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

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, 20 Dec 2016

Kicking the Crypto-tires

Some time ago I had begun work on my own Pastebin-type project with a few goals. Basically, I wanted to eat all the cakes — and have them too.

  • Both an online user interface and efficient CLI usage
  • Messages encrypted immediately such that database access does not provide one with the contents of the messages
  • Messages capable of self-destructing
  • Database schema that would allow rebuilding the user/message relationship, provided the same password but would not store those relationships
  • Also, JavaScript encryption to appeal to users who don’t know much about cryptography but would like to try
  • The project, honestly, was going swimmingly when derailed by the goings-on of life.

    One of the interesting components of the project was, of course, choosing crypto implementations. There are know shortcomings to handling it in JS but that’s still the most convenient for some users. Outside of the browser, server-side, you had all the same questions about which solution was best. Which protocol(s) should be available?

    Well, I’ve just learned about a project which I would have loved to have available back then. Project Wycheproof can help you test your crypto solutions against known problems and attacks. Featuring 80 tests probing at 40 known bugs, here’s a snip from the introduction:

    Project Wycheproof has tests for the most popular crypto algorithms, including

  • AES-EAXAES-GCM
  • AES-GCM
  • DH
  • DHIES
  • DSA
  • ECDH
  • ECDSA
  • ECIES
  • RSA
  • The tests detect whether a library is vulnerable to many attacks, including

  • Invalid curve attacks
  • Biased nonces in digital signature schemes
  • Of course, all Bleichenbacher’s attacks
  • And many more — we have over 80 test cases
  • Interesting stuff with exciting potential!


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    Permalink: 20161220.kicking.the.crypto.tires

    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


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

    Thu, 06 Jun 2013

    Managing to use man pages through simple CLI tips

    Recently, an author I admire and time-honored spinner of the Interwebs, Tony Lawrence emphasized the value of using man pagesmanual pagesDocumentation available from the command line.
    > man ls
    as a sanity check before getting carried away with powerful commands. I didn’t know about this one but he has written about a situation in which killall could produce some shocking, and potentially quite unpleasant, results.

    Personally, I often quickly check man pages to be certain that I am using the correct flags or, as in the above case, anticipating results that bear some resemblance to what is actually likely to happen. Yet, it seems many people flock toward SERPSearch Engine Results Page A tasteful replacement for mentioning any particular search-engine by name.
    Also useful as a verb:
    I dunno. You’ll have to SERP it.
    s for this information.

    Perhaps the most compelling reason to head for the web is leaving the cursor amid the line you’re working on, without disturbing the command. SERPing the command however, could easily lead you to information about a variant that is more common than the one available to you. More importantly, the information retrieved from the search engine is almost certainly written by someone who did read the man page — and may even come with the admonishment that you RTFMRead The F#!$!*#’n Manual as a testament to the importance of developing this habit.

    This can be made easier with just a few CLI shortcuts.

    <CTRL+u> to cut what you have typed so far and <CTRL+y> to paste it back.

    That is, you press <CTRL+u> and the line will be cleared, so you can then type man {command} and read the documentation. Don’t hesitate to jot quick notes of which flags you intend to use, if needed. Then exit the man page, press <CTRL+y> and finish typing right where you left off.

    This is another good use for screen or tmux but let’s face it. There are times when you don’t want the overhead of opening another window for a quick look-up and even instances when these tools aren’t available.

    A few other tips to make life easier when building complex commands:

    Use the command fc to open up an editor in which you can build your complex command and, optionally, even save it as a shell script for future reuse.

    Repeat the last word from the previous command (often a filename) with <ALT+.> or use an item from the last command by position, in reverse order:
    > ls -lahtr *archive*
    <ALT+1+.> : *archive*
    <ALT+2+.> : -lahtr
    <ALT+3+.> : ls

    You can also use Word Designators to use items from history, such as adding sudo to the last command typed by:
    sudo !!

    This allows for tricks like replacing bits of a previous command:
    !:s/misspelled/corrected/

    Lastly, if you need a command that was typed earlier, you can search history by pressing <CTRL+r> and start typing an identifying portion of the command.

    (Note: I have used these in Zsh and Bash, specifically. They can, however, be missing or overwritten — if a feature you want isn’t working, you can bind keys in a configuration file. Don’t just write it off, once you’ve solved the problem it will never again be an intimidating one.)

    Happy hacking!


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    Permalink: 20130606.managing.to.use.man.pages

    Tue, 04 Jun 2013

    Painless protection with Yubico’s Yubikey

    Recently, I ordered a Yubikey and, in the comments section of the order, I promised to write about the product. At the time, I assumed that there was going to be something about which to write: (at least a few) steps of setting up and configuration or a registration process. They’ve made the task of writing about it difficult, by making the process of using it so easy.

    Plug it in. The light turns solid green and you push the button when you need to enter the key. That’s the whole thing!

