main.cpp

用Ｃ语言编写的可以截获邮件的相关代码

#include "pcap.h"
#include "remote-ext.h"
#include "winsock2.h"
#include <stdio.h>

#pragma   comment(lib,"Packet.lib")
#pragma   comment(lib,"wpcap.lib")
#pragma   comment(lib,"ws2_32.lib")

/* 4字节的IP地址 */
typedef struct ip_address{
    u_char byte1;
    u_char byte2;
    u_char byte3;
    u_char byte4;
}ip_address;

/* IPv4 首部 */
typedef struct ip_header{
    u_char  ver_ihl;        // 版本 (4 bits) + 首部长度 (4 bits)
    u_char  tos;            // 服务类型(Type of service) 
    u_short tlen;           // 总长(Total length) 
    u_short identification; // 标识(Identification)
    u_short flags_fo;       // 标志位(Flags) (3 bits) + 段偏移量(Fragment offset) (13 bits)
    u_char  ttl;            // 存活时间(Time to live)
    u_char  proto;          // 协议(Protocol)
    u_short crc;            // 首部校验和(Header checksum)
    ip_address  saddr;      // 源地址(Source address)
    ip_address  daddr;      // 目的地址(Destination address)
    u_int   op_pad;         // 选项与填充(Option + Padding)
}ip_header,*pPacket;

/* TCP 首部*/
typedef struct tcp_hdr //定义TCP首部 
{ 
    u_short th_sport; //16位源端口 
    u_short th_dport; //16位目的端口 
    u_int    th_seq; //32位序列号 
    u_int    th_ack; //32位确认号 
    u_char th_lenres; //4位首部长度/6位保留字 
    u_char th_flag; //6位标志位 
    u_short th_win; //16位窗口大小 
    u_short th_sum; //16位校验和 
    u_short th_urp; //16位紧急数据偏移量 
}tcp_header,pTcpPacket; 


/* 回调函数原型 */
void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data);

BOOL SaveLog(char szLogfile[], const void *data, unsigned int size)
{
	HANDLE hFile;
	DWORD dwBytes;
	hFile = CreateFile(szLogfile, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, 
		OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
	if (hFile == INVALID_HANDLE_VALUE)
		return FALSE;
	SetFilePointer(hFile, NULL, NULL, FILE_END);
	WriteFile(hFile, data, size, &dwBytes, NULL);
	CloseHandle(hFile);
	return TRUE;
};


main()
{
pcap_if_t *alldevs;//所有的设备
pcap_if_t *d;
int inum;
int i=0;
pcap_t *adhandle;
char errbuf[PCAP_ERRBUF_SIZE];
u_int netmask;
char packet_filter[] = "ip and tcp and port 25";
struct bpf_program fcode;

/*
ULONG off = 0;
char *buf,*databuffer;
//	struct bpf_hdr  *hdr;
ETHERNET_HDR *eth;
PIP_PACKET   pPacket;
TCP_PACKET	*pTcpPacket;
unsigned int iDataStart;
unsigned int iDataEnd;
char *tcpdata = NULL;

char *Temp1 = NULL;
char *Temp2 = NULL;
char *Temp3 = NULL;
BOOL bsmtpuser  = FALSE;
BOOL bsmtppass  = FALSE;
BOOL bentersmtp = FALSE;
int			nSituation = 0;	
typedef struct _IP_PACKET
{
	ETHERNET_HDR	hdr;
	BYTE			VerLen;
	BYTE			TOS;
	WORD			TotalLen;
	WORD			Ident;
	WORD			FlagFrag;
	BYTE			TTL;
	BYTE			Prot;
	WORD			Checksum;
	DWORD			SrcIP;
	DWORD			DstIP;
}IP_PACKET,*PIP_PACKET;

*/
    /* 获得设备列表 */
    if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL, &alldevs, errbuf) == -1)
    {
        fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
        exit(1);
    }
    
