Currently, OpenCrypto consumers can request asynchronous dispatch by
setting a flag in the cryptop. (Currently only IPSec may do this.) I
think this is a bit confusing: we (conditionally) set cryptop flags to
request async dispatch, and then crypto_dispatch() immediately examines
those flags to see if the consumer wants async dispatch. The flag names
are also confusing since they don't specify what "async" applies to:
dispatch or completion.
Add a new KPI, crypto_dispatch_async(), rather than encoding the
requested dispatch type in each cryptop. crypto_dispatch_async() falls
back to crypto_dispatch() if the session's driver provides asynchronous
dispatch. Get rid of CRYPTOP_ASYNC() and CRYPTOP_ASYNC_KEEPORDER().
Similarly, add crypto_dispatch_batch() to request processing of a tailq
of cryptops, rather than encoding the scheduling policy using cryptop
flags. Convert GELI, the only user of this interface (disabled by
default) to use the new interface.
Add CRYPTO_SESS_SYNC(), which can be used by consumers to determine
whether crypto requests will be dispatched synchronously. This is just
a helper macro. Use it instead of looking at cap flags directly.
Fix style in crypto_done(). Also get rid of CRYPTO_RETW_EMPTY() and
just check the relevant queues directly. This could result in some
unnecessary wakeups but I think it's very uncommon to be using more than
one queue per worker in a given workload, so checking all three queues
is a waste of cycles.
Reviewed by: jhb
Sponsored by: Ampere Computing
Submitted by: Klara, Inc.
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D28194
Replace MAXPHYS by runtime variable maxphys. It is initialized from
MAXPHYS by default, but can be also adjusted with the tunable kern.maxphys.
Make b_pages[] array in struct buf flexible. Size b_pages[] for buffer
cache buffers exactly to atop(maxbcachebuf) (currently it is sized to
atop(MAXPHYS)), and b_pages[] for pbufs is sized to atop(maxphys) + 1.
The +1 for pbufs allow several pbuf consumers, among them vmapbuf(),
to use unaligned buffers still sized to maxphys, esp. when such
buffers come from userspace (*). Overall, we save significant amount
of otherwise wasted memory in b_pages[] for buffer cache buffers,
while bumping MAXPHYS to desired high value.
Eliminate all direct uses of the MAXPHYS constant in kernel and driver
sources, except a place which initialize maxphys. Some random (and
arguably weird) uses of MAXPHYS, e.g. in linuxolator, are converted
straight. Some drivers, which use MAXPHYS to size embeded structures,
get private MAXPHYS-like constant; their convertion is out of scope
for this work.
Changes to cam/, dev/ahci, dev/ata, dev/mpr, dev/mpt, dev/mvs,
dev/siis, where either submitted by, or based on changes by mav.
Suggested by: mav (*)
Reviewed by: imp, mav, imp, mckusick, scottl (intermediate versions)
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D27225
Some crypto consumers such as GELI and KTLS for file-backed sendfile
need to store their output in a separate buffer from the input.
Currently these consumers copy the contents of the input buffer into
the output buffer and queue an in-place crypto operation on the output
buffer. Using a separate output buffer avoids this copy.
- Create a new 'struct crypto_buffer' describing a crypto buffer
containing a type and type-specific fields. crp_ilen is gone,
instead buffers that use a flat kernel buffer have a cb_buf_len
field for their length. The length of other buffer types is
inferred from the backing store (e.g. uio_resid for a uio).
Requests now have two such structures: crp_buf for the input buffer,
and crp_obuf for the output buffer.
- Consumers now use helper functions (crypto_use_*,
e.g. crypto_use_mbuf()) to configure the input buffer. If an output
buffer is not configured, the request still modifies the input
buffer in-place. A consumer uses a second set of helper functions
(crypto_use_output_*) to configure an output buffer.
- Consumers must request support for separate output buffers when
creating a crypto session via the CSP_F_SEPARATE_OUTPUT flag and are
only permitted to queue a request with a separate output buffer on
sessions with this flag set. Existing drivers already reject
sessions with unknown flags, so this permits drivers to be modified
to support this extension without requiring all drivers to change.
