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Mobile WiFi NAS on Raspberry Pi with TrueCrypt

Arif — Sun, 01 Jun 2014 04:23:18 +0000

Mobile NAS sounds like an idea worth waiting for to run on my mini Raspberry Pi Model A. Unfortunately, it only took me a while, before abandoning it. I’ve waited since writing about Raspberry Pi USB problem, that is to finally cut the backfeeding power line from the el cheapo powered USB hub. There comes new problem afterward, my “big storage” ―a Seagate® Backup Plus Slim Portable Drive, shipped with no bulky power supply line― can’t be mounted. Silence soon follows rotating motor sound a while after plugging-in. I’ve tried both ext3 and NTFS (using ntfs-3g) without luck. Later, as benchmark whether it is USB power in question, I try to connect the same set of el cheapo USB hub plus external power to laptop, and it works, leaving me stranded with other issue (is it USB 3.0? 256MB of the Model A? Anything?). I must say that it isn’t completely not-working as the USB hub set can mount with USB to IDE converter and my old internal hard disk (noting that there shouldn’t be similar power issue this way). If only it weren’t for the AC power adapter and large size, this is Mobile NAS; beats me.

Battery power bank, WiFi USB stick, and thumb drive

I then turn away to motor-less small storage, a 32 Gigs USB thumb drive so I can move on to other concern: on-the-fly encryption. Hence, I follow instructions to install True Crypt on Raspberry Pi. After unpacking of wxWidgets-2.8.12.tar.gz and TrueCrypt 7.1a Source.tar.gz in place, putting header files from pkcs-11-cryptoki2.20, and then install libfuse-dev, the following make will require long time:

$ export PKCS11_INC=/usr/local/src/truecrypt/pkcs/
 
$ make NOGUI=1 WX_ROOT=/usr/src/wxWidgets wxbuild
Configuring wxWidgets library...
Building wxWidgets library...
/usr/src/wxWidgets/src/common/string.cpp:84:39: warning: ‘wxEmptyString’ initialized and declared ‘extern’ [enabled by default]

$ make NOGUI=1 WX_ROOT=/usr/src/wxWidgets wxbuild
Compiling Buffer.cpp
Compiling Exception.cpp
Compiling Event.cpp
...
../Crypto/Aeskey.c:527:25: warning: operation on ‘ss[7]’ may be undefined [-Wsequence-point]
../Crypto/Aeskey.c:527:25: warning: operation on ‘ss[7]’ may be undefined [-Wsequence-point]
../Crypto/Aeskey.c:527:25: warning: operation on ‘ss[7]’ may be undefined [-Wsequence-point]
...
Converting Language.xml
Compiling Resources.cpp
Linking truecrypt

I created the TrueCrypt volume separately via its desktop GUI with ext3 file system to then mount it in Pi to a configured Samba share. As pointed out in a post, the following changes are added to smb.conf

...
wins support = yes
...
[pitruecrypt]
   comment= Pi Truecrypt Volume
   path=<the mount path of the USB thumb drive TrueCrypt volume>
   browseable=Yes
   writeable=Yes
   only guest=no
   create mask=0777
   directory mask=0777
   public=no

and then user-password are entered via interactive command.

For mobility, I already had the Pi as WiFi access point using hostapd (check these steps) and power bank, so it’s now matter of performance. In the case of rsync, initial sync of some 1,500 items totaling in 1 Gig size elapses in approximately the same 12 minutes of time compared to one bulk file of the same size. Of course, over the next incremental sync, it only takes less than a minute for the thousand items to just update slight differences.

Security

Back to security, there surely risk by opening Samba share to mounted TrueCrypt volume. But, for me it would be practically manageable (cross my finger). There is more concern to the fate of TrueCrypt after it is being closed in such a weird way, given that last audit finds nothing severe. Anyway, I found brute force tool, but no critical attack exists currently, unless e.g. it stays powered on and mounted, the person gain physical access. Beats me again.

Tagsistant On Production (2)

Arif — Sat, 27 Mar 2010 13:08:40 +0000

I’ve been waiting for someone to release a special-GUI-file manager to support Tagsistant. I decided not to wait and try out existing straightforward implementation (see previous post). I create a directory named tags inside my home and add an item on desktop session startup in System > Preferences > Startup Apllications containing this command

tagsistant -o allow_other -o umask=0022 -o uid=1000 --repository=~/.tagsistant ~/tags

Prior to that, I change owner from root to me on

$ ls -l /etc/fuse.conf
 
-rw-r----- 1 arif arif 215 2010-02-09 11:20 /etc/fuse.conf

and uncomment the user_allow_other of that config.

