Tengo una tarea para escribir un cliente de correo simple y para conectarme a un servidor smtp de google usando sockets (sin usar smtp lib). Sin embargo, emitir un comando MAIL FROM a un servidor smtp de google requiere ssl o tls, y esta es la parte que no puedo entender. Estoy tratando de usar el método ssl.wrap_socket () de Python de esta manera ...

# Create socket called clientSocket and establish a TCP connection with mailserver
clientSocket = socket(AF_INET, SOCK_STREAM)
ssl_clientSocket = ssl.wrap_socket(clientSocket) 
ssl_clientSocket.connect((mailserver, port))

... que no está funcionando. Estoy bastante seguro de que necesito incluir los parámetros ca_certs y ca_reqs, pero no estoy seguro. Y si esto es así, ¿cómo hago para obtener estos certificados? ¿Tengo que descargar openssl y generar uno? ¿Alguien con experiencia con esto? Aquí está el código completo para estar seguro.

from socket import *
import ssl

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"
port = 587

# Create socket called clientSocket and establish a TCP connection with mailserver
clientSocket = socket(AF_INET, SOCK_STREAM)
ssl_clientSocket = ssl.wrap_socket(clientSocket) 
ssl_clientSocket.connect((mailserver, port))

recv = ssl_clientSocket.recv(1024)
print
print recv

# If the first three numbers of what we receive from the SMTP server are not
# '220', we have a problem
if recv[:3] != '220':
    print '220 reply not received from server.'

# Send HELO command and print server response.
heloCommand = 'HELO Alice\r\n'
ssl_clientSocket.send(heloCommand)
recv1 = ssl_clientSocket.recv(1024)
print recv1

# If the first three numbers of the response from the server are not
# '250', we have a problem
if recv1[:3] != '250':
    print '250 reply not received from server.'

# Send MAIL FROM command and print server response.
mailFromCommand = 'MAIL From: [email protected]\r\n'
ssl_clientSocket.send(mailFromCommand)
recv2 = ssl_clientSocket.recv(1024)
print recv2

# If the first three numbers of the response from the server are not
# '250', we have a problem
if recv2[:3] != '250':
    print '250 reply not received from server.'

# Send RCPT TO command and print server response.
rcptToCommand = 'RCPT To: [email protected]\r\n'
ssl_clientSocket.send(rcptToCommand)
recv3 = ssl_clientSocket.recv(1024)
print recv3

# If the first three numbers of the response from the server are not
# '250', we have a problem
if recv3[:3] != '250':
    print '250 reply not received from server.'

# Send DATA command and print server response.
dataCommand = 'DATA\r\n'
ssl_clientSocket.send(dataCommand)
recv4 = ssl_clientSocket.recv(1024)
print recv4

# If the first three numbers of the response from the server are not
# '250', we have a problem
if recv4[:3] != '250':
    print '250 reply not received from server.'

# Send message data.
ssl_clientSocket.send(msg)

# Message ends with a single period.
ssl_clientSocket.send(endmsg)

# Send QUIT command and get server response.
quitCommand = 'QUIT\r\n'
ssl_clientSocket.send(quitCommand)
recv5 = ssl_clientSocket.recv(I1024)
print recv5

# If the first three numbers of the response from the server are not
# '250', we have a problem
if recv5[:3] != '221':
    print '221 reply not received from server.'