Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r257539:

When zero'ing out a buffer, make sure we are using right size.

Without this change, in the worst but unlikely case scenario, certain
administrative operations, including change of configuration, set or
delete key from a GEOM ELI provider, may leave potentially sensitive
information in buffer allocated from kernel memory.

We believe that it is not possible to actively exploit these issues, nor
does it impact the security of normal usage of GEOM ELI providers when
these operations are not performed after system boot.

Security: possible sensitive information disclosure
Submitted by: Clement Lecigne <clecigne google com>
Approved by: re (glebius)

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Use correct part of the Master-Key for generating encryption keys.
Before this change the IV-Key was used to generate encryption keys,
which was incorrect, but safe - for the XTS mode this key was unused
anyway and for CBC mode it was used differently to generate IV
vectors, so there is no risk that IV vector collides with encryption
key somehow.

Bump version number and keep compatibility for older versions.

MFC after: 2 weeks

Version 6 is compatible with version 5 when it comes to control commands.

MFC after: 1 week

Instead of allocating memory for all the keys at device attach,
create reasonably large cache for the keys that is filled when
needed. The previous version was problematic for very large providers
(hundreds of terabytes or serval petabytes). Every terabyte of data
needs around 256kB for keys. Make the default cache limit big enough
to fit all the keys needed for 4TB providers, which will eat at most
1MB of memory.

MFC after: 2 weeks

- Improve error messages, so instead of 'Not fully done', the user will get
information that device is already suspended or that device is using
one-time key and suspend is not supported.
- 'geli suspend -a' silently skips devices that use one-time key, this is fine,
but because we log which device were suspended on the console, log also which
devices were skipped.

Close a race between checking if device is already suspended and suspending it.

Move sc_akeyctx and sc_ivctx initialization to the g_eli_mkey_propagate()
function which eliminates code duplication and will ensure proper order
of operation.

Bring in geli suspend/resume functionality (finally).

Before this change if you wanted to suspend your laptop and be sure that your
encryption keys are safe, you had to stop all processes that use file system
stored on encrypted device, unmount the file system and detach geli provider.

This isn't very handy. If you are a lucky user of a laptop where suspend/resume
actually works with FreeBSD (I'm not!) you most likely want to suspend your
laptop, because you don't want to start everything over again when you turn
your laptop back on.

And this is where geli suspend/resume steps in. When you execute:

# geli suspend -a

geli will wait for all in-flight I/O requests, suspend new I/O requests, remove
all geli sensitive data from the kernel memory (like encryption keys) and will
wait for either 'geli resume' or 'geli detach'.

Now with no keys in memory you can suspend your laptop without stopping any
processes or unmounting any file systems.

When you resume your laptop you have to resume geli devices using 'geli resume'
command. You need to provide your passphrase, etc. again so the keys can be
restored and suspended I/O requests released.

Of course you need to remember that 'geli suspend' won't clear file system
cache and other places where data from your geli-encrypted file system might be
present. But to get rid of those stopping processes and unmounting file system
won't help either - you have to turn your laptop off. Be warned.

Also note, that suspending geli device which contains file system with geli
utility (or anything used by 'geli resume') is not very good idea, as you won't
be able to resume it - when you execute geli(8), the kernel will try to read it
and this read I/O request will be suspended.

Ignore errors from BIO_FLUSH. It might confuse users that provider wasn't
really killed. What we really care about are write errors only.

MFC after: 2 weeks

Update copyright years.

MFC after: 1 week

When trashing metadata, flush after each write.

MFC after: 1 week

- Allow to specify value as const pointers.
- Make optional string values always an empty string.

When deleting key, flush write cache after each overwrite, so we don't
overwrite data N times in cache and only once on disk.

Warn when user use sectorsize bigger than the page size, which will lead
to problems when the geli device is used with file system or as a swap.

Hopefully will prevent problems like kern/98742 in the future.

MFC after: 1 week

Remove trailing spaces.

Add 'configure' subcommand which for now only allows setting and removing
of the BOOT flag. It can be performed on both attached and detached
providers.

Requested by: Matthias Lederhofer <matled@gmx.net>
MFC after: 1 week

Remove extra arguments.

MFC after: 3 days

Allow geli to operate on read-only providers.

Initial patch from: vd
MFC after: 2 weeks

Allow to use the old -a option to specify an encryption algorithm to use
(for backward compatibility), but print a warning to inform about the
change.

Implement data integrity verification (data authentication) for geli(8).

Supported by: Wheel Sp. z o.o. (http://www.wheel.pl)

Remove trailing spaces.

- Use better types.
- Log problems at level 0 when killing providers.

MFC after: 3 days

Check return value.

Found by: Coverity Prevent(tm)
MFC after: 3 days

Allow to change number of iterations for PKCS#5v2. It can only be used
when there is only one key set.

MFC after: 3 days

Add GEOM_ELI class which provides GEOM providers encryption.
For features list and usage see manual page: geli(8).

Sponsored by: Wheel Sp. z o.o.
http://www.wheel.pl
MFC after: 1 week