Python pexpect script to test handling handshake_failure alert between two native RIOT instances

test-handshake-failure.py

#!/usr/bin/env python3

import sys
import os
import pexpect
import time
import signal

serverIP = "<SERVER_IP>"

# server setup
# pexpect.run('make clean')
serverEnv = {
    # "CFLAGS": "-DDTLS_PSK -DTINYDTLS_DEBUG",  # use this line to test handshake failure
    "CFLAGS": "-DTINYDTLS_DEBUG",   # use this line to test normal send should be succesful
    "PORT": "tap0",
}
serverEnv.update(os.environ)
server_logfile = open("server.log", "w")
server = pexpect.spawn('make all term',
                        env=serverEnv,
                        timeout=5, encoding='utf-8',
                        logfile=server_logfile,
                        echo=False)
server.sendline("help")
server.expect("Command .* Description", timeout=None)

# start dtls server
server.sendline("dtlss start")

time.sleep(1)

# client setup
# pexpect.run('make clean')
clientEnv = {
    # "CFLAGS": "-DDTLS_ECC -DTINYDTLS_DEBUG",  # use this line to test handshake failure
    "CFLAGS": "-DTINYDTLS_DEBUG",   # use this line to test normal send should be succesful
    "PORT": "tap1",
}
clientEnv.update(os.environ)
client_logfile = open("client.log", "w")
client = pexpect.spawn('make all term',
                        env=clientEnv,
                        timeout=5, encoding='utf-8',
                        logfile=client_logfile,
                        echo=False)
client.sendline("help")
client.expect("Command .* Description", timeout=None)

# send dtls packet from client
client.sendline("ifconfig")
time.sleep(1)
client.sendline("dtlsc " + serverIP + " TEST")

res = server.expect(["Server: got DTLS Data App", "WARN error while handling handshake packet"])
if res != 0:
    print("server: sent handshake_failure alert")
else:
    print("server: received application data")

res = client.expect(["Client: got DTLS Data App", "Alert: level 2, description 40"])
if res != 0:
    print("client: received handshake_failure alert")
else:
    print("client: received application data")


# make sure client does not hangs
client.sendline("help")
client.expect("Command .* Description")

try:
    os.killpg(os.getpgid(server.pid), signal.SIGKILL)
    os.killpg(os.getpgid(client.pid), signal.SIGKILL)
except ProcessLookupError:
    print("Process already stopped")

server.close()
client.close()