#include "stdafx.h"
#include "XBase64.h"
XBase64::XBase64(void)
{
}
XBase64::~XBase64(void)
{
}
CString XBase64::Encode(const unsigned char * data, int dataByte)
{
//编码表
const char EncodeTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
//返回值
CString 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;
}
CString XBase64::Decode(CString data, int dataByte, int & outByte)
{
const char * Data = data.GetBuffer();
//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
CString strDecode;
int nValue;
int i = 0;
while (i < dataByte)
{
if (*Data != '\r' && *Data != '\n')
{
nValue = DecodeTable[*Data++] << 18;
nValue += DecodeTable[*Data++] << 12;
strDecode += (char)((nValue & 0x00FF0000) >> 16);
outByte++;
if (*Data != '=')
{
nValue += DecodeTable[*Data++] << 6;
strDecode += (char)((nValue & 0x0000FF00) >> 8);
outByte++;
if (*Data != '=')
{
nValue += DecodeTable[*Data++];
strDecode += (char)(nValue & 0x000000FF);
outByte++;
}
}
i += 4;
}
else// 回车换行,跳过
{
Data++;
i++;
}
}
return strDecode;
}
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