NAME¶

SYNOPSIS¶

geom_eli_load="YES"

DESCRIPTION¶

• Utilizes the crypto(9) framework, so when there is crypto hardware available, geli will make use of it automatically.
• Supports many cryptographic algorithms (currently AES-XTS, AES-CBC, Blowfish-CBC, Camellia-CBC and 3DES-CBC).
• Can optionally perform data authentication (integrity verification) utilizing one of the following algorithms: HMAC/MD5, HMAC/SHA1, HMAC/RIPEMD160, HMAC/SHA256, HMAC/SHA384 or HMAC/SHA512.
• Can create a key from a couple of components (user entered passphrase, random bits from a file, etc.).
• Allows to encrypt the root partition - the user will be asked for the passphrase before the root file system is mounted.
• The passphrase of the user is strengthened with: B. Kaliski, PKCS #5: Password-Based Cryptography Specification, Version 2.0., RFC, 2898.
• Allows to use two independent keys (e.g. “user key” and “company key”).
• It is fast - geli performs simple sector-to-sector encryption.
• Allows to backup/restore Master Keys, so when a user has to quickly destroy his keys, it is possible to get the data back by restoring keys from the backup.
• Providers can be configured to automatically detach on last close (so users do not have to remember to detach providers after unmounting the file systems).
• Allows to attach a provider with a random, one-time key - useful for swap partitions and temporary file systems.
• Allows to verify data integrity (data authentication).
• Allows to suspend and resume encrypted devices.

init

Initialize provider which needs to be encrypted. Here you can set up the cryptographic algorithm to use, key length, etc. The last provider's sector is used to store metadata. The init subcommand also automatically backups metadata in /var/backups/<prov>.eli file. The metadata can be recovered with the restore subcommand described below.

Additional options include:

-a aalgo

Enable data integrity verification (authentication) using the given algorithm. This will reduce size of available storage and also reduce speed. For example, when using 4096 bytes sector and HMAC/SHA256 algorithm, 89% of the original provider storage will be available for use. Currently supported algorithms are: HMAC/MD5, HMAC/SHA1, HMAC/RIPEMD160, HMAC/SHA256, HMAC/SHA384 and HMAC/SHA512. If the option is not given, there will be no authentication, only encryption. The recommended algorithm is HMAC/SHA256.

-b

Ask for the passphrase on boot, before the root partition is mounted. This makes it possible to use an encrypted root partition. One will still need bootable unencrypted storage with a /boot/ directory, which can be a CD-ROM disc or USB pen-drive, that can be removed after boot.

-B backupfile

File name to use for metadata backup instead of the default /var/backups/<prov>.eli. To inhibit backups, you can use none as the backupfile.

-e ealgo

Encryption algorithm to use. Currently supported algorithms are: AES-XTS, AES-CBC, Blowfish-CBC, Camellia-CBC and 3DES-CBC. The default and recommended algorithm is AES-XTS.

-i iterations

Number of iterations to use with PKCS#5v2. If this option is not specified, geli will find the number of iterations which is equal to 2 seconds of crypto work. If 0 is given, PKCS#5v2 will not be used.

-J newpassfile

Specifies a file which contains the passphrase or its part. If newpassfile is given as -, standard input will be used. Only the first line (excluding new-line character) is taken from the given file. This argument can be specified multiple times.

-K newkeyfile

Specifies a file which contains part of the key. If newkeyfile is given as -, standard input will be used. This argument can be specified multiple times.

-l keylen

Key length to use with the given cryptographic algorithm. If not given, the default key length for the given algorithm is used, which is: 128 for AES-XTS, AES-CBC, Blowfish-CBC and Camellia-CBC and 192 for 3DES-CBC.

-P

Do not use passphrase as the key component.

-s sectorsize

Change decrypted provider's sector size. Increasing sector size allows to increase performance, because we need to generate an IV and do encrypt/decrypt for every single sector - less number of sectors means less work to do.

attach

Attach the given provider. The master key will be decrypted using the given passphrase/keyfile and a new GEOM provider will be created using the given provider's name with an “.eli” suffix.

Additional options include:

-d

If specified, a decrypted provider will be detached automatically on last close. This can help with short memory - user does not have to remember to detach the provider after unmounting the file system. It only works when the provider was opened for writing, so it will not work if the file system on the provider is mounted read-only. Probably a better choice is the -l option for the detach subcommand.

