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편집 파일: modp_b64.h

/* -*- mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 4 -*- */ /* vi: set expandtab shiftwidth=4 tabstop=4: */ /** * \file modp_b64.h * \brief High performance base 64 encode and decode * */ /* * \file * <PRE> * High performance base64 encoder / decoder * * Copyright &copy; 2005, 2006, 2007 Nick Galbreath -- nickg [at] client9 [dot] com * All rights reserved. * * Modified for inclusion in Phusion Passenger. * * http://code.google.com/p/stringencoders/ * * Released under bsd license. See modp_b64.c for details. * </pre> * * This uses the standard base 64 alphabet. If you are planning * to embed a base 64 encoding inside a URL use modp_b64w instead. * */ #ifndef COM_MODP_STRINGENCODERS_B64 #define COM_MODP_STRINGENCODERS_B64 #include <stddef.h> #ifdef __cplusplus extern "C" { #endif /** * \brief Encode a raw binary string into base 64. * \param[out] dest should be allocated by the caller to contain * at least modp_b64_encode_len(len) bytes (see below) * This will contain the null-terminated b64 encoded result * \param[in] src contains the bytes * \param[in] len contains the number of bytes in the src * \return length of the destination string plus the ending null byte * i.e. the result will be equal to strlen(dest) + 1 * * Example * * \code * char* src = ...; * int srclen = ...; //the length of number of bytes in src * char* dest = (char*) malloc(modp_b64_encode_len); * int len = modp_b64_encode(dest, src, sourcelen); * if (len == -1) { * printf("Error\n"); * } else { * printf("b64 = %s\n", dest); * } * \endcode * */ size_t modp_b64_encode(char* dest, const char* str, size_t len); /** * Decode a base64 encoded string * * \param[out] dest should be allocated by the caller to contain at least * len * 3 / 4 bytes. The destination cannot be the same as the source * They must be different buffers. * \param[in] src should contain exactly len bytes of b64 characters. * if src contains -any- non-base characters (such as white * space, -1 is returned. * \param[in] len is the length of src * * \return the length (strlen) of the output, or -1 if unable to * decode * * \code * char* src = ...; * int srclen = ...; // or if you don't know use strlen(src) * char* dest = (char*) malloc(modp_b64_decode_len(srclen)); * int len = modp_b64_decode(dest, src, sourcelen); * if (len == -1) { error } * \endcode */ size_t modp_b64_decode(char* dest, const char* src, size_t len); /** * Given a source string of length len, this returns the amount of * memory the destination string should have. * * remember, this is integer math * 3 bytes turn into 4 chars * ceiling[len / 3] * 4 + 1 * * +1 is for any extra null. */ #define modp_b64_encode_len(A) ((A+2)/3 * 4 + 1) /** * Given a base64 string of length len, * this returns the amount of memory required for output string * It maybe be more than the actual number of bytes written. * NOTE: remember this is integer math * this allocates a bit more memory than traditional versions of b64 * decode 4 chars turn into 3 bytes * floor[len * 3/4] + 2 */ #define modp_b64_decode_len(A) (A / 4 * 3 + 2) /** * Will return the strlen of the output from encoding. * This may be less than the required number of bytes allocated. * * This allows you to 'deserialized' a struct * \code * char* b64encoded = "..."; * int len = strlen(b64encoded); * * struct datastuff foo; * if (modp_b64_encode_strlen(sizeof(struct datastuff)) != len) { * // wrong size * return false; * } else { * // safe to do; * if (modp_b64_decode((char*) &foo, b64encoded, len) == -1) { * // bad characters * return false; * } * } * // foo is filled out now * \endcode */ #define modp_b64_encode_strlen(A) ((A + 2)/ 3 * 4) #ifdef __cplusplus } // extern "C" #include <cstring> #include <string> #include <stdexcept> namespace modp { /** \brief b64 encode a cstr with len * * \param[in] s the input string to encode * \param[in] len the length of the input string * \return a newly allocated b64 string. Empty if failed. */ inline std::string b64_encode(const char* s, size_t len) { std::string x(modp_b64_encode_len(len), '\0'); size_t d = modp_b64_encode(const_cast<char*>(x.data()), s, len); if (d == (size_t)-1) { throw std::runtime_error("error encoding base64"); } else { x.erase(d, std::string::npos); } return x; } /** \brief b64 encode a cstr * * \param[in] s the input string to encode * \return a newly allocated b64 string. Empty if failed. */ inline std::string b64_encode(const char* s) { return b64_encode(s, strlen(s)); } /** \brief b64 encode a const std::string * * \param[in] s the input string to encode * \return a newly allocated b64 string. Empty if failed. */ inline std::string b64_encode(const std::string& s) { return b64_encode(s.data(), s.size()); } /** * base 64 encode a string (self-modifing) * * This function is for C++ only (duh) * * \param[in,out] s the string to be decoded * \return a reference to the input string */ inline std::string& b64_encode(std::string& s) { std::string x(b64_encode(s.data(), s.size())); s.swap(x); return s; } inline std::string b64_decode(const char* src, size_t len) { std::string x(modp_b64_decode_len(len)+1, '\0'); size_t d = modp_b64_decode(const_cast<char*>(x.data()), src, len); if (d == (size_t)-1) { throw std::runtime_error("error decoding base64"); } else { x.erase(d, std::string::npos); } return x; } inline std::string b64_decode(const char* src) { return b64_decode(src, strlen(src)); } /** * base 64 decode a string (self-modifing) * On failure, the string is empty. * * This function is for C++ only (duh) * * \param[in,out] s the string to be decoded * \return a reference to the input string */ inline std::string& b64_decode(std::string& s) { std::string x(b64_decode(s.data(), s.size())); s.swap(x); return s; } inline std::string b64_decode(const std::string& s) { return b64_decode(s.data(), s.size()); } } #endif /* __cplusplus */ #endif /* MODP_B64 */