    Physically, the device has a hole for a keychain or it can slip easily into your wallet. It draws power from the USB port on the computer, so there’s none stored in the device, meaning it should be completely unfazed if you accidentally get it wet.

    Let’s take a look at the device.

    > lsusb | grep Yubico

    Bus 005 Device 004: ID 1050:0010 Yubico.com Yubikey

    We see that it is on Bus 5, Device 4. How about a closer look?

    > lsusb -v -s5:4

    Bus 005 Device 004: ID 1050:0010 Yubico.com Yubikey
    Couldn't open device, some information will be missing
    Device Descriptor:
      bLength                18
      bDescriptorType         1
      bcdUSB               2.00
      bDeviceClass            0 (Defined at Interface level)
      bDeviceSubClass         0 
      bDeviceProtocol         0 
      bMaxPacketSize0         8
      idVendor           0x1050 Yubico.com
      idProduct          0x0010 Yubikey
      bcdDevice            2.41
      iManufacturer           1 
      iProduct                2 
      iSerial                 0 
      bNumConfigurations      1
      Configuration Descriptor:
        bLength                 9
        bDescriptorType         2
        wTotalLength           34
        bNumInterfaces          1
        bConfigurationValue     1
        iConfiguration          0 
        bmAttributes         0x80
          (Bus Powered)
        MaxPower               30mA
        Interface Descriptor:
          bLength                 9
          bDescriptorType         4
          bInterfaceNumber        0
          bAlternateSetting       0
          bNumEndpoints           1
          bInterfaceClass         3 Human Interface Device
          bInterfaceSubClass      1 Boot Interface Subclass
          bInterfaceProtocol      1 Keyboard
          iInterface              0 
            HID Device Descriptor:
              bLength                 9
              bDescriptorType        33
              bcdHID               1.11
              bCountryCode            0 Not supported
              bNumDescriptors         1
              bDescriptorType        34 Report
              wDescriptorLength      71
             Report Descriptors: 
               ** UNAVAILABLE **
          Endpoint Descriptor:
            bLength                 7
            bDescriptorType         5
            bEndpointAddress     0x81  EP 1 IN
            bmAttributes            3
              Transfer Type            Interrupt
              Synch Type               None
              Usage Type               Data
            wMaxPacketSize     0x0008  1x 8 bytes
            bInterval              10
    

    There’s not a great deal to be seen here. As it tells you right on Yubico’s site, the device presents as a keyboard and it “types” out its key when you press the button, adding another long and complex password to combine with the long and complex password that you’re already using.

    Keep in mind that this device is unable to protect you from keyloggers, some of which are hardware-based. It’s critically important that you are very, very careful about where you’re sticking your Yubikey. Even Yubico cannot protect us from ourselves.


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    Permalink: 20130604.yay.yubico.yubikey

    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


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

    Thu, 23 May 2013

    GNU Screen: Roll your own system monitor

    Working on remote servers, some tools are practically ubiquitous — while others are harder to come by. Even if you’ve the authority to install your preferred tools on every server you visit, it’s not always something you want to do. If you’ve hopped on to a friend’s server just to troubleshoot a problem, there is little reason to install tools that your friend is not in the habit of using. Some servers, for security reasons, are very tightly locked down to include only a core set of tools, to complicate the job of any prying intruders. Or perhaps it is a machine that you normally use through a graphical interface but on this occasion you need to work from the CLI.

    These are very compelling reasons to get comfortable, at the very least, with tools like Vim, mail, grep and sed. Eventually, you’re likely to encounter a situation where only the classic tools are available. If you aren’t competent with those tools, you’ll end up facing the obstacle of how to get files from the server to your local environment where you can work and, subsequently, how to get the files back when you’re done. In a secured environment, this may not be possible without violating protocols.

    Let’s take a look at how we can build a makeshift system monitor using some common tools. This particular configuration is for a server running PHP, MySQL and has the tools Htop and mytop installed. These can easily be replaced with top and a small script to SHOW FULL PROCESSLIST, if needed. The point here is illustrative, to provide a template to be modified according to each specific environment.

    (Note: I generally prefer tmux to Gnu Screen but screen is the tool more likely to be already installed, so we’ll use it for this example.)

    We’re going to make a set of windows, by a configuration file, to help us keep tabs on what is happening in this system. In so doing, we’ll be using the well-known tools less and watch. More specifically, less +F which tells less to “scroll forward”. Other words, less will continue to read the file making sure any new lines are added to the display. You can exit this mode with CTRL+c, search the file (/), quit(q) or get back into scroll-forward mode with another uppercase F.

    Using watch, we’ll include the “-d” flag which tells watch we want to highlight any changes (differences).

