| gvSIG desktop 1

"""IMAP4 client.

Based on RFC 2060.

Public class:           IMAP4

Public variable:        Debug

Public functions:       Internaldate2tuple

                        Int2AP

                        ParseFlags

                        Time2Internaldate

"""

# Author: Piers Lauder <piers@cs.su.oz.au> December 1997.

#

# Authentication code contributed by Donn Cave <donn@u.washington.edu> June 1998.

# String method conversion by ESR, February 2001.

__version__ = "2.40"

import binascii, re, socket, time, random, sys

__all__ = ["IMAP4", "Internaldate2tuple",

           "Int2AP", "ParseFlags", "Time2Internaldate"]

#       Globals

CRLF = '\r\n'

Debug = 0

IMAP4_PORT = 143

AllowedVersions = ('IMAP4REV1', 'IMAP4')        # Most recent first

#       Commands

Commands = {

        # name            valid states

        'APPEND':       ('AUTH', 'SELECTED'),

        'AUTHENTICATE': ('NONAUTH',),

        'CAPABILITY':   ('NONAUTH', 'AUTH', 'SELECTED', 'LOGOUT'),

        'CHECK':        ('SELECTED',),

        'CLOSE':        ('SELECTED',),

        'COPY':         ('SELECTED',),

        'CREATE':       ('AUTH', 'SELECTED'),

        'DELETE':       ('AUTH', 'SELECTED'),

        'EXAMINE':      ('AUTH', 'SELECTED'),

        'EXPUNGE':      ('SELECTED',),

        'FETCH':        ('SELECTED',),

        'LIST':         ('AUTH', 'SELECTED'),

        'LOGIN':        ('NONAUTH',),

        'LOGOUT':       ('NONAUTH', 'AUTH', 'SELECTED', 'LOGOUT'),

        'LSUB':         ('AUTH', 'SELECTED'),

        'NOOP':         ('NONAUTH', 'AUTH', 'SELECTED', 'LOGOUT'),

        'PARTIAL':      ('SELECTED',),

        'RENAME':       ('AUTH', 'SELECTED'),

        'SEARCH':       ('SELECTED',),

        'SELECT':       ('AUTH', 'SELECTED'),

        'STATUS':       ('AUTH', 'SELECTED'),

        'STORE':        ('SELECTED',),

        'SUBSCRIBE':    ('AUTH', 'SELECTED'),

        'UID':          ('SELECTED',),

        'UNSUBSCRIBE':  ('AUTH', 'SELECTED'),

        }

#       Patterns to match server responses

Continuation = re.compile(r'\+( (?P<data>.*))?')

Flags = re.compile(r'.*FLAGS \((?P<flags>[^\)]*)\)')

InternalDate = re.compile(r'.*INTERNALDATE "'

        r'(?P<day>[ 123][0-9])-(?P<mon>[A-Z][a-z][a-z])-(?P<year>[0-9][0-9][0-9][0-9])'

        r' (?P<hour>[0-9][0-9]):(?P<min>[0-9][0-9]):(?P<sec>[0-9][0-9])'

        r' (?P<zonen>[-+])(?P<zoneh>[0-9][0-9])(?P<zonem>[0-9][0-9])'

        r'"')

Literal = re.compile(r'.*{(?P<size>\d+)}$')

Response_code = re.compile(r'\[(?P<type>[A-Z-]+)( (?P<data>[^\]]*))?\]')

Untagged_response = re.compile(r'\* (?P<type>[A-Z-]+)( (?P<data>.*))?')

Untagged_status = re.compile(r'\* (?P<data>\d+) (?P<type>[A-Z-]+)( (?P<data2>.*))?')

class IMAP4:

    """IMAP4 client class.

    Instantiate with: IMAP4([host[, port]])

            host - host's name (default: localhost);

            port - port number (default: standard IMAP4 port).

    All IMAP4rev1 commands are supported by methods of the same

    name (in lower-case).

