Module: PWN::Plugins::MitmProxy

Defined in:
lib/pwn/plugins/mitm_proxy.rb

Overview

Native HTTP interception and opaque CONNECT tunnelling. CONNECT traffic is not decrypted: HAR explicitly marks the tunnel as metadata-only.

Defined Under Namespace

Classes: Server

Constant Summary collapse

SESSIONS =

rubocop:disable Style/MutableConstant -- live process-local session registry

{}
LOCK = 
Mutex.new
HOP_HEADERS = 
%w[connection keep-alive proxy-authenticate proxy-authorization proxy-connection te trailer trailers transfer-encoding upgrade content-length host].freeze

Class Method Summary collapse

Class Method Details

.authors ⇒ Object 



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# File 'lib/pwn/plugins/mitm_proxy.rb', line 260

public_class_method def self.authors
  "AUTHOR(S):\n  0day Inc. <[email protected]>\n"
end

.entries(opts = {}) ⇒ Object 



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# File 'lib/pwn/plugins/mitm_proxy.rb', line 90

public_class_method def self.entries(opts = {})
  session = lookup(opts)
  session[:mutex].synchronize { Marshal.load(Marshal.dump(session[:entries])) }
end

.exchange(opts = {}) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/pwn/plugins/mitm_proxy.rb', line 124

public_class_method def self.exchange(opts = {})
  session = lookup(opts)
  request = Marshal.load(Marshal.dump(opts.fetch(:request)))
  session[:on_request]&.call(request)
  apply_rules(proxy: session, phase: 'request', message: request)
  uri = URI(request[:url])
  raise ArgumentError, 'HTTP(S) URL without userinfo required' unless %w[http https].include?(uri.scheme) && uri.host && !uri.userinfo

  method = request[:method].to_s.upcase
  raise ArgumentError, 'invalid HTTP method' unless method.match?(/\A[A-Z]+\z/) && method != 'CONNECT'

  headers = clean_headers(headers: request[:headers])
  headers['accept-encoding'] ||= 'identity'
  client = Net::HTTP.new(uri.host, uri.port, nil) # Never inherit ambient proxies.
  client.use_ssl = uri.scheme == 'https'
  client.open_timeout = client.read_timeout = client.write_timeout = session[:timeout]
  wire = Net::HTTPGenericRequest.new(method, !request[:body].to_s.empty?, method != 'HEAD', uri.request_uri, headers)
  wire.body = request[:body].to_s unless request[:body].to_s.empty?
  started = Time.now.utc
  clock = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  response = client.request(wire)
  message = { headers: response.to_hash.transform_values { |v| v.join(', ') }, body: response.body.to_s }
  session[:on_response]&.call(message)
  apply_rules(proxy: session, phase: 'response', message: message)
  elapsed = (Process.clock_gettime(Process::CLOCK_MONOTONIC) - clock) * 1000
  response_headers = clean_headers(headers: message[:headers]).map { |k, v| { name: k, value: v } }
  response_headers.reject! { |h| h[:name] == 'set-cookie' }
  Array(response.get_fields('set-cookie')).each { |v| response_headers << { name: 'set-cookie', value: v } }
  entry = { _request_id: SecureRandom.hex(12), startedDateTime: started.iso8601(6), time: elapsed,
            request: { method: method, url: uri.to_s, httpVersion: 'HTTP/1.1', headers: headers.map { |k, v| { name: k, value: v } },
                       queryString: URI.decode_www_form(uri.query.to_s).map { |k, v| { name: k, value: v } }, cookies: [],
                       headersSize: -1, bodySize: request[:body].to_s.bytesize,
                       postData: encoded(body: request[:body].to_s).merge(mimeType: headers['content-type'].to_s) },
            response: { status: response.code.to_i, statusText: response.message, httpVersion: 'HTTP/1.1',
                        headers: response_headers, cookies: [], redirectURL: response['location'].to_s, headersSize: -1,
                        bodySize: message[:body].bytesize, content: encoded(body: message[:body]).merge(size: message[:body].bytesize, mimeType: response['content-type'].to_s) },
            cache: {}, timings: { send: 0, wait: elapsed, receive: 0 } }
  persist_entry(proxy: session, entry: entry)
  entry
end

.help ⇒ Object 



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# File 'lib/pwn/plugins/mitm_proxy.rb', line 264

public_class_method def self.help
  puts "USAGE:
    # Start a native HTTP capture proxy; CONNECT tunnels are metadata-only.
    #{self}.start(
      har_path: 'optional - HAR destination, contains sensitive raw traffic',
      host: 'optional - bind address, default 127.0.0.1',
      port: 'optional - bind port, default ephemeral',
      backend: 'optional - native (only supported backend)',
      rules: 'optional - literal phase/field/match/replace rules',
      timeout: 'optional - upstream timeout seconds, default 30',
      on_request: 'optional - callable that mutates the request hash',
      on_response: 'optional - callable that mutates the response hash',
      mitm_tls: 'optional - true generates a local CA for TLS interception'
    )

    # Return a snapshot of captured HAR entries.
    #{self}.entries(proxy: 'required - descriptor or session id')

    # Replace the active request/response substitution rules.
    #{self}.rules(
      proxy: 'required - descriptor or session id',
      rules: 'required - array of phase/field/match/replace hashes'
    )

    # Replay a captured HTTP request with optional mutations.
    #{self}.http_replay(
      proxy: 'required - descriptor or session id',
      request_id: 'required - captured _request_id',
      mutations: 'optional - method, url, path, query, headers, body'
    )

