Add support for generating ecc private keys.
Generation of ecc private keys is helpful in a user-space to kernel
ecdh offload because the keys are not revealed to user-space. Private
key generation is also helpful to implement forward secrecy.
If the user provides a NULL ecc private key, the kernel will generate it
and further use it for ecdh.
Move ecdh's object files below drbg's. drbg must be present in the kernel
at the time of calling.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
An ancient gcc bug (first reported in 2003) has apparently resurfaced
on MIPS, where kernelci.org reports an overly large stack frame in the
whirlpool hash algorithm:
crypto/wp512.c:987:1: warning: the frame size of 1112 bytes is larger than 1024 bytes [-Wframe-larger-than=]
With some testing in different configurations, I'm seeing large
variations in stack frames size up to 1500 bytes for what should have
around 300 bytes at most. I also checked the reference implementation,
which is essentially the same code but also comes with some test and
benchmarking infrastructure.
It seems that recent compiler versions on at least arm, arm64 and powerpc
have a partial fix for this problem, but enabling "-fsched-pressure", but
even with that fix they suffer from the issue to a certain degree. Some
testing on arm64 shows that the time needed to hash a given amount of
data is roughly proportional to the stack frame size here, which makes
sense given that the wp512 implementation is doing lots of loads for
table lookups, and the problem with the overly large stack is a result
of doing a lot more loads and stores for spilled registers (as seen from
inspecting the object code).
Disabling -fschedule-insns consistently fixes the problem for wp512,
in my collection of cross-compilers, the results are consistently better
or identical when comparing the stack sizes in this function, though
some architectures (notable x86) have schedule-insns disabled by
default.
The four columns are:
default: -O2
press: -O2 -fsched-pressure
nopress: -O2 -fschedule-insns -fno-sched-pressure
nosched: -O2 -no-schedule-insns (disables sched-pressure)
default press nopress nosched
alpha-linux-gcc-4.9.3 1136 848 1136 176
am33_2.0-linux-gcc-4.9.3 2100 2076 2100 2104
arm-linux-gnueabi-gcc-4.9.3 848 848 1048 352
cris-linux-gcc-4.9.3 272 272 272 272
frv-linux-gcc-4.9.3 1128 1000 1128 280
hppa64-linux-gcc-4.9.3 1128 336 1128 184
hppa-linux-gcc-4.9.3 644 308 644 276
i386-linux-gcc-4.9.3 352 352 352 352
m32r-linux-gcc-4.9.3 720 656 720 268
microblaze-linux-gcc-4.9.3 1108 604 1108 256
mips64-linux-gcc-4.9.3 1328 592 1328 208
mips-linux-gcc-4.9.3 1096 624 1096 240
powerpc64-linux-gcc-4.9.3 1088 432 1088 160
powerpc-linux-gcc-4.9.3 1080 584 1080 224
s390-linux-gcc-4.9.3 456 456 624 360
sh3-linux-gcc-4.9.3 292 292 292 292
sparc64-linux-gcc-4.9.3 992 240 992 208
sparc-linux-gcc-4.9.3 680 592 680 312
x86_64-linux-gcc-4.9.3 224 240 272 224
xtensa-linux-gcc-4.9.3 1152 704 1152 304
aarch64-linux-gcc-7.0.0 224 224 1104 208
arm-linux-gnueabi-gcc-7.0.1 824 824 1048 352
mips-linux-gcc-7.0.0 1120 648 1120 272
x86_64-linux-gcc-7.0.1 240 240 304 240
arm-linux-gnueabi-gcc-4.4.7 840 392
arm-linux-gnueabi-gcc-4.5.4 784 728 784 320
arm-linux-gnueabi-gcc-4.6.4 736 728 736 304
arm-linux-gnueabi-gcc-4.7.4 944 784 944 352
arm-linux-gnueabi-gcc-4.8.5 464 464 760 352
arm-linux-gnueabi-gcc-4.9.3 848 848 1048 352
arm-linux-gnueabi-gcc-5.3.1 824 824 1064 336
arm-linux-gnueabi-gcc-6.1.1 808 808 1056 344
arm-linux-gnueabi-gcc-7.0.1 824 824 1048 352
Trying the same test for serpent-generic, the picture is a bit different,
and while -fno-schedule-insns is generally better here than the default,
-fsched-pressure wins overall, so I picked that instead.
