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/*
* Copyright (C) 2011 Google 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:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
* OWNER OR 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 "QuotedPrintable.h"
#include <wtf/ASCIICType.h>
#include <wtf/Vector.h>
namespace WebCore {
static const size_t maximumLineLength = 76;
static const char crlfLineEnding[] = "\r\n";
static size_t lengthOfLineEndingAtIndex(const char* input, size_t inputLength, size_t index)
{
ASSERT_WITH_SECURITY_IMPLICATION(index < inputLength);
if (input[index] == '\n')
return 1; // Single LF.
if (input[index] == '\r') {
if ((index + 1) == inputLength || input[index + 1] != '\n')
return 1; // Single CR (Classic Mac OS).
return 2; // CR-LF.
}
return 0;
}
void quotedPrintableEncode(const Vector<char>& in, Vector<char>& out)
{
quotedPrintableEncode(in.data(), in.size(), out);
}
void quotedPrintableEncode(const char* input, size_t inputLength, Vector<char>& out)
{
out.clear();
out.reserveCapacity(inputLength);
size_t currentLineLength = 0;
for (size_t i = 0; i < inputLength; ++i) {
bool isLastCharacter = (i == inputLength - 1);
char currentCharacter = input[i];
bool requiresEncoding = false;
// All non-printable ASCII characters and = require encoding.
if ((currentCharacter < ' ' || currentCharacter > '~' || currentCharacter == '=') && currentCharacter != '\t')
requiresEncoding = true;
// Space and tab characters have to be encoded if they appear at the end of a line.
if (!requiresEncoding && (currentCharacter == '\t' || currentCharacter == ' ') && (isLastCharacter || lengthOfLineEndingAtIndex(input, inputLength, i + 1)))
requiresEncoding = true;
// End of line should be converted to CR-LF sequences.
if (!isLastCharacter) {
size_t lengthOfLineEnding = lengthOfLineEndingAtIndex(input, inputLength, i);
if (lengthOfLineEnding) {
out.append(crlfLineEnding, strlen(crlfLineEnding));
currentLineLength = 0;
i += (lengthOfLineEnding - 1); // -1 because we'll ++ in the for() above.
continue;
}
}
size_t lengthOfEncodedCharacter = 1;
if (requiresEncoding)
lengthOfEncodedCharacter += 2;
if (!isLastCharacter)
lengthOfEncodedCharacter += 1; // + 1 for the = (soft line break).
// Insert a soft line break if necessary.
if (currentLineLength + lengthOfEncodedCharacter > maximumLineLength) {
out.append('=');
out.append(crlfLineEnding, strlen(crlfLineEnding));
currentLineLength = 0;
}
// Finally, insert the actual character(s).
if (requiresEncoding) {
out.append('=');
out.append(upperNibbleToASCIIHexDigit(currentCharacter));
out.append(lowerNibbleToASCIIHexDigit(currentCharacter));
currentLineLength += 3;
} else {
out.append(currentCharacter);
currentLineLength++;
}
}
}
void quotedPrintableDecode(const Vector<char>& in, Vector<char>& out)
{
quotedPrintableDecode(in.data(), in.size(), out);
}
void quotedPrintableDecode(const char* data, size_t dataLength, Vector<char>& out)
{
out.clear();
if (!dataLength)
return;
for (size_t i = 0; i < dataLength; ++i) {
char currentCharacter = data[i];
if (currentCharacter != '=') {
out.append(currentCharacter);
continue;
}
// We are dealing with a '=xx' sequence.
if (dataLength - i < 3) {
// Unfinished = sequence, append as is.
out.append(currentCharacter);
continue;
}
char upperCharacter = data[++i];
char lowerCharacter = data[++i];
if (upperCharacter == '\r' && lowerCharacter == '\n')
continue;
if (!isASCIIHexDigit(upperCharacter) || !isASCIIHexDigit(lowerCharacter)) {
// Invalid sequence, = followed by non hex digits, just insert the characters as is.
out.append('=');
out.append(upperCharacter);
out.append(lowerCharacter);
continue;
}
out.append(static_cast<char>(toASCIIHexValue(upperCharacter, lowerCharacter)));
}
}
}