Reticulum/RNS/Utilities/Echo.py
2018-04-04 15:26:34 +02:00

253 lines
9.8 KiB
Python

import argparse
import time
import RNS
# Let's define an app name. We'll use this for all
# destinations we create. Since this echo example
# is part of a range of example utilities, we'll put
# them all within the app namespace "example_utilities"
APP_NAME = "example_utilitites"
# This initialisation is executed when the users chooses
# to run as a server
def server(configpath):
# We must first initialise Reticulum
reticulum = RNS.Reticulum(configpath)
# Randomly create a new identity for our echo server
server_identity = RNS.Identity()
# We create a destination that clients can query. We want
# to be able to verify echo replies to our clients, so we
# create a "single" destination that can receive encrypted
# messages. This way the client can send a request and be
# certain that no-one else than this destination was able
# to read it.
echo_destination = RNS.Destination(server_identity, RNS.Destination.IN, RNS.Destination.SINGLE, APP_NAME, "echo", "request")
# Tell the destination which function in our program to
# run when a packet is received.
echo_destination.setCallback(serverCallback)
# Everything's ready!
# Let's Wait for client requests or user input
announceLoop(echo_destination)
def announceLoop(destination):
# Let the user know that everything is ready
RNS.log("Echo server "+RNS.prettyhexrep(destination.hash)+" running, hit enter to send announce (Ctrl-C to quit)")
# We enter a loop that runs until the users exits.
# If the user just hits enter, we will announce our server
# destination on the network, which will let clients know
# how to create messages directed towards it.
while True:
entered = raw_input()
destination.announce()
RNS.log("Sent announce from "+RNS.prettyhexrep(destination.hash))
def serverCallback(message, packet):
# We have received am echo request from a client! When
# a client sends a request, it will include the hash of
# it's identity in the message. Since we know that the
# client has created a listening destination using this
# identity hash, we can construct an outgoing destination
# to direct our response to. The hash is sent in binary
# format, so we encode it as printable hexadecimal first,
# since aspect names need to in printable text.
client_identity_hexhash = message.encode("hex_codec")
# We can now create a destination that will let us reach
# the client which send the echo request.
reply_destination = RNS.Destination(None, RNS.Destination.OUT, RNS.Destination.PLAIN, APP_NAME, "echo", "reply", client_identity_hexhash)
# Let's encode the reply destination hash in a readable
# way, so we can output some info to the user.
reply_destination_hexhash = reply_destination.hash.encode("hex_codec")
# Tell the user that we received an echo request, and
# that we are going to send a reply to the requester.
RNS.log("Received packet from <"+reply_destination_hexhash+">, sending reply")
# To let the client know that we got the echo request,
# we will use the "proof" functions of Reticulum. In most
# applications, the proving of packets will occur fully
# automatically, but in some cases like this, it can be
# beneficial to use the functions manually, since it
# neatly provides functionality that can unequivocally
# prove the receipt of the request to the client.
#
# Using the proof functionality is very simple, we just
# need to call the "prove" method on the packet we wish
# to prove, and specify which destination it should be
# directed to.
packet.prove(reply_destination)
# We need a global list to hold sent echo requests
sent_requests = []
# This initialisation is executed when the users chooses
# to run as a client
def client(destination_hexhash, configpath):
# We need a binary representation of the destination
# hash that was entered on the command line
try:
if len(destination_hexhash) != 20:
raise ValueError("Destination length is invalid, must be 20 hexadecimal characters (10 bytes)")
destination_hash = destination_hexhash.decode("hex")
except:
RNS.log("Invalid destination entered. Check your input!\n")
exit()
# We must first initialise Reticulum
reticulum = RNS.Reticulum(configpath)
# Randomly create a new identity for our echo server
client_identity = RNS.Identity()
