Posts Tagged ‘debian’

backtrack to install a backtrack

Thursday, September 9th, 2010

BackTrack is your daddy.
BackTrack accepts no compromises, yet it is all compromising.
Because really, when is the last time you *didn’t* need those auditing tools? That penetration suite? Total privacy to break other people’s privacy? All that and a packet of crisps wrapped with razor sharp menus – it’s the kind of stuff you can only dream of on core. And I hear Fedora Core is the shitzitz now, adopting new [1] and exciting[2] features. Oh hey debian doesn’t have binary deltas for packages *yet* [3], but we’ve been talking about it way longer than those dudes have.

Anecdtotally, I spilled a glass of water on my laptop the other day. Naturally, the glass went half empty in an instant: my poor lovely x41, I screamed. As it turns out the laptop casing made sure all the water was rather cleverly funneled into the x41′s only 1.8″ harddrive, which proceeded to go completely bananas (due presumably to rust, because clean water doesn’t conduct, right?). The data? I believe trusty old dd_rescue did rescue at least part of it, but I then misplaced the image file somewhere.

The system?
It was a thrifty, untrusted yet trusty Windows XP install that I’d been keeping on there on the mercy of actually booting every time since I bought the machine despite having been licked by more than its fair share of virii, malignant updates and accidental hard resets. Most of the programs I ran were portable[4] versions so all I lost were some documents and lots of music[5].

The hardware?
I disassembled and metricuously dried every little component, and in the end only the disk drive was bust. The 1.8″ IDE drive that is impossibly ridiculously expensive to replace (5$ per GB? What the foo? Shut up!). Still, I needed the laptop so I exploded booting from USB. Despite (misguided?) efforts I haven’t bloody well been able to boot windows off USB, so I bootstrapped BackTrack 3 instead and bob is your uncle.

I mean really, I think I had that thing running like that for three months before I started missing stuff like apt. Didn’t really mind starting fresh every boot, I even invented a whole little schpiel for getting online as fast as possible, none of that Network Manager madness.
Persistent settings are all right in BT3 but booting into RAM is a lot more fun. After the first 3 seconds of boot you can pull the USB plug, everything goes zippety fast and your footprint is nada. Only thing that can get your ass is a cold boot attack.

BT3 is real cool and still a good recommend if you want to wardrive and do proper wifi phreaking due to the embedded injection drivers, but in the end I wanted new libs, a decent compiler and window dressing, and so I rolled BackTrack 4.

Granted, kde sucks, but if I cared enough I’d switch to openbox or something awesome in like 4 minutes. These days all I need is a shell and a browser.

For those of you fortunate enough to have a harddrive, BT4 ships with an install script to turn your system into a permanent BackTrack fixture. It’s based off Ubiquity, but dd’ing off the USB and onto your disk drive might be better if you’re interested in being able to boot your system into RAM, well I dunno because you want to do some advanced powersaving[6], or want to kill your system without worrying about unclean shutdowns, or want to maximise the life span of your solid-state device by nearly never writing to it.

For my own part there was a happy ending on DealExtreme, as they ship IDE44 to CompactFlash interfaces that fit in the x41 1.8″ bay… which leads to a whole slew of unexplored possibilities thaaat (drum rolls) I will explore in the next installment of how to break your machine.

BackTrack 4 R1 has released :-) [6]. Anyone know where I can score the BlackHat Edition?

[1] http://fedoraproject.org/wiki/Releases/FeaturePresto
[2] http://fedoraproject.org/wiki/Features/systemd
[3] http://samba.anu.edu.au/rsync/rsync-and-debian/rsync-and-debian.html
[4] http://portableapps.com/
[5] http://drownedinsound.com/community/boards/music/4179554
[6] http://kacper.blog.linpro.no/archives/13
[7] http://www.backtrack-linux.org/

pulse audio: an experiment in social engineering

Tuesday, September 7th, 2010

The title about sums up the sentiments on the topic in my department.
What’s the use case for pulse audio?

Apparently, pulse audio is:
* configurationless consumer audio
* something that sits between you and your sound
* a replacement for ESD
* necessary for normal printer(!) operation
* cross-platform and works on windows
* really really complex
* the shit when you want less usability
* the bomb when you want less security
* not really competing with jack
* really good at marketing itself
* on by default in most current distros.

