"""A POP3 client class.
Based on the J. Myers POP3 draft, Jan. 96
"""
# Author: David Ascher <david_ascher@brown.edu>
# [heavily stealing from nntplib.py]
# Updated: Piers Lauder <piers@cs.su.oz.au> [Jul '97]
# String method conversion and test jig improvements by ESR, February 2001.
# Added the POP3_SSL class. Methods loosely based on IMAP_SSL. Hector Urtubia <urtubia@mrbook.org> Aug 2003
# Example (see the test function at the end of this file)
# Imports
import errno
import re
import socket
try:
import ssl
HAVE_SSL = True
except ImportError:
HAVE_SSL = False
__all__ = ["POP3","error_proto"]
# Exception raised when an error or invalid response is received:
class error_proto(Exception): pass
# Standard Port
POP3_PORT = 110
# POP SSL PORT
POP3_SSL_PORT = 995
# Line terminators (we always output CRLF, but accept any of CRLF, LFCR, LF)
CR = b'\r'
LF = b'\n'
CRLF = CR+LF
# maximal line length when calling readline(). This is to prevent
# reading arbitrary length lines. RFC 1939 limits POP3 line length to
# 512 characters, including CRLF. We have selected 2048 just to be on
# the safe side.
_MAXLINE = 2048
class POP3:
"""This class supports both the minimal and optional command sets.
Arguments can be strings or integers (where appropriate)
(e.g.: retr(1) and retr('1') both work equally well.
Minimal Command Set:
USER name user(name)
PASS string pass_(string)
STAT stat()
LIST [msg] list(msg = None)
RETR msg retr(msg)
DELE msg dele(msg)
NOOP noop()
RSET rset()
QUIT quit()
Optional Commands (some servers support these):
RPOP name rpop(name)
APOP name digest apop(name, digest)
TOP msg n top(msg, n)
UIDL [msg] uidl(msg = None)
CAPA capa()
STLS stls()
UTF8 utf8()
Raises one exception: 'error_proto'.
Instantiate with:
POP3(hostname, port=110)
NB: the POP protocol locks the mailbox from user
authorization until QUIT, so be sure to get in, suck
the messages, and quit, each time you access the
mailbox.
POP is a line-based protocol, which means large mail
messages consume lots of python cycles reading them
line-by-line.
If it's available on your mail server, use IMAP4
instead, it doesn't suffer from the two problems
above.
"""
encoding = 'UTF-8'
def __init__(self, host, port=POP3_PORT,
timeout=socket._GLOBAL_DEFAULT_TIMEOUT):
self.host = host
self.port = port
self._tls_established = False
self.sock = self._create_socket(timeout)
self.file = self.sock.makefile('rb')
self._debugging = 0
self.welcome = self._getresp()
def _create_socket(self, timeout):
return socket.create_connection((self.host, self.port), timeout)
def _putline(self, line):
if self._debugging > 1: print('*put*', repr(line))
self.sock.sendall(line + CRLF)
# Internal: send one command to the server (through _putline())
def _putcmd(self, line):
if self._debugging: print('*cmd*', repr(line))
line = bytes(line, self.encoding)
self._putline(line)
# Internal: return one line from the server, stripping CRLF.
# This is where all the CPU time of this module is consumed.
# Raise error_proto('-ERR EOF') if the connection is closed.
def _getline(self):
line = self.file.readline(_MAXLINE + 1)
if len(line) > _MAXLINE:
raise error_proto('line too long')
if self._debugging > 1: print('*get*', repr(line))
if not line: raise error_proto('-ERR EOF')
octets = len(line)
# server can send any combination of CR & LF
# however, 'readline()' returns lines ending in LF
# so only possibilities are ...LF, ...CRLF, CR...LF
if line[-2:] == CRLF:
return line[:-2], octets
if line[:1] == CR:
