BSD Now - Episodes Tagged with “Ntimed”

76: Time for a Change

JT Pennington — Wed, 11 Feb 2015 08:00:00 -0500

This week, we'll be talking to Henning Brauer about OpenNTPD and its recently revived portable version. After that, we'll be discussing different ways to securely tunnel your traffic: specifically OpenVPN, IPSEC, SSH and Tor. All that and the latest news, coming up on BSD Now - the place to B.. SD.

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Headlines

Strange timer bug in FreeBSD 11

Peter Wemm wrote in to the FreeBSD -CURRENT mailing list with an interesting observation
Running the latest development code in the infrastructure, the clock would stop keeping time after 24 days of uptime
This meant things like cron and sleep would break, TCP/IP wouldn't time out or resend packets, a lot of things would break
A workaround until it was fixed was to reboot every 24 days, but this is BSD we're talking about - uptime is our game
An initial proposal was adding a CFLAG to the build options which makes makes signed arithmetic wrap
Peter disagreed and gave some background, offering a different patch to fix the issue and detect it early if it happens again
Ultimately, the problem was traced back to an issue with a recent clang import
It only affected -CURRENT, not -RELEASE or -STABLE, but was definitely a bizarre bug to track down ***

An OpenBSD mail server

There's been a recent influx of blog posts about building a BSD mail server for some reason
In this fancy series of posts, the author sets up OpenSMTPD in its native OpenBSD home, whereas previous posts have been aimed at FreeBSD and Linux
In addition to the usual steps, this one also covers DKIMproxy, ClamAV for scanning attachments, Dovecot for IMAP and also multiple choices of spam filtering: spamd or SpamAssassin
It also shows you how to set up Roundcube for building a web interface, using the new in-base httpd
That means this is more of a "complete solution" - right down to what the end users see
The series is split up into categories so it's very easy to follow along step-by-step ***

How DragonFlyBSD uses git

DragonFlyBSD, along with PCBSD and EdgeBSD, uses git as its version control system for the system source code
In a series of posts, Matthew Dillon (the project lead) details their internal setup
They're using vanilla git over ssh, with the developers' accounts set to git-only (no shell access)
The maintainers of the server are the only ones with shell access available
He also details how a cron job syncs from the master to a public box that anyone can check out code from
It would be interesting to hear about how other BSD projects manage their master source repository ***

Why not try PCBSD?

ITwire, another more mainstream tech site, published a recent article about switching to PCBSD
They interview a guy named Kris that we've never heard of before
In the article, they touch on how easy it can potentially be for Linux users looking to switch over to the BSD side - lots of applications are exactly the same
"With the growing adoption of systemd, dissatisfaction with Linux has reached proportions not seen in recent years, to the extent that people have started talking of switching to FreeBSD."
If you have some friends who complain to you about systemd all the time, this might be a good article to show them ***

Interview - Henning Brauer - henning@openbsd.org / @henningbrauer

OpenNTPD and its portable variant

News Roundup

Authenticated time in OpenNTPD

We recorded that interview with Henning just a few days ago, and it looks like part of it may be outdated already
While at the hackathon, some developers came up with an alternate way to get authenticated NTP responses
You can now add an HTTPS URL to your ntpd.conf in addition to the time server pool
OpenNTPD will query it (over TLS, with CA verification) and look at the date sent in the HTTPS header
It's not intended to be a direct time source, just a constraint to keep things within reason
If you receive regular NTP packets that are way off from the TLS packet, those will be discarded and the server(s) marked as invalid
Henning and Theo also weigh in to give some of the backstory on the idea
Lots more detail can be found in Reyk's email explaining the new feature (and it's optional of course) ***

NetBSD at Open Source Conference 2015 Oita and Hamanako

It's been a while since we've featured one of these trip reports, but the Japanese NetBSD users group is still doing them
This time the conferences were in Oita and Hamanako, Japan
Machines running NetBSD included the CubieBoard2 Allwinner A20, Raspberry Pi and Banana Pi, Sharp NetWalker and a couple Zaurus devices
As always, they took lots of pictures from the event of NetBSD on all these weird machines ***

Poudriere in a jail

A common question we get about our poudriere tutorial is "how do I run it in a jail?" - this blog post is about exactly that
It takes you through the networking setup, zpool setup, nginx setup, making the jail and finally poking the right holes in the jail to allow poudriere to work its magic ***

Bruteblock, another way to stop bruteforce

We've mentioned a few different ways to stop ssh bruteforce attempts in the past: fail2ban, denyhosts, or even just with pf's built-in rate limiting
Bruteblock is a similar tool, but it's not just for ssh logins - it can do a number of other services
It can also work directly with IPFW, which is a plus if you're using that as your firewall
Add a few lines to your syslog.conf and bruteblock will get executed automatically
The rest of the article takes you through the different settings you can configure for blocking ***

New iwm(4) driver and cross-polination

The OpenBSD guys recently imported a new "iwm" driver for newer Intel 7260 wireless cards (commonly found in Thinkpads)
NetBSD wasted no time in porting it over, giving a bit of interesting backstory
According to Antti Kantee, "it was created for OpenBSD by writing and porting a NetBSD driver which was developed in a rump kernel in Linux userspace"
Both projects would appreciate further testing if you have the hardware and can provide useful bug reports
Maybe FreeBSD and DragonFly will port it over too, or come up with something that's partially based on the code ***

PCBSD current images

The first PCBSD -CURRENT images should be available this weekend
This image will be tagged 11.0-CURRENTFEB2015, with planned monthly updates
For the more adventurous this will allow testing both FreeBSD and PCBSD bleeding edge ***

Feedback/Questions

Mailing List Gold

Discussion

Comparison of ways to securely tunnel your traffic

OpenVPN, OpenBSD IKED, FreeBSD IPSEC, OpenSSH, Tor ***

70: Daemons in the North

JT Pennington — Wed, 31 Dec 2014 08:00:00 -0500

It's our last episode of 2014, and we'll be chatting with Dan Langille about the upcoming BSDCan conference. We'll find out what's planned and what sorts of presentations they're looking for. As usual, answers to viewer-submitted questions and all the week's news, coming up on BSD Now - the place to B.. SD.

