O3客户端教学实验

1、实验目的操作系统，windows xp home edition版本Vc+ 6.0编译器接入互联网实验目的理解POP3协议原理，对邮件接收信息内容进行分析，熟悉SOCKET编程，来实现POP3客户端。实验内容实现一个简单的POP3客户端。连接POP3服务器.实现命令：USER,PASS,STAT,LIST,RETR,DELE,QUIT。3接收邮箱所有邮件4邮件进行分析，解析出：主题，发件人，发件时间，发件内容。5对个部分内容进行传输编码的解码，根据传输编码，进行base64解码或Quoted-Printable的解码6进行编码转换，将邮件原编码UTF8,GBK或7bit等转换为GBK，可以正确

2、在本机上显示程序运行在实验的时候，对和进行了测试，以下是对服务器，用户pop3client，密码123456的演示（通过选取下拉框中的主题切换邮件）登录界面：显示界面：点击删除按钮：程序实现程序结构base64_dequoted.h :存放对base64和quoted的解码函数1int DecodeQuoted(const char* pSrc, unsigned char* pDst, int nSrcLen)/对quoted传输编码进行解码2void Decode(const char *szCoded, BYTE *pOut) /对base64传输编码进行解码StructInfo.h:

3、根据邮件的格式，设计的一个结构体struct MailInfoCString m_Subject;/邮件的主题CString s_Time; /邮件发送时间CString s_Person; /邮件的发送人CString m_Contex; /邮件的内容CString m_Code; /邮件的编码;PopClient.cpp: 存放对pop3的命令操作：USER,PASS,STAT,LIST,RETR,DELE,QUITbool ConToServer(const char* sName)/连接pop3服务器,sName为pop3服务器名字或者ip;bool LoginToServer(con

4、st char *uName,const char *uPass)/登陆POP3服务器，用户名为uName,用户密码为uName;bool RecvFromServer(vector &m_Info) /从POP3服务器获取邮件信息,将信息存储在容器m_Info中;bool DeleteFromServer(int index) /从POP3服务器删除某个邮件,index指定删除邮件的标示号bool QuitFromServer() /从pop3服务器退出int RecvData(void *pData, int nLen) /接收nLen长度的流，在接收大数据量邮件的时候，需要循环读取流vo

5、id StringToStruct(const char * msgBuf,MailInfo &mailInfo) /将获取的邮件字符串流，转换到对应的结构体mailInfo中，便于以后显示和操作int GetContent(char *destStr,CString &dStr,CString code) /获取邮件正文进行传输编码解码，并将编码转换为GBK，存储在dStr中，code为正文的编码int GetGBKSubject(char *destStr,CString &dStr) /将destStr进行qp或base64解码后，转换为GBK，存储于dStr中int GetAdress

6、(char *destStr,CString &dStr) /找出邮箱的地址，为之间的内容，或者直接为“From:”后面的值,存储于dStr中LoginDlg.cpp: 用于登录对话框，接收用户输入的pop3服务器地址，用户名和密码，调用PopClient.cpp中的函数连接服务器，登录服务器PClientDlg.cpp:用于显示邮件的主题，时间，发件人，内容等信息的对话框，还可以进行删除操作和退出操作。连接服务器采用流方式tcp创建socket,可以根据服务器名（如）或者服务器IP（如sina的pop3的ip: 42）,服务器端口号110; 服务器返回+OK 表示成功；/*采用tcp传输*/

7、 pClient = socket(AF_INET,SOCK_STREAM,0); /*设置POP3服务器的IP以及地址信息*/SOCKADDR_IN pServerAddr; /存储pop3服务器的地址和端口pServerAddr.sin_family = AF_INET; pServerAddr.sin_port = htons(110); /服务器端口为110pServerAddr.sin_addr.s_addr = inet_addr(sName);if (pServerAddr.sin_addr.s_addr = INADDR_NONE)HOSTENT *hostInfo; /存储服

8、务器地址信息hostInfo = gethostbyname(sName); pServerAddr.sin_addr.s_addr = *(unsigned long *)hostInfo-h_addr); /服务器IP地址int ret; /记录函数执行返回值/*连接POP3服务器*/ret = connect(pClient,(SOCKADDR *)&pServerAddr,sizeof(SOCKADDR);if (ret = SOCKET_ERROR)return false;char msgBuf501; /存储服务器返回信息int msgLen; /存储服务器返回信息长度msgLe

9、n = recv(pClient,msgBuf,500,0);if (msgLen = SOCKET_ERROR | msgLen = 0)return false;msgBufmsgLen = 0;if (strncmp(msgBuf,+OK,3) != 0) /服务器返回非+OK表示连接失败return false;return true;登录服务器根据用户输入的用户名和密码，分别向服务器发送USER xxxrn, PASS xxxrn,服务器返回+OK 表示成功char msgBuf501; /用于存储发送和接受字符串int ret; /记录函数执行返回值int msgLen; /发送或

10、接受字符串长度/发送用户名给服务器msgBuf0 = 0;strcat(msgBuf,USER );strcat(msgBuf,uName);strcat(msgBuf,rn);ret = send(pClient,msgBuf,strlen(msgBuf),0);if (ret = SOCKET_ERROR | ret = 0)return false;/接收服务器返回信息msgLen = recv(pClient,msgBuf,500,0);if (msgLen = SOCKET_ERROR | msgLen = 0)return false;msgBufmsgLen = 0;if (st

