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Questions tagged [dm-crypt]

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Partition size mismatch using df and lsblk comands

On one of our systems, Additional SSD device mounted is showing size of 5.8 TB, but same partition showing size of only 59 GB using df command- [opc@kms10]$ df -Th /data1 Filesystem Type ...
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12 views

Addressing USB-Stick by UUID as kernel parameter in grub.cfg

I'm using Arch Linux and setting up an USB-Stick as decryption key for my luks-encrypted root partition (boot is unencrypted). I described it already in this question. Now, the key, that's used for ...
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1answer
16 views

Using space before 1st partition of USB-Stick as luks key

I'm using arch linux with an encrypted luks root partition (boot unencrypted), with a passphrase yet. Now I have a keyfile (3072 bytes), that's written to USB-Stick this way: sudo dd if=tempKeyFile....
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8 views

dm_crypt mount on login takes 90 seconds

I'm trying to configure automounting encrypted home on login with user password=encryption password. I'm using archlinux + kde + sddm + crypsetup (dm_crypt). Following archlinux article I did as ...
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1answer
91 views

A separate partition for a user's /home directory?

Is it possible to separate /home/$USER for one particular user into a separate partition in Arch Linux x86_64 with the 4.19.31-1-lts kermel? I want to encrypt one user's /home directory, but I prefer ...
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1answer
178 views

Bad magic number in super-block: dm-crypt device

I have a device that is encrypted using dm-crypt. This is a mini SD card that I use on my laptop. I've had some issues with my laptop freezing recently, and in the journal these messages come up: ...
0
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1answer
186 views

Encrypting a currently used external hard drive such that it can be updated with rsync?

I currently have an unencrypted external hard drive that I use as a backup for my encrypted (with LUKS) main machine. To update my backup, I simply log in to the main machine and rsync to my external ...
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1answer
38 views

Safest way to store TLS private keys without a security module

I am using BeableBone Black devices running Debian which communicate securely with an AWS server over TLS using signed certificates. I need to store my private keys securely on the devices. The best ...
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42 views

How to “cryptsetup open” an encrypted disk with user rights?

I have an encrypted flash drive drive for some private data. It was set up using dm-crypt/cryptsetup. Everything works fine, except that I always have to use root rights to run cryptsetup open /dev/....
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36 views

How to create an encrypted partition and how does Linux then decrypt it [duplicate]

I'm still very much in the learning phase of Linux especially for the use in embedded systems. My intention is to create a separate encrypted partition on an SD card, possibly by using dm-crypt. ...
2
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1answer
100 views

Creating an encrypted partition to store private keys [closed]

I am using a BeagleBone Black board running Debian. My intention is to create a separate encrypted partition to store private keys in the internal emmc. The keys are used for SSL communication. The ...
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1answer
39 views

Find physical block device of root filesystem on an encrypted filesystem?

I'm running Arch Linux (systemd) on several systems. Some have SSD storage, others have nvme storage devices and some use rotational HDD's. Some systems use dm-crypt to encrypt the filesystem. All ...
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2answers
708 views

How to specify cryptdevice by label using systemd boot?

I'm running Arch Linux with systemd boot. In /boot/loader/entries/arch.conf I currently specify the luks crypto device with a line like this: options rw cryptdevice=/dev/sda1:ABC root=/dev/...
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1answer
36 views

The password of previously encrypted volume got changed by the Debian installer

I already did some research on my question (see below), and it's as good as a 'done deal' but I would still like to put forward my problem to this knowledgeable community. Short version of the issue: ...
0
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1answer
92 views

Cryptmount-setup is not working

When I tried to set up encryption using cryptmount-setup, it just returns without any feedback. It did not even created the crypto.fs file. I ran the commands: cryptmount nextcloud_data and cryptmount ...
3
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1answer
66 views

Security of key reuse with dm-crypt in plain mode?

Are there, from a cryptanalysis point of view, security drawbacks when reusing the same key for different volumes in dm-crypt plain mode with cypher aes-xts-plain64? # Example: Encrypt two volumes ...
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2answers
550 views

Can't boot Arch Linux after installation with dm-crypt whole system encryption (BIOS)

So I'm installing a new Arch with the document here for a whole system encryption. The first part I get confused is here which the document wrote: Warning: GRUB does not support LUKS2. Do not use ...
2
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1answer
704 views

veritysetup verify successful but mount fails after upgrade to new kernel

We are using dm-verity for a squashfs root file system. Using kernel 4.8.4 everything was ok, after upgrading to kernel 4.14.14 mount fails, even though the veritysetup verify command validates the ...
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1answer
303 views

change designated name of encrypted lvm root? from sdo to sdn in crypttab?

