ter Smitten's

A few months ago my N900 (touchscreen) died. Without a working touchscreen it proved to be impossible to operate it. Although I could have logged in via SSH unfortunately my WIFI and 3G were of 🙁 So there was no possibly to create an export of all my data. Fortunately I had a backup. The only problem was that the backup was just a set of zip files:

# ll
totaal 4,0M
-rw-r--r-- 1 lorem ipsum 1,1K sep 25  2011 applications.zip
-rw-r--r-- 1 lorem ipsum  678 sep 25  2011 backup.metadata
-rw-r--r-- 1 lorem ipsum 233K sep 25  2011 bookmarks.zip
-rw-r--r-- 1 lorem ipsum 2,2M sep 25  2011 comm_and_cal.zip
-rw-r--r-- 1 lorem ipsum 1,6M sep 25  2011 settings.zip

containing “raw” dumps of directories. Not particularly useful for transferring to a new phone…

After some searching I found a file called addressbook.db (in comm_and_cal.zip:/home/user/.osso-abook-backup/db/) which should contain my contacts (vcard data). I read that addressbook.db was a Berkeley DB (BDB) database file. Because I was learning Python I wrote a simple script to extract the vcard data from the database and write it as separate vcards (which are easy to import on other devices) to a folder.

I hope it useful for someone else and please comment my python skills 🙂

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys
import vobject
from bsddb3 import db

if len(sys.argv) != 2:
  print ""
  print "Usage:"
  print "%s [path to addressbook.db]" % sys.argv[0]
  print ""
  sys.exit(1)

fileName = sys.argv[1].strip()

addressBookDb = db.DB()
try:
  # Try to open db file
  addressBookDb.open(fileName, None, db.DB_HASH, db.DB_DIRTY_READ)

  cursor = addressBookDb.cursor()
  record = cursor.first()

  # Fill a list with vcard strings from db 
  vCards = []
  while record:

    # Get vcard string and correct line endings
    vCardString = record[1].replace('\x00', '\r\n')
    vCards.append(vCardString)

    record = cursor.next()

  # Write vcard strings
  for vCard in vCards:

    parsedVCard = vobject.readOne(vCard)
    
    # Not all entries have a n(ame) attribute
    if hasattr(parsedVCard, 'n'):
      vCardName = str(parsedVCard.n.value).strip()
      
      # Open vcard for writing
      with open('vcards/%s.vcf' % vCardName, 'w') as fd:
        fd.write(vCard)
      fd.close()

except db.DBNoSuchFileError:
  print ""
  print "Error:"
  print "Could not open '%s'" % fileName
  print ""
  sys.exit(1)

References:

• Nokia n900 mobile forensic cheat sheet

Recently I needed to “rename” a user (mischa_new -> mischa-new). Personally I find changing only the name a bit ugly and confusing. So this is how I addressed it:

Change username

usermod -l mischa-new mischa_new;

Change home directory (move)

usermod -d /home/mischa-new -m mischa-new;

Change group name

groupmod -n mischa-new mischa_new;

Personally I find Gnome’s `Recent documents` feature quit annoying. In earlier versions I always disabled it like this. Unfortunately that didn’t work anymore… Apparently .recently-used.xbel has moved to a new location (thanks ade). It is now in ~/.local/share/recently-used.xbel. So this should do the trick:

rm ~/.local/share/recently-used.xbel -Rf;
mkdir ~/.local/share/recently-used.xbel -p;

Simple Network Management Protocol (SNMP) is an “Internet-standard protocol for managing devices on IP networks.”

Version 3:
Although SNMPv3 makes no changes to the protocol aside from the addition of cryptographic security, it looks much different due to new textual conventions, concepts, and terminology.

SNMPv3 primarily added security and remote configuration enhancements to SNMP.

Security has been the biggest weakness of SNMP since the beginning. Authentication in SNMP Versions 1 and 2 amounts to nothing more than a password (community string) sent in clear text between a manager and agent. Each SNMPv3 message contains security parameters which are encoded as an octet string. The meaning of these security parameters depends on the security model being used.

SNMPv3 provides important security features:

• Confidentiality – Encryption of packets to prevent snooping by an unauthorized source.
• Integrity – Message integrity to ensure that a packet has not been tampered with in transit including an optional packet replay protection mechanism.
• Authentication – to verify that the message is from a valid source.

