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* crypto: remove CONFIG_CRYPTO_STATSEric Biggers2024-04-021-30/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove support for the "Crypto usage statistics" feature (CONFIG_CRYPTO_STATS). This feature does not appear to have ever been used, and it is harmful because it significantly reduces performance and is a large maintenance burden. Covering each of these points in detail: 1. Feature is not being used Since these generic crypto statistics are only readable using netlink, it's fairly straightforward to look for programs that use them. I'm unable to find any evidence that any such programs exist. For example, Debian Code Search returns no hits except the kernel header and kernel code itself and translations of the kernel header: https://codesearch.debian.net/search?q=CRYPTOCFGA_STAT&literal=1&perpkg=1 The patch series that added this feature in 2018 (https://lore.kernel.org/linux-crypto/1537351855-16618-1-git-send-email-clabbe@baylibre.com/) said "The goal is to have an ifconfig for crypto device." This doesn't appear to have happened. It's not clear that there is real demand for crypto statistics. Just because the kernel provides other types of statistics such as I/O and networking statistics and some people find those useful does not mean that crypto statistics are useful too. Further evidence that programs are not using CONFIG_CRYPTO_STATS is that it was able to be disabled in RHEL and Fedora as a bug fix (https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/2947). Even further evidence comes from the fact that there are and have been bugs in how the stats work, but they were never reported. For example, before Linux v6.7 hash stats were double-counted in most cases. There has also never been any documentation for this feature, so it might be hard to use even if someone wanted to. 2. CONFIG_CRYPTO_STATS significantly reduces performance Enabling CONFIG_CRYPTO_STATS significantly reduces the performance of the crypto API, even if no program ever retrieves the statistics. This primarily affects systems with a large number of CPUs. For example, https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039576 reported that Lustre client encryption performance improved from 21.7GB/s to 48.2GB/s by disabling CONFIG_CRYPTO_STATS. It can be argued that this means that CONFIG_CRYPTO_STATS should be optimized with per-cpu counters similar to many of the networking counters. But no one has done this in 5+ years. This is consistent with the fact that the feature appears to be unused, so there seems to be little interest in improving it as opposed to just disabling it. It can be argued that because CONFIG_CRYPTO_STATS is off by default, performance doesn't matter. But Linux distros tend to error on the side of enabling options. The option is enabled in Ubuntu and Arch Linux, and until recently was enabled in RHEL and Fedora (see above). So, even just having the option available is harmful to users. 3. CONFIG_CRYPTO_STATS is a large maintenance burden There are over 1000 lines of code associated with CONFIG_CRYPTO_STATS, spread among 32 files. It significantly complicates much of the implementation of the crypto API. After the initial submission, many fixes and refactorings have consumed effort of multiple people to keep this feature "working". We should be spending this effort elsewhere. Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* crypto: api - Fix CRYPTO_USER checks for report functionOndrej Mosnacek2023-05-021-1/+1
| | | | | | | | | | Checking the config via ifdef incorrectly compiles out the report functions when CRYPTO_USER is set to =m. Fix it by using IS_ENABLED() instead. Fixes: c0f9e01dd266 ("crypto: api - Check CRYPTO_USER instead of NET for report") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* crypto: api - Check CRYPTO_USER instead of NET for reportHerbert Xu2023-03-141-8/+4
| | | | | | | | | | The report function is currently conditionalised on CONFIG_NET. As it's only used by CONFIG_CRYPTO_USER, conditionalising on that instead of CONFIG_NET makes more sense. This gets rid of a rarely used code-path. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* crypto: kpp - Count error stats differentlyHerbert Xu2023-03-141-7/+34
| | | | | | | | | | | | | | | | Move all stat code specific to kpp into the kpp code. While we're at it, change the stats so that bytes and counts are always incremented even in case of error. This allows the reference counting to be removed as we can now increment the counters prior to the operation. After the operation we simply increase the error count if necessary. This is safe as errors can only occur synchronously (or rather, the existing code already ignored asynchronous errors which are only visible to the callback function). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* crypto: add crypto_has_kpp()Hannes Reinecke2022-08-031-0/+6
