- Feb 11, 2022
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Stephan Müller authored
FIPS 140 requires a minimum security strength of 112 bits. This implies that the HMAC key must not be smaller than 112 in FIPS mode. This restriction implies that the test vectors for HMAC that have a key that is smaller than 112 bits must be disabled when FIPS support is compiled. Signed-off-by:
Stephan Mueller <smueller@chronox.de> Signed-off-by:
Herbert Xu <herbert@gondor.apana.org.au>
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Stephan Müller authored
By adding the support for the flag fips_skip, hash / HMAC test vectors may be marked to be not applicable in FIPS mode. Such vectors are silently skipped in FIPS mode. Signed-off-by:
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- Feb 04, 2022
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Tianjia Zhang authored
The multibuffer algorithms was removed already in 2018, so it is necessary to clear the test code left by tcrypt. Suggested-by:
Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Acked-by:
Ard Biesheuvel <ardb@kernel.org> Signed-off-by:
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- Jan 30, 2022
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Ard Biesheuvel authored
The C standard does not support dereferencing pointers that are not aligned with respect to the pointed-to type, and doing so is technically undefined behavior, even if the underlying hardware supports it. This means that conditionally dereferencing such pointers based on whether CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y is not the right thing to do, and actually results in alignment faults on ARM, which are fixed up on a slow path. Instead, we should use the unaligned accessors in such cases: on architectures that don't care about alignment, they will result in identical codegen whereas, e.g., codegen on ARM will avoid doubleword loads and stores but use ordinary ones, which are able to tolerate misalignment. Link: https://lore.kernel.org/linux-crypto/CAHk-=wiKkdYLY0bv+nXrcJz3NH9mAqPAafX7PpW5EwVtxsEu7Q@mail.gmail.com/ Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Reviewed-by:
Eric Biggers <ebiggers@google.com> Signed-off-by:
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Herbert Xu authored
The function crypto_authenc_decrypt_tail discards its flags argument and always relies on the flags from the original request when starting its sub-request. This is clearly wrong as it may cause the SLEEPABLE flag to be set when it shouldn't. Fixes: 92d95ba9 ("crypto: authenc - Convert to new AEAD interface") Reported-by:
Corentin Labbe <clabbe.montjoie@gmail.com> Signed-off-by:
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Eric Biggers authored
The new convention for akcipher_alg::verify makes it unclear which values are the lengths of the signature and digest. Add local variables to make it clearer what is going on. Also rename the digest_size variable in pkcs1pad_sign(), as it is actually the digest *info* size, not the digest size which is different. Signed-off-by:
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Eric Biggers authored
Before checking whether the expected digest_info is present, we need to check that there are enough bytes remaining. Fixes: a49de377 ("crypto: Add hash param to pkcs1pad") Cc: <stable@vger.kernel.org> # v4.6+ Cc: Tadeusz Struk <tadeusz.struk@linaro.org> Signed-off-by:
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Eric Biggers authored
RSA PKCS#1 v1.5 signatures are required to be the same length as the RSA key size. RFC8017 specifically requires the verifier to check this (https://datatracker.ietf.org/doc/html/rfc8017#section-8.2.2). Commit a49de377 ("crypto: Add hash param to pkcs1pad") changed the kernel to allow longer signatures, but didn't explain this part of the change; it seems to be unrelated to the rest of the commit. Revert this change, since it doesn't appear to be correct. We can be pretty sure that no one is relying on overly-long signatures (which would have to be front-padded with zeroes) being supported, given that they would have been broken since commit c7381b01 ("crypto: akcipher - new verify API for public key algorithms"). Fixes: a49de377 ("crypto: Add hash param to pkcs1pad") Cc: <stable@vger.kernel.org> # v4.6+ Cc: Tadeusz Struk <tadeusz.struk@linaro.org> Suggested-by:
Vitaly Chikunov <vt@altlinux.org> Signed-off-by:
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Eric Biggers authored
Commit c7381b01 ("crypto: akcipher - new verify API for public key algorithms") changed akcipher_alg::verify to take in both the signature and the actual hash and do the signature verification, rather than just return the hash expected by the signature as was the case before. To do this, it implemented a hack where the signature and hash are concatenated with each other in one scatterlist. Obviously, for this to work correctly, akcipher_alg::verify needs to correctly extract the two items from the scatterlist it is given. Unfortunately, it doesn't correctly extract the hash in the case where the signature is longer than the RSA key size, as it assumes that the signature's length is equal to the RSA key size. This causes a prefix of the hash, or even the entire hash, to be taken from the *signature*. (Note, the case of a signature longer than the RSA key size should not be allowed in the first place; a separate patch will fix that.) It is unclear whether the resulting scheme has any useful security properties. Fix this by correctly extracting the hash from the scatterlist. Fixes: c7381b01 ("crypto: akcipher - new verify API for public key algorithms") Cc: <stable@vger.kernel.org> # v5.2+ Reviewed-by:
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Eric Biggers authored
The pkcs1pad template can be instantiated with an arbitrary akcipher algorithm, which doesn't make sense; it is specifically an RSA padding scheme. Make it check that the underlying algorithm really is RSA. Fixes: 3d5b1ecd ("crypto: rsa - RSA padding algorithm") Cc: <stable@vger.kernel.org> # v4.5+ Signed-off-by:
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Herbert Xu authored
In addition to sha256 we must also enable hmac for the kdf self-test to work. Reported-by:
kernel test robot <oliver.sang@intel.com> Fixes: 304b4ace ("crypto: kdf - select SHA-256 required...") Fixes: 026a733e ("crypto: kdf - add SP800-108 counter key...") Signed-off-by:
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Herbert Xu authored
As testmgr is part of cryptomgr which was designed to be unloadable as a module, it shouldn't export any symbols for other crypto modules to use as that would prevent it from being unloaded. All its functionality is meant to be accessed through notifiers. The symbol crypto_simd_disabled_for_test was added to testmgr which caused it to be pinned as a module if its users were also loaded. This patch moves it out of testmgr and into crypto/algapi.c so cryptomgr can again be unloaded and replaced on demand. Signed-off-by:
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- Jan 28, 2022
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Tianjia Zhang authored
tcrypt supports testing of SM3 hash algorithms that use AVX instruction acceleration. In order to add the sm3 asynchronous test to the appropriate position, shift the testcase sequence number of the multi buffer backward and start from 450. Signed-off-by:
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Tianjia Zhang authored
This patch adds AVX assembly accelerated implementation of SM3 secure hash algorithm. From the benchmark data, compared to pure software implementation sm3-generic, the performance increase is up to 38%. The main algorithm implementation based on SM3 AES/BMI2 accelerated work by libgcrypt at: https://gnupg.org/software/libgcrypt/index.html Benchmark on Intel i5-6200U 2.30GHz, performance data of two implementations, pure software sm3-generic and sm3-avx acceleration. The data comes from the 326 mode and 422 mode of tcrypt. The abscissas are different lengths of per update. The data is tabulated and the unit is Mb/s: update-size | 16 64 256 1024 2048 4096 8192 ------------+------------------------------------------------------- sm3-generic | 105.97 129.60 182.12 189.62 188.06 193.66 194.88 sm3-avx | 119.87 163.05 244.44 260.92 257.60 264.87 265.88 Signed-off-by:
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Tianjia Zhang authored
SM3 generic library is stand-alone implementation, it is necessary making the sm3-generic implementation to depends on SM3 library. The functions crypto_sm3_*() provided by sm3_generic is no longer exported. Signed-off-by:
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Tianjia Zhang authored
SM3 generic library is stand-alone implementation, it is necessary for the calculation of sm2 z digest to depends on SM3 library instead of sm3-generic. Signed-off-by:
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- Jan 18, 2022
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Justin M. Forbes authored
Commit 6048fdcc ("lib/crypto: blake2s: include as built-in") took away a number of prompt texts from other crypto libraries. This makes values flip from built-in to module when oldconfig runs, and causes problems when these crypto libs need to be built in for thingslike BIG_KEYS. Fixes: 6048fdcc ("lib/crypto: blake2s: include as built-in") Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: linux-crypto@vger.kernel.org Signed-off-by:
Justin M. Forbes <jforbes@fedoraproject.org> [Jason: - moved menu into submenu of lib/ instead of root menu - fixed chacha sub-dependencies for CONFIG_CRYPTO] Signed-off-by:
Jason A. Donenfeld <Jason@zx2c4.com>
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- Jan 08, 2022
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Andrew Zaborowski authored
