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linux/crypto/jitterentropy.h

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crypto: jitter - add header to fix buildwarnings Fix the following build warnings by adding a header for the definitions shared between jitterentropy.c and jitterentropy-kcapi.c. Fixes the following: crypto/jitterentropy.c:445:5: warning: symbol 'jent_read_entropy' was not declared. Should it be static? crypto/jitterentropy.c:475:18: warning: symbol 'jent_entropy_collector_alloc' was not declared. Should it be static? crypto/jitterentropy.c:509:6: warning: symbol 'jent_entropy_collector_free' was not declared. Should it be static? crypto/jitterentropy.c:516:5: warning: symbol 'jent_entropy_init' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:59:6: warning: symbol 'jent_zalloc' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:64:6: warning: symbol 'jent_zfree' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:69:5: warning: symbol 'jent_fips_enabled' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:74:6: warning: symbol 'jent_panic' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:79:6: warning: symbol 'jent_memcpy' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:93:6: warning: symbol 'jent_get_nstime' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reviewed-by: Stephan Mueller <smueller@chronox.de Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-10-09 12:12:56 +03:00
// SPDX-License-Identifier: GPL-2.0-or-later
crypto: jitter - Allow configuration of memory size The memory size consumed by the Jitter RNG is one contributing factor in the amount of entropy that is gathered. As the amount of entropy directly correlates with the distance of the memory from the CPU, the caches that are possibly present on a given system have an impact on the collected entropy. Thus, the kernel compile time should offer a means to configure the amount of memory used by the Jitter RNG. Although this option could be turned into a runtime option (e.g. a kernel command line option), it should remain a compile time option as otherwise adminsitrators who may not have performed an entropy assessment may select a value that is inappropriate. The default value selected by the configuration is identical to the current Jitter RNG value. Thus, the patch should not lead to any change in the Jitter RNG behavior. To accommodate larger memory buffers, kvzalloc / kvfree is used. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-09-21 14:48:33 +03:00
extern void *jent_kvzalloc(unsigned int len);
extern void jent_kvzfree(void *ptr, unsigned int len);
crypto: jitter - add header to fix buildwarnings Fix the following build warnings by adding a header for the definitions shared between jitterentropy.c and jitterentropy-kcapi.c. Fixes the following: crypto/jitterentropy.c:445:5: warning: symbol 'jent_read_entropy' was not declared. Should it be static? crypto/jitterentropy.c:475:18: warning: symbol 'jent_entropy_collector_alloc' was not declared. Should it be static? crypto/jitterentropy.c:509:6: warning: symbol 'jent_entropy_collector_free' was not declared. Should it be static? crypto/jitterentropy.c:516:5: warning: symbol 'jent_entropy_init' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:59:6: warning: symbol 'jent_zalloc' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:64:6: warning: symbol 'jent_zfree' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:69:5: warning: symbol 'jent_fips_enabled' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:74:6: warning: symbol 'jent_panic' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:79:6: warning: symbol 'jent_memcpy' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:93:6: warning: symbol 'jent_get_nstime' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reviewed-by: Stephan Mueller <smueller@chronox.de Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-10-09 12:12:56 +03:00
extern void *jent_zalloc(unsigned int len);
extern void jent_zfree(void *ptr);
extern void jent_get_nstime(__u64 *out);