    # Alias of http_replay for pwn_eval callers.
    #{self}.replay(
      proxy: 'required - descriptor or session id',
      request_id: 'required - captured _request_id',
      mutations: 'optional - method, url, path, query, headers, body'
    )

    # Send and capture one HTTP request through the shared rule engine.
    #{self}.exchange(
      proxy: 'required - descriptor or session id',
      request: 'required - method, url, headers, body hash'
    )

    # Stop the listener and flush its HAR.
    #{self}.stop(proxy: 'required - descriptor or session id')

    # Print the module authors.
    #{self}.authors
  "
end

.http_replay(opts = {}) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/pwn/plugins/mitm_proxy.rb', line 102

public_class_method def self.http_replay(opts = {})
  session = lookup(opts)
  entry = entries(proxy: session).find { |row| row[:_request_id] == opts[:request_id].to_s }
  raise ArgumentError, 'unknown request_id' unless entry
  raise ArgumentError, 'opaque CONNECT tunnels cannot be replayed as HTTP' if entry[:_capture] == 'opaque_connect'

  original = entry[:request]
  mutations = (opts[:mutations] || {}).transform_keys(&:to_sym)
  unknown = mutations.keys - i[method url path query headers body]
  raise ArgumentError, "unknown mutations: #{unknown.join(', ')}" unless unknown.empty?

  uri = URI(mutations[:url] || original[:url])
  uri.path = mutations[:path] if mutations.key?(:path)
  uri.query = mutations[:query].is_a?(Hash) ? URI.encode_www_form(mutations[:query]) : mutations[:query] if mutations.key?(:query)
  headers = original[:headers].to_h { |h| [h[:name].downcase, h[:value]] }
  (mutations[:headers] || {}).each { |k, v| v.nil? ? headers.delete(k.downcase) : headers[k.downcase] = v }
  post = original[:postData] || {}
  body = post[:encoding] == 'base64' ? Base64.strict_decode64(post[:text]) : post[:text].to_s
  exchange(proxy: session, request: { method: mutations[:method] || original[:method], url: uri.to_s,
                                      headers: headers, body: mutations.fetch(:body, body) })
end

.replay(opts = {}) ⇒ Object 



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# File 'lib/pwn/plugins/mitm_proxy.rb', line 255

public_class_method def self.replay(opts = {})
  _id = opts[:request_id]
  http_replay(opts)
end

.rules(opts = {}) ⇒ Object 



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# File 'lib/pwn/plugins/mitm_proxy.rb', line 95

public_class_method def self.rules(opts = {})
  session = lookup(opts)
  rules = validate_rules(rules: opts[:rules])
  session[:mutex].synchronize { session[:rules] = rules }
  { id: session[:id], rules: rules }
end

.start(opts = {}) ⇒ Object 



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# File 'lib/pwn/plugins/mitm_proxy.rb', line 45

public_class_method def self.start(opts = {})
  raise ArgumentError, 'backend must be native' unless (opts[:backend] || 'native').to_s == 'native'

  id = SecureRandom.hex(12)
  path = File.expand_path(opts[:har_path] || File.join(Dir.tmpdir, "pwn-proxy-#{id}.har"))
  rules = validate_rules(rules: opts[:rules])
  session = { id: id, backend: 'native', har_path: path, rules: rules, entries: [], mutex: Mutex.new,
              timeout: Float(opts[:timeout] || 30), https_capture: opts[:mitm_tls] ? 'TLS MITM' : 'CONNECT metadata only; TLS is not decrypted',
              on_request: opts[:on_request], on_response: opts[:on_response], ca: self_signed_ca }
  server = Server.new(BindAddress: opts[:host] || '127.0.0.1', Port: Integer(opts[:port] || 0),
                      Logger: WEBrick::Log.new(File::NULL), AccessLog: [], PWNSession: session,
                      ProxyContentHandler: lambda { |req, res|
                        next unless req.request_method == 'CONNECT'

                        persist_entry(proxy: session, entry: { _request_id: SecureRandom.hex(12), _capture: 'opaque_connect',
                                                               startedDateTime: Time.now.utc.iso8601, time: 0,
                                                               request: { method: 'CONNECT', url: req.unparsed_uri, headers: [] },
                                                               response: { status: res.status, headers: [], content: { size: 0, mimeType: '', text: '' } },
                                                               cache: {}, timings: { send: 0, wait: 0, receive: 0 } })
                      })
  session.merge!(host: server.config[:BindAddress], port: server.config[:Port], server: server)
  session[:url] = "http://#{session[:host]}:#{session[:port]}"
  LOCK.synchronize { SESSIONS[id] = session }
  session[:thread] = Thread.new { server.start }
  persist(proxy: session)
  descriptor(proxy: session)
rescue StandardError
  server&.shutdown
  LOCK.synchronize { SESSIONS.delete(id) } if id
  raise
end

.stop(opts = {}) ⇒ Object 



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# File 'lib/pwn/plugins/mitm_proxy.rb', line 77

public_class_method def self.stop(opts = {})
  session = lookup(opts)
  session[:server].shutdown
  thread = session[:thread]
  unless thread.join(5)
    thread.kill
    thread.join(1)
  end
  persist(proxy: session)
  LOCK.synchronize { SESSIONS.delete(session[:id]) }
  { stopped: true, id: session[:id], har_path: session[:har_path], entries: session[:entries].length }
end