I installed debian stretch using encrypted lvm from the installer on a usb drive. during installation, with all disks connected, sdo5 is assigned to my boot disk. when running the full system, my ...
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1answer
325 views

How to dm-crypt the data only once by filesystem level RAID?

I'd like to use dm-crypt with btrfs, because of the bitrot protection of this filesystem. What I am worrying about that the RADI1 is on the filesystem level above the dm-crypt, so if I write a file, ...
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1answer
639 views

dm-crypt / cryptsetup which block encryption dimension use

I'm working on dm-crypt utilizing cryptsetup. I'm interested to understand if it's using a fixed block dimension to encrypt files. I explain it better: I created a LUKS envelop, formatted it with ...
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0answers
675 views

cryptsetup, LUKS, dm-crypt benchmark

I'm working on embedded software, where I used the cryptsetup to create an encrypted disk space over a NFS ethernet standard connection... I'm interested to understand the writing speed that this disk ...
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0answers
218 views

Unable to mount decrypted image

I have an encrypted image (ext4) that can be mounted perfectly on my Raspberry Pi but not on my (L)Ubuntu VM. The following commands work perfectly on the Pi: sudo cryptsetup luksOpen stuff.iso img ...
2
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1answer
916 views

Filling SSD with Random Data for Encryption with Dm-Crypt

I need to encrypt an SSD drive and I have opted to use dm-crypt. This is not something I do on a regular basis. So far I have successfully cleared the memory cells of my SSD with the ATA secure erase ...
2
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1answer
544 views

How to remove LUKS encryption after transferring files to an unencrypted disk

My / was originally on an encrypted volume and was transferred to an unencrypted volume by recursively copying every directory, and then grub was reinstalled: sudo -s cp -ax /mnt/encrypted /mnt/...
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1answer
2k views

LUKS passphrase doesn't work

One day, when I turned on the computer, my passphrase for home part /dev/sda7 doesn't worked (I am 147% absolutely sure, that I was writing right pass)! After three times of tries, I have rebooted ...
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0answers
609 views

Open a LUKS volume as a non-root user?

I'm using cryptsetup to create a LUKS file-based device to stash information in: # create a file as a container dd if=/dev/zero of=zulu.bin bs=1024 count=102400 # create a key dd if=/dev/urandom bs=1 ...
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0answers
241 views

Is it possible to decrypt a single isolated dm-crypt sector (perhaps using OpenSSL)?

Given full knowledge of the parameters required to open a dm-crypt volume, is it possible to decrypt a single sector taken from such a volume ? Assume that the original volume is not available but ...
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1answer
2k views

LUKS with USB key authentication, how secure is it?

I am thinking of creating a LUKS encryption by using a USB key instead of a passphrase to unlock my hard drive. However some people told me that using a USB key for authentication is less secure than ...
2
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1answer
542 views

Auto-mount encrypted volume on boot with key in crypttab

I have a LUKS-formatted volume and crypttab that contains the following: cryptdata UUID=3e26bc03-... /etc/cryptdata.key When the system boots, systemd asks me the password for this volume ...
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0answers
380 views

Documentation on Device Mapper ioctls?

In the Red Hat documentation on Device Mapper, it reads: "the application interface to the Device Mapper is the ioctl system call." So far, I understand that the ioctls are sent to /dev/mapper/...
2
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1answer
410 views

How to make device mappings stay after reboot?

I notice that if a device mapping is created with the low-level dmsetup or through ioctls, the device mapping will no longer be there after reboot. Is this normal? I am using a USB to test out ...
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1answer
106 views

Copy bootloader/boot partition to another disk (cdm-crypt)

I installed Debian jesse on an USB stick. I have like usual in these cases 4 partitions. Boot, root, swap, home. Last 3 of course encrypted. But during installation, I don't know why, Debian didn't ...
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2answers
51 views

Can dm-crypt be configured to ask for key on every read/write?