There are non-root X.509 v3 certificates in use out there that contain no Authority Key Identifier extension (RFC5280 section 4.2.1.1). For trust verification purposes the kernel asymmetric key type keeps two struct asymmetric_key_id instances that the key can be looked up by, and another two to look up the key's issuer. The x509 public key type and the PKCS7 type generate them from the SKID and AKID extensions in the certificate. In effect current code has no way to look up the issuer certificate for verification without the AKID. To remedy this, add a third asymmetric_key_id blob to the arrays in both asymmetric_key_id's (for certficate subject) and in the public_keys_signature's auth_ids (for issuer lookup), using just raw subject and issuer DNs from the certificate. Adapt asymmetric_key_ids() and its callers to use the third ID for lookups when none of the other two are available. Attempt to keep the logic intact when they are, to minimise behaviour changes. Adapt the restrict functions' NULL-checks to include that ID too. Do not modify the lookup logic in pkcs7_verify.c, the AKID extensions are still required there. Internally use a new "dn:" prefix to the search specifier string generated for the key lookup in find_asymmetric_key(). This tells asymmetric_key_match_preparse to only match the data against the raw DN in the third ID and shouldn't conflict with search specifiers already in use. In effect implement what (2) in the struct asymmetric_key_id comment (include/keys/asymmetric-type.h) is probably talking about already, so do not modify that comment. It is also how "openssl verify" looks up issuer certificates without the AKID available. Lookups by the raw DN are unambiguous only provided that the CAs respect the condition in RFC5280 4.2.1.1 that the AKID may only be omitted if the CA uses a single signing key. The following is an example of two things that this change enables. A self-signed ceritficate is generated following the example from https://letsencrypt.org/docs/certificates-for-localhost/ , and can be looked up by an identifier and verified against itself by linking to a restricted keyring -- both things not possible before due to the missing AKID extension: $ openssl req -x509 -out localhost.crt -outform DER -keyout localhost.key \ -newkey rsa:2048 -nodes -sha256 \ -subj '/CN=localhost' -extensions EXT -config <( \ echo -e "[dn]\nCN=localhost\n[req]\ndistinguished_name = dn\n[EXT]\n" \ "subjectAltName=DNS:localhost\nkeyUsage=digitalSignature\n" \ "extendedKeyUsage=serverAuth") $ keyring=`keyctl newring test @u` $ trusted=`keyctl padd asymmetric trusted $keyring < localhost.crt`; \ echo $trusted 39726322 $ keyctl search $keyring asymmetric dn:3112301006035504030c096c6f63616c686f7374 39726322 $ keyctl restrict_keyring $keyring asymmetric key_or_keyring:$trusted $ keyctl padd asymmetric verified $keyring < localhost.crt Signed-off-by:
Andrew Zaborowski <andrew.zaborowski@intel.com> Reviewed-by:
Jarkko Sakkinen <jarkko@kernel.org> Acked-by:
David Howells <dhowells@redhat.com> Signed-off-by:
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- Jan 06, 2022
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Jiasheng Jiang authored
Because of the possible alloc failure of the alloc_page(), it could return NULL pointer. And there is a check below the sg_assign_page(). But it will be more logical to move the NULL check before the sg_assign_page(). Signed-off-by:
Jiasheng Jiang <jiasheng@iscas.ac.cn> Signed-off-by:
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Jason A. Donenfeld authored
In preparation for using blake2s in the RNG, we change the way that it is wired-in to the build system. Instead of using ifdefs to select the right symbol, we use weak symbols. And because ARM doesn't need the generic implementation, we make the generic one default only if an arch library doesn't need it already, and then have arch libraries that do need it opt-in. So that the arch libraries can remain tristate rather than bool, we then split the shash part from the glue code. Acked-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: linux-kbuild@vger.kernel.org Cc: linux-crypto@vger.kernel.org Signed-off-by:
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- Dec 31, 2021
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Stephan Müller authored
The self test of the KDF is based on SHA-256. Thus, this algorithm must be present as otherwise a warning is issued. Reported-by:
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Tianjia Zhang authored
crypto_sha256_init() and sha256_base_init() are the same repeated implementations, remove the crypto_sha256_init() in generic implementation, sha224 is the same process. Signed-off-by:
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Stephan Müller authored
The output n bits can receive more than n bits of min entropy, of course, but the fixed output of the conditioning function can only asymptotically approach the output size bits of min entropy, not attain that bound. Random maps will tend to have output collisions, which reduces the creditable output entropy (that is what SP 800-90B Section 3.1.5.1.2 attempts to bound). The value "64" is justified in Appendix A.4 of the current 90C draft, and aligns with NIST's in "epsilon" definition in this document, which is that a string can be considered "full entropy" if you can bound the min entropy in each bit of output to at least 1-epsilon, where epsilon is required to be <= 2^(-32). Note, this patch causes the Jitter RNG to cut its performance in half in FIPS mode because the conditioning function of the LFSR produces 64 bits of entropy in one block. The oversampling requires that additionally 64 bits of entropy are sampled from the noise source. If the condit...
