| 141 | } |
| 142 | |
| 143 | vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid) |
| 144 | { |
| 145 | static const int decode64_table[256] = |
| 146 | { |
| 147 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 148 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 149 | -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, |
| 150 | -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, |
| 151 | 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, |
| 152 | 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, |
| 153 | 49, 50, 51, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 154 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 155 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 156 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 157 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 158 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 159 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 |
| 160 | }; |
| 161 | |
| 162 | if (pfInvalid) |
| 163 | *pfInvalid = false; |
| 164 | |
| 165 | vector<unsigned char> vchRet; |
| 166 | vchRet.reserve(strlen(p)*3/4); |
| 167 | |
| 168 | int mode = 0; |
| 169 | int left = 0; |
| 170 | |
| 171 | while (1) |
| 172 | { |
| 173 | int dec = decode64_table[(unsigned char)*p]; |
| 174 | if (dec == -1) break; |
| 175 | p++; |
| 176 | switch (mode) |
| 177 | { |
| 178 | case 0: // we have no bits and get 6 |
| 179 | left = dec; |
| 180 | mode = 1; |
| 181 | break; |
| 182 | |
| 183 | case 1: // we have 6 bits and keep 4 |
| 184 | vchRet.push_back((left<<2) | (dec>>4)); |
| 185 | left = dec & 15; |
| 186 | mode = 2; |
| 187 | break; |
| 188 | |
| 189 | case 2: // we have 4 bits and get 6, we keep 2 |
| 190 | vchRet.push_back((left<<4) | (dec>>2)); |
| 191 | left = dec & 3; |
| 192 | mode = 3; |
| 193 | break; |
| 194 | |
| 195 | case 3: // we have 2 bits and get 6 |
| 196 | vchRet.push_back((left<<6) | dec); |
| 197 | mode = 0; |
| 198 | break; |
| 199 | } |
| 200 | } |