#!/usr/bin/python3

'''
Usage:
  for SMTP server test:
    mailtest.py SERVER_NAME submission LOGIN PASSWORD [/tmp/mailfile]
    mailtest.py SERVER_NAME smtps LOGIN PASSWORD [/tmp/mailfile]
  for IMAP server test:
    mailtest.py SERVER_NAME imaps LOGIN PASSWORD

/tmp/mailfile example:
MAIL FROM:<xxxxx@salstar.sk>
RCPT TO:<xxxxx@salstar.sk>
DATA
From: Jan <xxxxx@salstar.sk>
To: SAL <xxxxx@salstar.sk>
Subject: Testing mail
Date: Thu, 1 Apr 2020 14:17:54 -0000
Message-ID: <123xxxxxx@salstar.sk>

Testing.
'''

TLS_CMD = '''openssl s_client -connect %s:%s -starttls %s'''
SSL_CMD = '''openssl s_client -connect %s:%s'''

import sys, socket, time
from subprocess import Popen, PIPE, DEVNULL, TimeoutExpired
from threading  import Thread
from queue import Queue, Empty
from base64 import b64encode

if len(sys.argv)<4:
  print(__doc__)
  sys.exit()

host, port, login, password = sys.argv[1:5]
if len(sys.argv)>5:
  maildata = open(sys.argv[5], "rt").read()
else:
  maildata = None
if port=="submission":
  proto = "smtp"
  cmd = TLS_CMD % (host, port, proto)
elif port=="smtps" or port=="smtp":
  proto = "smtp"
  cmd = SSL_CMD % (host, "smtps")
elif port=="imaps" or port=="9993":
  proto = "imap"
  cmd = SSL_CMD % (host, port)
elif port=="pop3s":
  proto = "pop3"
  cmd = SSL_CMD % (host, port)
elif port=="pop3":
  proto = "pop3"
  cmd = "nc %s 110" % host
else:
  print("ERROR: unknown protocol")
  sys.exit(1)

print("Connecting...")
print(cmd)
conn = Popen(cmd.split(), bufsize=0, stdin=PIPE, stdout=PIPE, stderr=DEVNULL)

def enqueue_output(out, queue):
    for line in iter(out.readline, b''):
        queue.put(line)
    out.close()

queue = Queue()
thread = Thread(target=enqueue_output, args=(conn.stdout, queue))
thread.daemon = True # thread dies with the program
thread.start()

def readall(rows=1):
    while True:
      try:
        out = queue.get_nowait()
        if out:
          print("< ", out.decode("utf-8").rstrip())
          rows -= 1
      except Empty:
        if rows<=0:
          break
        time.sleep(0.1)

def write(data):
    readall()
    print("> ", data)
    #conn.communicate(data.encode("utf-8"))
    try:
      conn.stdin.write(data.encode("utf-8")+b"\n")
    except BrokenPipeError as err:
      print("Broken pipe")

if proto=="smtp":
  write("HELO %s" % socket.gethostname())
  write("AUTH LOGIN")
  write(b64encode(login.encode("utf-8")).decode("utf-8"))
  write(b64encode(password.encode("utf-8")).decode("utf-8"))
  if maildata:
    write(maildata.rstrip("\r\n")+"\n.")
  write("QUIT")
elif proto=="imap":
  write("0 capability")
  write("0 LOGIN %s %s" % (login, password))
  write('0 LIST "" "*"')
  write('0 EXAMINE INBOX')
  write('0 GETQUOTAROOT INBOX')
  write("0 logout")
elif proto=="pop3":
  write("USER %s" % login)
  write("PASS %s" % password)
  write("LIST")
  write("QUIT")
#readall()