Commit Graph

37 Commits

Author SHA1 Message Date
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 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
Kees Cook b68a7ec1e9 crypto: hash - Remove VLA usage
In the quest to remove all stack VLA usage from the kernel[1], this
removes the VLAs in SHASH_DESC_ON_STACK (via crypto_shash_descsize())
by using the maximum allowable size (which is now more clearly captured
in a macro), along with a few other cases. Similar limits are turned into
macros as well.

A review of existing sizes shows that SHA512_DIGEST_SIZE (64) is the
largest digest size and that sizeof(struct sha3_state) (360) is the
largest descriptor size. The corresponding maximums are reduced.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-04 11:35:03 +08:00
Kamil Konieczny 3d053d53fc crypto: hash - Prevent use of req->result in ahash update
Prevent improper use of req->result field in ahash update, init, export and
import functions in drivers code. A driver should use ahash request context
if it needs to save internal state.

Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-03-16 23:35:52 +08:00
tcharding b40fa82cd6 crypto: doc - clear htmldocs build warnings for crypto/hash
SPHINX build emits multiple warnings of kind:

	warning: duplicate section name 'Note'

(when building kernel via make target 'htmldocs')

This is caused by repeated use of comments of form:

	* Note: soau soaeusoa uoe

We can change the format without loss of clarity and clear the build
warnings.

Add '**[mandatory]**' or '**[optional]**' as kernel-doc field element
description prefix

This renders in HTML as (prefixes in bold)

final
    [mandatory] Retrieve result from the driver. This function finalizes the
    transformation and retrieves the resulting hash from the driver and
    pushes it back to upper layers. No data processing happens at this
    point unless hardware requires it to finish the transformation (then
    the data buffered by the device driver is processed).

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-12 23:03:44 +11:00
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
Kamil Konieczny 560b1a82ee crypto: doc - clarify return values for async hash methods
* fix documentation of return values for crypto_ahash_init(),
  crypto_ahash_finup(), crypto_ahash_final(),
  crypto_ahash_digest() and crypto_ahash_update()

Also while at it:

* add notes for device driver developers in struct ahash_alg
  description

* fix description of @final method in struct ahash_alg

* fix typo in crypto_ahash_finup() description

Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-09-22 17:43:03 +08:00
Rabin Vincent 379d972b81 crypto: doc - Fix hash export state information
The documentation states that crypto_ahash_reqsize() provides the size
of the state structure used by crypto_ahash_export().  But it's actually
crypto_ahash_statesize() which provides this size.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-02-03 18:16:11 +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
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 d12481bc58 crypto: hash - Add helpers to return alg and driver names
This patch adds helpers to retrieve the alg name and driver name
of crypto_shash and crypto_ahash objects.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-06 15:33:13 +08:00
Herbert Xu 8d18e34c1f crypto: hash - Add crypto_has_ahash helper
This patch adds the helper crypto_has_ahash which should replace
crypto_has_hash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-25 22:42:13 +08:00
Herbert Xu e67ffe0af4 crypto: hash - Add helpers to zero stack request/descriptor
As the size of an ahash_request or shash_desc is variable, it's
awkward to zero them explicitly.  This patch adds helpers to do
that which should be used when they are created on the stack.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-25 22:42:11 +08:00
Herbert Xu a5596d6332 crypto: hash - Add crypto_ahash_has_setkey
This patch adds a way for ahash users to determine whether a key
is required by a crypto_ahash transform.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-18 18:16:11 +08:00
Herbert Xu 524e56c31a crypto: ahash - Add crypto_ahash_blocksize
This patch adds the missing helper crypto_ahash_blocksize which
returns the block size of an ahash algorithm.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-10-20 22:10:48 +08:00
Herbert Xu d4421c54c4 crypto: hash - Add AHASH_REQUEST_ON_STACK
This patch adds the helper AHASH_REQUEST_ON_STACK for those users
of ahash that are synchronous only.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-08-21 22:21:20 +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
Stephan Mueller 52744af3af crypto: doc - document uncovered member variables
Fix documentation typo for shash_alg->descsize.

Add documentation for initially uncovered member variables.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-11-17 22:53:48 +08:00
Stephan Mueller 968ab29107 crypto: doc - SHASH API documentation
The API function calls exported by the kernel crypto API for SHASHes
to be used by consumers are documented.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-11-13 22:31:40 +08:00
Stephan Mueller 90240ffb12 crypto: doc - AHASH API documentation
The API function calls exported by the kernel crypto API for AHASHes
to be used by consumers are documented.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-11-13 22:31:39 +08:00
Stephan Mueller 5d8c723f61 crypto: doc - hash data structures
The hash data structures needed to be filled in by cipher developers are
documented.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-11-13 22:31:39 +08:00
Behan Webster a0a77af141 crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code
Add a macro which replaces the use of a Variable Length Array In Struct (VLAIS)
with a C99 compliant equivalent. This macro instead allocates the appropriate
amount of memory using an char array.

