c0d3 :: j0rg3

A collection of tips, tricks and snips. A proud Blosxom weblog. All code. No cruft.

Tue, 07 Mar 2017

Privacy Part II: VPN/IPVanish - Install IPVanish on Kali Linux

Okay, so you’re running Whonix, Tails or, at least, TorBrowser.

What’s next? You may wish to consider using a VPN. In simple terms, it’s somewhat similar to what Tor offers. That is: you connect to the VPN and your connection passes through them such that the site that you are visiting will see the VPN’s IP address rather than yours. Of course, that means that you can chain them.

That is: (You)->VPN->Tor->Exit node->Web site

The reason that you might feel compelled to take this step is that a party which is able to see your traffic into and out of Tor could still identify you. The thinking is that the parties who wish to interfere with your privacy could be compelled to run Tor bridges, relays and exit nodes. If traffic from your IP address could be matched to requests coming from the Tor exit node then you could, effectively, be identified.

Some people hold that using a VPN to access Tor does not improve your anonymousness. I am not among them. In particular, you will find that IPVanish offers VPN service for under $7 per month and is popular among users of the Tor network. Which means that in addition to the fact that IPVanish is not logging your traffic, there’s an excellent chance that other users are going from IPVanish into Tor, helping to reduce the uniqueness of your traffic.

By the way, I’d suggest poking around the web a little bit. While their prices are already great you can find some even deeper discounts: https://signup.ipvanish.com/?aff=vpnfan-promo

IPVanish’s site offers instructions for installing the VPN in Ubuntu so we’re going to take a look at using IPVanish in Kali — including an interesting and unanticipated snag (and, of course, how to fix it).

Let’s grab the OpenVPN configuration:
wget http://www.ipvanish.com/software/configs/ca.ipvanish.com.crt; wget http://www.ipvanish.com/software/configs/ipvanish-US-New-York-nyc-a01.ovpn

We will need the OpenVPN package for Gnome:
apt install network-manager-openvpn-gnome

Click on the tray in the upper right corner, then the wrench/screwdriver icon:

Select the ‘Network’ folder icon:

We’re choosing ‘Wired’ (even though we’re using wlan0 interface):

We’re setting up a VPN, of course:

Import from file:

Choose the configuration file that we downloaded previously:

Enter ‘User name’ and ‘Password’:

We are connected!

Verified at IPVanish’s site: https://www.ipvanish.com/checkIP.php

And this is where I had anticipated the installation instructions would end.

I just wanted to check a few more things. And I would love to tell you that it was simply my thoroughness and unbridled CLI-fu that led to discover that I was still making ipv6 connections outside of the VPN. Seems that it wasn’t noticed by the test at IPVanish because they deal only in ipv4. I was able to prove my ipv6 address and geolocation by using: http://whatismyipaddress.com/

Further, we can establish that the test at IPVanish is not ipv6-compatible with a quick test.

The easy fix here is to disable ipv6 locally. It is plausible that this could cause unintended consequences and, to be thorough, it would be best to handle your VPN at the firewall. Having support for OpenVPN, you’ll be able to get this running with a huge variety of routing/firewall solutions. You can grab any number of tiny computers and build a professional-quality firewall solution with something like pfSense. Maybe we’ll take a look at getting that configured in a future post.

But, for now, let’s shut down ipv6 in a way that doesn’t involve any grandiose hand-waving magic (i.e., unexplained commands which probably should work) and then test to get confidence in our results.

Let’s use sysctl to find our ipv6 kernel bits and turn them off. Then we’ll load our configuration changes. As a safety, it wouldn’t be a bad idea to look in /etc/sysctl.conf to verify that there aren’t any ipv6 configs in there.

We’ll back up our config file then turn off everything ipv6 by listing everything with the words ‘ipv6’ and ‘disable’:
cp /etc/sysctl.conf /etc/$(date +%Y-%m-%d.%H-%M-%S).sysctl.conf.bak && \
sysctl -a | grep -i ipv6 | grep disable | sed 's/0/1/g' >> /etc/sysctl.conf && \
sysctl -p

To explain what we’re doing:
List all kernel flags; show uonly those containing the string ‘ipv6’; of those that remain, show only those that contain the string ‘disable’:
sysctl -a | grep -i ipv6 | grep disable
Replace the 0 values with 1, to turn ON the disabling, by piping output to:
sed 's/0/1/g'
That all gets stuck on the end of ‘sysctl.conf’ by redirecting stdout to append to the end of that file:
>> /etc/sysctl.conf
Then we reload with:
sysctl -p

Then as a final sanity-check we’ll make sure we can’t find any ipv6 packets sneaking about:
tcpdump -t -n -i wlan0 -s 256 -vv ip6

At this point, assuming our tcpdump doesn’t show any traffic, we should be ipv6-free with all of our ipv4 traffic shipped-off nicely through IPVanish!


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Permalink: 20170307.privacy.vpn.ipvanish

Sat, 04 Mar 2017

Official(ish) deep dark onion code::j0rg3 mirror

Recently I decided that I wanted my blog to be available inside of the Deep, Dark Onion (Tor).

First time around, I set up a proxy that I modified to access only the clear web version of the blog and to avail that inside Tor as a ‘hidden service’.

My blog is hosted on equipment provided by the kind folk at insomnia247.nl and I found that, within a week or so, the address of my proxy was blocked. It’s safe for us to assume that it was simply because of the outrageous popularity it received inside Tor.

By “safe for us to assume” I mean that it is highly probable that no significant harm would come from making that assumption. It would not be a correct assumption, though.