-j passfile

Specifies a file which contains the passphrase or its part. For more information see the description of the -J option for the init subcommand.

-k keyfile

Specifies a file which contains part of the key. For more information see the description of the -K option for the init subcommand.

-p

Do not use passphrase as the key component.

-r

Attach read-only provider. It will not be opened for writing.

detach

Detach the given providers, which means remove the devfs entry and clear the keys from memory.

Additional options include:

-f

Force detach - detach even if the provider is open.

-l

Mark provider to detach on last close. If this option is specified, the provider will not be detached until it is open, but when it will be closed last time, it will be automatically detached (even if it was only opened for reading).

onetime

Attach the given providers with random, one-time keys. The command can be used to encrypt swap partitions or temporary file systems.

Additional options include:

-a aalgo

Enable data integrity verification (authentication). For more information, see the description of the init subcommand.

-e ealgo

Encryption algorithm to use. For more information, see the description of the init subcommand.

-d

Detach on last close. Note, the option is not usable for temporary file systems as the provider will be detached after creating the file system on it. It still can (and should be) used for swap partitions. For more information, see the description of the attach subcommand.

-l keylen

Key length to use with the given cryptographic algorithm. For more information, see the description of the init subcommand.

-s sectorsize

Change decrypted provider's sector size. For more information, see the description of the init subcommand.

configure

Change configuration of the given providers.

Additional options include:

-b

Set the BOOT flag on the given providers. For more information, see the description of the init subcommand.

-B

Remove the BOOT flag from the given providers.

setkey

Change or setup (if not yet initialized) selected key. There is one master key, which can be encrypted with two independent user keys. With the init subcommand, only key number 0 is initialized. The key can always be changed: for an attached provider, for a detached provider or on the backup file. When a provider is attached, the user does not have to provide an old passphrase/keyfile.

Additional options include:

-i iterations

Number of iterations to use with PKCS#5v2. If 0 is given, PKCS#5v2 will not be used. To be able to use this option with setkey subcommand, only one key have to be defined and this key has to be changed.

-j passfile

Specifies a file which contains the old passphrase or its part.

-J newpassfile

Specifies a file which contains the new passphrase or its part.

-k keyfile

Specifies a file which contains part of the old key.

-K newkeyfile

Specifies a file which contains part of the new key.

-n keyno

Specifies the number of the key to change (could be 0 or 1). If the provider is attached and no key number is given, the key used for attaching the provider will be changed. If the provider is detached (or we are operating on a backup file) and no key number is given, the key decrypted with the passphrase/keyfile will be changed.

-p

Do not use passphrase as the old key component.

-P

Do not use passphrase as the new key component.

delkey

Destroy (overwrite with random data) the selected key. If one is destroying keys for an attached provider, the provider will not be detached even if all keys will be destroyed. It can be even rescued with the setkey subcommand.

Additional options include:

-a

Destroy all keys (does not need -f option).

-f

Force key destruction. This option is needed to destroy the last key.

-n keyno

Specifies the key number. If the provider is attached and no key number is given, the key used for attaching the provider will be destroyed. If provider is detached (or we are operating on a backup file) the key number has to be given.

kill

This command should be used in emergency situations. It will destroy all keys on the given provider and will detach it forcibly (if it is attached). This is absolutely a one-way command - if you do not have a metadata backup, your data is gone for good. In case the provider was attached with the -r flag, the keys will not be destroyed, only the provider will be detached.

Additional options include:

-a

If specified, all currently attached providers will be killed.

backup

Backup metadata from the given provider to the given file.

restore

Restore metadata from the given file to the given provider.

Additional options include:

-f

Metadata contains the size of the provider to ensure that the correct partition or slice is attached. If an attempt is made to restore metadata to a provider that has a different size, geli will refuse to restore the data unless the -f switch is used. If the partition or slice has been grown, the resize subcommand should be used rather than attempting to relocate the metadata through backup and restore.

suspend

Suspend device by waiting for all inflight request to finish, clearing all sensitive informations (like keys) from the kernel memory and blocking all further I/O requests until the resume subcommand is executed. This functionality is useful for eg. laptops - when one wants to suspend a laptop, one does not want to leave encrypted device attached. Instead of closing all files and directories opened from a file system placed on an encrypted device, unmounting the file system and detaching the device, the suspend subcommand can be used. Any access to the encrypted device will be blocked until the keys are recovered through resume subcommand, thus there is no need to close nor unmount anything. The suspend subcommand does not work with devices created with the onetime subcommand. Please note that sensitive data might still be present in memory after suspending encrypted device, because of file system cache, etc.

