📄 mailcoder.cpp
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/*
*
* 编码类的实现
* 作者 Tintin Tintin2000@263.net
* 日期 2001-4-15
* 最后修改 2001-4-19
*
*/
#include "MailCoder.h"
//编码时候的每行的长度
unsigned int CMailCoder::m_LineWidth = 76;
//------------------------------------------------------------------------------
//Base64解码表
const char CMailCoder::BASE64_ENCODE_TABLE[64] = {
65, 66, 67, 68, 69, 70, 71, 72, // 00 - 07
73, 74, 75, 76, 77, 78, 79, 80, // 08 - 15
81, 82, 83, 84, 85, 86, 87, 88, // 16 - 23
89, 90, 97, 98, 99, 100, 101, 102, // 24 - 31
103, 104, 105, 106, 107, 108, 109, 110, // 32 - 39
111, 112, 113, 114, 115, 116, 117, 118, // 40 - 47
119, 120, 121, 122, 48, 49, 50, 51, // 48 - 55
52, 53, 54, 55, 56, 57, 43, 47 };// 56 - 63
//Base64编码表
const unsigned int CMailCoder::BASE64_DECODE_TABLE[256] = {
255, 255, 255, 255, 255, 255, 255, 255, // 00 - 07
255, 255, 255, 255, 255, 255, 255, 255, // 08 - 15
255, 255, 255, 255, 255, 255, 255, 255, // 16 - 23
255, 255, 255, 255, 255, 255, 255, 255, // 24 - 31
255, 255, 255, 255, 255, 255, 255, 255, // 32 - 39
255, 255, 255, 62, 255, 255, 255, 63, // 40 - 47
52, 53, 54, 55, 56, 57, 58, 59, // 48 - 55
60, 61, 255, 255, 255, 255, 255, 255, // 56 - 63
255, 0, 1, 2, 3, 4, 5, 6, // 64 - 71
7, 8, 9, 10, 11, 12, 13, 14, // 72 - 79
15, 16, 17, 18, 19, 20, 21, 22, // 80 - 87
23, 24, 25, 255, 255, 255, 255, 255, // 88 - 95
255, 26, 27, 28, 29, 30, 31, 32, // 96 - 103
33, 34, 35, 36, 37, 38, 39, 40, // 104 - 111
41, 42, 43, 44, 45, 46, 47, 48, // 112 - 119
49, 50, 51, 255, 255, 255, 255, 255, // 120 - 127
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255 };
//------------------------------------------------------------------------------
//Quoted编码表
const unsigned char CMailCoder::QUOTED_ENCODE_TABLE[256] = {
255, 255, 255, 255, 255, 255, 255, 255, // 00 - 07
255, 255, 10, 255, 255, 13, 255, 255, // 08 - 15
255, 255, 255, 255, 255, 255, 255, 255, // 16 - 23
255, 255, 255, 255, 255, 255, 255, 255, // 24 - 31
255, 33, 34, 35, 36, 37, 38, 39,
40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, 52, 53, 54, 55,
56, 57, 58, 59, 60, 255, 62, 63,
64, 65, 66, 67, 68, 69, 70, 71,
72, 73, 74, 75, 76, 77, 78, 79,
80, 81, 82, 83, 84, 85, 86, 87,
88, 89, 90, 91, 92, 93, 94, 95,
96, 97, 98, 99, 100, 101, 102, 103,
104, 105, 106, 107, 108, 109, 110, 111,
112, 113, 114, 115, 116, 117, 118, 119,
120, 121, 122, 123, 124, 125, 126, 127,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255 };
//------------------------------------------------------------------------------
//获取Base64编码长度
int CMailCoder::Base64EncodeSize(int iSize)
{
int nSize, nCR;
nSize = (iSize + 2) / 3 * 4 ;
nCR = nSize / m_LineWidth; //计算回车数量
nSize+= nCR * 2;
return nSize;
}
//------------------------------------------------------------------------------
//获取Base64解码长度
