python - 通过 ssh 使用子进程运行多个命令

Question

我正在尝试打开一个子进程以通过我的服务器上的 SMTP 协议发送电子邮件。为此，我需要一个 TLS 安全通道，因此我需要 SSL 模块。我没有成功，因为我无法通过子进程通过 openssl 进行交互。

这就是我设想我的脚本需要如何工作的方式。

1. 打开 ssl 连接：openssl s_client -connect smtp.server.com:587 -starttls smtp

1.1. 通过此频道通信登录：AUTH PLAIN ENCODEDLOGINSTRING==

1.2. 通过此渠道通信发送邮件：MAIL FROM:myemail@server.com

我的脚本不应该返回任何东西，除了“邮件已发送”。

我该如何做到这一点？

注意：smtplib 在我的作业中使用是非法的。

Answer 1

我发现最好为此使用套接字（不是子进程），然后使用命令“STARTTLS”，然后用 ssl 包装套接字以获得安全的 tls 连接。之后，您可以继续将 rcpt 发送到： 命令等，并通过套接字发送实际邮件。

旁注：我在一个子进程中使用了这个脚本，我需要它来打印 html 格式的东西；但这是我成功的代码。如果你打算使用它，你需要先设置和格式化（使用换行符和东西（以便 smtp 服务器理解））这些变量：发件人、收件人、主题、正文、服务器、用户名、密码和端口。

# check if server is valid
try:
    socket.gethostbyname(server)
except socket.gaierror:
    print("""
    <p>
    Something seems wrong with the server...
    </p>
    """)
    exit()

# make a connection with the server
mailserver = (server, port)
socket.mailsocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket.mailsocket.connect(mailserver)
step1 = socket.mailsocket.recv(1024)
step1 = step1.decode()
if (step1[:3] != '220'):
    print("""
    <p>
    Something seems wrong with the server...
    </p>
    """)
    exit()

# use tls connection with server
starttls = "STARTTLS" + "\r\n"
socket.mailsocket.send(starttls.encode())
step2 = socket.mailsocket.recv(1024)
step2 = step2.decode()
if (step2[:3] != '220'):
    print("""
    <p>
    Something seems wrong with the TLS connection...
    </p>
    """)
    exit()

# now use SSL
ssl = ssl.wrap_socket(socket.mailsocket, ssl_version=ssl.PROTOCOL_TLSv1_2)
socket.mailsocket = ssl

# set username and password and encode
base64_str = ("\x00"+username+"\x00"+password).encode()
base64_str = base64.b64encode(base64_str)
auth = "AUTH PLAIN ".encode()+base64_str+"\r\n".encode()
socket.mailsocket.send(auth)
step3 = socket.mailsocket.recv(1024)
step3 = step3.decode()
if (step3[:3] != '235'):
    print("""
    <p>
    It seems like your username/password combination is incorrect...
    </p>
    """)
    exit()

# set sender address
sender = "mail from: " + sender + "\r\n"
socket.mailsocket.send(sender.encode())
step4 = socket.mailsocket.recv(1024)
step4 = step4.decode()
if (step4[:3] != '250'):
    print("""
    <p>
    It seems like the sender address is incorrect...
    </p>
    """)
    exit()

# set to address
to = "rcpt to: " + to + "\r\n"
socket.mailsocket.send(to.encode())
step5 = socket.mailsocket.recv(1024)
step5 = step5.decode()
if (step5[:3] != '250'):
    print("""
    <p>
    It seems like the destination address is incorrect...
    </p>
    """)
    exit()

# send data command
data = "data\r\n"
socket.mailsocket.send(data.encode())
step6 = socket.mailsocket.recv(1024)
step6 = step6.decode()
if (step6[:3] != '354'):
    print("""
    <p>
    It seems like the server responds different on the DATA command...
    </p>
    """)
    exit()

# send message subject and body
socket.mailsocket.send(subject.encode())
socket.mailsocket.send(body.encode())
step7 = socket.mailsocket.recv(1024)
step7 = step7.decode()
if (step7[:3] != '250'):
    print("""
    <p>
    It seems like there is something wrong with your message body...
    </p>
    """)
    exit()
else:
    print("""
    <p>
    Your message is queued and will sent as soon as possible!
    </p>
    """)
quit = "QUIT\r\n"
socket.mailsocket.send(quit.encode())

step8 = socket.mailsocket.recv(1024)
step8 = step8.decode()
if (step8[:3] == '221'):
    print("""
    <p>
    Closing connection; bye!
    </p>
    """)
socket.mailsocket.close()