return line[1:-1], octets
return line[:-1], octets
# Internal: get a response from the server.
# Raise 'error_proto' if the response doesn't start with '+'.
def _getresp(self):
resp, o = self._getline()
if self._debugging > 1: print('*resp*', repr(resp))
if not resp.startswith(b'+'):
raise error_proto(resp)
return resp
# Internal: get a response plus following text from the server.
def _getlongresp(self):
resp = self._getresp()
list = []; octets = 0
line, o = self._getline()
while line != b'.':
if line.startswith(b'..'):
o = o-1
line = line[1:]
octets = octets + o
list.append(line)
line, o = self._getline()
return resp, list, octets
# Internal: send a command and get the response
def _shortcmd(self, line):
self._putcmd(line)
return self._getresp()
# Internal: send a command and get the response plus following text
def _longcmd(self, line):
self._putcmd(line)
return self._getlongresp()
# These can be useful:
def getwelcome(self):
return self.welcome
def set_debuglevel(self, level):
self._debugging = level
# Here are all the POP commands:
def user(self, user):
"""Send user name, return response
(should indicate password required).
"""
return self._shortcmd('USER %s' % user)
def pass_(self, pswd):
"""Send password, return response
(response includes message count, mailbox size).
NB: mailbox is locked by server from here to 'quit()'
"""
return self._shortcmd('PASS %s' % pswd)
def stat(self):
"""Get mailbox status.
Result is tuple of 2 ints (message count, mailbox size)
"""
retval = self._shortcmd('STAT')
rets = retval.split()
if self._debugging: print('*stat*', repr(rets))
numMessages = int(rets[1])
sizeMessages = int(rets[2])
return (numMessages, sizeMessages)
def list(self, which=None):
"""Request listing, return result.
Result without a message number argument is in form
['response', ['mesg_num octets', ...], octets].
Result when a message number argument is given is a
single response: the "scan listing" for that message.
"""
if which is not None:
return self._shortcmd('LIST %s' % which)
return self._longcmd('LIST')
def retr(self, which):
"""Retrieve whole message number 'which'.
Result is in form ['response', ['line', ...], octets].
"""
return self._longcmd('RETR %s' % which)
def dele(self, which):
"""Delete message number 'which'.
Result is 'response'.
"""
return self._shortcmd('DELE %s' % which)
def noop(self):
"""Does nothing.
One supposes the response indicates the server is alive.
"""
return self._shortcmd('NOOP')
def rset(self):
"""Unmark all messages marked for deletion."""
return self._shortcmd('RSET')
def quit(self):
"""Signoff: commit changes on server, unlock mailbox, close connection."""
resp = self._shortcmd('QUIT')
self.close()
return resp
def close(self):
"""Close the connection without assuming anything about it."""
try:
file = self.file
self.file = None
if file is not None:
file.close()
finally:
sock = self.sock
self.sock = None
if sock is not None:
try:
sock.shutdown(socket.SHUT_RDWR)
except OSError as exc:
# The server might already have closed the connection.
# On Windows, this may result in WSAEINVAL (error 10022):
# An invalid operation was attempted.
if (exc.errno != errno.ENOTCONN
and getattr(exc, 'winerror', 0) != 10022):
raise
finally:
sock.close()
#__del__ = quit
# optional commands:
def rpop(self, user):
"""Not sure what this does."""
return self._shortcmd('RPOP %s' % user)
timestamp = re.compile(br'\+OK.[^<]*(<.*>)')
def apop(self, user, password):
"""Authorisation
- only possible if server has supplied a timestamp in initial greeting.
Args:
user - mailbox user;
password - mailbox password.
NB: mailbox is locked by server from here to 'quit()'
"""
secret = bytes(password, self.encoding)
m = self.timestamp.match(self.welcome)
if not m:
raise error_proto('-ERR APOP not supported by server')
import hashlib
digest = m.group(1)+secret
digest = hashlib.md5(digest).hexdigest()
return self._shortcmd('APOP %s %s' % (user, digest))
def top(self, which, howmuch):
"""Retrieve message header of message number 'which'
and first 'howmuch' lines of message body.
Result is in form ['response', ['line', ...], octets].
"""
return self._longcmd('TOP %s %s' % (which, howmuch))
def uidl(self, which=None):
"""Return message digest (unique id) list.
