|
#--
|
|
# CyborgHood, a distributed system management software.
|
|
# Copyright (c) 2009-2010 Marc Dequènes (Duck) <Duck@DuckCorp.org>
|
|
#
|
|
# This program is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
#++
|
|
|
|
# add Rails load path for Debian, until rails framework is split properly
|
|
DEB_RAILS_PATH = "/usr/share/rails" unless Object.constants.include?("DEB_RAILS_PATH")
|
|
Dir.new(DEB_RAILS_PATH).each do |file|
|
|
next if file =~ /^\./
|
|
path = File.join(DEB_RAILS_PATH, file, "lib")
|
|
$: << path if File.directory?(path)
|
|
end
|
|
|
|
require 'delegate'
|
|
require 'tmail'
|
|
require 'tmail_gpg'
|
|
require 'action_mailer/quoting'
|
|
require 'action_mailer/utils'
|
|
require 'net/smtp'
|
|
require 'fileutils'
|
|
require 'digest/md5'
|
|
|
|
|
|
# This class handles RFC3156 signed/encrypted messages, validates them, and extract content properly.
|
|
# It also implements a protection against replay attacks.
|
|
module CyborgHood
|
|
class MailReport
|
|
attr_reader :error, :warn_sender, :user, :message
|
|
|
|
def initialize(params = {})
|
|
@error = params[:error]
|
|
@warn_sender = params[:warn_sender]
|
|
@user = params[:user]
|
|
@message = params[:message]
|
|
|
|
@warn_sender = false
|
|
end
|
|
|
|
def ok?
|
|
@error.nil? and @user and @message
|
|
end
|
|
|
|
def warn_sender
|
|
# send reply message if user is identified or in selected situations
|
|
# (@warn_sender acts as an override)
|
|
@warn_sender || @user
|
|
end
|
|
end
|
|
|
|
class Mail < Delegator
|
|
include ActionMailer::Quoting
|
|
include ActionMailer::Utils
|
|
include I18nTranslation
|
|
|
|
DEFAULT_MAX_DRIFT_TIME = 3600
|
|
|
|
attr_accessor :user, :signature_timestamp
|
|
|
|
def initialize(msg = nil)
|
|
@config = Config.instance
|
|
|
|
if msg.nil?
|
|
@mail = TMail::Mail.new
|
|
set_custom_headers
|
|
elsif msg.is_a? TMail::Mail
|
|
@mail = msg
|
|
else
|
|
# unquote headers and transform into TMail object
|
|
@mail = TMail::Mail.parse(msg)
|
|
end
|
|
end
|
|
|
|
def self.blank
|
|
m = self.new
|
|
m.clear
|
|
m
|
|
end
|
|
|
|
def __getobj__
|
|
@mail
|
|
end
|
|
|
|
def self.header_value_pretty(v)
|
|
TMail::Unquoter.unquote_and_convert_to(v.to_s, "UTF-8")
|
|
end
|
|
|
|
def self.header_value_smtp(v)
|
|
quote_address_if_necessary(v, "UTF-8")
|
|
end
|
|
|
|
["from", "to", "cc", "bcc"].each do |h|
|
|
class_eval <<-EOF
|
|
def #{h}_addrs_pretty
|
|
@mail.#{h}_addrs.collect do |a|
|
|
self.class.header_value_pretty(a)
|
|
end
|
|
end
|
|
|
|
def #{h}_pretty
|
|
self.#{h}_addrs_pretty.join(", ")
|
|
end
|
|
EOF
|
|
end
|
|
|
|
def subject_pretty
|
|
self.class.header_value_pretty(self.subject)
|
|
end
|
|
|
|
def process
|
|
if is_marked?
|
|
return MailReport.new(:error => _("Replay detected."))
|
|
end
|
|
|
|
return process_signed() if is_pgp_signed?
|
|
return process_encrypted() if is_pgp_encrypted?
|
|
|
|
MailReport.new(:error => _("Mail not RFC3156 compliant."))
|
|
end
|
|
|
|
def create_reply
|
|
tmail_reply = @mail.create_reply
|
|
tmail_reply.from_addrs = TMail::Address.parse(@config.mail.from_address || self.to.first)
|
|
tmail_reply.to_addrs = (@mail.reply_to_addrs || @mail.from_addrs).collect do |a|
|
|
address = TMail::Unquoter.unquote_and_convert_to(a.to_s, "UTF-8")
|
|
quoted_address = quote_address_if_necessary(address, "UTF-8")
|
|
TMail::Address.parse(quoted_address)
|
|
end
|
|
reply = self.class.new(tmail_reply.to_s)
|
|
reply.set_custom_headers
|
|
reply.user = self.user
|
|
reply
|
|
end
|
|
|
|
def create_simple_reject_reply(msg)
|
|
reply = create_reply()
|
|
reply.set_content_type("text", "plain", {'charset' => "utf-8"})
|
|
reply.set_disposition("inline")
|
|
reply.quoted_printable_body = msg
|
|
reply.sign
|
|
reply.crypt(reply.user.keyFingerPrint) unless reply.user.nil?
|
|
reply
|
|
end
|
|
|
|
def to_multipart!