- Several data-related functions now have matching versions that
operate on an explicit buffer (e.g. crypto_apply_buf,
crypto_contiguous_subsegment_buf, bus_dma_load_crp_buf).
- Most of the existing data-related functions operate on the input
buffer. However crypto_copyback always writes to the output buffer
if a request uses a separate output buffer.
- For the regions in input/output buffers, the following conventions
are followed:
- AAD and IV are always present in input only and their
fields are offsets into the input buffer.
- payload is always present in both buffers. If a request uses a
separate output buffer, it must set a new crp_payload_start_output
field to the offset of the payload in the output buffer.
- digest is in the input buffer for verify operations, and in the
output buffer for compute operations. crp_digest_start is relative
to the appropriate buffer.
- Add a crypto buffer cursor abstraction. This is a more general form
of some bits in the cryptosoft driver that tried to always use uio's.
However, compared to the original code, this avoids rewalking the uio
iovec array for requests with multiple vectors. It also avoids
allocate an iovec array for mbufs and populating it by instead walking
the mbuf chain directly.
- Update the cryptosoft(4) driver to support separate output buffers
making use of the cursor abstraction.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D24545
- The linked list of cryptoini structures used in session
initialization is replaced with a new flat structure: struct
crypto_session_params. This session includes a new mode to define
how the other fields should be interpreted. Available modes
include:
- COMPRESS (for compression/decompression)
- CIPHER (for simply encryption/decryption)
- DIGEST (computing and verifying digests)
- AEAD (combined auth and encryption such as AES-GCM and AES-CCM)
- ETA (combined auth and encryption using encrypt-then-authenticate)
Additional modes could be added in the future (e.g. if we wanted to
support TLS MtE for AES-CBC in the kernel we could add a new mode
for that. TLS modes might also affect how AAD is interpreted, etc.)
The flat structure also includes the key lengths and algorithms as
before. However, code doesn't have to walk the linked list and
switch on the algorithm to determine which key is the auth key vs
encryption key. The 'csp_auth_*' fields are always used for auth
keys and settings and 'csp_cipher_*' for cipher. (Compression
algorithms are stored in csp_cipher_alg.)
- Drivers no longer register a list of supported algorithms. This
doesn't quite work when you factor in modes (e.g. a driver might
support both AES-CBC and SHA2-256-HMAC separately but not combined
for ETA). Instead, a new 'crypto_probesession' method has been
added to the kobj interface for symmteric crypto drivers. This
method returns a negative value on success (similar to how
device_probe works) and the crypto framework uses this value to pick
the "best" driver. There are three constants for hardware
(e.g. ccr), accelerated software (e.g. aesni), and plain software
(cryptosoft) that give preference in that order. One effect of this
is that if you request only hardware when creating a new session,
you will no longer get a session using accelerated software.
Another effect is that the default setting to disallow software
crypto via /dev/crypto now disables accelerated software.
Once a driver is chosen, 'crypto_newsession' is invoked as before.
- Crypto operations are now solely described by the flat 'cryptop'
structure. The linked list of descriptors has been removed.
A separate enum has been added to describe the type of data buffer
in use instead of using CRYPTO_F_* flags to make it easier to add
more types in the future if needed (e.g. wired userspace buffers for
zero-copy). It will also make it easier to re-introduce separate
input and output buffers (in-kernel TLS would benefit from this).
Try to make the flags related to IV handling less insane:
- CRYPTO_F_IV_SEPARATE means that the IV is stored in the 'crp_iv'
member of the operation structure. If this flag is not set, the
IV is stored in the data buffer at the 'crp_iv_start' offset.
- CRYPTO_F_IV_GENERATE means that a random IV should be generated
and stored into the data buffer. This cannot be used with
CRYPTO_F_IV_SEPARATE.
If a consumer wants to deal with explicit vs implicit IVs, etc. it
can always generate the IV however it needs and store partial IVs in
the buffer and the full IV/nonce in crp_iv and set
CRYPTO_F_IV_SEPARATE.
The layout of the buffer is now described via fields in cryptop.
crp_aad_start and crp_aad_length define the boundaries of any AAD.
