Truecrypt permissions issue

[arumiat]

So I've recently migrated from my MacOSX to Ubuntu.

However I'm having an issue with the permissions of the files I've brought across.

• created a Truecrypt container on my MacOSX (a while ago).
• works fine when moving this container and mounting it using Truecrypt on another MacOSX
• mounting it via Truecrypt (using the GUI) on Ubuntu 12.04 gives me only read permissions. I put in the correct Truecrypt password & my admin password to do this
• right-clicking the file I want to modify and going into the permissions tab under Ubuntu shows the owner as 501 - user #501. Owner has read and write permissions
• the group under this is dialout and is read only
• I obviously want write permissions on Ubuntu as well so I can modify the contents of my container ongoing
• I've checked the volume properties in Truecrypt, - it was NOT created as a read-only volume. When I mount the volume in Truecrypt for each session the 'Mount as read-only' option is NOT ticked

Can anyone please enlighten me as to how to get write privileges with the mounted container? Want to offload my Mac asap but too worried to do so before I've got all my encrypted docs working.
Thanks in advance

[arumiat]

So possible ways around this...
? use the chmod command to reset file permissions to read & write (either on linux or mac? http://www.macinstruct.com/node/415)

Any thoughts really appreciated

[cincinnatus13]

Yeah, sounds like you just need to chown it.

I might get confirmation from someone else before you tried this (as I've only used chown a few times) but the syntax is

chown username:username nameoffile

assuming of course that you are root.

This is the basic layout. Knowing it's a TC volume, I would assume you don't need the -r since it is seen as only one file by itself. This will change it though to your username and group (1000 by default I believe.)
Either cd into the folder or type the full path- /location/of/file/nameoffile.tc

[arumiat]

Thanks Cincinnatus13

I've ended up using the info from this article to open up a gksu nautilus window (giving me root access) and I'm going to use that to hopefully change the file-permissions for the main directory and all the directories & files 'underneath' it. I'm still terrified of using the terminal window.

However if I try and change the Owner, Group or Others drop down menu to my user running as root (gksu nautilus) it gives an error that it is a 'read-only file system'. I imagine then even with terminal the same problem would apply.

I'm wondering if there's a way to change the permissions on my Mac prior to transferring the files over to my Ubuntu system? Or whether it's the transfer of files via an external HDD that sets the permissions or something..

This is massively frustrating, any further help appreciated.

[varunendra]

However if I try and change the Owner, Group or Others drop down menu to my user running as root (gksu nautilus) it gives an error that it is a 'read-only file system'. I imagine then even with terminal the same problem would apply.

The highlighted part is the keyword here. What is the file system of the container?

Since you created it on MacOS, I think it may be HFS/HFS+. I'm not sure whether Ubuntu by default has write support for it or not. If not, you may just need to install hfsutils package.

If not sure, please show us the terminal (oh my.. ) output of -

mount

.. when the volume is mounted in truecrypt.

[arumiat]

I also tried transferring the Truecrypt file over using FAT32 on an external HDD, didn't make any difference.

[varunendra]

I also tried transferring the Truecrypt file over using FAT32 on an external HDD, didn't make any difference.

Didn't get it. Do you mean you copied the encrypted files 'inside the container' over to a FAT partition and they were still read-only? If so, that is purely a mounting problem.

If it was the truecrypt container itself, then again, the filesystem of the container is what matters, not the filesystem of the partition on which the container resides as a file.

To be clear, the container file is treated as an independent drive/partition in itself by truecrypt. It has a filesystem of its own which is chosen at the time when you create a container.

[arumiat]

Hi Varun, sorry I only saw your initial message after posting mine about the FAT32 external HDD transfer..

As requested (using Terminal!)
xxxxxxx@xxxx-W35-37ET:~$ mount
/dev/sdb5 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/sdb1 on /boot type ext4 (rw)
/dev/sdb6 on /home type ext4 (rw)
gvfs-fuse-daemon on /home/xxxxx/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=xxxxx)
truecrypt on /tmp/.truecrypt_aux_mnt1 type fuse.truecrypt (rw,nosuid,nodev,allow_other)
/dev/mapper/truecrypt10 on /media/truecrypt10 type hfsplus (ro)

So looks like you were indeed right about the container being HFS+ (i.e. a MacOSX based file-system)

From what you said in your second response it sounds like I could copy all the files 'inside the Truecrypt container' mounted on my MacOSX over to my FAT32 external HDD. Then to Ubuntu & then create a new container inside Ubuntu using Truecrypt & re-encrypt them?

Thanks for your help, this is the last milestone from being able to sell my Mac!

[cincinnatus13]

^ That'll work just fine.

[varunendra]

From what you said in your second response it sounds like I could copy all the files 'inside the Truecrypt container' mounted on my MacOSX over to my FAT32 external HDD. Then to Ubuntu & then create a new container inside Ubuntu using Truecrypt & re-encrypt them?

That will be an easy (but lengthy) fix, like cincinnatus13 already pointed out.

Also, based on this part of the mount command output -

/dev/mapper/truecrypt10 on /media/truecrypt10 type hfsplus (ro)

.. I think you should be able to mount it with both read/write permissions by just installing "hfsutils" package -

sudo apt-get install hfsutils

From its description -

Tools for reading and writing Macintosh volumes
HFS is the native Macintosh filesystem format.
.
This package contains several command-line utilities for reading and
writing Macintosh HFS-formatted media such as floppy disks, CD-ROMs,
and hard disks.

Whatever suits you better.


EDIT:
If hfsutils alone doesn't help, try additionally installing hfsplus package also -

sudo apt-get install hfsplus

It is specifically meant to add support for hfs+, but doesn't mention explicitly if it can support write access to it.