def sender_verify_forward(self, mailfrom, rcpttos, msg):
""" Forwards mail to user of our service.
The criteria for forwarding to user is that there is only 1
recipient and the sender is a noreply for a supported email service;
"""
if len(rcpttos) != 1:
return
# Must be using our servername
prcpt = Address(rcpttos[0])
username = prcpt.parse_user_address()
if not username:
return
# Must be a user of our service
userdata = self.db.get_user(username=username)
if userdata == False:
return
# Now we can forward
user = User(**userdata)
logging.debug('Forwarding verification mail to service user at %s', \
user.get_forwarding_address())
self.send(mailfrom, [user.get_forwarding_address()], msg)
return
def create_alias(self, user, mailfrom, rcpttos, msg):
""" Handles Case 1b, for creating a new alias.
"""
# Use first string token as aliasname.
# The second string token can specify options.
# Current options supported:
# - UNTRUSTED
# - HINT <hint>
aliastokens = msg['Subject'].rsplit(' ')
aliasname = aliastokens[0]
isprimary = False
istrusted = True
hint = None
# TODO: This is not the most robust way to parse options,
# but will do for now.
if len(aliastokens) > 1:
for t in range(1, len(aliastokens)):
opt = aliastokens[t].lower()
if opt == 'untrusted':
istrusted = False
elif opt == 'primary':
isprimary = True
elif opt == 'hint' and t < (len(aliastokens)-1):
hint = aliastokens[t+1]
# aliasname must be properly formatted
if not alias.is_alias_name(aliasname):
logging.info('Improper aliasname format: "%s"', aliasname)
# Create error response message
err = ErrorMessage('createalias.badalias',
fromaddx = self.cfg.GETALIAS,
toaddx = user.get_account_address(),
aliasname = aliasname,
maxlen = self.cfg.MAXALIASNAMELEN)
self.send(err['From'], [user.get_forwarding_address()], err)
return
aliasaddx = self.create_alias_helper(user, aliasname, rcpt=None, \
primary=isprimary, trusted=istrusted, hint=hint)
if aliasaddx == None:
# Something went terribly wrong
return
# Create response message
msg = UserMessage('createalias.aliascreated',
fromaddx = self.cfg.GETALIAS,
toaddx = user.get_account_address(),
aliasaddx = aliasaddx)
self.send(msg['From'], [user.get_forwarding_address()], msg)
return
def create_send_alias(self, user, areq, mailfrom, rcpttos, msg):
""" Handles Case 1c, for creating a new alias and sending the message under it.
"""
aliasname = areq.parse_areq_address()
# If there are exactly two recipients, the other recipient could
# be used as a hint to create_alias_helper to search the
# history for reusable random string. If there are more than two
# recipients, create_alias_helper will just create a new random
# string.
msgtos = msg.get_header_addresses('to')
other_rcpt = None
if len(msgtos) == 2:
for t in msgtos:
if str(t) != str(areq):
other_rcpt = t
break
aliasaddx = self.create_alias_helper(user, aliasname, other_rcpt)
if aliasaddx == None:
# Something went terribly wrong
return
# Replace request address in message and envelope
msg.replace_address('to', areq, aliasaddx)
forareq = False
for r in range(len(rcpttos)):
if areq == rcpttos[r]:
forareq = True
rcpttos[r] = str(aliasaddx)
break
# Create a string that excludes areq
strmsgtos = ''
for r in range(len(msgtos)):
if not( areq == msgtos[r] ):
strmsgtos = strmsgtos + str(msgtos[r]) + '\r\n'
if forareq == True:
# Tell the user which aliasname is used.
umsg = UserMessage('createsendalias.aliascreated',
fromaddx = self.cfg.GETALIAS,
toaddx = user.get_account_address(),
aliasaddx = aliasaddx,
subject = msg['Subject'],
rcpts = strmsgtos)
self.send(umsg['From'], [user.get_forwarding_address()], umsg)
# If the mail is strictly intended for the alias request
# address, we don't need to process it further.
if len(rcpttos) == 1:
return
logging.debug('PASSTHROUGH')
self.apply_aliasing(user, mailfrom, rcpttos, msg)
return
def list_aliases(self, user, mailfrom, rcpttos, msg):
""" Returns list of previously used aliases to sender.