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- Dec 13, 2021
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Eric W. Biederman authored
Update module_put_and_exit to call kthread_exit instead of do_exit. Change the name to reflect this change in functionality. All of the users of module_put_and_exit are causing the current kthread to exit so this change makes it clear what is happening. There is no functional change. Signed-off-by:"Eric W. Biederman" <ebiederm@xmission.com>
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- Dec 11, 2021
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Nicolai Stange authored
The jitterentropy collection loop in jent_gen_entropy() can in principle run indefinitely without making any progress if it only receives stuck measurements as determined by jent_stuck(). After 31 consecutive stuck samples, the Repetition Count Test (RCT) would fail anyway and the jitterentropy RNG instances moved into ->health_failure == 1 state. jent_gen_entropy()'s caller, jent_read_entropy() would then check for this ->health_failure condition and return an error if found set. It follows that there's absolutely no point in continuing the collection loop in jent_gen_entropy() once the RCT has failed. Make the jitterentropy collection loop more robust by terminating it upon jent_health_failure() so that it won't continue to run indefinitely without making any progress. Signed-off-by:
Nicolai Stange <nstange@suse.de> Reviewed-by:
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Nicolai Stange authored
The jitterentropy's Repetition Count Test (RCT) as well as the Adaptive Proportion Test (APT) are run unconditionally on any collected samples. However, their result, i.e. ->health_failure, will only get checked if fips_enabled is set, c.f. the jent_health_failure() wrapper. I would argue that a RCT or APT failure indicates that something's seriously off and that this should always be reported as an error, independently of whether FIPS mode is enabled or not: it should be up to callers whether or not and how to handle jitterentropy failures. Make jent_health_failure() to unconditionally return ->health_failure, independent of whether fips_enabled is set. Note that fips_enabled isn't accessed from the jitterentropy code anymore now. Remove the linux/fips.h include as well as the jent_fips_enabled() wrapper. Signed-off-by:
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Nicolai Stange authored
A subsequent patch will make the jitterentropy RNG to unconditionally report health test errors back to callers, independent of whether fips_enabled is set or not. The DRBG needs access to a functional jitterentropy instance only in FIPS mode (because it's the only SP800-90B compliant entropy source as it currently stands). Thus, it is perfectly fine for the DRBGs to obtain entropy from the jitterentropy source only on a best effort basis if fips_enabled is off. Make the DRBGs to ignore jitterentropy failures if fips_enabled is not set. Signed-off-by:
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Guo Zhengkui authored
Remove a duplicate #include <linux/fips.h>. Signed-off-by:
Guo Zhengkui <guozhengkui@vivo.com> Signed-off-by:
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- Nov 26, 2021
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Stephan Müller authored
On Dec 31 2023 NIST sunsets TDES for FIPS use. To prevent FIPS validations to be completed in the future to be affected by the TDES sunsetting, disallow TDES already now. Otherwise a FIPS validation would need to be "touched again" end 2023 to handle TDES accordingly. Signed-off-by:
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Stephan Müller authored
FIPS disallows DH with keys < 2048 bits. Thus, the kernel should consider the enforcement of this limit. Signed-off-by:
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Stephan Müller authored
FIPS disallows RSA with keys < 2048 bits. Thus, the kernel should consider the enforcement of this limit. Signed-off-by:
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Stephan Müller authored
The APT compares the current time stamp with a pre-set value. The current code only considered the 4 LSB only. Yet, after reviews by mathematicians of the user space Jitter RNG version >= 3.1.0, it was concluded that the APT can be calculated on the 32 LSB of the time delta. Thi change is applied to the kernel. This fixes a bug where an AMD EPYC fails this test as its RDTSC value contains zeros in the LSB. The most appropriate fix would have been to apply a GCD calculation and divide the time stamp by the GCD. Yet, this is a significant code change that will be considered for a future update. Note, tests showed that constantly the GCD always was 32 on these systems, i.e. the 5 LSB were always zero (thus failing the APT since it only considered the 4 LSB for its calculation). Signed-off-by:
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Stephan Müller authored