The cure:
apt-get remove –purge pulseaudio\*
yum remove pulseaudio

tune2fs and green disks

Thursday, August 5th, 2010

Hey folks,
old news I’m sure, but if you get tempted into buying the new WD Caviar “Green Power” disks there is something you need to know about them: they fake 512-byte blocksizes while in reality having 4096-byte blocks! The move to 4K blocks is reasonable considering we just busted the 2 terabyte barrier, but the disk firmware is faking 512-byte blocks in the name of compatibility (read: so windows xp won’t shit itself).

Unfortunately, running in bs512 mode makes the disk exactly 3x slower than it should be!
The fix: line up your partitions at 4k boundries, so start partition one at block 64, 1024 or even 2048 (the win7 start block) not the default, 63, in most partitioning software. Start fdisk with the -u parameter and carefully specify the start block. In gparted you’ll have to unhook the “snap to cylinder boundries” checkbox, and then I suppose you could even move a partition to the right block, but expect this to take an inordinate amount of time!

On a related note, fsck’ing an ext filesystem on boot is a drag, and fsck’ing 2TB file systems is a huge drag. Sure you should be running the fsck but it has a nasty tendency to happen on your workstation precisely when you can’t afford the extra 5 minute delay!

I bump the default 10 mounts count to 0 (disabling mount count fscking) and auto-fsck my disks every 99 days, staggered so not all disks get checked on the same day. Do this with the tune2fs command:

wasp:~# tune2fs -c 0 -i 99d /dev/sda1
tune2fs 1.41.12 (17-May-2010)
Setting maximal mount count to -1
Setting interval between checks to 8553600 seconds

out.

PS I recently managed to achieve sustained throughputs of 110MB/s with these WD disks and properly aligned partitions:

7516192768 bytes (7.5 GB) copied, 68.4392 s, 110 MB/s
115+0 records in
114+0 records out

yes that’s disk-to-disk with ext4 and one large file, no fragmentation.

PPS the defaults have nowadays changed to 120 days and 39 mounts, to which I say -1 mounts is better anyway!

edit: Now that your files are aligned, you can specify a block size to mkfs as well, which might avoid unaligned fragments: mkfs.ext4 -b 4096 -L gigantor -O sparse_super /dev/sdb1

CPM: Reliable multiuser password management

Monday, August 2nd, 2010

Sup all,
summer is drawing to a close and vacation is definitely over, but I for one welcome the chance to think and act again. Some time ago our managed services department started complaining about various shoddy password management solutions. Truth be told we already had a good solution, CPM (“Console Password Management”) but the software had fallen into disrepair due to seldom and untidy updates from its author. A new maintainer was desired and a project to fix the software was decreed and the result fell into my lap so to speak.

What sets CPM apart from other password management solutions is that it supports multiple users and goes to great lengths to keep your passwords secure while at the same time being very simple in its design: CPM locks its XML-formatted hierarchical password database in non-swappable private memory (so your passwords don’t get written in cleartext to disk while swapping), and encrypts the database with an arbitrary amount of GnuPG public keys.

All this makes CPM quite nice for storing and sharing secrets in a nice curses-based searchable console interface.

For the longest time I’ve been keeping the hundred-odd passwords I can’t remember on notepads and in random text files, thinking that surely I should start employing some sort of password management before I go crazy or my passwords leak. The congruence of my wishes with the scope of this project, so I picked up CPM and gave it a little love, and the result can be found at

GitHub CPM with CPM packages for debian in the downloads section.

CPM crash course

Requirements: Gnu Privacy Guard, and a GPG keypair.

First, install CPM:

dpkg -i cpm_0.25~beta-2debian2_amd64.deb

Then, create a password database, adding your key to the recipient list when prompted.

create-cpmdb

Then, use CPM from the console:

cpm

CPM should now ask you for you GPG key password and display an empty database.

CPM is controlled with the arrow keys, Enter and some control keys.
Hitting Control-H will bring you to the Help screen which explains the control keys.

By default CPM organises your passwords in a structure of hosts that have several services which may have one or more users. Hosts, services, users and passwords are nodes in the tree and a node is added by hitting Control-A and given an appropriate name.