default press nopress nosched
alpha-linux-gcc-4.9.3 1392 864 1392 960
am33_2.0-linux-gcc-4.9.3 536 524 536 528
arm-linux-gnueabi-gcc-4.9.3 552 552 776 536
cris-linux-gcc-4.9.3 528 528 528 528
frv-linux-gcc-4.9.3 536 400 536 504
hppa64-linux-gcc-4.9.3 524 208 524 480
hppa-linux-gcc-4.9.3 768 472 768 508
i386-linux-gcc-4.9.3 564 564 564 564
m32r-linux-gcc-4.9.3 712 576 712 532
microblaze-linux-gcc-4.9.3 724 392 724 512
mips64-linux-gcc-4.9.3 720 384 720 496
mips-linux-gcc-4.9.3 728 384 728 496
powerpc64-linux-gcc-4.9.3 704 304 704 480
powerpc-linux-gcc-4.9.3 704 296 704 480
s390-linux-gcc-4.9.3 560 560 592 536
sh3-linux-gcc-4.9.3 540 540 540 540
sparc64-linux-gcc-4.9.3 544 352 544 496
sparc-linux-gcc-4.9.3 544 344 544 496
x86_64-linux-gcc-4.9.3 528 536 576 528
xtensa-linux-gcc-4.9.3 752 544 752 544
aarch64-linux-gcc-7.0.0 432 432 656 480
arm-linux-gnueabi-gcc-7.0.1 616 616 808 536
mips-linux-gcc-7.0.0 720 464 720 488
x86_64-linux-gcc-7.0.1 536 528 600 536
arm-linux-gnueabi-gcc-4.4.7 592 440
arm-linux-gnueabi-gcc-4.5.4 776 448 776 544
arm-linux-gnueabi-gcc-4.6.4 776 448 776 544
arm-linux-gnueabi-gcc-4.7.4 768 448 768 544
arm-linux-gnueabi-gcc-4.8.5 488 488 776 544
arm-linux-gnueabi-gcc-4.9.3 552 552 776 536
arm-linux-gnueabi-gcc-5.3.1 552 552 776 536
arm-linux-gnueabi-gcc-6.1.1 560 560 776 536
arm-linux-gnueabi-gcc-7.0.1 616 616 808 536
I did not do any runtime tests with serpent, so it is possible that stack
frame size does not directly correlate with runtime performance here and
it actually makes things worse, but it's more likely to help here, and
the reduced stack frame size is probably enough reason to apply the patch,
especially given that the crypto code is often used in deep call chains.
Link: https://kernelci.org/build/id/58797d7559b5149efdf6c3a9/logs/
Link: http://www.larc.usp.br/~pbarreto/WhirlpoolPage.html
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79149
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Lookup table based AES is sensitive to timing attacks, which is due to
the fact that such table lookups are data dependent, and the fact that
8 KB worth of tables covers a significant number of cachelines on any
architecture, resulting in an exploitable correlation between the key
and the processing time for known plaintexts.
For network facing algorithms such as CTR, CCM or GCM, this presents a
security risk, which is why arch specific AES ports are typically time
invariant, either through the use of special instructions, or by using
SIMD algorithms that don't rely on table lookups.
For generic code, this is difficult to achieve without losing too much
performance, but we can improve the situation significantly by switching
to an implementation that only needs 256 bytes of table data (the actual
S-box itself), which can be prefetched at the start of each block to
eliminate data dependent latencies.
This code encrypts at ~25 cycles per byte on ARM Cortex-A57 (while the
ordinary generic AES driver manages 18 cycles per byte on this
hardware). Decryption is substantially slower.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Both asn1 headers are included by rsa_helper.c, so rsa_helper.o
should explicitly depend on them.
Signed-off-by: David Michael <david.michael@coreos.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the simd skcipher helper which is meant to be
a replacement for ablk helper. It replaces the underlying blkcipher
interface with skcipher, and also presents the top-level algorithm
as an skcipher.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix dependency between acomp and scomp that appears when acomp is
built as module
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
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>
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>
* Implement ECDH under kpp API
* Provide ECC software support for curve P-192 and
P-256.
* Add kpp test for ECDH with data generated by OpenSSL
Signed-off-by: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* Implement MPI based Diffie-Hellman under kpp API
* Test provided uses data generad by OpenSSL
Signed-off-by: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
This patch adds the implementation of SHA3 algorithm
in software and it's based on original implementation
pushed in patch https://lwn.net/Articles/518415/ with
additional changes to match the padding rules specified
in SHA-3 specification.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now block cipher engines need to implement and maintain their own queue/thread
for processing requests, moreover currently helpers provided for only the queue
itself (in crypto_enqueue_request() and crypto_dequeue_request()) but they
don't help with the mechanics of driving the hardware (things like running the
request immediately, DMA map it or providing a thread to process the queue in)
even though a lot of that code really shouldn't vary that much from device to
device.