What’s more true is that within Tor things are pretty durn anonymous. Your logs will show Tor traffic coming from 127.0.0.1 only. This is a great situation for parties that would like to scan sites repeatedly looking for vulnerabilities — because you can’t block them. They can scan your site over and over and over. And the more features you have (e.g., comments, searches, any form of user input), the more attack vectors are plausible.

So why not scan endlessly? They do. Every minute of every hour.

Since insomnia247 is a provider of free shells, it is incredibly reasonable that they don’t want to take the hit for that volume of traffic. They’re providing this service to untold numbers of other users, blogs and projects.

For that reason, I decided to set up a dedicated mirror.

Works like this: my blog lives here. I have a machine at home which uses rsync to make a local copy of this blog. Immediately thereafter it rsyncs any newly gotten data up to the mirror in onionland.

After consideration, I realized that this was also a better choice just in case there is something exploitable in my blog. Instead of even risking the possibility that an attacker could get access to insomnia247, they can only get to my completely disposable VPS which has hardly anything on it except this blog and a few scripts to which I’ve already opened the source code.

I’ve not finished combing through but I’ve taken efforts to ensure it doesn’t link back to clear web. To be clear, there’s nothing inherently wrong with that. Tor users will only appear as the IP address of their exit node and should still remain anonymous. To me, it’s just onion etiquette. You let the end-user decide when they want to step outside.

To that end, the Tor mirror does not have the buttons to share to Facebook, Twitter, LinkedIn, Google Plus.

That being said, if you’re a lurker of those Internet back-alleys then you can find the mirror at: http://aacnshdurq6ihmcs.onion

Happy hacking, friends!


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Permalink: 20170304.deep.dark.onion

Sun, 19 Feb 2017

Privacy: perspective and primer.

Hello friends.

While the overall telos of this blog is to, generally speaking, convey code snippets and inspire the personal projects of others, today we’re going to do something a smidgeon different.

This will be a layman’s look at varied dimensions of information security from a comfortable distance. Over the years, I’ve secured servers, operating systems, medical data, networks, communications and I’ve unsecured many of these same things. The topics are too sprawling to be covered in a quick summary — but let’s find a point of entry.

Those of us who are passionate about information security are well aware of how daunting is the situation. For newcomers, it sometimes seems rather impossible. Pick any subject and there are probably well-informed and convincing experts in diametric equidistance from any “happy medium”.

Let’s imagine that (like most of us) you don’t have anything spectacular to protect. However, you dislike the idea of our ever-dissolving privacy. Therefore you want to encrypt communications. Maybe you begin to use Signal. However, there are criticisms that there is a “backdoor” (there is not). Further, there are accusations that open source projects are coded by those who can’t get real jobs. Conversely, open source projects are widely open for peer review. If it worries one enough they are free to review code themselves.

PGP can encrypt content but concerns surround algorithmic selections. Some are worried about metadata crumbs. Of course, there’s nothing preventing the frequent switching of keys and email addresses. You could use BitMessage, any number of chat solutions or drop at paste bins.

Let’s leave those concerns aside for when you’ve figured out what you’re intending to protect. These arguments surround any subject in information security and we’re not going to investigate them on a case by case basis. Least, not in this post.

At the coarsest granularity, the question is analogous to the practicality of locking your doors or sealing your post envelopes. Should I take measures toward privacy?

My opinion is rather predictable: of course you should!

There’s a very pragmatic explanation. If there ever comes a day when you should like to communicate privately, that’s a terrible time to start learning.

Take the easy road and start using some of the myriad tools and services available.

Should you decide to take InfoSec seriously, you’ll need to define a threat model.
That is: What am I protecting? From whom am I protecting? (e.g. what are probable attack vectors?)

That’s where you need to make choices about trusting products, protocols, methods, algorithms, companies, servers, et cet. Those are all exciting subjects to explore but all too often brushing up against them can be exasperating and cause premature burn-out.

That in mind, let’s employ the philosophy that any effort toward security is better than none and take a look at a few points where one might get wetted-toes.

If you have questions or want specific advice, there are several ways below to initiate a secure conversation with me.

 

Secure your browser:

  • Privacy Badger: Block tracking
  • HTTPS Everywhere: Increase your encryptioning
  • uBlock: Advertisements are for others
  •  

    Secure communications:

  • Mailvelope: PGP email encryption for your major webmail provider (e.g., Gmail) | contact | pubkey
  • Tutanota: Encrypted webmail | Kontakt
  • Protonmail: Well-established provider of PGP encrypted webmail, featuring 2FA | kontakta
  • BitMessage: P2P encrypted communications protocol | contact: BM-2D9tDkYEJSTnEkGDKf7xYA5rUj2ihETxVR | Bitmessage channel list
  •   [ Bitmessage in a Docker container ]

  • BitMessage.ch: BitMessage email gateway | contact
  • BitMsg.me: Online BitMessage service
  • Keybase.io: Keybase maps your identity to your public keys, and vice versa
  • Signal: PGP encrypted TXT messages
  • Wire: Encrypted chat, video and calls
  • RIOT: Open-source, IRC-based, Matrix; run your own server
  • Wickr: Encrypted ephemeral chat
  •   [ n.b. Wickr’s .deb package seeks a unicode library (libicu52) which is not available to a recent Kali (or anything) install; .deb file is based on Ubuntu’s 2014 LTS release. Wickr in a Docker container ]

     

    Explore alternate nets (e.g., Deep Web, Dark Net):

  • MaidSafe: Promising new alt-web project
  • Qubes: a reasonably secure operating system
  • FreeNet: Alt-net based primarily on already knowing with whom you intend to collaborate
  • Bitmask: VPN solution to anonymize your traffic
  • TAILS: A live operating system based on the Tor network
  • TorBrowser: Stand-alone browser for Tor (less secure than TAILS)
  • Whonix: the most secure (and complex) way to access the Tor network
  • i2p: an other approach to creating a secure and private alternate web
  • Morph.is: fun alt-net, aimed at producing The World Brain. Although, it’s future looks a lot less promising since the lead dev was killed.
  • ZeroNet: one more encrypted anonymous net
  • Have fun and compute safely!