For instance, if I were to add a password ch1ckens0up to user lolarun on the wiki service of host fragglepop.info, I would create the following node structure:

  host:fragglepop.info
      \-->service:wiki
              \-->user:lolarun
                      \-->password:ch1ckens0up

Of course there is no need to follow this anal layout, and you may even change the node structure by editing the template names in CPM by hitting Control-N or modifying the /etc/cpmrc config file.

To have CPM generate a random password for you, hit Control-P.
Your changes are not saved unless you hit Control-W or quit the program by hitting ESC enough times. Quitting through Control-C will not save the database.

Future work includes pushing the package into Debian.

What you don’t get (yet) is a GTK-based GUI, or a wrapper to pull the password database out of GIT and commit it again after modification nor integration with gpg-agent, probably (?) due to a bug in gpgme.

Enjoy this lovely piece of software and leave a comment after testing it!

PRADS 0.2.0 hits release

Monday, June 21st, 2010

PRADS – the Passive Realtime Asset Detection System has reached release with codename: “our two cents”.

It’s been far too long since last release and many things have happened that we thought we would share with you.
First off, PRADS has been rebuilt from scratch to handle high throughput and should work nicely on those fat pipes out there. This means it operates a little differently on the command line.
Our tool is now quite easy to use and has support for many more signature methods.

Changelog for prads 0.2.0-1
* PRADS release 0.2.0
* SYN,SYNACK,ACK,FIN,RST, IPv6, service, client, UDP, ICMP, ARP support
* added and fixed many signatures
* log to prads-asset.log
* eat pcaps (-r file.pcap)
* dump statistics on exit
* wirefuzz script
* prads2snort and other fun tools
* better IPv6 support
* better OS guessing
* awesome memory usage and stability
* l337 optimizations for high thruput
* code refactoring, cleanups & bugfixes and more

Quick start:
root@machine# prads -D
[*] Running prads 0.2.0
[*] Using libpcap version 1.1.1
[*] Using PCRE version 7.8 2008-09-05
[*] OS checks enabled: SYN SYNACK RST FIN ACK
[*] Service checks enabled: TCP-SERVER TCP-CLIENT UDP-SERVICES ARP
[*] Device: eth0
[*] Daemonizing...

To see the raw asset log file:

root@machine# tail -f /var/log/prads-asset.log
asset,vlan,port,proto,service,[service-info],distance,discovered
84.24.154.213,0,1268,6,ACK,[65392:118:1:0:.:A:Windows:XP],10,1277044697
109.87.38.106,0,56393,6,ACK,[16425:114:1:0:.:A:Windows:XP],14,1277044697
192.168.2.43,0,38359,6,SYN,[S4:64:1:60:M1460,S,T,N,W7:.:Linux:2.6 (newer, 7):link:ethernet/modem:uptime:2630hrs],0,1277044698
192.168.2.43,0,48065,6,ACK,[54:64:1:0:N,N,T:ZAT:Linux:2.6:uptime:2630hrs],0,1277044697
76.99.73.67,0,55834,6,ACK,[33069:48:1:0:N,N,T:AT:Linux:2.4(newer)/2.6:uptime:307hrs],16,1277044697
65.191.159.39,0,48747,6,ACK,[259:114:1:0:N,N,T:AT:unknown:unknown:uptime:20hrs],14,1277044697

Remember that ACK mode is and always will be rather unreliable.

To get a better view of the detected systems, run the following command:

prads-asset-report | less
13 ------------------------------------------------------
IP: 109.87.38.106
OS: Windows Server 2008 (R2 Standard 64-bit) (60%) 1
[..crop..]
104 -----------------------------------------------------
IP: 192.168.2.43
OS: Linux 2.6 (newer, 7) (100%) 3
MAC(s): 00:DE:AD:BE:EF:2F (2010/06/20 16:39:00)

Port Service TCP-Application
80 CLIENT Mozilla/5.0 (X11; U; Linux x86_64; en (US) AppleWebKit/533.4 (K
HTML, like Gecko) Chrome/5.0.375.70
80 CLIENT @www
80 CLIENT Mozilla/5.0 (X11; U; Linux x86_64; en (US) AppleWebKit/533.4 (K
HTML, like Gecko) Chrome/5.0.375.70
443 CLIENT TLS 1.0 Client Hello
443 CLIENT TLS 1.0 Client Hello
3218 CLIENT rtorrent/0.8.6/0.12.6
6667 CLIENT @irc
6667 CLIENT @irc
6667 CLIENT SSL 2.0 Client Hello
50005 SERVER Bittorrent
50005 SERVER Bittorrent

Port Service UDP-Application
53 CLIENT @domain
53 CLIENT @domain
123 CLIENT @ntp

105 ------------------------------------------------------

[..snip..]