Thus this patch provides a mechanism for pushing requests to the hardware
as it becomes free that drivers could use. And this framework is patterned
on the SPI code and has worked out well there.
(https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/
drivers/spi/spi.c?id=ffbbdd21329f3e15eeca6df2d4bc11c04d9d91c0)
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The generic crc32 implementation is currently called crc32. This
is a problem because it clashes with the lib implementation of crc32.
This patch renames the crypto crc32 to crc32_generic so that it is
consistent with crc32c. An alias for the driver is also added.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds PKCS#1 v1.5 standard RSA padding as a separate template.
This way an RSA cipher with padding can be obtained by instantiating
"pkcs1pad(rsa)". The reason for adding this is that RSA is almost
never used without this padding (or OAEP) so it will be needed for
either certificate work in the kernel or the userspace, and I also hear
that it is likely implemented by hardware RSA in which case hardware
implementations of the whole of pkcs1pad(rsa) can be provided.
Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Hook keywrap source code into Kconfig and Makefile
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Setkey function has been split into set_priv_key and set_pub_key.
Akcipher requests takes sgl for src and dst instead of void *.
Users of the API i.e. two existing RSA implementation and
test mgr code have been updated accordingly.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch introduces the crypto skcipher interface which aims
to replace both blkcipher and ablkcipher.
It's very similar to the existing ablkcipher interface. The
main difference is the removal of the givcrypt interface. In
order to make the transition easier for blkcipher users, there
is a helper SKCIPHER_REQUEST_ON_STACK which can be used to place
a request on the stack for synchronous transforms.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The Kconfig option NULL2 has been added as CRYPTO_MANAGER now
depends indirectly on NULL2. However, the Makefile was not updated
to use the new option, resulting in potential build failures when
only NULL2 is enabled.
Fixes: 149a39717d ("crypto: aead - Add type-safe geniv init/exit helpers")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The core of the Jitter RNG is intended to be compiled with -O0. To
ensure that the Jitter RNG can be compiled on all architectures,
separate out the RNG core into a stand-alone C file that can be compiled
with -O0 which does not depend on any kernel include file.
As no kernel includes can be used in the C file implementing the core
RNG, any dependencies on kernel code must be extracted.
A second file provides the link to the kernel and the kernel crypto API
that can be compiled with the regular compile options of the kernel.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a new rsa generic SW implementation.
This implements only cryptographic primitives.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Added select on ASN1.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
Replace the global -O0 compiler flag from the Makefile with GCC
pragmas to mark only the functions required to be compiled without
optimizations.
This patch also adds a comment describing the rationale for the
functions chosen to be compiled without optimizations.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This AEAD uses a chacha20 ablkcipher and a poly1305 ahash to construct the
ChaCha20-Poly1305 AEAD as defined in RFC7539. It supports both synchronous and
asynchronous operations, even if we currently have no async chacha20 or poly1305
drivers.
Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Poly1305 is a fast message authenticator designed by Daniel J. Bernstein.
It is further defined in RFC7539 as a building block for the ChaCha20-Poly1305
AEAD for use in IETF protocols.
This is a portable C implementation of the algorithm without architecture
specific optimizations, based on public domain code by Daniel J. Bernstein and
Andrew Moon.
Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
ChaCha20 is a high speed 256-bit key size stream cipher algorithm designed by
Daniel J. Bernstein. It is further specified in RFC7539 for use in IETF
protocols as a building block for the ChaCha20-Poly1305 AEAD.
This is a portable C implementation without any architecture specific
optimizations. It uses a 16-byte IV, which includes the 12-byte ChaCha20 nonce
prepended by the initial block counter. Some algorithms require an explicit
counter value, for example the mentioned AEAD construction.
Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The CPU Jitter RNG provides a source of good entropy by
collecting CPU executing time jitter. The entropy in the CPU
execution time jitter is magnified by the CPU Jitter Random
Number Generator. The CPU Jitter Random Number Generator uses
the CPU execution timing jitter to generate a bit stream
which complies with different statistical measurements that
determine the bit stream is random.
The CPU Jitter Random Number Generator delivers entropy which
follows information theoretical requirements. Based on these
studies and the implementation, the caller can assume that
one bit of data extracted from the CPU Jitter Random Number
Generator holds one bit of entropy.
The CPU Jitter Random Number Generator provides a decentralized
source of entropy, i.e. every caller can operate on a private
state of the entropy pool.
The RNG does not have any dependencies on any other service
in the kernel. The RNG only needs a high-resolution time
stamp.
Further design details, the cryptographic assessment and
large array of test results are documented at
http://www.chronox.de/jent.html.
