base64编码c++版本

C&＃43;&＃43;版本的base64编码，使用vector和sring做为输入输出，原文出自http://www.adp-gmbh.ch/cpp/common/base64.html，稍微做了一些改动：

#ifndef BASE64_H
#define BASE64_H
#include
#include
std::string base64_encode(unsigned char const* , unsigned int len);
std::vector base64_decode(std::string const& s);
#endif

/*
base64.cpp and base64.h
Copyright (C) 2004-2008 Ren茅 Nyffenegger
This source code is provided ‘as-is‘, without any express or implied
warranty. In no event will the author be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this source code must not be misrepresented; you must not
claim that you wrote the original source code. If you use this source code
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original source code.
3. This notice may not be removed or altered from any source distribution.
Ren茅 Nyffenegger rene.nyffenegger@adp-gmbh.ch
dotphoenix（dotphoenix@qq.com) modified at 20140220:
change the decode out put to std::vector
*/
#include "base64.h"
#include
static const std::string base64_chars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static inline bool is_base64(unsigned char c) {
return (isalnum(c) || (c == ‘+‘) || (c == ‘/‘));
}
std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {
std::string ret;
int i = 0;
int j = 0;
unsigned char char_array_3[3];
unsigned char char_array_4[4];
while (in_len--) {
char_array_3[i++] = *(bytes_to_encode++);
if (i == 3) {
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) <<4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) <<2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;
for(i = 0; (i <4) ; i++)
ret += base64_chars[char_array_4[i]];
i = 0;
}
}
if (i)
{
for(j = i; j <3; j++)
char_array_3[j] = ‘\0‘;
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) <<4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) <<2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;
for (j = 0; (j ret += base64_chars[char_array_4[j]];
while((i++ <3))
ret += ‘=‘;
}
return ret;
}
std::vector base64_decode(std::string const& encoded_string) {
int in_len = encoded_string.size();
int i = 0;
int j = 0;
int in_ = 0;
unsigned char char_array_4[4], char_array_3[3];
std::vector ret;
while (in_len-- && ( encoded_string[in_] != ‘=‘) && is_base64(encoded_string[in_])) {
char_array_4[i++] = encoded_string[in_]; in_++;
if (i ==4) {
for (i = 0; i <4; i++)
char_array_4[i] = base64_chars.find(char_array_4[i]);
char_array_3[0] = (char_array_4[0] <<2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) <<4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) <<6) + char_array_4[3];
for (i = 0; (i <3); i++)
ret.push_back(char_array_3[i]) ;
i = 0;
}
}
if (i) {
for (j = i; j <4; j++)
char_array_4[j] = 0;
for (j = 0; j <4; j++)
char_array_4[j] = base64_chars.find(char_array_4[j]);
char_array_3[0] = (char_array_4[0] <<2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) <<4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) <<6) + char_array_4[3];
for (j = 0; (j {
ret.push_back(char_array_3[j]);
}
}
return ret;
}

#include
void base64_tester()
{
#define BINAY_LENGTH 17
unsigned char binary_data[BINAY_LENGTH] = {0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x11, 0x3A, 0x4B, 0x5C, 0x6D, 0x7E, 0x8F, 0xA0, 0xFE, 0xFF};
std::string base64 = base64_encode(binary_data, BINAY_LENGTH);
std::vector binary = base64_decode(base64);
assert(binary.size() == BINAY_LENGTH);
assert(binary[0] == binary_data[0]);
assert(binary[BINAY_LENGTH - 1] == binary_data[BINAY_LENGTH - 1]);
}