This episode was brought to you by

Headlines

OpenBSD PIE enhancements

ASLR and PIE are great security features that OpenBSD has had enabled by default for a long time, in both the base system and ports, but they have one inherent problem
They only work with dynamic libraries and binaries, so if you have any static binaries, they don't get the same treatment
For example, the default shells (and many other things in /bin and /sbin) are statically linked
In the case of the static ones, you can always predict the memory layout, which is very bad and sort of defeats the whole purpose
With this and a few related commits, OpenBSD fixes this by introducing static self-relocation
More and more CPU architectures are being tested and getting support too; this isn't just for amd64 and i386 - VAX users can rest easy
It'll be available in 5.7 in May, or you can use a -current snapshot if you want to get a slice of the action now ***

FreeBSD foundation semi-annual newsletter

The FreeBSD foundation publishes a huge newsletter twice a year, detailing their funded projects and some community activities
As always, it starts with a letter from the president of the foundation - this time it's about encouraging students and new developers to get involved
The article also has a fundraising update with a list of sponsored projects, and they note that the donations meter has changed from dollars to number of donors (since they exceeded the goal already)
You can read summaries of all the BSD conferences of 2014 and see a list of upcoming ones next year too
There are also sections about the FreeBSD Journal's progress, a new staff member and a testimonial from NetApp
It's a very long report, so dedicate some time to read all the way through it
This year was pretty great for BSD: both the FreeBSD and OpenBSD foundations exceeded their goals and the NetBSD foundation came really close too
As we go into 2015, consider donating to whichever BSD you use, it really can make a difference ***

Modernizing OpenSSH fingerprints

When you connect to a server for the first time, you'll get what's called a fingerprint of the host's public key - this is used to verify that you're actually talking to the same server you intended to
Up until now, the key fingerprints have been an MD5 hash, displayed as hex
This can be problematic, especially for larger key types like RSA that give lots of wiggle room for collisions, as an attacker could generate a fake host key that gives the same MD5 string as the one you wanted to connect to
This new change replaces the default MD5 and hex with a base64-encoded SHA256 fingerprint
You can add a "FingerprintHash" line in your ssh_config to force using only the new type
There's also a new option to require users to authenticate with more than one public key, so you can really lock down login access to your servers - also useful if you're not 100% confident in any single key type
The new options should be in the upcoming 6.8 release ***

Interview - Dan Langille - info@bsdcan.org / @bsdcan

Plans for the BSDCan 2015 conference

News Roundup

Introducing ntimed, a new NTP daemon

As we've mentioned before in our tutorials, there are two main daemons for the Network Time Protocol - ISC's NTPd and OpenBSD's OpenNTPD
With all the recent security problems with ISC's NTPd, Poul-Henning Kamp has been working on a third NTP daemon
It's called "ntimed" and you can try out a preview version of it right now - it's in FreeBSD ports or on Github
PHK also has a few blog entries about the project, including status updates ***

OpenBSD-maintained projects list

There was recently a read on the misc mailing list asking about different projects started by OpenBSD developers
The initial list had marks for which software had portable versions to other operating systems (OpenSSH being the most popular example)
A developer compiled a new list from all of the replies to that thread into a nice organized webpage
Most people are only familiar with things like OpenSSH, OpenSMTPD, OpenNTPD and more recently LibreSSL, but there are quite a lot more
This page also serves as a good history lesson for BSD in general: FreeBSD and others have ported some things over, while a couple OpenBSD tools were born from forks of FreeBSD tools (mergemaster, pkg tools, portscout) ***

Monitoring network traffic with FreeBSD

If you've ever been curious about monitoring network traffic on your FreeBSD boxes, this forum post may be exactly the thing for you
It'll show you how to combine the Netflow, NfDump and NfSen suite of tools to get some pretty detailed network stats (and of course put them into a fancy webpage)
This is especially useful for finding out what was going on at a certain point in time, for example if you had a traffic spike ***

Trapping spammers with spamd

This is a blog post about OpenBSD's spamd - a spam email deferral daemon - and how to use it for your mail
It gives some background on the greylisting approach to spam, rather than just a typical host blacklist
"Greylisting is a method of defending e-mail users against spam. A mail transfer agent (MTA) using greylisting will "temporarily reject" any email from a sender it does not recognize. If the sender re-attempts mail delivery at a later time, the sender may be allowed to continue the mail delivery conversation."
The post also shows how to combine it with PF and other tools for a pretty fancy mail setup
You can find spamd in the OpenBSD base system, or use it with FreeBSD or NetBSD via ports and pkgsrc
You might also want to go back and listen to BSDTalk episode 68, where Will talks to Bob Beck about spamd ***