The Magic-Wormhole API¶
This library provides a mechanism to securely transfer small amounts of data between two computers. Both machines must be connected to the internet, but they do not need to have public IP addresses or know how to contact each other ahead of time.
Security and connectivity is provided by means of a “wormhole code”: a short string that is transcribed from one machine to the other by the users at the keyboard. This works in conjunction with a baked-in “mailbox server” that relays information from one machine to the other.
The “Wormhole” object provides a secure record pipe between any two programs that use the same wormhole code (and are configured with the same application ID and mailbox server). Each side can send multiple messages to the other, but the encrypted data for all messages must pass through (and be temporarily stored on) the mailbox server, which is a shared resource. For this reason, larger data (including bulk file transfers) should use the Transit class instead. The Wormhole can be used to create a Transit object for this purpose. In the future, Transit will be deprecated, and this functionality will be incorporated directly as a “dilated wormhole”.
A quick example:
import wormhole
async def example_initiator(reactor):
w = wormhole.create(appid, relay_url, reactor)
w.allocate_code()
code = await w.get_code()
print(f"code: {code}")
w.send_message(b"outbound data")
inbound = await w.get_message()
await w.close()
Modes¶
The API comes in two flavors: Delegated and Deferred. Controlling the Wormhole and sending data is identical in both, but they differ in how inbound data and events are delivered to the application.
In Delegated mode, the Wormhole is given a “delegate” object, on which certain methods will be called when information is available (e.g. when the code is established, or when data messages are received). In Deferred mode, the Wormhole object has methods which return Deferreds that will fire at these same times.
Delegated mode:
class MyDelegate:
def wormhole_got_code(self, code):
print("code: %s" % code)
def wormhole_got_message(self, msg): # called for each message
print("got data, %d bytes" % len(msg))
w = wormhole.create(appid, relay_url, reactor, delegate=MyDelegate())
w.allocate_code()
Deferred mode:
async def example_initiator(reactor):
appid = "lothar.com/example"
relay_url = public_relay.MAILBOX_RELAY
w = wormhole.create(appid, relay_url, reactor)
w.allocate_code()
code = await w.get_code()
print(f"code: {code}")
msg = await w.get_message() # gets exactly one message
print(f"got msg: {len(msg)} bytes")
result = await w.close()
print(f"closed: {result}")
Application Identifier¶
Applications using this library must provide an “application
identifier”, a simple string that distinguishes one application from
another. To ensure uniqueness, use a domain name. To use multiple apps
for a single domain, append a URL-like slash and path, like
example.com/app1
. This string must be the same on both clients,
otherwise they will not see each other. The invitation codes are scoped
to the app-id. Note that the app-id must be unicode, not bytes.
Distinct app-ids reduce the size of the connection-id numbers. If fewer than ten Wormholes are active for a given app-id, the connection-id will only need to contain a single digit, even if some other app-id is currently using thousands of concurrent sessions.
Mailbox Servers¶
The library depends upon a “mailbox server” which is a service (on a public IP address) that delivers small encrypted messages from one client to the other. This must be the same for both clients, and is generally baked-in to the application source code or default config.
This library includes the URL of a public mailbox server run by the
author. Application developers can use this one, or they can run their
own (see the
warner/magic-wormhole-mailbox-server
repository) and configure their clients to use it instead. The URL of
the public mailbox server is passed as a unicode string. Note that
because the server actually speaks WebSockets, the URL starts with
ws:
(or wss:
) instead of http:
.
