Questions tagged [dm-crypt]

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Load dm-crypt on Ubuntu Server 18.04 LTS in Windows Subsystem for Linux 1 or 2

I'm using Windows Subsystem for Linux (WSL1) on my Windows 10 system and tried to delete all data from a USB device and overwrite it with pseudorandom numbers following this tutorial (found it only in ...
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1answer
90 views

disk partition encryption: /etc/crypttab file ignored

I'm fairly new to luks and cryptsetup tool and trying to use them on a Beaglebone to encrypt a partition. I'm able successfully encrypt a partition and then access it and mount the mapped device ...
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1answer
525 views

What is the default encryption key-size for dm-crypt / cryptsetup in LUKS mode?

I'm using cryptsetup 2.1.0, for which the default encryption options are (as reported by cryptsetup --help): Default compiled-in device cipher parameters: LUKS: aes-xts-plain64, Key: 256 bits, ...
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2answers
167 views

Understanding plain dm-crypt, cryptsetup, mapping; securely wiping data using plain dm-crypt

I stumbled upon this while trying to wipe my whole disk using plain dm-crypt as suggested, e.g., here (arch linux wiki): # cryptsetup open --type plain -d /dev/urandom /dev/sda to_be_wiped # dd if=/...
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1answer
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Crypted drive, rsync and no space on half used drive

I have very strange problem that I don't know how to debug further. Drive is WD 2TB. I use it only for backup of my cloud and server data (lot of small files). I'm using linux and dm-crypt.. whole ...
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1answer
345 views

LUKS detached header on RHEL 6

Is there any version of cryptsetup which supports LUKS detached header on RHEL-6 ? cryptsetup provides detached header support on RHEL-7 (cryptsetup-1.4 onwards) but not on RHEL-6. I tried building ...
2
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1answer
824 views

dmcrypt : What happens when userspace crypto wrapper not present?

I am trying to set up an encrypted volume to store files securely. This is done on a NextThingCo pocketchip, but the OS is based on debian so I guessed I would give it a try here first, as my question ...
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2answers
2k views

LUKS - change keyFile using cryptsetup

cryptsetup utility provides the option to change existing passphrase using luksChangeKey option. This requires the older key-file and other parameters as suggested on the man page. luksChangeKey &...
1
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1answer
729 views

LUKS - Detached header - where is encryption key stored?

I encrypted a disk using LUKS with detached header. The header was present on a removable disk. Once the mapped device (under /dev/mapper) was created, I removed the disk containing header. I was ...
2
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1answer
1k views

How to configure grub.cfg to decrypt root partition?

I'm using common "pattern" well known as LVM on LUKS. I have /dev/sda1 which is used for /boot and /dev/sda2 which is dm-crypted partition (default aes-sha512-xts). There are two lvm partitions: one ...
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1answer
476 views

Passing keyfile to create LUKS header

The dm-crypt LUKS utility 'cryptsetup' allows us to specify the key-file in place of passphrase. Looking at the code for cryptsetup I understand that if key-file is specified, the passphrase is not ...
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0answers
513 views

dm-crypt/LUKS, won't mount encrypted drive. Requested offset is beyond real size of device

I screwed up my partition table the other day but had recovered it with TestDisk. After re-writing the partition table, I'm able to boot up into GRUB and subsequently the interface for entering my ...
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0answers
567 views

dm-crypt+LUKS performance and influence on RAM usage

I'm using dm-crypt + LUKS to encrypt 3 partitions of my disc. Recently I started wondering how does it influence my system.. I know that due to the decryption the boot time is longer, but I would ...
10
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1answer
17k views

LUKS on Ubuntu 16.04 : unknown filesystem type 'crypto_LUKS'

I'm using (L)Ubuntu 16.04. I would like to backup my files on an external hard drive (sdd) with LUKS. There was no partition (sdd1, etc.) before the cryptsetup command. #sudo cryptsetup -v --cipher ...
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1answer
2k views

Arch - GRUB with dm-crypt LUKS on LVM

The last time I had to install Arch was a year or so ago. Grub always gives me the most trouble but I prefer it over syslinux. HOW CAN I GET GRUB TO RECOGNIZE MY ENCRYPTED VOLUME? I get the GRUB ...
2
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1answer
463 views

Can I make a encrypted image by using openssl encrypt tools instead of dmsetup?

Generally, I can create a encrypted ext4 image by do this: fallocate -l 6553600 encrypt.img losetup -f encrypt.img dmsetup create encrypt_disk --table "0 12800 crypt aes 32BYTEKEY 0 /dev/loop0 0" ...
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1answer
2k views

dm-crypt with LUKS - /etc/crypttab using either keyfile or passphrase

I have my home partition encrypted using dm-crypt and LUKS header. I have two slots in its header: first one is a passphrase and second is keyfile. I have keyfile on external drive which I use only as ...
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2answers
2k views

can we do the full disk encryption of a already installed Linux machine?

I need some information regarding any possibility to do full disk encryption for a already installed Linux system(e.g centOS or Ubuntu). Is there any default mechanism for FDE present in Linux like "...
1
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2answers
2k views

How to recreate encrypted dm-crypt/LUKS partition with predefined UUID on Linux?

I have / and swap area of Ubuntu 14.04 LTS (and Linux Mint 17.1 LTS) encrypted in dm-crypt/LUKS. / and swap area reside in /dev/mapper/UUID_1 and /dev/mapper/UUID_2. Is it possible to recreate the /...
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1answer
142 views

Set parameters for Linux Full Disk Encryption?

How do I change the parameters (algorithm, hash, key-lengh, block-size, IVs, mode-of-operation, key-derivation function etc.) for the encryption being used by Linux built in Full Disk Encryption (...
2
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1answer
212 views

Setting up remote git repo that is on an encrypted drive?

I would like to set a remote git repo that I will be pushing to regulary, which is easy to do. But I want to set up this remote repo to be on a LUKS (Linux Unified Key Setup) formatted drive (via ...
3
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1answer
4k views

dm-crypt+luks: Can I have a separate header without storing it on the luks encrypted device?

I would like to encrypt my external hard drive with dm-crypt+luks, but I am not satisfied with all the information, that the LUKS header is providing in plaintext. So I would like to keep the LUKS ...
3
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0answers
472 views

Is there a tool like dm-crypt/luks using RSA encryption?

Is there a library/tool available for linux, similar to dm-crypt/LUKS using RSA encryption instead of symmetric ciphers? I want the "public side" to only be able to create these volumes, and the ...
13
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3answers
9k views

How do I determine what ciphers & cipher modes I can use in dm-crypt/LUKS?

I'm using an Ubuntu-based system, and I'm having difficulty determining what ciphers and cipher modes are available to me. The cryptsetup man page says: "See /proc/crypto for a list of available ...
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2answers
424 views

Is it possible to add a key to an open luks volume whithout providing a current key?

As the title states, I need to know if there is a method to add a key that doesn't require the user to retype the password / provide a keyfile for an already open luks volume. I'd actually need to ...