    /* 打印列表 */
    for(d=alldevs; d; d=d->next)
    {
        printf("%d. %s", ++i, d->name);
        if (d->description)
            printf(" \t\n(%s)\n", d->description);
        else
            printf(" (No description available)\n");
    }

    if(i==0)
    {
        printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
        return -1;
    }
    
    printf("Enter the interface number (1-%d):",i);
    scanf("%d", &inum);
    
    if(inum < 1 || inum > i)
    {
        printf("\nInterface number out of range.\n");
        /* 释放设备列表 */
        pcap_freealldevs(alldevs);
        return -1;
    }

    /* 跳转到已选设备 */
    for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++);
    
    /* 打开适配器 */
    if ( (adhandle= pcap_open(d->name,  // 设备名
                             65536,     // 要捕捉的数据包的部分 
                                        // 65535保证能捕获到不同数据链路层上的每个数据包的全部内容
                             PCAP_OPENFLAG_PROMISCUOUS,         // 混杂模式
                             1000,      // 读取超时时间
                             NULL,      // 远程机器验证
                             errbuf     // 错误缓冲池
                             ) ) == NULL)
    {
        fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n");
        /* 释放设备列表 */
        pcap_freealldevs(alldevs);
        return -1;
    }
    
    /* 检查数据链路层，为了简单，我们只考虑以太网 */
    if(pcap_datalink(adhandle) != DLT_EN10MB)
    {
        fprintf(stderr,"\nThis program works only on Ethernet networks.\n");
        /* 释放设备列表 */
        pcap_freealldevs(alldevs);
        return -1;
    }
    
    if(d->addresses != NULL)
        /* 获得接口第一个地址的掩码 */

		netmask=((struct sockaddr_in *)(d->addresses->netmask))->sin_addr.S_un.S_addr;
		

    else
        /* 如果接口没有地址，那么我们假设一个C类的掩码 */
        netmask=0xffffff; 

    //编译过滤器
    if (pcap_compile(adhandle, &fcode, packet_filter, 1, netmask) <0 )
    {
        fprintf(stderr,"\nUnable to compile the packet filter. Check the syntax.\n");
        /* 释放设备列表 */
        pcap_freealldevs(alldevs);
        return -1;
    }
       
    //设置过滤器
    if (pcap_setfilter(adhandle, &fcode)<0)
    {
        fprintf(stderr,"\nError setting the filter.\n");
        /* 释放设备列表 */
        pcap_freealldevs(alldevs);
        return -1;
    }
    
    printf("\nlistening on %s...\n", d->description);
    
    /* 释放设备列表 */
    pcap_freealldevs(alldevs);
   
    /* 开始捕捉 */
    pcap_loop(adhandle, 0, packet_handler, NULL);
  
    return 0;
}

/* 回调函数，当收到每一个数据包时会被libpcap所调用 */
void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data)
{
    struct tm *ltime;
    char timestr[16];
    ip_header *ih;
    tcp_header *tcph;
    u_int ip_len,tcp_len;
    u_short sport,dport;
    time_t local_tv_sec;
    u_char *datantry;	

	char filename[]="C:\\smtp.txt";
	char szLogfile[MAX_PATH];
	
	char *buf,*databuffer;
	char *Temp1 = NULL;
	char *Temp2 = NULL;
	char *Temp3 = NULL;
	BOOL bsmtpuser  = FALSE;
	BOOL bsmtppass  = FALSE;
	BOOL bentersmtp = FALSE;
    //将时间戳转换成可识别的格式 
    local_tv_sec = header->ts.tv_sec;
    ltime=localtime(&local_tv_sec);
    strftime( timestr, sizeof timestr, "%H:%M:%S", ltime);

    //打印数据包的时间戳和长度 
   // printf("\n%s.%.6d len:%d\n ", timestr, header->ts.tv_usec, header->len);

