void wstrToUtf8(string& dest, const wstring& src){
dest.clear();
for (size_t i = 0; i < src.size(); i++){
wchar_t w = src[i];
if (w <= 0x7f)
dest.push_back((char)w);
else if (w <= 0x7ff){
dest.push_back(0xc0 | ((w >> 6)& 0x1f));
dest.push_back(0x80| (w & 0x3f));
}
else if (w <= 0xffff){
dest.push_back(0xe0 | ((w >> 12)& 0x0f));
dest.push_back(0x80| ((w >> 6) & 0x3f));
dest.push_back(0x80| (w & 0x3f));
}
else if (w <= 0x10ffff){
dest.push_back(0xf0 | ((w >> 18)& 0x07));
dest.push_back(0x80| ((w >> 12) & 0x3f));
dest.push_back(0x80| ((w >> 6) & 0x3f));
dest.push_back(0x80| (w & 0x3f));
}
else
dest.push_back('?');
}
}
string wstrToUtf8(const wstring& str){
string result;
wstrToUtf8(result, str);
return result;
}
//===========================================================
// base64
//===========================================================
std::wstring base64Encode(const wstring input){
string utf8_input = wstrToUtf8(input);
unsigned char const* buffer = (unsigned const char*)(utf8_input.c_str());
size_t size = utf8_input.length();
using std::wstring;
static wchar_t const* base64Table =
L"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
// for =
// size_t base64Size = (size + 2 - ((size + 2) % 3)) / 3 * 4;
// wstring result(base64Size, L'=');
size_t base64Size = ceil(size * 4.0 / 3);
wstring result(base64Size, L'');
unsigned char const* s = buffer; // source pointer
size_t di = 0; // destination index
for(size_t i = 0; i < size / 3; i++){
// input: 0000_0000 0000_0000 0000_0000
//
// out1: 0000_00
// out2: 00 0000
// out3: _0000 00
// out4: 00_0000
result[di++] = base64Table[s[0] >> 2];
result[di++] = base64Table[((s[0] << 4) | (s[1] >> 4)) & 0x3f];
result[di++] = base64Table[((s[1] << 2) | (s[2] >> 6)) & 0x3f];
result[di++] = base64Table[s[2] & 0x3f];
s += 3;
}
size_t remainSize = size % 3;
switch(remainSize){
case 0:
break;
case 1:
result[di++] = base64Table[s[0] >> 2];
result[di++] = base64Table[(s[0] << 4) & 0x3f];
break;
case 2:
result[di++] = base64Table[s[0] >> 2];
result[di++] = base64Table[((s[0] << 4) | (s[1] >> 4)) & 0x3f];
result[di++] = base64Table[(s[1] << 2) & 0x3f];
break;
default:
throw std::logic_error("Should not happen.");
}
return result;
}
int main() {
wcout.imbue(locale("korean"));
wstring plain(L"대한민국");
wcout << base64Encode(plain).c_str() << endl;
return 0;
}
dest.clear();
for (size_t i = 0; i < src.size(); i++){
wchar_t w = src[i];
if (w <= 0x7f)
dest.push_back((char)w);
else if (w <= 0x7ff){
dest.push_back(0xc0 | ((w >> 6)& 0x1f));
dest.push_back(0x80| (w & 0x3f));
}
else if (w <= 0xffff){
dest.push_back(0xe0 | ((w >> 12)& 0x0f));
dest.push_back(0x80| ((w >> 6) & 0x3f));
dest.push_back(0x80| (w & 0x3f));
}
else if (w <= 0x10ffff){
dest.push_back(0xf0 | ((w >> 18)& 0x07));
dest.push_back(0x80| ((w >> 12) & 0x3f));
dest.push_back(0x80| ((w >> 6) & 0x3f));
dest.push_back(0x80| (w & 0x3f));
}
else
dest.push_back('?');
}
}
string wstrToUtf8(const wstring& str){
string result;
wstrToUtf8(result, str);
return result;
}
//===========================================================
// base64
//===========================================================
std::wstring base64Encode(const wstring input){
string utf8_input = wstrToUtf8(input);
unsigned char const* buffer = (unsigned const char*)(utf8_input.c_str());
size_t size = utf8_input.length();
using std::wstring;
static wchar_t const* base64Table =
L"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
// for =
// size_t base64Size = (size + 2 - ((size + 2) % 3)) / 3 * 4;
// wstring result(base64Size, L'=');
size_t base64Size = ceil(size * 4.0 / 3);
wstring result(base64Size, L'');
unsigned char const* s = buffer; // source pointer
size_t di = 0; // destination index
for(size_t i = 0; i < size / 3; i++){
// input: 0000_0000 0000_0000 0000_0000
//
// out1: 0000_00
// out2: 00 0000
// out3: _0000 00
// out4: 00_0000
result[di++] = base64Table[s[0] >> 2];
result[di++] = base64Table[((s[0] << 4) | (s[1] >> 4)) & 0x3f];
result[di++] = base64Table[((s[1] << 2) | (s[2] >> 6)) & 0x3f];
result[di++] = base64Table[s[2] & 0x3f];
s += 3;
}
size_t remainSize = size % 3;
switch(remainSize){
case 0:
break;
case 1:
result[di++] = base64Table[s[0] >> 2];
result[di++] = base64Table[(s[0] << 4) & 0x3f];
break;
case 2:
result[di++] = base64Table[s[0] >> 2];
result[di++] = base64Table[((s[0] << 4) | (s[1] >> 4)) & 0x3f];
result[di++] = base64Table[(s[1] << 2) & 0x3f];
break;
default:
throw std::logic_error("Should not happen.");
}
return result;
}
int main() {
wcout.imbue(locale("korean"));
wstring plain(L"대한민국");
wcout << base64Encode(plain).c_str() << endl;
return 0;
}
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