Note: This page is horribly out of
date.
You can find the current pages for the dm-crypt
project (the Linux kernel part) here:
https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt
and the project page for the command line tool
cryptsetup (with Linux Unified Key
Setup - LUKS) here: https://gitlab.com/cryptsetup/cryptsetup.
Old page:
Device-mapper is a new infrastructure in the Linux 2.6 kernel that provides
a generic way to create virtual layers of block devices that can do different
things on top of real block devices like striping, concatenation, mirroring,
snapshotting, etc... The device-mapper is used by the
LVM2 and
EVMS 2.x tools.
dm-crypt is such a device-mapper target that provides transparent encryption of
block devices using the new Linux 2.6 cryptoapi. The user can basically specify
one of the symmetric ciphers, a key (of any allowed size), an iv generation mode
and then the user can create a new block device in /dev. Writes to this device
will be encrypted and reads decrypted. You can mount your filesystem on it as usual.
But without the key you can't access your data.
It does basically the same as cryptoloop only that it's a much cleaner code and
better suits the need of a block device and has a more flexible configuration
interface. The on-disk format is also compatible. In the future you will be able
to specify other iv generation modes for enhanced security (you'll have to
reencrypt your filesystem though).
I've set up a Wiki.
There's a mailing list at .
If you want to subscribe, use the mailman
web interface or its
archive.
Gmane provides a NNTP interface and also a
web archive
for this mailing list.
There is support for dm-crypt in the latest official kernel
2.6.4
which you can find on kernel.org.
Please use the mirrors for downloads.
There is a HIGHMEM cryptoapi bug in kernels before 2.6.4-rc2, please
upgrade if you were using such a kernel.
The latest version of the native userspace setup tool is cryptsetup 0.1.
Clemens Fruhwirth is maintaining an
enhanced
version of cryptsetup with the LUKS extension that allows you to have an
on-disk block of metadata which is superior to the current mechanism and was
my long term plan anyway but I didn't find the time to implement that yet...
It is impossible to discuss the Indian family lifestyle without mentioning festivals. The calendar is dotted with celebrations—Diwali, Eid, Eid-ul-Fitr, Christmas, Navratri, Pongal, and Durga Puja, to name just a few.
Evening stories often happen around the "tea table." This is when the family gathers to discuss everything from neighborhood gossip to global politics. In these moments, the hierarchy is clear yet fluid—elders are respected for their wisdom, while the younger generation brings in the pulse of the changing world. The Modern Pivot: Balancing Tradition and Tech
Even if both parents work high-powered jobs, by 7:00 PM, the kitchen comes alive. It is a rare Indian family that eats pre-packaged microwave dinners. The act of cooking is an act of love.
In recent years, the Indian family lifestyle has undergone significant changes. Urbanization, modernization, and migration have led to a shift away from the traditional joint family system. Nuclear families are becoming more common, and family values are evolving to adapt to changing times. Despite these challenges, Indian families continue to hold dear their cultural heritage and traditions.
From the daily drama of matching socks in the morning to the grand spectacles of multi-day wedding celebrations, the Indian family remains a vibrant, evolving institution—adapting fluidly to the future while keeping its roots firmly planted in the rich soil of its heritage.
The Indian day begins early, often announced by the sharp whistle of a pressure cooker or the rhythmic sweeping of the front porch. In many households, the first person awake is a grandparent, starting their morning with quiet prayers, yoga, or devotional music playing softly in the background.
Even outside of major holidays, weekends are dedicated to the extended family. Sunday lunches at a maternal grandmother's house or attending a relative’s distant cousin's wedding are mandatory social obligations. The concept of "personal space" is frequently traded for the warmth of collective belonging. Navigating the Modern Tug-of-War
The Rhythms of the Indian Home: A Tapestry of Tradition and Tomorrow
: Smartphones and high-speed internet have transformed consumption patterns, sometimes creating silences in once-boisterous living rooms.
Today, the lifestyle is evolving. You’ll see the "Swiggy" delivery boy arriving alongside the traditional vegetable vendor. You’ll see families on Zoom calls with relatives in the US or UK, maintaining the "global Indian family" connection.
: Many families practice internal cleansing through yoga, meditation, or daily prayer at a home altar ( puja ) before starting work or school.
Focuses on the universal chaos of an Indian household. The day starts with the rhythmic whistle of a pressure cooker and the smell of tempering spices (tadka). Grandparents are doing yoga or prayers, parents are rushing to pack lunch boxes (the "tiffin wars"), and the kids are hunting for missing socks. It’s loud, it’s frantic, but it’s fueled by hot chai and shared goals. 2. The Multi-Generational Bond (Heartfelt & Traditional)
No story about Indian family lifestyle is complete without the "Morning Queue." In a household of six—Grandparents, parents, two kids, and an unmarried Chacha (uncle)—the single bathroom is a sovereign territory.
The on-disk layouts used by the current 2.6 cryptoloop are supported by dm-crypt.
