Base64 Encript/Decript (C++ Builder XE) - c++

Question

I'm need encrypt a content of strings in C++ Builder XE and found this code on the internet:
AnsiString Base64Encode(AnsiString slToEnc)
{
//The Base64 Table
const char Base64Table[64]=
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
char * buftoenc = slToEnc.c_str();
int bufsize = slToEnc.Length() + 1;
char * encbuf = new char[slToEnc.Length() * 5];
encbuf[0] = '\0'; int ilStrLen = -1;
int i=0; int b64byte[5];
unsigned char *buftemp;
AnsiString slRetVal = EmptyStr;
buftemp=(unsigned char *)malloc(bufsize+2);
strcpy(buftemp,buftoenc);
if (fmod(bufsize,3)==1)
{
buftemp[bufsize]='\0';
buftemp[bufsize+1]='\0';
}
if (fmod(bufsize,3)==2)buftemp[bufsize]='\0';
while (i<bufsize)
{
b64byte[0]=buftemp[i]>>2;
b64byte[1]=((buftemp[i]&3)<<4)|(buftemp[i+1]>>4);
b64byte[2]=((buftemp[i+1]&0x0F)<<2)|(buftemp[i+2]>>6);
b64byte[3]=buftemp[i+2]&0x3F;
encbuf[i+(i/3)]=Base64Table[b64byte[0]];
encbuf[i+(i/3)+1]=Base64Table[b64byte[1]];
encbuf[i+(i/3)+2]=Base64Table[b64byte[2]];
encbuf[i+(i/3)+3]=Base64Table[b64byte[3]];
i+=3;
}
free(buftemp);
if (fmod(bufsize,3)==0) ilStrLen = bufsize*8/6;
else if (fmod(bufsize,3)==1) ilStrLen = ((bufsize+2)*8/6)-2;
else if (fmod(bufsize,3)==2) ilStrLen = ((bufsize+1)*8/6)-1;
else ilStrLen = -1;
if(ilStrLen> 0) slRetVal = AnsiString(encbuf).SubString(1, ilStrLen);
if(encbuf != NULL) { delete encbuf; encbuf = NULL; }
return slRetVal;
}
// Calling function in a button component =>
Base64Encode(Memo1->Text);
But it generates a small erro on compilation making reference to ambiguity between the function std::fmod(double, double) being in this source code and the same function of math.h library.
Some suggestion?

Answer 1

In order to resolve the ambiguity you need to specify the namespace for the fmod function. Just change the line:
if (fmod(bufsize,3)==1)
to:
if (std::fmod(bufsize,3)==1)
and it should compile for you.

Answer 2

You can use http://docwiki.embarcadero.com/Libraries/Rio/en/System.NetEncoding.TBase64Encoding
TBase64Encoding* enc = new TBase64Encoding();
UnicodeString decoded = enc->Decode(encoded);
delete enc;
TBase64Encoding* enc = new TBase64Encoding();
UnicodeString encoded = enc->Encode(whatever);
delete enc;

Answer 3

My version is a simple fast encoder (decoder) of base64 for C++ Builder.
//---------------------------------------------------------------------------
UnicodeString __fastcall TExample::Base64Encode(void *data,int length)
{
if (length<=0) return L"";
static const char set[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
unsigned char *in=(unsigned char*)data;
char *pos,*out=pos=new char[((length-1)/3+1)<<2];
while ((length-=3)>=0)
{
pos[0]=set[in[0]>>2];
pos[1]=set[((in[0]&0x03)<<4)|(in[1]>>4)];
pos[2]=set[((in[1]&0x0F)<<2)|(in[2]>>6)];
pos[3]=set[in[2]&0x3F];
pos+=4;
in+=3;
};
if ((length&2)!=0)
{
pos[0]=set[in[0]>>2];
if ((length&1)!=0)
{
pos[1]=set[((in[0]&0x03)<<4)|(in[1]>>4)];
pos[2]=set[(in[1]&0x0F)<<2];
}
else
{
pos[1]=set[(in[0]&0x03)<<4];
pos[2]='=';
};
pos[3]='=';
pos+=4;
};
UnicodeString code=UnicodeString(out,pos-out);
delete[] out;
return code;
};
//---------------------------------------------------------------------------
int __fastcall TExample::Base64Decode(const UnicodeString &code,unsigned char **data)
{
int length;
if (((length=code.Length())==0)||((length&3)!=0)) return 0;
wchar_t *str=code.c_str();
unsigned char *pos,*out=pos=new unsigned char[(length>>2)*3];
while (*str!=0)
{
length=-1;
int shift=18,bits=0;
do
{
wchar_t s=str[++length];
if ((s>=L'A')&&(s<=L'Z')) bits|=(s-L'A')<<shift;
else if ((s>=L'a')&&(s<=L'z')) bits|=(s-(L'a'-26))<<shift;
else if (((s>=L'0')&&(s<=L'9'))) bits|=(s-(L'0'-52))<<shift;
else if (s==L'+') bits|=62<<shift;
else if (s==L'/') bits|=63<<shift;
else if (s==L'=')
{
length--;
break;
}
else
{
delete[] out;
return 0;
};
}
while ((shift-=6)>=0);
pos[0]=bits>>16;
pos[1]=bits>>8;
pos[2]=bits;
pos+=length;
str+=4;
};
*data=out;
return pos-out;
};
//---------------------------------------------------------------------------