fuzz_json.c

/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* tests/fuzzing/fuzz_json.c */
/*
 * Copyright (C) 2024 by Arjun. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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 */

/*
 * Fuzzing harness implementation for k5_json_decode.
 */

#include "autoconf.h"
#include <k5-int.h>
#include <krb5.h>
#include <k5-json.h>
#include <string.h>

#define kMinInputLength 2
#define kMaxInputLength 1024

extern int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);

int
LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
{
    krb5_error_code ret;
    k5_json_value decoded = NULL;
    char *data_in = NULL, *data_out;

    if (size < kMinInputLength || size > kMaxInputLength)
        return 0;

    data_in = k5memdup0(data, size, &ret);
    if (data_in == NULL)
        return 0;

    ret = k5_json_decode(data_in, &decoded);
    if (ret)
        goto cleanup;

    ret = k5_json_encode(decoded, &data_out);
    if (!ret)
        free(data_out);

cleanup:
    free(data_in);
    k5_json_release(decoded);

    return 0;
}