    All arguments to commands are converted to strings, except for

    AUTHENTICATE, and the last argument to APPEND which is passed as

    an IMAP4 literal.  If necessary (the string contains any

    non-printing characters or white-space and isn't enclosed with

    either parentheses or double quotes) each string is quoted.

    However, the 'password' argument to the LOGIN command is always

    quoted.  If you want to avoid having an argument string quoted

    (eg: the 'flags' argument to STORE) then enclose the string in

    parentheses (eg: "(\Deleted)").

    Each command returns a tuple: (type, [data, ...]) where 'type'

    is usually 'OK' or 'NO', and 'data' is either the text from the

    tagged response, or untagged results from command.

    Errors raise the exception class <instance>.error("<reason>").

    IMAP4 server errors raise <instance>.abort("<reason>"),

    which is a sub-class of 'error'. Mailbox status changes

    from READ-WRITE to READ-ONLY raise the exception class

    <instance>.readonly("<reason>"), which is a sub-class of 'abort'.

    "error" exceptions imply a program error.

    "abort" exceptions imply the connection should be reset, and

            the command re-tried.

    "readonly" exceptions imply the command should be re-tried.

    Note: to use this module, you must read the RFCs pertaining

    to the IMAP4 protocol, as the semantics of the arguments to

    each IMAP4 command are left to the invoker, not to mention

    the results.

    """

    class error(Exception): pass    # Logical errors - debug required

    class abort(error): pass        # Service errors - close and retry

    class readonly(abort): pass     # Mailbox status changed to READ-ONLY

    mustquote = re.compile(r"[^\w!#$%&'*+,.:;<=>?^`|~-]")

    def __init__(self, host = '', port = IMAP4_PORT):

        self.host = host

        self.port = port

        self.debug = Debug

        self.state = 'LOGOUT'

        self.literal = None             # A literal argument to a command

        self.tagged_commands = {}       # Tagged commands awaiting response

        self.untagged_responses = {}    # {typ: [data, ...], ...}

        self.continuation_response = '' # Last continuation response

        self.is_readonly = None         # READ-ONLY desired state

        self.tagnum = 0

        # Open socket to server.

        self.open(host, port)

        # Create unique tag for this session,

        # and compile tagged response matcher.

        self.tagpre = Int2AP(random.randint(0, 31999))

        self.tagre = re.compile(r'(?P<tag>'

                        + self.tagpre

                        + r'\d+) (?P<type>[A-Z]+) (?P<data>.*)')

        # Get server welcome message,

        # request and store CAPABILITY response.

        if __debug__:

            if self.debug >= 1:

                _mesg('new IMAP4 connection, tag=%s' % self.tagpre)

        self.welcome = self._get_response()

        if self.untagged_responses.has_key('PREAUTH'):

            self.state = 'AUTH'

        elif self.untagged_responses.has_key('OK'):

            self.state = 'NONAUTH'

        else:

            raise self.error(self.welcome)

        cap = 'CAPABILITY'

        self._simple_command(cap)

        if not self.untagged_responses.has_key(cap):

            raise self.error('no CAPABILITY response from server')

        self.capabilities = tuple(self.untagged_responses[cap][-1].upper().split())

        if __debug__:

            if self.debug >= 3:

                _mesg('CAPABILITIES: %s' % `self.capabilities`)

        for version in AllowedVersions:

            if not version in self.capabilities:

                continue

            self.PROTOCOL_VERSION = version

            return

        raise self.error('server not IMAP4 compliant')

    def __getattr__(self, attr):

        #       Allow UPPERCASE variants of IMAP4 command methods.

        if Commands.has_key(attr):

            return eval("self.%s" % attr.lower())

        raise AttributeError("Unknown IMAP4 command: '%s'" % attr)

    #       Public methods

    def open(self, host, port):

        """Setup 'self.sock' and 'self.file'."""

        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

        self.sock.connect((self.host, self.port))

        self.file = self.sock.makefile('rb')

    def recent(self):

        """Return most recent 'RECENT' responses if any exist,

        else prompt server for an update using the 'NOOP' command.