|
|
self.set_content_type("multipart", "mixed", {'boundary' => TMail.new_boundary})
|
|
self.transfer_encoding = "7bit"
|
|
self.quoted_body = "This mail is in MIME format.\n"
|
|
self.parts.clear
|
|
end
|
|
|
|
def set_custom_headers
|
|
@mail['Organization'] = @config.mail.organization
|
|
end
|
|
|
|
def check_headers
|
|
@mail.header.keys.each do |h|
|
|
@mail[h] = quote_address_if_necessary(@mail[h].to_s, "utf-8")
|
|
end
|
|
end
|
|
|
|
def deliver
|
|
check_headers
|
|
|
|
smtp_server = @config.mail.smtp_server || "localhost"
|
|
smtp_port = @config.mail.smtp_port || 25
|
|
smtp_from = @mail.from_addrs.collect{|a| a.address}.join(", ")
|
|
smtp_to = @mail.to_addrs.collect{|a| a.address}
|
|
Net::SMTP.start(smtp_server, smtp_port) do |smtp|
|
|
smtp.send_message(@mail.to_s, smtp_from, smtp_to)
|
|
end
|
|
end
|
|
|
|
def to_s
|
|
@mail.to_s
|
|
end
|
|
|
|
def crypt(fingerprint)
|
|
@mail = @mail.create_encrypted(fingerprint)
|
|
end
|
|
|
|
def sign
|
|
# we don't check the uid, as their is only one signer
|
|
@mail = @mail.create_signed(@config.mail.key_id) do |uid_hint, passphrase_info, prev_was_bad|
|
|
@config.mail.key_passphrase
|
|
end
|
|
end
|
|
|
|
def sign_and_crypt(fingerprint)
|
|
# not using sign_and_crypt(), to avoid repeating code
|
|
sign()
|
|
crypt(fingerprint)
|
|
end
|
|
|
|
def quoted_printable_body=(txt)
|
|
@mail.transfer_encoding = "quoted-printable"
|
|
@mail.body = [normalize_new_lines(txt)].pack("M")
|
|
end
|
|
|
|
private
|
|
|
|
def process_signed
|
|
sigs_check = verify_pgp_signature()
|
|
return MailReport.new(:error => _("Mail not formatted correctly (signed part).")) if sigs_check.nil? or sigs_check.size != 1
|
|
|
|
sig_check = sigs_check.first
|
|
return MailReport.new(:error => _("Mail content tampered or badly signed: %{sig_err}", :sig_err => sig_check.to_s)) unless sig_check.status == 0
|
|
|
|
logger.info "Mail content was properly signed by key #{sig_check.fingerprint}"
|
|
user = Person.find_by_fingerprint(sig_check.fingerprint)
|
|
return MailReport.new(:error => _("Mail is from an unknown person."), :warn_sender => true) if user.nil?
|
|
|
|
logger.info "Mail is from user #{user.uid} (#{user.cn})"
|
|
self.user = user
|
|
|
|
drift = Time.new.to_i - sig_check.timestamp.to_i
|
|
logger.debug "Signature drift time: #{drift}"
|
|
unless drift.abs < (@config.mail.max_drift_time || DEFAULT_MAX_DRIFT_TIME)
|
|
if drift > 0
|
|
return MailReport.new(:error => _("The signature was made too long ago (check your system clock). Rejected message to avoid replay attacks."), :user => user)
|
|
else
|
|
# mark message to prevent later replay of the message
|
|
mark_processed(sig_check.timestamp)
|
|
return MailReport.new(:error => _("The signature was made in the future (check your system clock). Rejected message to avoid replay attacks."), :user => user)
|
|
end
|
|
end
|
|
|
|
logger.debug "Mail OK"
|
|
mark_processed(self.signature_timestamp)
|
|
|
|
signed_content = pgp_signed_part()
|
|
|
|
# create a fake mail and chain parsing operations
|
|
plain_mail = self.class.new(signed_content)
|
|
plain_mail.user = self.user
|
|
plain_mail.signature_timestamp = sig_check.timestamp
|
|
# propagate message_id to be able to mark messages (replay protection)
|
|
plain_mail.message_id = @mail.message_id
|
|
|
|
MailReport.new(:user => user, :message => plain_mail)
|
|
end
|
|
|
|
def process_encrypted
|
|
catch :notforme do
|
|
begin
|
|
# block is not passed to delegate (limitation ?)
|
|
clear_message = @mail.pgp_decrypt do |uid_hint, passphrase_info, prev_was_bad|
|
|
logger.info "Mail crypted for #{uid_hint}"
|
|
|
|
# check if requesting passphrase for the expected key
|
|
key_id = passphrase_info.split(" ")[1]
|
|
throw :notforme if key_id != @config.mail.key_id[-(key_id.size)..-1]
|
|
|
|
# sending key
|
|
@config.mail.key_passphrase
|
|
end
|
|
|
|
# create a fake mail and chain parsing operations
|
|
clear_mail = self.class.new(clear_message)
|
|
clear_mail.user = self.user
|
|
# propagate message_id to be able to mark messages (replay protection)
|
|
clear_mail.message_id = @mail.message_id
|
|
return clear_mail.process
|
|
rescue GPGME::Error, NotImplementedError => e
|
|
raise CyberError.new(:unrecoverable, "protocol/mail", e.message)
|
|
end
|
|
end
|
|
|
|
MailReport.new(:error => _("Mail not formatted correctly (encrypted part)."))
|
|
end
|
|
|
|
def mark_dir
|
|
File.join(Config::VAR_DIR, "marks")
|
|
end
|
|
|
|
def mark_filename
|
|
File.join(mark_dir(), Digest::MD5.hexdigest(self.message_id))
|
|
end
|
|
|
|
def mark_processed(time)
|
|
FileUtils.mkdir_p(mark_dir())
|
|
File.open(mark_filename(), "w") do |fp|
|
|
fp.write self.message_id
|
|
end
|
|
File.utime(Time.now.to_i, time.to_i, mark_filename())
|
|
end
|
|
|
|
def is_marked?
|
|
File.exists?(mark_filename())
|
|
end
|
|
end
|
|
end
|