"""
alist = self.db.get_aliases(user.get_uid())
aliststr = '\n'.join(map(lambda x: Alias(*x).get_alias_pair(), alist))
# Create response message
umsg = UserMessage('listalias.get',
fromaddx = self.cfg.GETALIAS,
toaddx = user.get_account_address(),
subject = msg['Subject'],
aliaslist = aliststr)
self.send(msg['From'], [user.get_forwarding_address()], umsg)
return
def recv_captcha(self, mailfrom, msg):
""" Receives and verifies captcha.
"""
subject = msg['Subject']
orgidentifier = string.split(subject,' ')[-1]
logging.debug('Orig CAPTCHA identifier\t: %s', orgidentifier)
# TODO: Reject if original identifier is not in DB
try:
if msg.is_multipart():
answer = msg.get_payload(0).get_payload().splitlines()[0].strip()
else:
answer = msg.get_payload().splitlines()[0].strip()
except:
return
identifier = self.db.hash_data(Address(mailfrom).address, answer)
match = self.db.get_captcha_word(identifier)
if match != None and match['word'] == answer:
# Update captcha status to CAPTCHA_APPROVED
cid, rid, word = match
adata = self.db.get_alias_data(rid)
aobj = Alias(**adata)
user = User(**self.db.get_user(uid=aobj.get_uid()))
# send message to recipient's alias requesting mailfrom's permission to send
msg = UserMessage('senderverify.senduserreq', \
fromaddx = self.cfg.SVCALIAS, \
aliasaddx = aobj.get_alias_address(), \
useraddx = user.get_account_address(), \
requestor = mailfrom)
msg.generate_message_id(self.cfg.DOMAIN)
self.db.set_captcha(msg['Message-ID'], '', cid, rid, self.db.CAPTCHA_APPROVED)
logging.debug('Sending approval request to user %s', user.get_username())
self.send(msg['From'], [user.get_forwarding_address()], msg)
# Delete identifier from database
#self.db.delete_captcha_identifier(identifier)
else:
# TOFIX: should replace with new captcha and increment numtries;
pass
def apply_aliasing(self, user, mailfrom, rcpttos, msg):
""" Applies an alias as the sender of a message or attempts to infer
it if none was given by the sender.
Handles cases 1d and 1e of the specification.
"""
usralias = None
alias_addx = None
is_alias_address = lambda entry: entry.parse_alias_address()
logging.debug('Attempting to apply aliasing')
# look for use of existing alias in To field (case 1d);
for cur_addx in msg.search_header_addresses('to', is_alias_address):
alias_pair = cur_addx.parse_alias_address()
alias_data = self.db.get_alias_data(*alias_pair, \
uid=user.get_uid())
if not alias_data:
continue
usralias = Alias(**alias_data)
alias_addx = cur_addx
#if not usralias.is_active():
# continue
# remove alias from rcpttos and all To fields
for i in range(len(rcpttos)):
if alias_addx == rcpttos[i]:
del rcpttos[i]
break
msg.replace_address('to', alias_addx, None)
break
# if no alias in To field, try to infer the correct one (case 1e);
if not alias_addx:
logging.debug("Couldn't find alias to use in headers; " \
'attempting to infer correct alias')
alias_data = self.db.infer_alias(user.get_uid(),
msg.get_header_addresses('to'),
user.get_salt())
if not alias_data:
logging.debug('Failed to infer alias')
err = ErrorMessage('applyalias.noinfer',
fromaddx = self.cfg.SVCALIAS,
toaddx = user.get_account_address(),
subject = msg['Subject'])
self.send(err['From'], [user.get_forwarding_address()], err)
return False
usralias = Alias(**alias_data)
#if not usralias.is_active():
# return False
logging.debug('Succesfully inferred alias "%s"', str(usralias))
alias_addx = Address(usralias.get_alias_address())
# if we found an alias to use, apply it, send the
# message, and record in history table;
alias_addx.realname = Address(mailfrom).realname
msg.replace_address('from', None, alias_addx)
#del msg['message-id']
if rcpttos == []:
logging.info('No recipients left; ignoring');
return
rcpt_aliases = []
rcpt_nonaliases = []
for entry in rcpttos:
rcpt_addx = Address(entry)
if rcpt_addx.is_servername():
rcpt_aliases.append(entry)
else:
rcpt_nonaliases.append(entry)
self.send(str(alias_addx), rcpt_nonaliases, msg)
self.forward(str(alias_addx), rcpt_aliases, msg)
self.db.add_history(usralias.get_rid(),
True,
address.getaddresses(rcpttos),
msg['Message-ID'],
user.get_salt())
return
def forward(self, mailfrom, rcpttos, msg):
""" Handles Case 2, where email is not from a service user and so
needs to be forwarded to various aliases.
