Fedora Security :: Remove Boot Mount Of Dm-crypt LUKS Md1?
Dec 22, 2009
When I upgraded from FC11 to FC12 of the encrypted raid partitions started to request password on boot (in FC11 not having references to encrypted md1 in fstab and crypttab, was enough for FC11 not to ask for passwords on boot) despite the fact that I removed /etc/crypttab and there is nothing in /etc/fstab relating to encrypted md1 (raid array). I want my machine to boot w/o asking me passwords for encrypted devices, and I will open and mount them myself manually after boot.
It seems I've run into a bit of a problem. I recently upgraded to the latest kernel 2.6.32-24-generic (x86) but when I reboot into the new kernel and type in my password the system hangs, same when using a keyfile on the root file system.to give an outline of how the disks are setup.3 hard drives
I'm trying to have a LUKS encrypted partition mounted at startup and to have GDM ask for my key so it will decrypt. Now I followed [URL] to the letter. Except for now, I have it just mounted into /mnt/cryptohome so I'm not messing with my system. My problem is the one everyone mentions in the comments, ubuntu isn't asking for the LUKS key in the X display, it's asking in the first terminal (Ctrl-Alt-F1). This will not do. I need it to ask to mount my drive before I'm even asked to login, so eventually I can encrypt my /home.
I'm simply interested in a more basic discussion of why one would choose one of these methods over the other. What do they offer that the other does not? I'll start with what I know:
- dm-crypt/LUKS --- included in a lot of install images already; in other words, perhaps easier to implement on a fresh install - TrueCrypt --- multiple encryption algorithms possible
For me... I have no need for Windows compatibility, though I do use OS X on a dual booting MacBook. I believe TrueCrypt woks with OS X, so that could be a bonus, though I can simply encrypt my home folder on OS X with it's own FireVault and be fine.My setup (after wiping and starting over) will probably be like so:
- /boot on it's own primary partition - / on it's own primary partition with logical partitions within --- /usr, /var, /etc, /opt, and the like on a logical partition --- /home on a logical partition
/home will surely be encrypted and I'm leaning toward encrypting the rest as well, though perhaps it's not necessary. I'm open to input there as well -- is there anything the leaks from normal application use into /var or /tmp that would make one lean toward just encrypting the whole thing?
I opened up TrueCrypt just to look at it and since I can't encrypt a whole partition without losing data... I pretty much have to encrypt from what? A live CD? This could be a drawback -- I think since TrueCrypt isn't coming on install disks, I'd have to go with an unencrypted (or dm-crypt/LUKS) root partition and then use TrueCrypt to make a container (or partition) for /home only. I can't think of another way to do this since I can't encrypt the whole disk as one entity with my dual booting situation...
Since i'm on-the-road a lot encryption is crucial, with windows i've always used TrueCrypt and DiskCryptor, this is very easy to setup and allows me to create usb/cd devices that i can boot off and contain a keyfile, on boot it also requires a passphrase. Currently all i need to do is boot from harddisk and enter my passphrase. I would like to be able to boot from external device (in this case USB) that contains the bootloader and an integrated keyfile, also it should requist the passphrase. I found a guide on how to achieve two-factor authentication with dm-crypt on feisty but it's quite an old guide and is realy realy complicated for a newbie
I need a FREE solution that can image an entire Luks system encrypted volume and the rest of the used HDD, the MBR and /boot partition. Note: MBR and /boot are not encrypted. Note 2: I want to be able to restore entire drive from image with only a couple of steps. Note 3: Destination HDD space is a factor. Image file must be compressed and the image file must be around 40 to 50 GB or less. The smaller the image the better.
I have used clonezilla live cd before but not for encrypted volumes. I know you can install it in Linux. But, I don't know how to configure it after installation. I would be very happy if someone could tell me how to configure clonezilla in Fedora. How to guides are also welcome. I have one more question. If I image the encrypted volumes and all the stuff I mentioned above while logged in to Fedora, and I restore the drive from the image, will the recovered drive still be encrypted?
I'm having a problem auto-mounting a new luks partition. I have crypttab and fstab entries. I already have my primary encrypted partition (root) mounting at boot (from the install), but after creating this one manually, it does not open on boot. It auto-mounts when I run the following command manually after boot: sudo luksOpen /dev/disk/by-uuid/<uuid> mycrypt
I know how to mount it manually. I've seen a howto on how to mount it automatically by loging in with the user, you type your username and password and it mounts your encrypted partition. But that's not what I want. My idea is to call cryptsetup and mount on boot, AND ask me for passphrase like when its loading the system, then if I don't type the right password it shouldn't mount /home, even though i type the correct USER password later when the system is loaded(and then I'd have an empty /home since my home partition wasn't mounted due to wrong passphrase).
