1 /* 2 Copyright (C) 2000-2001 Dawit Alemayehu <adawit (at) kde.org> 3 Copyright (C) 2006 Alexey Proskuryakov <ap (at) webkit.org> 4 Copyright (C) 2007, 2008 Apple Inc. All rights reserved. 5 Copyright (C) 2010 Patrick Gansterer <paroga (at) 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 Tschalr 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 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 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 } 129 130 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> 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 } 220 221 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 } 225 226 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 } 230 231 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
