/******************************************************************************* * * * libretroshare base64 encoding utilities * * * * Copyright (C) 2015 Retroshare Team * * Copyright (C) 2020 Gioacchino Mazzurco * * Copyright (C) 2020 Asociación Civil Altermundi * * * * This program is free software: you can redistribute it and/or modify * * it under the terms of the GNU Lesser General Public License as * * published by the Free Software Foundation, either version 3 of the * * License, or (at your option) any later version. * * * * This program is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * * GNU Lesser General Public License for more details. * * * * You should have received a copy of the GNU Lesser General Public License * * along with this program. If not, see . * * * *******************************************************************************/ #pragma once #include #include #include #include #include #include "util/rsmemory.h" /** * Implement methods to encode e decode to base64 format as per RFC 4648 * This implementation support also the file name and URL safe base64url format * @see https://tools.ietf.org/html/rfc4648#section-5 */ class RsBase64 { public: /// Enable base64url by default static constexpr bool DEFAULT_URL_SAFE = true; /// Disable padding by default static constexpr bool DEFAULT_PADDING = false; /** * @brief Encode arbitrary data to base64 * @param[in] data pointer to the input data buffer * @param[in] len lenght of the input buffer * @param[out] outString storage for the resulting base64 encoded string * @param[in] padding set to true to enable padding to 32 bits * @param[in] urlSafe pass true for base64url format, false for base64 format */ static void encode( rs_view_ptr data, size_t len, std::string& outString, bool padding = DEFAULT_PADDING, bool urlSafe = DEFAULT_URL_SAFE ); /** * @brief Decode data from a base64 encoded string * @param[in] encoded encoded string * @param[out] decoded storage for decoded data * @return success or error details */ static std::error_condition decode( const std::string& encoded, std::vector& decoded ); /** * Remove invalid characters from base64 encoded string. * Often when copy and pasting from one progam to another long base64 * strings, new lines, spaces or other characters end up polluting the * original text. This function is useful to cleanup the pollution before * attempting to decode the message. * @param in input string * @param out storage for cleaned string. In-place operation in supported so * the same input string may be passed. * @return count of stripped invalid characters */ static size_t stripInvalid(const std::string& in, std::string& out); /** * Calculate how much bytes are needed to store the base64 encoded version * of some data. * @param decodedSize size of the original decoded data * @param padding true to enable base64 padding * @return how much bytes would take to store the encoded version */ static size_t encodedSize( size_t decodedSize, bool padding = DEFAULT_PADDING ); /** * @brief Calculate how much space is needed to store the decoded version of * a base64 encoded string * @param input encoded string * @return decoded size, plus error information on failure */ static std::tuple decodedSize( const std::string& input ); private: /// base64 conversion table static constexpr char bDict[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; /// base64url conversion table static constexpr char uDict[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; /// This reverse table supports both base64 and base64url static constexpr int8_t rDict[256] = { /* index +0 +1 +2 +3 +4 +5 +6 +7 +8 +9 +10 +11 +12 +13 +14 +15 */ /* 0 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 16 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 32 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, /* 48 */ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, 0, -1, -1, /* 64 */ -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 80 */ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63, /* 96 */ -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 112 */ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, /* 128 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 144 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 160 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 176 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 192 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 208 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 224 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 240 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, }; /// base64 padding character static constexpr char sPad = '='; /** Check if given character is valid either for base64 or for base64url * @param c character to check * @return true if valid false otherwise */ static inline bool isBase64Char(char c) { return rDict[static_cast(c)] >= 0; } /** Perform ceil division without floating point operations */ static inline size_t ceilDivision(size_t dividend, size_t divisor) { return (dividend + divisor - 1) / divisor; } };