Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright 2025 Google LLC */
3
4#include <test_progs.h>
5#include "bpf/libbpf_internal.h"
6
7#define MAX_LEN 4096
8
9/* Test libbpf_sha256() for all lengths from 0 to MAX_LEN inclusively. */
10void test_sha256(void)
11{
12 /*
13 * The correctness of this value was verified by running this test with
14 * libbpf_sha256() replaced by OpenSSL's SHA256().
15 */
16 static const __u8 expected_digest_of_digests[SHA256_DIGEST_LENGTH] = {
17 0x62, 0x30, 0x0e, 0x1d, 0xea, 0x7f, 0xc4, 0x74,
18 0xfd, 0x8e, 0x64, 0x0b, 0xd8, 0x5f, 0xea, 0x04,
19 0xf3, 0xef, 0x77, 0x42, 0xc2, 0x01, 0xb8, 0x90,
20 0x6e, 0x19, 0x91, 0x1b, 0xca, 0xb3, 0x28, 0x42,
21 };
22 __u64 seed = 0;
23 __u8 *data = NULL, *digests = NULL;
24 __u8 digest_of_digests[SHA256_DIGEST_LENGTH];
25 size_t i;
26
27 data = malloc(MAX_LEN);
28 if (!ASSERT_OK_PTR(data, "malloc"))
29 goto out;
30 digests = malloc((MAX_LEN + 1) * SHA256_DIGEST_LENGTH);
31 if (!ASSERT_OK_PTR(digests, "malloc"))
32 goto out;
33
34 /* Generate MAX_LEN bytes of "random" data deterministically. */
35 for (i = 0; i < MAX_LEN; i++) {
36 seed = (seed * 25214903917 + 11) & ((1ULL << 48) - 1);
37 data[i] = (__u8)(seed >> 16);
38 }
39
40 /* Calculate a digest for each length 0 through MAX_LEN inclusively. */
41 for (i = 0; i <= MAX_LEN; i++)
42 libbpf_sha256(data, i, &digests[i * SHA256_DIGEST_LENGTH]);
43
44 /* Calculate and verify the digest of all the digests. */
45 libbpf_sha256(digests, (MAX_LEN + 1) * SHA256_DIGEST_LENGTH,
46 digest_of_digests);
47 ASSERT_MEMEQ(digest_of_digests, expected_digest_of_digests,
48 SHA256_DIGEST_LENGTH, "digest_of_digests");
49out:
50 free(data);
51 free(digests);
52}