src/org/cacert/gigi/email/EmailProvider.java

   1 package org.cacert.gigi.email;
   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.security.GeneralSecurityException;
   9 import java.security.Key;
  10 import java.security.PrivateKey;
  11 import java.security.cert.Certificate;
  12 import java.security.cert.X509Certificate;
  13 import java.sql.PreparedStatement;
  14 import java.sql.SQLException;
  15 import java.util.LinkedList;
  16 import java.util.Properties;
  17 import java.util.regex.Pattern;
  18
  19 import org.cacert.gigi.crypto.SMIME;
  20 import org.cacert.gigi.database.DatabaseConnection;
  21
  22 public abstract class EmailProvider {
  23
  24     public abstract void sendmail(String to, String subject, String message, String from, String replyto, String toname, String fromname, String errorsto, boolean extra) throws IOException;
  25
  26     private static EmailProvider instance;
  27
  28     private X509Certificate c;
  29
  30     private PrivateKey k;
  31
  32     protected final void init(Certificate c, Key k) {
  33         this.c = (X509Certificate) c;
  34         this.k = (PrivateKey) k;
  35     }
  36
  37     protected final void sendSigned(String contents, PrintWriter output) throws IOException, GeneralSecurityException {
  38         SMIME.smime(contents, k, c, output);
  39     }
  40
  41     public static EmailProvider getInstance() {
  42         return instance;
  43     }
  44
  45     protected static void setInstance(EmailProvider instance) {
  46         EmailProvider.instance = instance;
  47     }
  48
  49     public static void initSystem(Properties conf, Certificate cert, Key pk) {
  50         try {
  51             Class<?> c = Class.forName(conf.getProperty("emailProvider"));
  52             EmailProvider ep = (EmailProvider) c.getDeclaredConstructor(Properties.class).newInstance(conf);
  53             ep.init(cert, pk);
  54             instance = ep;
  55         } catch (ReflectiveOperationException e) {
  56             e.printStackTrace();
  57         }
  58     }
  59
  60     public static final String OK = "OK";
  61
  62     public static final String FAIL = "FAIL";
  63
  64     public static final Pattern MAIL = Pattern.compile("^([a-zA-Z0-9])+([a-zA-Z0-9\\+\\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\\._-]+)+$");
  65
  66     public String checkEmailServer(int forUid, String address) throws IOException {
  67         if (MAIL.matcher(address).matches()) {
  68             String[] parts = address.split("@", 2);
  69             String domain = parts[1];
  70
  71             LinkedList<String> mxhosts = getMxHosts(domain);
  72
  73             for (String host : mxhosts) {
  74                 try (Socket s = new Socket(host, 25); BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream())); PrintWriter pw = new PrintWriter(s.getOutputStream())) {
  75                     String line;
  76                     while ((line = br.readLine()) != null && line.startsWith("220-")) {
  77                     }
  78                     if (line == null || !line.startsWith("220")) {
  79                         continue;
  80                     }
  81
  82                     pw.print("HELO www.cacert.org\r\n");
  83                     pw.flush();
  84
  85                     while ((line = br.readLine()) != null && line.startsWith("220")) {
  86                     }
  87
  88                     if (line == null || !line.startsWith("250")) {
  89                         continue;
  90                     }
  91                     pw.print("MAIL FROM: <returns@cacert.org>\r\n");
  92                     pw.flush();
  93
  94                     line = br.readLine();
  95
  96                     if (line == null || !line.startsWith("250")) {
  97                         continue;
  98                     }
  99                     pw.print("RCPT TO: <" + address + ">\r\n");
 100                     pw.flush();
 101
 102                     line = br.readLine();
 103                     pw.print("QUIT\r\n");
 104                     pw.flush();
 105
 106                     try {
 107                         PreparedStatement statmt = DatabaseConnection.getInstance().prepare("insert into `pinglog` set `when`=NOW(), `email`=?, `result`=?, `uid`=?");
 108                         statmt.setString(1, address);
 109                         statmt.setString(2, line);
 110                         statmt.setInt(3, forUid);
 111                         statmt.execute();
 112                     } catch (SQLException e) {
 113                         e.printStackTrace();
 114                     }
 115
 116                     if (line == null || !line.startsWith("250")) {
 117                         return line;
 118                     } else {
 119                         return OK;
 120                     }
 121                 }
 122
 123             }
 124         }
 125         try {
 126             PreparedStatement statmt = DatabaseConnection.getInstance().prepare("insert into `pinglog` set `when`=NOW(), `email`=?, `result`=?, `uid`=?");
 127             statmt.setString(1, address);
 128             statmt.setString(2, "Failed to make a connection to the mail server");
 129             statmt.setInt(3, forUid);
 130             statmt.execute();
 131         } catch (SQLException e) {
 132             e.printStackTrace();
 133         }
 134         return FAIL;
 135     }
 136
 137     private static LinkedList<String> getMxHosts(String domain) throws IOException {
 138         LinkedList<String> mxhosts = new LinkedList<String>();
 139         Process dig = Runtime.getRuntime().exec(new String[] {
 140                 "dig", "+short", "MX", domain
 141         });
 142         try (BufferedReader br = new BufferedReader(new InputStreamReader(dig.getInputStream()))) {
 143             String line;
 144             while ((line = br.readLine()) != null) {
 145                 String[] mxparts = line.split(" ", 2);
 146                 if (mxparts.length != 2) {
 147                     continue;
 148                 }
 149                 mxhosts.add(mxparts[1].substring(0, mxparts[1].length() - 1));
 150             }
 151         }
 152         return mxhosts;
 153     }
 154 }