与Web交互可用的图片Base64编码

#ifndef ___BASE64_H___
#define ___BASE64_H___

#include <string>

using namespace std;

class CBase64
{
public:
    CBase64();
    ~CBase64();

    /*********************************************************
    * 函数说明：将输入数据进行base64编码
    * 参数说明：[in]pIn        需要进行编码的数据
                [in]uInLen  输入参数的字节数
                [out]strOut 输出的进行base64编码之后的字符串
    * 返回值  ：true处理成功,false失败
    **********************************************************/
    bool static Encode(const unsigned char *pIn, unsigned long uInLen, string& strOut);

    /*********************************************************
    * 函数说明：将输入数据进行base64编码
    * 参数说明：[in]pIn            需要进行编码的数据
                [in]uInLen        输入参数的字节数
                [out]pOut        输出的进行base64编码之后的字符串
                [out]uOutLen    输出的进行base64编码之后的字符串长度
    * 返回值  ：true处理成功,false失败
    **********************************************************/
    bool static Encode(const unsigned char *pIn, unsigned long uInLen, unsigned char *pOut, unsigned long *uOutLen);

    /*********************************************************
    * 函数说明：将输入数据进行base64解码
    * 参数说明：[in]strIn        需要进行解码的数据
                [out]pOut        输出解码之后的节数数据
                [out]uOutLen    输出的解码之后的字节数长度
    * 返回值  ：true处理成功,false失败
    **********************************************************/
    bool static Decode(const string& strIn, unsigned char *pOut, unsigned long *uOutLen) ;

    /*********************************************************
    * 函数说明：将输入数据进行base64解码
    * 参数说明：[in]strIn        需要进行解码的数据
                [out]pOut        输出解码之后的节数数据
                [out]uOutLen    输出的解码之后的字节数长度
    * 返回值  ：true处理成功,false失败
    **********************************************************/
    bool static Decode(const unsigned char *pIn, unsigned long uInLen, unsigned char *pOut, unsigned long *uOutLen) ;
};

#endif // ___BASE64_H___

#include "stdafx.h"

/*
 *
 *Base64?
 *
 *
 *
*/

#include "Base64.h"

static const char *g_pCodes =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

static const unsigned char g_pMap[] =
{
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , ,  , , , ,  ,
     ,  ,  ,  ,  ,  ,  ,  ,  ,  , , ,
    , , , , ,   ,   ,   ,   ,   ,   ,   ,
      ,   ,   ,  ,  ,  ,  ,  ,  ,  ,  ,  ,
     ,  ,  ,  ,  ,  ,  , , , , , ,
    ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,
     ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,
     ,  ,  , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , , , , , , , , , , ,
    , , ,
};

CBase64::CBase64()
{
}

CBase64::~CBase64()
{
}

bool CBase64::Encode(const unsigned char *pIn, unsigned long uInLen, unsigned char *pOut, unsigned long *uOutLen)
{
    unsigned long i, len2, leven;
    unsigned char *p;

    if(pOut == NULL || *uOutLen == )
        return false;

    //ASSERT((pIn != NULL) && (uInLen != 0) && (pOut != NULL) && (uOutLen != NULL));

    len2 = ((uInLen + ) / ) << ;
    if((*uOutLen) < (len2 + )) return false;

    p = pOut;
    leven =  * (uInLen / );
    for(i = ; i < leven; i += )
    {
        *p++ = g_pCodes[pIn[] >> ];
        *p++ = g_pCodes[((pIn[] & ) << ) + (pIn[] >> )];
        *p++ = g_pCodes[((pIn[] & 0xf) << ) + (pIn[] >> )];
        *p++ = g_pCodes[pIn[] & 0x3f];
        pIn += ;
    }

    if (i < uInLen)
    {
        unsigned char a = pIn[];
        unsigned char b = ((i + ) < uInLen) ? pIn[] : ;
        unsigned char c = ;

        *p++ = g_pCodes[a >> ];
        *p++ = g_pCodes[((a & ) << ) + (b >> )];
        *p++ = ((i + ) < uInLen) ? g_pCodes[((b & 0xf) << ) + (c >> )] : '=';
        *p++ = '=';
    }

    *p = ; // Append NULL byte
    *uOutLen = p - pOut;
    return true;
}

bool CBase64::Encode(const unsigned char *pIn, unsigned long uInLen, string& strOut)
{
    unsigned long i, len2, leven;
    strOut = "";

    //ASSERT((pIn != NULL) && (uInLen != 0) && (pOut != NULL) && (uOutLen != NULL));

    len2 = ((uInLen + ) / ) << ;
    //if((*uOutLen) < (len2 + 1)) return false;

    //p = pOut;
    leven =  * (uInLen / );
    for(i = ; i < leven; i += )
    {
        strOut += g_pCodes[pIn[] >> ];
        strOut += g_pCodes[((pIn[] & ) << ) + (pIn[] >> )];
        strOut += g_pCodes[((pIn[] & 0xf) << ) + (pIn[] >> )];
        strOut += g_pCodes[pIn[] & 0x3f];
        pIn += ;
    }

    if (i < uInLen)
    {
        unsigned char a = pIn[];
        unsigned char b = ((i + ) < uInLen) ? pIn[] : ;
        unsigned char c = ;

        strOut += g_pCodes[a >> ];
        strOut += g_pCodes[((a & ) << ) + (b >> )];
        strOut += ((i + ) < uInLen) ? g_pCodes[((b & 0xf) << ) + (c >> )] : '=';
        strOut += '=';
    }

    //*p = 0; // Append NULL byte
    //*uOutLen = p - pOut;
    return true;
}

bool CBase64::Decode(const string& strIn, unsigned char *pOut, unsigned long *uOutLen)
{
    unsigned long t, x, y, z;
    unsigned char c;
    unsigned long g = ;

    //ASSERT((pIn != NULL) && (uInLen != 0) && (pOut != NULL) && (uOutLen != NULL));

    for(x = y = z = t = ; x < strIn.length(); x++)
    {
        c = g_pMap[strIn[x]];
        if(c == ) continue;
        if(c == ) { c = ; g--; }

        t = (t << ) | c;

        if(++y == )
        {
            if((z + g) > *uOutLen) { return false; } // Buffer overflow
            pOut[z++] = (unsigned char)((t>>)&);
            if(g > ) pOut[z++] = (unsigned char)((t>>)&);
            if(g > ) pOut[z++] = (unsigned char)(t&);
            y = t = ;
        }
    }

    *uOutLen = z;
    return true;
}