int CMailCoder::Base64DecodeSize(int iSize)
{
return (iSize + 3) / 4 * 3;
}
//------------------------------------------------------------------------------
//获取UUCode编码长度
int CMailCoder::UUEncodeSize(int iSize)
{
int nSize, nCR;
nSize = (iSize + 2) / 3 * 4 ;
nCR = nSize / m_LineWidth + 2; //计算回车数量
nSize+= nCR * 3 + 2;
return nSize;
}
//------------------------------------------------------------------------------
//获取UUCode解码长度
int CMailCoder::UUDecodeSize(int iSize)
{
return (iSize + 3) / 4 * 3;
}
//------------------------------------------------------------------------------
//获取Quoted编码长度
int CMailCoder::QuotedEncodeSize(int iSize)
{
int nSize = iSize * 3 + 1;
int nCR = nSize / m_LineWidth;
nSize+= nCR * 3;
return nSize;
}
//------------------------------------------------------------------------------
//Base64编码
int CMailCoder::base64_encode(char *pSrc, unsigned int nSize, char *pDest)
{
if ((pSrc == NULL) || (nSize <= 0)) return 0;
unsigned int iB, iInMax3, Len;
char *pInPtr, *pInLimitPtr;
char *OutPtr ;
pInPtr = pSrc;
iInMax3 = nSize / 3 * 3;
OutPtr = pDest;
pInLimitPtr = pInPtr + iInMax3;
while (pInPtr != pInLimitPtr)
{
Len = 0;
while ((Len < m_LineWidth) && (pInPtr != pInLimitPtr))
{
iB = (unsigned char) *pInPtr++;
iB = iB << 8;
iB = iB | (unsigned char) *pInPtr++;
iB = iB << 8;
iB = iB | (unsigned char) *pInPtr++;
//以4 byte倒序写入输出缓冲
OutPtr[3] = BASE64_ENCODE_TABLE[iB & 0x3F];
iB = iB >> 6;
OutPtr[2] = BASE64_ENCODE_TABLE[iB & 0x3F];
iB = iB >> 6;
OutPtr[1] = BASE64_ENCODE_TABLE[iB & 0x3F];
iB = iB >> 6;
OutPtr[0] = BASE64_ENCODE_TABLE[iB];
OutPtr+=4;
Len+=4;
}
if (Len >= m_LineWidth)
{
*OutPtr++ = '\r'; //加上回车换行符
*OutPtr++ = '\n';
}
}
//设置尾部
switch (nSize - iInMax3)
{
case 1:
iB = (unsigned char) *pInPtr;
iB = iB << 4;
OutPtr[1] = BASE64_ENCODE_TABLE[iB & 0x3F];
iB = iB >> 6;
OutPtr[0] = BASE64_ENCODE_TABLE[iB];
OutPtr[2] = '='; //用'='也就是64码填充剩余部分
OutPtr[3] = '=';
OutPtr+=4;
break;
case 2:
iB = (unsigned char) *pInPtr++;
iB = iB << 8;
iB = iB | (unsigned char) *pInPtr;
iB = iB << 2;
OutPtr[2] = BASE64_ENCODE_TABLE[iB & 0x3F];
iB = iB >> 6;
OutPtr[1] = BASE64_ENCODE_TABLE[iB & 0x3F];
iB = iB >> 6;
OutPtr[0] = BASE64_ENCODE_TABLE[iB];
OutPtr[3] = '='; // Fill remaining byte.
OutPtr+=4;
break;
}
return (unsigned int) (OutPtr - pDest);
}
//------------------------------------------------------------------------------
//Base64解码
int CMailCoder::base64_decode(char *pSrc, unsigned int nSize, char *pDest)
{
if ((pSrc == NULL) || (pDest == NULL) || (nSize <= 0)) return 0;
unsigned int lByteBuffer, lByteBufferSpace;
unsigned int C; //临时阅读变量
int reallen;
char *InPtr, *InLimitPtr;
char *OutPtr;
lByteBuffer = 0; lByteBufferSpace = 4;
InPtr = pSrc;
InLimitPtr= InPtr + nSize;
OutPtr = pDest;
while (InPtr != InLimitPtr)
{
C = BASE64_DECODE_TABLE[*InPtr]; // Read from InputBuffer.