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    Permalink: 20170219.privacy.prespective.primer

    Fri, 17 Feb 2017

    The making of a Docker: Part I - Bitmessage GUI with SSH X forwarding

    Lately, I’ve been doing a lot of work from a laptop running Kali. Engaged in pursuit of a new job, I’m brushing up on some old tools and skills, exploring some bits that have changed.

    My primary desktop rig is currently running Arch because I love the fine grain control and the aggressive releases. Over the years, I’ve Gentoo’d and Slacked, Crunchbanged, BSD’d, Solarised, et cet. And I’ve a fondness for all of them, especially the security-minded focus of OpenBSD. But, these days we’re usually on Arch or Kali. Initially, I went with Black Arch on the laptop but I felt the things and ways I was fixing things were too specific to my situation to be good material for posts.

    Anyway, I wanted to get Bitmessage running, corresponding to another post I have in drafts. On Kali, it wasn’t going well so I put it on the Arch box and just ran it over the network. A reasonable solution if you’re in my house but also the sort of solution that will keep a hacker up at night.

    If you’re lucky, there’s someone maintaining a package for the piece of software that you want to run. However, that’s often not the case.

    If I correctly recall, to “fix” the problem with Bitmessage on Kali would’ve required the manual installation an older version of libraries that were already present. Those libraries should, in fact, be all ebony and ivory, living together in harmony. However, I just didn’t love the idea of that solution. I wanted to find an approach that would be useful on a broader scale.

    Enter containerization/virtualization!

    Wanting the lightest solution, I quickly went to Docker and realized something. I have not before built a Docker container for a GUI application. And Bitmessage’s CLI/daemon mode doesn’t provide the fluid UX that I wanted. Well, the easy way to get a GUI out of a Docker container is to forward DISPLAY as an evironment variable (i.e., docker run -e DISPLAY=$DISPLAY). Splendid!

    Except that it doesn’t work on current Kali which is using QT4. There’s a when graphical apps are run as root and though it is fixed in QT5, we are using current Kali. And that means we are, by default, uid 0 and QT4.

    I saw a bunch of workarounds that seemed to have spotty (at best) rates of success including seting QT’s graphics system to Native and giving Xorg over to root. They, mostly, seemed to be cargo cult solutions.

    What made the most sense to my (generally questionable) mind was to use X forwarding. Since I had already been running Bitmessage over X forwarding from my Arch box, I knew it should work just the same.

    To be completely truthful, the first pass I took at this was with Vagrant mostly because it’s SO easy. Bring up your Vagrant Box and then:
    vagrant ssh -- -X
    Viola!

    Having proof of concept, I wanted a Docker container. The reason for this is practical. Vagrant, while completely awesome, has substantially more overhead than Docker by virtualizing the kernel. We don’t want a separate kernel running for each application. Therefore Docker is the better choice for this project.

    Also, we want this whole thing to be seemless. We want to run the command bitmessage and it should fire up with minimal awkwardness and hopefully no extra steps. That is we do not want to run the Docker container then SSH into it and execute Bitmessage as individual steps. Even though that’s going to be how we begin.

    The Bitmessage wiki accurately describes how to install the software so we’ll focus on the SSH setup. Though when we build the Dockerfile we will need to add SSH to the list from the wiki.

    We’re going to want the container to start so that the SSH daemon is ready. Until then we can’t SSH (with X forwarding) into the container. Then we’ll want to use SSH to kick off the Bitmessage application, drawing the graphical interface using our host system’s X11.

    We’re going to take advantage of Docker’s -v --volume option which allows us to specify a directory on our host system to be mounted inside our container. Using this feature, we’ll generate our SSH keys on the host and make them automatically available inside the container. We’ll tuck the keys inside the directory that Bitmessage uses for storing its configuration and data. That way Bitmessage’s configuration and stored messages can be persistent between runs — and all of your pieces are kept in a single place.

    When we generate the container /etc/ssh/sshd_config is configured to allow root login without password only (i.e., using keys). So here’s how we’ll get this done:
    mkdir -p ~/.config/PyBitmessage/keys #Ensure that our data directories exist
    cd ~/.config/PyBitmessage/keys
    ssh-keygen -b 4096 -P "" -C $"$(whoami)@$(hostname)-$(date -I)" -f docker-bitmessage-keys #Generate our SSH keys
    ln -fs docker-bitmessage-keys.pub authorized_keys #for container to see pubkey

    Build our container (sources available at Github and Docker) and we’ll make the script to handle Bitmessage to our preferences. #!/bin/bash
    # filename: bitmessage
    set -euxo pipefail

    # open Docker container:
    # port 8444 available, sharing local directories for SSH and Bitmessage data
    # detatched, interactive, pseudo-tty (-dit)
    # record container ID in $DID (Docker ID)
    DID=$(docker run -p 8444:8444 -v ~/.config/PyBitmessage/:/root/.config/PyBitmessage -v ~/.config/PyBitmessage/keys/:/root/.ssh/ -dit j0rg3/bitmessage-gui bash)

