146 lines
6.2 KiB
C++
146 lines
6.2 KiB
C++
#include <algorithm>
|
|
#include <limits>
|
|
#include <stdexcept>
|
|
|
|
#include <basen/base64.hpp>
|
|
#include <basen/baseN.hpp>
|
|
#include <basen/Exception.hpp>
|
|
|
|
namespace base64
|
|
{
|
|
const char digits[] =
|
|
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
|
|
const uint8_t map[] = {
|
|
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,
|
|
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, 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, 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,
|
|
//
|
|
};
|
|
bool isValid(const char *str, size_t str_size) noexcept
|
|
{
|
|
return base64::isValid(std::string_view(str, str_size));
|
|
}
|
|
bool isValid(std::string_view str) noexcept
|
|
{
|
|
std::string_view sv(str.begin(), std::find_if(str.rbegin(), str.rend(), [](char ch)
|
|
{ return ch != '='; })
|
|
.base());
|
|
if (2 + sv.size() < str.size())
|
|
{
|
|
return false;
|
|
}
|
|
return baseN::isValid(sv, map);
|
|
}
|
|
size_t sizeEncoded(std::span<const uint8_t> data)
|
|
{
|
|
size_t str_size = data.size() / 3;
|
|
if (str_size > std::numeric_limits<size_t>::max() / 4)
|
|
{
|
|
throw basen::Exception(basen::Exception::Code::OVERFLOW);
|
|
}
|
|
str_size = str_size * 4 + (data.size() % 3 ? 4 : 0);
|
|
return str_size;
|
|
}
|
|
size_t sizeDecoded(std::string_view str) noexcept
|
|
{
|
|
auto size = std::distance(str.begin(), std::find_if(str.rbegin(), str.rend(), [](char ch)
|
|
{ return ch != '='; })
|
|
.base());
|
|
return size / 4 * 3 + (size % 4 ? size % 4 - 1 : 0);
|
|
}
|
|
void encode(const uint8_t *data, size_t data_size, char *str, size_t str_size)
|
|
{
|
|
if (str_size < base64::sizeEncoded(std::span<const uint8_t>(data, data_size)))
|
|
{
|
|
throw basen::Exception(basen::Exception::Code::LENGTH);
|
|
}
|
|
for (size_t i = 0; i < data_size / 3; i++)
|
|
{
|
|
str[i * 4] = digits[data[i * 3] >> 2];
|
|
str[i * 4 + 1] = digits[(data[i * 3] << 4 | data[i * 3 + 1] >> 4) & 0x3F];
|
|
str[i * 4 + 2] = digits[(data[i * 3 + 1] << 2 | data[i * 3 + 2] >> 6) & 0x3F];
|
|
str[i * 4 + 3] = digits[data[i * 3 + 2] & 0x3F];
|
|
}
|
|
size_t last_idx = data_size / 3 * 4;
|
|
switch (data_size % 3)
|
|
{
|
|
case 1:
|
|
str[last_idx] = digits[data[data_size - 1] >> 2];
|
|
str[last_idx + 1] = digits[data[data_size - 1] << 4 & 0x30];
|
|
str[last_idx + 2] = '=';
|
|
str[last_idx + 3] = '=';
|
|
break;
|
|
case 2:
|
|
str[last_idx] = digits[data[data_size - 2] >> 2];
|
|
str[last_idx + 1] = digits[(data[data_size - 2] << 4 | data[data_size - 1] >> 4) & 0x3F];
|
|
str[last_idx + 2] = digits[data[data_size - 1] << 2 & 0x3F];
|
|
str[last_idx + 3] = '=';
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
std::string encode(std::span<const uint8_t> data)
|
|
{
|
|
std::string str(base64::sizeEncoded(data), ' ');
|
|
base64::encode(data.data(), data.size(), str.data(), str.size());
|
|
return str;
|
|
}
|
|
void decode(const char *str, size_t str_size, uint8_t *data, size_t data_size)
|
|
{
|
|
std::string_view sv(str, str_size);
|
|
if (data_size < base64::sizeDecoded(sv))
|
|
{
|
|
throw basen::Exception(basen::Exception::Code::LENGTH);
|
|
}
|
|
if (!base64::isValid(sv))
|
|
{
|
|
throw basen::Exception(basen::Exception::Code::OUT_OF_ALPH);
|
|
}
|
|
auto size = std::distance(sv.begin(), std::find_if(sv.rbegin(), sv.rend(), [](char ch)
|
|
{ return ch != '='; })
|
|
.base());
|
|
if (sv.size() % 4 != 0 || sv.size() - size > 2)
|
|
{
|
|
throw basen::Exception(basen::Exception::Code::PADDING);
|
|
}
|
|
for (auto i = 0; i < size / 4; i++)
|
|
{
|
|
data[i * 3] = map[(uint8_t)str[i * 4]] << 2 | map[(uint8_t)str[i * 4 + 1]] >> 4;
|
|
data[i * 3 + 1] = map[(uint8_t)str[i * 4 + 1]] << 4 | map[(uint8_t)str[i * 4 + 2]] >> 2;
|
|
data[i * 3 + 2] = map[(uint8_t)str[i * 4 + 2]] << 6 | map[(uint8_t)str[i * 4 + 3]];
|
|
}
|
|
size_t last_idx = size / 4 * 3;
|
|
switch (size % 4)
|
|
{
|
|
case 2:
|
|
data[last_idx] = map[(uint8_t)str[size - 2]] << 2 | map[(uint8_t)str[size - 1]] >> 4;
|
|
break;
|
|
case 3:
|
|
data[last_idx] = map[(uint8_t)str[size - 3]] << 2 | map[(uint8_t)str[size - 2]] >> 4;
|
|
data[last_idx + 1] = map[(uint8_t)str[size - 2]] << 4 | map[(uint8_t)str[size - 1]] >> 2;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
std::vector<uint8_t> decode(std::string_view str)
|
|
{
|
|
std::vector<uint8_t> data(base64::sizeDecoded(str));
|
|
base64::decode(str.data(), str.size(), data.data(), data.size());
|
|
return data;
|
|
}
|
|
} |