In the quest to remove all stack VLA usage from the kernel[1], this
replaces struct crypto_skcipher and SKCIPHER_REQUEST_ON_STACK() usage
with struct crypto_sync_skcipher and SYNC_SKCIPHER_REQUEST_ON_STACK(),
which uses a fixed stack size.
[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>
In crypto_authenc_esn_setkey we save pointers to the authenc keys
in a local variable of type struct crypto_authenc_keys and we don't
zeroize it after use. Fix this and don't leak pointers to the
authenc keys.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since commit 499a66e6b6 ("crypto: null - Remove default null
blkcipher"), crypto_get_default_null_skcipher2() and
crypto_put_default_null_skcipher2() are the same as their non-2
equivalents. So switch callers of the "2" versions over to the original
versions and remove the "2" versions.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When authencesn is used together with digest_null a crash will
occur on the decrypt path. This is because normally we perform
a special setup to preserve the ESN, but this is skipped if there
is no authentication. However, on the post-authentication path
it always expects the preservation to be in place, thus causing
a crash when digest_null is used.
This patch fixes this by also skipping the post-processing when
there is no authentication.
Fixes: 104880a6b4 ("crypto: authencesn - Convert to new AEAD...")
Cc: <stable@vger.kernel.org>
Reported-by: Jan Tluka <jtluka@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since commit 3a01d0ee2b ("crypto: skcipher - Remove top-level
givcipher interface"), crypto_spawn_skcipher2() and
crypto_spawn_skcipher() are equivalent. So switch callers of
crypto_spawn_skcipher2() to crypto_spawn_skcipher() and remove it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since commit 3a01d0ee2b ("crypto: skcipher - Remove top-level
givcipher interface"), crypto_grab_skcipher2() and
crypto_grab_skcipher() are equivalent. So switch callers of
crypto_grab_skcipher2() to crypto_grab_skcipher() and remove it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch converts authencesn to use the new skcipher interface as
opposed to ablkcipher.
It also fixes a little bug where if a sync version of authencesn
is requested we may still end up using an async ahash. This should
have no effect as none of the authencesn users can request for a
sync authencesn.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As it is, if you get an async ahash with a sync skcipher you'll
end up with a sync authenc, which is wrong.
This patch fixes it by considering the ASYNC bit from ahash as
well.
It also fixes a little bug where if a sync version of authenc
is requested we may still end up using an async ahash.
Neither of them should have any effect as none of the authenc
users can request for a sync authenc.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The ESP code has been updated to generate a completely linear
AD SG list. This unfortunately broke authencesn which expects
the AD to be divided into at least three parts.
This patch fixes it to cope with the new format. Later we will
fix it properly to accept arbitrary input and not rely on the
input being linear as part of the AEAD conversion.
Fixes: 7021b2e1cd ("esp4: Switch to new AEAD interface")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch uses the crypto_aead_set_reqsize helper to avoid directly
touching the internals of aead.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This adds the module loading prefix "crypto-" to the template lookup
as well.
For example, attempting to load 'vfat(blowfish)' via AF_ALG now correctly
includes the "crypto-" prefix at every level, correctly rejecting "vfat":
net-pf-38
algif-hash
crypto-vfat(blowfish)
crypto-vfat(blowfish)-all
crypto-vfat
Reported-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use the common helper function crypto_authenc_extractkeys() for key
parsing.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Mathias Krause <mathias.krause@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When comparing MAC hashes, AEAD authentication tags, or other hash
values in the context of authentication or integrity checking, it
is important not to leak timing information to a potential attacker,
i.e. when communication happens over a network.
Bytewise memory comparisons (such as memcmp) are usually optimized so
that they return a nonzero value as soon as a mismatch is found. E.g,
on x86_64/i5 for 512 bytes this can be ~50 cyc for a full mismatch
and up to ~850 cyc for a full match (cold). This early-return behavior
can leak timing information as a side channel, allowing an attacker to
iteratively guess the correct result.
This patch adds a new method crypto_memneq ("memory not equal to each
other") to the crypto API that compares memory areas of the same length
in roughly "constant time" (cache misses could change the timing, but
since they don't reveal information about the content of the strings
being compared, they are effectively benign). Iow, best and worst case
behaviour take the same amount of time to complete (in contrast to
memcmp).
Note that crypto_memneq (unlike memcmp) can only be used to test for
equality or inequality, NOT for lexicographical order. This, however,
is not an issue for its use-cases within the crypto API.
We tried to locate all of the places in the crypto API where memcmp was
being used for authentication or integrity checking, and convert them
over to crypto_memneq.
crypto_memneq is declared noinline, placed in its own source file,
and compiled with optimizations that might increase code size disabled
("Os") because a smart compiler (or LTO) might notice that the return
value is always compared against zero/nonzero, and might then
reintroduce the same early-return optimization that we are trying to
avoid.
Using #pragma or __attribute__ optimization annotations of the code
for disabling optimization was avoided as it seems to be considered
broken or unmaintained for long time in GCC [1]. Therefore, we work
around that by specifying the compile flag for memneq.o directly in
the Makefile. We found that this seems to be most appropriate.
As we use ("Os"), this patch also provides a loop-free "fast-path" for
frequently used 16 byte digests. Similarly to kernel library string
functions, leave an option for future even further optimized architecture
specific assembler implementations.
This was a joint work of James Yonan and Daniel Borkmann. Also thanks
for feedback from Florian Weimer on this and earlier proposals [2].
[1] http://gcc.gnu.org/ml/gcc/2012-07/msg00211.html
[2] https://lkml.org/lkml/2013/2/10/131
Signed-off-by: James Yonan <james@openvpn.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Replace PTR_ERR followed by ERR_PTR by ERR_CAST, to be more concise.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression err,x;
@@
- err = PTR_ERR(x);
if (IS_ERR(x))
- return ERR_PTR(err);
+ return ERR_CAST(x);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
ESP with separate encryption/authentication algorithms needs a special
treatment for the associated data. This patch add a new algorithm that
handles esp with extended sequence numbers.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Harsh Jain
Kees Cook
Tudor-Dan Ambarus
Eric Biggers
Herbert Xu
Mathias Krause
James Yonan
Julia Lawall
Steffen Klassert