        (typ, [data]) = <instance>.recent()

        'data' is None if no new messages,

        else list of RECENT responses, most recent last.

        """

        name = 'RECENT'

        typ, dat = self._untagged_response('OK', [None], name)

        if dat[-1]:

            return typ, dat

        typ, dat = self.noop()  # Prod server for response

        return self._untagged_response(typ, dat, name)

    def response(self, code):

        """Return data for response 'code' if received, or None.

        Old value for response 'code' is cleared.

        (code, [data]) = <instance>.response(code)

        """

        return self._untagged_response(code, [None], code.upper())

    def socket(self):

        """Return socket instance used to connect to IMAP4 server.

        socket = <instance>.socket()

        """

        return self.sock

    #       IMAP4 commands

    def append(self, mailbox, flags, date_time, message):

        """Append message to named mailbox.

        (typ, [data]) = <instance>.append(mailbox, flags, date_time, message)

                All args except `message' can be None.

        """

        name = 'APPEND'

        if not mailbox:

            mailbox = 'INBOX'

        if flags:

            if (flags[0],flags[-1]) != ('(',')'):

                flags = '(%s)' % flags

        else:

            flags = None

        if date_time:

            date_time = Time2Internaldate(date_time)

        else:

            date_time = None

        self.literal = message

        return self._simple_command(name, mailbox, flags, date_time)

    def authenticate(self, mechanism, authobject):

        """Authenticate command - requires response processing.

        'mechanism' specifies which authentication mechanism is to

        be used - it must appear in <instance>.capabilities in the

        form AUTH=<mechanism>.

        'authobject' must be a callable object:

                data = authobject(response)

        It will be called to process server continuation responses.

        It should return data that will be encoded and sent to server.

        It should return None if the client abort response '*' should

        be sent instead.

        """

        mech = mechanism.upper()

        cap = 'AUTH=%s' % mech

        if not cap in self.capabilities:

            raise self.error("Server doesn't allow %s authentication." % mech)

        self.literal = _Authenticator(authobject).process

        typ, dat = self._simple_command('AUTHENTICATE', mech)

        if typ != 'OK':

            raise self.error(dat[-1])

        self.state = 'AUTH'

        return typ, dat

    def check(self):

        """Checkpoint mailbox on server.

        (typ, [data]) = <instance>.check()

        """

        return self._simple_command('CHECK')

    def close(self):

        """Close currently selected mailbox.

        Deleted messages are removed from writable mailbox.

        This is the recommended command before 'LOGOUT'.

        (typ, [data]) = <instance>.close()

        """

        try:

            typ, dat = self._simple_command('CLOSE')

        finally:

            self.state = 'AUTH'

        return typ, dat

    def copy(self, message_set, new_mailbox):

        """Copy 'message_set' messages onto end of 'new_mailbox'.

        (typ, [data]) = <instance>.copy(message_set, new_mailbox)

        """

        return self._simple_command('COPY', message_set, new_mailbox)

    def create(self, mailbox):

        """Create new mailbox.

        (typ, [data]) = <instance>.create(mailbox)

        """

        return self._simple_command('CREATE', mailbox)

    def delete(self, mailbox):

        """Delete old mailbox.

        (typ, [data]) = <instance>.delete(mailbox)

        """

        return self._simple_command('DELETE', mailbox)

    def expunge(self):

        """Permanently remove deleted items from selected mailbox.

        Generates 'EXPUNGE' response for each deleted message.

        (typ, [data]) = <instance>.expunge()

        'data' is list of 'EXPUNGE'd message numbers in order received.

        """

        name = 'EXPUNGE'

        typ, dat = self._simple_command(name)

        return self._untagged_response(typ, dat, name)

    def fetch(self, message_set, message_parts):

        """Fetch (parts of) messages.

        (typ, [data, ...]) = <instance>.fetch(message_set, message_parts)

        'message_parts' should be a string of selected parts

        enclosed in parentheses, eg: "(UID BODY[TEXT])".

        'data' are tuples of message part envelope and data.

