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| 1 | +// Copyright 2025 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 <algorithm> |
| 6 | +#include <cstdint> |
| 7 | +#include <cstring> |
| 8 | +#include <vector> |
| 9 | + |
| 10 | +#include "unzip.h" |
| 11 | + |
| 12 | +// Fuzzer builds often have NDEBUG set, so roll our own assert macro. |
| 13 | +#define ASSERT(cond) \ |
| 14 | + do { \ |
| 15 | + if (!(cond)) { \ |
| 16 | + fprintf(stderr, "%s:%d Assert failed: %s\n", __FILE__, __LINE__, #cond); \ |
| 17 | + exit(1); \ |
| 18 | + } \ |
| 19 | + } while (0) |
| 20 | + |
| 21 | +extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) { |
| 22 | + // Mock read-only filesystem with only one file, file_data. In the calls |
| 23 | + // below, 'opaque' points to file_data, and 'strm' points to the file's seek |
| 24 | + // position, which is heap allocated so that failing to "close" it triggers a |
| 25 | + // leak error. |
| 26 | + std::vector<uint8_t> file_data(data, data + size); |
| 27 | + zlib_filefunc64_def file_func = { |
| 28 | + .zopen64_file = [](void* opaque, const void* filename, |
| 29 | + int mode) -> void* { |
| 30 | + ASSERT(mode == (ZLIB_FILEFUNC_MODE_READ | ZLIB_FILEFUNC_MODE_EXISTING)); |
| 31 | + return new size_t(0); |
| 32 | + }, |
| 33 | + .zread_file = [](void* opaque, void* strm, void* buf, |
| 34 | + uLong size) -> uLong { |
| 35 | + std::vector<uint8_t>* vec = static_cast<std::vector<uint8_t>*>(opaque); |
| 36 | + size_t* pos = static_cast<size_t*>(strm); |
| 37 | + if (*pos >= vec->size()) { |
| 38 | + return 0; |
| 39 | + } |
| 40 | + size = std::min(static_cast<size_t>(size), vec->size() - *pos); |
| 41 | + memcpy(buf, vec->data() + *pos, size); |
| 42 | + (*pos) += size; |
| 43 | + return size; |
| 44 | + }, |
| 45 | + .zwrite_file = [](void*, void*, const void*, uLong) -> uLong { |
| 46 | + ASSERT(0 && "Writing is not supported."); |
| 47 | + return 0; |
| 48 | + }, |
| 49 | + .ztell64_file = [](void*, void* strm) -> ZPOS64_T { |
| 50 | + return *static_cast<size_t*>(strm); |
| 51 | + }, |
| 52 | + .zseek64_file = [](void* opaque, void* strm, ZPOS64_T offset, |
| 53 | + int origin) -> long { |
| 54 | + std::vector<uint8_t>* vec = static_cast<std::vector<uint8_t>*>(opaque); |
| 55 | + size_t* pos = static_cast<size_t*>(strm); |
| 56 | + switch (origin) { |
| 57 | + case ZLIB_FILEFUNC_SEEK_SET: |
| 58 | + *pos = offset; |
| 59 | + break; |
| 60 | + case ZLIB_FILEFUNC_SEEK_CUR: |
| 61 | + *pos = *pos + offset; |
| 62 | + break; |
| 63 | + case ZLIB_FILEFUNC_SEEK_END: |
| 64 | + *pos = vec->size() + offset; |
| 65 | + break; |
| 66 | + default: |
| 67 | + ASSERT(0 && "Invalid origin"); |
| 68 | + } |
| 69 | + return 0; |
| 70 | + }, |
| 71 | + .zclose_file = [](void*, void* strm) -> int { |
| 72 | + delete static_cast<size_t*>(strm); |
| 73 | + return 0; |
| 74 | + }, |
| 75 | + .zerror_file = [](void*, void*) -> int { return 0; }, |
| 76 | + .opaque = &file_data}; |
| 77 | + |
| 78 | + unzFile uzf = unzOpen2_64("foo.zip", &file_func); |
| 79 | + if (uzf == NULL) { |
| 80 | + return 0; |
| 81 | + } |
| 82 | + |
| 83 | + while (true) { |
| 84 | + unz_file_info64 info = {0}; |
| 85 | + |
| 86 | + // TODO: Pass nullptrs and different buffer sizes to cover more code. |
| 87 | + char filename[UINT16_MAX + 1]; // +1 for the null terminator. |
| 88 | + char extra[UINT16_MAX]; // No null terminator. |
| 89 | + char comment[UINT16_MAX + 1]; // +1 for the null terminator. |
| 90 | + |
| 91 | + if (unzGetCurrentFileInfo64(uzf, &info, filename, sizeof(filename), extra, |
| 92 | + sizeof(extra), comment, sizeof(comment)) == UNZ_OK) { |
| 93 | + ASSERT(info.size_filename <= UINT16_MAX); |
| 94 | + ASSERT(info.size_file_extra <= UINT16_MAX); |
| 95 | + ASSERT(info.size_file_comment <= UINT16_MAX); |
| 96 | + |
| 97 | + ASSERT(filename[info.size_filename] == '\0'); |
| 98 | + ASSERT(comment[info.size_file_comment] == '\0'); |
| 99 | + } |
| 100 | + |
| 101 | + if (unzOpenCurrentFile(uzf) == UNZ_OK) { |
| 102 | + while (true) { |
| 103 | + char buffer[4096]; |
| 104 | + int num_read = unzReadCurrentFile(uzf, buffer, sizeof(buffer)); |
| 105 | + if (num_read <= 0) { |
| 106 | + break; |
| 107 | + } |
| 108 | + } |
| 109 | + unzCloseCurrentFile(uzf); |
| 110 | + } |
| 111 | + |
| 112 | + if (unzGoToNextFile(uzf) != UNZ_OK) { |
| 113 | + break; |
| 114 | + } |
| 115 | + } |
| 116 | + |
| 117 | + unzClose(uzf); |
| 118 | + return 0; |
| 119 | +} |
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