SMTPClient.py

import base64
import ssl
from socket import *

unsecure_server = "dist.bhsi.xyz"
unsecure_port = 2525

secure_server = "smtp.gmail.com"
secure_port = 587


def send_mail(mail_from, mail_to, body):
    # SMTP protocol message
    smtp_client_responses = ["EHLO mail.example.com\r\n",
                             "MAIL FROM: <" + mail_from + ">\r\n",
                             "RCPT TO: <" + mail_to + ">\r\n",
                             "DATA\r\n",
                             f"{body}\r\n",
                             ".\r\n",
                             "QUIT\r\n"]

    client_socket = create_socket(unsecure_server, unsecure_port)

    # Send mail
    for i in range(len(smtp_client_responses)):
        client_socket.send(smtp_client_responses[i].encode())
        if i == 4:
            client_socket.send(smtp_client_responses[i + 1].encode())
        client_socket.recv(2048)


def send_secure_mail(user_name, password, mail_from, mail_to, body):
    # Converter user name and password to base64
    user_name = base64_string_converter(user_name)
    password = base64_string_converter(password)

    # Array's with protocol responses and answers
    smtp_client_responses = ["EHLO mail.example.com\r\n",
                             "STARTTLS\r\n",
                             "AUTH LOGIN\r\n",
                             user_name + "\r\n", password + "\r\n",
                             "MAIL FROM: <" + mail_from + ">\r\n",
                             "RCPT TO: <" + mail_to + ">\r\n",
                             "DATA\r\n",
                             f"{body}\r\n.\r\n",
                             "QUIT\r\n"]

    client_socket = create_socket(secure_server, secure_port)

    # Prepare for tls
    for i in range(2):
        client_socket.send(smtp_client_responses[i].encode())
        client_socket.recv(2048)

    # Upgrade connection to TLS
    ctx = ssl.create_default_context()
    client_socket = ctx.wrap_socket(client_socket, server_hostname=secure_server)

    # Authenticate and send mail
    for i in range(2, len(smtp_client_responses)):
        client_socket.send(smtp_client_responses[i].encode())
        client_socket.recv(2048)


def create_socket(server, port):
    client_socket = socket(AF_INET, SOCK_STREAM)
    client_socket.connect((server, port))
    client_socket.recv(2048)

    return client_socket


def image_to_base64(image_path):
    with open(image_path, "rb") as imgFile:
        return base64.b64encode(imgFile.read())


def base64_string_converter(string):
    string_in_bytes = string.encode('utf-8')
    string_in_base64 = base64.b64encode(string_in_bytes)
    result_as_string = string_in_base64.decode('utf-8')
    return result_as_string


def base_64_to_string(bytes_to_conv):
    return bytes_to_conv.decode('utf-8')


def create_image_attachment(body='', image_attachment=''):
    image_base64 = base_64_to_string(image_to_base64(image_attachment))
    msg = f'Content-Type: multipart/mixed; boundary="===============0814515963129319972=="\n' \
          f'MIME-Version: 1.0\n'

    # Text plain
    msg = msg + f'--===============0814515963129319972==\n' \
                f'Content-Type: text/plain; charset="utf-8"\n' \
                f'Content-Transfer-Encoding: quoted-printable\n' \
                f'\n' \
                f'{body}\n' \
                f'\n'

    # Image attachment
    if image_attachment != '':
        msg = msg + '--===============0814515963129319972==\n' \
                    'Content-Type: image/octet_stream\n' \
                    'MIME-Version: 1.0\n' \
                    'Content-Transfer-Encoding: base64\n' \
                    f'Content-Disposition: attachment; filename="{image_attachment}"\n' \
                    '\n' \
                    f'{image_base64}==\n' \
                    '\n' \

    # End of message
    msg = msg + f'--===============0814515963129319972==--'

    return msg


def create_make_body_mailable(body):
    new_body = f'000000000000382db0057f0910d5"\n' \
              f'Content-Type: text/plain; charset="UTF-8"\n' \
              f'Content-Transfer-Encoding: quoted-printable\n' \
              f'\n' \
              f'{body}\n' \
              f'\n' \
              f'000000000000382db0057f0910d5'

    return new_body