Packages are available for debian and ubuntu, for everyone else there is source.
Get PRADS now!

Report issues and feature requests to: http://github.com/gamelinux/prads/issues

For suggestions, help, contributions and general banter go to the PRADS mailing list.

brilliant fools – hackers update

Monday, March 1st, 2010

cracks are on the rise. so are hacks, and I haven’t posted a thing since December. So what’s up with you?

Good news is that Con Kolivas might have managed to defeat his carpal tunnel and swallow his spite for kernel dev elitism, and is again churning out solid kernel code to improve desktop usability – which the kernel devs aren’t too interested in – something he is quite right to say!

Hopefully ubuntu will pick up CK’s scheduling patches, because they are uber and with ubuntu’s momentum they might topple the stack. Too bad their kernel team can’t follow the churn. Wish I had time to compile it for you or even post some interbench stats with pretty graphs, but there is a BFQ PPA available already so you can test it out on your ubuntu or debian machine. Bonus? Some random dudes wrote a simple IO scheduler which is included there. Ain’t that reasonable?

All that at least until we have time to write our own OS which gets rid of all suckage, is super flexible and of course incorporates all our favorite patches.

Valgrind is pretty neat, and with that we have working stray acks in PRADS, the stealthy host and service detection system. More features and even a new release might come soon, which is to say – when it’s ready. In the mean time I welcome you to try breaking it in any and every way possible.

Also, if everything you do is motivated by monetary gains then you sir are a shame to the human race. Go back to step 1 and have a good day now.

kernel coolness, finally!

Thursday, November 5th, 2009

Many things worth blogging about are happening lately! In fact, so many things that there is not enough time to blog about them. Ah, where to begin!

Quickly now:

PRADS

Ebf0 and myself had a lecture about our fine host detection application at Dagen@IFI (Institute for informatics, UiO). Presentation available here, at least until we upload it to the project website.

We now know that our Proof of Concept is k00l and Ebf has started the high-performance C implementation.

Kernel hacks

Did you know you’re missing out on cool kernel features? Well, yes you are. Here are some of them:

  • grsecurity : Better security in linux! Fixes thousands of attack vectors for desktops and servers alike
  • compcache: compressed memory swap might sound counter intuitive, but memory is lightning fast compared to disk, and you can cram more apps into compressed memory!
  • nilfs: Every wished you hadn’t deleted that file 5 seconds ago? Or wasted an hour waiting for a fsck? Log structured file systems scream write performance. And NILFS aids in data recovery too, as it’ll take automatic snapshots of your data every synchronous write. Very sweet.
  • reiser4: Don’t get me started. This is still not reached mainline. Hans be damned. However, reiser4 is still the fastest file system around.
  • ++++ low-latency, preemptible, tickless system, loads of hardware support and lots more!

The upshot?

The -lied patchset is back!

I now track Ubuntu karmic git and I provide i686 packages:

Add the following to your /etc/apt/sources.list :

deb http://www.cs.mcgill.ca/~kwysoc/debian/binary ./

then install the package:

# add the archive key:

gpg --recv-key 089ac586 && gpg --armor --export 089ac586 | sudo apt-key add -

# update package database:

sudo apt-get update

# install the kernel package

sudo apt-get install linux-image-2.6.31.3-lied-grsec-dirty

# check grub or lilo and then reboot into the kernel!

amd64 binaries are coming as soon as I get a chance to compile them. For now grab the karmic git, the patchset and .config and roll your own :-)

What else?

Bifrost is coming along, and might be close to a release soon, and

Multiframe needs a new client release (which I am w0rking on)

oh and I’ve made an

auto-migrate from ISC dhcpd to dnsmasq by script

…with my quick and dirty perl f00 : dhcpd2dnsmasq.pl.

Be mindful that it is best for those with a lot of host definitions, and does not support all the ISC syntax out there.