SP800-108 defines three KDFs - this patch provides the counter KDF implementation. The KDF is implemented as a service function where the caller has to maintain the hash / HMAC state. Apart from this hash/HMAC state, no additional state is required to be maintained by either the caller or the KDF implementation. The key for the KDF is set with the crypto_kdf108_setkey function which is intended to be invoked before the caller requests a key derivation operation via crypto_kdf108_ctr_generate. SP800-108 allows the use of either a HMAC or a hash as crypto primitive for the KDF. When a HMAC primtive is intended to be used, crypto_kdf108_setkey must be used to set the HMAC key. Otherwise, for a hash crypto primitve crypto_kdf108_ctr_generate can be used immediately after allocating the hash handle. Signed-off-by:
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Nicolai Stange authored
In contrast to the fully prediction resistant 'pr' DRBGs, the 'nopr' variants get seeded once at boot and reseeded only rarely thereafter, namely only after 2^20 requests have been served each. AFAICT, this reseeding based on the number of requests served is primarily motivated by information theoretic considerations, c.f. NIST SP800-90Ar1, sec. 8.6.8 ("Reseeding"). However, given the relatively large seed lifetime of 2^20 requests, the 'nopr' DRBGs can hardly be considered to provide any prediction resistance whatsoever, i.e. to protect against threats like side channel leaks of the internal DRBG state (think e.g. leaked VM snapshots). This is expected and completely in line with the 'nopr' naming, but as e.g. the "drbg_nopr_hmac_sha512" implementation is potentially being used for providing the "stdrng" and thus, the crypto_default_rng serving the in-kernel crypto, it would certainly be desirable to achieve at least the same level of prediction resistance as get_random_bytes() does. Note that the chacha20 rngs underlying get_random_bytes() get reseeded every CRNG_RESEED_INTERVAL == 5min: the secondary, per-NUMA node rngs from the primary one and the primary rng in turn from the entropy pool, provided sufficient entropy is available. The 'nopr' DRBGs do draw randomness from get_random_bytes() for their initial seed already, so making them to reseed themselves periodically from get_random_bytes() in order to let them benefit from the latter's prediction resistance is not such a big change conceptually. In principle, it would have been also possible to make the 'nopr' DRBGs to periodically invoke a full reseeding operation, i.e. to also consider the jitterentropy source (if enabled) in addition to get_random_bytes() for the seed value. However, get_random_bytes() is relatively lightweight as compared to the jitterentropy generation process and thus, even though the 'nopr' reseeding is supposed to get invoked infrequently, it's IMO still worthwhile to avoid occasional latency spikes for drbg_generate() and stick to get_random_bytes() only. As an additional remark, note that drawing randomness from the non-SP800-90B-conforming get_random_bytes() only won't adversely affect SP800-90A conformance either: the very same is being done during boot via drbg_seed_from_random() already once rng_is_initialized() flips to true and it follows that if the DRBG implementation does conform to SP800-90A now, it will continue to do so. Make the 'nopr' DRBGs to reseed themselves periodically from get_random_bytes() every CRNG_RESEED_INTERVAL == 5min. More specifically, introduce a new member ->last_seed_time to struct drbg_state for recording in units of jiffies when the last seeding operation had taken place. Make __drbg_seed() maintain it and let drbg_generate() invoke a reseed from get_random_bytes() via drbg_seed_from_random() if more than 5min have passed by since the last seeding operation. Be careful to not to reseed if in testing mode though, or otherwise the drbg related tests in crypto/testmgr.c would fail to reproduce the expected output. In order to keep the formatting clean in drbg_generate() wrap the logic for deciding whether or not a reseed is due in a new helper, drbg_nopr_reseed_interval_elapsed(). Signed-off-by: -
Nicolai Stange authored
Now that drbg_prepare_hrng() doesn't do anything but to instantiate a jitterentropy crypto_rng instance, it looks a little odd to have the related error handling at its only caller, drbg_instantiate(). Move the handling of jitterentropy allocation failures from drbg_instantiate() close to the allocation itself in drbg_prepare_hrng(). There is no change in behaviour. Signed-off-by:
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Nicolai Stange authored