        """

        name = 'FETCH'

        typ, dat = self._simple_command(name, message_set, message_parts)

        return self._untagged_response(typ, dat, name)

    def list(self, directory='""', pattern='*'):

        """List mailbox names in directory matching pattern.

        (typ, [data]) = <instance>.list(directory='""', pattern='*')

        'data' is list of LIST responses.

        """

        name = 'LIST'

        typ, dat = self._simple_command(name, directory, pattern)

        return self._untagged_response(typ, dat, name)

    def login(self, user, password):

        """Identify client using plaintext password.

        (typ, [data]) = <instance>.login(user, password)

        NB: 'password' will be quoted.

        """

        #if not 'AUTH=LOGIN' in self.capabilities:

        #       raise self.error("Server doesn't allow LOGIN authentication." % mech)

        typ, dat = self._simple_command('LOGIN', user, self._quote(password))

        if typ != 'OK':

            raise self.error(dat[-1])

        self.state = 'AUTH'

        return typ, dat

    def logout(self):

        """Shutdown connection to server.

        (typ, [data]) = <instance>.logout()

        Returns server 'BYE' response.

        """

        self.state = 'LOGOUT'

        try: typ, dat = self._simple_command('LOGOUT')

        except: typ, dat = 'NO', ['%s: %s' % sys.exc_info()[:2]]

        self.file.close()

        self.sock.close()

        if self.untagged_responses.has_key('BYE'):

            return 'BYE', self.untagged_responses['BYE']

        return typ, dat

    def lsub(self, directory='""', pattern='*'):

        """List 'subscribed' mailbox names in directory matching pattern.

        (typ, [data, ...]) = <instance>.lsub(directory='""', pattern='*')

        'data' are tuples of message part envelope and data.

        """

        name = 'LSUB'

        typ, dat = self._simple_command(name, directory, pattern)

        return self._untagged_response(typ, dat, name)

    def noop(self):

        """Send NOOP command.

        (typ, data) = <instance>.noop()

        """

        if __debug__:

            if self.debug >= 3:

                _dump_ur(self.untagged_responses)

        return self._simple_command('NOOP')

    def partial(self, message_num, message_part, start, length):

        """Fetch truncated part of a message.

        (typ, [data, ...]) = <instance>.partial(message_num, message_part, start, length)

        'data' is tuple of message part envelope and data.

        """

        name = 'PARTIAL'

        typ, dat = self._simple_command(name, message_num, message_part, start, length)

        return self._untagged_response(typ, dat, 'FETCH')

    def rename(self, oldmailbox, newmailbox):

        """Rename old mailbox name to new.

        (typ, data) = <instance>.rename(oldmailbox, newmailbox)

        """

        return self._simple_command('RENAME', oldmailbox, newmailbox)

    def search(self, charset, *criteria):

        """Search mailbox for matching messages.

        (typ, [data]) = <instance>.search(charset, criterium, ...)

        'data' is space separated list of matching message numbers.

        """

        name = 'SEARCH'

        if charset:

            charset = 'CHARSET ' + charset

        typ, dat = apply(self._simple_command, (name, charset) + criteria)

        return self._untagged_response(typ, dat, name)

    def select(self, mailbox='INBOX', readonly=None):

        """Select a mailbox.

        Flush all untagged responses.

        (typ, [data]) = <instance>.select(mailbox='INBOX', readonly=None)

        'data' is count of messages in mailbox ('EXISTS' response).

        """

        # Mandated responses are ('FLAGS', 'EXISTS', 'RECENT', 'UIDVALIDITY')

        self.untagged_responses = {}    # Flush old responses.

        self.is_readonly = readonly

        if readonly:

            name = 'EXAMINE'

        else:

            name = 'SELECT'

        typ, dat = self._simple_command(name, mailbox)

        if typ != 'OK':

            self.state = 'AUTH'     # Might have been 'SELECTED'

            return typ, dat

        self.state = 'SELECTED'

        if self.untagged_responses.has_key('READ-ONLY') \

                and not readonly:

            if __debug__:

                if self.debug >= 1:

                    _dump_ur(self.untagged_responses)

            raise self.readonly('%s is not writable' % mailbox)

        return typ, self.untagged_responses.get('EXISTS', [None])

    def status(self, mailbox, names):

        """Request named status conditions for mailbox.

