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 #include "wtf/text/WTFString.h" 30 31 namespace WTF { 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 63 String base64Encode(const char* data, unsigned length, Base64EncodePolicy policy) 64 { 65 Vector<char> result; 66 base64Encode(data, length, result, policy); 67 return String(result.data(), result.size()); 68 } 69 70 void base64Encode(const char* data, unsigned len, Vector<char>& out, Base64EncodePolicy policy) 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 bool insertLFs = (policy == Base64InsertLFs && 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 } 130 131 bool base64Decode(const Vector<char>& in, Vector<char>& out, Base64InvalidCharactersPolicy charactersPolicy, Base64PaddingValidationPolicy paddingPolicy) 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, charactersPolicy, paddingPolicy); 140 } 141 142 template<typename T> 143 static inline bool base64DecodeInternal(const T* data, unsigned length, Vector<char>& out, Base64InvalidCharactersPolicy charactersPolicy, Base64PaddingValidationPolicy paddingPolicy) 144 { 145 out.clear(); 146 if (!length) 147 return true; 148 149 unsigned dataLength = length; 150 if (paddingPolicy == Base64StrictPaddingValidation) { 151 if (!(dataLength % 4)) { 152 // There may be 2 = padding max. 153 while (data[dataLength - 1] == '=' && dataLength >= (length - 2)) 154 --dataLength; 155 } 156 if (dataLength % 4 == 1) 157 return false; 158 } 159 160 out.grow(length); 161 162 bool sawEqualsSign = false; 163 unsigned outLength = 0; 164 for (unsigned idx = 0; idx < length; ++idx) { 165 unsigned ch = data[idx]; 166 if (ch == '=') { 167 sawEqualsSign = true; 168 if (paddingPolicy == Base64StrictPaddingValidation && idx < dataLength) 169 return false; 170 } else if (('0' <= ch && ch <= '9') || ('A' <= ch && ch <= 'Z') || ('a' <= ch && ch <= 'z') || ch == '+' || ch == '/') { 171 if (sawEqualsSign) 172 return false; 173 out[outLength] = base64DecMap[ch]; 174 ++outLength; 175 } else if (charactersPolicy == Base64FailOnInvalidCharacter || (charactersPolicy == Base64IgnoreWhitespace && !isSpaceOrNewline(ch))) 176 return false; 177 } 178 179 if (!outLength) 180 return !sawEqualsSign; 181 182 // Valid data is (n * 4 + [0,2,3]) characters long. 183 if ((outLength % 4) == 1) 184 return false; 185 186 // 4-byte to 3-byte conversion 187 outLength -= (outLength + 3) / 4; 188 if (!outLength) 189 return false; 190 191 unsigned sidx = 0; 192 unsigned didx = 0; 193 if (outLength > 1) { 194 while (didx < outLength - 2) { 195 out[didx] = (((out[sidx] << 2) & 255) | ((out[sidx + 1] >> 4) & 003)); 196 out[didx + 1] = (((out[sidx + 1] << 4) & 255) | ((out[sidx + 2] >> 2) & 017)); 197 out[didx + 2] = (((out[sidx + 2] << 6) & 255) | (out[sidx + 3] & 077)); 198 sidx += 4; 199 didx += 3; 200 } 201 } 202 203 if (didx < outLength) 204 out[didx] = (((out[sidx] << 2) & 255) | ((out[sidx + 1] >> 4) & 003)); 205 206 if (++didx < outLength) 207 out[didx] = (((out[sidx + 1] << 4) & 255) | ((out[sidx + 2] >> 2) & 017)); 208 209 if (outLength < out.size()) 210 out.shrink(outLength); 211 212 return true; 213 } 214 215 bool base64Decode(const char* data, unsigned length, Vector<char>& out, Base64InvalidCharactersPolicy charactersPolicy, Base64PaddingValidationPolicy paddingPolicy) 216 { 217 return base64DecodeInternal<LChar>(reinterpret_cast<const LChar*>(data), length, out, charactersPolicy, paddingPolicy); 218 } 219 220 bool base64Decode(const String& in, Vector<char>& out, Base64InvalidCharactersPolicy charactersPolicy, Base64PaddingValidationPolicy paddingPolicy) 221 { 222 if (in.isEmpty()) 223 return base64DecodeInternal<LChar>(0, 0, out, charactersPolicy, paddingPolicy); 224 if (in.is8Bit()) 225 return base64DecodeInternal<LChar>(in.characters8(), in.length(), out, charactersPolicy, paddingPolicy); 226 return base64DecodeInternal<UChar>(in.characters16(), in.length(), out, charactersPolicy, paddingPolicy); 227 } 228 229 } // namespace WTF 230