The new code can be compiled with both gcc and clang.

struct shash_desc contains a flexible array member member ctx declared with
CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
of the array declared after struct shash_desc with long long.

No trailing padding is required because it is not a struct type that can
be used in an array.

The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
as would be the case for a struct containing a member with
CRYPTO_MINALIGN_ATTR.

If you want to get to the ctx at the end of the shash_desc as before you can do
so using shash_desc_ctx(shash)

Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michał Mirosław <mirqus@gmail.com>
2014-10-14 10:51:22 +02:00
Mark Rustad 3e3dc25fe7 crypto: Resolve shadow warnings
Change formal parameters to not clash with global names to
eliminate many W=2 warnings.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-08-01 22:35:55 +08:00
Herbert Xu fa64966473 crypto: shash - Fix digest size offset
When an shash algorithm is exported as ahash, ahash will access
its digest size through hash_alg_common.  That's why the shash
layout needs to match hash_alg_common.  This wasn't the case
because the alignment weren't identical.

This patch fixes the problem.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-15 21:16:05 +08:00
Herbert Xu 66f6ce5e52 crypto: ahash - Add unaligned handling and default operations
This patch exports the finup operation where available and adds
a default finup operation for ahash.  The operations final, finup
and digest also will now deal with unaligned result pointers by
copying it.  Finally export/import operations are will now be
exported too.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-15 12:40:40 +08:00
Herbert Xu 500b3e3c3d crypto: ahash - Remove old_ahash_alg
Now that all ahash implementations have been converted to the new
ahash type, we can remove old_ahash_alg and its associated support.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14 20:29:57 +08:00
Herbert Xu 88056ec346 crypto: ahash - Convert to new style algorithms
This patch converts crypto_ahash to the new style.  The old ahash
algorithm type is retained until the existing ahash implementations
are also converted.  All ahash users will automatically get the
new crypto_ahash type.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14 15:54:07 +08:00
Herbert Xu 113adefc73 crypto: shash - Make descsize a run-time attribute
This patch changes descsize to a run-time attribute so that
implementations can change it in their init functions.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14 12:58:00 +08:00
Herbert Xu aef73cfcb9 crypto: async - Use kzfree for requests
This patch changes the kfree call to kzfree for async requests.
As the request may contain sensitive data it needs to be zeroed
before it can be reallocated by others.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-12 10:46:03 +08:00
Herbert Xu 99d27e1c59 crypto: shash - Export/import hash state only
This patch replaces the full descriptor export with an export of
the partial hash state.  This allows the use of a consistent export
format across all implementations of a given algorithm.

This is useful because a number of cases require the use of the
partial hash state, e.g., PadLock can use the SHA1 hash state
to get around the fact that it can only hash contiguous data
chunks.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-11 18:23:32 +08:00
Herbert Xu 9749598633 crypto: shash - Add crypto_shash_blocksize
This function is needed by algorithms that don't know their own
block size, e.g., in s390 where the code is common between multiple
versions of SHA.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-18 16:48:06 +08:00
Herbert Xu 412e87ae5d crypto: shash - Fix tfm destruction
We were freeing an offset into the slab object instead of the
start.  This patch fixes it by calling crypto_destroy_tfm which
allows the correct address to be given.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-05 16:51:25 +11:00
Herbert Xu dec8b78606 crypto: hash - Add import/export interface
It is often useful to save the partial state of a hash function
so that it can be used as a base for two or more computations.

The most prominent example is HMAC where all hashes start from
a base determined by the key.  Having an import/export interface
means that we only have to compute that base once rather than
for each message.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25 11:01:30 +11:00
Herbert Xu 7b5a080b3c crypto: hash - Add shash interface
The shash interface replaces the current synchronous hash interface.
It improves over hash in two ways.  Firstly shash is reentrant,
meaning that the same tfm may be used by two threads simultaneously
as all hashing state is stored in a local descriptor.

The other enhancement is that shash no longer takes scatter list
entries.  This is because shash is specifically designed for
synchronous algorithms and as such scatter lists are unnecessary.

All existing hash users will be converted to shash once the
algorithms have been completely converted.

There is also a new finup function that combines update with final.
This will be extended to ahash once the algorithm conversion is
done.

This is also the first time that an algorithm type has their own
registration function.  Existing algorithm types will be converted
to this way in due course.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25 11:01:26 +11:00
Herbert Xu 318e531392 crypto: hash - Add missing top-level functions
The top-level functions init/update/final were missing for ahash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-08-13 20:08:44 +10:00
Herbert Xu 18e33e6d5c crypto: hash - Move ahash functions into crypto/hash.h
All new crypto interfaces should go into individual files as much
as possible in order to ensure that crypto.h does not collapse under
its own weight.

This patch moves the ahash code into crypto/hash.h and crypto/internal/hash.h
respectively.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-07-10 20:35:18 +08:00