Even though SMTP (on port 25) is typically opportunistic and a MitM attack can't be prevented, we may as well only offer ciphers that provide some level of security. If a client is so old or misconfigured that it doesn't support newer ciphers, it should hopefully fall back to a non-TLS connection.
Postfix's default was basically anything goes (anonymous and 40-bit ciphers!). Google's MTA's only offer ciphers at 112 bits at greater, and this change approximates that with Postfix's "medium" setting.
Fixes#371
This disallows aNULL and other bad ciphers in the Postfix submission server.
I missed an option in 45e93f7dcc recommended by the blog post I was reading.
Fixes#389.
Prior to nsd 4.0.1-1ubuntu0.1, we had to create the nsd user before installing the nsd package.
This was our issue #25 (see 4e6037c0e1, c7e1e29d) and I reported it upstream at https://bugs.launchpad.net/ubuntu/+source/nsd/+bug/1311886. The new package was published by Ubuntu on 2015-01-15 so this work-around is no longer needed.
* use the AES256 cipher, be explicit that only the first line of secret_key.txt is used, and sanity check that the passphrase is long enough
* change overship of the encrypted files to the user-data user
* simplify variable names in management/backup.py
* although I appreciate long comments I am trimming the commentary about the backup migration
* revise the control panel template to not refer to the old unencrypted files
* add CHANGELOG entry
[Josh merged some subsequent commits:]
* Guard via idempotency against termination between migration operations
* Final corrections and tweaks
* Pass passphrase through to all duplicity calls
Empirical evidence (a failed cron job) shows that cleanup requires the
passphrase (so it presumably needs to decrypt metadata), and though
remove-older-than has been working fine without it, it won't do any harm
to set it in case that changes or there are any special cases.
* Add back the archive-dir override but locate it at STORAGE_ROOT/backup/cache
I changed my mind. In 1bf8f1991f I allowed Unicode domain names to go into the database. I thought that was nice because it's what the user *means*. But it's not how the web works. Web and DNS were working, but mail wasn't. Postfix (as shipped with Ubuntu 14.04 without support for SMTPUTF8) exists in an ASCII-only world. When it goes to the users/aliases table, it queries in ASCII (IDNA) only and had no hope of delivering mail if the domain was in full Unicode in the database. I was thinking ahead to SMTPUTF8, where we *could* put Unicode in the database (though that would prevent IDNA-encoded addressing from being deliverable) not realizing it isn't well supported yet anyway.
It's IDNA that goes on the wire in most places anyway (SMTP without SMTPUTF8 (and therefore how Postfix queries our users/aliases tables), DNS zone files, nginx config, CSR 'CN' field, X509 Common Name and Subject Alternative Names fields), so we should really be talking in terms of IDNA (i.e. ASCII).
This partially reverts commit 1bf8f1991f, where I added a lot of Unicode=>IDNA conversions when writing configuration files. Instead I'm doing Unicode=>IDNA before email addresses get into the users/aliases table. Now we assume the database uses IDNA-encoded ASCII domain names. When adding/removing aliases, addresses are converted to ASCII (w/ IDNA). User accounts must be ASCII-only anyway because of Dovecot's auth limitations, so we don't do any IDNA conversion (don't want to change the user's login info behind their back!). The aliases control panel page converts domains back to Unicode for display to be nice. The status checks converts the domains to Unicode just for the output headings.
A migration is added to convert existing aliases with Unicode domains into IDNA. Any custom DNS or web settings with Unicode may need to be changed.
Future support for SMTPUTF8 will probably need to add columns in the users/aliases table so that it lists both IDNA and Unicode forms.
CHANGELOG
=========
v0.08 (April 1, 2015)
---------------------
Mail:
* The Roundcube vacation_sieve plugin by @arodier is now installed to make it easier to set vacation auto-reply messages from within Roundcube.
* Authentication-Results headers for DMARC, added in v0.07, were mistakenly added for outbound mail --- that's now removed.
* The Trash folder is now created automatically for new mail accounts, addressing a Roundcube error.
DNS:
* Custom DNS TXT records were not always working and they can now override the default SPF, DKIM, and DMARC records.
System:
* ownCloud updated to version 8.0.2.
* Brute-force SSH and IMAP login attempts are now prevented by properly configuring fail2ban.
* Status checks are run each night and any changes from night to night are emailed to the box administrator (the first user account).
Control panel:
* The new check that system services are running mistakenly checked that the Dovecot Managesieve service is publicly accessible. Although the service binds to the public network interface we don't open the port in ufw. On some machines it seems that ufw blocks the connection from the status checks (which seems correct) and on some machines (mine) it doesn't, which is why I didn't notice the problem.
* The current backup chain will now try to predict how many days until it is deleted (always at least 3 days after the next full backup).
* The list of aliases that forward to a user are removed from the Mail Users page because when there are many alises it is slow and times-out.
* Some status check errors are turned into warnings, especially those that might not apply if External DNS is used.
* Passwords must be at least four characters. So we need to check them
here to ensure that first user creation works during initial setup
* Change quotes to match rest of code
Currently read_password does not verify password length. But further down the chain, passwords are checked to make sure they are longer than four characters.
If during initial setup, the user enters a password that is shorter than four characters, this will not be caught here, but when the script actually calls management/mailconfig.py to add the user, it will fail without a chance to correct the short password.
The setup script will then continue without an inital user being created and this will confuse users.
