// SPDX-License-Identifier: GPL-2.0
#include "tests.h"
#include "util/blake2s.h"
#include "util/debug.h"

#include <linux/compiler.h>
#include <stdlib.h>
#include <string2.h>

static int test_strreplace(char needle, const char *haystack,
                           const char *replace, const char *expected)
{
        char *new = strreplace_chars(needle, haystack, replace);
        int ret = strcmp(new, expected);

        free(new);
        return ret == 0;
}

/* Maximum data length tested by test_blake2s() */
#define MAX_DATA_LEN 512

/*
 * Hash length tested by test_blake2s().  BLAKE2s supports variable-length
 * hashes.  However, the only user of BLAKE2s in 'perf' uses 20-byte hashes,
 * matching the length of the ELF build ID field.  So that's the length we test.
 */
#define HASH_LEN 20

/* Test the implementation of the BLAKE2s hash algorithm. */
static int test_blake2s(void)
{
        u8 data[MAX_DATA_LEN];
        u8 hash[HASH_LEN];
        u8 hash2[HASH_LEN];
        struct blake2s_ctx main_ctx;
        /*
         * This value was generated by the following Python code:
         *
         * import hashlib
         *
         * data = bytes(i % 256 for i in range(513))
         * h = hashlib.blake2s(digest_size=20)
         * for i in range(513):
         *     h.update(hashlib.blake2s(data=data[:i], digest_size=20).digest())
         * print(h.hexdigest())
         */
        static const u8 expected_hash_of_hashes[20] = {
                0xef, 0x9b, 0x13, 0x98, 0x78, 0x8e, 0x74, 0x59, 0x9c, 0xd5,
                0x0c, 0xf0, 0x33, 0x97, 0x79, 0x3d, 0x3e, 0xd0, 0x95, 0xa6
        };
        size_t i;

        /* Generate MAX_DATA_LEN bytes of data. */
        for (i = 0; i < MAX_DATA_LEN; i++)
                data[i] = i;

        blake2s_init(&main_ctx, sizeof(hash));
        for (i = 0; i <= MAX_DATA_LEN; i++) {
                struct blake2s_ctx ctx;

                /* Compute the BLAKE2s hash of 'i' data bytes. */
                blake2s_init(&ctx, HASH_LEN);
                blake2s_update(&ctx, data, i);
                blake2s_final(&ctx, hash);

                /* Verify that multiple updates produce the same result. */
                blake2s_init(&ctx, HASH_LEN);
                blake2s_update(&ctx, data, i / 2);
                blake2s_update(&ctx, &data[i / 2], i - (i / 2));
                blake2s_final(&ctx, hash2);
                TEST_ASSERT_VAL("inconsistent BLAKE2s hashes",
                                memcmp(hash, hash2, HASH_LEN) == 0);

                /*
                 * Pass the hash to another BLAKE2s context, so that we
                 * incrementally compute the hash of all the hashes.
                 */
                blake2s_update(&main_ctx, hash, HASH_LEN);
        }

        /* Verify the hash of all the hashes. */
        blake2s_final(&main_ctx, hash);
        TEST_ASSERT_VAL("wrong BLAKE2s hashes",
                        memcmp(hash, expected_hash_of_hashes, HASH_LEN) == 0);
        return 0;
}

static int test__util(struct test_suite *t __maybe_unused, int subtest __maybe_unused)
{
        TEST_ASSERT_VAL("empty string", test_strreplace(' ', "", "123", ""));
        TEST_ASSERT_VAL("no match", test_strreplace('5', "123", "4", "123"));
        TEST_ASSERT_VAL("replace 1", test_strreplace('3', "123", "4", "124"));
        TEST_ASSERT_VAL("replace 2", test_strreplace('a', "abcabc", "ef", "efbcefbc"));
        TEST_ASSERT_VAL("replace long", test_strreplace('a', "abcabc", "longlong",
                                                        "longlongbclonglongbc"));

        return test_blake2s();
}

DEFINE_SUITE("util", util);