    We will create a configuration file for screen by typing:

    > vim monitor.screenrc

    In the file, paste the following:

    # Screen setup for system monitoring
    # screen -c monitor.screenrc
    hardstatus alwayslastline
    hardstatus string '%{= kG}[ %{G}%H %{g}][%= %{=kw}%?%-Lw%?%{r}(%{W}%n*%f%t%?(%u)%?%{r})%{w}%?%+Lw%?%?%= %{g}][%{B}%Y-%m-%d %{W}%c %{g}]'

    screen -t htop 0 htop
    screen -t mem 1 watch -d "free -t -m"
    screen -t mpstat 2 watch -d "mpstat -A"
    screen -t iostat 3 watch -d "iostat"
    screen -t w 4 watch -d "w"
    screen -t messages 5 less +F /var/log/messages
    screen -t warn 6 less +F /var/log/warn
    screen -t database 7 less +F /srv/www/log/db_error
    screen -t mytop 8 mytop
    screen -t php 9 less +F /srv/www/log/php_error

    (Note: -t sets the title, then the window number, followed by the command running in that window)

    Save the file (:wq) or, if you’d prefer, you can grab a copy by right-clicking and saving this file.

    Then we will execute screen using this configuration, as noted in the comment:

    > screen -c monitor.screenrc

    Then you can switch between windows using CTRL+a, n (next) or CTRL+a, p (previous).

    I use this technique on my own computers, running in a TTY different from the one used by X. If the graphical interface should get flaky, I can simply switch to that TTY (e.g., CTRL+ALT+F5) to see what things are going on — and take corrective actions, if needed.


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    Permalink: 20130523.gnu.screen.system.monitor

    Wed, 15 May 2013

    Git: an untracked mess?

    There may be times when you find your Git repository burdened with scads of untracked files left aside while twiddling, testing bug patches, or what-have-youse.

    For the especially scatter-brained among us, these things can go unchecked until a day when the useful bits of a git status scroll off the screen due to utterly unimportant stuff. Well, hopefully unimportant.

    But we’d better not just cleave away everything that we haven’t checked in. You wonder:
    What if there’s something important in one of those files?

    You are so right!

    Let’s fix this!

    Firstly, we want a solution that’s reproducible. Only want to invent this wheel once, right?

    Let’s begin with the play-by-play:

    Git, we want a list of what isn’t tracked: git ls-files -o --exclude-standard -z

    We’ll back these files up in our home directory (~), using CPIO but we don’t want a poorly-named directory or finding anything will become its own obstacle. So we’ll take use the current date (date +%Y-%m-%d), directory (pwd) and branch we’re using (git branch) and we’ll twist all of it into a meaningful, but appropriate, directory name using sed. git ls-files -o --exclude-standard -z | cpio -pmdu ~/untracked-git-backup-`date +%Y-%m-%d`.`pwd | sed 's,^\(.*/\)\?\([^/]*\),\2,'`.`git branch | grep "*" | sed "s/* //"`/

    Then Tell Git to remove the untracked files and directories: git clean -d -f

    Ahhhh… Much better. Is there anything left out? Perhaps. What if we decide that moving these files away was a mistake? The kind of mistake that breaks something. If we realize right away, it’s easily-enough undone. But what if we break something and don’t notice for a week or two? It’d probably be best if we had an automated script to put things back the way they were. Let’s do that.

    Simple enough. We’ll just take the opposite commands and echo them into a script to be used in case of emergency.

    Create the restore script (restore.sh), to excuse faulty memory: echo "(cd ~/untracked-git-backup-`date +%Y-%m-%d`.`pwd | sed 's,^\(.*/\)\?\([^/]*\),\2,'`.`git branch | grep "*" | sed "s/* //"`/; find . -type f \( ! -iname 'restore.sh' \) | cpio -pdm `pwd`)" > ~/untracked-git-backup-`date +%Y-%m-%d`.`pwd | sed 's,^\(.*/\)\?\([^/]*\),\2,'`.`git branch | grep "*" | sed "s/* //"`/restore.sh

    Make the restore script executable: chmod u+x ~/untracked-git-backup-`date +%Y-%m-%d`.`pwd | sed 's,^\(.*/\)\?\([^/]*\),\2,'`.`git branch | grep "*" | sed "s/* //"`/restore.sh

    Lastly, the magic, compressed into one line that will stop if any command does not report success: a='untracked-git-backup-'`date +%Y-%m-%d`.`pwd | sed 's,^\(.*/\)\?\([^/]*\),\2,'`.`git branch | grep "*" | sed "s/* //"`; git ls-files -o --exclude-standard -z | cpio -pmdu ~/$a/ && git clean -d -f && echo "(cd ~/$a/; find . -type f \( ! -iname 'restore.sh' \) | cpio -pdm `pwd`)" > ~/$a/restore.sh && chmod +x ~/$a/restore.sh; unset a


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    Permalink: 20130515.git.untracked.mess