Cryptoloop also uses cryptoapi so the name of the ciphers are the same. Cryptoloop also
supports ECB and CBC mode. Use <cipher>-ecb and
<cipher>-plain accordingly with dm-crypt. If you didn't
explicitly specify either -ecb or -cbc before you don't need it now, the default plain
IV generation will be used. There will be additional (incompatible, but more secure) possibilites
in the future because the unhashed sector number as IV is too predictible.
You'll need to figure out how your passphrase was turned into a key to use for losetup.
There are several patches floating around doing things differently. But usually cryptsetup
will provide a working solution to recreate the same key from your passphrase.
If you want to migrate from 2.4 cryptoloop please take a look at Clemens Fruhwirth's
Cryptoloop
Migration Guide. He describes the differences between 2.4 and 2.6 cryptoapi (or basically
the bugs in 2.4 cryptoapi...). If you need to cut the key size you can use the -s
option instead of playing with dd.
(BTW: Clemens has a i586 optimized version of the aes and serpent cipher on his page,
about twice as fast as the kernel implementation.)
Why dm-crypt?
Originally it started as a fun project because I wanted to play with the new Linux 2.6 internals.
I got a lot of great help from the device-mapper guys at Sistina (now Redhat). Thank you very
much!
It turned out that this implementation worked great and is very clean compared to the hacked
loop device. The device-mapper core provides much better facilities to stack block devices.
dm-crypt uses mempools to assure we never run into out-of-memory deadlocks when allocating
buffers.
Also the device-mapper configuration interface provides much more flexibility than the losetup
ioctl. And you can create as many devices as you want with any names you want and combine them
with other dm targets. Online device resizing is also possible, e.g. if you use dm-crypt on top
of a logical volume. There might perhaps even be LVM or EVMS support for device encryption
in the future.
It is impossible to discuss the Indian family lifestyle without mentioning festivals. The calendar is dotted with celebrations—Diwali, Eid, Eid-ul-Fitr, Christmas, Navratri, Pongal, and Durga Puja, to name just a few.
Evening stories often happen around the "tea table." This is when the family gathers to discuss everything from neighborhood gossip to global politics. In these moments, the hierarchy is clear yet fluid—elders are respected for their wisdom, while the younger generation brings in the pulse of the changing world. The Modern Pivot: Balancing Tradition and Tech
Even if both parents work high-powered jobs, by 7:00 PM, the kitchen comes alive. It is a rare Indian family that eats pre-packaged microwave dinners. The act of cooking is an act of love.
In recent years, the Indian family lifestyle has undergone significant changes. Urbanization, modernization, and migration have led to a shift away from the traditional joint family system. Nuclear families are becoming more common, and family values are evolving to adapt to changing times. Despite these challenges, Indian families continue to hold dear their cultural heritage and traditions. It is impossible to discuss the Indian family
From the daily drama of matching socks in the morning to the grand spectacles of multi-day wedding celebrations, the Indian family remains a vibrant, evolving institution—adapting fluidly to the future while keeping its roots firmly planted in the rich soil of its heritage.
The Indian day begins early, often announced by the sharp whistle of a pressure cooker or the rhythmic sweeping of the front porch. In many households, the first person awake is a grandparent, starting their morning with quiet prayers, yoga, or devotional music playing softly in the background.
Even outside of major holidays, weekends are dedicated to the extended family. Sunday lunches at a maternal grandmother's house or attending a relative’s distant cousin's wedding are mandatory social obligations. The concept of "personal space" is frequently traded for the warmth of collective belonging. Navigating the Modern Tug-of-War In these moments, the hierarchy is clear yet
The Rhythms of the Indian Home: A Tapestry of Tradition and Tomorrow
: Smartphones and high-speed internet have transformed consumption patterns, sometimes creating silences in once-boisterous living rooms.
Today, the lifestyle is evolving. You’ll see the "Swiggy" delivery boy arriving alongside the traditional vegetable vendor. You’ll see families on Zoom calls with relatives in the US or UK, maintaining the "global Indian family" connection. The act of cooking is an act of love
: Many families practice internal cleansing through yoga, meditation, or daily prayer at a home altar ( puja ) before starting work or school.
Focuses on the universal chaos of an Indian household. The day starts with the rhythmic whistle of a pressure cooker and the smell of tempering spices (tadka). Grandparents are doing yoga or prayers, parents are rushing to pack lunch boxes (the "tiffin wars"), and the kids are hunting for missing socks. It’s loud, it’s frantic, but it’s fueled by hot chai and shared goals. 2. The Multi-Generational Bond (Heartfelt & Traditional)
No story about Indian family lifestyle is complete without the "Morning Queue." In a household of six—Grandparents, parents, two kids, and an unmarried Chacha (uncle)—the single bathroom is a sovereign territory.
Please contact the mailing list: dm-crypt@saout.de. Or in case there is a problem with the mailing list, me: .