Additional options include:

-a

Suspend all geli devices.

resume

Resume previously suspended device. The caller must ensure that executing this subcommand won't try to access suspended device, which will lead to a deadlock. For example suspending device, which contains file system where the geli utility is stored is bad idea.

Additional options include:

-j passfile

Specifies a file which contains the passphrase or its part. For more information see the description of the -J option for the init subcommand.

-k keyfile

Specifies a file which contains part of the key. For more information see the description of the -K option for the init subcommand.

-p

Do not use passphrase as the key component.

resize

Inform geli that the provider has been resized. The old metadata block is relocated to the correct position at the end of the provider and the provider size is updated.

Additional options include:

-s oldsize

The size of the provider before it was resized.

clear

Clear metadata from the given providers.

dump

Dump metadata stored on the given providers.

list

See geom(8).

status

See geom(8).

load

See geom(8).

unload

See geom(8).

-v

Be more verbose.

SYSCTL VARIABLES¶

kern.geom.eli.version

Version number of the ELI GEOM class.

kern.geom.eli.debug: 0

Debug level of the ELI GEOM class. This can be set to a number between 0 and 3 inclusive. If set to 0, minimal debug information is printed. If set to 3, the maximum amount of debug information is printed.

kern.geom.eli.tries: 3

Number of times a user is asked for the passphrase. This is only used for providers which should be attached on boot (before the root file system is mounted). If set to 0, attaching providers on boot will be disabled. This variable should be set in /boot/loader.conf.

kern.geom.eli.overwrites: 5

Specifies how many times the Master-Key will be overwritten with random values when it is destroyed. After this operation it is filled with zeros.

kern.geom.eli.visible_passphrase: 0

If set to 1, the passphrase entered on boot (before the root file system is mounted) will be visible. This possibility should be used with caution as the entered passphrase can be logged and exposed via dmesg(8). This variable should be set in /boot/loader.conf.

kern.geom.eli.threads: 0

Specifies how many kernel threads should be used for doing software cryptography. Its purpose is to increase performance on SMP systems. If hardware acceleration is available, only one thread will be started. If set to 0, CPU-bound thread will be started for every active CPU.

kern.geom.eli.batch: 0

When set to 1, can speed-up crypto operations by using batching. Batching allows to reduce number of interrupts by responding on a group of crypto requests with one interrupt. The crypto card and the driver has to support this feature.

kern.geom.eli.key_cache_limit: 8192

Specifies how many encryption keys to cache. The default limit (8192 keys) will allow to cache all keys for 4TB provider with 512 bytes sectors and will take around 1MB of memory.

kern.geom.eli.key_cache_hits

Reports how many times we were looking up a key and it was already in cache. This sysctl is not updated for providers that need less keys than the limit specified in kern.geom.eli.key_cache_limit.

kern.geom.eli.key_cache_misses

Reports how many times we were looking up a key and it was not in cache. This sysctl is not updated for providers that need less keys than the limit specified in kern.geom.eli.key_cache_limit.

EXIT STATUS¶

EXAMPLES¶

# dd if=/dev/random of=/mnt/pendrive/da2.key bs=64 count=1 
# geli init -s 4096 -K /mnt/pendrive/da2.key /dev/da2 
Enter new passphrase: 
Reenter new passphrase: 
# geli attach -k /mnt/pendrive/da2.key /dev/da2 
Enter passphrase: 
# dd if=/dev/random of=/dev/da2.eli bs=1m 
# newfs /dev/da2.eli 
# mount /dev/da2.eli /mnt/secret 
... 
# umount /mnt/secret 
# geli detach da2.eli

