Commit Graph

138 Commits

Author SHA1 Message Date
Eric Biggers
231baecdef crypto: clarify name of WEAK_KEY request flag
CRYPTO_TFM_REQ_WEAK_KEY confuses newcomers to the crypto API because it
sounds like it is requesting a weak key.  Actually, it is requesting
that weak keys be forbidden (for algorithms that have the notion of
"weak keys"; currently only DES and XTS do).

Also it is only one letter away from CRYPTO_TFM_RES_WEAK_KEY, with which
it can be easily confused.  (This in fact happened in the UX500 driver,
though just in some debugging messages.)

Therefore, make the intent clear by renaming it to
CRYPTO_TFM_REQ_FORBID_WEAK_KEYS.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-01-25 18:41:52 +08:00
Eric Biggers
bec9ba7f37 crypto: cipher - remove struct cipher_desc
'struct cipher_desc' is unused.  Remove it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-01-11 14:16:55 +08:00
Eric Biggers
c79b411eaa crypto: skcipher - remove remnants of internal IV generators
Remove dead code related to internal IV generators, which are no longer
used since they've been replaced with the "seqiv" and "echainiv"
templates.  The removed code includes:

- The "givcipher" (GIVCIPHER) algorithm type.  No algorithms are
  registered with this type anymore, so it's unneeded.

- The "const char *geniv" member of aead_alg, ablkcipher_alg, and
  blkcipher_alg.  A few algorithms still set this, but it isn't used
  anymore except to show via /proc/crypto and CRYPTO_MSG_GETALG.
  Just hardcode "<default>" or "<none>" in those cases.

- The 'skcipher_givcrypt_request' structure, which is never used.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-23 11:52:45 +08:00
Corentin Labbe
bfad6cb3f8 crypto: api - document missing stats member
This patchs adds missing member of stats documentation.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-23 11:52:44 +08:00
Corentin Labbe
1f6669b971 crypto: user - Add crypto_stats_init
This patch add the crypto_stats_init() function.
This will permit to remove some ifdef from __crypto_register_alg().

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-07 14:15:00 +08:00
Corentin Labbe
44f13133cb crypto: user - rename err_cnt parameter
Since now all crypto stats are on their own structures, it is now
useless to have the algorithm name in the err_cnt member.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-07 14:15:00 +08:00
Corentin Labbe
17c18f9e33 crypto: user - Split stats in multiple structures
Like for userspace, this patch splits stats into multiple structures,
one for each algorithm class.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-07 14:15:00 +08:00
Corentin Labbe
f7d76e05d0 crypto: user - fix use_after_free of struct xxx_request
All crypto_stats functions use the struct xxx_request for feeding stats,
but in some case this structure could already be freed.

For fixing this, the needed parameters (len and alg) will be stored
before the request being executed.
Fixes: cac5818c25 ("crypto: user - Implement a generic crypto statistics")
Reported-by: syzbot <syzbot+6939a606a5305e9e9799@syzkaller.appspotmail.com>

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-07 14:15:00 +08:00
Corentin Labbe
6e8e72cd20 crypto: user - convert all stats from u32 to u64
All the 32-bit fields need to be 64-bit.  In some cases, UINT32_MAX crypto
operations can be done in seconds.

Reported-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-07 14:15:00 +08:00
Corentin Labbe
2ced26078f crypto: user - made crypto_user_stat optional
Even if CRYPTO_STATS is set to n, some part of CRYPTO_STATS are
compiled.
This patch made all part of crypto_user_stat uncompiled in that case.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-07 14:15:00 +08:00
Corentin Labbe
cac5818c25 crypto: user - Implement a generic crypto statistics
This patch implement a generic way to get statistics about all crypto
usages.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-28 12:46:25 +08:00
Matthew Garrett
e2861fa716 evm: Don't deadlock if a crypto algorithm is unavailable
When EVM attempts to appraise a file signed with a crypto algorithm the
kernel doesn't have support for, it will cause the kernel to trigger a
module load. If the EVM policy includes appraisal of kernel modules this
will in turn call back into EVM - since EVM is holding a lock until the
crypto initialisation is complete, this triggers a deadlock. Add a
CRYPTO_NOLOAD flag and skip module loading if it's set, and add that flag
in the EVM case in order to fail gracefully with an error message
instead of deadlocking.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-07-18 07:27:22 -04:00
Gary R Hook
0063ec4459 crypto: doc - Document remaining members in struct crypto_alg
Add missing comments for union members ablkcipher, blkcipher,
cipher, and compress. This silences complaints when building
the htmldocs.

Fixes: 0d7f488f03 (crypto: doc - cipher data structures)
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-03-23 23:48:43 +08:00
Eric Biggers
9fa68f6200 crypto: hash - prevent using keyed hashes without setting key
Currently, almost none of the keyed hash algorithms check whether a key
has been set before proceeding.  Some algorithms are okay with this and
will effectively just use a key of all 0's or some other bogus default.
However, others will severely break, as demonstrated using
"hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash
via a (potentially exploitable) stack buffer overflow.

A while ago, this problem was solved for AF_ALG by pairing each hash
transform with a 'has_key' bool.  However, there are still other places
in the kernel where userspace can specify an arbitrary hash algorithm by
name, and the kernel uses it as unkeyed hash without checking whether it
is really unkeyed.  Examples of this include:

    - KEYCTL_DH_COMPUTE, via the KDF extension
    - dm-verity
    - dm-crypt, via the ESSIV support
    - dm-integrity, via the "internal hash" mode with no key given
    - drbd (Distributed Replicated Block Device)

This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no
privileges to call.

Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the
->crt_flags of each hash transform that indicates whether the transform
still needs to be keyed or not.  Then, make the hash init, import, and
digest functions return -ENOKEY if the key is still needed.

The new flag also replaces the 'has_key' bool which algif_hash was
previously using, thereby simplifying the algif_hash implementation.

Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-12 23:03:37 +11:00
Eric Biggers
a208fa8f33 crypto: hash - annotate algorithms taking optional key
We need to consistently enforce that keyed hashes cannot be used without
setting the key.  To do this we need a reliable way to determine whether
a given hash algorithm is keyed or not.  AF_ALG currently does this by
checking for the presence of a ->setkey() method.  However, this is
actually slightly broken because the CRC-32 algorithms implement
->setkey() but can also be used without a key.  (The CRC-32 "key" is not
actually a cryptographic key but rather represents the initial state.
If not overridden, then a default initial state is used.)

Prepare to fix this by introducing a flag CRYPTO_ALG_OPTIONAL_KEY which
indicates that the algorithm has a ->setkey() method, but it is not
required to be called.  Then set it on all the CRC-32 algorithms.

The same also applies to the Adler-32 implementation in Lustre.

Also, the cryptd and mcryptd templates have to pass through the flag
from their underlying algorithm.

Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-12 23:03:35 +11:00
Eric Biggers
ce8614a312 crypto: algapi - convert cra_refcnt to refcount_t
Reference counters should use refcount_t rather than atomic_t, since the
refcount_t implementation can prevent overflows, reducing the
exploitability of reference leak bugs.  crypto_alg.cra_refcount is a
reference counter with the usual semantics, so switch it over to
refcount_t.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-05 18:43:09 +11:00
Gilad Ben-Yossef
ada69a1639 crypto: introduce crypto wait for async op
Invoking a possibly async. crypto op and waiting for completion
while correctly handling backlog processing is a common task
in the crypto API implementation and outside users of it.

This patch adds a generic implementation for doing so in
preparation for using it across the board instead of hand
rolled versions.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
CC: Eric Biggers <ebiggers3@gmail.com>
CC: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-03 22:11:18 +08:00
Herbert Xu
f437a3f477 crypto: api - Extend algorithm name limit to 128 bytes
With the new explicit IV generators, we may now exceed the 64-byte
length limit on the algorithm name, e.g., with

	echainiv(authencesn(hmac(sha256-generic),cbc(des3_ede-generic)))

This patch extends the length limit to 128 bytes.

Reported-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
2017-04-10 19:17:27 +08:00
Linus Torvalds
0aaf2146ec Merge tag 'docs-4.10-2' of git://git.lwn.net/linux
Pull more documentation updates from Jonathan Corbet:
 "This converts the crypto DocBook to Sphinx"

* tag 'docs-4.10-2' of git://git.lwn.net/linux:
  crypto: doc - optimize compilation
  crypto: doc - clarify AEAD memory structure
  crypto: doc - remove crypto_alloc_ablkcipher
  crypto: doc - add KPP documentation
  crypto: doc - fix separation of cipher / req API
  crypto: doc - fix source comments for Sphinx
  crypto: doc - remove crypto API DocBook
  crypto: doc - convert crypto API documentation to Sphinx
2016-12-17 16:00:34 -08:00
Stephan Mueller
0184cfe72d crypto: doc - fix source comments for Sphinx
Update comments to avoid any complaints from Sphinx during compilation.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-12-13 16:38:05 -07:00
Baruch Siach
864e0981fd crypto: api - fix comment typo
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-12-01 21:06:30 +08:00
Giovanni Cabiddu
1ab53a77b7 crypto: acomp - add driver-side scomp interface
Add a synchronous back-end (scomp) to acomp. This allows to easily
expose the already present compression algorithms in LKCF via acomp.

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-10-25 11:08:31 +08:00
Giovanni Cabiddu
2ebda74fd6 crypto: acomp - add asynchronous compression api
Add acomp, an asynchronous compression api that uses scatterlist
buffers.

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-10-25 11:08:30 +08:00
Herbert Xu
3a01d0ee2b crypto: skcipher - Remove top-level givcipher interface
This patch removes the old crypto_grab_skcipher helper and replaces
it with crypto_grab_skcipher2.

As this is the final entry point into givcipher this patch also
removes all traces of the top-level givcipher interface, including
all implicit IV generators such as chainiv.

The bottom-level givcipher interface remains until the drivers
using it are converted.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-18 17:35:46 +08:00
Herbert Xu
4e6c3df4d7 crypto: skcipher - Add low-level skcipher interface
This patch allows skcipher algorithms and instances to be created
and registered with the crypto API.  They are accessible through
the top-level skcipher interface, along with ablkcipher/blkcipher
algorithms and instances.

This patch also introduces a new parameter called chunk size
which is meant for ciphers such as CTR and CTS which ostensibly
can handle arbitrary lengths, but still behave like block ciphers
in that you can only process a partial block at the very end.

For these ciphers the block size will continue to be set to 1
as it is now while the chunk size will be set to the underlying
block size.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-18 17:35:36 +08:00