11、rncmp(msgBuf,+OK,3) != 0) /服务器返回非+OK表示用户名发送成功return false;/发送用户密码给服务器msgBuf0 = 0;strcat(msgBuf,PASS );strcat(msgBuf,uPass);strcat(msgBuf,rn);ret = send(pClient,msgBuf,strlen(msgBuf),0);if (ret = SOCKET_ERROR | ret = 0)return false;/接收服务器返回信息msgLen = recv(pClient,msgBuf,500,0);if (msgLen = SOCKET_ERR

12、OR | msgLen = 0)return false;msgBufmsgLen = 0;if (strncmp(msgBuf,+OK,3) != 0) /服务器返回非+OK表示用户登录失败return false;return true;接收邮件首先向服务器发送STAT命令，获取邮件的个数mCount，然后根据mCount的个数循环从pop3服务器获取邮件；首先用LIST x命令获取x邮件的大小，然后根据大小接收此邮件，并将其存储于mailInfo结构体char msgBuf501; /用于存储发送和接受字符串int ret; /记录函数执行返回值int msgLen; /发送或接受字符串

13、长度m_Info.clear();/向服务器发送请求邮箱信息strcpy(msgBuf,STATrn);ret = send(pClient,msgBuf,strlen(msgBuf),0);if (ret = SOCKET_ERROR | ret = 0)return false;/接收服务器返回的邮箱信息msgLen = recv(pClient,msgBuf,500,0);if (msgLen = SOCKET_ERROR | msgLen = 0)return false;if (strncmp(msgBuf,+OK,3) != 0) /服务器返回非+OK表示用户请求失败return

14、false;msgBufmsgLen = 0;int mCount; /记录邮件的个数int sMail; /记录邮件的长度sscanf(msgBuf,+OK %d %d,&mCount,&sMail);for (int i = 1; i = mCount; i+)/向服务器发送邮件i信息的请求sprintf(msgBuf,LIST %drn,i);ret = send(pClient,msgBuf,strlen(msgBuf),0);if (ret = SOCKET_ERROR | ret = 0)return false;/接收服务器返回的信息msgLen = recv(pClient,m

15、sgBuf,500,0);if (msgLen = SOCKET_ERROR | msgLen = 0)return false;if (strncmp(msgBuf,+OK,3) != 0) /服务器返回非+OK表示用户请求失败return false;msgBufmsgLen = 0;int iFlag; /获取邮箱标示 sscanf(msgBuf,+OK %d %d,&iFlag,&sMail);/请求接收邮箱i的内容sprintf(msgBuf,RETR %drn,i);ret = send(pClient,msgBuf,strlen(msgBuf),0);if (ret = SOCK

16、ET_ERROR | ret = 0)return false;/接收服务器返回的信息msgLen = recv(pClient,msgBuf,6,0);if (msgLen = SOCKET_ERROR | msgLen = 0)return false;if (strncmp(msgBuf,+OK,3) != 0) /服务器返回非+OK表示用户请求失败return false;char * mailBuff = new char sMail+15; /用于接收邮件内容msgLen = RecvData(mailBuff,sMail+14);if (msgLen = SOCKET_ERROR

17、 | msgLen = 0)return false;mailBuffmsgLen = 0;MailInfo mailInfo;StringToStruct(mailBuff,mailInfo);m_Info.push_back(mailInfo);delete mailBuff;return true;删除邮件向服务器发送DELE x命令，删除邮件x，但是要在执行QUIT命令后才真正的删除邮件char msgBuf501; /用于存储删除字符串和接收字符串int ret; /记录函数执行返回值int msgLen; /发送或接受字符串长度/向服务器发送请求邮箱信息sprintf(msgBuf

18、,DELE %drn,index);ret = send(pClient,msgBuf,strlen(msgBuf),0);if (ret = SOCKET_ERROR | ret = 0)return false;/接收服务器返回的邮箱信息msgLen = recv(pClient,msgBuf,500,0);if (msgLen = SOCKET_ERROR | msgLen = 0)return false;if (strncmp(msgBuf,+OK,3) != 0) /服务器返回非+OK表示用户请求失败return false;msgBufmsgLen = 0;return true

19、;退出登录的pop3服务器向服务器发送QUIT命令char msgBuf501; /用于存储退出字符串和接收字符串int ret; /记录函数执行返回值int msgLen; /发送或接受字符串长度/向服务器发送请求邮箱信息sprintf(msgBuf,QUITrn);ret = send(pClient,msgBuf,strlen(msgBuf),0);if (ret = SOCKET_ERROR | ret = 0)return false;/接收服务器返回的邮箱信息msgLen = recv(pClient,msgBuf,500,0);if (msgLen = SOCKET_ERROR

20、| msgLen = 0)return false;if (strncmp(msgBuf,+OK,3) != 0) /服务器返回非+OK表示用户请求失败return false;msgBufmsgLen = 0;return true;quoted解码 int nDstLen; / 输出的字符计数 int i; i = 0; nDstLen = 0; while (i nSrcLen) if (strncmp(pSrc, =rn, 3) = 0) / 软回车，跳过 pSrc += 3; i += 3; else if (*pSrc = =) / 是编码字节 if (!strncmp(pSrc,

21、 =A8, 3)int sd = 5; sscanf(pSrc, =%02X, pDst); pDst+; pSrc += 3; i += 3; else / 非编码字节 *pDst+ = (unsigned char)*pSrc+; i+; nDstLen+; / 输出加个结束符 *pDst = 0;return nDstLen;base64解码short nDecTab256;short i;UINT buf;int nOffset, len = strlen(szCoded);char *p = (char *)szCoded; BYTE *r = pOut;memset(nDecTab, -1, sizeof(short) * 256);for(i = 0; i 3 * 8if(p + 4 - szCoded = len)buf = (nDecTab*p & 0 x3F) 18) | (nDecTab*(p + 1) & 0 x3