    # find IP address of new container, record in $DIP (Docker IP)
    DIP=$(docker inspect $DID | grep IPAddress | cut -d '"' -f 4)

    # pause for one second to allow container's SSHD to come online
    sleep 1

    # SSH into container and execute Bitmessage
    ssh -oStrictHostKeyChecking=no -oUserKnownHostsFile=/dev/null -oIdentityFile=~/.config/PyBitmessage/keys/docker-bitmessage-keys -X $DIP ./PyBitmessage/src/bitmessagemain.py

    # close container if Bitmessage is closed
    docker kill $DID

    Okay, let’s make it executable: chmod +x bitmessage

    Put a link to it where it can be picked up system-wide: ln -fs ~/docker-bitmessage/bitmessage /usr/local/bin/bitmessage

    There we have it! We now have a functional Bitmessage inside a Docker container. \o/

    In a future post we’ll look at using eCryptfs to further protect our Bitmessage data stores.

      Project files: Github and Docker


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    Permalink: 20170217.making.a.docker.bitmessage

    Tue, 10 Jan 2017

    [-] Auxiliary failed: Msf::OptionValidateError The following options failed to validate: RHOSTS.

    Mucking about with a fresh copy of Kali brings to attention that it’s packaged with an Armitage that doesn’t correctly work.

    I know what you’re thinking… Good. Type the commands into Msfconsole like a real man, y’uh lazy good-fer-naught! And, in practice, that was my immediate solution. But I can’t resist a good tinker when things are misbehaving.

    I was anticipating that the problem would be thoroughly solved when I ixquicked it. That was partially correct. Surprised, however, when apt-get update && apt-get upgrade didn’t fix the issue. More surprised at the age of the issue. Most surprised that I could see lots of evidence that users have been plagued by this issue — but no clear work arounds were quickly found.

    Guess what we’re doing today?

    Okay. The issue is quite minor but just enough to be heartbreaking to the fledgling pentester trying to get a VM off the ground.

    In brief, the owner of Armitage’s Github explains:

    The MSF Scans feature in Armitage parses output from Metasploit’s portscan/tcp module and uses these results to build a list of targets it should run various Metasploit auxiliary modules against. A recent-ish update to the Metasploit Framework changed the format of the portscan/tcp module output. A patch to fix this issue just needs to account for the new format of the portscan/tcp module.

    That is, a colon makes it into the input for the Msfconsole command to define RHOSTS. I.e.: set RHOSTS 172.16.223.150: - 172.16.223.150

    An other kind coder tweaked the regex and submitted the patch and pull request, which was successfully incorporated into the project.

    Sadly, things have stalled out there. So if this problem is crippling your rig, let’s fix it!

    We just want a fresh copy of the project.
    root@kali:~/armitage# git clone https://github.com/rsmudge/armitage

    Cloning into ‘armitage’…
    remote: Counting objects: 7564, done.
    remote: Total 7564 (delta 0), reused 0 (delta 0), pack-reused 7564
    Receiving objects: 100% (7564/7564), 47.12 MiB | 2.91 MiB/s, done.
    Resolving deltas: 100% (5608/5608), done.

    Kali is Debian-based and we’re going to need Apache Ant:
    root@kali:~/armitage# apt-get install ant

    Then, we’ll build our new fella:
    root@kali:~/armitage# cd armitage
    root@kali:~/armitage# ./package.sh

    Buildfile: /root/test/armitage/build.xml

    clean:

    BUILD SUCCESSFUL
    Total time: 0 seconds
    Buildfile: /root/test/armitage/build.xml

    init:
    [mkdir] Created dir: /root/test/armitage/bin

    compile:
    [javac] Compiling 111 source files to /root/test/armitage/bin
    [javac] depend attribute is not supported by the modern compiler
    [javac] Note: /root/test/armitage/src/ui/MultiFrame.java uses or overrides a deprecated API.
    [javac] Note: Recompile with -Xlint:deprecation for details.
    [javac] Note: Some input files use unchecked or unsafe operations.
    [javac] Note: Recompile with -Xlint:unchecked for details.

    BUILD SUCCESSFUL
    Total time: 2 seconds
    Buildfile: /root/test/armitage/build.xml

    init:

    compile:

    jar:
    [unzip] Expanding: /root/test/armitage/lib/sleep.jar into /root/test/armitage/bin
    [unzip] Expanding: /root/test/armitage/lib/jgraphx.jar into /root/test/armitage/bin
    [unzip] Expanding: /root/test/armitage/lib/msgpack-0.6.12-devel.jar into /root/test/armitage/bin
    [unzip] Expanding: /root/test/armitage/lib/postgresql-9.1-901.jdbc4.jar into /root/test/armitage/bin
    [unzip] Expanding: /root/test/armitage/lib/javassist-3.15.0-GA.jar into /root/test/armitage/bin
    [copy] Copying 4 files to /root/test/armitage/bin/scripts-cortana
    [jar] Building jar: /root/test/armitage/armitage.jar
    [jar] Building jar: /root/test/armitage/cortana.jar

    BUILD SUCCESSFUL
    Total time: 1 second
    armitage/
    armitage/readme.txt
    armitage/teamserver
    armitage/cortana.jar
    armitage/armitage.jar
    armitage/armitage-logo.png
    armitage/armitage
    armitage/whatsnew.txt
    adding: readme.txt (deflated 55%)
    adding: armitage.exe (deflated 49%)
    adding: cortana.jar (deflated 5%)
    adding: armitage.jar (deflated 5%)
    adding: whatsnew.txt (deflated 65%)
    armitage/
    armitage/readme.txt
    armitage/teamserver
    armitage/cortana.jar
    armitage/armitage.jar
    armitage/armitage-logo.png
    armitage/armitage
    armitage/whatsnew.txt
    Archive: ../../armitage.zip
    inflating: readme.txt
    inflating: armitage.exe
    inflating: cortana.jar
    inflating: armitage.jar
    inflating: whatsnew.txt

    And here, best I can guess from messages read, is where a lot of people are running into trouble. We have successfully produced our new working copy of armitage. However, it is in our own local directory and will not be run if we just enter the command: armitage

    Let’s review how to figure out what we want to do about that.

