relative and not has_query
        url_matched = true if target.uri.path == match[:url]
      end
    end

    # determine whether to return a match
    if match[:status] and match[:url]
      if url_matched and status_matched
        r << match
      else
        r = []
      end
    elsif match[:status] and match[:url].nil?
      if status_matched
        r << match
      else
        r = []
      end
    elsif match[:status].nil? and match[:url]
      if url_matched
        r << match
      else
        r = []
      end
    elsif match[:status].nil? and match[:url].nil?
      # nothing to do
    end

    r
  end

  # execute plugin
  def x
    results = []
    unless @matches.nil?
      @matches.each do |match|
        results += make_matches(@target, match)
      end
    end

    # if the plugin has a passive method, use it
    results += self.passive if defined? self.passive

    # if the plugin has an aggressive method and we're in aggressive mode, use it
    # or if we're guessing all URLs
    if ($AGGRESSION == 3 and !results.empty?) or ($AGGRESSION == 4)
      results += self.aggressive if defined? self.aggressive

      # if any of our matches have a url then fetch it
      # and check the matches[]
      # later we can do some caching

      # we have no caching, so we sort the URLs to fetch and only get 1 unique url per plugin. not great..
      unless @matches.nil?
        lastbase_uri = nil
        thisstatus, thisurl, thisbody, thisheaders = nil # this shouldn't be necessary but ruby thinks its a local variable to the if end statement

        @matches.map { |x| x if x[:url] }.compact.sort_by { |x| x[:url] }.map do |match|
          r = [] # temp results

          newbase_uri = URI.join(@base_uri.to_s, match[:url]).to_s
          aggressivetarget = Target.new(newbase_uri)
          aggressivetarget.open

  #        if $verbose >1
  #          puts "#{@plugin_name} Aggressive: #{aggressivetarget.uri.to_s} [#{aggressivetarget.status}]"
  #        end

          results += make_matches(aggressivetarget, match)
        end
      end
    end
    # clean up results
    unless results.empty?
      results.each do |r|
        r[:certainty] = 100 if r[:certainty].nil?
      end
    end

    results
  end
end


# this class contains stuff related to plugins but not necessary to repeat in each plugin we create
class PluginSupport
  # this is used by load_plugins
  def PluginSupport.load_plugin(f)
    begin
      load f
    rescue => err
      error("Error: failed to load - #{err}")
    rescue SyntaxError => err
      error("Error: Failed to load - #{err}")
    rescue SystemExit, Interrupt
      error("ERROR: Failed to load plugins: Interrupted")
      if $WWDEBUG == true or $verbose > 1
        raise
      end
      exit 1
    end
  end

  # precompile regular expressions in plugins for performance
  def PluginSupport.precompile_regular_expressions
    Plugin.registered_plugins.each do |thisplugin|
      matches = thisplugin[1].matches
      unless matches.nil?
        matches.each do |thismatch|
          unless thismatch[:regexp].nil?
            #pp thismatch
            thismatch[:regexp_compiled]=Regexp.new(thismatch[:regexp])
          end

          [:version, :os, :string, :account, :model, :firmware, :module, :filepath].each do |label|
            if !thismatch[label].nil? and thismatch[label].class == Regexp
              thismatch[:regexp_compiled] = Regexp.new(thismatch[label])
              #pp thismatch
            end
          end

          unless thismatch[:text].nil?
            thismatch[:regexp_compiled] = Regexp.new(Regexp.escape(thismatch[:text]))
          end
        end
      end
    end
  end

=begin
for adding/removing sets of plugins.

--plugins +plugins-disabled,-foobar (+ adds to the full set, -removes from the fullset. items can be directories, files or plugin names)
--plugins +/tmp/moo.rb
--plugins foobar (only select foobar)
--plugins ./plugins-disabled,-md5 (select only plugins from the plugins-disabled folder, remove the md5 plugin from the selected list)

does not work correctly with mixed plugin names and files

=end
  def PluginSupport.load_plugins(list = nil)
    # separate list into a and b
    #  a = make list of dir & filenames
    #  b = make list of assumed pluginnames

    a = []
    b = []

    plugin_dirs = PLUGIN_DIRS.clone
    plugin_dirs.map { |p| p = File.expand_path(p) }

    if list
      list = list.split(",")

      plugins_disabled_location = ["plugins-disabled"].map do |x|
        $LOAD_PATH.map do |y|
          path = "#{y}/#{x}"
          path if File.exists?(path)
        end
      end.flatten.compact.first

      list.each { |x| x.gsub!(/^\+$/, "+#{plugins_disabled_location}") } # + is short for +plugins-disabled

      list.each do |p|
        choice = PluginChoice.new
        choice.fill(p)
        a << choice if choice.type == "file"
        b << choice if choice.type == "plugin"
      end

