FM / cryptsetup

/usr/share/doc/cryptsetup

Name	Size	Mode	Actions
examples/	-	0755	rm
AUTHORS	137	0644	edit dl rm
changelog.Debian.gz	2251	0644	edit dl rm
copyright	9292	0644	edit dl rm
FAQ.gz	48990	0644	edit dl rm
Keyring.txt	2724	0644	edit dl rm
LUKS2-locking.txt	2711	0644	edit dl rm
NEWS.Debian.gz	1057	0644	edit dl rm
README.Debian.gz	5680	0644	edit dl rm
README.debug	2731	0644	edit dl rm
README.gnupg	1848	0644	edit dl rm
README.gnupg-sc	2354	0644	edit dl rm
README.keyctl	3583	0644	edit dl rm
README.md.gz	2223	0644	edit dl rm
README.opensc.gz	2219	0644	edit dl rm
v1.0.7-ReleaseNotes	2921	0644	edit dl rm
v1.1.0-ReleaseNotes.gz	2275	0644	edit dl rm
v1.1.1-ReleaseNotes	1796	0644	edit dl rm
v1.1.2-ReleaseNotes	1594	0644	edit dl rm
v1.1.3-ReleaseNotes	482	0644	edit dl rm
v1.2.0-ReleaseNotes.gz	2124	0644	edit dl rm
v1.3.0-ReleaseNotes.gz	2134	0644	edit dl rm
v1.3.1-ReleaseNotes	421	0644	edit dl rm
v1.4.0-ReleaseNotes.gz	2253	0644	edit dl rm
v1.4.1-ReleaseNotes	889	0644	edit dl rm
v1.4.2-ReleaseNotes	1630	0644	edit dl rm
v1.4.3-ReleaseNotes	2359	0644	edit dl rm
v1.5.0-ReleaseNotes.gz	3320	0644	edit dl rm
v1.5.1-ReleaseNotes	1295	0644	edit dl rm
v1.6.0-ReleaseNotes.gz	3818	0644	edit dl rm
v1.6.1-ReleaseNotes	1041	0644	edit dl rm
v1.6.2-ReleaseNotes	985	0644	edit dl rm
v1.6.3-ReleaseNotes	1859	0644	edit dl rm
v1.6.4-ReleaseNotes	2036	0644	edit dl rm
v1.6.5-ReleaseNotes	2479	0644	edit dl rm
v1.6.6-ReleaseNotes	1093	0644	edit dl rm
v1.6.7-ReleaseNotes	3333	0644	edit dl rm
v1.6.8-ReleaseNotes	2061	0644	edit dl rm
v1.7.0-ReleaseNotes	3101	0644	edit dl rm
v1.7.1-ReleaseNotes	1371	0644	edit dl rm
v1.7.2-ReleaseNotes	1487	0644	edit dl rm
v1.7.3-ReleaseNotes	811	0644	edit dl rm
v1.7.4-ReleaseNotes	657	0644	edit dl rm
v1.7.5-ReleaseNotes	833	0644	edit dl rm
v2.0.0-ReleaseNotes.gz	9728	0644	edit dl rm
v2.0.1-ReleaseNotes.gz	2226	0644	edit dl rm
v2.0.2-ReleaseNotes.gz	1992	0644	edit dl rm
v2.0.3-ReleaseNotes.gz	2448	0644	edit dl rm
v2.0.4-ReleaseNotes.gz	2325	0644	edit dl rm
v2.0.5-ReleaseNotes.gz	2068	0644	edit dl rm
v2.0.6-ReleaseNotes.gz	1960	0644	edit dl rm
v2.1.0-ReleaseNotes.gz	3484	0644	edit dl rm
v2.2.0-ReleaseNotes.gz	4582	0644	edit dl rm
v2.2.1-ReleaseNotes	1413	0644	edit dl rm
v2.2.2-ReleaseNotes	2151	0644	edit dl rm
v2.3.0-ReleaseNotes.gz	3250	0644	edit dl rm
v2.3.1-ReleaseNotes	1770	0644	edit dl rm
v2.3.2-ReleaseNotes	1499	0644	edit dl rm
v2.3.3-ReleaseNotes	1396	0644	edit dl rm
v2.3.4-ReleaseNotes.gz	2001	0644	edit dl rm
v2.3.5-ReleaseNotes.gz	3129	0644	edit dl rm
v2.3.6-ReleaseNotes	2316	0644	edit dl rm
v2.4.0-ReleaseNotes.gz	4766	0644	edit dl rm
v2.4.1-ReleaseNotes	1942	0644	edit dl rm
v2.4.2-ReleaseNotes	1375	0644	edit dl rm
v2.4.3-ReleaseNotes.gz	1996	0644	edit dl rm

Edit: /usr/share/doc/cryptsetup/README.gnupg-sc (2354B)

Using an OpenPGP smartcard for LUKS dm-crypt devices in Debian
==============================================================

The Debian cryptsetup package provides the keyscript `decrypt_gnupg-sc`
for setups with a keyfile that is encrypted using an OpenPGP smartcard.

The following example assumes that you store the encrypted keyfile in
`/etc/keys/cryptkey.gpg`. LUKS device is `/dev/<luks_device>`.

First, you'll have to create the keyfile and encrypt it with your key
0xDEADBEEF:

dd if=/dev/random bs=1 count=256 | gpg --recipient 0xDEADBEEF \
            --output /etc/keys/cryptkey.gpg --encrypt

Next the LUKS device needs to be formated with the key. For that, the
`decrypt_gnupg-sc` keyscript can be used:

/lib/cryptsetup/scripts/decrypt_gnupg-sc /etc/keys/cryptkey.gpg | \
            cryptsetup --key-file=- luksFormat /dev/<luks_device>

In order to unlock the encrypted LUKS device automatically during boot process,
add the following to `/etc/crypttab`:

cdev1   /dev/<luks_device>      /etc/keys/cryptkey.gpg luks,keyscript=decrypt_gnupg-sc

In order to avoid data loss if the smartcard is damaged or lost, you may
want to decrypt `/etc/keys/cryptkey.gpg` and store the plaintext in a safe
place.  Or alternatively, use another slot with your backup key:

cryptsetup luksAddKey /dev/<luks_device> /path/to/backup.key

Decrypting the keyfile at initramfs stage
-----------------------------------------

If the device is to be unlocked at initramfs stage (such as for the root
FS or the resume device), you need to copy the public part of the
encryption key to `/etc/cryptsetup-initramfs/pubring.gpg`:

gpg --export 0xDEADBEEF >/etc/cryptsetup-initramfs/pubring.gpg

Then the provided initramfs hooks should do all additionally required
work for you when the initramfs is created or updated.

Be warned though, that for such devices the OpenPGP encrypted key is copied
to the initramfs by the initramfs cryptgnupg-sc hook. If you don't want this,
you should take a look at the initramfs cryptgnupg-sc hook, which is located
at `/usr/share/initramfs-tools/hooks/cryptgnupg-sc`.

Moreover, note that unlocking at initramfs stage is currently not compatible
with plymouth or other bootsplash, as a curses-based prompt is used for PIN
entry.

-- Guilhem Moulin <guilhem@guilhem.org>  Sun, 23 Sep 2018 03:28:31 +0200

cmd: