mirror of https://github.com/google/oss-fuzz.git
124 lines
3.3 KiB
C++
124 lines
3.3 KiB
C++
// Copyright 2015 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include <stddef.h>
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#include <stdint.h>
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#include <vector>
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#define PNG_INTERNAL
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#include "png.h"
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struct BufState {
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const uint8_t* data;
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size_t bytes_left;
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};
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struct PngObjectHandler {
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png_infop info_ptr = nullptr;
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png_structp png_ptr = nullptr;
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png_voidp row_ptr = nullptr;
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BufState* buf_state = nullptr;
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~PngObjectHandler() {
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if (row_ptr && png_ptr) {
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png_free(png_ptr, row_ptr);
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}
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if (png_ptr && info_ptr) {
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png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
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}
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delete buf_state;
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}
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};
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void user_read_data(png_structp png_ptr, png_bytep data, png_size_t length) {
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BufState* buf_state = static_cast<BufState*>(png_get_io_ptr(png_ptr));
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if (length > buf_state->bytes_left) {
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png_error(png_ptr, "read error");
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}
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memcpy(data, buf_state->data, length);
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buf_state->bytes_left -= length;
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buf_state->data += length;
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}
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static const int kPngHeaderSize = 8;
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// Entry point for LibFuzzer.
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// Roughly follows the libpng book example:
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// http://www.libpng.org/pub/png/book/chapter13.html
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extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
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if (size < kPngHeaderSize) {
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return 0;
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}
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std::vector<unsigned char> v(data, data + size);
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if (png_sig_cmp(v.data(), 0, kPngHeaderSize)) {
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// not a PNG.
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return 0;
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}
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PngObjectHandler png_handler;
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png_handler.png_ptr = png_create_read_struct
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(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
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if (!png_handler.png_ptr) {
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return 0;
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}
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png_set_crc_action(png_handler.png_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
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png_handler.info_ptr = png_create_info_struct(png_handler.png_ptr);
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if (!png_handler.info_ptr) {
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return 0;
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}
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// Setting up reading from buffer.
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png_handler.buf_state = new BufState();
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png_handler.buf_state->data = data + kPngHeaderSize;
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png_handler.buf_state->bytes_left = size - kPngHeaderSize;
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png_set_read_fn(png_handler.png_ptr, png_handler.buf_state, user_read_data);
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png_set_sig_bytes(png_handler.png_ptr, kPngHeaderSize);
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// libpng error handling.
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if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
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return 0;
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}
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// Reading.
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png_read_info(png_handler.png_ptr, png_handler.info_ptr);
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png_handler.row_ptr = png_malloc(
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png_handler.png_ptr, png_get_rowbytes(png_handler.png_ptr,
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png_handler.info_ptr));
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// reset error handler to put png_deleter into scope.
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if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
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return 0;
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}
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png_uint_32 width, height;
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int bit_depth, color_type, interlace_type, compression_type;
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int filter_type;
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if (!png_get_IHDR(png_handler.png_ptr, png_handler.info_ptr, &width,
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&height, &bit_depth, &color_type, &interlace_type,
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&compression_type, &filter_type)) {
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return 0;
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}
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// This is going to be too slow.
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if (width && height > 100000000 / width)
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return 0;
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int passes = png_set_interlace_handling(png_handler.png_ptr);
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png_start_read_image(png_handler.png_ptr);
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for (int pass = 0; pass < passes; ++pass) {
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for (png_uint_32 y = 0; y < height; ++y) {
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png_read_row(png_handler.png_ptr,
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static_cast<png_bytep>(png_handler.row_ptr), NULL);
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}
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}
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return 0;
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}
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