      #puts "a: list of dir + filenames"
      #pp a
      #puts "b: list of plugin names"
      #pp b
      #puts "Plugin Dirs"
      #pp plugin_dirs

      # sort by neither, add, minus
      a = a.sort

      # plugin_dirs gets wiped out if no modifier is used on a file/folder
      if a.map { |c| c.modifier }.include?(nil)
        plugin_dirs = []
      end

      minus_files = [] # make list of files not to load
      a.map { |c|
        plugin_dirs << c.name if c.modifier.nil? or c.modifier == "+"
        plugin_dirs -= [c.name] if c.modifier == "-" # for Dirs
        minus_files << c.name if c.modifier == "-"    # for files
      }

      #puts "Plugin Dirs"
        #pp plugin_dirs

      #puts "before plugin_dirs.each "
      #pp Plugin.registered_plugins.size

      # load files from plugin_dirs unless a file is minused
      plugin_dirs.each do |d|
        # if a folder, then load all files
        if File.directory?(d)
          (Dir.glob("#{d}/*.rb") - minus_files).each { |x| PluginSupport.load_plugin(x) }
        elsif File.exists?(d)
          PluginSupport.load_plugin(d)
        else
          error("Error: #{d} is not Dir or File")
        end
      end

      #puts "after plugin_dirs.each "
      #pp Plugin.registered_plugins.size

      # make list of plugins to run
      # go through all plugins, remove from list any that match b minus
      selected_plugin_names = []

      if b.map {|c| c.modifier }.include?(nil)
        selected_plugin_names = []
      else
        selected_plugin_names = Plugin.registered_plugins.map { |n, p| n.downcase }
      end

      b.map {|c|
        selected_plugin_names << c.name if c.modifier.nil? or c.modifier == "+"
        selected_plugin_names -= [c.name] if c.modifier == "-"
      }

      #pp selected_plugin_names
      # Plugin.registered_plugins is getting wiped out

      plugins_to_use = Plugin.registered_plugins.map do |n, p|
        [n, p] if selected_plugin_names.include?(n.downcase)
      end.compact
      #puts "after "

      # report on plugins that couldn't be found
      unfound_plugins = selected_plugin_names - plugins_to_use.map { |n, p| n.downcase }
      unless unfound_plugins.empty?
        puts "Error: The following plugins were not found: " + unfound_plugins.join(",")
      end

    else
      # no selection, so it's default
      plugin_dirs.each do |d|
        Dir.glob("#{d}/*.rb").each { |x| PluginSupport.load_plugin(x) }
      end
      plugins_to_use = Plugin.registered_plugins
    end

    #puts "-" * 80
    #pp plugins_to_use

    plugins_to_use
  end

  def PluginSupport.custom_plugin(c, *option)
    if option == ["grep"]
      matches = "matches [:text=>\"#{c}\"]"

      custom = "# coding: ascii-8bit
      Plugin.define \"Grep\" do
      author \"Unknown\"
      description \"User defined\"
      website \"User defined\"
      #{matches}
      end
      "
    else
      # define a custom plugin on the cmdline
      # ":text=>'powered by abc'" or
      # "{:text=>'powered by abc'},{:regexp=>/abc [ ]?1/i}"

      # then it's ok..
      if c =~ /:(text|ghdb|md5|regexp|tagpattern)=>[\/'"].*/
        matches="matches [\{#{c}\}]"
      end

      # this isn't checked for sanity... loading plugins = cmd exec anyway
      if c =~ /\{.*\}/
        matches = "matches [#{c}]"
      end

      abort("Invalid custom plugin syntax: #{c}") if matches.nil?

      custom = "# coding: ascii-8bit
      Plugin.define \"Custom-Plugin\" do
      author \"Unknown\"
      description \"User defined\"
      website \"User defined\"
      #{matches}
      end
      "
    end

    begin
      # open tmp file
      f = Tempfile.new('whatweb-custom-plugin')
      # write
      f.write(custom)
      f.close
      pp custom if $verbose > 2
      # load
      load f.path
      f.unlink
      true
    rescue SyntaxError
      error("Error: Cannot load custom plugin")
      false
    end
  end

  ### some UI stuff
  def PluginSupport.plugin_list
    terminal_width = 80
    puts "WhatWeb Plugin List"
    puts
    puts "Plugin Name - Description"
    puts "-" * terminal_width
    Plugin.registered_plugins.sort_by { |a, b| a.downcase }.each do |n, p|
      # output fits more description onto a line
      line = "#{n} - "
      line += p.description.delete("\r\n") if p.description

      if line.size > terminal_width - 1
        line = line[0..terminal_width - 4] + "..."
      end
      puts line
    end
    puts "-" * terminal_width
    puts
    puts "Total: #{Plugin.registered_plugins.size} Plugins"
    puts
    puts "Hint:"
    puts "For complete plugin descriptions use : whatweb --info-plugins <SEARCH>"
    puts "Use it without a search term for a complete description of all plugins."
    puts
  end

