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Diffstat (limited to 'lib/crypto/tests/ghash_kunit.c')
| -rw-r--r-- | lib/crypto/tests/ghash_kunit.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/lib/crypto/tests/ghash_kunit.c b/lib/crypto/tests/ghash_kunit.c new file mode 100644 index 000000000000..68b3837a3607 --- /dev/null +++ b/lib/crypto/tests/ghash_kunit.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2026 Google LLC + */ +#include <crypto/gf128hash.h> +#include "ghash-testvecs.h" + +/* + * A fixed key used when presenting GHASH as an unkeyed hash function in order + * to reuse hash-test-template.h. At the beginning of the test suite, this is + * initialized to a key prepared from bytes generated from a fixed seed. + */ +static struct ghash_key test_key; + +static void ghash_init_withtestkey(struct ghash_ctx *ctx) +{ + ghash_init(ctx, &test_key); +} + +static void ghash_withtestkey(const u8 *data, size_t len, + u8 out[GHASH_BLOCK_SIZE]) +{ + ghash(&test_key, data, len, out); +} + +/* Generate the HASH_KUNIT_CASES using hash-test-template.h. */ +#define HASH ghash_withtestkey +#define HASH_CTX ghash_ctx +#define HASH_SIZE GHASH_BLOCK_SIZE +#define HASH_INIT ghash_init_withtestkey +#define HASH_UPDATE ghash_update +#define HASH_FINAL ghash_final +#include "hash-test-template.h" + +/* + * Test a key and messages containing all one bits. This is useful to detect + * overflow bugs in implementations that emulate carryless multiplication using + * a series of standard multiplications with the bits spread out. + */ +static void test_ghash_allones_key_and_message(struct kunit *test) +{ + struct ghash_key key; + struct ghash_ctx hashofhashes_ctx; + u8 hash[GHASH_BLOCK_SIZE]; + + static_assert(TEST_BUF_LEN >= 4096); + memset(test_buf, 0xff, 4096); + + ghash_preparekey(&key, test_buf); + ghash_init(&hashofhashes_ctx, &key); + for (size_t len = 0; len <= 4096; len += 16) { + ghash(&key, test_buf, len, hash); + ghash_update(&hashofhashes_ctx, hash, sizeof(hash)); + } + ghash_final(&hashofhashes_ctx, hash); + KUNIT_ASSERT_MEMEQ(test, hash, ghash_allones_hashofhashes, + sizeof(hash)); +} + +#define MAX_LEN_FOR_KEY_CHECK 1024 + +/* + * Given two prepared keys which should be identical (but may differ in + * alignment and/or whether they are followed by a guard page or not), verify + * that they produce consistent results on various data lengths. + */ +static void check_key_consistency(struct kunit *test, + const struct ghash_key *key1, + const struct ghash_key *key2) +{ + u8 *data = test_buf; + u8 hash1[GHASH_BLOCK_SIZE]; + u8 hash2[GHASH_BLOCK_SIZE]; + + rand_bytes(data, MAX_LEN_FOR_KEY_CHECK); + KUNIT_ASSERT_MEMEQ(test, key1, key2, sizeof(*key1)); + + for (int i = 0; i < 100; i++) { + size_t len = rand_length(MAX_LEN_FOR_KEY_CHECK); + + ghash(key1, data, len, hash1); + ghash(key2, data, len, hash2); + KUNIT_ASSERT_MEMEQ(test, hash1, hash2, sizeof(hash1)); + } +} + +/* Test that no buffer overreads occur on either raw_key or ghash_key. */ +static void test_ghash_with_guarded_key(struct kunit *test) +{ + u8 raw_key[GHASH_BLOCK_SIZE]; + u8 *guarded_raw_key = &test_buf[TEST_BUF_LEN - sizeof(raw_key)]; + struct ghash_key key1, key2; + struct ghash_key *guarded_key = + (struct ghash_key *)&test_buf[TEST_BUF_LEN - sizeof(key1)]; + + /* Prepare with regular buffers. */ + rand_bytes(raw_key, sizeof(raw_key)); + ghash_preparekey(&key1, raw_key); + + /* Prepare with guarded raw_key, then check that it works. */ + memcpy(guarded_raw_key, raw_key, sizeof(raw_key)); + ghash_preparekey(&key2, guarded_raw_key); + check_key_consistency(test, &key1, &key2); + + /* Prepare guarded ghash_key, then check that it works. */ + ghash_preparekey(guarded_key, raw_key); + check_key_consistency(test, &key1, guarded_key); +} + +/* + * Test that ghash_key only needs to be aligned to + * __alignof__(struct ghash_key), i.e. 8 bytes. The assembly code may prefer + * 16-byte or higher alignment, but it mustn't require it. + */ +static void test_ghash_with_minimally_aligned_key(struct kunit *test) +{ + u8 raw_key[GHASH_BLOCK_SIZE]; + struct ghash_key key; + struct ghash_key *minaligned_key = + (struct ghash_key *)&test_buf[MAX_LEN_FOR_KEY_CHECK + + __alignof__(struct ghash_key)]; + + KUNIT_ASSERT_TRUE(test, IS_ALIGNED((uintptr_t)minaligned_key, + __alignof__(struct ghash_key))); + KUNIT_ASSERT_TRUE(test, !IS_ALIGNED((uintptr_t)minaligned_key, + 2 * __alignof__(struct ghash_key))); + + rand_bytes(raw_key, sizeof(raw_key)); + ghash_preparekey(&key, raw_key); + ghash_preparekey(minaligned_key, raw_key); + check_key_consistency(test, &key, minaligned_key); +} + +struct ghash_irq_test_state { + struct ghash_key expected_key; + u8 raw_key[GHASH_BLOCK_SIZE]; +}; + +static bool ghash_irq_test_func(void *state_) +{ + struct ghash_irq_test_state *state = state_; + struct ghash_key key; + + ghash_preparekey(&key, state->raw_key); + return memcmp(&key, &state->expected_key, sizeof(key)) == 0; +} + +/* + * Test that ghash_preparekey() produces the same output regardless of whether + * FPU or vector registers are usable when it is called. + */ +static void test_ghash_preparekey_in_irqs(struct kunit *test) +{ + struct ghash_irq_test_state state; + + rand_bytes(state.raw_key, sizeof(state.raw_key)); + ghash_preparekey(&state.expected_key, state.raw_key); + kunit_run_irq_test(test, ghash_irq_test_func, 200000, &state); +} + +static int ghash_suite_init(struct kunit_suite *suite) +{ + u8 raw_key[GHASH_BLOCK_SIZE]; + + rand_bytes_seeded_from_len(raw_key, sizeof(raw_key)); + ghash_preparekey(&test_key, raw_key); + return hash_suite_init(suite); +} + +static void ghash_suite_exit(struct kunit_suite *suite) +{ + hash_suite_exit(suite); +} + +static struct kunit_case ghash_test_cases[] = { + HASH_KUNIT_CASES, + KUNIT_CASE(test_ghash_allones_key_and_message), + KUNIT_CASE(test_ghash_with_guarded_key), + KUNIT_CASE(test_ghash_with_minimally_aligned_key), + KUNIT_CASE(test_ghash_preparekey_in_irqs), + KUNIT_CASE(benchmark_hash), + {}, +}; + +static struct kunit_suite ghash_test_suite = { + .name = "ghash", + .test_cases = ghash_test_cases, + .suite_init = ghash_suite_init, + .suite_exit = ghash_suite_exit, +}; +kunit_test_suite(ghash_test_suite); + +MODULE_DESCRIPTION("KUnit tests and benchmark for GHASH"); +MODULE_LICENSE("GPL"); |