InPtr++;
if (C == 0xFF) continue; //读到255非法字符
lByteBuffer = lByteBuffer << 6 ;
lByteBuffer = lByteBuffer | C ;
lByteBufferSpace--;
if (lByteBufferSpace != 0) continue; //一次读入4个字节
//到序写入3个字节到缓冲
OutPtr[2] = lByteBuffer;
lByteBuffer = lByteBuffer >> 8;
OutPtr[1] = lByteBuffer;
lByteBuffer = lByteBuffer >> 8;
OutPtr[0] = lByteBuffer;
//准备写入后3位
OutPtr+= 3; lByteBuffer = 0; lByteBufferSpace = 4;
}
reallen = (unsigned int)OutPtr - (unsigned int)pDest;
//处理尾部 返回实际长度
switch (lByteBufferSpace)
{
case 1:
lByteBuffer = lByteBuffer >> 2;
OutPtr[1] = lByteBuffer;
lByteBuffer = lByteBuffer >> 8;
OutPtr[0] = lByteBuffer;
return reallen + 2;
case 2:
lByteBuffer = lByteBuffer >> 4;
OutPtr[0] = lByteBuffer;
return reallen + 1;
default:
return reallen;
}
}
//------------------------------------------------------------------------------
//UUCode编码
int CMailCoder::UU_encode(char *pSrc, unsigned int nSize, char *pDest)
{
if ((pSrc == NULL) || (pDest == NULL) || (nSize <= 0)) return 0;
unsigned int lByteBufferSpace, Len;
unsigned char B[3]; //临时阅读变量
char *InPtr, *InLimitPtr;
char *OutPtr;
InPtr = pSrc;
InLimitPtr= InPtr + nSize;
OutPtr = pDest;
while (InPtr < InLimitPtr)
{
Len = 0;
while ((InPtr < InLimitPtr) && (Len < m_LineWidth))
{
lByteBufferSpace = (unsigned int) InLimitPtr - (unsigned int) InPtr;
if (lByteBufferSpace > 3) lByteBufferSpace = 3; //设置步长
//取值
for (unsigned int i = 0; i < lByteBufferSpace; i++ )
{
B[i] = *InPtr++;
}
if (Len == 0)
{
*OutPtr++ = 'M';
Len++;
}
//编码运算
OutPtr[0] = B[0] >> 2;
OutPtr[1] = (unsigned int) (B[0] << 4 & 0x30) + (unsigned int) (B[1] >> 4 & 0x0F);
OutPtr[2] = (unsigned int) (B[1] << 2 & 0x3C) + (unsigned int) (B[2] >> 6 & 0x03);
OutPtr[3] = B[2] & 0x3F;
for (i = 0; i < 4; i++)
{
if (OutPtr[i] == NULL)
OutPtr[i] = '`';//(unsigned char) (OutPtr[i] + 0x60);
else
OutPtr[i] = ' ' + OutPtr[i];//(unsigned char) (OutPtr[i] + 0x20);
}
OutPtr+=4;
Len+=4;
}
*OutPtr++ = '\r'; //设置回车
*OutPtr++ = '\n';
}
return (unsigned int) (OutPtr - pDest);
}
//------------------------------------------------------------------------------
//UUCode解码
int CMailCoder::UU_decode(char *pSrc, unsigned int nSize, char *pDest)
{
char C[4]; //临时阅读变量
char Tmp;
int CurrIndex, Index;
char *InPtr, *InLimitPtr;
char *OutPtr;
if ((pSrc == NULL) || (pDest == NULL) || (nSize <= 0)) return 0;
CurrIndex = 0;
InPtr = pSrc;
InLimitPtr= InPtr + nSize;
OutPtr = pDest;
while (InPtr != InLimitPtr) //读取4个字符
{
memset(C, 0, sizeof(C));
Index = 0;
do
{
Tmp = *InPtr++;