If 'which', result contains unique id for that message
in the form 'response mesgnum uid', otherwise result is
the list ['response', ['mesgnum uid', ...], octets]
"""
if which is not None:
return self._shortcmd('UIDL %s' % which)
return self._longcmd('UIDL')
def utf8(self):
"""Try to enter UTF-8 mode (see RFC 6856). Returns server response.
"""
return self._shortcmd('UTF8')
def capa(self):
"""Return server capabilities (RFC 2449) as a dictionary
>>> c=poplib.POP3('localhost')
>>> c.capa()
{'IMPLEMENTATION': ['Cyrus', 'POP3', 'server', 'v2.2.12'],
'TOP': [], 'LOGIN-DELAY': ['0'], 'AUTH-RESP-CODE': [],
'EXPIRE': ['NEVER'], 'USER': [], 'STLS': [], 'PIPELINING': [],
'UIDL': [], 'RESP-CODES': []}
>>>
Really, according to RFC 2449, the cyrus folks should avoid
having the implementation split into multiple arguments...
"""
def _parsecap(line):
lst = line.decode('ascii').split()
return lst[0], lst[1:]
caps = {}
try:
resp = self._longcmd('CAPA')
rawcaps = resp[1]
for capline in rawcaps:
capnm, capargs = _parsecap(capline)
caps[capnm] = capargs
except error_proto as _err:
raise error_proto('-ERR CAPA not supported by server')
return caps
def stls(self, context=None):
"""Start a TLS session on the active connection as specified in RFC 2595.
context - a ssl.SSLContext
"""
if not HAVE_SSL:
raise error_proto('-ERR TLS support missing')
if self._tls_established:
raise error_proto('-ERR TLS session already established')
caps = self.capa()
if not 'STLS' in caps:
raise error_proto('-ERR STLS not supported by server')
if context is None:
context = ssl._create_stdlib_context()
resp = self._shortcmd('STLS')
self.sock = context.wrap_socket(self.sock,
server_hostname=self.host)
self.file = self.sock.makefile('rb')
self._tls_established = True
return resp
if HAVE_SSL:
class POP3_SSL(POP3):
"""POP3 client class over SSL connection
Instantiate with: POP3_SSL(hostname, port=995, keyfile=None, certfile=None,
context=None)
hostname - the hostname of the pop3 over ssl server
port - port number
keyfile - PEM formatted file that contains your private key
certfile - PEM formatted certificate chain file
context - a ssl.SSLContext
See the methods of the parent class POP3 for more documentation.
"""
def __init__(self, host, port=POP3_SSL_PORT, keyfile=None, certfile=None,
timeout=socket._GLOBAL_DEFAULT_TIMEOUT, context=None):
if context is not None and keyfile is not None:
raise ValueError("context and keyfile arguments are mutually "
"exclusive")
if context is not None and certfile is not None:
raise ValueError("context and certfile arguments are mutually "
"exclusive")
if keyfile is not None or certfile is not None:
import warnings
warnings.warn("keyfile and certfile are deprecated, use a "
"custom context instead", DeprecationWarning, 2)
self.keyfile = keyfile
self.certfile = certfile
if context is None:
context = ssl._create_stdlib_context(certfile=certfile,
keyfile=keyfile)
self.context = context
POP3.__init__(self, host, port, timeout)
def _create_socket(self, timeout):
sock = POP3._create_socket(self, timeout)
sock = self.context.wrap_socket(sock,
server_hostname=self.host)
return sock
def stls(self, keyfile=None, certfile=None, context=None):
"""The method unconditionally raises an exception since the
STLS command doesn't make any sense on an already established
SSL/TLS session.
"""
raise error_proto('-ERR TLS session already established')
__all__.append("POP3_SSL")
if __name__ == "__main__":
import sys
a = POP3(sys.argv[1])
print(a.getwelcome())
a.user(sys.argv[2])
a.pass_(sys.argv[3])
a.list()
(numMsgs, totalSize) = a.stat()
for i in range(1, numMsgs + 1):
(header, msg, octets) = a.retr(i)
print("Message %d:" % i)
for line in msg:
print(' ' + line)
print('-----------------------')
a.quit()