Help:"Protecting Data w/ Encrypted Linux Partitions"

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03-02-2010
nujinini

Help:"Protecting Data w/ Encrypted Linux Partitions"

Hi!

I was trying to follow the tutorial on "Protecting Data with Encrypted Linux Partitions" by Kashyap.

After I moved all my data temporarily and have started, I encountered this...

Code:

[jun@localhost ~]$ su - Password: [root@localhost ~]# cryptsetup --verbose --verify-passphrase -c aes-cbc-plain luksFormat /dev/sda8 WARNING! ======== This will overwrite data on /dev/sda8 irrevocably. Are you sure? (Type uppercase yes): YES Command failed: Can not access device

So I thought it was a problem in having the /dev/sda8 partition mounted so I executed this. Still got the same error. Can somebody please teach me what am I suppose to do please? Thanks!

Code:

[root@localhost ~]# mount /dev/sda8 /media/sda8 [root@localhost ~]# cryptsetup --verbose --verify-passphrase -c aes-cbc-plain luksFormat /dev/sda8 WARNING! ======== This will overwrite data on /dev/sda8 irrevocably. Are you sure? (Type uppercase yes): YES Command failed: Can not access device [root@localhost ~]#
03-03-2010
devils casper

Mount /dev/sda8 and execute df -h command. Does it list /dev/sda8 in the output?
You are using Ubuntu. Right?
03-03-2010
nujinini

Quote:

Originally Posted by devils casper

Mount /dev/sda8 and execute df -h command. Does it list /dev/sda8 in the output?
You are using Ubuntu. Right?

Hi!

Code:

[jun@localhost ~]$ df -h Filesystem Size Used Avail Use% Mounted on /dev/sda5 11G 9.1G 1.1G 90% / tmpfs 1.5G 256K 1.5G 1% /dev/shm /dev/sda7 34G 28G 5.1G 85% /media/Mint 7 /dev/sda3 106G 81G 26G 77% /media/Storage Bin (A) /dev/sda6 11G 3.5G 6.1G 37% /media/Ubuntu 9.10 /dev/sda1 15G 14G 940M 94% /media/XP Windows :( /dev/sda8 51G 180M 48G 1% /media/Storage Bin (B)_ [jun@localhost ~]$

I was on my Fedora 10 when I tried to follow Kashyap's tutorial. I can do it in my Ubuntu 9.10 if it would make a difference. Or MInt 7.

The above output is from my Fedora terminal which automatically mounts all partitions.
03-03-2010
devils casper

It should work in all distros.
Unmount partition using umount command and execute cryptsetup command again.

Make sure to gain root privileges through su - instead of su.

Code:

su - umount /dev/sda8 cryptsetup --verbose --verify-passphrase -c aes-cbc-plain luksFormat /dev/sda8
03-03-2010
nujinini

Bingo!

Code:

[jun@localhost ~]$ su - Password: [root@localhost ~]# umount /dev/sda8 [root@localhost ~]# cryptsetup --verbose --verify-passphrase -c aes-cbc-plain luksFormat /dev/sda8 WARNING! ======== This will overwrite data on /dev/sda8 irrevocably. Are you sure? (Type uppercase yes): YES Enter LUKS passphrase: Verify passphrase: Command successful. [root@localhost ~]#

Tutorial Output says.

Code:

# cryptsetup luksOpen /dev/sda2 sda2 Enter LUKS passphrase: key slot 0 unlocked. Command successful.

My output is different though:

Code:

[jun@localhost ~]$ su - Password: [root@localhost ~]# # cryptsetup luksOpen /dev/sda8 sda8 [root@localhost ~]#

I wonder why :confused:

Now to continue....
03-03-2010
nujinini

I think I'm getting warmer... :)

Code:

[jun@localhost ~]$ su - Password: [root@localhost ~]# cryptsetup luksOpen /dev/sda8 /sda8 Enter LUKS passphrase for /dev/sda8: key slot 0 unlocked. Command failed: dm_task_set_name: Device /sda8 not found [root@localhost ~]#

Got it!

Code:

[jun@localhost ~]$ su - Password: [root@localhost ~]# cryptsetup luksOpen /dev/sda8 sda8 Enter LUKS passphrase for /dev/sda8: key slot 0 unlocked. Command successful. [root@localhost ~]#

Code:

[jun@localhost ~]$ ls -l /dev/mapper total 0 crw-rw---- 1 root root 10, 63 2010-03-04 06:35 control brw-rw---- 1 root disk 253, 0 2010-03-03 23:14 sda8 [root@localhost ~]# mkfs.ext3 /dev/mapper/sda8 mke2fs 1.41.4 (27-Jan-2009) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 3366912 inodes, 13446268 blocks 672313 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=0 411 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 21 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@localhost ~]# [jun@localhost ~]$ mkdir /home/jun/crypted [jun@localhost ~]$ su - Password: [root@localhost ~]# mount /dev/mapper/sda1 /home/jun/crypted mount: you must specify the filesystem type [root@localhost ~]# df -H Filesystem Size Used Avail Use% Mounted on /dev/sda5 12G 9.8G 1.2G 90% / tmpfs 1.6G 78k 1.6G 1% /dev/shm /dev/sda7 37G 30G 5.6G 84% /media/Mint 7 /dev/sda1 16G 14G 2.4G 86% /media/XP Windows :( /dev/sda6 11G 3.7G 6.6G 37% /media/Ubuntu 9.10 /dev/sda3 113G 86G 28G 77% /media/Storage Bin (A) [root@localhost ~]# [jun@localhost ~]$ su - Password: [root@localhost ~]# mount /dev/mapper/sda8 /home/jun/crypted [root@localhost ~]# df -H Filesystem Size Used Avail Use% Mounted on /dev/sda5 12G 9.8G 1.2G 90% / tmpfs 1.6G 78k 1.6G 1% /dev/shm /dev/sda7 37G 30G 5.6G 84% /media/Mint 7 /dev/sda1 16G 14G 2.4G 86% /media/XP Windows :( /dev/sda6 11G 3.7G 6.6G 37% /media/Ubuntu 9.10 /dev/sda3 113G 86G 28G 77% /media/Storage Bin (A) /dev/mapper/sda8 55G 189M 52G 1% /home/jun/crypted [root@localhost ~]# cd /home/jun/crypted [root@localhost crypted]# nano test [root@localhost crypted]# ls lost+found [root@localhost crypted]# [jun@localhost ~]$ su - Password: [root@localhost ~]# mount /home/jun/crypted /sda8 mount: you must specify the filesystem type [root@localhost ~]# mount /dev/mapper/sda8 /home/jun/crypted mount: /dev/mapper/sda8 already mounted or /home/jun/crypted busy mount: according to mtab, /dev/mapper/sda8 is already mounted on /home/jun/crypted [root@localhost ~]# mount /home/jun/crypted sda8 mount: you must specify the filesystem type [root@localhost ~]# mount /home/jun/crypted /media/sda8 mount: you must specify the filesystem type [root@localhost ~]# mount /dev/mapper/sda8 /home/jun/crypted mount: /dev/mapper/sda8 already mounted or /home/jun/crypted busy mount: according to mtab, /dev/mapper/sda8 is already mounted on /home/jun/crypted [root@localhost ~]#

Can you please help me on the last portion? Thanks!
03-03-2010
zombykillah

I've never done this myself ... but it doesn't seem logical to me to mount the device.

As far as I know the en/decryption will be before the file-system ...
So you need to check that the device isn't mounted.

Just that way an encryption without any file-system dependencies gets possible ...
But it may cost redundancy with the data integrity ...

So both ways could be logical ...

So I checked in the internet:
cryptsetup - LinuxWiki.org - Linux Wiki und Freie Software
Is in german ... but in the first part it's written that the file system shall be made on the new device created by cryptsetup.
The device can be found in:
/dev/mapper/$NAME

so try following:

Code:

su umount /dev/sda8 cryptsetup luksOpen /dev/sda8 sda8 ...

just saw you allready got that one ...

so you are missing a filesystem.
mkfs -t xfs /dev/mapper/sda1
for example
03-03-2010
zombykillah

Just reeded your description again ...
Damn you already have one ... I need to concentrate more ... may I shall dink some beer too increase it ...

The only thing I can think about is that the file system is only mounted ro.
However there should be a error msg when you try to exit nano or try to "touch test"

You can only mount a device that isn't already mounted ... so you need to write a unmount /home/jun/crypted
03-04-2010
nujinini

Quote:

Originally Posted by zombykillah

I need to concentrate more ... may I shall dink some beer too increase it ...

hahaha!

Thanks. Please help me analyse more :)
03-04-2010
zombykillah

Hi ...
I've just tried to do it on my server ... till folowing line showed up:

Code:

slavi:~# cryptsetup --cipher aes --key-file key.txt create sda6 /dev/sda6 Aufruf fehlgeschlagen: Incompatible libdevmapper 1.02.27 (2008-06-25)(compat) and kernel driver

Well I'll try it on the other machine ...

Genial ...

Code:

SERVI:~# cryptsetup --cipher aes --key-file key.txt create crf1 /dev/sdf2 Aufruf fehlgeschlagen: Incompatible libdevmapper 1.02.27 (2008-06-25)(compat) and kernel driver

Well it seems I don't even come to the point you need help ...

With the following command you can check all mounted devices with their options:

Code:

cat /etc/mtab

Example:

Code:

SERVI:~# cat /etc/mtab /dev/sda1 / ext3 rw,errors=remount-ro 0 0 tmpfs /lib/init/rw tmpfs rw,nosuid,mode=0755 0 0 proc /proc proc rw,noexec,nosuid,nodev 0 0 sysfs /sys sysfs rw,noexec,nosuid,nodev 0 0 procbususb /proc/bus/usb usbfs rw 0 0 udev /dev tmpfs rw,mode=0755 0 0 tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0 devpts /dev/pts devpts rw,noexec,nosuid,gid=5,mode=620 0 0 /dev/sdf1 /media/sdf1 ext2 rw 0 0

You can see all options that were used during mount as rw read-write or ro read-only
Hope that helps you ...

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