if (Tmp == 0x60)
{
Tmp = 0x20; //为了兼容OutLook Express
}
else if (Tmp =='\r') //首个字母不处理
{
InPtr++;
CurrIndex = 0;
}
if ((Tmp > 0x20) || ( CurrIndex > 0 ))
{
Tmp = Tmp - 0x20;
if (CurrIndex == 0)
{
CurrIndex = Tmp;
}
else
{
C[Index] = Tmp; // 向数组中追加字符
Index++;
}
}
}
while ((InPtr < InLimitPtr) && (Index < sizeof(C)));
OutPtr[0] = (char) ((C[0] << 2) + (C[1] >> 4));
OutPtr[1] = (char) ((C[1] << 4) + (C[2] >> 2));
OutPtr[2] = (char) ((C[2] << 6) + C[3]);
OutPtr+=3; //设置起始位置
}
return (unsigned int)OutPtr - (unsigned int)pDest;
}
//------------------------------------------------------------------------------
//Quoted编码
int CMailCoder::quoted_encode(char *pSrc, unsigned int nSize, char *pDest)
{
unsigned int Len;
unsigned char B; //临时阅读变量
char *InPtr, *InLimitPtr;
char *OutPtr;
if ((pSrc == NULL) || (pDest == NULL) || (nSize <= 0)) return 0;
InPtr = pSrc;
InLimitPtr= InPtr + nSize;
OutPtr = pDest;
while (InPtr < InLimitPtr)
{
Len = 0;
while ((InPtr < InLimitPtr) && (Len < m_LineWidth))
{
B = *InPtr++;
if (QUOTED_ENCODE_TABLE[ B ] == 255)
{
*OutPtr++ = '=';
*OutPtr++ = DecToHex(B >> 4);
*OutPtr++ = DecToHex(B & 0x0f);
Len+=3;
}
else
{
*OutPtr++ = B;
Len++;
}
}
if (Len >= m_LineWidth)
{
*OutPtr++ = '=';
*OutPtr++ = '\r'; //设置新行
*OutPtr++ = '\n';
}
}
*OutPtr = '\0';
return (unsigned int) (OutPtr - pDest);
}
//------------------------------------------------------------------------------
//Quoted解码
int CMailCoder::quoted_decode(char *pSrc, unsigned int nSize, char *pDest)
{
if ((pSrc == NULL) || (pDest == NULL) || (nSize <= 0)) return 0;
unsigned char nA, nB;
char C[2]; //临时阅读变量
char *InLimitPtr= pSrc + nSize;
char *pDestOrg = pDest;
while (pSrc < InLimitPtr)
{
C[0] = *pSrc++; //先取第一字符
if (C[0] == '=') //如果后面是经过编码的
{
C[0] = *pSrc++; //取出两个编码字符
C[1] = *pSrc++;
if (C[0] != '\r')
{
nA = HexToDec(C[0]); //解码变换
nB = HexToDec(C[1]);
*pDest++ = (nA << 4) + nB;
}
}
else //否则直接输出
{
*pDest++ = C[0];
}
}
return (unsigned int)(pDest - pDestOrg);
}
//------------------------------------------------------------------------------
//十进制-->十六进制
unsigned char CMailCoder::DecToHex( unsigned char B)
{
return B < 10 ? '0' + B:'A' + B - 10;
}
//------------------------------------------------------------------------------
//十六进制-->十进制
unsigned char CMailCoder::HexToDec( unsigned char C )
{
return C <= '9' ? C - '0' : C - 'A' + 10;
}
//------------------------------------------------------------------------------
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