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GELI(8)			  BSD System Manager's Manual		       GELI(8)

NAME
     geli — control utility for cryptographic GEOM class

SYNOPSIS
     To compile GEOM_ELI into your kernel, place the following lines in your
     kernel configuration file:

	   device crypto
	   options GEOM_ELI

     Alternately, to load the GEOM_ELI module at boot time, place the follow‐
     ing line in your loader.conf(5):

	   geom_eli_load="YES"

     Usage of the geli(8) utility:

     geli init [-bPv] [-a aalgo] [-B backupfile] [-e ealgo] [-i iterations]
	   [-J newpassfile] [-K newkeyfile] [-l keylen] [-s sectorsize] prov
     geli label - an alias for init
     geli attach [-dprv] [-j passfile] [-k keyfile] prov
     geli detach [-fl] prov ...
     geli stop - an alias for detach
     geli onetime [-d] [-a aalgo] [-e ealgo] [-l keylen] [-s sectorsize] prov
     geli configure [-bB] prov ...
     geli setkey [-pPv] [-i iterations] [-j passfile] [-J newpassfile]
	   [-k keyfile] [-K newkeyfile] [-n keyno] prov
     geli delkey [-afv] [-n keyno] prov
     geli kill [-av] [prov ...]
     geli backup [-v] prov file
     geli restore [-fv] file prov
     geli suspend [-v] -a | prov ...
     geli resume [-pv] [-j passfile] [-k keyfile] prov
     geli resize [-v] -s oldsize prov
     geli clear [-v] prov ...
     geli dump [-v] prov ...
     geli list
     geli status
     geli load
     geli unload

DESCRIPTION
     The geli utility is used to configure encryption on GEOM providers.

     The following is a list of the most important features:

	   ·   Utilizes the crypto(9) framework, so when there is crypto hard‐
	       ware 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 verifica‐
	       tion) 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 - use‐
	       ful for swap partitions and temporary file systems.
	   ·   Allows to verify data integrity (data authentication).
	   ·   Allows to suspend and resume encrypted devices.

     The first argument to geli indicates an action to be performed:

     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 (authenti‐
				cation) 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 avail‐
				able 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 recom‐
				mended algorithm is HMAC/SHA256.

		-b		Ask for the passphrase on boot, before the
				root partition is mounted.  This makes it pos‐
				sible 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 sup‐
				ported 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 per‐
				formance, 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 descrip‐
			     tion 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 (authentica‐
			       tion).  For more information, see the descrip‐
			       tion of the init subcommand.

		-e ealgo       Encryption algorithm to use.  For more informa‐
			       tion, see the description of the init subcom‐
			       mand.

		-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 infor‐
			       mation, see the description of the attach sub‐
			       command.

		-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 infor‐
		    mation, 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 subcom‐
				mand, 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 compo‐
				nent.

		-P		Do not use passphrase as the new key compo‐
				nent.

     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 dif‐
		    ferent 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 ker‐
		nel 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 clos‐
		ing all files and directories opened from a file system placed
		on an encrypted device, unmounting the file system and detach‐
		ing 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 mem‐
		ory 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 descrip‐
			     tion 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 meta‐
		data 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).

     Additional options include:

     -v	 Be more verbose.

SYSCTL VARIABLES
     The following sysctl(8) variables can be used to control the behavior of
     the ELI GEOM class.  The default value is shown next to each variable.
     All variables can also be set in /boot/loader.conf.

     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 informa‐
	     tion is printed.  If set to 3, the maximum amount of debug infor‐
	     mation 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 soft‐
	     ware 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.

EXIT STATUS
     Exit status is 0 on success, and 1 if the command fails.

EXAMPLES
     Initialize a provider which is going to be encrypted with a passphrase
     and random data from a file on the user's pen drive.  Use 4kB sector
     size.  Attach the provider, create a file system and mount it.  Do the
     work.  Unmount the provider and detach it:

	   # 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

     Create an encrypted provider, but use two keys: one for your girlfriend
     and one for you (so there will be no tragedy if she forgets her
     passphrase):

	   # geli init /dev/da2
	   Enter new passphrase:   (enter your passphrase)
	   Reenter new passphrase:
	   # geli setkey -n 1 /dev/da2
	   Enter passphrase:	   (enter your passphrase)
	   Enter new passphrase:   (let your girlfriend enter her passphrase ...)
	   Reenter new passphrase: (... twice)

     You are the security-person in your company.  Create an encrypted
     provider for use by the user, but remember that users forget their
     passphrases, so back Master Key up with your own random key:

	   # 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:

     Encrypted swap partition setup:

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

     The example below shows how to configure two providers which will be
     attached on boot (before the root file system is mounted).	 One of them
     is using passphrase and three keyfiles and the other is using only a key‐
     file:

	   # 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

     The providers are initialized, now we have to add those lines to
     /boot/loader.conf:

	   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"

     Not only configure encryption, but also data integrity verification using
     HMAC/SHA256.

	   # 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 backups metadata by default to the /var/backups/<prov>.eli file.  If
     metadata is lost in any way (eg. by accidental overwrite), it can be
     restored.	Consider the following situation:

	   # 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:

     If an encrypted filesystem is extended, it is necessary to relocate and
     update the metadata:

	   # 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

     Initialize provider with passphrase split into two files.	The provider
     can be attached by giving those two files or by giving “foobar”
     passphrase on geli prompt:

	   # 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

     Suspend all geli devices, suspend a laptop, then resume devices one by
     one after resuming a laptop:

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

ENCRYPTION MODES
     geli supports two encryption modes: XTS, which was standarized as IEE
     P1619 and CBC with unpredictable IV.  The CBC mode used by geli is very
     similar to the mode ESSIV.

DATA AUTHENTICATION
     geli can verify data integrity when an authentication algorithm is speci‐
     fied.  When data corruption/modification is detected, geli will not
     return any data, but instead will return an error (EINVAL).  The offset
     and size of the corrupted data will be printed on the console.  It is
     important to know against which attacks geli provides protection for your
     data.  If data is modified in-place or copied from one place on the disk
     to another even without modification, geli should be able to detect such
     a change.	If an attacker can remember the encrypted data, he can over‐
     write any future changes with the data he owns without notice.  In other
     words geli will not protect your data against replay attacks.

SEE ALSO
     crypto(4), gbde(4), geom(4), loader.conf(5), gbde(8), geom(8), crypto(9)

HISTORY
     The geli utility appeared in FreeBSD 6.0.	Support for Camellia block
     cipher is implemented by Yoshisato Yanagisawa in FreeBSD 7.0.

AUTHORS
     Pawel Jakub Dawidek ⟨pjd@FreeBSD.org⟩

BSD			       October 20, 2010				   BSD
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