Previously with GCM and CCM you defined an auth crd with this range,
but for ETA your auth crd had to span both the AAD and plaintext
(and they had to be adjacent).
crp_payload_start and crp_payload_length define the boundaries of
the plaintext/ciphertext. Modes that only do a single operation
(COMPRESS, CIPHER, DIGEST) should only use this region and leave the
AAD region empty.
If a digest is present (or should be generated), it's starting
location is marked by crp_digest_start.
Instead of using the CRD_F_ENCRYPT flag to determine the direction
of the operation, cryptop now includes an 'op' field defining the
operation to perform. For digests I've added a new VERIFY digest
mode which assumes a digest is present in the input and fails the
request with EBADMSG if it doesn't match the internally-computed
digest. GCM and CCM already assumed this, and the new AEAD mode
requires this for decryption. The new ETA mode now also requires
this for decryption, so IPsec and GELI no longer do their own
authentication verification. Simple DIGEST operations can also do
this, though there are no in-tree consumers.
To eventually support some refcounting to close races, the session
cookie is now passed to crypto_getop() and clients should no longer
set crp_sesssion directly.
- Assymteric crypto operation structures should be allocated via
crypto_getkreq() and freed via crypto_freekreq(). This permits the
crypto layer to track open asym requests and close races with a
driver trying to unregister while asym requests are in flight.
- crypto_copyback, crypto_copydata, crypto_apply, and
crypto_contiguous_subsegment now accept the 'crp' object as the
first parameter instead of individual members. This makes it easier
to deal with different buffer types in the future as well as
separate input and output buffers. It's also simpler for driver
writers to use.
- bus_dmamap_load_crp() loads a DMA mapping for a crypto buffer.
This understands the various types of buffers so that drivers that
use DMA do not have to be aware of different buffer types.
- Helper routines now exist to build an auth context for HMAC IPAD
and OPAD. This reduces some duplicated work among drivers.
- Key buffers are now treated as const throughout the framework and in
device drivers. However, session key buffers provided when a session
is created are expected to remain alive for the duration of the
session.
- GCM and CCM sessions now only specify a cipher algorithm and a cipher
key. The redundant auth information is not needed or used.
- For cryptosoft, split up the code a bit such that the 'process'
callback now invokes a function pointer in the session. This
function pointer is set based on the mode (in effect) though it
simplifies a few edge cases that would otherwise be in the switch in
'process'.
It does split up GCM vs CCM which I think is more readable even if there
is some duplication.
- I changed /dev/crypto to support GMAC requests using CRYPTO_AES_NIST_GMAC
as an auth algorithm and updated cryptocheck to work with it.
- Combined cipher and auth sessions via /dev/crypto now always use ETA
mode. The COP_F_CIPHER_FIRST flag is now a no-op that is ignored.
This was actually documented as being true in crypto(4) before, but
the code had not implemented this before I added the CIPHER_FIRST
flag.
- I have not yet updated /dev/crypto to be aware of explicit modes for
sessions. I will probably do that at some point in the future as well
as teach it about IV/nonce and tag lengths for AEAD so we can support
all of the NIST KAT tests for GCM and CCM.
- I've split up the exising crypto.9 manpage into several pages
of which many are written from scratch.
- I have converted all drivers and consumers in the tree and verified
that they compile, but I have not tested all of them. I have tested
the following drivers:
- cryptosoft
- aesni (AES only)
- blake2
- ccr
and the following consumers:
- cryptodev
- IPsec
- ktls_ocf
- GELI (lightly)
I have not tested the following:
- ccp
- aesni with sha
- hifn
- kgssapi_krb5
- ubsec
- padlock
- safe
- armv8_crypto (aarch64)
- glxsb (i386)
- sec (ppc)
- cesa (armv7)
- cryptocteon (mips64)
- nlmsec (mips64)
Discussed with: cem
Relnotes: yes
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D23677
GELI used to fail with EINVAL when a read request spanned a disk
sector whose contents did not match the sector's authentication tag.
The recently-added EINTEGRITY more closely matches to the error in
this case.
Reviewed by: cem, mckusick
MFC after: 2 weeks
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D24131
Similar to what was done for device_printfs in r347229.
Convert g_print_bio() to a thin shim around g_format_bio(), which acts on an
sbuf; documented in g_bio.9.
