+package org.cacert.gigi.util;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.Socket;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.util.LinkedList;
+import java.util.regex.Pattern;
+
+import org.cacert.gigi.database.DatabaseConnection;
+
+public class EmailChecker {
+ public static final String OK = "OK";
+ public static final String FAIL = "FAIL";
+ private static final Pattern MAIL = Pattern
+ .compile("^([a-zA-Z0-9])+([a-zA-Z0-9\\+\\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\\._-]+)+$");
+ private EmailChecker() {
+ }
+ public static String checkEmailServer(int forUid, String address)
+ throws IOException {
+ if (MAIL.matcher(address).matches()) {
+ String[] parts = address.split("@", 2);
+ String domain = parts[1];
+
+ LinkedList<String> mxhosts = getMxHosts(domain);
+
+ for (String host : mxhosts) {
+ try (Socket s = new Socket(host, 25);
+ BufferedReader br = new BufferedReader(
+ new InputStreamReader(s.getInputStream()));
+ PrintWriter pw = new PrintWriter(s.getOutputStream())) {
+ String line;
+ while ((line = br.readLine()).startsWith("220-")) {
+ }
+
+ if (!line.startsWith("220")) {
+ continue;
+ }
+
+ pw.print("HELO www.cacert.org\r\n");
+ pw.flush();
+
+ while ((line = br.readLine()).startsWith("220")) {
+ }
+
+ if (!line.startsWith("250")) {
+ continue;
+ }
+ pw.print("MAIL FROM: <returns@cacert.org>\r\n");
+ pw.flush();
+
+ line = br.readLine();
+
+ if (!line.startsWith("250")) {
+ continue;
+ }
+ pw.print("RCPT TO: <" + address + ">\r\n");
+ pw.flush();
+
+ line = br.readLine();
+ pw.print("QUIT\r\n");
+ pw.flush();
+
+ try {
+ PreparedStatement statmt = DatabaseConnection
+ .getInstance()
+ .prepare(
+ "insert into `pinglog` set `when`=NOW(), `email`=?, `result`=?, `uid`=?");
+ statmt.setString(1, address);
+ statmt.setString(2, line);
+ statmt.setInt(3, forUid);
+ statmt.execute();
+ } catch (SQLException e) {
+ e.printStackTrace();
+ }
+
+ if (!line.startsWith("250")) {
+ return line;
+ } else {
+ return OK;
+ }
+ }
+
+ }
+ }
+ try {
+ PreparedStatement statmt = DatabaseConnection
+ .getInstance()
+ .prepare(
+ "insert into `pinglog` set `when`=NOW(), `email`=?, `result`=?, `uid`=?");
+ statmt.setString(1, address);
+ statmt.setString(2,
+ "Failed to make a connection to the mail server");
+ statmt.setInt(3, forUid);
+ statmt.execute();
+ } catch (SQLException e) {
+ e.printStackTrace();
+ }
+ return FAIL;
+ }
+ private static LinkedList<String> getMxHosts(String domain)
+ throws IOException {
+ LinkedList<String> mxhosts = new LinkedList<String>();
+ Process dig = Runtime.getRuntime().exec(
+ new String[]{"dig", "+short", "MX", domain});
+ try (BufferedReader br = new BufferedReader(new InputStreamReader(
+ dig.getInputStream()))) {
+ String line;
+ while ((line = br.readLine()) != null) {
+ String[] mxparts = line.split(" ", 2);
+ if (mxparts.length != 2) {
+ continue;
+ }
+ mxhosts.add(mxparts[1].substring(0, mxparts[1].length() - 1));
+ }
+ }
+ return mxhosts;
+ }
+
+}