TLS connection to smtp.gmail.com isn't working-CodePudding

I'm trying to figure out why the TLS connection to smtp.gmail.com isn't working, the code includes import ssl and I did the HELO before and after the STARTTLS command and then I wrapped the clientSocket with ssl_wrap. I'm entering my email address and password for the authorization. One thing to note is I'm not able to use smtplib. Does anyone know what I'm doing wrong? I can keep checking to see if the error numbers are possibly wrong but it seems to break down at authorization.

Here's the output in the console, after the last line I hit enter and keep getting blank spaces:

Here's the code:

from socket import * 
import ssl
import base64

msg = "\r\n I love computer networks!" 
endmsg = "\r\n.\r\n" 

#----------------------------------------------------------------------
# Choose a mail server (e.g. Google mail server) and call it mailserver 
#----------------------------------------------------------------------
mailserver = 'smtp.gmail.com' 
#mailServer = 'localhost'
mailPort = 587 #25 is standard smtp, 465 is for SSL and 587 for TLS

#---------------------------------------------------------------------------------
# Create socket called clientSocket and establish a TCP connection with mailserver 
#---------------------------------------------------------------------------------
clientSocket = socket(AF_INET, SOCK_STREAM) 
clientSocket.connect((mailserver, mailPort))
recv1 = clientSocket.recv(1024).decode() 
print(recv1) 
if recv1[:3] != '220': #250, 530
    print('220 reply not received from server.')
    
#---------------------------------------------
# Send HELO command and print server response. 
#---------------------------------------------
heloCommand = 'HELO Shane\r\n' 
clientSocket.sendall(heloCommand.encode()) 
recv3 = clientSocket.recv(1024).decode() 
print(recv3) 
if recv3[:3] != '530':  #250
    print('530 reply not received from server.')

#--------------------------------
# Request an encrypted connection
#--------------------------------
command = 'STARTTLS\r\n'.encode()
clientSocket.send(command)
recv2 = clientSocket.recv(1024).decode()
print(recv2)
if recv2[:3] != '220':
    print('recv2:220 reply not received from server')

#-------------------
# Encrypt the socket
#-------------------
ssl_clientSocket = ssl.wrap_socket(clientSocket)

#---------------------------------------------
# Send HELO command and print server response. 
#---------------------------------------------
heloCommand = 'HELO Shane\r\n' 
ssl_clientSocket.sendall(heloCommand.encode()) 
recv3 = ssl_clientSocket.recv(1024).decode() 
#print(recv3) 
if recv3[:3] != '530':  #250
    print('530 reply not received from server.')

#---------------------------------------------
# Send the AUTH LOGIN command and print server response.
#---------------------------------------------
authCommand = 'AUTH LOGIN\r\n'
ssl_clientSocket.write(authCommand.encode())
auth_recv = ssl_clientSocket.read(1024)
if auth_recv[:3] != '334':
    print ('334 reply not received from server')

#---------------------------------------------
# Send username and print server response.
#---------------------------------------------
username = input("Type your username and press enter:")
uname = base64.b64encode(username.encode())
print('\r\n')
ssl_clientSocket.write(uname)
uname_recv = ssl_clientSocket.read(1024)
if uname_recv[:3] != '334':
    print ('334 reply not received from server')

#---------------------------------------------
# Send password and print server response.
#---------------------------------------------
password = input("Type your password and press enter:")
pword = base64.b64encode(password.encode())
#print('\r\n')
ssl_clientSocket.write(pword)
pword_recv = ssl_clientSocket.read(1024)
if pword_recv[:3] != '235':
    print ('235 reply not received from server')

#--------------------------------------------------
# Send MAIL FROM command and print server response. 
#--------------------------------------------------
mailfromCommand = 'MAIL FROM: <[email protected]>\r\n'
ssl_clientSocket.sendall(mailfromCommand.encode())
recv4 = ssl_clientSocket.recv(1024)
print(recv4)
if recv4[:3] != '530': #250, 530
    print('530 reply not received from server.')


#-------------------------------------------------
# Send RCPT TO command and print server response. 
#-------------------------------------------------
rcpttoCommand = 'RCPT TO: <[email protected]>\r\n'
ssl_clientSocket.sendall(rcpttoCommand.encode())
recv5 = ssl_clientSocket.recv(1024)
print(recv5)
if recv5[:3] != '530': #250
    print('rcpt to 530 reply not received from server.')
 
#---------------------------------------------
# Send DATA command and print server response.
#--------------------------------------------- 
dataCommand = 'Data\r\n'
print(dataCommand)
ssl_clientSocket.sendall(dataCommand.encode())
recv6 = ssl_clientSocket.recv(1024)
print(recv6)
if recv6[:3] != '530':  #250? 354, 530
    print('data 530 reply not received from server.')

#---------------------------------------------
# Send message data. 
#---------------------------------------------
message = 'SUBJECT: Obsidian made my best Fallout game'
fallout76 = 'SUBJECT: I’m sorry about Fallout 76\r\n'
ssl_clientSocket.send(fallout76.encode())
ssl_clientSocket.send(message.encode())
ssl_clientSocket.send(msg.encode())

#---------------------------------------------
# Message ends with a single period.
#--------------------------------------------- 
ssl_clientSocket.sendall(message.encode()   endmsg.encode())
recv7 = ssl_clientSocket.recv(1024)
print(recv7)
if recv7[:3] != '530': #250, 530
    print('end msg 530 reply not received from server.')

#---------------------------------------------
# Send QUIT command and get server response. 
#---------------------------------------------
quitCommand = 'Quit\r\n'
print(quitCommand)
ssl_clientSocket.sendall(quitCommand.encode())
recv8 = ssl_clientSocket.recv(1024)
print(recv8)
if recv8[:3] != '221': #250. 221, 530
    print('quit 221 reply not received from server.')

CodePudding user response：

TLS connection to smtp.gmail.com isn't working

Contrary to this claim TLS is working. The TLS upgrade is successful, otherwise further communication would not be possible at all. But HELO after the TLS upgrade works as expected and yields "250 smtp.gmail.com at your service".

What is wrong though is the login process. It fails to send a b"\r\n" after the base64 encoded username and password. This causes the connection to hang since the server expected more data before sending a response back.