Configuration:
In Ubuntu 10.04 I used these settings which were working fine but not exactly secure:

/etc/default/snmpd

# This file controls the activity of snmpd and snmptrapd

# MIB directories.  /usr/share/snmp/mibs is the default, but
# including it here avoids some strange problems.
export MIBDIRS=/usr/share/snmp/mibs

# snmpd control (yes means start daemon).
SNMPDRUN=yes

# snmpd options (use syslog, close stdin/out/err).
SNMPDOPTS='-LS4d -Lf /dev/null -u snmp -g snmp -I -smux -p /var/run/snmpd.pid 127.0.0.1'

# snmptrapd control (yes means start daemon).  As of net-snmp version
# 5.0, master agentx support must be enabled in snmpd before snmptrapd
# can be run.  See snmpd.conf(5) for how to do this.
TRAPDRUN=no

# snmptrapd options (use syslog).
TRAPDOPTS='-Lsd -p /var/run/snmptrapd.pid'

# create symlink on Debian legacy location to official RFC path
SNMPDCOMPAT=yes

/etc/snmp/snmpd.conf

com2sec ro default public
com2sec rw localhost private

group public v1 ro
group public v2c ro
group public usm ro
group private v1 rw
group private v2c rw
group private usm rw

view all    included  .1                               80
view system included  .iso.org.dod.internet.mgmt.mib-2.system

access public "" any noauth exact all none none
access private "" any noauth exact all all all

In Ubuntu 12.04 I couldn’t get things to work in the first place. Not with the default settings and not with the above. Looking at /var/log/syslog made it clear that SNMPD wasn’t able to locate the MIBs.

Nov 17 22:27:59 hades snmpd[1066]: payload OID: prNames
Nov 17 22:27:59 hades snmpd[1066]: /etc/snmp/snmpd.conf: line 143: Error: unknown payload OID
Nov 17 22:27:59 hades snmpd[1066]: Unknown payload OID: prNames
Nov 17 22:27:59 hades snmpd[1066]: /etc/snmp/snmpd.conf: line 143: Error: Unknown payload OID
Nov 17 22:27:59 hades snmpd[1066]: payload OID: prErrMessage
Nov 17 22:27:59 hades snmpd[1066]: /etc/snmp/snmpd.conf: line 143: Error: unknown payload OID
Nov 17 22:27:59 hades snmpd[1066]: Unknown payload OID: prErrMessage
Nov 17 22:27:59 hades snmpd[1066]: /etc/snmp/snmpd.conf: line 143: Error: Unknown payload OID
Nov 17 22:27:59 hades snmpd[1066]: trigger OID: prErrorFlag
Nov 17 22:27:59 hades snmpd[1066]: /etc/snmp/snmpd.conf: line 143: Error: unknown monitor OID
...
Nov 17 22:27:59 hades snmpd[1066]: Turning on AgentX master support.
Nov 17 22:27:59 hades snmpd[1066]: net-snmp: 33 error(s) in config file(s)

After some searching I was able to get it running by setting MIBS to UCD-SNMP-MIB in /etc/default/snmpd.

In order to get SNMPv3 running only some minor adjustments were needed. I ended up with the following settings (which I hope are secure :-), see last two references (in Dutch)):

/etc/default/snmpd

# This file controls the activity of snmpd and snmptrapd

# Don't load any MIBs by default.
# You might comment this lines once you have the MIBs downloaded.
export MIBS=UCD-SNMP-MIB

# snmpd control (yes means start daemon).
SNMPDRUN=yes

# snmpd options (use syslog, close stdin/out/err).
SNMPDOPTS='-LS4d -Lf /dev/null -u snmp -g snmp -I -smux -p /var/run/snmpd.pid'

# snmptrapd control (yes means start daemon).  As of net-snmp version
# 5.0, master agentx support must be enabled in snmpd before snmptrapd
# can be run.  See snmpd.conf(5) for how to do this.
TRAPDRUN=no

# snmptrapd options (use syslog).
TRAPDOPTS='-Lsd -p /var/run/snmptrapd.pid'

# create symlink on Debian legacy location to official RFC path
SNMPDCOMPAT=yes

/etc/snmp/snmpd.conf

agentAddress udp:161,udp6:[::1]:161

createUser internalUser  MD5 "mypassword3"
createUser cacti SHA "mypassword4" AES "passphrase4"

view   systemonly  included   .1.3.6.1.2.1.1
view   systemonly  included   .1.3.6.1.2.1.25.1

rouser   cacti

iquerySecName   internalUser
rouser          internalUser

defaultMonitors          yes
linkUpDownNotifications  yes

master          agentx

References:

• Simple Network Management Protocol
• Unknown payload OID
• Configuring SNMPv3
• snmpd not working (Ubuntu 12.04)
• HOWTO use SNMPv3 (UBUNTU)
• NCSC waarschuwt voor onveilige SNMP-configuraties
• ‘Tienduizenden Nederlandse instellingen kwetsbaar door snmp-probleem’

While applying some (550) changesets I needed some good tools to show me the differences between files and revisions.