"""
for rcpt in rcpttos:
prcpt = Address(rcpt)
alias_pair = prcpt.parse_alias_address()
logging.debug(rcpt)
if not alias_pair:
# if the domain is SERVERNAME, sender screwed up; return error to sender...
if prcpt.is_servername():
logging.info('Encountered improperly formatted '
'address "%s" in recipients field', prcpt.address)
# Create error response message
err = ErrorMessage('forward.badformat',
fromaddx = self.cfg.SVCALIAS,
toaddx = mailfrom,
badalias = prcpt.address)
self.send(err['From'], [mailfrom], err)
# ... otherwise ignore; not our job to send to non-users
logging.info('Encountered recipient outside our domain; ignoring')
else:
alias_data = self.db.get_alias_data(*alias_pair)
if alias_data:
fwd_alias = Alias(**alias_data)
userdata = self.db.get_user(uid=fwd_alias.get_uid())
assert userdata is not None
user = User(**userdata)
logging.debug('is trusted? %s', fwd_alias.is_trusted())
# handle trustedness here;
if not fwd_alias.is_trusted():
mfrom = Address(mailfrom)
# if sender is in trusted group, then it's all right;
if self.db.is_trusted_correspondent(mfrom, \
user.get_salt(), \
fwd_alias.get_rid(), \
fwd_alias.get_trusted_timestamp()):
pass # TODO: send/append something about newer alias to send to?
else:
capstat = self.db.get_capstat(mfrom, \
user.get_salt(), \
fwd_alias.get_rid())
logging.debug('capstat=%s', capstat)
if capstat < self.db.CAPTCHA_PENDING:
logging.debug('captcha not yet sent; trying to send one')
# If not approved, send captcha to sender and drop mail.
# TODO: Perhaps we can cache the mail somewhere.
cid = self.db.get_cid(mfrom, user.get_salt())
self.send_captcha(mailfrom, cid, fwd_alias)
#self.db.set_capstat(cid,
# fwd_alias.get_rid(),
# self.db.CAPTCHA_PENDING)
logging.debug('done sending captcha')
elif capstat == self.db.CAPTCHA_PENDING:
logging.debug('captcha was already sent; still waiting for solution')
elif capstat == self.db.CAPTCHA_APPROVED:
logging.debug('captcha approved, but not yet user approved')
# if user denied,
# TODO: just ignore? or do something more?
# pass
# if user judgement pending, send message
# informing them they must wait for user's approval?
if capstat == self.db.USER_PENDING:
pass # TODO: send message
return
# TODO: can consult a whitelist/blacklist/etc. here
fwd_addx = Address(user.get_forwarding_address())
fwd_addx.realname = prcpt.realname
logging.info('Found alias for account (%s) Forwarding message to %s', \
user.get_username(), fwd_addx.address)
