1 /*
2 Copyright (C) 2000-2001 Dawit Alemayehu <adawit@kde.org>
3 Copyright (C) 2006 Alexey Proskuryakov <ap@webkit.org>
4 Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
5 Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU Lesser General Public License (LGPL)
9 version 2 as published by the Free Software Foundation.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU Library General Public
17 License along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19
20 This code is based on the java implementation in HTTPClient
21 package by Ronald Tschalär Copyright (C) 1996-1999.
22 */
23
24 #include "config.h"
25 #include "Base64.h"
26
27 #include <limits.h>
28 #include <wtf/StringExtras.h>
29 #include <wtf/text/WTFString.h>
30
31 namespace WebCore {
32
33 static const char base64EncMap[64] = {
34 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
35 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
36 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
37 0x59, 0x5A, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
38 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E,
39 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76,
40 0x77, 0x78, 0x79, 0x7A, 0x30, 0x31, 0x32, 0x33,
41 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2B, 0x2F
42 };
43
44 static const char base64DecMap[128] = {
45 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
46 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
47 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
48 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
49 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
50 0x00, 0x00, 0x00, 0x3E, 0x00, 0x00, 0x00, 0x3F,
51 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
52 0x3C, 0x3D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
53 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
54 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
55 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
56 0x17, 0x18, 0x19, 0x00, 0x00, 0x00, 0x00, 0x00,
57 0x00, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
58 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
59 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
60 0x31, 0x32, 0x33, 0x00, 0x00, 0x00, 0x00, 0x00
61 };
62
base64Encode(const char * data,unsigned length,bool insertLFs)63 String base64Encode(const char* data, unsigned length, bool insertLFs)
64 {
65 Vector<char> result;
66 base64Encode(data, length, result, insertLFs);
67 return String(result.data(), result.size());
68 }
69
base64Encode(const char * data,unsigned len,Vector<char> & out,bool insertLFs)70 void base64Encode(const char* data, unsigned len, Vector<char>& out, bool insertLFs)
71 {
72 out.clear();
73 if (!len)
74 return;
75
76 // If the input string is pathologically large, just return nothing.
77 // Note: Keep this in sync with the "outLength" computation below.
78 // Rather than being perfectly precise, this is a bit conservative.
79 const unsigned maxInputBufferSize = UINT_MAX / 77 * 76 / 4 * 3 - 2;
80 if (len > maxInputBufferSize)
81 return;
82
83 unsigned sidx = 0;
84 unsigned didx = 0;
85
86 unsigned outLength = ((len + 2) / 3) * 4;
87
88 // Deal with the 76 character per line limit specified in RFC 2045.
89 insertLFs = (insertLFs && outLength > 76);
90 if (insertLFs)
91 outLength += ((outLength - 1) / 76);
92
93 int count = 0;
94 out.grow(outLength);
95
96 // 3-byte to 4-byte conversion + 0-63 to ascii printable conversion
97 if (len > 1) {
98 while (sidx < len - 2) {
99 if (insertLFs) {
100 if (count && !(count % 76))
101 out[didx++] = '\n';
102 count += 4;
103 }
104 out[didx++] = base64EncMap[(data[sidx] >> 2) & 077];
105 out[didx++] = base64EncMap[((data[sidx + 1] >> 4) & 017) | ((data[sidx] << 4) & 077)];
106 out[didx++] = base64EncMap[((data[sidx + 2] >> 6) & 003) | ((data[sidx + 1] << 2) & 077)];
107 out[didx++] = base64EncMap[data[sidx + 2] & 077];
108 sidx += 3;
109 }
110 }
111
112 if (sidx < len) {
113 if (insertLFs && (count > 0) && !(count % 76))
114 out[didx++] = '\n';
115
116 out[didx++] = base64EncMap[(data[sidx] >> 2) & 077];
117 if (sidx < len - 1) {
118 out[didx++] = base64EncMap[((data[sidx + 1] >> 4) & 017) | ((data[sidx] << 4) & 077)];
119 out[didx++] = base64EncMap[(data[sidx + 1] << 2) & 077];
120 } else
121 out[didx++] = base64EncMap[(data[sidx] << 4) & 077];
122 }
123
124 // Add padding
125 while (didx < out.size()) {
126 out[didx] = '=';
127 didx++;
128 }
129 }
130
base64Decode(const Vector<char> & in,Vector<char> & out,Base64DecodePolicy policy)131 bool base64Decode(const Vector<char>& in, Vector<char>& out, Base64DecodePolicy policy)
132 {
133 out.clear();
134
135 // If the input string is pathologically large, just return nothing.