    First, we want to verify what happens when we run the command armitage.
    root@kali:~/armitage# which armitage

    /usr/bin/armitage

    Good! Let’s check and see what that does!
    root@kali:~/armitage# head /usr/bin/armitage

    #!/bin/sh

    cd /usr/share/armitage/
    exec ./armitage “$@”

    Almost there! It’s running /usr/share/armitage/armitage with whatever variables we’ve passed in. We’ll check that out.
    root@kali:~/armitage# head /usr/share/armitage/armitage

    #!/bin/sh
    java -XX:+AggressiveHeap -XX:+UseParallelGC -jar armitage.jar $@

    We have enough information to assemble a solution.

    I trust that the people behind Kali and Armitage will get this corrected so I don’t want to suggest a solution that would replace the armitage command and prevent an updated version from running later. So, let’s just make a temporary replacement?

    root@kali:~/armitage# echo -e '#!/bin/sh\njava -XX:+AggressiveHeap -XX:+UseParallelGC -jar ~/armitage/armitage.jar $@' > /usr/bin/tmparmitage

    Hereafter, we can use the command ‘tmparmitage’ (either CLI or ALT-F2) to run our fresh version until things catch up.

    And, of course, to save you the time, weary hacker:

    Download here:
        armitage_quick_fix.sh


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    Permalink: 20170110.armitage.not.working.in.kali

    Sun, 13 Jul 2014

    Simple Protection with iptables, ipset and Blacklists

    Seems I’ve always just a few more things going on than I can comfortably handle. One of those is an innocent little server holding the beginnings of a new project.

    If you expose a server to the Internet, very quickly your ports are getting scanned and tested. If you’ve an SSH server, there are going to be attempts to login as ‘root’ which is why it is ubiquitously advised that you disable root login. Also why many advise against allowing passwords at all.

    We could talk for days about improvements; it’s usually not difficult to introduce some form of two-factor authentication (2FA) for sensitive points of entry such as SSH. You can install monitoring software like Logwatch which can summarize important points from your logs, such as: who has logged via SSH, how many times root was used, etc.

    DenyHosts and Fail2ban are very great ways to secure things, according to your needs.

    DenyHosts works primarily with SSH and asks very little from you in way of configuration, especially if you’re using a package manager to install a version that is configured for the distribution on which you’re working. If you’re installing from source you may need to find where are your SSH logs (e.g., /var/log/secure, /var/log/auth.log). It’s extremely easy to set up DenyHosts to synchronize so that you’re automatically blocking widely-known offenders whether or not they’re after your server.

    In contrast, Fail2ban is going to take more work to get set up. However, it is extremely configurable and works with any log file you point it toward which means that it can watch anything (e.g., FTP, web traffic, mail traffic). You define your own jails which means you can ban problematic IP addresses according to preference. Ban bad HTTP attempts from HTTP only or stick their noses in the virtual corner and don’t accept any traffic from them until they’ve served their time-out by completely disallowing their traffic. You can even use Fail2ban to scan its own logs, so repeating offenders can be locked out for longer.

    Today we’re going to assume that you’ve a new server that shouldn’t be seeing any traffic except from you and any others involved in the project. In that case, you probably want to block traffic pretty aggressively. If you’ve physical access to the server (or the ability to work with staff at the datacenter) then it’s better to err in the direction of accidentally blocking good guys than trying to be overly fault-tolerant.

    The server we’re working on today is a Debian Wheezy system. It has become a common misconception that Ubuntu and Debian are, intents and purposes, interchangeable. They’re similar in many respects and Ubuntu is great preparation for using Debian but they are not the same. The differences, I think, won’t matter for this exercise but I am unsure because this was written using Wheezy.

    Several minutes after bringing my new server online, I started seeing noise in the logs. I was still getting set up and really didn’t want to stop and take protective measures but there’s no point in securing a server after its been compromised. The default Fail2ban configuration was too forgiving for my use. It was scanning for 10 minutes and banning for 10 minutes. Since only a few people should be accessing this server, there’s no reason for anyone to be trying a different password every 15 minutes (for hours).

    I found a ‘close-enough’ script and modified it. Here, we’ll deal with a simplified version.

    First, lets create a name for these ne’er-do-wells in iptables:
    iptables -N bad_traffic

    For this one, we’ll use Perl. We’ll look at our Apache log files to find people sniffing ‘round and we’ll block their traffic. Specifically, we’re going to check Apache’s ‘error.log’ for the phrases ‘File does not exist’ and ‘client denied by server configuration’ and block people causing those errors. This would be excessive for servers intended to serve the general populace. For a personal project, it works just fine as a ‘DO NOT DISTURB’ sign.


