.h文件：
#pragma once
#include
using namespace std;
class zbase64
{
public:
/*编码
databyte
[in]输入的数据长度,以字节为单位
*/
string encode(const unsigned char* data, int databyte);
/*解码
databyte
[in]输入的数据长度,以字节为单位
outbyte
[out]输出的数据长度,以字节为单位,请不要通过返回值计算
输出数据的长度
*/
string decode(const char* data, int databyte, int& outbyte);
};
.cpp文件：
#include"stdafx.h"
#include "zbase64.h"
string zbase64::encode(const unsigned char* data, int databyte)
{
//编码表
const char encodetable[] = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789 /";
//返回值
string strencode;
unsigned char tmp[4] = {
0 };
int linelength = 0;
for (int i = 0; i<(int)(databyte / 3); i )
{
tmp[1] = *data ;
tmp[2] = *data ;
tmp[3] = *data ;
strencode = encodetable[tmp[1] >> 2];
strencode = encodetable[((tmp[1] << 4) | (tmp[2] >> 4)) & 0x3f];
strencode = encodetable[((tmp[2] << 2) | (tmp[3] >> 6)) & 0x3f];
strencode = encodetable[tmp[3] & 0x3f];
if (linelength = 4, linelength == 76) {
strencode = "\r\n"; linelength = 0; }
}
//对剩余数据进行编码
int mod = databyte % 3;
if (mod == 1)
{
tmp[1] = *data ;
strencode = encodetable[(tmp[1] & 0xfc) >> 2];
strencode = encodetable[((tmp[1] & 0x03) << 4)];
strencode = "==";
}
else if (mod == 2)
{
tmp[1] = *data ;
tmp[2] = *data ;
strencode = encodetable[(tmp[1] & 0xfc) >> 2];
strencode = encodetable[((tmp[1] & 0x03) << 4) | ((tmp[2] & 0xf0) >> 4)];
strencode = encodetable[((tmp[2] & 0x0f) << 2)];
strencode = "=";
}
return strencode;
}
string zbase64::decode(const char* data, int databyte, int& outbyte)
{
//解码表
const char decodetable[] =
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
62, // ' '
0, 0, 0,
63, // '/'
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'
0, 0, 0, 0, 0, 0, 0,
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, // 'a'-'z'
0, 0, 0, 0, 0, 0,
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, // 'a'-'z'
};
//返回值
string strdecode;
int nvalue;
int i = 0;
while (i < databyte)
{
if (*data != '\r' && *data != '\n')
{
nvalue = decodetable[*data ] << 18;
nvalue = decodetable[*data ] << 12;
strdecode = (nvalue & 0x00ff0000) >> 16;
outbyte ;
if (*data != '=')
{
nvalue = decodetable[*data ] << 6;
strdecode = (nvalue & 0x0000ff00) >> 8;
outbyte ;
if (*data != '=')
{
nvalue = decodetable[*data ];
strdecode = nvalue & 0x000000ff;
outbyte ;
}
}
i = 4;
}
else// 回车换行,跳过
{
data ;
i ;
}
}
return strdecode;
}
调用示例：
int main()
{
zbase64 base64;
int datalen(0);
const unsigned char data[] = "hello zbase64";
string imgbase64 = base64.encode(data,sizeof(data));
cout << "imgbase64: " << imgbase64 << endl;
string strcode = base64.decode(imgbase64.c_str(), imgbase64.size(), datalen);
cout << "strcode: " << strcode << endl;
return 0;
}
结果输出：
imgbase64: sgvsbg8gwkjhc2u2naa=
strcode: hello zbase64