136 if (in.size() > UINT_MAX)
137 return false;
138
139 return base64Decode(in.data(), in.size(), out, policy);
140 }
141
142 template<typename T>
base64DecodeInternal(const T * data,unsigned len,Vector<char> & out,Base64DecodePolicy policy)143 static inline bool base64DecodeInternal(const T* data, unsigned len, Vector<char>& out, Base64DecodePolicy policy)
144 {
145 out.clear();
146 if (!len)
147 return true;
148
149 out.grow(len);
150
151 bool sawEqualsSign = false;
152 unsigned outLength = 0;
153 for (unsigned idx = 0; idx < len; idx++) {
154 unsigned ch = data[idx];
155 if (ch == '=')
156 sawEqualsSign = true;
157 else if (('0' <= ch && ch <= '9') || ('A' <= ch && ch <= 'Z') || ('a' <= ch && ch <= 'z') || ch == '+' || ch == '/') {
158 if (sawEqualsSign)
159 return false;
160 out[outLength] = base64DecMap[ch];
161 outLength++;
162 } else if (policy == FailOnInvalidCharacter || (policy == IgnoreWhitespace && !isSpaceOrNewline(ch)))
163 return false;
164 }
165
166 if (!outLength)
167 return !sawEqualsSign;
168
169 // Valid data is (n * 4 + [0,2,3]) characters long.
170 if ((outLength % 4) == 1)
171 return false;
172
173 // 4-byte to 3-byte conversion
174 outLength -= (outLength + 3) / 4;
175 if (!outLength)
176 return false;
177
178 unsigned sidx = 0;
179 unsigned didx = 0;
180 if (outLength > 1) {
181 while (didx < outLength - 2) {
182 out[didx] = (((out[sidx] << 2) & 255) | ((out[sidx + 1] >> 4) & 003));
183 out[didx + 1] = (((out[sidx + 1] << 4) & 255) | ((out[sidx + 2] >> 2) & 017));
184 out[didx + 2] = (((out[sidx + 2] << 6) & 255) | (out[sidx + 3] & 077));
185 sidx += 4;
186 didx += 3;
187 }
188 }
189
190 if (didx < outLength)
191 out[didx] = (((out[sidx] << 2) & 255) | ((out[sidx + 1] >> 4) & 003));
192
193 if (++didx < outLength)
194 out[didx] = (((out[sidx + 1] << 4) & 255) | ((out[sidx + 2] >> 2) & 017));
195
196 if (outLength < out.size())
197 out.shrink(outLength);
198
199 return true;
200 }
201
base64Decode(const char * data,unsigned len,Vector<char> & out,Base64DecodePolicy policy)202 bool base64Decode(const char* data, unsigned len, Vector<char>& out, Base64DecodePolicy policy)
203 {
204 return base64DecodeInternal<char>(data, len, out, policy);
205 }
206
base64Decode(const String & in,Vector<char> & out,Base64DecodePolicy policy)207 bool base64Decode(const String& in, Vector<char>& out, Base64DecodePolicy policy)
208 {
209 return base64DecodeInternal<UChar>(in.characters(), in.length(), out, policy);
210 }
211
212 } // namespace WebCore
213