1/*
2 * Copyright (C) 2009 Apple 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
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "CanvasRenderingContext.h"
28
29#include "CachedImage.h"
30#include "CanvasPattern.h"
31#include "HTMLCanvasElement.h"
32#include "HTMLImageElement.h"
33#include "HTMLVideoElement.h"
34#include "Image.h"
35#include "ImageBitmap.h"
36#include "OffscreenCanvas.h"
37#include "SecurityOrigin.h"
38#include <wtf/HashSet.h>
39#include <wtf/IsoMallocInlines.h>
40#include <wtf/Lock.h>
41#include <wtf/NeverDestroyed.h>
42#include <wtf/URL.h>
43
44namespace WebCore {
45
46WTF_MAKE_ISO_ALLOCATED_IMPL(CanvasRenderingContext);
47
48HashSet<CanvasRenderingContext*>& CanvasRenderingContext::instances(const LockHolder&)
49{
50 static NeverDestroyed<HashSet<CanvasRenderingContext*>> instances;
51 return instances;
52}
53
54Lock& CanvasRenderingContext::instancesMutex()
55{
56 static LazyNeverDestroyed<Lock> mutex;
57 static std::once_flag initializeMutex;
58 std::call_once(initializeMutex, [] {
59 mutex.construct();
60 });
61 return mutex.get();
62}
63
64CanvasRenderingContext::CanvasRenderingContext(CanvasBase& canvas)
65 : m_canvas(canvas)
66{
67 LockHolder lock(instancesMutex());
68 instances(lock).add(this);
69}
70
71CanvasRenderingContext::~CanvasRenderingContext()
72{
73 LockHolder lock(instancesMutex());
74 ASSERT(instances(lock).contains(this));
75 instances(lock).remove(this);
76}
77
78void CanvasRenderingContext::ref()
79{
80 m_canvas.refCanvasBase();
81}
82
83void CanvasRenderingContext::deref()
84{
85 m_canvas.derefCanvasBase();
86}
87
88bool CanvasRenderingContext::wouldTaintOrigin(const CanvasPattern* pattern)
89{
90 if (m_canvas.originClean() && pattern && !pattern->originClean())
91 return true;
92 return false;
93}
94
95bool CanvasRenderingContext::wouldTaintOrigin(const CanvasBase* sourceCanvas)
96{
97 if (m_canvas.originClean() && sourceCanvas && !sourceCanvas->originClean())
98 return true;
99 return false;
100}
101
102bool CanvasRenderingContext::wouldTaintOrigin(const HTMLImageElement* element)
103{
104 if (!element || !m_canvas.originClean())
105 return false;
106
107 auto* cachedImage = element->cachedImage();
108 if (!cachedImage)
109 return false;
110
111 auto image = makeRefPtr(cachedImage->image());
112 if (!image)
113 return false;
114
115 if (image->sourceURL().protocolIsData())
116 return false;
117
118 if (!image->hasSingleSecurityOrigin())
119 return true;
120
121 if (!cachedImage->isCORSSameOrigin())
122 return true;
123
124 ASSERT(m_canvas.securityOrigin());
125 ASSERT(cachedImage->origin());
126 ASSERT(m_canvas.securityOrigin()->toString() == cachedImage->origin()->toString());
127 return false;
128}
129
130bool CanvasRenderingContext::wouldTaintOrigin(const HTMLVideoElement* video)
131{
132#if ENABLE(VIDEO)
133 // FIXME: This check is likely wrong when a redirect is involved. We need
134 // to test the finalURL. Please be careful when fixing this issue not to
135 // make currentSrc be the final URL because then the
136 // HTMLMediaElement.currentSrc DOM API would leak redirect destinations!
137 if (!video || !m_canvas.originClean())
138 return false;
139
140 if (!video->hasSingleSecurityOrigin())
141 return true;
142
143 if (!(video->player() && video->player()->didPassCORSAccessCheck()) && video->wouldTaintOrigin(*m_canvas.securityOrigin()))
144 return true;
145
146#else
147 UNUSED_PARAM(video);
148#endif
149
150 return false;
151}
152
153bool CanvasRenderingContext::wouldTaintOrigin(const ImageBitmap* imageBitmap)
154{
155 if (!imageBitmap || !m_canvas.originClean())
156 return false;
157
158 return !imageBitmap->originClean();
159}
160
161bool CanvasRenderingContext::wouldTaintOrigin(const URL& url)
162{
163 if (!m_canvas.originClean())
164 return false;
165
166 if (url.protocolIsData())
167 return false;
168
169 return !m_canvas.securityOrigin()->canRequest(url);
170}
171
172void CanvasRenderingContext::checkOrigin(const URL& url)
173{
174 if (wouldTaintOrigin(url))
175 m_canvas.setOriginTainted();
176}
177
178void CanvasRenderingContext::checkOrigin(const TypedOMCSSImageValue&)
179{
180 m_canvas.setOriginTainted();
181}
182
183} // namespace WebCore
184