This is what I tried: I added the commands to rc.local and I don't even feel like it was executed, no passphrase was asked. As a test if commands there were being executed, I tried simple commands lile mkdir /test and it worked. So commands there are executed, yet, no passphrase was asked to me, I looked on dmesg for crypt and found nothing, I pressed alt+ctrl+F1 desiring to find a passprhase-ask and again, nothing.
Has anyone tried encrypting the boot partition to prevent the kernel from being modified. Iv tried following this but I'm running into issues when building. [URL] Im using the source from bzr checkout [URL] Last time I tried I screwed grub and it wouldnt boot.
1.) I am wondering how to enable the lock to an encrypted partition which has been unlocked, using luks? On boot, I am been asked automatically for the pass phrase to unlock my partitions. After doing a back up, I want lock the encrypted partition again, but I don't know the command?! I umounted the partition but after mounting it again, I was not asked for the pass phrase but had access to my data.
2.) How secure is the default fedora version of luks? Is truecrypt better?
I'm planning a fresh F13 install, with separate partitions for /boot, /home, /tmp, /, and swap. All but /boot will be logical volumes, and I'd like to encrypt all but boot. If I encrypt the underlying partitions, is there any reason to also encrypt the logical volumes themselves?
my system will be: HP dv6-3040us Pavillion laptop AMD Phenon II 4GB DDR3
I run fedora 13 on my laptop (dual boot with Windows 7) and I just created a new partion to hold sensible data, encrypted with LUKS. I followed this tutorial for creating it.Now, everything went well and the new partition works well. But I needed something a little different from what the tutorial suggested, because I don't want the partition to be mounted on the system each time it boots, but I would (unlock and) mount it manually when I need it.
To do so I just didn't follow the Tutorial steps from 7 to 13, thinking that without the changes to crypttab and fstab the partition wouldn't be even touched by the start up process. And that's partially true: the partition isn't mapped nor mounted in the system when I boot, but the problem is that it however keeps asking for the passphrase to unlock it even if it doesn't get mounted or mapped.It just asks for it before the system loads all it's parts (udev, filesystems, etc) and I can't understand why, what it uses it for if it doesn't unlock it.So my question is: why does it ask for the passphrase to unlock luks if I haven't set crypttab and fstab to mount the partition on start up?
I'm not a mathematician or cryptographer, only an end user of the technology trying to determine the "best" or safest future proof option to go with for long term archival while also maintaining reasonable performance with dual opteron ~2GHz or similar setup. I've noticed aes-cbc-essiv seems to be the default choice in various installers for reasons of backwards compatibility while others are moving towards XTS since the standardization.
and I'm dumped into recovery mode. However, if I remove these mounts from /etc/fstab via comments, I can wait for the system to boot (which it does very quickly) then mount the mapper devices myself. So what is going on? Has something changed wrt logical volumes, or is this just systemd? I can live with manual mounting, but any advice on resolving the automatic mounting situation would be great.
The reason I want to delete the LUKS password is simply that I do not want to have to put it in for each server just to get the system to boot. I am planning to cluster the servers as well and like I said before I don't want to put the password in each time since they won't be running all the time.
I just bought a new laptop which will be running SSD (Corsair 120GB) as the boot drive and would like to migrate my OS to the new system. One of my requirements is full-disk encryption. I work with proprietary client data and need to encrypt the new drive, its swap partition, everything except for /boot. I've read instructions for doing this from the alternate install CD, but my OS is disturbingly customized (started out as 10.04) and it would take months to rebuild everything. I keep remastersys (-dist) ISOs to ensure I don't have to go through that process, but the ubiquity installer does not appear to have the option of doing disk-level crypt during the installation process. I can boot the ISO into CLI, but don't know how to run the alternate installer from there.
If I leave the computer running for a few minutes without doing anything on it, this screen appears demanding that I enter my password, otherwise I can't get back to Fedora. I understand the necessity for this security feature in a work environment, but I'm just a home user and this security screen is just a nagging problem I don't know how to get rid of.
sda is what I currently run to write this text, sdb is my former harddrive, connected via USB.
I want to access the root partition on sdb.