Wormhole Parameters¶
All wormholes must be created with at least three parameters:
appid
: a (unicode) stringrelay_url
: a (unicode) stringreactor
: the Twisted reactor object
In addition to these three, the wormhole.create()
function takes
several optional arguments:
delegate
: provide a Delegate object to enable “delegated mode”, or pass None (the default) to get “deferred mode”journal
: provide a Journal object to enable journaled mode. See journal.md for details. Note that journals only work with delegated mode, not with deferred mode.tor_manager
: to enable Tor support, create awormhole.TorManager
instance and pass it here. This will hide the client’s IP address by proxying all connections (mailbox and transit) through Tor. It also enables connecting to Onion-service transit hints, and (in the future) will enable the creation of Onion-services for transit purposes.timing
: this accepts a DebugTiming instance, mostly for internal diagnostic purposes, to record the transmit/receive timestamps for all messages. Thewormhole --dump-timing=
feature uses this to build a JSON-format data bundle, and themisc/dump-timing.py
tool can build a scrollable timing diagram from these bundles.welcome_handler
: this is a function that will be called when the Mailbox Server’s “welcome” message is received. It is used to display important server messages in an application-specific way.versions
: this can accept a dictionary (JSON-encodable) of data that will be made available to the peer via thegot_version
event. This data is delivered before any data messages, and can be used to indicate peer capabilities.
Code Management¶
Each wormhole connection is defined by a shared secret “wormhole code”. These codes can be created by humans offline (by picking a unique number and some secret words), but are more commonly generated by asking the library to make one. In the “bin/wormhole” file-transfer tool, the default behavior is for the sender’s program to create the code, and for the receiver to type it in.
The code is a (unicode) string in the form NNN-code-words
. The
numeric “NNN” prefix is the “channel id” or “nameplate”, and is a short
integer allocated by talking to the mailbox server. The rest is a
randomly-generated selection from the PGP wordlist, providing a default
of 16 bits of entropy. The initiating program should display this code
to the user, who should transcribe it to the receiving user, who gives
it to their local Wormhole object by calling set_code()
. The
receiving program can also use input_code()
to use a readline-based
input function: this offers tab completion of allocated channel-ids and
known codewords.
The Wormhole object has three APIs for generating or accepting a code:
w.allocate_code(length=2)
: this contacts the Mailbox Server, allocates a short numeric nameplate, chooses a configurable number of random words, then assembles them into the codew.set_code(code)
: this accepts the complete code as an argumenthelper = w.input_code()
: this facilitates interactive entry of the code, with tab-completion. The helper object has methods to return a list of viable completions for whatever portion of the code has been entered so far. A convenience wrapper is provided to attach this to therlcompleter
function of libreadline.
No matter which mode is used, the w.get_code()
Deferred (or
delegate.wormhole_got_code(code)
callback) will fire when the code
is known. get_code
is clearly necessary for allocate_code
, since
there’s no other way to learn what code was created, but it may be
useful in other modes for consistency.
The code-entry Helper object has the following API:
refresh_nameplates()
: requests an updated list of nameplates from the Mailbox Server. These form the first portion of the wormhole code (e.g. “4” in “4-purple-sausages”). Note that they are unicode strings (so “4”, not 4). The Helper will get the response in the background, and calls toget_nameplate_completions()
after the response will use the new list. Calling this afterh.choose_nameplate
will raiseAlreadyChoseNameplateError
.matches = h.get_nameplate_completions(prefix)
: returns (synchronously) a set of completions for the given nameplate prefix, along with the hyphen that always follows the nameplate (and separates the nameplate from the rest of the code). For example, if the server reports nameplates 1, 12, 13, 24, and 170 are in use,get_nameplate_completions("1")
will return{"1-", "12-", "13-", "170-"}
. You may want to sort these before displaying them to the user. RaisesAlreadyChoseNameplateError
if called afterh.choose_nameplate
.h.choose_nameplate(nameplate)
: accepts a string with the chosen nameplate. May only be called once, after whichAlreadyChoseNameplateError