    #!/usr/bin/env perl
    use strict;
    use POSIX qw(strftime);

    my $log = ($ARGV[0] ? $ARGV[0] : "/var/log/apache2/error.log");
    my $chain = ($ARGV[1] ? $ARGV[1] : "bad_traffic");

    my @bad = `grep -iE 'File does not exist|client denied by server configuration' $log |cut -f8 -d" " | sed 's/]//' | sort -u`;
    my @ablk = `/sbin/iptables -S $chain|grep DROP|awk '{print $4}'|cut -d"/" -f1`;

    foreach my $ip (@bad) {
    if (!grep $_ eq $ip, @ablk) {
    chomp $ip;
    `/sbin/iptables -A $chain -s $ip -j DROP`;
    print strftime("%b %d %T",localtime(time))." badht: blocked bad HTTP traffic from: $ip\n";
    }
    }

    That gives us some great, utterly unforgiving, blockage. Looking at the IP addresses attempting to pry, I noticed that most of them were on at least one of the popular block-lists.

    So let’s make use of some of those block-lists! I found a program intended to apply those lists locally but, of course, it didn’t work for me. Here’s a similar program; this one will use ipset for managing the block-list though only minor changes would be needed to use iptables as above:

    #!/bin/bash
    IP_TMP=ip.tmp
    IP_BLACKLIST_TMP=ip-blacklist.tmp

    IP_BLACKLIST=ip-blacklist.conf

    WIZ_LISTS="chinese nigerian russian lacnic exploited-servers"

    BLACKLISTS=(
    "http://danger.rulez.sk/projects/bruteforceblocker/blist.php" # BruteForceBlocker IP List
    "http://rules.emergingthreats.net/blockrules/compromised-ips.txt" # Emerging Threats - Compromised IPs
    "http://www.spamhaus.org/drop/drop.txt" # Spamhaus Don't Route Or Peer List (DROP)
    "http://www.spamhaus.org/drop/edrop.txt" # Spamhaus Don't Route Or Peer List (DROP) Extended
    "http://cinsscore.com/list/ci-badguys.txt" # C.I. Army Malicious IP List
    "http://www.openbl.org/lists/base.txt" # OpenBL.org 90 day List
    "http://www.autoshun.org/files/shunlist.csv" # Autoshun Shun List
    "http://lists.blocklist.de/lists/all.txt" # blocklist.de attackers
    )

    for address in "${BLACKLISTS[@]}"
    do
    echo -e "\nFetching $address\n"
    curl "$address" >> $IP_TMP
    done

    for list in $WIZ_LISTS
    do
    wget "http://www.wizcrafts.net/$list-iptables-blocklist.html" -O - >> $IP_TMP
    done

    wget 'http://wget-mirrors.uceprotect.net/rbldnsd-all/dnsbl-3.uceprotect.net.gz' -O - | gunzip | tee -a $IP_TMP

    grep -o '^[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}[/][0-9]\{1,3\}' $IP_TMP | tee -a $IP_BLACKLIST_TMP
    grep -o '^[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}[^/]' $IP_TMP | tee -a $IP_BLACKLIST_TMP

    sed -i 's/\t//g' $IP_BLACKLIST_TMP
    sort -u $IP_BLACKLIST_TMP | tee $IP_BLACKLIST

    rm $IP_TMP
    rm $IP_BLACKLIST_TMP

    wc -l $IP_BLACKLIST

    if hash ipset 2>/dev/null
    then
    ipset flush bloxlist
    while IFS= read -r ip
    do
    ipset add bloxlist $ip
    done < $IP_BLACKLIST
    else
    echo -e '\nipset not found\n'
    echo -e "\nYour bloxlist file is: $IP_BLACKLIST\n"
    fi


    Download here:
        bad_traffic.pl
        bloxlist.sh


    Tags: , , , , , , , , , ,
    Permalink: 20140713.simple.protection.with.iptables.ipset.and.blacklilsts

    Sat, 25 Jan 2014

    Network-aware Synergy client

    My primary machines are *nix or BSD variants, though I certainly have some Windows-based rigs also. Today we’re going to share some love with Windows 7 and PowerShell.

    One of my favorite utilities is Synergy. If you’re not already familiar it allows to you seamlessly move from the desktop of one computer to another with the same keyboard and mouse. It even supports the clipboard so you might copy text from a GNU/Linux box and paste it in a Windows’ window. Possibly, they have finished adding drag and drop to the newer versions. I am not sure because I run a relatively old version that is supported by all of the machines that I use regularly.

    What’s the problem, then? The problem was that I was starting my Synergy client by hand. Even more disturbing, I was manually typing the IP address at work and at home, twice or more per weekday. This behavior became automated by my brain and continued for months unnoticed. But this is no kind of life for a geek such as myself, what with all this superfluous clicking and tapping!

    Today, we set things right!

    In my situation, the networks that I use happen to assign IP addresses from different subnets. If you’ve not the convenience of that situation then you might need to add something to the script. Parsing an ipconfig/ifconfig command, you could possibly use something like the Default Gateway or the Connection-specific DNS Suffix. Alternatively, you could check for the presence of some network share, a file on server or anything that would allow you to uniquely identify the surroundings.

