1/*
2 * Copyright (C) 2009 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "config.h"
32#include "platform/fonts/opentype/OpenTypeSanitizer.h"
33
34#include "platform/RuntimeEnabledFeatures.h"
35#include "platform/SharedBuffer.h"
36#include "opentype-sanitiser.h"
37#include "ots-memory-stream.h"
38
39namespace blink {
40
41PassRefPtr<SharedBuffer> OpenTypeSanitizer::sanitize()
42{
43    if (!m_buffer)
44        return nullptr;
45
46    // This is the largest web font size which we'll try to transcode.
47    static const size_t maxWebFontSize = 30 * 1024 * 1024; // 30 MB
48    if (m_buffer->size() > maxWebFontSize)
49        return nullptr;
50
51    if (RuntimeEnabledFeatures::woff2Enabled())
52        ots::EnableWOFF2();
53
54    // A transcoded font is usually smaller than an original font.
55    // However, it can be slightly bigger than the original one due to
56    // name table replacement and/or padding for glyf table.
57    //
58    // With WOFF fonts, however, we'll be decompressing, so the result can be
59    // much larger than the original.
60
61    ots::ExpandingMemoryStream output(m_buffer->size(), maxWebFontSize);
62    if (!ots::Process(&output, reinterpret_cast<const uint8_t*>(m_buffer->data()), m_buffer->size()))
63        return nullptr;
64
65    const size_t transcodeLen = output.Tell();
66    return SharedBuffer::create(static_cast<unsigned char*>(output.get()), transcodeLen);
67}
68
69bool OpenTypeSanitizer::supportsFormat(const String& format)
70{
71    return equalIgnoringCase(format, "woff")
72        || (RuntimeEnabledFeatures::woff2Enabled() && equalIgnoringCase(format, "woff2"));
73}
74
75} // namespace blink
76