crypto: jitter - replace LFSR with SHA3-256 Using the kernel crypto API, the SHA3-256 algorithm is used as conditioning element to replace the LFSR in the Jitter RNG. All other parts of the Jitter RNG are unchanged. The application and use of the SHA-3 conditioning operation is identical to the user space Jitter RNG 3.4.0 by applying the following concept: - the Jitter RNG initializes a SHA-3 state which acts as the "entropy pool" when the Jitter RNG is allocated. - When a new time delta is obtained, it is inserted into the "entropy pool" with a SHA-3 update operation. Note, this operation in most of the cases is a simple memcpy() onto the SHA-3 stack. - To cause a true SHA-3 operation for each time delta operation, a second SHA-3 operation is performed hashing Jitter RNG status information. The final message digest is also inserted into the "entropy pool" with a SHA-3 update operation. Yet, this data is not considered to provide any entropy, but it shall stir the entropy pool. - To generate a random number, a SHA-3 final operation is performed to calculate a message digest followed by an immediate SHA-3 init to re-initialize the "entropy pool". The obtained message digest is one block of the Jitter RNG that is returned to the caller. Mathematically speaking, the random number generated by the Jitter RNG is: aux_t = SHA-3(Jitter RNG state data) Jitter RNG block = SHA-3(time_i || aux_i || time_(i-1) || aux_(i-1) || ... || time_(i-255) || aux_(i-255)) when assuming that the OSR = 1, i.e. the default value. This operation implies that the Jitter RNG has an output-blocksize of 256 bits instead of the 64 bits of the LFSR-based Jitter RNG that is replaced with this patch. The patch also replaces the varying number of invocations of the conditioning function with one fixed number of invocations. The use of the conditioning function consistent with the userspace Jitter RNG library version 3.4.0. The code is tested with a system that exhibited the least amount of entropy generated by the Jitter RNG: the SiFive Unmatched RISC-V system. The measured entropy rate is well above the heuristically implied entropy value of 1 bit of entropy per time delta. On all other tested systems, the measured entropy rate is even higher by orders of magnitude. The measurement was performed using updated tooling provided with the user space Jitter RNG library test framework. The performance of the Jitter RNG with this patch is about en par with the performance of the Jitter RNG without the patch. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-04-21 09:08:04 +03:00
extern int jent_hash_time(void *hash_state, __u64 time, u8 *addtl,
unsigned int addtl_len, __u64 hash_loop_cnt,
unsigned int stuck);
int jent_read_random_block(void *hash_state, char *dst, unsigned int dst_len);
crypto: jitter - add header to fix buildwarnings Fix the following build warnings by adding a header for the definitions shared between jitterentropy.c and jitterentropy-kcapi.c. Fixes the following: crypto/jitterentropy.c:445:5: warning: symbol 'jent_read_entropy' was not declared. Should it be static? crypto/jitterentropy.c:475:18: warning: symbol 'jent_entropy_collector_alloc' was not declared. Should it be static? crypto/jitterentropy.c:509:6: warning: symbol 'jent_entropy_collector_free' was not declared. Should it be static? crypto/jitterentropy.c:516:5: warning: symbol 'jent_entropy_init' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:59:6: warning: symbol 'jent_zalloc' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:64:6: warning: symbol 'jent_zfree' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:69:5: warning: symbol 'jent_fips_enabled' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:74:6: warning: symbol 'jent_panic' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:79:6: warning: symbol 'jent_memcpy' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:93:6: warning: symbol 'jent_get_nstime' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reviewed-by: Stephan Mueller <smueller@chronox.de Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-10-09 12:12:56 +03:00
struct rand_data;
crypto: jitter - add RCT/APT support for different OSRs The oversampling rate (OSR) value specifies the heuristically implied entropy in the recorded data - H_submitter = 1/osr. A different entropy estimate implies a different APT/RCT cutoff value. This change adds support for OSRs 1 through 15. This OSR can be selected by the caller of the Jitter RNG. For this patch, the caller still uses one hard-coded OSR. A subsequent patch allows this value to be configured. In addition, the power-up self test is adjusted as follows: * It allows the caller to provide an oversampling rate that should be tested with - commonly it should be the same as used for the actual runtime operation. This makes the power-up testing therefore consistent with the runtime operation. * It calls now jent_measure_jitter (i.e. collects the full entropy that can possibly be harvested by the Jitter RNG) instead of only jent_condition_data (which only returns the entropy harvested from the conditioning component). This should now alleviate reports where the Jitter RNG initialization thinks there is too little entropy. * The power-up test now solely relies on the (enhanced) APT and RCT test that is used as a health test at runtime. The code allowing the different OSRs as well as the power-up test changes are present in the user space version of the Jitter RNG 3.4.1 and thus was already in production use for some time. Reported-by "Ospan, Abylay" <aospan@amazon.com> Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-09-21 14:48:11 +03:00
extern int jent_entropy_init(unsigned int osr, unsigned int flags,
crypto: jitter - reuse allocated entropy collector In case a health test error occurs during runtime, the power-up health tests are rerun to verify that the noise source is still good and that the reported health test error was an outlier. For performing this power-up health test, the already existing entropy collector instance is used instead of allocating a new one. This change has the following implications: * The noise that is collected as part of the newly run health tests is inserted into the entropy collector and thus stirs the existing data present in there further. Thus, the entropy collected during the health test is not wasted. This is also allowed by SP800-90B. * The power-on health test is not affected by the state of the entropy collector, because it resets the APT / RCT state. The remainder of the state is unrelated to the health test as it is only applied to newly obtained time stamps. This change also fixes a bug report about an allocation while in an atomic lock (the lock is taken in jent_kcapi_random, jent_read_entropy is called and this can call jent_entropy_init). Fixes: 04597c8dd6c4 ("jitter - add RCT/APT support for different OSRs") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-10-07 10:10:43 +03:00
void *hash_state, struct rand_data *p_ec);
crypto: jitter - add header to fix buildwarnings Fix the following build warnings by adding a header for the definitions shared between jitterentropy.c and jitterentropy-kcapi.c. Fixes the following: crypto/jitterentropy.c:445:5: warning: symbol 'jent_read_entropy' was not declared. Should it be static? crypto/jitterentropy.c:475:18: warning: symbol 'jent_entropy_collector_alloc' was not declared. Should it be static? crypto/jitterentropy.c:509:6: warning: symbol 'jent_entropy_collector_free' was not declared. Should it be static? crypto/jitterentropy.c:516:5: warning: symbol 'jent_entropy_init' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:59:6: warning: symbol 'jent_zalloc' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:64:6: warning: symbol 'jent_zfree' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:69:5: warning: symbol 'jent_fips_enabled' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:74:6: warning: symbol 'jent_panic' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:79:6: warning: symbol 'jent_memcpy' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:93:6: warning: symbol 'jent_get_nstime' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reviewed-by: Stephan Mueller <smueller@chronox.de Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-10-09 12:12:56 +03:00
extern int jent_read_entropy(struct rand_data *ec, unsigned char *data,
unsigned int len);
extern struct rand_data *jent_entropy_collector_alloc(unsigned int osr,
crypto: jitter - replace LFSR with SHA3-256 Using the kernel crypto API, the SHA3-256 algorithm is used as conditioning element to replace the LFSR in the Jitter RNG. All other parts of the Jitter RNG are unchanged. The application and use of the SHA-3 conditioning operation is identical to the user space Jitter RNG 3.4.0 by applying the following concept: - the Jitter RNG initializes a SHA-3 state which acts as the "entropy pool" when the Jitter RNG is allocated. - When a new time delta is obtained, it is inserted into the "entropy pool" with a SHA-3 update operation. Note, this operation in most of the cases is a simple memcpy() onto the SHA-3 stack. - To cause a true SHA-3 operation for each time delta operation, a second SHA-3 operation is performed hashing Jitter RNG status information. The final message digest is also inserted into the "entropy pool" with a SHA-3 update operation. Yet, this data is not considered to provide any entropy, but it shall stir the entropy pool. - To generate a random number, a SHA-3 final operation is performed to calculate a message digest followed by an immediate SHA-3 init to re-initialize the "entropy pool". The obtained message digest is one block of the Jitter RNG that is returned to the caller. Mathematically speaking, the random number generated by the Jitter RNG is: aux_t = SHA-3(Jitter RNG state data) Jitter RNG block = SHA-3(time_i || aux_i || time_(i-1) || aux_(i-1) || ... || time_(i-255) || aux_(i-255)) when assuming that the OSR = 1, i.e. the default value. This operation implies that the Jitter RNG has an output-blocksize of 256 bits instead of the 64 bits of the LFSR-based Jitter RNG that is replaced with this patch. The patch also replaces the varying number of invocations of the conditioning function with one fixed number of invocations. The use of the conditioning function consistent with the userspace Jitter RNG library version 3.4.0. The code is tested with a system that exhibited the least amount of entropy generated by the Jitter RNG: the SiFive Unmatched RISC-V system. The measured entropy rate is well above the heuristically implied entropy value of 1 bit of entropy per time delta. On all other tested systems, the measured entropy rate is even higher by orders of magnitude. The measurement was performed using updated tooling provided with the user space Jitter RNG library test framework. The performance of the Jitter RNG with this patch is about en par with the performance of the Jitter RNG without the patch. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-04-21 09:08:04 +03:00
unsigned int flags,
void *hash_state);
crypto: jitter - add header to fix buildwarnings Fix the following build warnings by adding a header for the definitions shared between jitterentropy.c and jitterentropy-kcapi.c. Fixes the following: crypto/jitterentropy.c:445:5: warning: symbol 'jent_read_entropy' was not declared. Should it be static? crypto/jitterentropy.c:475:18: warning: symbol 'jent_entropy_collector_alloc' was not declared. Should it be static? crypto/jitterentropy.c:509:6: warning: symbol 'jent_entropy_collector_free' was not declared. Should it be static? crypto/jitterentropy.c:516:5: warning: symbol 'jent_entropy_init' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:59:6: warning: symbol 'jent_zalloc' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:64:6: warning: symbol 'jent_zfree' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:69:5: warning: symbol 'jent_fips_enabled' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:74:6: warning: symbol 'jent_panic' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:79:6: warning: symbol 'jent_memcpy' was not declared. Should it be static? crypto/jitterentropy-kcapi.c:93:6: warning: symbol 'jent_get_nstime' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reviewed-by: Stephan Mueller <smueller@chronox.de Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-10-09 12:12:56 +03:00
extern void jent_entropy_collector_free(struct rand_data *entropy_collector);
crypto: jitter - add interface for gathering of raw entropy The test interface allows a privileged process to capture the raw unconditioned noise that is collected by the Jitter RNG for statistical analysis. Such testing allows the analysis how much entropy the Jitter RNG noise source provides on a given platform. The obtained data is the time stamp sampled by the Jitter RNG. Considering that the Jitter RNG inserts the delta of this time stamp compared to the immediately preceding time stamp, the obtained data needs to be post-processed accordingly to obtain the data the Jitter RNG inserts into its entropy pool. The raw entropy collection is provided to obtain the raw unmodified time stamps that are about to be added to the Jitter RNG entropy pool and are credited with entropy. Thus, this patch adds an interface which renders the Jitter RNG insecure. This patch is NOT INTENDED FOR PRODUCTION SYSTEMS, but solely for development/test systems to verify the available entropy rate. Access to the data is given through the jent_raw_hires debugfs file. The data buffer should be multiples of sizeof(u32) to fill the entire buffer. Using the option jitterentropy_testing.boot_raw_hires_test=1 the raw noise of the first 1000 entropy events since boot can be sampled. This test interface allows generating the data required for analysis whether the Jitter RNG is in compliance with SP800-90B sections 3.1.3 and 3.1.4. If the test interface is not compiled, its code is a noop which has no impact on the performance. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-04-21 09:08:23 +03:00
#ifdef CONFIG_CRYPTO_JITTERENTROPY_TESTINTERFACE
int jent_raw_hires_entropy_store(__u32 value);
void jent_testing_init(void);
void jent_testing_exit(void);
#else /* CONFIG_CRYPTO_JITTERENTROPY_TESTINTERFACE */
static inline int jent_raw_hires_entropy_store(__u32 value) { return 0; }
static inline void jent_testing_init(void) { }
static inline void jent_testing_exit(void) { }
#endif /* CONFIG_CRYPTO_JITTERENTROPY_TESTINTERFACE */
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