Reviewed by: markj
Discussed with: rlibby
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D21165
Track session objects in the framework, and pass handles between the
framework (OCF), consumers, and drivers. Avoid redundancy and complexity in
individual drivers by allocating session memory in the framework and
providing it to drivers in ::newsession().
Session handles are no longer integers with information encoded in various
high bits. Use of the CRYPTO_SESID2FOO() macros should be replaced with the
appropriate crypto_ses2foo() function on the opaque session handle.
Convert OCF drivers (in particular, cryptosoft, as well as myriad others) to
the opaque handle interface. Discard existing session tracking as much as
possible (quick pass). There may be additional code ripe for deletion.
Convert OCF consumers (ipsec, geom_eli, krb5, cryptodev) to handle-style
interface. The conversion is largely mechnical.
The change is documented in crypto.9.
Inspired by
https://lists.freebsd.org/pipermail/freebsd-arch/2018-January/018835.html .
No objection from: ae (ipsec portion)
Reported by: jhb
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
In integrity mode, a larger logical sector (e.g., 4096 bytes) spans several
physical sectors (e.g., 512 bytes) on the backing device. Due to hash
overhead, a 4096 byte logical sector takes 8.5625 512-byte physical sectors.
This means that only 288 bytes (256 data + 32 hash) of the last 512 byte
sector are used.
The memory allocation used to store the encrypted data to be written to the
physical sectors comes from malloc(9) and does not use M_ZERO.
Previously, nothing initialized the final physical sector backing each
logical sector, aside from the hash + encrypted data portion. So 224 bytes
of kernel heap memory was leaked to every block :-(.
This patch addresses the issue by initializing the trailing portion of the
physical sector in every logical sector to zeros before use. A much simpler
but higher overhead fix would be to tag the entire allocation M_ZERO.
PR: 222077
Reported by: Maxim Khitrov <max AT mxcrypt.com>
Reviewed by: emaste
Security: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D12272
so we cannot access it anymore. Setting an error later lead to memory
corruption.
Assert that crypto_dispatch() was successful. It can fail only if we pass a
bogus crypto request, which is a bug in the program, not a runtime condition.
PR: 199705
Submitted by: luke.tw
Reviewed by: emaste
MFC after: 3 days
for counter mode), and AES-GCM. Both of these modes have been added to
the aesni module.
Included is a set of tests to validate that the software and aesni
module calculate the correct values. These use the NIST KAT test
vectors. To run the test, you will need to install a soon to be
committed port, nist-kat that will install the vectors. Using a port
is necessary as the test vectors are around 25MB.
All the man pages were updated. I have added a new man page, crypto.7,
which includes a description of how to use each mode. All the new modes
and some other AES modes are present. It would be good for someone
else to go through and document the other modes.
A new ioctl was added to support AEAD modes which AES-GCM is one of them.
Without this ioctl, it is not possible to test AEAD modes from userland.
Add a timing safe bcmp for use to compare MACs. Previously we were using
bcmp which could leak timing info and result in the ability to forge
messages.
Add a minor optimization to the aesni module so that single segment
mbufs don't get copied and instead are updated in place. The aesni
module needs to be updated to support blocked IO so segmented mbufs
don't have to be copied.
We require that the IV be specified for all calls for both GCM and ICM.
This is to ensure proper use of these functions.
Obtained from: p4: //depot/projects/opencrypto
Relnotes: yes
Sponsored by: FreeBSD Foundation
Sponsored by: NetGate
driver when it hits a mbuf/iov buffer, it mallocs and copies the data
for processing.. This improves perf by ~8-10% on my machine...
I have thoughts of fixing AES-NI so that it can better handle segmented
buffers, which should help improve IPSEC performance, but that is for
the future...
was not updated to pass CRD_F_KEY_EXPLICIT flag to opencrypto. This resulted in
always using first key.
We need to support providers created with this bug, so set special
G_ELI_FLAG_FIRST_KEY flag for GELI provider in integrity mode with version
smaller than 6 and pass the CRD_F_KEY_EXPLICIT flag to opencrypto only if
G_ELI_FLAG_FIRST_KEY doesn't exist.
Reported by: Anton Yuzhaninov <citrin@citrin.ru>
MFC after: 1 week
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
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.
