#include "stdafx.h" //用别的编译器时，请确定这个头文件的去留
#include "CBase64.h"
CBase64::CBase64 ()
{
}
inline unsigned int CBase64::CalculateRecquiredEncodeOutputBufferSize (unsigned int p_InputByteCount)
{
unsigned int ret = 0;
div_t result = div (p_InputByteCount, 3);
unsigned int RecquiredBytes = 0;
if (result.rem == 0)
{
RecquiredBytes = result.quot * 4;
}
else
{
RecquiredBytes = result.quot * 4 + 4;
}
// 每隔 76 个字符 会有一个 CRLF ("\r\n")
result = div (RecquiredBytes, 76);
RecquiredBytes += result.quot * 2;
return ++RecquiredBytes; // 还需要一个字节存放 '\0'
}
// 计算解码时需要的缓冲区大小
inline unsigned int CBase64::CalculateRecquiredDecodeOutputBufferSize (char* p_pInputBufferString)
{
unsigned int ret=0; // 返回值
unsigned int BufferLength = strlen (p_pInputBufferString);
div_t result = div (BufferLength, 4);
if (p_pInputBufferString [BufferLength - 1] != '=')
ret = result.quot * 3;
else
{
if (p_pInputBufferString [BufferLength - 2] == '=')
ret = result.quot * 3 - 2;
else
ret = result.quot * 3 - 1;
}
return ++ret; // 还需要一个字节存放 '\0'
}
// 每四个一组编码
inline void CBase64::EncodeByteTriple (char* p_pInputBuffer, unsigned int InputCharacters, char* p_pOutputBuffer)
{
unsigned int mask = 0xfc000000;
unsigned int buffer = 0;
char* temp = (char*) &buffer;
temp [3] = p_pInputBuffer [0];
if (InputCharacters > 1)
temp [2] = p_pInputBuffer [1];
if (InputCharacters > 2)
temp [1] = p_pInputBuffer [2];
switch (InputCharacters)
{
case 3:
{
p_pOutputBuffer [0] = BASE64_ALPHABET [(buffer & mask) >> 26];
buffer = buffer << 6;
p_pOutputBuffer [1] = BASE64_ALPHABET [(buffer & mask) >> 26];
buffer = buffer << 6;
p_pOutputBuffer [2] = BASE64_ALPHABET [(buffer & mask) >> 26];
buffer = buffer << 6;
p_pOutputBuffer [3] = BASE64_ALPHABET [(buffer & mask) >> 26];
break;
}
case 2:
{
p_pOutputBuffer [0] = BASE64_ALPHABET [(buffer & mask) >> 26];
buffer = buffer << 6;
p_pOutputBuffer [1] = BASE64_ALPHABET [(buffer & mask) >> 26];
buffer = buffer << 6;
p_pOutputBuffer [2] = BASE64_ALPHABET [(buffer & mask) >> 26];
p_pOutputBuffer [3] = '=';
break;
}
case 1:
{
p_pOutputBuffer [0] = BASE64_ALPHABET [(buffer & mask) >> 26];
buffer = buffer << 6;
p_pOutputBuffer [1] = BASE64_ALPHABET [(buffer & mask) >> 26];
p_pOutputBuffer [2] = '=';
p_pOutputBuffer [3] = '=';
break;
}
}
}
// 每四个一组解码
inline unsigned int CBase64::DecodeByteQuartet (char* p_pInputBuffer, char* p_pOutputBuffer)
{
unsigned int buffer = 0;
if (p_pInputBuffer[3] == '=')
{
if (p_pInputBuffer[2] == '=')
{
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[0]]) << 6;
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[1]]) << 6;
buffer = buffer << 14;
char* temp = (char*) &buffer;
p_pOutputBuffer [0] = temp [3];
return 1;
}
else
{
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[0]]) << 6;
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[1]]) << 6;
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[2]]) << 6;
buffer = buffer << 8;
char* temp = (char*) &buffer;
p_pOutputBuffer [0] = temp [3];
p_pOutputBuffer [1] = temp [2];
return 2;
}
}
else
{
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[0]]) << 6;
