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/*
* Copyright (C) 2015 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "DataURLDecoder.h"
#include "HTTPParsers.h"
#include "ParsedContentType.h"
#include <pal/text/DecodeEscapeSequences.h>
#include <pal/text/TextEncoding.h>
#include <wtf/MainThread.h>
#include <wtf/RunLoop.h>
#include <wtf/URL.h>
#include <wtf/WorkQueue.h>
#include <wtf/text/Base64.h>
#if PLATFORM(COCOA)
#include <wtf/cocoa/RuntimeApplicationChecksCocoa.h>
#endif
namespace WebCore {
namespace DataURLDecoder {
static bool shouldRemoveFragmentIdentifier(const String& mediaType)
{
#if PLATFORM(COCOA)
if (!linkedOnOrAfterSDKWithBehavior(SDKAlignedBehavior::DataURLFragmentRemoval))
return false;
// HLS uses # in the middle of the manifests.
return !equalLettersIgnoringASCIICase(mediaType, "video/mpegurl"_s)
&& !equalLettersIgnoringASCIICase(mediaType, "audio/mpegurl"_s)
&& !equalLettersIgnoringASCIICase(mediaType, "application/x-mpegurl"_s)
&& !equalLettersIgnoringASCIICase(mediaType, "vnd.apple.mpegurl"_s);
#else
UNUSED_PARAM(mediaType);
return true;
#endif
}
static WorkQueue& decodeQueue()
{
static auto& queue = WorkQueue::create("org.webkit.DataURLDecoder", WorkQueue::QOS::UserInitiated).leakRef();
return queue;
}
static Result parseMediaType(const String& mediaType)
{
if (std::optional<ParsedContentType> parsedContentType = ParsedContentType::create(mediaType))
return { parsedContentType->mimeType(), parsedContentType->charset(), parsedContentType->serialize(), { } };
return { "text/plain"_s, "US-ASCII"_s, "text/plain;charset=US-ASCII"_s, { } };
}
struct DecodeTask {
WTF_MAKE_FAST_ALLOCATED;
public:
DecodeTask(const URL& url, const ScheduleContext& scheduleContext, DecodeCompletionHandler&& completionHandler)
: url(url.isolatedCopy())
, scheduleContext(scheduleContext)
, completionHandler(WTFMove(completionHandler))
{
}
bool process()
{
// Syntax:
// url := data:<header>,<encodedData>
// header := [<mediatype>][;base64]
// mediatype := [<mimetype>][;charset=<charsettype>]
constexpr auto dataString = "data:"_s;
ASSERT(url.string().startsWith(dataString));
size_t headerStart = dataString.length();
size_t headerEnd = url.string().find(',', headerStart);
if (headerEnd == notFound)
return false;
if (size_t fragmentInHeader = url.string().reverseFind('#', headerEnd); fragmentInHeader != notFound)
return false;
size_t encodedDataStart = headerEnd == notFound ? headerEnd : headerEnd + 1;
auto header = StringView(url.string()).substring(headerStart, headerEnd - headerStart);
// There might one or two semicolons in the header, find the last one.
size_t mediaTypeEnd = header.reverseFind(';');
mediaTypeEnd = mediaTypeEnd == notFound ? header.length() : mediaTypeEnd;
// formatTypeStart might be at the begining of "base64" or "charset=...".
size_t formatTypeStart = mediaTypeEnd + 1;
auto formatType = header.substring(formatTypeStart, header.length() - formatTypeStart);
formatType = formatType.trim(isASCIIWhitespaceWithoutFF<UChar>);
isBase64 = equalLettersIgnoringASCIICase(formatType, "base64"_s);
// If header does not end with "base64", mediaType should be the whole header.
auto mediaType = (isBase64 ? header.left(mediaTypeEnd) : header).toString();
mediaType = mediaType.trim(isASCIIWhitespaceWithoutFF<UChar>);
if (mediaType.startsWith(';'))
mediaType = makeString("text/plain"_s, mediaType);
if (shouldRemoveFragmentIdentifier(mediaType))
url.removeFragmentIdentifier();
encodedData = StringView(url.string()).substring(encodedDataStart);
result = parseMediaType(mediaType);
return true;
}
URL url;
StringView encodedData;
bool isBase64 { false };
const ScheduleContext scheduleContext;
DecodeCompletionHandler completionHandler;
Result result;
};
static std::unique_ptr<DecodeTask> createDecodeTask(const URL& url, const ScheduleContext& scheduleContext, DecodeCompletionHandler&& completionHandler)
{
return makeUnique<DecodeTask>(
url,
scheduleContext,
WTFMove(completionHandler)
);
}
static Vector<uint8_t> decodeEscaped(const DecodeTask& task)
{
PAL::TextEncoding encodingFromCharset(task.result.charset);
auto& encoding = encodingFromCharset.isValid() ? encodingFromCharset : PAL::UTF8Encoding();
return PAL::decodeURLEscapeSequencesAsData(task.encodedData, encoding);
}
static std::optional<Result> decodeSynchronously(DecodeTask& task)
{
if (!task.process())
return std::nullopt;
if (task.isBase64) {
auto decodedData = base64Decode(PAL::decodeURLEscapeSequences(task.encodedData), Base64DecodeMode::DefaultValidatePaddingAndIgnoreWhitespace);
if (!decodedData)
return std::nullopt;
task.result.data = WTFMove(*decodedData);
} else
task.result.data = decodeEscaped(task);
task.result.data.shrinkToFit();
return WTFMove(task.result);
}
void decode(const URL& url, const ScheduleContext& scheduleContext, DecodeCompletionHandler&& completionHandler)
{
ASSERT(url.protocolIsData());
decodeQueue().dispatch([decodeTask = createDecodeTask(url, scheduleContext, WTFMove(completionHandler))]() mutable {
auto result = decodeSynchronously(*decodeTask);
#if USE(COCOA_EVENT_LOOP)
auto scheduledPairs = decodeTask->scheduleContext.scheduledPairs;
#endif
auto callCompletionHandler = [result = WTFMove(result), completionHandler = WTFMove(decodeTask->completionHandler)]() mutable {
completionHandler(WTFMove(result));
};
#if USE(COCOA_EVENT_LOOP)
RunLoop::dispatch(scheduledPairs, WTFMove(callCompletionHandler));
#else
RunLoop::main().dispatch(WTFMove(callCompletionHandler));
#endif
});
}
std::optional<Result> decode(const URL& url)
{
ASSERT(url.protocolIsData());
auto task = createDecodeTask(url, { }, nullptr);
return decodeSynchronously(*task);
}
} // namespace DataURLDecoder
} // namespace WebCore
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