C語言實現簡單的SMTP發送郵件
#include <windows.h>
#include <stdio.h>
#include <WinSock.h>
#include <iostream>
using namespace std;
#pragma comment(lib, "ws2_32.lib")
struct Base64Date6
{
unsigned int d4:6;
unsigned int d3:6;
unsigned int d2:6;
unsigned int d1:6;
};
// 協議中加密部分使用的是base64方法
char ConvertToBase64 (char c6);
void EncodeBase64 (char *dbuf, char *buf128, int len);
void SendMail (char *email,char *body);
int OpenSocket (struct sockaddr *addr);
int main()
{
char EmailTo[] = "hanyinlong@126.com";
char EmailContents[] = "From: \"lucy\"<hanyinlong@126.com>\r\n"
"To: \"dasiy\"<hanyinlong@126.com>\r\n"
"Subject: Hello\r\n\r\n"
"Hello World, Hello Email!";
SendMail(EmailTo, EmailContents);
return 0;
}
char ConvertToBase64(char uc)
{
if(uc < 26)
{
return 'A' + uc;
}
if(uc < 52)
{
return 'a' + (uc - 26);
}
if(uc < 62)
{
return '0' + (uc - 52);
}
if(uc == 62)
{
return '+';
}
return '/';
}
// base64的實現
void EncodeBase64(char *dbuf, char *buf128, int len)
{
struct Base64Date6 *ddd = NULL;
int i = 0;
char buf[256] = {0};
char *tmp = NULL;
char cc = '\0';
memset(buf, 0, 256);
strcpy_s(buf, 256, buf128);
for(i = 1; i <= len/3; i++)
{
tmp = buf + (i-1)*3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i-1)*4+2] = ConvertToBase64((unsigned int)ddd->d3);
dbuf[(i-1)*4+3] = ConvertToBase64((unsigned int)ddd->d4);
}
if(len % 3 == 1)
{
tmp = buf + (i-1)*3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i-1)*4+2] = '=';
dbuf[(i-1)*4+3] = '=';
}
if(len%3 == 2)
{
tmp = buf+(i-1)*3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i-1)*4+2] = ConvertToBase64((unsigned int)ddd->d3);
dbuf[(i-1)*4+3] = '=';
}
return;
}
// 發送郵件
void SendMail(char *email, char *body)
{
int sockfd = {0};
char buf[1500] = {0};
char rbuf[1500] = {0};
char login[128] = {0};
char pass[128] = {0};
WSADATA WSAData;
struct sockaddr_in their_addr = {0};
WSAStartup(MAKEWORD(2, 2), &WSAData);
memset(&their_addr, 0, sizeof(their_addr));
their_addr.sin_family = AF_INET;
their_addr.sin_port = htons(25);
hostent* hptr = gethostbyname("smtp.126.com");
memcpy(&their_addr.sin_addr.S_un.S_addr, hptr->h_addr_list[0], hptr->h_length);
printf("IP of smpt.126.com is : %d:%d:%d:%d\n",
their_addr.sin_addr.S_un.S_un_b.s_b1,
their_addr.sin_addr.S_un.S_un_b.s_b2,
their_addr.sin_addr.S_un.S_un_b.s_b3,
their_addr.sin_addr.S_un.S_un_b.s_b4);
// 連接郵件服務器，如果連接後沒有響應，則2 秒後重新連接
sockfd = OpenSocket((struct sockaddr *)&their_addr);
memset(rbuf, 0, 1500);
while(recv(sockfd, rbuf, 1500, 0) == 0)
{
cout<<"reconnect..."<<endl;
Sleep(2);
sockfd = OpenSocket((struct sockaddr *)&their_addr);
memset(rbuf, 0, 1500);
}
cout<<rbuf<<endl;
// EHLO
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "EHLO HYL-PC\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"EHLO REceive: "<<rbuf<<endl;
// AUTH LOGIN
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "AUTH LOGIN\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Auth Login Receive: "<<rbuf<<endl;
// USER
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "hanyinlong@126.com");//妳的郵箱賬號
memset(login, 0, 128);
EncodeBase64(login, buf, strlen(buf));
sprintf_s(buf, 1500, "%s\r\n", login);
send(sockfd, buf, strlen(buf), 0);
cout<<"Base64 UserName: "<<buf<<endl;
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"User Login Receive: "<<rbuf<<endl;
// PASSWORD
sprintf_s(buf, 1500, "XXXXXXXXXXXX");//妳的郵箱密碼
memset(pass, 0, 128);
EncodeBase64(pass, buf, strlen(buf));
sprintf_s(buf, 1500, "%s\r\n", pass);
send(sockfd, buf, strlen(buf), 0);
cout<<"Base64 Password: "<<buf<<endl;
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Send Password Receive: "<<rbuf<<endl;
// MAIL FROM
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "MAIL FROM: <hanyinlong@126.com>\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"set Mail From Receive: "<<rbuf<<endl;
// RCPT TO 第壹個收件人
sprintf_s(buf, 1500, "RCPT TO:<%s>\r\n", email);
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Tell Sendto Receive: "<<rbuf<<endl;
// DATA 準備開始發送郵件內容
sprintf_s(buf, 1500, "DATA\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Send Mail Prepare Receive: "<<rbuf<<endl;
// 發送郵件內容，\r\n.\r\n內容結束標記
sprintf_s(buf, 1500, "%s\r\n.\r\n", body);
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Send Mail Receive: "<<rbuf<<endl;
// QUIT
sprintf_s(buf, 1500, "QUIT\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Quit Receive: "<<rbuf<<endl;
//清理工作
closesocket(sockfd);
WSACleanup();
return;
}
// 打開TCP Socket連接
int OpenSocket(struct sockaddr *addr)
{
int sockfd = 0;
sockfd=socket(PF_INET, SOCK_STREAM, 0);
if(sockfd < 0)
{
cout<<"Open sockfd(TCP) error!"<<endl;
exit(-1);
}
if(connect(sockfd, addr, sizeof(struct sockaddr)) < 0)
{
cout<<"Connect sockfd(TCP) error!"<<endl;
exit(-1);
}
return sockfd;
}