The first one I found very useful was:

svn diff --diff-cmd diff -x -uw -r REV1:REV2 FILE;

which is even better in combination with colordiff:

apt-get install colordiff;
svn diff --diff-cmd diff -x -uw -r REV1:REV2 FILE | colordiff;

An other great tool is vimdiff, which starts Vim as usual, and additionally sets it up for viewing the differences between files. Here’s how I use it:

sudo apt-get install vim;
vimdiff -O -c 'set diffopt+=iwhite,filler' FILE1 FILE2;

Some of you will probably prefer Meld, which is a visual diff and merge tool.

To combine the powers of all three I created a simple (Bash) wrapper. It downloads two revisions (svn) of a file and compares them using a diff tool of choice:

#!/bin/bash
#
# set -x;
#
if [ -z "${1}" ] || [ -z "${2}" ] || [ -z "${3}" ]; then

  echo "";
  echo "Use the script as discribed below:";
  echo "$0 [ filename ] [ revision1 ] [ revision2 ] [ diff tool (optionally) ]";
  echo "";

else

  pid=$$;

  filename="${1}";
  revision1="${2}";
  revision2="${3}";
  diff_command="${4}";

  temp1="/tmp/${pid}.${revision1}.${filename}";
  temp2="/tmp/${pid}.${revision2}.${filename}";

  trap trap_function 0 1 2 15;

  trap_function()
  {
    if [ -f "${temp1}" ]; then

      rm "${temp1}";

    fi

    if [ -f "${temp2}" ]; then

      rm "${temp2}";

    fi
  }

  svn cat "${filename}" -r "${revision1}" > "${temp1}";
  svn cat "${filename}" -r "${revision2}" > "${temp2}";

  if [ "${diff_command}" == "vimdiff" ]; then

    vimdiff -O -c 'set diffopt+=iwhite,filler' "${temp1}" "${temp2}";

  elif [ "${diff_command}" == "meld" ]; then

    meld --diff "${temp1}" "${temp2}";

  else

    diff -uw "${temp1}" "${temp2}" | colordiff;

  fi

fi

Recently I needed to install PHPUnit to write some test for an application I was working on. Here I will describe how I installed it on Ubuntu.

First of all, you’ll need to install PEAR, which provides a distribution system for PHP packages, and is shipped with every release of PHP since version 4.3.0.

apt-get install php5-dev php-pear

Subsequently you’ll install PHPUnit through the PEAR installer. To do that run the following:

pear upgrade PEAR
pear config-set auto_discover 1
pear install pear.phpunit.de/PHPUnit

After the installation you can find the PHPUnit source files inside your local PEAR directory; the path is usually /usr/lib/php/PHPUnit.

Because deleting rules in UFW can be a little bit annoying this little trick will make your life much easier. Instead of using this syntax:

ufw delete allow 80/tcp

use this syntax:

ufw delete ####

where #### is the number of your firewall rule.

The numbers of your firewall rules can listed using:

ufw status numbered

A possible output could be:

Status: active

     To                         Action      From
     --                         ------      ----
[ 1] 80/tcp                     ALLOW IN    Anywhere
[ 2] 443/tcp                    ALLOW IN    Anywhere

If you want to make sure that cache/log files won’t show up when you commit, execute the following command inside your app directory.

svn propset svn:ignore "*" tmp -R

This will ignore the tmp directory (recursively)!

Ubuntu 12.04 LTS will be released on April 26 and supported until April 2017.

Updates I am looking forward to include:

• MySQL version 5.5.22
• APC version 3.1.7-1

and of course the 3.2.0.x kernel!

References:

• http://www.ubuntu.com/community/countdown
• https://wiki.ubuntu.com/PrecisePangolin/TechnicalOverview/Beta2#New_features_in_Precise

Sometimes you’ll have an error in your commit message or no message at all. If your repository is configured to accept changes to this log message after the commit is finished, you can “fix” your message remotely using svn propset. However, because of the potential to loose information, Subversion repositories are not, by default, configured to allow changes to unversioned properties—except by an administrator.

This is how your do it:

echo "Your corrected commit message" > message;
svnadmin setlog /home/projman/svn/site/ -r 4658 --bypass-hooks message;
rm message;

If your’re also using Trac your changes won’t show up in your “timeline“. To fix that make sure to resync your TracEnvironment:

trac-admin /home/projman/trac/site/;
resync 4658
exit

Everything should by fine now!

References:

• Bottled Text
• Version Control with Subversion