My understanding is that dm-crypt serves to abstract the actual block device so that the read/decrypt and write/encrypt happen automatically. However, assuming a device mapping with target: crypt is ...
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0answers
213 views

Debian Jessie - Can't boot after install dm crypt + luks - grub error

So after following this tutorial. Grub fails to load this new Debian installation. I followed that whole tutorial with 1 exception: I setup the 3 partitions all with 3 different passwords. everything ...
2
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1answer
714 views

Unlock Android encrypted DISK IMAGE FILE of SD card on desktop Linux

I am able to successfully unlock a corrupted Android encrypted SD card on desktop Linux using instructions from the Internet. # dmsetup create crypt5 --table "0 `blockdev --getsize /dev/mmcblk0p2` ...
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1answer
2k views

fstrim doesn't seem to trim a partition that uses lvm and dm-crypt

I try to setup Fedora 25 with dm-crypt and LVM, but struggle to make TRIM work. $ sudo fstrim -av /boot: 28.6 MiB (30003200 ...
3
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1answer
2k views

LUKS password not being requested by dmcrypt / encrypt hook at boot

At boot I see: :: running hook [encrypt] A password is required to access the volume: Command requires device and mapped name as arguments Command requires device and mapped name as arguments ...
3
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1answer
2k views

LUKS discard/TRIM: conflicting kernel command line options

I'm confused between the various ways that LUKS/dmcrypt/cryptsetup discard /TRIM operations can be enabled via the Linux kernel command line. The dracut manpage: rd.luks.allow-discards Allow ...
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0answers
841 views

Is Easy-to-use Multi-factor Full Disk Encryption Available?

I had a setup where my removable device contained a single partition with encrypted data and nothing else on it to distinguish it from random data. On a physically separate device, I had a pair of ...
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0answers
322 views

Is multiple ecryptfs encryption possible?

Is multiple ecryptfs encryption possible? How to encrypt a folder called level2 with ecryptfs that is inside a ecryptfs mounted folder called level1? level1 and level2 folder are organized as # ...
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0answers
270 views

dm-crypt / luks partition disappeared

I have a big problem with a partition that is encrypted with luks/dm-crypt. I recognized that some files were not readable any more. I rebooted and the partition was not mountable. As far as I ...
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0answers
580 views

Debian fails to prompt for encrypted disk password on boot

I am using Debian Scratch with encrypted root partition. The last kernel version where it worked was 4.6.0. For kernels 4.7.0 and 4.8.0 it prints on the boot repeatedly and forever following messages: ...
5
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1answer
2k views

What does `cryptsetup resize` do if LUKS doesn't store partition size?

The LUKS / dm-crypt / cryptsetup FAQ page says: 2.15 Can I resize a dm-crypt or LUKS partition? Yes, you can, as neither dm-crypt nor LUKS stores partition size. I'm befuzzled: What is "...
3
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1answer
405 views

Does dm-crypt utilize multiple cores? (Interested in multi-core Pi clones)

I'm considering replacing single-core Raspberry Pi with an encrypted disk with multi-core Banana Pi M3. Encryption/decryption performance is currently the bottleneck, so I'd like to know if encryption ...
3
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1answer
53 views

How to gradually delete a file in parallel to encryption?

I need to encrypt a huge file but don't have sufficient storage on my hard-drive to store the file and its encrypted version at the same time. It appears possible to gradually delete the file ...
2
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1answer
964 views

Why is my keyfile in /etc/crypttab not recognized?

I setup dm-crypt for a non-root partition on an Arch Linux installation and referenced a keyfile in /etc/crypttab (permissions -rw-------). However, during startup, I still get prompted for the ...
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1answer
127 views

Grub 2 fails to open luks container with strong password

I've encrypted my /boot partition with dm-crypt in a luks container. I've added a strong password to the slot #0 of the luks container. Now I can open the container from a live CD successfully but ...
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0answers
2k views

btrfs error unknown - root fs will not mount

I am running Arch Linux on a system with full disk encryption and the storage is a Samsung 950 Pro NVMe drive (512 GB). The computer is a couple months old. No bad behavior until now. (I'm only using ...
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1answer
237 views

Mounted drive disappears and is no longer a valid LUKS device

A few days ago, I formatted and encrypted (LUKS+Ext4) a solid state drive the lazy way (using gnome-disks). The disk was mounted and I moved some data to the disk from another drive that I was going ...