1/*
2 * Copyright (C) 2011 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 "QuotedPrintable.h"
33
34#include <wtf/ASCIICType.h>
35
36namespace WebCore {
37
38static const size_t maximumLineLength = 76;
39
40static const char crlfLineEnding[] = "\r\n";
41
42static size_t lengthOfLineEndingAtIndex(const char* input, size_t inputLength, size_t index)
43{
44 ASSERT(index < inputLength);
45 if (input[index] == '\n')
46 return 1; // Single LF.
47
48 if (input[index] == '\r') {
49 if ((index + 1) == inputLength || input[index + 1] != '\n')
50 return 1; // Single CR (Classic Mac OS).
51 return 2; // CR-LF.
52 }
53
54 return 0;
55}
56
57void quotedPrintableEncode(const Vector<char>& in, Vector<char>& out)
58{
59 quotedPrintableEncode(in.data(), in.size(), out);
60}
61
62void quotedPrintableEncode(const char* input, size_t inputLength, Vector<char>& out)
63{
64 out.clear();
65 out.reserveCapacity(inputLength);
66 size_t currentLineLength = 0;
67 for (size_t i = 0; i < inputLength; ++i) {
68 bool isLastCharacter = (i == inputLength - 1);
69 char currentCharacter = input[i];
70 bool requiresEncoding = false;
71 // All non-printable ASCII characters and = require encoding.
72 if ((currentCharacter < ' ' || currentCharacter > '~' || currentCharacter == '=') && currentCharacter != '\t')
73 requiresEncoding = true;
74
75 // Space and tab characters have to be encoded if they appear at the end of a line.
76 if (!requiresEncoding && (currentCharacter == '\t' || currentCharacter == ' ') && (isLastCharacter || lengthOfLineEndingAtIndex(input, inputLength, i + 1)))
77 requiresEncoding = true;
78
79 // End of line should be converted to CR-LF sequences.
80 if (!isLastCharacter) {
81 size_t lengthOfLineEnding = lengthOfLineEndingAtIndex(input, inputLength, i);
82 if (lengthOfLineEnding) {
83 out.append(crlfLineEnding, strlen(crlfLineEnding));
84 currentLineLength = 0;
85 i += (lengthOfLineEnding - 1); // -1 because we'll ++ in the for() above.
86 continue;
87 }
88 }
89
90 size_t lengthOfEncodedCharacter = 1;
91 if (requiresEncoding)
92 lengthOfEncodedCharacter += 2;
93 if (!isLastCharacter)
94 lengthOfEncodedCharacter += 1; // + 1 for the = (soft line break).
95
96 // Insert a soft line break if necessary.
97 if (currentLineLength + lengthOfEncodedCharacter > maximumLineLength) {
98 out.append('=');
99 out.append(crlfLineEnding, strlen(crlfLineEnding));
100 currentLineLength = 0;
101 }
102
103 // Finally, insert the actual character(s).
104 if (requiresEncoding) {
105 out.append('=');
106 out.append(upperNibbleToASCIIHexDigit(currentCharacter));
107 out.append(lowerNibbleToASCIIHexDigit(currentCharacter));
108 currentLineLength += 3;
109 } else {
110 out.append(currentCharacter);
111 currentLineLength++;
112 }
113 }
114}
115
116void quotedPrintableDecode(const Vector<char>& in, Vector<char>& out)
117{
118 quotedPrintableDecode(in.data(), in.size(), out);
119}
120
121void quotedPrintableDecode(const char* data, size_t dataLength, Vector<char>& out)
122{
123 out.clear();
124 if (!dataLength)
125 return;
126
127 for (size_t i = 0; i < dataLength; ++i) {
128 char currentCharacter = data[i];
129 if (currentCharacter != '=') {
130 out.append(currentCharacter);
131 continue;
132 }
133 // We are dealing with a '=xx' sequence.
134 if (dataLength - i < 3) {
135 // Unfinished = sequence, append as is.
136 out.append(currentCharacter);
137 continue;
138 }
139 char upperCharacter = data[++i];
140 char lowerCharacter = data[++i];
141 if (upperCharacter == '\r' && lowerCharacter == '\n')
142 continue;
143
144 if (!isASCIIHexDigit(upperCharacter) || !isASCIIHexDigit(lowerCharacter)) {
145 // Invalid sequence, = followed by non hex digits, just insert the characters as is.
146 out.append('=');
147 out.append(upperCharacter);
148 out.append(lowerCharacter);
149 continue;
150 }
151 out.append(static_cast<char>(toASCIIHexValue(upperCharacter, lowerCharacter)));
152 }
153}
154
155}