/* * Copyright (c) 2013 Isode Limited. * All rights reserved. * See the COPYING file for more information. */ #include <Swiften/StringCodecs/Base64.h> #pragma clang diagnostic ignored "-Wconversion" using namespace Swift; namespace { const char* encodeMap = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; const unsigned char decodeMap[255] = { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 62, 255, 255, 255, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255, 255, 255, 255, 255, 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 255, 255, 255, 255, 255, 255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 255, 255, 255, 255, 255 }; template<typename ResultType, typename InputType> ResultType encodeDetail(const InputType& input) { ResultType result; size_t i = 0; for (; i < (input.size()/3)*3; i += 3) { unsigned int c = input[i+2] | (input[i+1]<<8) | (input[i]<<16); result.push_back(encodeMap[(c&0xFC0000)>>18]); result.push_back(encodeMap[(c&0x3F000)>>12]); result.push_back(encodeMap[(c&0xFC0)>>6]); result.push_back(encodeMap[c&0x3F]); } if (input.size() % 3 == 2) { unsigned int c = (input[i+1]<<8) | (input[i]<<16); result.push_back(encodeMap[(c&0xFC0000)>>18]); result.push_back(encodeMap[(c&0x3F000)>>12]); result.push_back(encodeMap[(c&0xFC0)>>6]); result.push_back('='); } else if (input.size() % 3 == 1) { unsigned int c = input[i]<<16; result.push_back(encodeMap[(c&0xFC0000)>>18]); result.push_back(encodeMap[(c&0x3F000)>>12]); result.push_back('='); result.push_back('='); } return result; } } std::string Base64::encode(const ByteArray& s) { return encodeDetail<std::string>(s); } SafeByteArray Base64::encode(const SafeByteArray& s) { return encodeDetail<SafeByteArray>(s); } ByteArray Base64::decode(const std::string& input) { ByteArray result; if (input.size() % 4) { return ByteArray(); } for (size_t i = 0; i < input.size(); i += 4) { unsigned char c1 = input[i+0]; unsigned char c2 = input[i+1]; unsigned char c3 = input[i+2]; unsigned char c4 = input[i+3]; if (c3 == '=') { unsigned int c = (((decodeMap[c1]<<6)|decodeMap[c2])&0xFF0)>>4; result.push_back(c); } else if (c4 == '=') { unsigned int c = (((decodeMap[c1]<<12)|(decodeMap[c2]<<6)|decodeMap[c3])&0x3FFFC)>>2; result.push_back((c&0xFF00) >> 8); result.push_back(c&0xFF); } else { unsigned int c = (decodeMap[c1]<<18) | (decodeMap[c2]<<12) | (decodeMap[c3]<<6) | decodeMap[c4]; result.push_back((c&0xFF0000) >> 16); result.push_back((c&0xFF00) >> 8); result.push_back(c&0xFF); } } return result; }