  # Show Google Dorks
  def PluginSupport.plugin_dorks(plugin_name)
    dorks = []

    # Loop through plugins
    Plugin.registered_plugins.each do |n, p|
      if n.downcase == plugin_name.downcase
        pp "Google Dorks for #{n}:" if $verbose > 2
        dorks << p.dorks unless p.dorks.nil?
      end
    end

    # Show results if present, else show error message
    if dorks.size > 0
      puts dorks
    else
      error("Google dork lookup failed: Invalid plugin name or no dorks available")
    end
  end

  # Show plugin information
  def PluginSupport.plugin_info(keywords = nil)
    terminal_width = 80

    puts "WhatWeb Detailed Plugin List"
    puts "Searching for " + keywords.join(",") unless keywords.empty?

    count = {plugins: 0, version_detection: 0, matches: 0, dorks: 0, aggressive: 0, passive: 0 }

    Plugin.registered_plugins.sort_by { |a, b| a.downcase }.each do |name, plugin|
      dump = [name, plugin.author, plugin.description, plugin.website, plugin.matches].flatten.compact.to_a.join.downcase

      # this will fail is an expected variable is not defined or empty
      if keywords.empty? or keywords.map { |k| dump.include?(k.downcase) }.compact.include?(true)
        puts "=" * terminal_width
        puts "Plugin:".ljust(16) + name
        puts "-" * terminal_width

        if plugin.description
          word_wrap(plugin.description, terminal_width - 16).each_with_index do |line, index|
            if index == 0
              print "Description:".ljust(16)
            else
              print " " * 16
            end
            puts line
          end
        else
          print "Description:".ljust(16) + "<Not defined>"
        end

        puts "Website:".ljust(16) + (plugin.website || "<Not defined>")
        puts
        puts "Author:".ljust(16) + (plugin.author || "<Not defined>")
        puts "Version:".ljust(16) + (plugin.version || "<Not defined>")
        puts
        print "Features:".ljust(16)
        print "[#{defined?(plugin.matches) and plugin.matches ? "Yes" : "No"}]".ljust(7) + "Pattern Matching"

        if defined?(plugin.matches) and plugin.matches
          puts " (#{plugin.matches.size})"
        else
          puts
        end

        puts " " * 16 + "[#{plugin.version_detection? ? "Yes" : "No" }]".ljust(7) + "Version detection from pattern matching"
        puts " " * 16 + "[#{defined?(plugin.passive) ? "Yes" : "No"}]".ljust(7) + "Function for passive matches"
        puts " " * 16 + "[#{defined?(plugin.aggressive) ? "Yes" : "No"}]".ljust(7) + "Function for aggressive matches"

        count[:version_detection] += 1 if plugin.version_detection?
        count[:passive] += 1 if defined?(plugin.passive)
        count[:aggressive] += 1 if defined?(plugin.aggressive)

        print " " * 16 + "[#{plugin.dorks ? "Yes" : "No"}]".ljust(7) + "Google Dorks"
        if plugin.dorks
          puts " (#{plugin.dorks.size})"
        else
          puts
        end

        puts

        if plugin.dorks
          puts "Google Dorks:"
          plugin.dorks.each_with_index do |dork, index|
            puts "[#{index + 1 }] #{dork}"
          end
          puts
          count[:dorks] += plugin.dorks.size
        end

        if defined?(plugin.matches) and plugin.matches
          #puts "Pattern Matching:"
          #plugin.matches.each_with_index do |match, index|
          #  puts "[#{index + 1 }] #{match}"
          #end
          #puts
          count[:matches] += plugin.matches.size
        end

        count[:plugins] += 1
      end
    end

    puts "=" * terminal_width
    puts "Total plugins: #{count[:plugins]}"
    puts "Total plugins with version detection from pattern matching: #{count[:version_detection]}"
    puts "Total patterns (regular expressions, text, MD5 hashes, etc): #{count[:matches]}"
    puts "Total Google dorks: #{count[:dorks]}"
    puts "Total aggressive functions: #{count[:aggressive]}"
    puts "Total passive functions: #{count[:passive]}"
    puts
  end
end


# This is used in plugin selection by load_plugins
class PluginChoice
  attr_accessor :modifier, :type, :name

  def <=>(s)
    x = -1 if self.modifier.nil?
    x = 0 if self.modifier == "+"
    x = 1 if self.modifier == "-"
    x
  end

  def fill(s)
    self.modifier = nil
    self.modifier = s[0].chr if ["+", "-"].include?(s[0].chr)

    if self.modifier
      self.name = s[1..-1]
    else
      self.name = s
    end

    # figure out and store the filename or pluginname
    if File.exists?(File.expand_path(self.name))
      self.type = "file"
      self.name = File.expand_path(self.name)
    else
      self.name.downcase!
      self.type = "plugin"
    end
  end
end