is raised. (in this future, this might return a Deferred that fires (with None) when the nameplate’s wordlist is known (which happens after the nameplate is claimed, requiring a roundtrip to the server)).d = h.when_wordlist_is_available()
: return a Deferred that fires (with None) when the wordlist is known. This can be used to block a readline frontend which has just calledh.choose_nameplate()
until the resulting wordlist is known, which can improve the tab-completion behavior.matches = h.get_word_completions(prefix)
: return (synchronously) a set of completions for the given words prefix. This will include a trailing hyphen if more words are expected. The possible completions depend upon the wordlist in use for the previously-claimed nameplate, so calling this beforechoose_nameplate
will raiseMustChooseNameplateFirstError
. Calling this afterh.choose_words()
will raiseAlreadyChoseWordsError
. Given a prefix like “su”, this returns a set of strings which are potential matches (e.g.{"supportive-", "surrender-", "suspicious-"}
. The prefix should not include the nameplate, but should include whatever words and hyphens have been typed so far (the default wordlist uses alternate lists, where even numbered words have three syllables, and odd numbered words have two, so the completions depend upon how many words are present, not just the partial last word). E.g.get_word_completions("pr")
will return{"processor-", "provincial-", "proximate-"}
, whileget_word_completions("opulent-pr")
will return{"opulent-preclude", "opulent-prefer", "opulent-preshrunk", "opulent-printer", "opulent-prowler"}
(note the lack of a trailing hyphen, because the wordlist is expecting a code of length two). If the wordlist is not yet known, this returns an empty set. All return values will.startswith(prefix)
. The frontend is responsible for sorting the results before display.h.choose_words(words)
: call this when the user is finished typing in the code. It does not return anything, but will cause the Wormhole’sw.get_code()
(or corresponding delegate) to fire, and triggers the wormhole connection process. This accepts a string like “purple-sausages”, without the nameplate. It must be called afterh.choose_nameplate()
orMustChooseNameplateFirstError
will be raised. May only be called once, after whichAlreadyChoseWordsError
is raised.
The input_with_completion
wrapper is a function that knows how to
use the code-entry helper to do tab completion of wormhole codes:
from wormhole import create, input_with_completion
async def example(reactor):
w = create(appid, relay_url, reactor)
input_with_completion("Wormhole code:", w.input_code(), reactor)
code = await w.get_code()
This helper runs python’s (raw) input()
function inside a thread,
since input()
normally blocks.
The two machines participating in the wormhole setup are not
distinguished: it doesn’t matter which one goes first, and both use the
same Wormhole constructor function. However if w.allocate_code()
is
used, only one side should use it.
Providing an invalid nameplate (which is easily caused by cut-and-paste
errors that include an extra space at the beginning, or which copy the
words but not the number) will raise a KeyFormatError
, either in
w.set_code(code)
or in h.choose_nameplate()
.
Offline Codes¶
In most situations, the “sending” or “initiating” side will call
w.allocate_code()
and display the resulting code. The sending human
reads it and speaks, types, performs charades, or otherwise transmits
the code to the receiving human. The receiving human then types it into
the receiving computer, where it either calls w.set_code()
(if the
code is passed in via argv) or w.input_code()
(for interactive
entry).
Usually one machine generates the code, and a pair of humans transcribes
it to the second machine (so w.allocate_code()
on one side, and
w.set_code()
or w.input_code()
on the other). But it is also
possible for the humans to generate the code offline, perhaps at a
face-to-face meeting, and then take the code back to their computers. In
this case, w.set_code()
will be used on both sides. It is unlikely
that the humans will restrict themselves to a pre-established wordlist
when manually generating codes, so the completion feature of
w.input_code()
is not helpful.
When the humans create an invitation code out-of-band, they are responsible for choosing an unused channel-ID (simply picking a random 3-or-more digit number is probably enough), and some random words. Dice, coin flips, shuffled cards, or repeated sampling of a high-resolution stopwatch are all useful techniques. The invitation code uses the same format either way: channel-ID, a hyphen, and an arbitrary string. There is no need to encode the sampled random values (e.g. by using the Diceware wordlist) unless that makes it easier to transcribe: e.g. rolling 6 dice could result in a code like “913-166532”, and flipping 16 coins could result in “123-HTTHHHTTHTTHHTHH”.
