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5 Commits

Author SHA1 Message Date
Linus Torvalds 26b265cd29 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
 - Made x86 ablk_helper generic for ARM
 - Phase out chainiv in favour of eseqiv (affects IPsec)
 - Fixed aes-cbc IV corruption on s390
 - Added constant-time crypto_memneq which replaces memcmp
 - Fixed aes-ctr in omap-aes
 - Added OMAP3 ROM RNG support
 - Add PRNG support for MSM SoC's
 - Add and use Job Ring API in caam
 - Misc fixes

[ NOTE! This pull request was sent within the merge window, but Herbert
  has some questionable email sending setup that makes him public enemy
  #1 as far as gmail is concerned.  So most of his emails seem to be
  trapped by gmail as spam, resulting in me not seeing them.  - Linus ]

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (49 commits)
  crypto: s390 - Fix aes-cbc IV corruption
  crypto: omap-aes - Fix CTR mode counter length
  crypto: omap-sham - Add missing modalias
  padata: make the sequence counter an atomic_t
  crypto: caam - Modify the interface layers to use JR API's
  crypto: caam - Add API's to allocate/free Job Rings
  crypto: caam - Add Platform driver for Job Ring
  hwrng: msm - Add PRNG support for MSM SoC's
  ARM: DT: msm: Add Qualcomm's PRNG driver binding document
  crypto: skcipher - Use eseqiv even on UP machines
  crypto: talitos - Simplify key parsing
  crypto: picoxcell - Simplify and harden key parsing
  crypto: ixp4xx - Simplify and harden key parsing
  crypto: authencesn - Simplify key parsing
  crypto: authenc - Export key parsing helper function
  crypto: mv_cesa: remove deprecated IRQF_DISABLED
  hwrng: OMAP3 ROM Random Number Generator support
  crypto: sha256_ssse3 - also test for BMI2
  crypto: mv_cesa - Remove redundant of_match_ptr
  crypto: sahara - Remove redundant of_match_ptr
  ...
2013-11-23 16:18:25 -08:00
Dmitry Kasatkin 3fe78ca2fb keys: change asymmetric keys to use common hash definitions
This patch makes use of the newly defined common hash algorithm info,
replacing, for example, PKEY_HASH with HASH_ALGO.

Changelog:
- Lindent fixes - Mimi

CC: David Howells <dhowells@redhat.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:15:18 -04:00
James Yonan 6bf37e5aa9 crypto: crypto_memneq - add equality testing of memory regions w/o timing leaks
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>
2013-10-07 14:17:06 +08:00
David Howells 0b1568a453 RSA: Fix signature verification for shorter signatures
gpg can produce a signature file where length of signature is less than the
modulus size because the amount of space an MPI takes up is kept as low as
possible by discarding leading zeros.  This regularly happens for several
modules during the build.

Fix it by relaxing check in RSA verification code.

Thanks to Tomas Mraz and Miloslav Trmac for help.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08 13:50:17 +10:30
David Howells 612e0fe999 RSA: Implement signature verification algorithm [PKCS#1 / RFC3447]
Implement RSA public key cryptography [PKCS#1 / RFC3447].  At this time, only
the signature verification algorithm is supported.  This uses the asymmetric
public key subtype to hold its key data.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08 13:50:16 +10:30