# Let's set up a destination for replies to our echo
# requests. This destination will be used by the server
# to direct replies to. We're going to use a "plain"
# destination, so the server can send replies back
# without knowing any public keys of the client. In this
# case, such a design is benificial, since any client
# can send echo requests directly to the server, without
# first having to announce it's destination, or include
# public keys in the echo request
#
# We will use the destination naming convention of:
# example_utilities.echo.reply.<IDENTITY_HASH>
# where the last part is a hex representation of the hash
# of our "client_identity". We need to include this to
# create a unique destination for the server to respond to.
# If we had used a "single" destination, something equivalent
# to this process would have happened automatically.
reply_destination = RNS.Destination(client_identity, RNS.Destination.IN, RNS.Destination.PLAIN, APP_NAME, "echo", "reply", client_identity.hexhash)
# Since we are only expecting packets of the "proof"
# type to reach our reply destination, we just set the
# proof callback (and in this case not the normal
# message callback)
reply_destination.setProofCallback(clientProofCallback)
# Tell the user that the client is ready!
RNS.log("Echo client "+RNS.prettyhexrep(reply_destination.hash)+" ready, hit enter to send echo request (Ctrl-C to quit)")
# We enter a loop that runs until the user exits.
# If the user hits enter, we will try to send an
# echo request to the destination specified on the
# command line.
while True:
raw_input()
# To address the server, we need to know it's public
# key, so we check if Reticulum knows this destination.
# This is done by calling the "recall" method of the
# Identity module. If the destination is known, it will
# return an Identity instance that can be used in
# outgoing destinations.
server_identity = RNS.Identity.recall(destination_hash)
if server_identity != None:
# We got the correct identity instance from the
# recall method, so let's create an outgoing
# destination. We use the naming convention:
# example_utilities.echo.request
# Since this is a "single" destination, the identity
# hash will be automatically added to the end of
# the name.
request_destination = RNS.Destination(server_identity, RNS.Destination.OUT, RNS.Destination.SINGLE, APP_NAME, "echo", "request")
# The destination is ready, so let's create a packet.
# We set the destination to the request_destination
# that was just created, and the only data we add
# is the identity hash of our client identity.
# Including that information will let the server
# create a destination to send replies to.
echo_request = RNS.Packet(request_destination, client_identity.hash)
# Send the packet!
echo_request.send()
# Add the request to our list of sent packets
sent_requests.append(echo_request)
# Tell the user that the echo request was sent
RNS.log("Sent echo request to "+RNS.prettyhexrep(request_destination.hash))
else:
# If we do not know this destination, tell the
# user to wait for an announce to arrive.
RNS.log("Destination is not yet known. Wait for an announce to arrive.")
# This method is called when our reply destination
# receives a proof packet.
def clientProofCallback(proof_packet):
# We save the current time so we can calculate
# round-trip time for the packet
now = time.time()
# Let's look through our list of sent requests,
# and see if we can find one that matches the
# proof we just received.
for unproven_packet in sent_requests:
try:
# Check that the proof hash matches the
# hash of the packet we sent earlier
if unproven_packet.packet_hash == proof_packet.data[:32]:
# We need to actually calidate the proof.
# This is simply done by calling the
# validateProofPacket method on the packet
# we sent earlier.
if unproven_packet.validateProofPacket(proof_packet):
# If the proof is valid, we will calculate
# the round-trip time, and inform the user.
rtt = now - unproven_packet.sent_at
if (rtt >= 1):
rtt = round(rtt, 3)
rttstring = str(rtt)+" seconds"
else:
rtt = round(rtt*1000, 3)
rttstring = str(rtt)+" milliseconds"
RNS.log(
"Valid echo reply, proved by "+RNS.prettyhexrep(unproven_packet.destination.hash)+
", round-trip time was "+rttstring
)
# Perform some cleanup
sent_requests.remove(unproven_packet)
del unproven_packet
else:
# If the proof was invalid, we inform
# the user of this.
RNS.log("Echo reply received, but proof was invalid")
except:
RNS.log("Proof packet received, but packet contained invalid or unparsable data")
if __name__ == "__main__":
# Set up command line arguments and start
# the selected program mode.
try:
parser = argparse.ArgumentParser(description="Simple echo server and client utility")
parser.add_argument("-s", "--server", action="store_true", help="wait for incoming packets from clients")
parser.add_argument("--config", action="store", default=None, help="path to alternative Reticulum config directory", type=str)
parser.add_argument("destination", nargs="?", default=None, help="hexadecimal hash of the server destination", type=str)
args = parser.parse_args()
if args.server:
configarg=None
if args.config:
configarg = args.config
server(configarg)
else:
configarg=None
if args.config:
configarg = args.config
if (args.destination == None):
print("")
parser.print_help()
print("")
client(args.destination, configarg)
except KeyboardInterrupt:
exit()