    As I imagined it, I wanted the script to accomplish the following things

    • see if Synergy is running (possibly from the last location), if so ask if we need to kill it and restart so we can identify a new server
    • attempt to locate where we are and connect to the correct Synergy server
    • if the location is not identified, ask whether to start the Synergy client

    This is how I accomplished that task:

    # [void] simply supresses the noise made loading 'System.Reflection.Assembly'
    [void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")

    # Define Synergy server IP addresses
    $synergyServerWork = "192.168.111.11"
    $synergyServerHome = "192.168.222.22"

    # Define partial IP addresses that will indicate which server to use
    $synergyWorkSubnets = "192.168.111", "192.168.115"
    $synergyHomeSubnets = "192.168.222", "192.168.225"

    # Path to Synergy Client (synergyc)
    $synergyClientProgram = "C:\Program Files\Synergy\synergyc.exe"

    # Path to Syngery launcher, for when we cannot identify the network
    $synergyLauncherProgram = "C:\Program Files\Synergy\launcher.exe"

    # Remove path and file extension to give us the process name
    $processName = $synergyClientProgram.Substring( ($synergyClientProgram.lastindexof("\") + 1), ($synergyClientProgram.length - ($synergyClientProgram.lastindexof("\") + 5) ))

    # Grab current IP address
    $currentIPaddress = ((ipconfig | findstr [0-9].\.)[0]).Split()[-1]

    # Find the subnet of current IP address
    $location = $currentIPaddress.Substring(0,$currentIPaddress.lastindexof("."))


    function BalloonTip ($message)
    {
    # Pop-up message from System Tray
    $objNotifyIcon = New-Object System.Windows.Forms.NotifyIcon
    $objNotifyIcon.Icon = [System.Drawing.Icon]::ExtractAssociatedIcon($synergyClientProgram)
    $objNotifyIcon.BalloonTipText = $message
    $objNotifyIcon.Visible = $True
    $objNotifyIcon.ShowBalloonTip(15000)
    }


    #main

    # If Synergy client is already running, do we need to restart it?
    $running = Get-Process $processName -ErrorAction SilentlyContinue
    if ($running) {
    $answer = [System.Windows.Forms.MessageBox]::Show("Synergy is running.`nClose and start again?", "OHNOES", 4)
    if ($answer -eq "YES") {
    Stop-Process -name $processName
    }
    Else {
    exit
    }
    }

    # Do we recognize the current network?
    if ($synergyWorkSubnets -contains $location) {
    BalloonTip "IP: $($currentIPaddress)`nServer: $($synergyServerWork)`nConnecting to Synergy server at work."
    & $synergyClientProgram $synergyServerWork
    exit
    }
    ElseIf ($synergyHomeSubnets -contains $location) {
    BalloonTip "IP: $($currentIPaddress)`nServer: $($synergyServerHome)`nConnecting to Synergy server at home."
    & $synergyClientProgram $synergyServerHome
    exit
    }
    Else {
    $answer = [System.Windows.Forms.MessageBox]::Show("Network not recognized by IP address: {0}`n`nLaunch Synergy?" -f $unrecognized, "OHNOES", 4)
    if ($answer -eq "YES") {
    & $synergyLauncherProgram
    }
    }

    Then I saved the script in "C:\Program Files\SynergyStart\", created a shortcut and used the Change Icon button to make the same as Synergy’s and made the Target:
    C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -WindowStyle Hidden & 'C:\Program Files\SynergyStart\synergy.ps1'

    Lastly, I copied the shortcut into the directory of things that run when the system starts up:
    %APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup

    Now, Synergy connects to the needed server at home and work. If it can’t figure out where it is, it asks if it should run it at all.

    As they say, a millisecond saved is a millisecond earned.

    This post was very nearly published without a Linux equivalent. Nearly.

    Same trick for bash/zsh: #!/bin/zsh

    # Define Synergy server IP addresses
    synergyServerWork="192.168.111.11"
    synergyServerHome="192.168.222.22"

    # Define partial IP addresses that will indicate which server to use
    synergyWorkSubnets=("192.168.111" "192.168.115")
    synergyHomeSubnets=("192.168.222" "192.168.225")

    # Path to Synergy Client (synergyc)
    synergyClientProgram="/usr/bin/synergyc"

    # Path to QuickSyngery, for when we cannot identify the network
    synergyLauncherProgram="/usr/bin/quicksynergy"

    # Remove path and file extension to give us the process name
    processName=`basename $synergyClientProgram`

    # Grab current IP address, assumes '192' is in use. (e.g., 192.168.1.1)
    currentIPaddress=`ip addr show | grep 192 | awk "{print $2}" | sed 's/inet //;s/\/.*//;s/ //g'`

    # Find the subnet of current IP address
    location=`echo $currentIPaddress | cut -d '.' -f 1,2,3`

    for i in "${synergyWorkSubnets[@]}"
    do
    if [ "${i}" = "${location}" ]
    then
    break
    fi
    done

    #main

    # If Synergy client is already running, do we need to restart it?
    running=`ps ax | grep -v grep | grep $processName`
    if [ $running ]
    then
    if `zenity --question --ok-label="Yes" --cancel-label="No" --text="Synergy is running.\nClose and start again?"`
    then
    pkill $processName
    else
    exit
    fi
    fi

    # Do we recognize the current network?
    for i in "${synergyWorkSubnets[@]}"
    do
    if [ "${i}" = "${location}" ]
    then
    notify-send "IP:$currentIPaddress Server:$synergyServerWork [WORK]"
    $synergyClientProgram $synergyServerWork
    exit
    fi
    done

    for i in "${synergyHomeSubnets[@]}"
    do
    if [ "${i}" = "${location}" ]
    then
    notify-send "IP:$currentIPaddress Server:$synergyServerWork [HOME]"
    $synergyClientProgram $synergyServerHome
    exit
    fi
    done

    if `zenity --question --ok-label="Yes" --cancel-label="No" --text="Network not recognized by IP address: $currentIPaddress\nLaunch Synergy?"`
    then
    $synergyLauncherProgram
    fi

    To get it to run automatically, you might choose to call the script from /etc/init.d/rc.local.

