thodg/libgit2/fuzzers/packfile_fuzzer.c

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• Hash : 3c966fb4
  Author :
  Date : 2019-06-28T10:53:03
  

  fuzzers: clean up header includes
  
  There's multiple headers included in our fuzzers that aren't required at
  all. Furthermore, some of them are not available on Win32, causing
  builds to fail. Remove them to fix this.
  

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• fuzzers/packfile_fuzzer.c

• /*
   * libgit2 packfile 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 "git2/sys/mempack.h"
  #include "common.h"
  #include "buffer.h"
  
  static git_odb *odb = NULL;
  static git_odb_backend *mempack = NULL;
  
  /* Arbitrary object to seed the ODB. */
  static const unsigned char base_obj[] = { 07, 076 };
  static const unsigned int base_obj_len = 2;
  
  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();
  	}
  	if (git_libgit2_opts(GIT_OPT_SET_PACK_MAX_OBJECTS, 10000000) < 0) {
  		fprintf(stderr, "Failed to limit maximum pack object count\n");
  		abort();
  	}
  	if (git_odb_new(&odb) < 0) {
  		fprintf(stderr, "Failed to create the odb\n");
  		abort();
  	}
  	if (git_mempack_new(&mempack) < 0) {
  		fprintf(stderr, "Failed to create the mempack\n");
  		abort();
  	}
  	if (git_odb_add_backend(odb, mempack, 999) < 0) {
  		fprintf(stderr, "Failed to add the mempack\n");
  		abort();
  	}
  	return 0;
  }
  
  int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
  {
  	git_indexer_progress stats = {0, 0};
  	git_indexer *indexer = NULL;
  	git_buf path = GIT_BUF_INIT;
  	git_oid oid;
  	bool append_hash = false;
  
  	if (size == 0)
  		return 0;
  
  	if (!odb || !mempack) {
  		fprintf(stderr, "Global state not initialized\n");
  		abort();
  	}
  	git_mempack_reset(mempack);
  
  	if (git_odb_write(&oid, odb, base_obj, base_obj_len, GIT_OBJECT_BLOB) < 0) {
  		fprintf(stderr, "Failed to add an object to the odb\n");
  		abort();
  	}
  
  	if (git_indexer_new(&indexer, ".", 0, odb, NULL) < 0) {
  		fprintf(stderr, "Failed to create the indexer: %s\n",
  			git_error_last()->message);
  		abort();
  	}
  
  	/*
  	 * If the first byte in the stream has the high bit set, append the
  	 * SHA1 hash so that the packfile is somewhat valid.
  	 */
  	append_hash = *data & 0x80;
  	++data;
  	--size;
  
  	if (git_indexer_append(indexer, data, size, &stats) < 0)
  		goto cleanup;
  	if (append_hash) {
  		if (git_odb_hash(&oid, data, size, GIT_OBJECT_BLOB) < 0) {
  			fprintf(stderr, "Failed to compute the SHA1 hash\n");
  			abort();
  		}
  		if (git_indexer_append(indexer, &oid, sizeof(oid), &stats) < 0) {
  			goto cleanup;
  		}
  	}
  	if (git_indexer_commit(indexer, &stats) < 0)
  		goto cleanup;
  
  	if (git_buf_printf(&path, "pack-%s.idx", git_oid_tostr_s(git_indexer_hash(indexer))) < 0)
  		goto cleanup;
  	p_unlink(git_buf_cstr(&path));
  
  	git_buf_clear(&path);
  
  	if (git_buf_printf(&path, "pack-%s.pack", git_oid_tostr_s(git_indexer_hash(indexer))) < 0)
  		goto cleanup;
  	p_unlink(git_buf_cstr(&path));
  
  cleanup:
  	git_mempack_reset(mempack);
  	git_indexer_free(indexer);
  	git_buf_dispose(&path);
  	return 0;
  }
  

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