Welcome Messages¶
The first message sent by the mailbox server is a “welcome” message (a
dictionary). This is sent as soon as the client connects to the server,
generally before the code is established. Clients should use
await get_welcome()
to get and process the motd
key (and maybe
current_cli_version
) inside the welcome message.
The welcome message serves three main purposes:
notify users about important server changes, such as CAPTCHA requirements driven by overload, or donation requests
enable future protocol negotiation between clients and the server
advise users of the CLI tools (
wormhole send
) to upgrade to a new version
There are three keys currently defined for the welcome message, all of which are optional (the welcome message omits “error” and “motd” unless the server operator needs to signal a problem).
motd
: if this key is present, it will be a string with embedded newlines. The client should display this string to the user, including a note that it comes from the magic-wormhole Mailbox Server and that server’s URL.error
: if present, the server has decided it cannot service this client. The string will be wrapped in aWelcomeError
(which is a subclass ofWormholeError
), and all API calls will signal errors (pending Deferreds will errback). The mailbox connection will be closed.current_cli_version
: if present, the server is advising instances of the CLI tools (thewormhole
command included in the python distribution) that there is a newer release available, thus users should upgrade if they can, because more features will be available if both clients are running the same version. The CLI tools compare this string against their__version__
and can print a short message to stderr if an upgrade is warranted.
The main idea of error
is to allow the server to cleanly inform the
client about some necessary action it didn’t take. The server currently
sends the welcome message as soon as the client connects (even before it
receives the “claim” request), but a future server could wait for a
required client message and signal an error (via the Welcome message) if
it didn’t see this extra message before the CLAIM arrived.
This could enable changes to the protocol, e.g. requiring a CAPTCHA or
proof-of-work token when the server is under DoS attack. The new server
would send the current requirements in an initial message (which old
clients would ignore). New clients would be required to send the token
before their “claim” message. If the server sees “claim” before “token”,
it knows that the client is too old to know about this protocol, and it
could send a “welcome” with an error
field containing instructions
(explaining to the user that the server is under attack, and they must
either upgrade to a client that can speak the new protocol, or wait
until the attack has passed). Either case is better than an opaque
exception later when the required message fails to arrive.
(Note that the server can also send an explicit ERROR message at any time, and the client should react with a ServerError. Versions 0.9.2 and earlier of the library did not pay attention to the ERROR message, hence the server should deliver errors in a WELCOME message if at all possible)
The error
field is handled internally by the Wormhole object. The
other fields can be processed by application, by using
d=w.get_welcome()
. The Deferred will fire with the full welcome
dictionary, so any other keys that a future server might send will be
available to it.
Applications which need to display motd
or an upgrade message, and
wish to do so before using stdin/stdout for interactive code entry
(w.input_code()
) should wait for get_welcome()
before starting
the entry process:
async def go():
w = wormhole.create(appid, relay_url, reactor)
welcome = await w.get_welcome()
if "motd" in welcome:
print(welcome["motd"])
input_with_completion("Wormhole code:", w.input_code(), reactor)
...
Verifier¶
For extra protection against guessing attacks, Wormhole can provide a “Verifier”. This is a moderate-length series of bytes (a SHA256 hash) that is derived from the supposedly-shared session key. If desired, both sides can display this value, and the humans can manually compare them before allowing the rest of the protocol to proceed. If they do not match, then the two programs are not talking to each other (they may both be talking to a man-in-the-middle attacker), and the protocol should be abandoned.
Deferred-mode applications can wait for d=w.get_verifier()
: the
Deferred it returns will fire with the verifier. You can turn this into
hex or Base64 to print it, or render it as ASCII-art, etc.
Asking the wormhole object for the verifier does not affect the flow of
the protocol. To benefit from verification, applications must refrain
from sending any data (with w.send_message(data)
) until after the
verifiers are approved by the user. In addition, applications must queue
or otherwise ignore incoming (received) messages until that point.
However once the verifiers are confirmed, previously-received messages
can be considered valid and processed as usual.
