src/org/cacert/gigi/util/EmailChecker.java

   1 package org.cacert.gigi.util;
   2
   3 import java.io.BufferedReader;
   4 import java.io.IOException;
   5 import java.io.InputStreamReader;
   6 import java.io.PrintWriter;
   7 import java.net.Socket;
   8 import java.sql.PreparedStatement;
   9 import java.sql.SQLException;
  10 import java.util.LinkedList;
  11 import java.util.regex.Pattern;
  12
  13 import org.cacert.gigi.database.DatabaseConnection;
  14
  15 public class EmailChecker {
  16         public static final String OK = "OK";
  17         public static final String FAIL = "FAIL";
  18         private static final Pattern MAIL = Pattern
  19                         .compile("^([a-zA-Z0-9])+([a-zA-Z0-9\\+\\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\\._-]+)+$");
  20         private EmailChecker() {
  21         }
  22         public static String checkEmailServer(int forUid, String address)
  23                         throws IOException {
  24                 if (MAIL.matcher(address).matches()) {
  25                         String[] parts = address.split("@", 2);
  26                         String domain = parts[1];
  27
  28                         LinkedList<String> mxhosts = getMxHosts(domain);
  29
  30                         for (String host : mxhosts) {
  31                                 try (Socket s = new Socket(host, 25);
  32                                                 BufferedReader br = new BufferedReader(
  33                                                                 new InputStreamReader(s.getInputStream()));
  34                                                 PrintWriter pw = new PrintWriter(s.getOutputStream())) {
  35                                         String line;
  36                                         while ((line = br.readLine()) != null
  37                                                         && line.startsWith("220-")) {
  38                                         }
  39                                         if (line == null || !line.startsWith("220")) {
  40                                                 continue;
  41                                         }
  42
  43                                         pw.print("HELO www.cacert.org\r\n");
  44                                         pw.flush();
  45
  46                                         while ((line = br.readLine()) != null
  47                                                         && line.startsWith("220")) {
  48                                         }
  49
  50                                         if (line == null || !line.startsWith("250")) {
  51                                                 continue;
  52                                         }
  53                                         pw.print("MAIL FROM: <returns@cacert.org>\r\n");
  54                                         pw.flush();
  55
  56                                         line = br.readLine();
  57
  58                                         if (line == null || !line.startsWith("250")) {
  59                                                 continue;
  60                                         }
  61                                         pw.print("RCPT TO: <" + address + ">\r\n");
  62                                         pw.flush();
  63
  64                                         line = br.readLine();
  65                                         pw.print("QUIT\r\n");
  66                                         pw.flush();
  67
  68                                         try {
  69                                                 PreparedStatement statmt = DatabaseConnection
  70                                                                 .getInstance()
  71                                                                 .prepare(
  72                                                                                 "insert into `pinglog` set `when`=NOW(), `email`=?, `result`=?, `uid`=?");
  73                                                 statmt.setString(1, address);
  74                                                 statmt.setString(2, line);
  75                                                 statmt.setInt(3, forUid);
  76                                                 statmt.execute();
  77                                         } catch (SQLException e) {
  78                                                 e.printStackTrace();
  79                                         }
  80
  81                                         if (line == null || !line.startsWith("250")) {
  82                                                 return line;
  83                                         } else {
  84                                                 return OK;
  85                                         }
  86                                 }
  87
  88                         }
  89                 }
  90                 try {
  91                         PreparedStatement statmt = DatabaseConnection
  92                                         .getInstance()
  93                                         .prepare(
  94                                                         "insert into `pinglog` set `when`=NOW(), `email`=?, `result`=?, `uid`=?");
  95                         statmt.setString(1, address);
  96                         statmt.setString(2,
  97                                         "Failed to make a connection to the mail server");
  98                         statmt.setInt(3, forUid);
  99                         statmt.execute();
 100                 } catch (SQLException e) {
 101                         e.printStackTrace();
 102                 }
 103                 return FAIL;
 104         }
 105         private static LinkedList<String> getMxHosts(String domain)
 106                         throws IOException {
 107                 LinkedList<String> mxhosts = new LinkedList<String>();
 108                 Process dig = Runtime.getRuntime().exec(
 109                                 new String[]{"dig", "+short", "MX", domain});
 110                 try (BufferedReader br = new BufferedReader(new InputStreamReader(
 111                                 dig.getInputStream()))) {
 112                         String line;
 113                         while ((line = br.readLine()) != null) {
 114                                 String[] mxparts = line.split(" ", 2);
 115                                 if (mxparts.length != 2) {
 116                                         continue;
 117                                 }
 118                                 mxhosts.add(mxparts[1].substring(0, mxparts[1].length() - 1));
 119                         }
 120                 }
 121                 return mxhosts;
 122         }
 123
 124 }