| | | | | | | | | | | | | Add helper function to determine if a given key-agreement protocol primitive is supported. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* crypto: kpp - provide support for KPP spawnsNicolai Stange2022-03-021-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The upcoming support for the RFC 7919 ffdhe group parameters will be made available in the form of templates like "ffdhe2048(dh)", "ffdhe3072(dh)" and so on. Template instantiations thereof would wrap the inner "dh" kpp_alg and also provide kpp_alg services to the outside again. The primitves needed for providing kpp_alg services from template instances have been introduced with the previous patch. Continue this work now and implement everything needed for enabling template instances to make use of inner KPP algorithms like "dh". More specifically, define a struct crypto_kpp_spawn in close analogy to crypto_skcipher_spawn, crypto_shash_spawn and alike. Implement a crypto_grab_kpp() and crypto_drop_kpp() pair for binding such a spawn to some inner kpp_alg and for releasing it respectively. Template implementations can instantiate transforms from the underlying kpp_alg by means of the new crypto_spawn_kpp(). Finally, provide the crypto_spawn_kpp_alg() helper for accessing a spawn's underlying kpp_alg during template instantiation. Annotate everything with proper kernel-doc comments, even though include/crypto/internal/kpp.h is not considered for the generated docs. Signed-off-by: Nicolai Stange <nstange@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* crypto: kpp - provide support for KPP template instancesNicolai Stange2022-03-021-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The upcoming support for the RFC 7919 ffdhe group parameters will be made available in the form of templates like "ffdhe2048(dh)", "ffdhe3072(dh)" and so on. Template instantiations thereof would wrap the inner "dh" kpp_alg and also provide kpp_alg services to the outside again. Furthermore, it might be perhaps be desirable to provide KDF templates in the future, which would similarly wrap an inner kpp_alg and present themselves to the outside as another kpp_alg, transforming the shared secret on its way out. Introduce the bits needed for supporting KPP template instances. Everything related to inner kpp_alg spawns potentially being held by such template instances will be deferred to a subsequent patch in order to facilitate review. Define struct struct kpp_instance in close analogy to the already existing skcipher_instance, shash_instance and alike, but wrapping a struct kpp_alg. Implement the new kpp_register_instance() template instance registration primitive. Provide some helper functions for - going back and forth between a generic struct crypto_instance and the new struct kpp_instance, - obtaining the instantiating kpp_instance from a crypto_kpp transform and - for accessing a given kpp_instance's implementation specific context data. Annotate everything with proper kernel-doc comments, even though include/crypto/internal/kpp.h is not considered for the generated docs. Signed-off-by: Nicolai Stange <nstange@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2019-05-301-6/+1
| | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* crypto: user - clean up report structure copyingEric Biggers2018-11-091-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There have been a pretty ridiculous number of issues with initializing the report structures that are copied to userspace by NETLINK_CRYPTO. Commit 4473710df1f8 ("crypto: user - Prepare for CRYPTO_MAX_ALG_NAME expansion") replaced some strncpy()s with strlcpy()s, thereby introducing information leaks. Later two other people tried to replace other strncpy()s with strlcpy() too, which would have introduced even more information leaks: - https://lore.kernel.org/patchwork/patch/954991/ - https://patchwork.kernel.org/patch/10434351/ Commit cac5818c25d0 ("crypto: user - Implement a generic crypto statistics") also uses the buggy strlcpy() approach and therefore leaks uninitialized memory to userspace. A fix was proposed, but it was originally incomplete. Seeing as how apparently no one can get this right with the current approach, change all the reporting functions to: - Start by memsetting the report structure to 0. This guarantees it's always initialized, regardless of what happens later. - Initialize all strings using strscpy(). This is safe after the memset, ensures null termination of long strings, avoids unnecessary work, and avoids the -Wstringop-truncation warnings from gcc. - Use sizeof(var) instead of sizeof(type). This is more robust against copy+paste errors. For simplicity, also reuse the -EMSGSIZE return value from nla_put(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* crypto: Replaced gcc specific attributes with macros from compiler.hGideon Israel Dsouza2017-01-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | Continuing from this commit: 52f5684c8e1e ("kernel: use macros from compiler.h instead of __attribute__((...))") I submitted 4 total patches. They are part of task I've taken up to increase compiler portability in the kernel. I've cleaned up the subsystems under /kernel /mm /block and /security, this patch targets /crypto. There is <linux/compiler.h> which provides macros for various gcc specific constructs. Eg: __weak for __attribute__((weak)). I've cleaned all instances of gcc specific attributes with the right macros for the crypto subsystem. I had to make one additional change into compiler-gcc.h for the case when one wants to use this: __attribute__((aligned) and not specify an alignment factor. From the gcc docs, this will result in the largest alignment for that data type on the target machine so I've named the macro __aligned_largest. Please advise if another name is more appropriate. Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* crypto: kpp - Key-agreement Protocol Primitives API (KPP)Salvatore Benedetto2016-06-231-0/+123
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>