#pragma once #include <string> #include <array> namespace jwt { namespace alphabet { struct base64 { static const std::array<char, 64>& data() { static std::array<char, 64> data = { {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'}}; return data; }; static const std::string& fill() { static std::string fill = "="; return fill; } }; struct base64url { static const std::array<char, 64>& data() { static std::array<char, 64> data = { {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_'}}; return data; }; static const std::string& fill() { static std::string fill = "%3d"; return fill; } }; } class base { public: template<typename T> static std::string encode(const std::string& bin) { return encode(bin, T::data(), T::fill()); } template<typename T> static std::string decode(const std::string& base) { return decode(base, T::data(), T::fill()); } private: static std::string encode(const std::string& bin, const std::array<char, 64>& alphabet, const std::string& fill) { size_t size = bin.size(); std::string res; // clear incomplete bytes size_t fast_size = size - size % 3; for (size_t i = 0; i < fast_size;) { uint32_t octet_a = (unsigned char)bin[i++]; uint32_t octet_b = (unsigned char)bin[i++]; uint32_t octet_c = (unsigned char)bin[i++]; uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c; res += alphabet[(triple >> 3 * 6) & 0x3F]; res += alphabet[(triple >> 2 * 6) & 0x3F]; res += alphabet[(triple >> 1 * 6) & 0x3F]; res += alphabet[(triple >> 0 * 6) & 0x3F]; } if (fast_size == size) return res; size_t mod = size % 3; uint32_t octet_a = fast_size < size ? (unsigned char)bin[fast_size++] : 0; uint32_t octet_b = fast_size < size ? (unsigned char)bin[fast_size++] : 0; uint32_t octet_c = fast_size < size ? (unsigned char)bin[fast_size++] : 0; uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c; switch (mod) { case 1: res += alphabet[(triple >> 3 * 6) & 0x3F]; res += alphabet[(triple >> 2 * 6) & 0x3F]; res += fill; res += fill; break; case 2: res += alphabet[(triple >> 3 * 6) & 0x3F]; res += alphabet[(triple >> 2 * 6) & 0x3F]; res += alphabet[(triple >> 1 * 6) & 0x3F]; res += fill; break; default: break; } return res; } static std::string decode(const std::string& base, const std::array<char, 64>& alphabet, const std::string& fill) { size_t size = base.size(); size_t fill_cnt = 0; while (size > fill.size()) { if (base.substr(size - fill.size(), fill.size()) == fill) { fill_cnt++; size -= fill.size(); if(fill_cnt > 2) throw std::runtime_error("Invalid input"); } else break; } if ((size + fill_cnt) % 4 != 0) throw std::runtime_error("Invalid input"); size_t out_size = size / 4 * 3; std::string res; res.reserve(out_size); auto get_sextet = [&](size_t offset) { for (size_t i = 0; i < alphabet.size(); i++) { if (alphabet[i] == base[offset]) return i; } throw std::runtime_error("Invalid input"); }; size_t fast_size = size - size % 4; for (size_t i = 0; i < fast_size;) { uint32_t sextet_a = get_sextet(i++); uint32_t sextet_b = get_sextet(i++); uint32_t sextet_c = get_sextet(i++); uint32_t sextet_d = get_sextet(i++); uint32_t triple = (sextet_a << 3 * 6) + (sextet_b << 2 * 6) + (sextet_c << 1 * 6) + (sextet_d << 0 * 6); res += (triple >> 2 * 8) & 0xFF; res += (triple >> 1 * 8) & 0xFF; res += (triple >> 0 * 8) & 0xFF; } if (fill_cnt == 0) return res; uint32_t triple = (get_sextet(fast_size) << 3 * 6) + (get_sextet(fast_size + 1) << 2 * 6); switch (fill_cnt) { case 1: triple |= (get_sextet(fast_size + 2) << 1 * 6); res += (triple >> 2 * 8) & 0xFF; res += (triple >> 1 * 8) & 0xFF; break; case 2: res += (triple >> 2 * 8) & 0xFF; break; default: break; } return res; } }; }