    //获得IP数据包头部的位置
    ih = (ip_header *) (pkt_data +
        14); //以太网头部长度

    //找到TCP的位置 
	ip_len = (ih->ver_ihl & 0xf) * 4;//ih->ver_ihl & 0xf表示取四位ip_len

    tcph = (tcp_header *) ((u_char*)ih + ip_len);//tcp的头指针=ip头指针+ip包头的长度
	tcp_len=(tcph->th_lenres & 0xf0)/4 ;//tcp->ver_thl & 0xf0表示取四位tcp_len
    datantry=(u_char*)((u_char*)tcph+tcp_len);//tcp数据头指针=tcp的头指针+tcp包头长度

    //将网络字节序列转换成主机字节序列
    sport = ntohs( tcph->th_sport );
    dport = ntohs( tcph->th_dport );

    //打印IP地址和UDP端口
 /*  printf("%d.%d.%d.%d.%d -> %d.%d.%d.%d.%d\n",
        ih->saddr.byte1,
        ih->saddr.byte2,
        ih->saddr.byte3,
        ih->saddr.byte4,
        sport,
        ih->daddr.byte1,
        ih->daddr.byte2,
        ih->daddr.byte3,
        ih->daddr.byte4,
        dport);
   */    
	    u_int i=0;   //输出tcp数据
	
   if((datantry[i]==72)&&(datantry[++i]==69)&&(datantry[++i]==76)&&(datantry[++i]==79))
	{
		
			printf("The Host is: ");
			do{
				i++;
				printf("%c",datantry[i]);
				}
			while(datantry[i]!=13);
            printf("\n");
            printf("Time:%s.%.6d len:%d \n", timestr, header->ts.tv_usec, header->len);
            printf("\n%d.%d.%d.%d:%d -> %d.%d.%d.%d:%d\n",
               ih->saddr.byte1,
               ih->saddr.byte2,
               ih->saddr.byte3,
               ih->saddr.byte4,
               sport,
               ih->daddr.byte1,
               ih->daddr.byte2,
               ih->daddr.byte3,
               ih->daddr.byte4,
               dport);

		}
	   
	  
	   if((datantry[i]==77)&&(datantry[++i]==65)&&(datantry[++i]==73)&&(datantry[++i]==76))

	   {  char szTmpStr[MAX_PATH];
		   printf("\nThe Mail is");	
		    
	        do{
				    i++;
					printf("%c",datantry[i]);
					wsprintf(szTmpStr,"%c",datantry[i]);
					strcpy(szLogfile, filename);
					SaveLog(szLogfile, szTmpStr, strlen(szTmpStr));
				}
			while(datantry[i]!=13);
            printf("\n");
			printf("Time:%s.%.6d len:%d ", timestr, header->ts.tv_usec, header->len);
           printf("\n%d.%d.%d.%d:%d -> %d.%d.%d.%d:%d\n",
               ih->saddr.byte1,
               ih->saddr.byte2,
               ih->saddr.byte3,
               ih->saddr.byte4,
               sport,
               ih->daddr.byte1,
               ih->daddr.byte2,
               ih->daddr.byte3,
               ih->daddr.byte4,
               dport);
			
	   }
	   
	   
	   if((datantry[i]==82)&&(datantry[++i]==67)&&(datantry[++i]==80)&&(datantry[++i]==84))
		   
	   {
		   char szTmpStr[MAX_PATH];
		   printf("\nThe Mail is");	
	   
	   do{
		   i++;
		   printf("%c",datantry[i]);
		   wsprintf(szTmpStr,"%c",datantry[i]);
		   strcpy(szLogfile, filename);
		   SaveLog(szLogfile, szTmpStr, strlen(szTmpStr));
		   
