Commit Graph

126 Commits

Author SHA1 Message Date
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
Salvatore Benedetto
4e5f2c4007 crypto: kpp - Key-agreement Protocol Primitives API (KPP)
Add key-agreement protocol primitives (kpp) API which allows to
implement primitives required by protocols such as DH and ECDH.
The API is composed mainly by the following functions
 * set_secret() - It allows the user to set his secret, also
   referred to as his private key, along with the parameters
   known to both parties involved in the key-agreement session.
 * generate_public_key() - It generates the public key to be sent to
   the other counterpart involved in the key-agreement session. The
   function has to be called after set_params() and set_secret()
 * generate_secret() - It generates the shared secret for the session

Other functions such as init() and exit() are provided for allowing
cryptographic hardware to be inizialized properly before use

Signed-off-by: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-06-23 18:29:56 +08:00
Giovanni Cabiddu
63044c4fd4 crypto: hash - shrink hash down to two types
Move hash to 0xe to free up the space for acomp/scomp

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-06-07 18:41:54 +08:00
Eric Biggers
6eae29e7e7 crypto: doc - document correct return value for request allocation
Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-15 22:35:44 +08:00
Herbert Xu
8965450987 crypto: hash - Remove crypto_hash interface
This patch removes all traces of the crypto_hash interface, now
that everyone has switched over to shash or ahash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-06 15:33:20 +08:00
Joonsoo Kim
110492183c crypto: compress - remove unused pcomp interface
It is unused now, so remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-27 20:36:24 +08:00
Herbert Xu
5e4b8c1fcc crypto: aead - Remove CRYPTO_ALG_AEAD_NEW flag
This patch removes the CRYPTO_ALG_AEAD_NEW flag now that everyone
has been converted.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-08-17 16:53:53 +08:00
Herbert Xu
b0d955ba46 crypto: aead - Remove old AEAD interfaces
Now that the AEAD conversion is complete we can rip out the old
AEAD interafce and associated code.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-08-17 16:53:50 +08:00
Herbert Xu
3e90950d36 crypto: algif_aead - Temporarily disable all AEAD algorithms
As the AEAD conversion is still ongoing, we do not yet wish to
export legacy AEAD implementations to user-space, as their calling
convention will change.

This patch actually disables all AEAD algorithms because some of
them (e.g., cryptd) will need to be modified to propagate this flag.

Subsequent patches will reenable them on an individual basis.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-22 15:49:30 +08:00
Herbert Xu
edf18b9108 crypto: api - Add CRYPTO_MINALIGN_ATTR to struct crypto_alg
The struct crypto_alg is embedded into various type-specific structs
such as aead_alg.  This is then used as part of instances such as
struct aead_instance.  It is also embedded into the generic struct
crypto_instance.  In order to ensure that struct aead_instance can
be converted to struct crypto_instance when necessary, we need to
ensure that crypto_alg is aligned properly.

This patch adds an alignment attribute to struct crypto_alg to
ensure this.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-19 14:16:28 +08:00
Tadeusz Struk
3c339ab83f crypto: akcipher - add PKE API
Add Public Key Encryption API.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>

Made CRYPTO_AKCIPHER invisible like other type config options.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-17 17:03:14 +08:00
Masanari Iida
12f7c14aa6 crypto: doc - Fix typo in crypto-API.xml
This patch fix some typos found in crypto-API.xml.
It is because the file is generated from comments in sources,
so I had to fix typo in sources.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-04 15:05:08 +08:00
Herbert Xu
2d0f230fe0 crypto: aead - Rename aead_alg to old_aead_alg
This patch is the first step in the introduction of a new AEAD
alg type.  Unlike normal conversions this patch only renames the
existing aead_alg structure because there are external references
to it.

Those references will be removed after this patch.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-22 11:25:51 +08:00