# Add hint as recipient name. The hint/domain is used as a reminder
# to the user where this email address was originally created for.
# But since we did not update Reply-To, it will drop off when the
# user replies to the message.
rcptaddr = Address(rcpt)
if rcptaddr.get_realname() == '':
if fwd_alias.get_hint() != None:
rcptaddr.set_realname(fwd_alias.get_hint())
elif fwd_alias.get_domain() != None:
rcptaddr.set_realname(fwd_alias.get_domain())
msg.replace_address('To', rcpt, rcptaddr)
acct_addx = Address(user.get_account_address())
acct_addx.realname = prcpt.realname
#del msg['message-id']
#del msg['DKIM-Signature']
if 'To' in msg:
msg.replace_header('To', msg['To'] + ', ' + str(acct_addx))
if 'Reply-To' in msg:
msg.replace_header('Reply-To', msg['reply-to'] + ', ' + rcpt);
else:
msg.add_header('Reply-To', mailfrom + ', ' + rcpt);
if 'Message-ID' not in msg:
msg.generate_message_id(self.cfg.DOMAIN)
self.send(mailfrom, [str(fwd_addx)], msg)
self.db.add_history(fwd_alias.get_rid(), False, [Address(mailfrom)], msg['Message-ID'], user.get_salt())
else:
logging.info("Couldn't find data for alias (%s,%d)", *alias_pair)
return
def create_alias_helper(self, user, aliasname, \
primary=False, rcpt=None, trusted=True, hint=None):
""" Helper function to create alias.
Generates <rand> for user for the <aliasname> specified.
If <aliasname> belonging to the user already exists, the existing aid is used.
If <aliasname> belonging to another user already exists, an error is returned.
"""
(aid, uid) = self.db.get_aliasname_data(aliasname)
# Error if user doesn't own the aliasname
if uid != None and uid != user.get_uid():
logging.info('User %d does not own "%s".', user.get_uid(), aliasname)
# Create error response message
err = ErrorMessage('createalias.notowner',
fromaddx = self.cfg.GETALIAS,
toaddx = user.get_account_address(),
aliasname = aliasname)
self.send(err['From'], [user.get_forwarding_address()], err)
return None
#
# Now, aliasname either belongs to the user or is not in use.
#
# Gets the alias id, either by getting an existing one or create a new one.
if uid == user.get_uid():
newaid = aid
logging.debug('Using existing aid %d for aliasname "%s"', \
newaid, aliasname)
elif uid == None:
newaid = self.db.insert_alias(user.get_uid(), aliasname, primary)
logging.debug('Created new aid %d for aliasname "%s"', \
newaid, aliasname)
else:
return None
#
# If a recipient is given, check history to see if there was any
# previously generated <rand> that we can use.
# TODO: We might have to make sure the recipient is active.
#
newalias = None
cid = None
if rcpt != None:
cid = self.db.peek_cid(rcpt, user.get_salt())
rid = None
if cid != None:
rid = self.db.get_history_rid(aliasname, cid)
if rid != None:
# Found a history correspondence
hist_alias = Alias(self.db.get_alias_data(rid))
hist_aliasname, hist_aliasrand = hist_alias.get_alias_pair()
logging.debug('History aliasname\t:"%s"', hist_aliasname)
if hist_aliasname == aliasname:
logging.debug('Reuse history aliasrand\t:"%s"', \
hist_aliasrand)
newalias = Alias(hist_aliasname, hist_aliasrand)
else:
# Can't use the rid found since aliasname differs
rid = None
# Create a new alias (aka aliasrand or <aliasname>.<rand>)
if newalias == None:
logging.debug('Generating new aliasrand')
newalias = Alias(aliasname, alias.generate_rint())
logging.debug('Using alias\t\t: %s', newalias)
# Update aid, uid and set isactive for new alias
newalias.set_values(aid=newaid, uid=user.get_uid(), isactive=1)
# Sets up alias pair
alias_pair = newalias.get_alias_pair()
# If we don't have rid yet, insert aliasrand to DB and mark as active
if rid == None:
rid = self.db.insert_aliasrnd(user.get_uid(), \
newaid, \
alias_pair[0], alias_pair[1], \
1, trusted, hint)
if rid == None:
return None
# Looks like this double counts in the history table;
#if rcpt != None:
# self.db.add_history(rid, True, [rcpt], user.get_salt())
# Creates the alias address, which includes the domain
aliasaddx = Address(newalias.get_alias_address())
logging.info('Aliasrnd Address\t\t: %s', str(aliasaddx))
return aliasaddx