Base64Encoder.cpp

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/*
 *  Copyright (c) 2014, Oculus VR, Inc.
 *  All rights reserved.
 *
 *  This source code is licensed under the BSD-style license found in the
 *  RakNet License.txt file in the licenses directory of this source tree. An additional grant 
 *  of patent rights can be found in the RakNet Patents.txt file in the same directory.
 *
 *
 *  Modified work: Copyright (c) 2017, SLikeSoft UG (haftungsbeschränkt)
 *
 *  This source code was modified by SLikeSoft. Modifications are licensed under the MIT-style
 *  license found in the license.txt file in the root directory of this source tree.
 */

#include "slikenet/Base64Encoder.h"
#include "slikenet/memoryoverride.h"

const char *Base64Map(void) {return "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";}
const char *base64Map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

// 3/17/2013 must be unsigned char or else it will use negative indices
int Base64Encoding(const unsigned char *inputData, int dataLength, char *outputData)
{
    // http://en.wikipedia.org/wiki/Base64

    int outputOffset, charCount;
    int write3Count;
    outputOffset=0;
    charCount=0;
    int j;

    write3Count=dataLength/3;
    for (j=0; j < write3Count; j++)
    {
        // 6 leftmost bits from first byte, shifted to bits 7,8 are 0
        outputData[outputOffset++]=base64Map[inputData[j*3+0] >> 2];
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}

        // Remaining 2 bits from first byte, placed in position, and 4 high bits from the second byte, masked to ignore bits 7,8
        outputData[outputOffset++]=base64Map[((inputData[j*3+0] << 4) | (inputData[j*3+1] >> 4)) & 63];
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}

        // 4 low bits from the second byte and the two high bits from the third byte, masked to ignore bits 7,8
        outputData[outputOffset++]=base64Map[((inputData[j*3+1] << 2) | (inputData[j*3+2] >> 6)) & 63]; // Third 6 bits
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}

        // Last 6 bits from the third byte, masked to ignore bits 7,8
        outputData[outputOffset++]=base64Map[inputData[j*3+2] & 63];
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}
    }

    if (dataLength % 3==1)
    {
        // One input byte remaining
        outputData[outputOffset++]=base64Map[inputData[j*3+0] >> 2];
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}

        // Remaining 2 bits from first byte, placed in position, and 4 high bits from the second byte, masked to ignore bits 7,8
        outputData[outputOffset++]=base64Map[((inputData[j*3+0] << 4) | (inputData[j*3+1] >> 4)) & 63];
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}

        // Pad with two equals
        outputData[outputOffset++]='=';
        outputData[outputOffset++]='=';
    }
    else if (dataLength % 3==2)
    {
        // Two input bytes remaining

        // 6 leftmost bits from first byte, shifted to bits 7,8 are 0
        outputData[outputOffset++]=base64Map[inputData[j*3+0] >> 2];
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}

        // Remaining 2 bits from first byte, placed in position, and 4 high bits from the second byte, masked to ignore bits 7,8
        outputData[outputOffset++]=base64Map[((inputData[j*3+0] << 4) | (inputData[j*3+1] >> 4)) & 63];
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}

        // 4 low bits from the second byte, followed by 00
        outputData[outputOffset++]=base64Map[(inputData[j*3+1] << 2) & 63]; // Third 6 bits
        if ((++charCount % 76)==0) {outputData[outputOffset++]='\r'; outputData[outputOffset++]='\n'; charCount=0;}

        // Pad with one equal
        outputData[outputOffset++]='=';
        //outputData[outputOffset++]='=';
    }

    // Append \r\n
    outputData[outputOffset++]='\r';
    outputData[outputOffset++]='\n';
    outputData[outputOffset]=0;

    return outputOffset;
}

int Base64Encoding(const unsigned char *inputData, int dataLength, char **outputData)
{
    *outputData = (char*) rakMalloc_Ex(dataLength * 2 + 6, _FILE_AND_LINE_);
    return Base64Encoding(inputData, dataLength, *outputData);
}