001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.net.smtp;
019
020 import java.io.IOException;
021 import java.net.InetAddress;
022 import java.security.InvalidKeyException;
023 import java.security.NoSuchAlgorithmException;
024 import java.security.spec.InvalidKeySpecException;
025 import javax.crypto.Mac;
026 import javax.crypto.spec.SecretKeySpec;
027
028 import org.apache.commons.net.smtp.SMTPClient;
029 import org.apache.commons.net.smtp.SMTPReply;
030 import org.apache.commons.net.util.Base64;
031
032
033 /**
034 * An SMTP Client class with authentication support (RFC4954).
035 *
036 * @see SMTPClient
037 * @since 3.0
038 */
039 public class AuthenticatingSMTPClient extends SMTPSClient
040 {
041 /**
042 * The default AuthenticatingSMTPClient constructor.
043 * Creates a new Authenticating SMTP Client.
044 * @throws NoSuchAlgorithmException
045 */
046 public AuthenticatingSMTPClient() throws NoSuchAlgorithmException
047 {
048 super();
049 }
050
051 /**
052 * Overloaded constructor that takes an encoding specification
053 * @param encoding The encoding to use
054 * @throws NoSuchAlgorithmException
055 */
056 public AuthenticatingSMTPClient(String encoding) throws NoSuchAlgorithmException {
057 super(encoding);
058 }
059
060 /***
061 * A convenience method to send the ESMTP EHLO command to the server,
062 * receive the reply, and return the reply code.
063 * <p>
064 * @param hostname The hostname of the sender.
065 * @return The reply code received from the server.
066 * @exception SMTPConnectionClosedException
067 * If the SMTP server prematurely closes the connection as a result
068 * of the client being idle or some other reason causing the server
069 * to send SMTP reply code 421. This exception may be caught either
070 * as an IOException or independently as itself.
071 * @exception IOException If an I/O error occurs while either sending the
072 * command or receiving the server reply.
073 ***/
074 public int ehlo(String hostname) throws IOException
075 {
076 return sendCommand(SMTPCommand.EHLO, hostname);
077 }
078
079 /***
080 * Login to the ESMTP server by sending the EHLO command with the
081 * given hostname as an argument. Before performing any mail commands,
082 * you must first login.
083 * <p>
084 * @param hostname The hostname with which to greet the SMTP server.
085 * @return True if successfully completed, false if not.
086 * @exception SMTPConnectionClosedException
087 * If the SMTP server prematurely closes the connection as a result
088 * of the client being idle or some other reason causing the server
089 * to send SMTP reply code 421. This exception may be caught either
090 * as an IOException or independently as itself.
091 * @exception IOException If an I/O error occurs while either sending a
092 * command to the server or receiving a reply from the server.
093 ***/
094 public boolean elogin(String hostname) throws IOException
095 {
096 return SMTPReply.isPositiveCompletion(ehlo(hostname));
097 }
098
099
100 /***
101 * Login to the ESMTP server by sending the EHLO command with the
102 * client hostname as an argument. Before performing any mail commands,
103 * you must first login.
104 * <p>
105 * @return True if successfully completed, false if not.
106 * @exception SMTPConnectionClosedException
107 * If the SMTP server prematurely closes the connection as a result
108 * of the client being idle or some other reason causing the server
109 * to send SMTP reply code 421. This exception may be caught either
110 * as an IOException or independently as itself.
111 * @exception IOException If an I/O error occurs while either sending a
112 * command to the server or receiving a reply from the server.
113 ***/
114 public boolean elogin() throws IOException
115 {
116 String name;
117 InetAddress host;
118
119 host = getLocalAddress();
120 name = host.getHostName();
121
122 if (name == null)
123 return false;
124
125 return SMTPReply.isPositiveCompletion(ehlo(name));
126 }
127
128 /***
129 * Returns the integer values of the enhanced reply code of the last SMTP reply.
130 * @return The integer values of the enhanced reply code of the last SMTP reply.
131 * First digit is in the first array element.
132 ***/
133 public int[] getEnhancedReplyCode()
134 {
135 String reply = getReplyString().substring(4);
136 String[] parts = reply.substring(0, reply.indexOf(' ')).split ("\\.");
137 int[] res = new int[parts.length];
138 for (int i = 0; i < parts.length; i++)
139 {
140 res[i] = Integer.parseInt (parts[i]);
141 }
142 return res;
143 }
144
145 /***
146 * Authenticate to the SMTP server by sending the AUTH command with the
147 * selected mechanism, using the given username and the given password.
148 * <p>
149 * @return True if successfully completed, false if not.
150 * @exception SMTPConnectionClosedException
151 * If the SMTP server prematurely closes the connection as a result
152 * of the client being idle or some other reason causing the server
153 * to send SMTP reply code 421. This exception may be caught either
154 * as an IOException or independently as itself.