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[1]]) << 6;
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[2]]) << 6;
buffer = (buffer | BASE64_DEALPHABET [p_pInputBuffer[3]]) << 6;
buffer = buffer << 2;
char* temp = (char*) &buffer;
p_pOutputBuffer [0] = temp [3];
p_pOutputBuffer [1] = temp [2];
p_pOutputBuffer [2] = temp [1];
return 3;
}
return -1;
}
// 编码缓冲区
void CBase64::EncodeBuffer (char* p_pInputBuffer, unsigned int p_InputBufferLength, char* p_pOutputBufferString)
{
unsigned int FinishedByteQuartetsPerLine = 0;
unsigned int InputBufferIndex = 0;
unsigned int OutputBufferIndex = 0;
memset (p_pOutputBufferString, 0, CalculateRecquiredEncodeOutputBufferSize (p_InputBufferLength));
while (InputBufferIndex < p_InputBufferLength)
{
if (p_InputBufferLength - InputBufferIndex <= 2)
{
FinishedByteQuartetsPerLine ++;
EncodeByteTriple (p_pInputBuffer + InputBufferIndex, p_InputBufferLength - InputBufferIndex, p_pOutputBufferString + OutputBufferIndex);
break;
}
else
{
FinishedByteQuartetsPerLine++;
EncodeByteTriple (p_pInputBuffer + InputBufferIndex, 3, p_pOutputBufferString + OutputBufferIndex);
InputBufferIndex += 3;
OutputBufferIndex += 4;
}
if (FinishedByteQuartetsPerLine == 19)
{
p_pOutputBufferString [OutputBufferIndex ] = '\r';
p_pOutputBufferString [OutputBufferIndex+1] = '\n';
p_pOutputBufferString += 2;
FinishedByteQuartetsPerLine = 0;
}
}
}
// 解码缓冲区
unsigned int CBase64::DecodeBuffer (char* p_pInputBufferString, char* p_pOutputBuffer)
{
unsigned int InputBufferIndex = 0;
unsigned int OutputBufferIndex = 0;
unsigned int InputBufferLength = strlen (p_pInputBufferString);
char ByteQuartet [4];
memset(p_pOutputBuffer,0,CalculateRecquiredDecodeOutputBufferSize(p_pInputBufferString));
while (InputBufferIndex < InputBufferLength)
{
for (int i = 0; i < 4; i++)
{
ByteQuartet [i] = p_pInputBufferString [InputBufferIndex];
// Ignore all characters except the ones in BASE64_ALPHABET
if ((ByteQuartet [i] >= 48 && ByteQuartet [i] <= 57) ||
(ByteQuartet [i] >= 65 && ByteQuartet [i] <= 90) ||
(ByteQuartet [i] >= 97 && ByteQuartet [i] <= 122) ||
ByteQuartet [i] == '+' || ByteQuartet [i] == '/' || ByteQuartet [i] == '=')
{
}
else
{
// 非法字符
i--;
}
InputBufferIndex++;
}
OutputBufferIndex += DecodeByteQuartet (ByteQuartet, p_pOutputBuffer + OutputBufferIndex);
}
// OutputBufferIndex gives us the next position of the next decoded character
// inside our output buffer and thus represents the number of decoded characters
// in our buffer.
return OutputBufferIndex;
}
inline unsigned int CBase64::CreateMatchingEncodingBuffer (unsigned int p_InputByteCount, char** p_ppEncodingBuffer)
{
unsigned int Size = CalculateRecquiredEncodeOutputBufferSize (p_InputByteCount);
(*p_ppEncodingBuffer) = (char*) malloc (Size);
memset (*p_ppEncodingBuffer, 0, Size);
return Size;
}
inline unsigned int CBase64::CreateMatchingDecodingBuffer (char* p_pInputBufferString, char** p_ppDecodingBuffer)
{
unsigned int Size = CalculateRecquiredDecodeOutputBufferSize (p_pInputBufferString);
(*p_ppDecodingBuffer) = (char*) mal
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