Events¶
As the wormhole connection is established, several events may be dispatched to the application. In Delegated mode, these are dispatched by calling functions on the delegate object. In Deferred mode, the application retrieves Deferred objects from the wormhole, and event dispatch is performed by firing those Deferreds.
Most applications will only use code
, received
, and close
.
code (
code = yield w.get_code()
/dg.wormhole_got_code(code)
): fired when the wormhole code is established, either afterw.allocate_code()
finishes the generation process, or when the Input Helper returned byw.input_code()
has been toldh.set_words()
, or immediately afterw.set_code(code)
is called. This is most useful after callingw.allocate_code()
, to show the generated code to the user so they can transcribe it to their peer.key (
yield w.get_unverified_key()
/dg.wormhole_got_unverified_key(key)
): fired (with the raw master SPAKE2 key) when the key-exchange process has completed and a purported shared key is established. At this point we do not know that anyone else actually shares this key: the peer may have used the wrong code, or may have disappeared altogether. To wait for proof that the key is shared, wait forget_verifier
instead. This event is really only useful for detecting that the initiating peer has disconnected after leaving the initial PAKE message, to display a pacifying message to the user.verifier (
verifier = yield w.get_verifier()
/dg.wormhole_got_verifier(verifier)
: fired when the key-exchange process has completed and a valid VERSION message has arrived. The “verifier” is a byte string with a hash of the shared session key; clients can compare them (probably as hex) to ensure that they’re really talking to each other, and not to a man-in-the-middle. Whenget_verifier
happens, this side knows that someone has used the correct wormhole code; if someone used the wrong code, the VERSION message cannot be decrypted, and the wormhole will be closed instead.versions (
versions = yield w.get_versions()
/dg.wormhole_got_versions(versions)
: fired when the VERSION message arrives from the peer. This fires just afterverified
, but delivers the “app_versions” data (as passed intowormhole.create(versions=)
) instead of the verifier string. This is mostly a hack to make room for forwards-compatible changes to the CLI file-transfer protocol, which sends a request in the first message (rather than merely sending the abilities of each side).received (
yield w.get_message()
/dg.wormhole_got_message(msg)
: fired each time a data message arrives from the peer, with the bytestring that the peer passed intow.send_message(msg)
. This is the primary data-transfer API.closed (
yield w.close()
/dg.wormhole_closed(result)
: fired whenw.close()
has finished shutting down the wormhole, which means all nameplates and mailboxes have been deallocated, and the WebSocket connection has been closed. This also fires if an internal error occurs (specifically WrongPasswordError, which indicates that an invalid encrypted message was received), which also shuts everything down. Theresult
value is an exception (or Failure) object if the wormhole closed badly, or a string like “happy” if it had no problems before shutdown.
Sending Data¶
The main purpose of a Wormhole is to send data. At any point after
construction, callers can invoke w.send_message(msg)
. This will
queue the message if necessary, but (if all goes well) will eventually
result in the peer getting a received
event and the data being
delivered to the application.
Since Wormhole provides an ordered record pipe, each call to
w.send_message
will result in exactly one received
event on the
far side. Records are not split, merged, dropped, or reordered.
Each side can do an arbitrary number of send_message()
calls. The
Wormhole is not meant as a long-term communication channel, but some
protocols work better if they can exchange an initial pair of messages
(perhaps offering some set of negotiable capabilities), and then follow
up with a second pair (to reveal the results of the negotiation). The
Mailbox Server does not currently enforce any particular limits on
number of messages, size of messages, or rate of transmission, but in
general clients are expected to send fewer than a dozen messages, of no
more than perhaps 20kB in size (remember that all these messages are
temporarily stored in a SQLite database on the server). A future version
of the protocol may make these limits more explicit, and will allow
clients to ask for greater capacity when they connect (probably by
passing additional “mailbox attribute” parameters with the
allocate
/claim
/open
messages).
For bulk data transfer, see “transit.md”, or the “Dilation” section below.