155 * @exception IOException If an I/O error occurs while either sending a
156 * command to the server or receiving a reply from the server.
157 * @exception NoSuchAlgorithmException If the CRAM hash algorithm
158 * cannot be instantiated by the Java runtime system.
159 * @exception InvalidKeyException If the CRAM hash algorithm
160 * failed to use the given password.
161 * @exception InvalidKeySpecException If the CRAM hash algorithm
162 * failed to use the given password.
163 ***/
164 public boolean auth(AuthenticatingSMTPClient.AUTH_METHOD method,
165 String username, String password)
166 throws IOException, NoSuchAlgorithmException,
167 InvalidKeyException, InvalidKeySpecException
168 {
169 if (!SMTPReply.isPositiveIntermediate(sendCommand(SMTPCommand.AUTH,
170 AUTH_METHOD.getAuthName(method)))) return false;
171
172 if (method.equals(AUTH_METHOD.PLAIN))
173 {
174 // the server sends an empty response ("334 "), so we don't have to read it.
175 return SMTPReply.isPositiveCompletion(sendCommand(
176 new String(
177 Base64.encodeBase64(("\000" + username + "\000" + password).getBytes())
178 )
179 ));
180 }
181 else if (method.equals(AUTH_METHOD.CRAM_MD5))
182 {
183 // get the CRAM challenge
184 byte[] serverChallenge = Base64.decodeBase64(getReplyString().substring(4).trim());
185 // get the Mac instance
186 Mac hmac_md5 = Mac.getInstance("HmacMD5");
187 hmac_md5.init(new SecretKeySpec(password.getBytes(), "HmacMD5"));
188 // compute the result:
189 byte[] hmacResult = _convertToHexString(hmac_md5.doFinal(serverChallenge)).getBytes();
190 // join the byte arrays to form the reply
191 byte[] usernameBytes = username.getBytes();
192 byte[] toEncode = new byte[usernameBytes.length + 1 /* the space */ + hmacResult.length];
193 System.arraycopy(usernameBytes, 0, toEncode, 0, usernameBytes.length);
194 toEncode[usernameBytes.length] = ' ';
195 System.arraycopy(hmacResult, 0, toEncode, usernameBytes.length + 1, hmacResult.length);
196 // send the reply and read the server code:
197 return SMTPReply.isPositiveCompletion(sendCommand(
198 new String(Base64.encodeBase64(toEncode))));
199 }
200 else if (method.equals(AUTH_METHOD.LOGIN))
201 {
202 // the server sends fixed responses (base64("Username") and
203 // base64("Password")), so we don't have to read them.
204 if (!SMTPReply.isPositiveIntermediate(sendCommand(
205 new String(Base64.encodeBase64(username.getBytes()))))) return false;
206 return SMTPReply.isPositiveCompletion(sendCommand(
207 new String(Base64.encodeBase64(password.getBytes()))));
208 }
209 else return false; // safety check
210 }
211
212 /**
213 * Converts the given byte array to a String containing the hex values of the bytes.
214 * For example, the byte 'A' will be converted to '41', because this is the ASCII code
215 * (and the byte value) of the capital letter 'A'.
216 * @param a The byte array to convert.
217 * @return The resulting String of hex codes.
218 */
219 private String _convertToHexString(byte[] a)
220 {
221 StringBuilder result = new StringBuilder(a.length*2);
222 for (int i = 0; i < a.length; i++)
223 {
224 if ( (a[i] & 0x0FF) <= 15 ) result.append("0");
225 result.append(Integer.toHexString(a[i] & 0x0FF));
226 }
227 return result.toString();
228 }
229
230 /**
231 * The enumeration of currently-supported authentication methods.
232 */
233 public static enum AUTH_METHOD
234 {
235 /** The standarised (RFC4616) PLAIN method, which sends the password unencrypted (insecure). */
236 PLAIN,
237 /** The standarised (RFC2195) CRAM-MD5 method, which doesn't send the password (secure). */
238 CRAM_MD5,
239 /** The unstandarised Microsoft LOGIN method, which sends the password unencrypted (insecure). */
240 LOGIN;
241
242 /**
243 * Gets the name of the given authentication method suitable for the server.
244 * @param method The authentication method to get the name for.
245 * @return The name of the given authentication method suitable for the server.
246 */
247 public static final String getAuthName(AUTH_METHOD method)
248 {
249 if (method.equals(AUTH_METHOD.PLAIN)) return "PLAIN";
250 else if (method.equals(AUTH_METHOD.CRAM_MD5)) return "CRAM-MD5";
251 else if (method.equals(AUTH_METHOD.LOGIN)) return "LOGIN";
252 else return null;
253 }
254 }
255 }
256
257 /* kate: indent-width 4; replace-tabs on; */