# geli init /dev/da2 
Enter new passphrase:	(enter security officer passphrase) 
Reenter new passphrase: 
# geli setkey -n 1 /dev/da2 
Enter passphrase:	(enter security officer passphrase) 
Enter new passphrase:	(let your employee enter his passphrase ...) 
Reenter new passphrase:	(... twice)

# dd if=/dev/random of=/mnt/pendrive/keys/`hostname` bs=64 count=1 
# geli init -P -K /mnt/pendrive/keys/`hostname` /dev/ad0s1e 
# geli backup /dev/ad0s1e /mnt/pendrive/backups/`hostname` 
(use key number 0, so the encrypted Master Key by you will be overwritten) 
# geli setkey -n 0 -k /mnt/pendrive/keys/`hostname` /dev/ad0s1e 
(allow the user to enter his passphrase) 
Enter new passphrase: 
Reenter new passphrase:

# dd if=/dev/random of=/dev/ad0s1b bs=1m 
# geli onetime -d -e 3des ad0s1b 
# swapon /dev/ad0s1b.eli

# dd if=/dev/random of=/dev/da0 bs=1m 
# dd if=/dev/random of=/boot/keys/da0.key0 bs=32k count=1 
# dd if=/dev/random of=/boot/keys/da0.key1 bs=32k count=1 
# dd if=/dev/random of=/boot/keys/da0.key2 bs=32k count=1 
# geli init -b -K /boot/keys/da0.key0 -K /boot/keys/da0.key1 -K /boot/keys/da0.key2 da0 
Enter new passphrase: 
Reenter new passphrase: 
# dd if=/dev/random of=/dev/da1s3a bs=1m 
# dd if=/dev/random of=/boot/keys/da1s3a.key bs=128k count=1 
# geli init -b -P -K /boot/keys/da1s3a.key da1s3a

geli_da0_keyfile0_load="YES" 
geli_da0_keyfile0_type="da0:geli_keyfile0" 
geli_da0_keyfile0_name="/boot/keys/da0.key0" 
geli_da0_keyfile1_load="YES" 
geli_da0_keyfile1_type="da0:geli_keyfile1" 
geli_da0_keyfile1_name="/boot/keys/da0.key1" 
geli_da0_keyfile2_load="YES" 
geli_da0_keyfile2_type="da0:geli_keyfile2" 
geli_da0_keyfile2_name="/boot/keys/da0.key2" 
 
geli_da1s3a_keyfile0_load="YES" 
geli_da1s3a_keyfile0_type="da1s3a:geli_keyfile0" 
geli_da1s3a_keyfile0_name="/boot/keys/da1s3a.key"

# geli init -a hmac/sha256 -s 4096 /dev/da0 
Enter new passphrase: 
Reenter new passphrase: 
# geli attach /dev/da0 
Enter passphrase: 
# dd if=/dev/random of=/dev/da0.eli bs=1m 
# newfs /dev/da0.eli 
# mount /dev/da0.eli /mnt/secret

# geli init /dev/da0 
Enter new passphrase: 
Reenter new passphrase: 
 
Metadata backup can be found in /var/backups/da0.eli and 
can be restored with the following command: 
 
	# geli restore /var/backups/da0.eli /dev/da0 
 
# geli clear /dev/da0 
# geli attach /dev/da0 
geli: Cannot read metadata from /dev/da0: Invalid argument. 
# geli restore /var/backups/da0.eli /dev/da0 
# geli attach /dev/da0 
Enter passphrase:

# gpart create -s GPT ada0 
# gpart add -s 1g -t freebsd-ufs -i 1 ada0 
# geli init -K keyfile -P ada0p1 
# gpart resize -s 2g -i 1 ada0 
# geli resize -s 1g ada0p1 
# geli attach -k keyfile -p ada0p1

# echo foo > da0.pass0 
# echo bar > da0.pass1 
# geli init -J da0.pass0 -J da0.pass1 da0 
# geli attach -j da0.pass0 -j da0.pass1 da0 
# geli detach da0 
# geli attach da0 
Enter passphrase: foobar

# geli suspend -a 
# zzz 
<resume your laptop> 
# geli resume -p -k keyfile gpt/secret 
# geli resume gpt/private 
Enter passphrase:

ENCRYPTION MODES¶

DATA AUTHENTICATION¶

SEE ALSO¶

HISTORY¶

AUTHORS¶