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
30 namespace WTF {
31
32 static const char base64EncMap[64] = {
33 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
34 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
35 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
36 0x59, 0x5A, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
37 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E,
38 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76,
39 0x77, 0x78, 0x79, 0x7A, 0x30, 0x31, 0x32, 0x33,
40 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2B, 0x2F
41 };
42
43 static const char base64DecMap[128] = {
44 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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, 0x3E, 0x00, 0x00, 0x00, 0x3F,
50 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
51 0x3C, 0x3D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
52 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
53 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
54 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
55 0x17, 0x18, 0x19, 0x00, 0x00, 0x00, 0x00, 0x00,
56 0x00, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
57 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
58 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
59 0x31, 0x32, 0x33, 0x00, 0x00, 0x00, 0x00, 0x00
60 };
61
base64Encode(const char * data,unsigned length,Base64EncodePolicy policy)62 String base64Encode(const char* data, unsigned length, Base64EncodePolicy policy)
63 {
64 Vector<char> result;
65 base64Encode(data, length, result, policy);
66 return String(result.data(), result.size());
67 }
68
base64Encode(const char * data,unsigned len,Vector<char> & out,Base64EncodePolicy policy)69 void base64Encode(const char* data, unsigned len, Vector<char>& out, Base64EncodePolicy policy)
70 {
71 out.clear();
72 if (!len)
73 return;
74
75 // If the input string is pathologically large, just return nothing.
76 // Note: Keep this in sync with the "outLength" computation below.
77 // Rather than being perfectly precise, this is a bit conservative.
78 const unsigned maxInputBufferSize = UINT_MAX / 77 * 76 / 4 * 3 - 2;
79 if (len > maxInputBufferSize)
80 return;
81
82 unsigned sidx = 0;
83 unsigned didx = 0;
84
85 unsigned outLength = ((len + 2) / 3) * 4;
86
87 // Deal with the 76 character per line limit specified in RFC 2045.
88 bool insertLFs = (policy == Base64InsertLFs && outLength > 76);
89 if (insertLFs)
90 outLength += ((outLength - 1) / 76);
91
92 int count = 0;
93 out.grow(outLength);
94
95 // 3-byte to 4-byte conversion + 0-63 to ascii printable conversion
96 if (len > 1) {
97 while (sidx < len - 2) {
98 if (insertLFs) {
99 if (count && !(count % 76))
100 out[didx++] = '\n';
101 count += 4;
102 }
103 out[didx++] = base64EncMap[(data[sidx] >> 2) & 077];
104 out[didx++] = base64EncMap[((data[sidx + 1] >> 4) & 017) | ((data[sidx] << 4) & 077)];
105 out[didx++] = base64EncMap[((data[sidx + 2] >> 6) & 003) | ((data[sidx + 1] << 2) & 077)];
106 out[didx++] = base64EncMap[data[sidx + 2] & 077];
107 sidx += 3;
108 }
109 }
110
111 if (sidx < len) {
112 if (insertLFs && (count > 0) && !(count % 76))
113 out[didx++] = '\n';
114
115 out[didx++] = base64EncMap[(data[sidx] >> 2) & 077];
116 if (sidx < len - 1) {
117 out[didx++] = base64EncMap[((data[sidx + 1] >> 4) & 017) | ((data[sidx] << 4) & 077)];
118 out[didx++] = base64EncMap[(data[sidx + 1] << 2) & 077];
119 } else
120 out[didx++] = base64EncMap[(data[sidx] << 4) & 077];
121 }
122
123 // Add padding
124 while (didx < out.size()) {
125 out[didx] = '=';
126 ++didx;
127 }
128 }
129
base64Decode(const Vector<char> & in,Vector<char> & out,CharacterMatchFunctionPtr shouldIgnoreCharacter,Base64DecodePolicy policy)130 bool base64Decode(const Vector<char>& in, Vector<char>& out, CharacterMatchFunctionPtr shouldIgnoreCharacter, Base64DecodePolicy policy)
131 {
132 out.clear();
133
134 // If the input string is pathologically large, just return nothing.
135 if (in.size() > UINT_MAX)
136 return false;
137
138 return base64Decode(in.data(), in.size(), out, shouldIgnoreCharacter, policy);
139 }
140
141 template<typename T>
base64DecodeInternal(const T * data,unsigned length,Vector<char> & out,CharacterMatchFunctionPtr shouldIgnoreCharacter,Base64DecodePolicy policy)142 static inline bool base64DecodeInternal(const T* data, unsigned length, Vector<char>& out, CharacterMatchFunctionPtr shouldIgnoreCharacter, Base64DecodePolicy policy)
143 {
144 out.clear();
145 if (!length)
146 return true;
147
148 out.grow(length);
149
150 unsigned equalsSignCount = 0;
151 unsigned outLength = 0;
152 bool hadError = false;
153 for (unsigned idx = 0; idx < length; ++idx) {
154 unsigned ch = data[idx];
155 if (ch == '=') {
156 ++equalsSignCount;
157 // There should never be more than 2 padding characters.