get_random_bytes() usually hasn't full entropy available by the time DRBG instances are first getting seeded from it during boot. Thus, the DRBG implementation registers random_ready_callbacks which would in turn schedule some work for reseeding the DRBGs once get_random_bytes() has sufficient entropy available. For reference, the relevant history around handling DRBG (re)seeding in the context of a not yet fully seeded get_random_bytes() is: commit 16b369a9 ("random: Blocking API for accessing nonblocking_pool") commit 4c787990 ("crypto: drbg - add async seeding operation") commit 205a525c ("random: Add callback API for random pool readiness") commit 57225e67 ("crypto: drbg - Use callback API for random readiness") commit c2719503 ("random: Remove kernel blocking API") However, some time later, the initialization state of get_random_bytes() has been made queryable via rng_is_initialized() introduced with commit 9a47249d ("random: Make crng state queryable"). This primitive now allows for streamlining the DRBG reseeding from get_random_bytes() by replacing that aforementioned asynchronous work scheduling from random_ready_callbacks with some simpler, synchronous code in drbg_generate() next to the related logic already present therein. Apart from improving overall code readability, this change will also enable DRBG users to rely on wait_for_random_bytes() for ensuring that the initial seeding has completed, if desired. The previous patches already laid the grounds by making drbg_seed() to record at each DRBG instance whether it was being seeded at a time when rng_is_initialized() still had been false as indicated by ->seeded == DRBG_SEED_STATE_PARTIAL. All that remains to be done now is to make drbg_generate() check for this condition, determine whether rng_is_initialized() has flipped to true in the meanwhile and invoke a reseed from get_random_bytes() if so. Make this move: - rename the former drbg_async_seed() work handler, i.e. the one in charge of reseeding a DRBG instance from get_random_bytes(), to "drbg_seed_from_random()", - change its signature as appropriate, i.e. make it take a struct drbg_state rather than a work_struct and change its return type from "void" to "int" in order to allow for passing error information from e.g. its __drbg_seed() invocation onwards to callers, - make drbg_generate() invoke this drbg_seed_from_random() once it encounters a DRBG instance with ->seeded == DRBG_SEED_STATE_PARTIAL by the time rng_is_initialized() has flipped to true and - prune everything related to the former, random_ready_callback based mechanism. As drbg_seed_from_random() is now getting invoked from drbg_generate() with the ->drbg_mutex being held, it must not attempt to recursively grab it once again. Remove the corresponding mutex operations from what is now drbg_seed_from_random(). Furthermore, as drbg_seed_from_random() can now report errors directly to its caller, there's no need for it to temporarily switch the DRBG's ->seeded state to DRBG_SEED_STATE_UNSEEDED so that a failure of the subsequently invoked __drbg_seed() will get signaled to drbg_generate(). Don't do it then. Signed-off-by:
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Nicolai Stange authored
Since commit 42ea507f ("crypto: drbg - reseed often if seedsource is degraded"), the maximum seed lifetime represented by ->reseed_threshold gets temporarily lowered if the get_random_bytes() source cannot provide sufficient entropy yet, as is common during boot, and restored back to the original value again once that has changed. More specifically, if the add_random_ready_callback() invoked from drbg_prepare_hrng() in the course of DRBG instantiation does not return -EALREADY, that is, if get_random_bytes() has not been fully initialized at this point yet, drbg_prepare_hrng() will lower ->reseed_threshold to a value of 50. The drbg_async_seed() scheduled from said random_ready_callback will eventually restore the original value. A future patch will replace the random_ready_callback based notification mechanism and thus, there will be no add_random_ready_callback() return value anymore which could get compared to -EALREADY. However, there's __drbg_seed() which gets invoked in the course of both, the DRBG instantiation as well as the eventual reseeding from get_random_bytes() in aforementioned drbg_async_seed(), if any. Moreover, it knows about the get_random_bytes() initialization state by the time the seed data had been obtained from it: the new_seed_state argument introduced with the previous patch would get set to DRBG_SEED_STATE_PARTIAL in case get_random_bytes() had not been fully initialized yet and to DRBG_SEED_STATE_FULL otherwise. Thus, __drbg_seed() provides a convenient alternative for managing that ->reseed_threshold lowering and restoring at a central place. Move all ->reseed_threshold adjustment code from drbg_prepare_hrng() and drbg_async_seed() respectively to __drbg_seed(). Make __drbg_seed() lower the ->reseed_threshold to 50 in case its new_seed_state argument equals DRBG_SEED_STATE_PARTIAL and let it restore the original value otherwise. There is no change in behaviour. Signed-off-by:
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Nicolai Stange authored
