- 10 6月, 2017 1 次提交
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由 Tudor-Dan Ambarus 提交于
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: NTudor Ambarus <tudor.ambarus@microchip.com> Reviewed-by: NStephan Müller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 11 2月, 2017 2 次提交
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由 Arnd Bergmann 提交于
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: NArnd Bergmann <arnd@arndb.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Ard Biesheuvel 提交于
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: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 30 11月, 2016 1 次提交
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由 David Michael 提交于
Both asn1 headers are included by rsa_helper.c, so rsa_helper.o should explicitly depend on them. Signed-off-by: NDavid Michael <david.michael@coreos.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 28 11月, 2016 1 次提交
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由 Herbert Xu 提交于
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: NHerbert Xu <herbert@gondor.apana.org.au>
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- 01 11月, 2016 1 次提交
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由 Giovanni Cabiddu 提交于
Fix dependency between acomp and scomp that appears when acomp is built as module Signed-off-by: NGiovanni Cabiddu <giovanni.cabiddu@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 25 10月, 2016 2 次提交
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由 Giovanni Cabiddu 提交于
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: NGiovanni Cabiddu <giovanni.cabiddu@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Giovanni Cabiddu 提交于
Add acomp, an asynchronous compression api that uses scatterlist buffers. Signed-off-by: NGiovanni Cabiddu <giovanni.cabiddu@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 18 7月, 2016 1 次提交
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由 Herbert Xu 提交于
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: NHerbert Xu <herbert@gondor.apana.org.au>
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- 23 6月, 2016 3 次提交
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由 Salvatore Benedetto 提交于
* 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: NSalvatore Benedetto <salvatore.benedetto@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Salvatore Benedetto 提交于
* Implement MPI based Diffie-Hellman under kpp API * Test provided uses data generad by OpenSSL Signed-off-by: NSalvatore Benedetto <salvatore.benedetto@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Salvatore Benedetto 提交于
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: NSalvatore Benedetto <salvatore.benedetto@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 20 6月, 2016 1 次提交
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由 Jeff Garzik 提交于
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: NJeff Garzik <jgarzik@redhat.com> Signed-off-by: NRaveendra Padasalagi <raveendra.padasalagi@broadcom.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 01 2月, 2016 1 次提交
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由 Baolin Wang 提交于
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=ffbbdd21) Signed-off-by: NBaolin Wang <baolin.wang@linaro.org> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 30 1月, 2016 1 次提交
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由 Herbert Xu 提交于
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: NHerbert Xu <herbert@gondor.apana.org.au>
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- 27 1月, 2016 1 次提交
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由 Joonsoo Kim 提交于
It is unused now, so remove it. Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 09 12月, 2015 1 次提交
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由 Andrzej Zaborowski 提交于
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: NAndrew Zaborowski <andrew.zaborowski@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 15 10月, 2015 1 次提交
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由 Stephan Mueller 提交于
Hook keywrap source code into Kconfig and Makefile Signed-off-by: NStephan Mueller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 14 10月, 2015 1 次提交
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由 Tadeusz Struk 提交于
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: NTadeusz Struk <tadeusz.struk@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 21 8月, 2015 1 次提交
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由 Herbert Xu 提交于
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: NHerbert Xu <herbert@gondor.apana.org.au>
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- 17 8月, 2015 1 次提交
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由 Herbert Xu 提交于
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: 149a3971 ("crypto: aead - Add type-safe geniv init/exit helpers") Reported-by: Nkbuild test robot <fengguang.wu@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 25 6月, 2015 1 次提交
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由 Stephan Mueller 提交于
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: NStephan Mueller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 17 6月, 2015 2 次提交
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由 Tadeusz Struk 提交于
Add a new rsa generic SW implementation. This implements only cryptographic primitives. Signed-off-by: NTadeusz Struk <tadeusz.struk@intel.com> Added select on ASN1. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Tadeusz Struk 提交于
Add Public Key Encryption API. Signed-off-by: NTadeusz Struk <tadeusz.struk@intel.com> Made CRYPTO_AKCIPHER invisible like other type config options. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 09 6月, 2015 1 次提交
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由 Stephan Mueller 提交于
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: NStephan Mueller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 04 6月, 2015 4 次提交
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由 Herbert Xu 提交于
This patch removes krng so that DRBG can take its place. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Martin Willi 提交于
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: NMartin Willi <martin@strongswan.org> Acked-by: NSteffen Klassert <steffen.klassert@secunet.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Martin Willi 提交于
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: NMartin Willi <martin@strongswan.org> Acked-by: NSteffen Klassert <steffen.klassert@secunet.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Martin Willi 提交于
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: NMartin Willi <martin@strongswan.org> Acked-by: NSteffen Klassert <steffen.klassert@secunet.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 27 5月, 2015 1 次提交
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由 Stephan Mueller 提交于
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: NStephan Mueller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 22 5月, 2015 1 次提交
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由 Herbert Xu 提交于
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: NHerbert Xu <herbert@gondor.apana.org.au>
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- 04 3月, 2015 1 次提交
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由 Stephan Mueller 提交于
Enable compilation of the AEAD AF_ALG support and provide a Kconfig option to compile the AEAD AF_ALG support. Signed-off-by: NStephan Mueller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 29 12月, 2014 1 次提交
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由 Stephan Mueller 提交于
Enable compilation of the RNG AF_ALG support and provide a Kconfig option to compile the RNG AF_ALG support. Signed-off-by: NStephan Mueller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 25 8月, 2014 1 次提交
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由 Tim Chen 提交于
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: NTim Chen <tim.c.chen@linux.intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 04 7月, 2014 1 次提交
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由 Herbert Xu 提交于
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: NHerbert Xu <herbert@gondor.apana.org.au>
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- 20 6月, 2014 1 次提交
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由 Stephan Mueller 提交于
Signed-off-by: NStephan Mueller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 25 2月, 2014 1 次提交
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由 Tim Chen 提交于
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: NTim Chen <tim.c.chen@linux.intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 05 12月, 2013 1 次提交
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由 Cesar Eduardo Barros 提交于
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: NCesar Eduardo Barros <cesarb@cesarb.eti.br> Acked-by: NDaniel Borkmann <dborkman@redhat.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 26 10月, 2013 1 次提交
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由 Dmitry Kasatkin 提交于
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: NDmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 07 10月, 2013 1 次提交
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由 James Yonan 提交于
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/2013/2/10/131Signed-off-by: NJames Yonan <james@openvpn.net> Signed-off-by: NDaniel Borkmann <dborkman@redhat.com> Cc: Florian Weimer <fw@deneb.enyo.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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