158 if (policy == Base64ValidatePadding && equalsSignCount > 2) {
159 hadError = true;
160 break;
161 }
162 } else if (('0' <= ch && ch <= '9') || ('A' <= ch && ch <= 'Z') || ('a' <= ch && ch <= 'z') || ch == '+' || ch == '/') {
163 if (equalsSignCount) {
164 hadError = true;
165 break;
166 }
167 out[outLength++] = base64DecMap[ch];
168 } else if (!shouldIgnoreCharacter || !shouldIgnoreCharacter(ch)) {
169 hadError = true;
170 break;
171 }
172 }
173
174 if (outLength < out.size())
175 out.shrink(outLength);
176
177 if (hadError)
178 return false;
179
180 if (!outLength)
181 return !equalsSignCount;
182
183 // There should be no padding if length is a multiple of 4.
184 // We use (outLength + equalsSignCount) instead of length because we don't want to account for ignored characters.
185 if (policy == Base64ValidatePadding && equalsSignCount && (outLength + equalsSignCount) % 4)
186 return false;
187
188 // Valid data is (n * 4 + [0,2,3]) characters long.
189 if ((outLength % 4) == 1)
190 return false;
191
192 // 4-byte to 3-byte conversion
193 outLength -= (outLength + 3) / 4;
194 if (!outLength)
195 return false;
196
197 unsigned sidx = 0;
198 unsigned didx = 0;
199 if (outLength > 1) {
200 while (didx < outLength - 2) {
201 out[didx] = (((out[sidx] << 2) & 255) | ((out[sidx + 1] >> 4) & 003));
202 out[didx + 1] = (((out[sidx + 1] << 4) & 255) | ((out[sidx + 2] >> 2) & 017));
203 out[didx + 2] = (((out[sidx + 2] << 6) & 255) | (out[sidx + 3] & 077));
204 sidx += 4;
205 didx += 3;
206 }
207 }
208
209 if (didx < outLength)
210 out[didx] = (((out[sidx] << 2) & 255) | ((out[sidx + 1] >> 4) & 003));
211
212 if (++didx < outLength)
213 out[didx] = (((out[sidx + 1] << 4) & 255) | ((out[sidx + 2] >> 2) & 017));
214
215 if (outLength < out.size())
216 out.shrink(outLength);
217
218 return true;
219 }
220
base64Decode(const char * data,unsigned length,Vector<char> & out,CharacterMatchFunctionPtr shouldIgnoreCharacter,Base64DecodePolicy policy)221 bool base64Decode(const char* data, unsigned length, Vector<char>& out, CharacterMatchFunctionPtr shouldIgnoreCharacter, Base64DecodePolicy policy)
222 {
223 return base64DecodeInternal<LChar>(reinterpret_cast<const LChar*>(data), length, out, shouldIgnoreCharacter, policy);
224 }
225
base64Decode(const UChar * data,unsigned length,Vector<char> & out,CharacterMatchFunctionPtr shouldIgnoreCharacter,Base64DecodePolicy policy)226 bool base64Decode(const UChar* data, unsigned length, Vector<char>& out, CharacterMatchFunctionPtr shouldIgnoreCharacter, Base64DecodePolicy policy)
227 {
228 return base64DecodeInternal<UChar>(data, length, out, shouldIgnoreCharacter, policy);
229 }
230
base64Decode(const String & in,Vector<char> & out,CharacterMatchFunctionPtr shouldIgnoreCharacter,Base64DecodePolicy policy)231 bool base64Decode(const String& in, Vector<char>& out, CharacterMatchFunctionPtr shouldIgnoreCharacter, Base64DecodePolicy policy)
232 {
233 if (in.isEmpty())
234 return base64DecodeInternal<LChar>(0, 0, out, shouldIgnoreCharacter, policy);
235 if (in.is8Bit())
236 return base64DecodeInternal<LChar>(in.characters8(), in.length(), out, shouldIgnoreCharacter, policy);
237 return base64DecodeInternal<UChar>(in.characters16(), in.length(), out, shouldIgnoreCharacter, policy);
238 }
239
240 } // namespace WTF
241