win api 实现 base64编码、解码

最近在写小玩意，用到了base64编码，但是考虑到体积大小，网上的多种实现都是利用开源的代码，这就增加了其大小。我想win api能不能实现base64编码、解码。通过一通乱搜，还有收获。就有了以下代码

#pragma comment(lib,"crypt32.lib")
 
LPSTR Base64Encode(LPBYTE lpBuffer,DWORD dwLen)
{
    DWORD dwNeed;
    LPSTR lpBase64Str ;
    DWORD dwIndex ;
    DWORD dwIndexJ;
    dwNeed = 0;
    lpBase64Str = NULL ;
     
    CryptBinaryToStringA(lpBuffer,dwLen,CRYPT_STRING_BASE64,NULL,&dwNeed);
 
    if (dwNeed)
    {
        lpBase64Str = (LPSTR)malloc(dwNeed);
        ZeroMemory(lpBase64Str,dwNeed);
        CryptBinaryToStringA(lpBuffer,dwLen,CRYPT_STRING_BASE64,lpBase64Str,&dwNeed);
        dwIndex = 0;
        while(*(lpBase64Str+dwIndex)!=0)
        {
            if (*(lpBase64Str+dwIndex) == 0x0d || *(lpBase64Str+dwIndex)==0x0a)
            {
                dwIndexJ = dwIndex +1;
                 
                while (*(lpBase64Str+dwIndexJ)!=0)
                {
                    *(lpBase64Str+dwIndexJ-1)= *(lpBase64Str+dwIndexJ);
                    dwIndexJ ++ ;
                }
 
                *(lpBase64Str+dwIndexJ-1) = 0 ;
                 
            }else
            {
                dwIndex ++ ;
            }
             
        }
    }
 
    return lpBase64Str ;
}
 
LPBYTE Base64Decode(LPSTR lpBase64Str,LPDWORD lpdwLen)
{
    DWORD dwLen ;
    DWORD dwNeed ;
    LPBYTE lpBuffer ;
 
    dwLen = strlen(lpBase64Str);
    dwNeed = 0;
    CryptStringToBinaryA(lpBase64Str,0,CRYPT_STRING_BASE64,NULL,&dwNeed,NULL,NULL);
    if (dwNeed)
    {
        lpBuffer = (LPBYTE)malloc(dwNeed);
        CryptStringToBinaryA(lpBase64Str,0,CRYPT_STRING_BASE64,lpBuffer,&dwNeed,NULL,NULL);
        *lpdwLen = dwNeed ;
    }
     
    return lpBuffer ;
}