Currently, the DRBG implementation schedules asynchronous works from random_ready_callbacks for reseeding the DRBG instances with output from get_random_bytes() once the latter has sufficient entropy available. However, as the get_random_bytes() initialization state can get queried by means of rng_is_initialized() now, there is no real need for this asynchronous reseeding logic anymore and it's better to keep things simple by doing it synchronously when needed instead, i.e. from drbg_generate() once rng_is_initialized() has flipped to true. Of course, for this to work, drbg_generate() would need some means by which it can tell whether or not rng_is_initialized() has flipped to true since the last seeding from get_random_bytes(). Or equivalently, whether or not the last seed from get_random_bytes() has happened when rng_is_initialized() was still evaluating to false. As it currently stands, enum drbg_seed_state allows for the representation of two different DRBG seeding states: DRBG_SEED_STATE_UNSEEDED and DRBG_SEED_STATE_FULL. The former makes drbg_generate() to invoke a full reseeding operation involving both, the rather expensive jitterentropy as well as the get_random_bytes() randomness sources. The DRBG_SEED_STATE_FULL state on the other hand implies that no reseeding at all is required for a !->pr DRBG variant. Introduce the new DRBG_SEED_STATE_PARTIAL state to enum drbg_seed_state for representing the condition that a DRBG was being seeded when rng_is_initialized() had still been false. In particular, this new state implies that - the given DRBG instance has been fully seeded from the jitterentropy source (if enabled) - and drbg_generate() is supposed to reseed from get_random_bytes() *only* once rng_is_initialized() turns to true. Up to now, the __drbg_seed() helper used to set the given DRBG instance's ->seeded state to constant DRBG_SEED_STATE_FULL. Introduce a new argument allowing for the specification of the to be written ->seeded value instead. Make the first of its two callers, drbg_seed(), determine the appropriate value based on rng_is_initialized(). The remaining caller, drbg_async_seed(), is known to get invoked only once rng_is_initialized() is true, hence let it pass constant DRBG_SEED_STATE_FULL for the new argument to __drbg_seed(). There is no change in behaviour, except for that the pr_devel() in drbg_generate() would now report "unseeded" for ->pr DRBG instances which had last been seeded when rng_is_initialized() was still evaluating to false. Signed-off-by:
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Nicolai Stange authored
There are two different randomness sources the DRBGs are getting seeded from, namely the jitterentropy source (if enabled) and get_random_bytes(). At initial DRBG seeding time during boot, the latter might not have collected sufficient entropy for seeding itself yet and thus, the DRBG implementation schedules a reseed work from a random_ready_callback once that has happened. This is particularly important for the !->pr DRBG instances, for which (almost) no further reseeds are getting triggered during their lifetime. Because collecting data from the jitterentropy source is a rather expensive operation, the aforementioned asynchronously scheduled reseed work restricts itself to get_random_bytes() only. That is, it in some sense amends the initial DRBG seed derived from jitterentropy output at full (estimated) entropy with fresh randomness obtained from get_random_bytes() once that has been seeded with sufficient entropy itself. With the advent of rng_is_initialized(), there is no real need for doing the reseed operation from an asynchronously scheduled work anymore and a subsequent patch will make it synchronous by moving it next to related logic already present in drbg_generate(). However, for tracking whether a full reseed including the jitterentropy source is required or a "partial" reseed involving only get_random_bytes() would be sufficient already, the boolean struct drbg_state's ->seeded member must become a tristate value. Prepare for this by introducing the new enum drbg_seed_state and change struct drbg_state's ->seeded member's type from bool to that type. For facilitating review, enum drbg_seed_state is made to only contain two members corresponding to the former ->seeded values of false and true resp. at this point: DRBG_SEED_STATE_UNSEEDED and DRBG_SEED_STATE_FULL. A third one for tracking the intermediate state of "seeded from jitterentropy only" will be introduced with a subsequent patch. There is no change in behaviour at this point. Signed-off-by:
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- Nov 19, 2021
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Lei He authored
According to the BER encoding rules, integer value should be encoded as two's complement, and if the highest bit of a positive integer is 1, should add a leading zero-octet. The kernel's built-in RSA algorithm cannot recognize negative numbers when parsing keys, so it can pass this test case. Export the key to file and run the following command to verify the fix result: openssl asn1parse -inform DER -in /path/to/key/file Signed-off-by:
Lei He <helei.sig11@bytedance.com> Signed-off-by:
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