The script is interesting because it consicely illustrates how to make a simple but powerful parser with the minimal amount of lines (and fuss) using the AND-OR Waterfall method.

Honk and Drop me a comment if you like / hate / fake it~!

xtend your battery so y ou can GO ALL NITE

Monday, September 14th, 2009

K3ep going all n1te just like all that sp4m c0ming in through your mailbox.10 watts, it's a new record!

10 watts, it's a new record!

From joke to revolver as we say, I’ve noted that many of you find hacking away from power sources quite useful. Here’s how to keep at it longer with low power.

(more…)

never ask for root again

Monday, August 17th, 2009

just a short note to all of you:

linux is not secure. Passwordless root is here :-*

Yes, it has been published elsewhere, but I’ll do mine to push this meme to you: there can be no “untrusted local users” nor do I believe that your services aren’t exploitable.

Two seconds later I have root on your box.

Despite LSM. Despite SELinux. Despite jails and virtualization. Despite all your assumptions.

You will need some very fine security gents and a little of your own smarts to secure your nets. Call us :-)

The best link on this issue so far has been:

cr0: bypassing linux with null pointer

Do you want security? Go run carpal-tunnel-inducing OpenBSD, swell swell if only it smelled well FreeBSD, or, *drum rolls*

drop-in up-to-date secure and invulnerable grsec kernel for ubuntu and debian

Only disadvantage I can see is that they don’t provide amd64 and desktop builds.

Dilligence and perseverence is the path to victory,
and although paranoia may not be the path to safety
noone should leave their front door open.

In other news, and probably a little lame for those of you coming thru the planet feed, security.vcl is here – properly used, understood and abused it could save you some worries, making sure no “untrusted user” went “local” in the first place.

Also, tell your friends: there is a Facebook virus about. It sends links to you from your friends accounts. If you click on the link, you too will be sending your friends links.

Yeah, I know, that sounds like what I do on facebook all day. Except the difference is you don’t know you’re sending links.

So watch out.

And tell your less savvy friends.

how to break your head : try linux compilination

Wednesday, July 29th, 2009

I’ve recently started compiling my own kernels again. Some people ask me why I’d ever want to do this – a valid question, since anyone who’s done it knows a time-consuming hassle best left to the distro packagers and really nerdy people with too much time on their hands. Other people will give a blank face and ask “What is a Conpiling?” To these other people: this article is not for you, it will only serve to confuse that pretty little head of yours. If you know what ‘a compiling’ is, you may proceed. I don’t provide references; I banter them. Google your friend, pluckum.
\
Still, I am not here to discuss the reasons for compiling your own kernel – these are all too obvious to the initiated and completely uninteresting to anyone else. I’m more interested in the reasons why my friends, collegues and I have *stopped* compiling our own kernels – despite some of us enjoying at least a compile a day (or ten!) for periods of time in the past. Only the gentoo rice boys remain, steadfastly compiling everything in sight despite snide comments about mean time between upgrades and ridicule about their USE_FLAGS selector GUIs.
\
Why don’t we compile anymore?
There is no stable upstream branch. In my own experience this has had direct consequences for the stability and quality of point releases.
Years after Linus’ bitkeeper schism, the SCO slimeballing and the death of the stable branch, we can look back and say that aye, we have a better audit trail and development has scaled through the roof. We have more kernel features than ever, and an astounding rate of patches make it into mainline every day.
\
These amazing developments are a long shot away from the linux dev process back in the days of 2.2 and 2.4, but there is a dark side to these developments.
Regressions are no longer the domain of the bleeding edge, the -mm or -ac trees, -alpha and -rc releases for the adventurous, masochistic or desperate. Common things. Getting bitten by that local sexploit and being too embarassed to tell your friends about it. Software suspend used to work fine. The graphics card did not crap itself on the last point release, but at least my NIC doesn’t get bricked in this one. The wifi keeps screwing with you, but you don’t know if you should blame Ubuntu, Intel or Linus. On the internet noone can hear you scream.