Closing¶
When the application is done with the wormhole, it should call
w.close()
, and wait for a closed
event. This ensures that all
server-side resources are released (allowing the nameplate to be reused
by some other client), and all network sockets are shut down.
In Deferred mode, this just means waiting for the Deferred returned by
w.close()
to fire. In Delegated mode, this means calling
w.close()
(which doesn’t return anything) and waiting for the
delegate’s wormhole_closed()
method to be called.
w.close()
will errback (with some form of WormholeError
) if
anything went wrong with the process, such as:
WelcomeError
: the server told us to signal an error, probably because the client is too old understand some new protocol featureServerError
: the server rejected something we didLonelyError
: we didn’t hear from the other side, so no key was establishedWrongPasswordError
: we received at least one incorrectly-encrypted message. This probably indicates that the other side used a different wormhole code than we did, perhaps because of a typo, or maybe an attacker tried to guess your code and failed.
If the wormhole was happy at the time it was closed, the w.close()
Deferred will callback (probably with the string “happy”, but this may
change in the future).
Serialization¶
(NOTE: this section is speculative: this code has not yet been written)
Wormhole objects can be serialized. This can be useful for apps which save their own state before shutdown, and restore it when they next start up again.
The w.serialize()
method returns a dictionary which can be JSON
encoded into a unicode string (most applications will probably want to
UTF-8 -encode this into a bytestring before saving on disk somewhere).
To restore a Wormhole, call
wormhole.from_serialized(data, reactor, delegate)
. This will return
a wormhole in roughly the same state as was serialized (of course all
the network connections will be disconnected).
Serialization only works for delegated-mode wormholes (since Deferreds point at functions, which cannot be serialized easily). It also only works for “non-dilated” wormholes (see below).
To ensure correct behavior, serialization should probably only be done in “journaled mode”. See journal.md for details.
If you use serialization, be careful to never use the same partial wormhole object twice.
Dilation¶
(NOTE: this API is still in development)
To send bulk data, or anything more than a handful of messages, a Wormhole can be “dilated” into a form that uses a direct TCP connection between the two endpoints.
All wormholes start out “undilated”. In this state, all messages are
queued on the Mailbox Server for the lifetime of the wormhole, and
server-imposed number/size/rate limits apply. Calling w.dilate()
initiates the dilation process, and eventually yields a set of
Endpoints. Once dilated these endpoints can be used to establish
multiple (encrypted) “subchannel” connections to the other side.
Each subchannel behaves like a regular Twisted ITransport
, so they
can be glued to the Protocol instance of your choice. They also
implement the IConsumer/IProducer interfaces.
These subchannels are durable: as long as the processes on both sides keep running, the subchannel will survive the network connection being dropped. For example, a file transfer can be started from a laptop, then while it is running, the laptop can be closed, moved to a new wifi network, opened back up, and the transfer will resume from the new IP address.
What’s good about a non-dilated wormhole?:
setup is faster: no delay while it tries to make a direct connection
works with “journaled mode”, allowing progress to be made even when both sides are never online at the same time, by serializing the wormhole
What’s good about dilated wormholes?:
they support bulk data transfer
you get flow control (backpressure), and IProducer/IConsumer
throughput is faster: no store-and-forward step
Use non-dilated wormholes when your application only needs to exchange a couple of messages, for example to set up public keys or provision access tokens. Use a dilated wormhole to move files, stream data, etc
Dilated wormholes can provide multiple “subchannels”: these are multiplexed through the single (encrypted) TCP connection. Each subchannel is a separate stream (offering IProducer/IConsumer for flow control), and is opened and closed independently. A special “control channel” is available to both sides so they can coordinate how they use the subchannels.
The d = w.dilate()
Deferred fires with a triple of Endpoints:
d = w.dilate()
def _dilated(res):
(control_channel_ep, subchannel_client_ep, subchannel_server_ep) = res
d.addCallback(_dilated)
The control_channel_ep
endpoint is a client-style endpoint, so both
sides will connect to it with ep.connect(factory)
. This endpoint is
single-use: calling .connect()
a second time will fail. The control
channel is symmetric: it doesn’t matter which side is the
application-level client/server or initiator/responder, if the
application even has such concepts. The two applications can use the
control channel to negotiate who goes first, if necessary.