        (typ, [data]) = <instance>.status(mailbox, names)

        """

        name = 'STATUS'

        if self.PROTOCOL_VERSION == 'IMAP4':

            raise self.error('%s unimplemented in IMAP4 (obtain IMAP4rev1 server, or re-code)' % name)

        typ, dat = self._simple_command(name, mailbox, names)

        return self._untagged_response(typ, dat, name)

    def store(self, message_set, command, flags):

        """Alters flag dispositions for messages in mailbox.

        (typ, [data]) = <instance>.store(message_set, command, flags)

        """

        if (flags[0],flags[-1]) != ('(',')'):

            flags = '(%s)' % flags  # Avoid quoting the flags

        typ, dat = self._simple_command('STORE', message_set, command, flags)

        return self._untagged_response(typ, dat, 'FETCH')

    def subscribe(self, mailbox):

        """Subscribe to new mailbox.

        (typ, [data]) = <instance>.subscribe(mailbox)

        """

        return self._simple_command('SUBSCRIBE', mailbox)

    def uid(self, command, *args):

        """Execute "command arg ..." with messages identified by UID,

                rather than message number.

        (typ, [data]) = <instance>.uid(command, arg1, arg2, ...)

        Returns response appropriate to 'command'.

        """

        command = command.upper()

        if not Commands.has_key(command):

            raise self.error("Unknown IMAP4 UID command: %s" % command)

        if self.state not in Commands[command]:

            raise self.error('command %s illegal in state %s'

                                    % (command, self.state))

        name = 'UID'

        typ, dat = apply(self._simple_command, (name, command) + args)

        if command == 'SEARCH':

            name = 'SEARCH'

        else:

            name = 'FETCH'

        return self._untagged_response(typ, dat, name)

    def unsubscribe(self, mailbox):

        """Unsubscribe from old mailbox.

        (typ, [data]) = <instance>.unsubscribe(mailbox)

        """

        return self._simple_command('UNSUBSCRIBE', mailbox)

    def xatom(self, name, *args):

        """Allow simple extension commands

                notified by server in CAPABILITY response.

        (typ, [data]) = <instance>.xatom(name, arg, ...)

        """

        if name[0] != 'X' or not name in self.capabilities:

            raise self.error('unknown extension command: %s' % name)

        return apply(self._simple_command, (name,) + args)

    #       Private methods

    def _append_untagged(self, typ, dat):

        if dat is None: dat = ''

        ur = self.untagged_responses

        if __debug__:

            if self.debug >= 5:

                _mesg('untagged_responses[%s] %s += ["%s"]' %

                        (typ, len(ur.get(typ,'')), dat))

        if ur.has_key(typ):

            ur[typ].append(dat)

        else:

            ur[typ] = [dat]

    def _check_bye(self):

        bye = self.untagged_responses.get('BYE')

        if bye:

            raise self.abort(bye[-1])

    def _command(self, name, *args):

        if self.state not in Commands[name]:

            self.literal = None

            raise self.error(

            'command %s illegal in state %s' % (name, self.state))

        for typ in ('OK', 'NO', 'BAD'):

            if self.untagged_responses.has_key(typ):

                del self.untagged_responses[typ]

        if self.untagged_responses.has_key('READ-ONLY') \

        and not self.is_readonly:

            raise self.readonly('mailbox status changed to READ-ONLY')

        tag = self._new_tag()

        data = '%s %s' % (tag, name)

        for arg in args:

            if arg is None: continue

            data = '%s %s' % (data, self._checkquote(arg))

        literal = self.literal

        if literal is not None:

            self.literal = None

            if type(literal) is type(self._command):

                literator = literal

            else:

                literator = None

                data = '%s {%s}' % (data, len(literal))

        if __debug__:

            if self.debug >= 4:

                _mesg('> %s' % data)

            else:

                _log('> %s' % data)

        try:

            self.sock.send('%s%s' % (data, CRLF))

        except socket.error, val:

            raise self.abort('socket error: %s' % val)

        if literal is None:

            return tag

        while 1:

            # Wait for continuation response

            while self._get_response():

                if self.tagged_commands[tag]:   # BAD/NO?

                    return tag

            # Send literal

            if literator:

                literal = literator(self.continuation_response)

            if __debug__:

                if self.debug >= 4:

                    _mesg('write literal size %s' % len(literal))

            try:

                self.sock.send(literal)

                self.sock.send(CRLF)

            except socket.error, val:

                raise self.abort('socket error: %s' % val)

            if not literator:

                break

        return tag

    def _command_complete(self, name, tag):

        self._check_bye()

        try:

            typ, data = self._get_tagged_response(tag)

        except self.abort, val:

            raise self.abort('command: %s => %s' % (name, val))

        except self.error, val:

            raise self.error('command: %s => %s' % (name, val))

        self._check_bye()

        if typ == 'BAD':

            raise self.error('%s command error: %s %s' % (name, typ, data))

        return typ, data

    def _get_response(self):

        # Read response and store.

        #

        # Returns None for continuation responses,

        # otherwise first response line received.

        resp = self._get_line()

        # Command completion response?

        if self._match(self.tagre, resp):

            tag = self.mo.group('tag')

            if not self.tagged_commands.has_key(tag):

                raise self.abort('unexpected tagged response: %s' % resp)

            typ = self.mo.group('type')

            dat = self.mo.group('data')

            self.tagged_commands[tag] = (typ, [dat])

        else:

            dat2 = None

            # '*' (untagged) responses?

            if not self._match(Untagged_response, resp):

                if self._match(Untagged_status, resp):

                    dat2 = self.mo.group('data2')

            if self.mo is None:

                # Only other possibility is '+' (continuation) response...

                if self._match(Continuation, resp):

                    self.continuation_response = self.mo.group('data')

                    return None     # NB: indicates continuation

                raise self.abort("unexpected response: '%s'" % resp)

            typ = self.mo.group('type')

            dat = self.mo.group('data')

            if dat is None: dat = ''        # Null untagged response

            if dat2: dat = dat + ' ' + dat2

            # Is there a literal to come?

            while self._match(Literal, dat):

                # Read literal direct from connection.

                size = int(self.mo.group('size'))

                if __debug__:

                    if self.debug >= 4:

                        _mesg('read literal size %s' % size)

                data = self.file.read(size)

                # Store response with literal as tuple

                self._append_untagged(typ, (dat, data))

                # Read trailer - possibly containing another literal

                dat = self._get_line()

            self._append_untagged(typ, dat)

        # Bracketed response information?

        if typ in ('OK', 'NO', 'BAD') and self._match(Response_code, dat):

            self._append_untagged(self.mo.group('type'), self.mo.group('data'))

        if __debug__:

            if self.debug >= 1 and typ in ('NO', 'BAD', 'BYE'):

                _mesg('%s response: %s' % (typ, dat))

        return resp

    def _get_tagged_response(self, tag):

        while 1:

            result = self.tagged_commands[tag]

            if result is not None:

                del self.tagged_commands[tag]

                return result

            # Some have reported "unexpected response" exceptions.

            # Note that ignoring them here causes loops.

            # Instead, send me details of the unexpected response and

            # I'll update the code in `_get_response()'.

            try:

                self._get_response()

            except self.abort, val:

                if __debug__:

                    if self.debug >= 1:

                        print_log()

                raise

    def _get_line(self):

        line = self.file.readline()

        if not line:

            raise self.abort('socket error: EOF')

        # Protocol mandates all lines terminated by CRLF

        line = line[:-2]

        if __debug__:

            if self.debug >= 4:

                _mesg('< %s' % line)

            else:

                _log('< %s' % line)