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smtp.c
146 lines (128 loc) · 3.63 KB
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smtp.c
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#include "smtp.h"
#include "base64.h"
int print_help(void){
printf("How to use it:\n");
printf(" smtp host [port]\n");
printf(" the default port is 25\n");
return 0;
}
int connect2server(int *socket_p,char *host,char *port){
char response[BUFSIZ] = "";
struct addrinfo hint = {0},*res = NULL;
int function_flag = -1;
hint.ai_family = AF_UNSPEC;
hint.ai_socktype = SOCK_STREAM;
function_flag = getaddrinfo(host,"smtp",&hint,&res);
if (function_flag != 0){
return -1;
}else{
struct addrinfo *temp = res;
while (temp){
*socket_p = socket(temp->ai_family,SOCK_STREAM,temp->ai_protocol);
if (*socket_p == -1){
temp = temp->ai_next;
}else{
break;
}
}
function_flag = connect(*socket_p,temp->ai_addr,temp->ai_addrlen);
get_response(*socket_p,response,BUFSIZ);
printf("%s\n",response);
freeaddrinfo(res);
return function_flag;
}
}
int hello(int socket,char *hostname){
char message[108] = "HELO ";
strcat(message,hostname);
client_send(socket,message);
get_response(socket,message,108);
printf("%s",message);
return 0;
}
int authenticate(int socket,char *username,char *password){
char username_encode[512] = "";
char password_encode[512] = "";
char response[BUFSIZ] = "";
base64_encode(username,username_encode);
base64_encode(password,password_encode);
client_send(socket,"AUTH LOGIN");
get_response(socket,response,BUFSIZ);
client_send(socket,username_encode);
get_response(socket,response,BUFSIZ);
printf("%s\n",response);
if (response[0] == '4'||
response[0] == '5'){
perror("Account Deny!");
return -1;
}
client_send(socket,password_encode);
get_response(socket,response,BUFSIZ);
printf("%s",response);
if (response[0] == '4'||
response[0] == '5'){
perror("Password Wrong!");
return -1;
}
return 0;
}
int send_email(int socket,char *from,char *address,char *subject,char *content){
char message[BUFSIZ] = "";
char *content_encode = NULL;
strcpy(message,"MAIL FROM: <");
strcat(message,from);
strcat(message,">");
client_send(socket,message);
get_response(socket,message,BUFSIZ);
printf("%s\n",message);
strcpy(message,"RCPT TO: <");
strcat(message,address);
strcat(message,">");
client_send(socket,message);
get_response(socket,message,BUFSIZ);
printf("%s\n",message);
client_send(socket,"DATA");
get_response(socket,message,BUFSIZ);
printf("%s\n",message);
strcpy(message,"From: ");
strcat(message,from);
client_send(socket,message);
strcpy(message,"To: ");
strcat(message,address);
client_send(socket,message);
strcpy(message,"Subject:");
strcat(message,subject);
client_send(socket,message);
client_send(socket,"MIME-Version:1.0");
client_send(socket,"Content-Type:multipart/alternative;");
client_send(socket,"boundary=----=smtp_demo");
client_send(socket,"\r\n----=smtp_demo");
client_send(socket,"Content-Type:text/plain;charset=utf-8");
client_send(socket,"Content-Transfer-Encoding: 8bit\r\n");
client_send(socket,content);
client_send(socket,"\r\n----=smtp_demo");
client_send(socket,"Content-Type:text/html;charset=utf-8");
client_send(socket,"Content-Transfer-Encoding: 8bit\r\n");
client_send(socket,content);
client_send(socket,"\r\n----=smtp_demo");
client_send(socket,".");
memset(message,0,BUFSIZ);
get_response(socket,message,BUFSIZ);
printf("%s\n",message);
}
int client_send(int socket,char *message){
char buff[512] = {'\0'};
strcpy(buff,message);
strcat(buff,"\r\n");
printf("%s",buff);
return write(socket,buff,strlen(buff));
}
int get_response(int socket,char *response,int response_length){
int read_size = read(socket,response,response_length);
if (read_size == -1){
return -1;
}else{
response[read_size] = '\0';
return 0;
}
}