    Download here:
      PowerShell:
        synergy.ps1
      GNU/Linux:
        synergy.sh


    Tags: , ,
    Permalink: 20140125.network_aware_synergy_client

    Thu, 30 May 2013

    Making ixquick your default search engine

    In this writer’s opinion, it is vitally important that we take reasonable measures now to help insure anonymity, lest we create a situation where privacy no longer exists, and the simple want of, becomes suspicious.

    Here’s how to configure your browser to automatically use a search engine that respects your privacy.

    Chrome:

    1. Click Settings.
    2. Click “Set pages” in the “On startup” section.
    3. Enter https://ixquick.com/eng/ in the “Add a new page” text field.
    4. Click OK.
    5. Click “Manage search engines…”
    6. At the bottom of the “Search Engines” dialog, click in the “Add a new search engine” field.
    7. Enter
      ixquick
      ixquick.com
      https://ixquick.com/do/search?lui=english&language=english&cat=web&query=%s
    8. Click “Make Default”.
    9. Click “Done”.

    Firefox:

    1. Click the Tools Menu.
    2. Click Options.
    3. Click the General tab.
    4. In “When Firefox Starts” dropdown, select “Show my home page”.
    5. Enter https://ixquick.com/eng/ in the “Home Page” text field.
    6. Click one of the English options here.
    7. Check box for “Start using it right away.”
    8. Click “Add”.

    Opera:

    1. Click “Manage Search Engines
    2. Click “Add”
    3. Enter
      Name: ixquick
      Keyword: x
      Address: https://ixquick.com/do/search?lui=english&language=english&cat=web&query=%s
    4. Check “Use as default search engine”
    5. Click “OK”

    Internet Explorer:

        _     ___  _ __        ___   _ _____ ___ 
       | |   / _ \| |\ \      / / | | |_   _|__ \
       | |  | | | | | \ \ /\ / /| | | | | |   / /
       | |__| |_| | |__\ V  V / | |_| | | |  |_| 
       |_____\___/|_____\_/\_/   \___/  |_|  (_) 
      
      
      (This is not a good strategy for privacy.)

    Congratulations!

    \o/

    You are now one step closer to not having every motion on the Internet recorded.

    This is a relatively small measure, though. You can improve your resistance to prying eyes (e.g., browser fingerprinting) by using the Torbrowser Bundle, or even better, Tails, and routing your web usage through Tor, i2p, or FreeNet.

    If you would like more on subjects like anonymyzing, privacy and security then drop me a line via email or Bitmessage me: BM-2D9tDkYEJSTnEkGDKf7xYA5rUj2ihETxVR


    Tags: , , , , , , , , , , , , , ,
    Permalink: 20130530.hey.you.get.offa.my.data

    Mon, 20 May 2013

    Debugging PHP with Xdebug

    I have finished (more-or-less) making a demo for the Xdebug togglin’ add-on/extension that I’ve developed.

    One hundred percent of the feedback about this project has been from Chrome users. Therefore, the Chrome extension has advanced with the new features (v2.0), allowing selective en/dis-ableing portions of Xdebug’s output. That is you can set Xdebug to firehose mode (spitting out everything) and then squelch anything not immediately needed at the browser layer. The other information remains present, hidden in the background, available if you decide that you need to have a look.

    The Firefox version is still at v1.2 but will be brought up to speed as time permits.

    If you want that firehose mode for Xdebug, here’s a sample of some settings for your configuration ‘.ini’ file.

    The demo is here.


    Tags: , , , , , , ,
    Permalink: 20130520.debugging.php.with.xdebug

    Tue, 07 May 2013

    Welcome, traveler.

    Thanks for visiting my little spot on the web. This is a Blosxom ‘blog which, for those who don’t know, is a CGI written in Perl using the file-system (rather than a database).

    To the CLI-addicted, this is an awesome little product. Accepting, of course, that you’re going to get under the hood if you’re going to make it the product you want. After some modules and hacking, I’m pleased with the result.

    My posts are just text files, meaning I start a new one like: vim ~posts/`date +%Y%m%d`.brief.subject.txt

    Note: the back-ticks (`) tell the system that you want to execute the command between ticks, and dynamically insert its output into the command. In this case, the command date with these parameters:
    1. (+) we’re going to specify a format
    2. (%Y) four-digit year
    3. (%m) two-digit month
    4. (%d) two-digit day
    That means the command above will use Vim to edit a text file named ‘20130507.brief.subject.txt’ in the directory I have assigned to the hash of ‘posts’. (using hash this way is a function of Zsh that I’ll cover in another post)

    In my CLI-oriented ‘blog, I can sprinkle in my own HTML or use common notation like wrapping a word in underscores to have it underlined, forward-slashes for italics and asterisks for bold.

    Toss in a line that identifies tags and, since Perl is the beast of Regex, we pick up the tags and make them links, meta-tags, etc.

    Things here are likely to change a lot at first, while I twiddle with CSS and hack away at making a Blosxom that perfectly fits my tastes — so don’t be too alarmed if you visit and things look a tad wonky. It just means that I’m tinkering.

    Once the saw-horses have been tucked away, I’m going to take the various notes I’ve made during my years in IT and write them out, in a very simple breakdown, aimed at sharing these with people who know little about how to negotiate the command line. The assumption here is that you have an interest in *nix/BSD. If you’ve that and the CLI is not a major part of your computing experience, it probably will be at some point. If you’re working on systems remotely, graphical interfaces often just impede you.

    Once you’ve started working on remote machines, the rest is inevitable. You can either remember how to do everything two ways, through a graphical interface and CLI — or just start using the CLI for everything.

    So let’s take a little journey through the kinds of things that make me love the CLI.


    Tags: , , , , , , , , ,
    Permalink: 20130507.greetings