1 // Copyright 2017 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include <fuzzer/FuzzedDataProvider.h>
6 #include <stddef.h>
7 #include <stdint.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <string.h>
11 #include <vector>
12
13 #include "zlib.h"
14
15 // Fuzzer builds often have NDEBUG set, so roll our own assert macro.
16 #define ASSERT(cond) \
17 do { \
18 if (!(cond)) { \
19 fprintf(stderr, "%s:%d Assert failed: %s\n", __FILE__, __LINE__, #cond); \
20 exit(1); \
21 } \
22 } while (0)
23
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)24 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
25 FuzzedDataProvider fdp(data, size);
26 int level = fdp.PickValueInArray({0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
27 int windowBits = fdp.PickValueInArray({9, 10, 11, 12, 13, 14, 15});
28 int memLevel = fdp.PickValueInArray({1, 2, 3, 4, 5, 6, 7, 8, 9});
29 int strategy = fdp.PickValueInArray(
30 {Z_DEFAULT_STRATEGY, Z_FILTERED, Z_HUFFMAN_ONLY, Z_RLE, Z_FIXED});
31 std::vector<uint8_t> src = fdp.ConsumeRemainingBytes<uint8_t>();
32
33 z_stream stream;
34 stream.zalloc = Z_NULL;
35 stream.zfree = Z_NULL;
36
37 // Compress the data one byte at a time to exercise the streaming code.
38 int ret =
39 deflateInit2(&stream, level, Z_DEFLATED, windowBits, memLevel, strategy);
40 ASSERT(ret == Z_OK);
41 std::vector<uint8_t> compressed(src.size() * 2 + 1000);
42 stream.next_out = compressed.data();
43 stream.avail_out = compressed.size();
44 for (uint8_t b : src) {
45 stream.next_in = &b;
46 stream.avail_in = 1;
47 ret = deflate(&stream, Z_NO_FLUSH);
48 ASSERT(ret == Z_OK);
49 }
50 stream.next_in = Z_NULL;
51 stream.avail_in = 0;
52 ret = deflate(&stream, Z_FINISH);
53 ASSERT(ret == Z_STREAM_END);
54 compressed.resize(compressed.size() - stream.avail_out);
55 deflateEnd(&stream);
56
57 // Verify that the data decompresses correctly.
58 ret = inflateInit2(&stream, windowBits);
59 ASSERT(ret == Z_OK);
60 // Make room for at least one byte so it's never empty.
61 std::vector<uint8_t> decompressed(src.size() + 1);
62 stream.next_in = compressed.data();
63 stream.avail_in = compressed.size();
64 stream.next_out = decompressed.data();
65 stream.avail_out = decompressed.size();
66 ret = inflate(&stream, Z_FINISH);
67 ASSERT(ret == Z_STREAM_END);
68 decompressed.resize(decompressed.size() - stream.avail_out);
69 inflateEnd(&stream);
70
71 ASSERT(decompressed == src);
72
73 return 0;
74 }
75