from __future__ import print_function import io, os, sys, json, binascii, six, tempfile, zipfile from twisted.internet import reactor, defer from twisted.internet.defer import inlineCallbacks, returnValue from ..twisted.transcribe import Wormhole, WrongPasswordError from ..twisted.transit import TransitReceiver from ..errors import TransferError from .progress import ProgressPrinter APPID = u"lothar.com/wormhole/text-or-file-xfer" class RespondError(Exception): def __init__(self, response): self.response = response def receive_twisted_sync(args): # try to use twisted.internet.task.react(f) here (but it calls sys.exit # directly) d = defer.Deferred() # don't call receive_twisted() until after the reactor is running, so # that if it raises an exception synchronously, we won't stop the reactor # before it starts reactor.callLater(0, d.callback, None) d.addCallback(lambda _: receive_twisted(args)) rc = [] def _done(res): rc.extend([True, res]) reactor.stop() def _err(f): rc.extend([False, f]) reactor.stop() d.addCallbacks(_done, _err) reactor.run() if rc[0]: return rc[1] print(str(rc[1])) rc[1].raiseException() def receive_twisted(args): return TwistedReceiver(args).go() class TwistedReceiver: def __init__(self, args): assert isinstance(args.relay_url, type(u"")) self.args = args def msg(self, *args, **kwargs): print(*args, file=self.args.stdout, **kwargs) # TODO: @handle_server_error @inlineCallbacks def go(self): tor_manager = None if self.args.tor: _start = self.args.timing.add_event("import TorManager") from ..twisted.tor_manager import TorManager self.args.timing.finish_event(_start) tor_manager = TorManager(reactor, timing=self.args.timing) # For now, block everything until Tor has started. Soon: launch # tor in parallel with everything else, make sure the TorManager # can lazy-provide an endpoint, and overlap the startup process # with the user handing off the wormhole code yield tor_manager.start() w = Wormhole(APPID, self.args.relay_url, tor_manager, timing=self.args.timing) rc = yield self._go(w, tor_manager) yield w.close() returnValue(rc) @inlineCallbacks def _go(self, w, tor_manager): yield self.handle_code(w) verifier = yield w.get_verifier() self.show_verifier(verifier) them_d = yield self.get_data(w) try: if "message" in them_d: yield self.handle_text(them_d, w) returnValue(0) if "file" in them_d: f = self.handle_file(them_d) rp = yield self.establish_transit(w, them_d, tor_manager) yield self.transfer_data(rp, f) self.write_file(f) yield self.close_transit(rp) elif "directory" in them_d: f = self.handle_directory(them_d) rp = yield self.establish_transit(w, them_d, tor_manager) yield self.transfer_data(rp, f) self.write_directory(f) yield self.close_transit(rp) else: self.msg(u"I don't know what they're offering\n") self.msg(u"Offer details:", them_d) raise RespondError({"error": "unknown offer type"}) except RespondError as r: data = json.dumps(r.response).encode("utf-8") yield w.send_data(data) returnValue(1) returnValue(0) @inlineCallbacks def handle_code(self, w): code = self.args.code if self.args.zeromode: assert not code code = u"0-" if not code: code = yield w.input_code("Enter receive wormhole code: ", self.args.code_length) yield w.set_code(code) def show_verifier(self, verifier): verifier_hex = binascii.hexlify(verifier).decode("ascii") if self.args.verify: self.msg(u"Verifier %s." % verifier_hex) @inlineCallbacks def get_data(self, w): try: them_bytes = yield w.get_data() except WrongPasswordError as e: raise TransferError(u"ERROR: " + e.explain()) them_d = json.loads(them_bytes.decode("utf-8")) if "error" in them_d: raise TransferError(u"ERROR: " + them_d["error"]) returnValue(them_d) @inlineCallbacks def handle_text(self, them_d, w): # we're receiving a text message self.msg(them_d["message"]) data = json.dumps({"message_ack": "ok"}).encode("utf-8") yield w.send_data(data) def handle_file(self, them_d): file_data = them_d["file"] self.abs_destname = self.decide_destname("file", file_data["filename"]) self.xfersize = file_data["filesize"] self.msg(u"Receiving file (%d bytes) into: %s" % (self.xfersize, os.path.basename(self.abs_destname))) self.ask_permission() tmp_destname = self.abs_destname + ".tmp" return open(tmp_destname, "wb") def handle_directory(self, them_d): file_data = them_d["directory"] zipmode = file_data["mode"] if zipmode != "zipfile/deflated": self.msg(u"Error: unknown directory-transfer mode '%s'" % (zipmode,)) raise RespondError({"error": "unknown mode"}) self.abs_destname = self.decide_destname("directory", file_data["dirname"]) self.xfersize = file_data["zipsize"] self.msg(u"Receiving directory (%d bytes) into: %s/" % (self.xfersize, os.path.basename(self.abs_destname))) self.msg(u"%d files, %d bytes (uncompressed)" % (file_data["numfiles"], file_data["numbytes"])) self.ask_permission() return tempfile.SpooledTemporaryFile() def decide_destname(self, mode, destname): # the basename() is intended to protect us against # "~/.ssh/authorized_keys" and other attacks destname = os.path.basename(destname) if self.args.output_file: destname = self.args.output_file # override abs_destname = os.path.join(self.args.cwd, destname) # get confirmation from the user before writing to the local directory if os.path.exists(abs_destname): self.msg(u"Error: refusing to overwrite existing %s %s" % (mode, destname)) raise RespondError({"error": "%s already exists" % mode}) return abs_destname def ask_permission(self): _start = self.args.timing.add_event("permission", waiting="user") while True and not self.args.accept_file: ok = six.moves.input("ok? (y/n): ") if ok.lower().startswith("y"): break print(u"transfer rejected", file=sys.stderr) self.args.timing.finish_event(_start, answer="no") raise RespondError({"error": "transfer rejected"}) self.args.timing.finish_event(_start, answer="yes") @inlineCallbacks def establish_transit(self, w, them_d, tor_manager): transit_key = w.derive_key(APPID+u"/transit-key") transit_receiver = TransitReceiver(self.args.transit_helper, no_listen=self.args.no_listen, tor_manager=tor_manager, timing=self.args.timing) transit_receiver.set_transit_key(transit_key) direct_hints = yield transit_receiver.get_direct_hints() relay_hints = yield transit_receiver.get_relay_hints() data = json.dumps({ "file_ack": "ok", "transit": { "direct_connection_hints": direct_hints, "relay_connection_hints": relay_hints, }, }).encode("utf-8") yield w.send_data(data) # now receive the rest of the owl tdata = them_d["transit"] transit_receiver.add_their_direct_hints(tdata["direct_connection_hints"]) transit_receiver.add_their_relay_hints(tdata["relay_connection_hints"]) record_pipe = yield transit_receiver.connect() returnValue(record_pipe) @inlineCallbacks def transfer_data(self, record_pipe, f): self.msg(u"Receiving (%s).." % record_pipe.describe()) _start = self.args.timing.add_event("rx file") progress_stdout = self.args.stdout if self.args.hide_progress: progress_stdout = io.StringIO() progress = ProgressPrinter(self.xfersize, progress_stdout) progress.start() received = yield record_pipe.writeToFile(f, self.xfersize, progress.update) progress.finish() self.args.timing.finish_event(_start) # except TransitError if received < self.xfersize: self.msg() self.msg(u"Connection dropped before full file received") self.msg(u"got %d bytes, wanted %d" % (received, self.xfersize)) returnValue(1) # TODO: exit properly assert received == self.xfersize def write_file(self, f): tmp_name = f.name f.close() os.rename(tmp_name, self.abs_destname) self.msg(u"Received file written to %s" % os.path.basename(self.abs_destname)) def write_directory(self, f): self.msg(u"Unpacking zipfile..") _start = self.args.timing.add_event("unpack zip") with zipfile.ZipFile(f, "r", zipfile.ZIP_DEFLATED) as zf: zf.extractall(path=self.abs_destname) # extractall() appears to offer some protection against # malicious pathnames. For example, "/tmp/oops" and # "../tmp/oops" both do the same thing as the (safe) # "tmp/oops". self.msg(u"Received files written to %s/" % os.path.basename(self.abs_destname)) f.close() self.args.timing.finish_event(_start) @inlineCallbacks def close_transit(self, record_pipe): _start = self.args.timing.add_event("ack") yield record_pipe.send_record(b"ok\n") yield record_pipe.close() self.args.timing.finish_event(_start)