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仿照，SMTP协议初探（一）--我的前一篇博客，结合网上的材料，利用socket，写了个Linux下c编程实现的发邮件程序。
大家可以拿自己的邮箱去做实验啦，base64是一种编码方式，网上可以找到一个网页，可以查询密码的base64编码是多少。当然也可以自己手工计算（我没试过）。
具体源码如下：
//#include<iostream>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
//using namespace std;
#define EHLO "EHLO ***\r\n" //***为邮箱用户名
#define DATA "data\r\n"
#define QUIT "QUIT\r\n"
//#define h_addr h_addr_list[0]
//FILE *fin;
int sock;
struct sockaddr_in server;
struct hostent *hp, *gethostbyname();
char buf[BUFSIZ+1];
int len;
char *host_id="smtp.126.com";
char *from_id="***@126.com";
char *to_id="60462****@qq.com";
char *sub="testmail\r\n";
char wkstr[100]="hello how r u\r\n";
/*=====Send a string to the socket=====*/
void send_socket(char *s)
{
write(sock,s,strlen(s));
//write(1,s,strlen(s));
//printf("Client:%s\n",s);
}
//=====Read a string from the socket=====*/
void read_socket()
{
len = read(sock,buf,BUFSIZ);
write(1,buf,len);
//printf("Server:%s\n",buf);
}
/*=====MAIN=====*/
int main(int argc, char* argv[])
{
/*=====Create Socket=====*/
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock==-1)
{
perror("opening stream socket");
//exit(1);
return 1;
}
else
//cout << "socket created\n";
printf("socket created\n");
/*=====Verify host=====*/
server.sin_family = AF_INET;
hp = gethostbyname(host_id);
if (hp==(struct hostent *) 0)
{
fprintf(stderr, "%s: unknown host\n", host_id);
//exit(2);
return 2;
}
/*=====Connect to port 25 on remote host=====*/
memcpy((char *) &server.sin_addr, (char *) hp->h_addr, hp->h_length);
server.sin_port=htons(25); /* SMTP PORT */
if (connect(sock, (struct sockaddr *) &server, sizeof server)==-1)
{
perror("connecting stream socket");
//exit(1);
return 1;
}
else
//cout << "Connected\n";
printf("Connected\n");
/*=====Write some data then read some =====*/
read_socket(); /* SMTP Server logon string */
send_socket(EHLO); /* introduce ourselves */
read_socket(); /*Read reply */
/*
**added by fupeng
*/
send_socket("AUTH LOGIN");
send_socket("\r\n");
read_socket();
send_socket("*******");//用户名的base64编码
send_socket("\r\n");
read_socket();
send_socket("******");//密码的base64编码
send_socket("\r\n");
read_socket();
send_socket("mail from <");
send_socket(from_id);
send_socket(">");
send_socket("\r\n");
read_socket(); /* Sender OK */
//send_socket("VRFY ");
//send_socket(from_id);
//send_socket("\r\n");
//read_socket(); // Sender OK */
send_socket("rcpt to <"); /*Mail to*/
send_socket(to_id);
send_socket(">");
send_socket("\r\n");
read_socket(); // Recipient OK*/
send_socket(DATA);// body to follow*/
read_socket();
//send_socket("from:***@126.com");
send_socket("subject:");
send_socket(sub);
//read_socket(); // Recipient OK*/
send_socket("\r\n\r\n");
send_socket(wkstr);
send_socket(".\r\n");
read_socket();
send_socket(QUIT); /* quit */
read_socket(); // log off */
//=====Close socket and finish=====*/
close(sock);
//exit(0);
return 0;
}
具体结果如下图片所示：
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