CC: Andreas Steffen <andreas.steffen@strongswan.org>
CC: Theodore Ts'o <tytso@mit.edu>
CC: Sandy Harris <sandyinchina@gmail.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds a new AEAD IV generator echainiv. It is intended
to replace the existing skcipher IV generator eseqiv.
If the underlying AEAD algorithm is using the old AEAD interface,
then echainiv will simply use its IV generator.
Otherwise, echainiv will encrypt a counter just like eseqiv but
it'll first xor it against a previously stored IV similar to
chainiv.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Enable compilation of the AEAD AF_ALG support and provide a Kconfig
option to compile the AEAD AF_ALG support.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Enable compilation of the RNG AF_ALG support and provide a Kconfig
option to compile the RNG AF_ALG support.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch introduces the multi-buffer crypto daemon which is responsible
for submitting crypto jobs in a work queue to the responsible multi-buffer
crypto algorithm. The idea of the multi-buffer algorihtm is to put
data streams from multiple jobs in a wide (AVX2) register and then
take advantage of SIMD instructions to do crypto computation on several
buffers simultaneously.
The multi-buffer crypto daemon is also responsbile for flushing the
remaining buffers to complete the computation if no new buffers arrive
for a while.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch removes the build-time test that ensures at least one RNG
is set. Instead we will simply not build drbg if no options are set
through Kconfig.
This also fixes a typo in the name of the Kconfig option CRYTPO_DRBG
(should be CRYPTO_DRBG).
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We added the soft module dependency of crc32c module alias
to generic crc32c module so other hardware accelerated crc32c
modules could get loaded and used before the generic version.
We also renamed the crypto/crc32c.c containing the generic
crc32c crypto computation to crypto/crc32c_generic.c according
to convention.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Disabling compiler optimizations can be fragile, since a new
optimization could be added to -O0 or -Os that breaks the assumptions
the code is making.
Instead of disabling compiler optimizations, use a dummy inline assembly
(based on RELOC_HIDE) to block the problematic kinds of optimization,
while still allowing other optimizations to be applied to the code.
The dummy inline assembly is added after every OR, and has the
accumulator variable as its input and output. The compiler is forced to
assume that the dummy inline assembly could both depend on the
accumulator variable and change the accumulator variable, so it is
forced to compute the value correctly before the inline assembly, and
cannot assume anything about its value after the inline assembly.
This change should be enough to make crypto_memneq work correctly (with
data-independent timing) even if it is inlined at its call sites. That
can be done later in a followup patch.
Compile-tested on x86_64.
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.eti.br>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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
...
This patch provides a single place for information about hash algorithms,
such as hash sizes and kernel driver names, which will be used by IMA
and the public key code.
Changelog:
- Fix sparse and checkpatch warnings
- Move hash algo enums to uapi for userspace signing functions.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-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>
Create a generic version of ablk_helper so it can be reused
by other architectures.
Acked-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Unfortunately, even with a softdep some distros fail to include
the necessary modules in the initrd. Therefore this patch adds
a fallback path to restore existing behaviour where we cannot
load the new crypto crct10dif algorithm.
In order to do this, the underlying crct10dif has been split out
from the crypto implementation so that it can be used on the
fallback path.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch reinstates commits
67822649d739761214ee0b95a7f85731d939625a2d31e518a4
Now that module softdeps are in the kernel we can use that to resolve
the boot issue which cause the revert.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto fixes from Herbert Xu:
"This push fixes a memory corruption issue in caam, as well as
reverting the new optimised crct10dif implementation as it breaks boot
on initrd systems.
Hopefully crct10dif will be reinstated once the supporting code is
added so that it doesn't break boot"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
Revert "crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework"
crypto: caam - Fixed the memory out of bound overwrite issue
This reverts commits
67822649d739761214ee0b95a7f85731d939625a2d31e518a4
Unfortunately this change broke boot on some systems that used an
initrd which does not include the newly created crct10dif modules.
As these modules are required by sd_mod under certain configurations
this is a serious problem.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add support for lz4 and lz4hc compression algorithm using the lib/lz4/*
codebase.
[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Chanho Min <chanho.min@lge.com>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When CRC T10 DIF is calculated using the crypto transform framework, we
wrap the crc_t10dif function call to utilize it. This allows us to
take advantage of any accelerated CRC T10 DIF transform that is
plugged into the crypto framework.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Patch adds support for NIST recommended block cipher mode CMAC to CryptoAPI.
This work is based on Tom St Denis' earlier patch,
http://marc.info/?l=linux-crypto-vger&m=135877306305466&w=2
Cc: Tom St Denis <tstdenis@elliptictech.com>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
