Monthly Archives: June 2016

Android

Backup Google Authenticator Database

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Two factor authentication is great – I wish everything would use it.   My personal 2FA (specifically TOTP)  mobile app is Google Authenticator.  It allows you to scan a barcode, or manually enter a 2FA initilization token, and gives you a nice display of all of your stored 2FA tokens, with a great countdown of the token’s expiration.  However, it does have one critical flaw feature:  You can’t export your accounts.

Let me re-state that:  Your 2FA tokens are locked away in your mobile device.  Without the device, you’re locked out of your accounts (Hopefully you created backup codes).  If your device becomes inoperable, good luck!

However, if you have root access to your device, you can grab the Google Authenticator database and stow it away for safe keeping by grabbing it from the following location on your phone:

/data/data/com.google.android.apps.authenticator2/

If you have ADB enabled, you can just run the following command:

 adb pull /data/data/com.google.android.apps.authenticator2

Keep this information very secure, as it can be used to generate 2FA codes for all of your accounts!

Microsoft Exchange

Exchange Dynamic Distribution Group Delivery Problems

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Consider the following:

An Exchange Dynamic Distribution Group has a valid recipient filter, and the filter generates the desired resultant set of recipients with the following PowerShell command:

Get-Recipient - RecipientPreviewFilter $(Get-DynamicDistributionGroup "name").RecipientFilter

However, when a user sends a message to the group, no messages are delivered, and the sender does not receive an NDR.

One possible cause of this issue is a property of the dynamic distribution group called RecipientContainer.  This is similar to the SearchBase attribute of the Get-ADUser cmdlet: it specifies the container in which to apply the RecipientFilter.  Therefore, the RecipientContainer must be the OU (Or a parent of) in which the desired users are stored.

More info here: https://www.corelan.be/index.php/2008/11/05/dynamic-distribution-lists-not-working-as-expected-0-recipients-during-mail-routing/

Linux

Troubleshooting OwnCloud index.php

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Sometimes OwnCloud includes “index.php” in the shared links.  It’s annoying and ugly.  Here’s some things to check:

  1. Is mod rewrite enabled in the apache config? 
    <Directory /var/www/html/owncloud/>
 Options Indexes FollowSymLinks MultiViews
 AllowOverride All
 Order allow,deny
 Allow from all
 <IfModule mod_dav.c>
  Dav off
  </IfModule>
 SetEnv HOME /var/www/html/owncloud
 SetEnv HTTP_HOME /var/www/html/owncloud
</Directory>
  2. Is the .htaccess correct?  The ###DO NOT EDIT### Section must contain this line (Generally the last line in the IfModule for mod_rewrite 
    RewriteRule .* index.php [PT,E=PATH_INFO:$1]
  3. .htaccess must also contain this block for the web app to generate URLs without “index.php” 
    <IfModule mod_rewrite.c>
  RewriteBase /
  <IfModule mod_env.c>
    SetEnv front_controller_active true
    <IfModule mod_dir.c>
      DirectorySlash off
    </IfModule>
  </IfModule>
</IfModule>

Those are my findings for making sure OwnCloud URLs stay pretty.

Linux

Unifi Controller on 16.04

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Steps to install the UniFi controller on Ubuntu 16.04.  Note that the package depends on JRE7, so we must add the ppa repo to apt.

echo "deb http://www.ubnt.com/downloads/unifi/debian stable ubiquiti" > /etc/apt/sources.list.d/ubnt.list
apt-key adv --keyserver keyserver.ubuntu.com --recv C0A52C50


sudo add-apt-repository ppa:openjdk-r/ppa
sudo apt-get update


sudo apt-get install unifi
Linux

Expand Ubuntu LVM

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Expand an existing Ubuntu LVM without creating additional partitions, or adding to LVM VGs:

  1. Expand the physical device (VMware, HyperV, DD to a new physical device,  etc)
  2. Use offline GParted cd to re size the extended partition on which LVM lives
  3. In live OS, use parted “resizepart” to extend the logical partition inside of the previously re sized extended partition 
    (parted) resizepart
Partition number? 5
End? [268GB]? 1099GB
  4. reboot
  5. use LVM to resize the PV: 
    pvresize /dev/sda5
  6. resize the filesystem in the LV: 
    resize2fs

 

References: