Parts of the LFSR are already covered by self-tests, including: * Self-test of SP800-90A DRBG provided by the Linux kernel crypto API. * Self-test of the PRNG provided by the Linux kernel crypto API. * Raw noise source data testing including SP800-90B compliant tests when enabling CONFIG_LRNG_HEALTH_TESTS This patch adds the self-tests for the remaining critical functions of the LRNG that are essential to maintain entropy and provide cryptographic strong random numbers. The following self-tests are implemented: * Self-test of the time array maintenance. This test verifies whether the time stamp array management to store multiple values in one integer implements a concatenation of the data. * Self-test of the LFSR operation. This test injects a monotonic increasing counter into the LFSR. After completion of the injection of the counter, 3 pool words are compared with known good values. The known good values are calculated with the newly-developed tool lfsr_testvector_generation provided as part of the LRNG test tool set at [1]. * Self-test of the Hash_DF operation ensures that this function operates compliant to the specification. The self-test performs a Hash_DF operation of a zeroized entropy pool state. The test vectors are generated using the newly-developed tool hash_df_testvector_generation provided as part of the LRNG test tool set at [1]. * Self-test of the ChaCha20 DRNG is based on the self-tests that are already present and implemented with the stand-alone user space ChaCha20 DRNG implementation available at [2]. The self-tests cover different use cases of the DRNG seeded with known seed data. The status of the LRNG self-tests is provided with the selftest_status SysFS file. If the file contains a zero, the self-tests passed. The value 0xffffffff means that the self-tests were not executed. Any other value indicates a self-test failure. The self-test may be compiled to panic the system if the self-test fails. All self-tests operate on private state data structures. This implies that none of the self-tests have any impact on the regular LRNG operations. This allows the self-tests to be repeated at runtime by writing anything into the selftest_status SysFS file. [1] https://www.chronox.de/lrng.html [2] https://www.chronox.de/chacha20.html CC: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> CC: "Alexander E. Patrakov" <patrakov@xxxxxxxxx> CC: "Ahmed S. Darwish" <darwish.07@xxxxxxxxx> CC: "Theodore Y. Ts'o" <tytso@xxxxxxx> CC: Willy Tarreau <w@xxxxxx> CC: Matthew Garrett <mjg59@xxxxxxxxxxxxx> CC: Vito Caputo <vcaputo@xxxxxxxxxxx> CC: Andreas Dilger <adilger.kernel@xxxxxxxxx> CC: Jan Kara <jack@xxxxxxx> CC: Ray Strode <rstrode@xxxxxxxxxx> CC: William Jon McCann <mccann@xxxxxxx> CC: zhangjs <zachary@xxxxxxxxxxxxxxxx> CC: Andy Lutomirski <luto@xxxxxxxxxx> CC: Florian Weimer <fweimer@xxxxxxxxxx> CC: Lennart Poettering <mzxreary@xxxxxxxxxxx> CC: Nicolai Stange <nstange@xxxxxxx> CC: Marcelo Henrique Cerri <marcelo.cerri@xxxxxxxxxxxxx> CC: Neil Horman <nhorman@xxxxxxxxxx> Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx> --- drivers/char/lrng/Kconfig | 25 ++ drivers/char/lrng/Makefile | 1 + drivers/char/lrng/lrng_selftest.c | 418 ++++++++++++++++++++++++++++++ 3 files changed, 444 insertions(+) create mode 100644 drivers/char/lrng/lrng_selftest.c diff --git a/drivers/char/lrng/Kconfig b/drivers/char/lrng/Kconfig index e503a4bb7475..0c9ad9563fb7 100644 --- a/drivers/char/lrng/Kconfig +++ b/drivers/char/lrng/Kconfig @@ -175,4 +175,29 @@ config LRNG_TESTING If unsure, say N. +config LRNG_SELFTEST + bool "Enable power-on and on-demand self-tests" + help + The power-on self-tests are executed during boot time + covering the ChaCha20 DRNG, the LFSR processing and the + time stamp management of the LRNG. + + The on-demand self-tests are triggered by writing any + value into the SysFS file selftest_status. At the same + time, when reading this file, the test status is + returned. A zero indicates that all tests were executed + successfully. + + If unsure, say Y. + +if LRNG_SELFTEST + +config LRNG_SELFTEST_PANIC + bool "Panic the kernel upon self-test failure" + help + If the option is enabled, the kernel is terminated if an + LRNG power-on self-test failure is detected. + +endif # LRNG_SELFTEST + endif # LRNG diff --git a/drivers/char/lrng/Makefile b/drivers/char/lrng/Makefile index b2ce1979dc4b..92219c565f66 100644 --- a/drivers/char/lrng/Makefile +++ b/drivers/char/lrng/Makefile @@ -16,3 +16,4 @@ obj-$(CONFIG_LRNG_KCAPI) += lrng_kcapi.o obj-$(CONFIG_LRNG_JENT) += lrng_jent.o obj-$(CONFIG_LRNG_HEALTH_TESTS) += lrng_health.o obj-$(CONFIG_LRNG_TESTING) += lrng_testing.o +obj-$(CONFIG_LRNG_SELFTEST) += lrng_selftest.o diff --git a/drivers/char/lrng/lrng_selftest.c b/drivers/char/lrng/lrng_selftest.c new file mode 100644 index 000000000000..da213572e1dd --- /dev/null +++ b/drivers/char/lrng/lrng_selftest.c @@ -0,0 +1,418 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause +/* + * LRNG power-on and on-demand self-test + * + * Copyright (C) 2016 - 2020, Stephan Mueller <smueller@xxxxxxxxxx> + */ + +/* + * In addition to the self-tests below, the following LRNG components + * are covered with self-tests during regular operation: + * + * * power-on self-test: SP800-90A DRBG provided by the Linux kernel crypto API + * * power-on self-test: PRNG provided by the Linux kernel crypto API + * * runtime test: Raw noise source data testing including SP800-90B compliant + * tests when enabling CONFIG_LRNG_HEALTH_TESTS + * + * Additional developer tests present with LRNG code: + * * SP800-90B APT and RCT test enforcement validation when enabling + * CONFIG_LRNG_APT_BROKEN or CONFIG_LRNG_RCT_BROKEN. + * * Collection of raw entropy from the interrupt noise source when enabling + * CONFIG_LRNG_TESTING and pulling the data from the kernel with the provided + * interface. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/lrng.h> +#include <linux/slab.h> + +#include "lrng_chacha20.h" +#include "lrng_internal.h" +#include "lrng_lfsr.h" +#include "lrng_sw_noise.h" + +#define LRNG_SELFTEST_PASSED 0 +#define LRNG_SEFLTEST_ERROR_TIME (1 << 0) +#define LRNG_SEFLTEST_ERROR_LFSR (1 << 1) +#define LRNG_SEFLTEST_ERROR_CHACHA20 (1 << 2) +#define LRNG_SEFLTEST_ERROR_HASHDF (1 << 3) +#define LRNG_SELFTEST_NOT_EXECUTED 0xffffffff + +static u32 lrng_time_selftest[LRNG_TIME_ARRAY_SIZE]; + +static unsigned int lrng_selftest_status = LRNG_SELFTEST_NOT_EXECUTED; + +static inline void lrng_time_process_selftest_insert(u32 time) +{ + static u32 lrng_time_selftest_ptr = 0; + u32 ptr = lrng_time_selftest_ptr++ & LRNG_TIME_WORD_MASK; + + lrng_time_selftest[lrng_time_idx2array(ptr)] |= + lrng_time_slot_val(time & LRNG_TIME_SLOTSIZE_MASK, + lrng_time_idx2slot(ptr)); +} + +static unsigned int lrng_time_process_selftest(void) +{ + u32 time; + u32 idx_zero_compare = (0 << 0) | (1 << 8) | (2 << 16) | (3 << 24); + u32 idx_one_compare = (4 << 0) | (5 << 8) | (6 << 16) | (7 << 24); + u32 idx_last_compare = ((LRNG_TIME_NUM_VALUES - 4) << 0) | + ((LRNG_TIME_NUM_VALUES - 3) << 8) | + ((LRNG_TIME_NUM_VALUES - 2) << 16) | + ((LRNG_TIME_NUM_VALUES - 1) << 24); + + (void)idx_one_compare; + + for (time = 0; time < LRNG_TIME_NUM_VALUES; time++) + lrng_time_process_selftest_insert(time); + + if ((lrng_time_selftest[0] != idx_zero_compare) || +#if (LRNG_TIME_ARRAY_SIZE > 1) + (lrng_time_selftest[1] != idx_one_compare) || +#endif + (lrng_time_selftest[LRNG_TIME_ARRAY_SIZE - 1] != idx_last_compare)) + { + pr_err("LRNG time array self-test FAILED\n"); + return LRNG_SEFLTEST_ERROR_TIME; + } + + return LRNG_SELFTEST_PASSED; +} + +/* + * The test vectors are generated with the lfsr_testvector_generation tool + * provided as part of the test tool set of the LRNG. + */ +static unsigned int lrng_pool_lfsr_selftest(void) +{ + /* + * First, 67th and last entry of entropy pool. + * + * The 67th entry is picked because this one is the first to receive + * an entry. As we start with 1 to inject into the LFSR, the + * 67th entry should be equal to rol(1, 7) >> 3 considering that + * all other values of the LFSR are zero and the the twist value of 0 + * is applied. + */ + static u32 const lrng_lfsr_selftest_result[][3] = { + { 0xf56df24a, 0x00000010, 0x0e014939 }, + { 0x4b130726, 0x00000010, 0x2802f509 }, + { 0x87279152, 0x00000010, 0x00150000 }, + { 0x0b67f997, 0x00000010, 0x00150000 }, + { 0x4fea174f, 0x00000010, 0xcbf4a6ae }, + { 0x77149108, 0x00000010, 0x77bfadf2 }, + { 0x1e96037e, 0x00000010, 0x18017e79 }, + { 0xc84acef2, 0x00000010, 0x6345f7a8 }, + { 0x6a2eb6df, 0x00000010, 0x03950000 }, + }; + struct lrng_pool *lrng_pool, *lrng_pool_aligned; + u32 i, ret = LRNG_SELFTEST_PASSED; + + BUILD_BUG_ON(ARRAY_SIZE(lrng_lfsr_selftest_result) < + CONFIG_LRNG_POOL_SIZE); + + lrng_pool = kzalloc(sizeof(struct lrng_pool) + LRNG_KCAPI_ALIGN, + GFP_KERNEL); + if (!lrng_pool) + return LRNG_SEFLTEST_ERROR_LFSR; + lrng_pool_aligned = PTR_ALIGN(lrng_pool, sizeof(u32)); + + for (i = 1; i <= LRNG_POOL_SIZE; i++) + _lrng_pool_lfsr_u32(lrng_pool_aligned, i); + + if ((atomic_read_u32(&lrng_pool_aligned->pool[0]) != + lrng_lfsr_selftest_result[CONFIG_LRNG_POOL_SIZE][0]) || + (atomic_read_u32(&lrng_pool_aligned->pool[67 & + (LRNG_POOL_SIZE - 1)]) != + lrng_lfsr_selftest_result[CONFIG_LRNG_POOL_SIZE][1]) || + (atomic_read_u32(&lrng_pool_aligned->pool[LRNG_POOL_SIZE - 1]) != + lrng_lfsr_selftest_result[CONFIG_LRNG_POOL_SIZE][2])) { + pr_err("LRNG LFSR self-test FAILED\n"); + ret = LRNG_SEFLTEST_ERROR_LFSR; + } + + kfree(lrng_pool); + return ret; +} + +/* + * The test vectors are generated with the hash_df_testvector_generation tool + * provided as part of the test tool set of the LRNG. + */ +static unsigned int lrng_hash_df_selftest(void) +{ + const struct lrng_crypto_cb *crypto_cb = &lrng_cc20_crypto_cb; + + /* + * The size of 45 bytes is chosen arbitrarily. Yet, this size should + * ensure that we have at least two hash blocks plus some fraction + * of a hash block generated. + */ + static u8 const lrng_hash_df_selftest_result[][45] = { + { + 0x3b, 0xbe, 0x7a, 0xbd, 0x2b, 0x16, 0x02, 0x4c, + 0xfc, 0xd3, 0x02, 0x15, 0xf0, 0x86, 0xd4, 0xdb, + 0x49, 0xec, 0x26, 0x53, 0xd6, 0xc9, 0x6d, 0xad, + 0x24, 0xca, 0x72, 0x89, 0x2c, 0xfa, 0x48, 0x18, + 0xf7, 0x47, 0xb5, 0x2f, 0x92, 0xa2, 0x1b, 0xd9, + 0x24, 0xa7, 0x2f, 0xa2, 0x0b, + }, { + 0xd2, 0xaa, 0xf9, 0x76, 0x26, 0xc6, 0x13, 0xea, + 0xb8, 0xde, 0xe6, 0x88, 0x8f, 0xc4, 0x7a, 0x7d, + 0x9c, 0xb4, 0x1b, 0xd1, 0xd1, 0x8a, 0x40, 0xc9, + 0xaa, 0x45, 0xa6, 0xb6, 0xb5, 0x6f, 0xf6, 0xbc, + 0xbb, 0x77, 0x37, 0xbc, 0x5a, 0x2d, 0xcc, 0x84, + 0x25, 0x68, 0x5e, 0xba, 0x16, + }, { + 0x58, 0x66, 0x82, 0x88, 0x29, 0x19, 0xa4, 0xbb, + 0x33, 0x42, 0xc9, 0x72, 0x0d, 0x68, 0x6e, 0xb9, + 0xc6, 0xe0, 0x7a, 0xf9, 0x20, 0xca, 0x6d, 0x18, + 0x35, 0xec, 0xfa, 0x9e, 0xf6, 0x3a, 0xa7, 0xb6, + 0x92, 0x7a, 0xe5, 0xcd, 0xc5, 0x13, 0x9f, 0x65, + 0x6a, 0xe1, 0xe4, 0x3f, 0xb9, + }, { + 0xdd, 0xf1, 0x34, 0xca, 0x08, 0xe3, 0xce, 0x8a, + 0x26, 0x6b, 0xce, 0x99, 0x8a, 0x84, 0xd2, 0x21, + 0x98, 0x10, 0x95, 0x5f, 0x9f, 0xc3, 0xf2, 0xe4, + 0x79, 0x75, 0xb5, 0x15, 0xa7, 0xa2, 0xf1, 0xc4, + 0xdc, 0x67, 0xcb, 0x67, 0x8c, 0xb2, 0x1b, 0xd5, + 0xd6, 0x8b, 0xc2, 0x34, 0xd6, + }, { + 0xc3, 0x16, 0x9d, 0xf0, 0x78, 0x15, 0xab, 0xf2, + 0x2f, 0xc9, 0x2e, 0xe1, 0xc6, 0x5e, 0xfa, 0x03, + 0xaf, 0xd4, 0xd5, 0x47, 0x2a, 0xe8, 0x06, 0xe8, + 0x7e, 0x0a, 0x71, 0xc7, 0x0d, 0x39, 0xb1, 0xa9, + 0x5a, 0x49, 0xee, 0x8b, 0x2f, 0xcd, 0xea, 0x96, + 0xcc, 0x08, 0x71, 0xef, 0x9c, + }, { + 0x1a, 0x3d, 0x70, 0x39, 0xc2, 0x02, 0x4d, 0x3a, + 0xaa, 0x14, 0x20, 0x88, 0x96, 0x4c, 0x7c, 0xe4, + 0xaa, 0x49, 0x89, 0x30, 0x50, 0x96, 0xb6, 0xa7, + 0x55, 0x0a, 0xf8, 0xd2, 0x4e, 0x83, 0x9d, 0x1f, + 0x56, 0x49, 0x13, 0xc6, 0x46, 0x55, 0x73, 0x0d, + 0x74, 0xcd, 0x81, 0xe0, 0x65, + }, { + 0x4b, 0xf6, 0x49, 0x89, 0x2a, 0x9f, 0x67, 0xd7, + 0xb8, 0x1d, 0xbb, 0x5d, 0xf0, 0x1b, 0x60, 0xb6, + 0xb7, 0xf3, 0x86, 0x6d, 0xe0, 0x04, 0xa1, 0xbc, + 0x3b, 0xb0, 0x10, 0x91, 0xe8, 0x22, 0x67, 0x5b, + 0xe8, 0xf0, 0x4f, 0x82, 0x70, 0xc7, 0xe1, 0xc8, + 0xd8, 0xad, 0x70, 0xcf, 0xf6, + }, { + 0x60, 0x1f, 0x71, 0x07, 0x92, 0xae, 0xa0, 0x24, + 0xb6, 0xa4, 0x10, 0x70, 0x1f, 0x94, 0x51, 0x9a, + 0x5a, 0x81, 0xc4, 0x46, 0x78, 0x56, 0x71, 0xdd, + 0x45, 0x63, 0x01, 0x34, 0x87, 0x79, 0xb4, 0xd5, + 0x91, 0x79, 0xb9, 0x93, 0x11, 0x44, 0x50, 0xad, + 0x64, 0x7e, 0x5c, 0xec, 0x16, + }, { + 0x49, 0x2f, 0xa0, 0x45, 0xf8, 0xb0, 0x80, 0x88, + 0x79, 0xeb, 0xb6, 0x82, 0x1c, 0xf3, 0x67, 0xc4, + 0x88, 0x88, 0xe9, 0x75, 0x20, 0x54, 0x78, 0xc6, + 0x5c, 0x59, 0xcf, 0xd9, 0x73, 0x12, 0x17, 0xf4, + 0x30, 0x9c, 0xb7, 0x21, 0x45, 0xe2, 0xb6, 0x0c, + 0x0c, 0xeb, 0x1b, 0xdc, 0xdc, + } + }; + struct lrng_pool *lrng_pool, *lrng_pool_aligned; + u8 hash_df[sizeof(lrng_hash_df_selftest_result[0])] + __aligned(sizeof(u32)); + u32 generated; + int ret = 0; + + BUILD_BUG_ON(ARRAY_SIZE(lrng_hash_df_selftest_result) < + CONFIG_LRNG_POOL_SIZE); + + lrng_pool = kzalloc(sizeof(struct lrng_pool) + LRNG_KCAPI_ALIGN, + GFP_KERNEL); + if (!lrng_pool) + return LRNG_SEFLTEST_ERROR_HASHDF; + lrng_pool_aligned = PTR_ALIGN(lrng_pool, sizeof(u32)); + + generated = __lrng_pool_hash_df(crypto_cb, NULL, lrng_pool_aligned, + hash_df, sizeof(hash_df) << 3); + + if ((generated >> 3) != sizeof(hash_df) || + memcmp(hash_df, lrng_hash_df_selftest_result[CONFIG_LRNG_POOL_SIZE], + sizeof(hash_df))) { + pr_err("LRNG Hash DF self-test FAILED\n"); + ret = LRNG_SEFLTEST_ERROR_HASHDF; + } + + kfree(lrng_pool); + return ret; +} + +/* + * The test vectors were generated using the ChaCha20 DRNG from + * https://www.chronox.de/chacha20.html + */ +static unsigned int lrng_chacha20_drng_selftest(void) +{ + const struct lrng_crypto_cb *crypto_cb = &lrng_cc20_crypto_cb; + static u8 const seed[CHACHA_KEY_SIZE * 2] = { + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, + 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, + 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, + 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, + }; + struct chacha20_block chacha20; + int ret; + u8 outbuf[CHACHA_KEY_SIZE * 2] __aligned(sizeof(u32)); + + /* + * Expected result when ChaCha20 DRNG state is zero: + * * constants are set to "expand 32-byte k" + * * remaining state is 0 + * and pulling one half ChaCha20 DRNG block. + */ + static u8 const expected_halfblock[CHACHA_KEY_SIZE] = { + 0x76, 0xb8, 0xe0, 0xad, 0xa0, 0xf1, 0x3d, 0x90, + 0x40, 0x5d, 0x6a, 0xe5, 0x53, 0x86, 0xbd, 0x28, + 0xbd, 0xd2, 0x19, 0xb8, 0xa0, 0x8d, 0xed, 0x1a, + 0xa8, 0x36, 0xef, 0xcc, 0x8b, 0x77, 0x0d, 0xc7 }; + + /* + * Expected result when ChaCha20 DRNG state is zero: + * * constants are set to "expand 32-byte k" + * * remaining state is 0 + * followed by a reseed with two keyblocks + * 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + * 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + * 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + * 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, + * 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, + * 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, + * 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, + * 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f + * and pulling one ChaCha20 DRNG block. + */ + static u8 const expected_oneblock[CHACHA_KEY_SIZE * 2] = { + 0xf5, 0xb4, 0xb6, 0x5a, 0xec, 0xcd, 0x5a, 0x65, + 0x87, 0x56, 0xe3, 0x86, 0x51, 0x54, 0xfc, 0x90, + 0x56, 0xff, 0x5e, 0xae, 0x58, 0xf2, 0x01, 0x88, + 0xb1, 0x7e, 0xb8, 0x2e, 0x17, 0x9a, 0x27, 0xe6, + 0x86, 0xb3, 0xed, 0x33, 0xf7, 0xb9, 0x06, 0x05, + 0x8a, 0x2d, 0x1a, 0x93, 0xc9, 0x0b, 0x80, 0x04, + 0x03, 0xaa, 0x60, 0xaf, 0xd5, 0x36, 0x40, 0x11, + 0x67, 0x89, 0xb1, 0x66, 0xd5, 0x88, 0x62, 0x6d }; + + /* + * Expected result when ChaCha20 DRNG state is zero: + * * constants are set to "expand 32-byte k" + * * remaining state is 0 + * followed by a reseed with one key block plus one byte + * 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + * 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + * 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + * 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, + * 0x20 + * and pulling less than one ChaCha20 DRNG block. + */ + static u8 const expected_block_nonalinged[CHACHA_KEY_SIZE + 1] = { + 0x3d, 0x13, 0x47, 0x1e, 0x7f, 0x7c, 0x99, 0x33, + 0xfc, 0x44, 0xa4, 0xdd, 0xf9, 0x3d, 0xe1, 0x9a, + 0xd4, 0xe8, 0x7a, 0x7d, 0x42, 0xac, 0xd1, 0xcd, + 0x10, 0x69, 0xe7, 0xbf, 0xd4, 0xfd, 0x69, 0x4b, + 0xa7 }; + + memset(&chacha20, 0, sizeof(chacha20)); + lrng_cc20_init_rfc7539(&chacha20); + + /* Generate with zero state */ + ret = crypto_cb->lrng_drng_generate_helper(&chacha20, outbuf, + sizeof(expected_halfblock)); + if (ret != sizeof(expected_halfblock)) + goto err; + if (memcmp(outbuf, expected_halfblock, sizeof(expected_halfblock))) + goto err; + + /* Clear state of DRNG */ + memset(&chacha20.key.u[0], 0, 48); + + /* Reseed with 2 key blocks */ + ret = crypto_cb->lrng_drng_seed_helper(&chacha20, seed, + sizeof(expected_oneblock)); + if (ret < 0) + goto err; + ret = crypto_cb->lrng_drng_generate_helper(&chacha20, outbuf, + sizeof(expected_oneblock)); + if (ret != sizeof(expected_oneblock)) + goto err; + if (memcmp(outbuf, expected_oneblock, sizeof(expected_oneblock))) + goto err; + + /* Clear state of DRNG */ + memset(&chacha20.key.u[0], 0, 48); + + /* Reseed with 1 key block and one byte */ + ret = crypto_cb->lrng_drng_seed_helper(&chacha20, seed, + sizeof(expected_block_nonalinged)); + if (ret < 0) + goto err; + ret = crypto_cb->lrng_drng_generate_helper(&chacha20, outbuf, + sizeof(expected_block_nonalinged)); + if (ret != sizeof(expected_block_nonalinged)) + goto err; + if (memcmp(outbuf, expected_block_nonalinged, + sizeof(expected_block_nonalinged))) + goto err; + + return LRNG_SELFTEST_PASSED; + +err: + pr_err("LRNG ChaCha20 DRNG self-test FAILED\n"); + return LRNG_SEFLTEST_ERROR_CHACHA20; +} + +static int lrng_selftest(void) +{ + unsigned int ret = lrng_time_process_selftest(); + + ret |= lrng_pool_lfsr_selftest(); + ret |= lrng_chacha20_drng_selftest(); + ret |= lrng_hash_df_selftest(); + + if (ret) { + if (IS_ENABLED(CONFIG_LRNG_SELFTEST_PANIC)) + panic("LRNG self-tests failed: %u\n", ret); + } else { + pr_info("LRNG self-tests passed\n"); + } + + lrng_selftest_status = ret; + + if (lrng_selftest_status) + return -EFAULT; + return 0; +} + +#ifdef CONFIG_SYSFS +/* Re-perform self-test when any value is written to the sysfs file. */ +static int lrng_selftest_sysfs_set(const char *val, + const struct kernel_param *kp) +{ + return lrng_selftest(); +} + +static const struct kernel_param_ops lrng_selftest_sysfs = { + .set = lrng_selftest_sysfs_set, + .get = param_get_uint, +}; +module_param_cb(selftest_status, &lrng_selftest_sysfs, &lrng_selftest_status, + 0644); +#endif /* CONFIG_SYSFS */ + +static int __init lrng_selftest_init(void) +{ + return lrng_selftest(); +} + +module_init(lrng_selftest_init); -- 2.24.1
