Dash P2P connection example

dash-p2p-version-exchange.py

# From https://bitcoin.stackexchange.com/a/48395
import struct
import socket
import time
import hashlib
import binascii

# Dash Testnet
magic = "cee2caff"

def makeMessage(magic, command, payload):
    checksum = hashlib.sha256(hashlib.sha256(payload).digest()).digest()[0:4]
    return magic.decode("hex") + struct.pack('12sI4s',command,len(payload),checksum) + payload

def makeVersionPayload():
    version = 70214
    services = 0
    timestamp = int(time.time())

    addr_you = "127.0.0.1"
    services_you = 0
    port_you = 19999

    addr_me = "127.0.0.1"
    services_me = 0
    port_me = 19999

    nonce = 0

    user_agent_bytes = 0
    start_height = 0
    relay = 0

    # https://dash-docs.github.io/en/developer-reference#version
    payload = "";
    payload += struct.pack("i",version)
    payload += struct.pack("Q",services)
    payload += struct.pack("q",timestamp)
    payload += struct.pack("Q",services_you)
    payload += struct.pack(">16s",addr_you)
    payload += struct.pack(">H",port_you)
    payload += struct.pack("Q",services_me)
    payload += struct.pack(">16s",addr_me)
    payload += struct.pack(">H",port_me)
    payload += struct.pack("Q",nonce)
    payload += struct.pack("B",user_agent_bytes)
    payload += struct.pack("i",start_height)
    payload += struct.pack("B",relay)
    return payload

ip = socket.gethostbyname("35.230.29.198")
port = 19999
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print "connected to node..."
sock.connect((ip,port))

msg = makeMessage(magic,"version",makeVersionPayload())
print "sending version packet"
sock.send(msg)

while 1:
    msg = sock.recv(2**10)
    if not msg:
        print "done"
        exit()
    else:
        print msg.encode("hex")