The subchannel endpoints are not symmetric: for each subchannel, one side must listen as a server, and the other must connect as a client. Subchannels can be established by either side at any time. This supports e.g. bidirectional file transfer, where either user of a GUI app can drop files into the “wormhole” whenever they like.
The subchannel_client_ep
on one side is used to connect to the other
side’s subchannel_server_ep
, and vice versa. The client endpoint is
reusable. The server endpoint is single-use: .listen(factory)
may
only be called once.
Applications are under no obligation to use subchannels: for many use cases, the control channel is enough.
To use subchannels, once the wormhole is dilated and the endpoints are
available, the listening-side application should attach a listener to
the subchannel_server_ep
endpoint:
def _dilated(res):
(control_channel_ep, subchannel_client_ep, subchannel_server_ep) = res
f = Factory(MyListeningProtocol)
subchannel_server_ep.listen(f)
When the connecting-side application wants to connect to that listening
protocol, it should use .connect()
with a suitable connecting
protocol factory:
def _connect():
f = Factory(MyConnectingProtocol)
subchannel_client_ep.connect(f)
For a bidirectional file-transfer application, both sides will establish a listening protocol. Later, if/when the user drops a file on the application window, that side will initiate a connection, use the resulting subchannel to transfer the single file, and then close the subchannel.
def FileSendingProtocol(internet.Protocol):
def __init__(self, metadata, filename):
self.file_metadata = metadata
self.file_name = filename
def connectionMade(self):
self.transport.write(self.file_metadata)
sender = protocols.basic.FileSender()
f = open(self.file_name,"rb")
d = sender.beginFileTransfer(f, self.transport)
d.addBoth(self._done, f)
def _done(res, f):
self.transport.loseConnection()
f.close()
def _send(metadata, filename):
f = protocol.ClientCreator(reactor,
FileSendingProtocol, metadata, filename)
subchannel_client_ep.connect(f)
def FileReceivingProtocol(internet.Protocol):
state = INITIAL
def dataReceived(self, data):
if state == INITIAL:
self.state = DATA
metadata = parse(data)
self.f = open(metadata.filename, "wb")
else:
# local file writes are blocking, so don't bother with IConsumer
self.f.write(data)
def connectionLost(self, reason):
self.f.close()
def _dilated(res):
(control_channel_ep, subchannel_client_ep, subchannel_server_ep) = res
f = Factory(FileReceivingProtocol)
subchannel_server_ep.listen(f)
Bytes, Strings, Unicode, and Python 3¶
All cryptographically-sensitive parameters are passed as bytes (“str” in python2, “bytes” in python3):
verifier string
data in/out
transit records in/out
Other (human-facing) values are always unicode (“unicode” in python2, “str” in python3):
wormhole code
relay URL
transit URLs
transit connection hints (e.g. “host:port”)
application identifier
derived-key “purpose” string:
w.derive_key(PURPOSE, LENGTH)
Full API list¶
action |
Deferred-Mode |
Delegated-Mode |
---|---|---|
. |
d=w.get_welcome() |
dg.wormhole_ got_welcome(welcome) |
w.allocate_code() |
||
h=w.input_code() |
||
w.set_code(code) |
||
. |
d=w.get_code() |
dg.wor mhole_got_code(code) |
. |
d=w. get_unverified_key() |
dg.wormhole_got _unverified_key(key) |
. |
d=w.get_verifier() |
dg.wormhole_go t_verifier(verifier) |
. |
d=w.get_versions() |
dg.wormhole_go t_versions(versions) |
key=w .derive_key(purpose, length) |
||
w.send_message(msg) |
||
. |
d=w.get_message() |
dg.wormh ole_got_message(msg) |
w.close() |
dg.wor mhole_closed(result) |
|
. |
d=w.close() |