The problem is:
Code: Select allcryptsetup luksOpen /dev/sdb5 oldhd Enter passphrase for /dev/sdb5: root@x200s:/home/b# ls /dev/mapper/ control oldhd sda5_crypt x200s--vg-root x200s--vg-swap_1 root@x200s:/home/b# mount /dev/mapper/oldhd /mnt/ [b]mount: unknown filesystem type 'LVM2_member'[/b]
Before all this, both sda and sdb where in the same volume group. I renamed the volume group of sdb to "oldDisk" using
Code: Select allvgrename <UUID> oldDisk
How I can access the data on the root filesystem of my sdb..
I just created a LUKS filesystem following these instructions. Everything seemed okay at first. It mounted with no problem and I moved some files there. I then unmounted it and remounted it to see if I would need to use a special command. It mounted right away and even allowed access to normal users. So, I rebooted to see if anything would change. Before I go on I should say that my partitioning scheme is weird. Not knowing any better I 'upgraded' to 11.04 when my update manager told me a new version was out. This didn't go well and I had to do a fresh install to put 10.10 back on my machine. After this the way it partitions the drive has been weird. What I had was /dev/sda1 which has my installation on it including /home. But, where it gets weird is /dev/sda2 would not manually mount. Looking at the disk in gparted it showed /dev/sda2 THEN under that, as if they were sub partitions or something, I had sda6 and sda7. I had been using 6 and 7 for various things and they mounted fine, so I decided to encrypt 7. After reboot I only have sda1. Everything else shows up as unallocated and ever way I try to mount I get device does not exist.
I only did the procedure for sda7 but 6 has been affected as well. There is no longer a sda2 the way there was before. This always bothered me anyway since I wanted sda2 for my /home but it wanted to call it sda6 and put it under sda2 like I said, I could never fix that, now this.
I am trying to decide whether or not to use LUKS with LVM install for NAS Box, mysql, postfix, ddns, bind, NFS, sshd, Appletalk, maybe samba. I have decided to give LVMs a try but not sure how LUKS will affect access to services. LAN includes Standalone headless web server(not on LVM, no LUKS). Aren't permissions,iptables and firewalls sufficient? Not sure how services are supose to interract if everything is encrypted especially root?
So far what I have read recommends vgOS /, swap, /var, /tmp encription and vgdata /home encryption but no one tells how they did it. The 2 servers I'm working on only have small /home for admin stuff and considering making NAS headless, except i read somewhere that some gui would make it easier to manage mysql which brings me to the question if I don't install X on NAS can I ssh in with my desktop using its gui? I am experimenting with minimal server tagfiles. LUKS and LVMs are new to me. Decided to use LVMs to seperate OS from data, different data types and resizing flexibility. I have read some material on LUKS just wonder if its more complicated than my needs require. Certainly i don't want to leave myself open to someone just distroying my setup for kicks.
When 10.04 is released I'll encrypt my /home partition using luks. I've read that xts is good for hard drive encryption and aes is good for cipher encryption. I'm looking for something that is fairly secure without sacrificing a lot of speed.
I have a LVM logical volume, that contains a LUKS encrypted volume, on which is an ext4 filesystem. I shrank the partition to the minimum size. Next step is to luksClose the device, and then to resize the LVM logical volume. I suspect that LUKS has overhead. So if the ext4 filesystem was resized from, say 1TB to 500G, I have the idea that resizing the LVM LV to 500G does not take LUKS overhead into account and this might corrupt data on the end of the FS. So, what's the smart move to take? How do I calculate the safe minimum LV size? Or should I just give the 500G disk a few gigabytes extra to be sure?
I'm just wondering - what is the best way to set up your encrypted volumes with dm_crypt and LUKS?
My understanding was that aes-lrw ws better than aes-cbc - and then I stumble upon [url] which says that LRW has some problems, and XTS is better? I dont know enough about encryption theory to be able to say anything, so i'm hoping some folks more enlightened will be able to say something here.
I was previously using aes-lrw-benbi to set up a volume. If xts is truly better - should i be using '-c aes-xts-benbi' then?
I'd like to know if there's a simple way to create a LUKS encryption drive with different passwords? A real one that leads to one set of data, and another that leads to a whole different set of data. Is this even possible with LUKS?
Recently, I started protecting all user-accessible filesystems on my Sidux desktop machine with LUKS. Before that, I would regularly erase traces of deleted data, and I wonder if this is still necessary.
It would be most valuable to me to be pointed towards a good introductory article on the underlying mechanics of LUKS and cryptsetup, as there are a few more minor questions to be answered. Unfortunately, I lack the necessary mathematic and cryptographic background to understand scientific papers.