DuckCorp » CyborgHood

module PostmanLand

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

class Mail < Delegator

include I18nTranslation

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

@mail = TMail::Mail.parse(msg)

end

def self.blank

m = self.new

m.clear

m

end

def __getobj__

@mail

end

def process

if is_marked?

if @config.debug.flags.include?('debug_ignorereplay')

logger.warn "Debug: ignoring replay"

else

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_pretty || @mail.from_addrs_pretty).collect do |a|

TMail::Address.parse(@mail.class.header_value_smtp(a))

end

reply = self.class.new(tmail_reply.to_s)

reply.set_custom_headers

reply.user = @user

reply

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 + self.default_body_signature

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] = @mail.class.quote_address_if_necessary(@mail[h].to_s, "utf-8")

end

def default_body_signature

s = "\n" +

"-- \n" +

"#{CyborgHood::PRODUCT} v#{CyborgHood::VERSION}\n"

s += _("Contact eMail:").to_s + " \"#{@config.contact.name}\" <#{@config.contact.email}>\n" if @config.contact.email

s += _("Contact URL:").to_s + " #{@config.contact.url}\n" if @config.contact.url

s

end

def deliver

check_headers

smtp_server = @config.mail.smtp_server

smtp_port = @config.mail.smtp_port

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

def to_s

@mail.to_s

end

def crypt(fingerprint = nil)

@mail = @mail.create_encrypted(fingerprint || @user.keyFingerPrint)

end

def sign

# we don't check the uid, as there 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

def sign_and_crypt(fingerprint = nil)

# not using sign_and_crypt(), to avoid repeating code

sign()

crypt(fingerprint || @user.keyFingerPrint)

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})"

@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

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

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 = @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 = @user

# propagate message_id to be able to mark messages (replay protection)

clear_mail.message_id = @mail.message_id

decrypted_mail = clear_mail.process

# reverse propagate user information (convenience)

@user = decrypted_mail.user

return decrypted_mail

rescue GPGME::Error, NotImplementedError => e

raise CyberError.new(:unrecoverable, "protocol/mail", e.message)

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())

def is_marked?

File.exists?(mark_filename())

end