/*

 * libgit2 commit-graph fuzzer target.

 *

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#include <stdio.h>

#include "git2.h"

#include "common.h"

#include "str.h"

#include "futils.h"

#include "hash.h"

#include "commit_graph.h"

#include "standalone_driver.h"

int LLVMFuzzerInitialize(int *argc, char ***argv)

{

  GIT_UNUSED(argc);

  GIT_UNUSED(argv);

  if (git_libgit2_init() < 0) {

    fprintf(stderr, "Failed to initialize libgit2\n");

    abort();

  }

  return 0;

}

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)

{

  git_commit_graph_file file = {{0}};

  git_commit_graph_entry e;

  git_str commit_graph_buf = GIT_STR_INIT;

  unsigned char hash[GIT_HASH_SHA1_SIZE];

  git_oid oid = GIT_OID_NONE;

  bool append_hash = false;

  if (size < 4)

    return 0;

  /*

   * If the first byte in the stream has the high bit set, append the

   * SHA1 hash so that the file is somewhat valid.

   */

  append_hash = *data & 0x80;

  /* Keep a 4-byte alignment to avoid unaligned accesses. */

  data += 4;

  size -= 4;

  if (append_hash) {

    if (git_str_init(&commit_graph_buf, size + GIT_HASH_SHA1_SIZE) < 0)

      goto cleanup;

    if (git_hash_buf(hash, data, size, GIT_HASH_ALGORITHM_SHA1) < 0) {

      fprintf(stderr, "Failed to compute the SHA1 hash\n");

      abort();

    }

    memcpy(commit_graph_buf.ptr, data, size);

    memcpy(commit_graph_buf.ptr + size, hash, GIT_HASH_SHA1_SIZE);

    memcpy(oid.id, hash, GIT_OID_SHA1_SIZE);

  } else {

    git_str_attach_notowned(&commit_graph_buf, (char *)data, size);

  }

  if (git_commit_graph_file_parse(

          &file,

          (const unsigned char *)git_str_cstr(&commit_graph_buf),

          git_str_len(&commit_graph_buf))

      < 0)

    goto cleanup;

  /* Search for any oid, just to exercise that codepath. */

  if (git_commit_graph_entry_find(&e, &file, &oid, GIT_OID_SHA1_HEXSIZE) < 0)

    goto cleanup;

cleanup:

  git_commit_graph_file_close(&file);

  git_str_dispose(&commit_graph_buf);

  return 0;

}