Running Tagsistant will add this mount

$ mount
...
gvfs-fuse-daemon on /home/arif/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=arif)
tagsistant on /home/arif/tags type fuse (rw,nosuid,nodev,allow_other,user=arif)
 
$ df -k
Filesystem           1K-blocks      Used Available Use% Mounted on...
tagsistant           123593820  91720380  25595240  79% /home/arif/tags

Original file storage in this config is in ~/.tagsistant/archive/ and tagging structure in SQLite format is kept in ~/.tagsistant/tags.sql.

Serious Performance Drawback

I can use Nautilus or Krusader (basically any file browser) to access the tagged files but performance really drops when tags.sql reaches some 160MB. I don’t have time to look further and skip the chance to use it any longer in “production”.

Tagsistant (1)

Arif — Wed, 09 Sep 2009 06:09:59 +0000

Installation of tagsistant requires SQLite and FUSE, in Ubuntu they are satisfied as libsqlite3-dev and libfuse-dev (which will also requires libselinux1-dev and libsepol1-dev). A series of configure, make, and make-install will fail during the make-install. /usr/local/share/pixmaps must be created first before running

$ sudo make install

After that I test tagsistant to organize /data/tags/

$ tagsistant /data/tags

The tagging works as expected but not too handy since no browser GUI is embedded. It is just like browsing through multiple OR and AND folders.

The installation process will also install tagman (a tag manager GUI) if libgtk2.0-dev and libglib2.0-dev are installed.

Mount with fstab and UUID

Arif — Fri, 05 Jun 2009 08:16:22 +0000

Check UUID:

$ blkid
 
/dev/loop0: TYPE="squashfs"
/dev/sda1: UUID="46E439E9E439DBBD" LABEL="SYSTEM" TYPE="ntfs"
/dev/sda5: LABEL="DATA" UUID="0686-FAFA" TYPE="vfat"
/dev/sda6: UUID="4ddd1e8c-e2e2-4397-838b-ea953e0a7795" SEC_TYPE="ext2" TYPE="ext3"
/dev/sda7: TYPE="swap" UUID="9be4f92e-4f22-41f4-9aee-1c93f9cdf6ac"
/dev/sda8: UUID="6a969f33-240b-440c-9a43-e68f8b28fd19" SEC_TYPE="ext2" TYPE="ext3"
/dev/sda9: UUID="d7aac664-c177-46aa-be67-40aad4d3f129" TYPE="ext3" SEC_TYPE="ext2"
/dev/sda10: UUID="36cdb4cb-351b-4f47-9c24-64a9e80c826b" TYPE="ext4"

$ sudo vol_id -u /dev/sda7
9be4f92e-4f22-41f4-9aee-1c93f9cdf6ac

Put it in /etc/fstab to mount the device at boot.

# /etc/fstab: static file system information.
#
# Use 'vol_id --uuid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
#                
proc            /proc           proc    defaults        0       0
# / was on /dev/sda10 during installation
UUID=36cdb4cb-351b-4f47-9c24-64a9e80c826b /               ext4    relatime,errors=remount-ro 0       1
# /home was on /dev/sda9 during installation
#UUID=d7aac664-c177-46aa-be67-40aad4d3f129 /home           ext3    relatime        0       2
# /home moved to /dev/sda8 using ext4 file system, /apps uses previous /home in /dev/sda9
UUID=6a969f33-240b-440c-9a43-e68f8b28fd19 /home           ext3    relatime        0       2
UUID=d7aac664-c177-46aa-be67-40aad4d3f129 /apps           ext3    relatime        0       2
# swap was on /dev/sda7 during installation
UUID=9be4f92e-4f22-41f4-9aee-1c93f9cdf6ac none            swap sw              0       0
# /dev/sda5
UUID=0686-FAFA  /media/sda5     vfat    defaults,utf8,umask=007,gid=46 0       1

The sixth field <pass>, is used by the fsck program to determine the order in which filesystem checks are done at reboot time. The root filesystem should be specified with a <pass> of 1, and other filesystems should have a <pass> of 2.