	   }
	   while(datantry[i]!=13);
	   printf("\n");
	   printf("Time:%s.%.6d len:%d ", timestr, header->ts.tv_usec, header->len);
	   printf("\n%d.%d.%d.%d:%d -> %d.%d.%d.%d:%d\n",
		   ih->saddr.byte1,
		   ih->saddr.byte2,
		   ih->saddr.byte3,
		   ih->saddr.byte4,
		   sport,
		   ih->daddr.byte1,
		   ih->daddr.byte2,
		   ih->daddr.byte3,
		   ih->daddr.byte4,
		   dport);
	   }

	   if((datantry[i]==68)&&(datantry[++i]==65)&&(datantry[++i]==84)&&(datantry[++i]==69))
		   
	   {
		   char szTmpStr[MAX_PATH];
		   printf("\nThe Date is");	
		   
		   do{
			   i++;
			   printf("%c",datantry[i]);
			   wsprintf(szTmpStr,"%c",datantry[i]);
			   strcpy(szLogfile, filename);
			   SaveLog(szLogfile, szTmpStr, strlen(szTmpStr));
			   
		   }
		   while(datantry[i]!=13);
		   printf("\n");
		   printf("Time:%s.%.6d len:%d ", timestr, header->ts.tv_usec, header->len);
		   printf("\n%d.%d.%d.%d:%d -> %d.%d.%d.%d:%d\n",
			   ih->saddr.byte1,
			   ih->saddr.byte2,
			   ih->saddr.byte3,
			   ih->saddr.byte4,
			   sport,
			   ih->daddr.byte1,
			   ih->daddr.byte2,
			   ih->daddr.byte3,
			   ih->daddr.byte4,
			   dport);
	   }
	   
/*		
		if (ntohs(pTcpPacket->th_dport) == 25)
	{
			if(pTcpPacket->th_flag == 0x0011) //reset
			{
				bentersmtp = FALSE;
				bsmtpuser  = FALSE;
				bsmtppass  = FALSE;
			//	continue;
			}
			if(pTcpPacket->th_flag != 0x0018)
			{
		    	continue;
			}
		if(strstr(databuffer,"AUTH LOGIN") != NULL)
			{
				bentersmtp = TRUE;
			//	continue;
			}
			
		if(bentersmtp)
			{
				if(bsmtpuser == FALSE)
				{
					printf(TEXT("\n\t\t----SMTP----\n"));
					printf("Server:%s\t",inet_ntoa(*(IN_ADDR*)&pPacket->DstIP));
					printf("Client:%s\n",inet_ntoa(*(IN_ADDR*)&pPacket->SrcIP));
				//	if(Base64Decode(databuffer,(int)strlen(databuffer),(BYTE *)Decode,&DecodeLen) == FALSE)
				//		continue;
				// printf("User Name:%s\t",Decode);
					bsmtpuser = TRUE;
				//	ZeroMemory(Decode,100);
				//	continue;
				}
				else if(bsmtppass == FALSE)
				{
				//	if(Base64Decode(databuffer,(int)strlen(databuffer),(BYTE *)Decode,&DecodeLen) == FALSE)
				//		continue;
				//	printf("Password:%s\n",Decode);
					bsmtppass = TRUE;
				//ZeroMemory(Decode,100);
					//continue;
				}
				if((bsmtppass == TRUE)&&(bsmtppass == TRUE))
				{
					Temp3=strstr(databuffer,"MAIL FROM");
					if(Temp3!=NULL)				              	
					{
						Temp3+=10;					
					    printf(TEXT("FROM:"));
						while(!((*Temp3=='\r')&&(*(Temp3+1)=='\n')))
						{
							putchar(*Temp3);
							Temp3++;
						}
						_tprintf(TEXT("\t"));
						Temp3 = NULL;
					}
					else
					{
						Temp3=strstr(databuffer,"RCPT TO");
						if(Temp3!=NULL)					
						{
							Temp3+=8;
							_tprintf(TEXT("TO:"));
							while(!((*Temp3=='\r')&&(*(Temp3+1)=='\n')))
							{
								putchar(*Temp3);
								Temp3++;
							}
							_tprintf(TEXT("\r\n"));
							Temp3 = NULL;
						}
					}
					
				}
			}
*/
}