\

Elitism is rife on the LKML, and more pointedly, in the mainline patch process. Who knew NIH would be such a big problem in an open source project? Admittedly, it is the largest and perhaps the most ambitious open source project of all, with all eyes on target, a million uses and powerful market forces pulling the project this way and that. Linux has long ago outgrown the boy’s room, the hacker dungeon and its academic roots. Most kernel patches that get into mainline are pushed there by large hardware and software vendors. Many kernel hackers hack the kernel on their day job, earning an engineer’s living.
\
Linux has reached the Enterprise in a big way. The system runs and is optimized for Big Iron. The desktop is “good enough”, say the kernel hackers. Latency is fine for our uses, and those squeaky audiophiles should shut up and fork. Indeed they did, as embedded, realtime and audio people have all collectively decided to jump off the wagon.
Out-of-tree kernel hackers already know where the lay is at. After years of pushing the same genious useful patchsets they are sick of cleaning up, splitting out, documenting, backporting, forward porting only to discover that noone read their patch. Maybe they will be lucky, their ideas bastardized overnight into someone else’s pet project, far more likely to succeed once it is Invented Here(tm).
\
It’s not all bad: we want and need to trust the people that push stuff into the kernel. Who are you to think that you can do it better than them? They are doing their job, they do it well, so what if they all meet for beer and virgin sacrifice after hours, so what if there is no free seating in their society? Fork your own.
\
Weiging in at 800MB uncompressed, the Linux source is a behemoth. Counting only source, headers and assembly, there are 35,000 files in the linux kernel, with 10,667,648 lines of source code. This code is metriculously organized, not only into systems, subsystems and modules, but into domains of responsibility. Hey, if you’ve ever managed a large software project you would know how annoying, how encroaching it is when someone start fiddling with your private bits.
\
On the other hand, linux has lost a lot of great contributions and spurned a lot of marvelous people because of this elitism. OpenMosix israeli clustering, reiser4 the murderous file system, software suspend 2 the ‘it just works’ approach, page-in-from-swap, CK’s desktop efforts, the two kernel monty carlo and process snapshotting are only few of the projects that failed to sufficiently influence the core developers, some of them even year after year.
It can be argued that despite the patches not making it to mainline some of these ideas did find their way into the minds of the gitmasters and found other implementations on technical merit alone. To me this defeats the whole purpose of the open source model which drives technology by sheer speed. We’ve had a working, cleaned up, documented version of the patch for two years – and the feature doesn’t make the cut. This is too little too late.

\

Well, not everyone takes an interest in kernel politicking even if they follow the LKML or kerneltrap, and some people even like hitting bugs and fixing issues in their compiles, and trolling in epic flame wars. They too have left kernel compiling to other, more patient and masochistic people.
Maybe it’s because even grepping a single point release changelog is a major chore. The distro folks have gotten fairly good at kernel compiles; ubuntu ships a one-size-fits-all Just Works(tm) kernel, RedHat’s patchset has grown less offensive over the years and debian is and always was debian. Upgrades are relatively painless and usually somebody else already did the dirty work.
Linus Thorvald’s initial plan succeeded: by axing the stable/unstable tree he told the world that the responsibility for stability rests on the distributor. He also axed many hobbyists’ will to stay and play with new releases. I’d rather go play on milw0rm.

\

There are other compelling reasons not to roll one’s own: the number of configuration options has doubled over the past years, and most of these new options are not relevant to the hobbyist use case. Development not only in the kernel source but in the toolchain (gcc) has caused compile times to soar. I remember proudly compiling 2.4 kernels on my K7 within 10 minutes back in 2001. Today it might take longer to compile the tree on my Centrino dual-core.
And there it is: we’ve suffered feature creep and bloat. After a long download, an hour or more of configuring, and many failed initial make runs, a generic compiled bzImage weighs in at about 3412 kB. This is a modular kernel, mind you. What happened to lean and mean 800 kB kernels?

Memory is cheap you say.
But minds are not cheap!

\

I’m announcing a contest: what’s the smallest stable useful kernel you can make for your platform? Remember, it should run on other machines and be useful, and the compile reproducible. Choose your own definition of useful, but do find a concrete definition. Use any tree and patchsets that turn you on. Bonus points for packaging so others can plug your kernel into their system. I’ll make your package available.
As a side contest I’ll take compile times along with bogomips numbers and your .config file for reference.

\\\

PS. Yahoo! internal IT sucks. Where’s the wifi? Running our own cables, canned XP images in a linux lab, packet loss. This aint no funky party. I guess they are too busy. Paranoia maybe. Things aren’t wonderful.