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.OutputStreamWriter;
   7 import java.io.PrintWriter;
   8 import java.net.Socket;
   9 import java.security.GeneralSecurityException;
  10 import java.security.Key;
  11 import java.security.PrivateKey;
  12 import java.security.cert.Certificate;
  13 import java.security.cert.X509Certificate;
  14 import java.util.Arrays;
  15 import java.util.Comparator;
  16 import java.util.Properties;
  17 import java.util.regex.Pattern;
  18
  19 import javax.naming.NamingException;
  20 import javax.net.ssl.SSLSocketFactory;
  21
  22 import org.cacert.gigi.crypto.SMIME;
  23 import org.cacert.gigi.database.GigiPreparedStatement;
  24 import org.cacert.gigi.util.DNSUtil;
  25 import org.cacert.gigi.util.DomainAssessment;
  26
  27 public abstract class EmailProvider {
  28
  29     public abstract void sendMail(String to, String subject, String message, String replyto, String toname, String fromname, String errorsto, boolean extra) throws IOException;
  30
  31     private static EmailProvider instance;
  32
  33     private X509Certificate c;
  34
  35     private PrivateKey k;
  36
  37     protected void init(Certificate c, Key k) {
  38         this.c = (X509Certificate) c;
  39         this.k = (PrivateKey) k;
  40     }
  41
  42     protected final void sendSigned(String contents, PrintWriter output) throws IOException, GeneralSecurityException {
  43         if (k == null || c == null) {
  44             output.println("Content-Transfer-Encoding: base64");
  45             output.println();
  46             output.print(contents);
  47         } else {
  48             SMIME.smime(contents, k, c, output);
  49         }
  50     }
  51
  52     public static EmailProvider getInstance() {
  53         return instance;
  54     }
  55
  56     protected static void setInstance(EmailProvider instance) {
  57         EmailProvider.instance = instance;
  58     }
  59
  60     public static void initSystem(Properties conf, Certificate cert, Key pk) {
  61         try {
  62             Class<?> c = Class.forName(conf.getProperty("emailProvider"));
  63             EmailProvider ep = (EmailProvider) c.getDeclaredConstructor(Properties.class).newInstance(conf);
  64             ep.init(cert, pk);
  65             instance = ep;
  66         } catch (ReflectiveOperationException e) {
  67             e.printStackTrace();
  68         }
  69     }
  70
  71     public static final String OK = "OK";
  72
  73     public static final String FAIL = "FAIL";
  74
  75     private static final String MAIL_P_RFC_WORD = "[A-Za-z0-9\\+\\.!#$%&'*/=?^_`|~{}-]+";
  76
  77     private static final String MAIL_P_RFC_LOCAL = MAIL_P_RFC_WORD + "(?:\\." + MAIL_P_RFC_WORD + ")*";
  78
  79     private static final String MAIL_P_RFC_LABEL = "(?!(?!xn)..--|-)(?:[A-Za-z0-9-]+)(?<!-)";
  80
  81     private static final String MAIL_P_RFC_ADDRESS = MAIL_P_RFC_LOCAL + "@(?:" + MAIL_P_RFC_LABEL + "\\.)+" + MAIL_P_RFC_LABEL + "\\.?";
  82
  83     private static final Pattern MAIL_LOCAL = Pattern.compile("^" + MAIL_P_RFC_LOCAL + "$");
  84
  85     private static final Pattern MAIL_ADDRESS = Pattern.compile("^" + MAIL_P_RFC_ADDRESS + "$");
  86
  87     public String checkEmailServer(int forUid, String address) throws IOException {
  88         if (isValidMailAddress(address)) {
  89             String[] parts = address.split("@", 2);
  90             String domain = parts[1];
  91
  92             String[] mxhosts;
  93             try {
  94                 mxhosts = DNSUtil.getMXEntries(domain);
  95             } catch (NamingException e1) {
  96                 return "MX lookup for your hostname failed.";
  97             }
  98             sortMX(mxhosts);
  99
 100             for (String host : mxhosts) {
 101                 host = host.split(" ", 2)[1];
 102                 if (host.endsWith(".")) {
 103                     host = host.substring(0, host.length() - 1);
 104                 } else {
 105                     return "Strange MX records.";
 106                 }
 107                 try (Socket s = new Socket(host, 25);
 108                         BufferedReader br0 = new BufferedReader(new InputStreamReader(s.getInputStream(), "UTF-8"));//
 109                         PrintWriter pw0 = new PrintWriter(new OutputStreamWriter(s.getOutputStream(), "UTF-8"))) {
 110                     BufferedReader br = br0;
 111                     PrintWriter pw = pw0;
 112                     String line;
 113                     if ( !SendMail.readSMTPResponse(br, 220)) {
 114                         continue;
 115                     }
 116
 117                     pw.print("EHLO www.cacert.org\r\n");
 118                     pw.flush();
 119                     boolean starttls = false;
 120                     do {
 121                         line = br.readLine();
 122                         if (line == null) {
 123                             break;
 124                         }
 125                         starttls |= line.substring(4).equals("STARTTLS");
 126                     } while (line.startsWith("250-"));
 127                     if (line == null || !line.startsWith("250 ")) {
 128                         continue;
 129                     }
 130
 131                     if (starttls) {
 132                         pw.print("STARTTLS\r\n");
 133                         pw.flush();
 134                         if ( !SendMail.readSMTPResponse(br, 220)) {
 135                             continue;
 136                         }
 137                         Socket s1 = ((SSLSocketFactory) SSLSocketFactory.getDefault()).createSocket(s, host, 25, true);
 138                         br = new BufferedReader(new InputStreamReader(s1.getInputStream(), "UTF-8"));
 139                         pw = new PrintWriter(new OutputStreamWriter(s1.getOutputStream(), "UTF-8"));
 140                         pw.print("EHLO www.cacert.org\r\n");
 141                         pw.flush();
 142                         if ( !SendMail.readSMTPResponse(br, 250)) {
 143                             continue;
 144                         }
 145                     }
 146
 147                     pw.print("MAIL FROM: <returns@cacert.org>\r\n");
 148                     pw.flush();
 149
 150                     if ( !SendMail.readSMTPResponse(br, 250)) {
 151                         continue;
 152                     }
 153                     pw.print("RCPT TO: <" + address + ">\r\n");
 154                     pw.flush();
 155
 156                     if ( !SendMail.readSMTPResponse(br, 250)) {
 157                         continue;
 158                     }
 159                     pw.print("QUIT\r\n");
 160                     pw.flush();
 161                     if ( !SendMail.readSMTPResponse(br, 221)) {
 162                         continue;
 163                     }
 164
 165                     try (GigiPreparedStatement statmt = new GigiPreparedStatement("INSERT INTO `emailPinglog` SET `when`=NOW(), `email`=?, `result`=?, `uid`=?, `type`='fast', `status`=?::`pingState`")) {
 166                         statmt.setString(1, address);
 167                         statmt.setString(2, line);
 168                         statmt.setInt(3, forUid);
 169                         statmt.setString(4, "success");
 170                         statmt.execute();
 171                     }
 172
 173                     if (line == null || !line.startsWith("250")) {
 174                         return line;
 175                     } else {
 176                         return OK;
 177                     }
 178                 }
 179
 180             }
 181         }
 182         try (GigiPreparedStatement statmt = new GigiPreparedStatement("INSERT INTO `emailPinglog` SET `when`=NOW(), `email`=?, `result`=?, `uid`=?, `type`='fast', `status`=?::`pingState`")) {
 183             statmt.setString(1, address);
 184             statmt.setString(2, "Failed to make a connection to the mail server");
 185             statmt.setInt(3, forUid);
 186             statmt.setString(4, "failed");
 187             statmt.execute();
 188         }
 189         return FAIL;
 190     }
 191
 192     private static void sortMX(String[] mxhosts) {
 193         Arrays.sort(mxhosts, new Comparator<String>() {
 194
 195             @Override
 196             public int compare(String o1, String o2) {
 197                 int i1 = Integer.parseInt(o1.split(" ")[0]);
 198                 int i2 = Integer.parseInt(o2.split(" ")[0]);
 199                 return Integer.compare(i1, i2);
 200             }
 201         });
 202     }
 203
 204     public static boolean isValidMailAddress(String address) {
 205         if ( !MAIL_ADDRESS.matcher(address).matches()) {
 206             return false;
 207         }
 208
 209         String[] parts = address.split("@", 2);
 210
 211         String local = parts[0];
 212         String domain = parts[1];
 213
 214         if ( !MAIL_LOCAL.matcher(local).matches()) {
 215             return false;
 216         }
 217
 218         for (String domainPart : domain.split("\\.", -1)) {
 219             if ( !DomainAssessment.isValidDomainPart(domainPart)) {
 220                 return false;
 221             }
 222         }
 223
 224         return true;
 225     }
 226
 227 }