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.util.Base64;
029
030
031 /**
032 * An SMTP Client class with authentication support (RFC4954).
033 *
034 * @see SMTPClient
035 * @since 3.0
036 */
037 public class AuthenticatingSMTPClient extends SMTPSClient
038 {
039 /**
040 * The default AuthenticatingSMTPClient constructor.
041 * Creates a new Authenticating SMTP Client.
042 * @throws NoSuchAlgorithmException
043 */
044 public AuthenticatingSMTPClient() throws NoSuchAlgorithmException
045 {
046 super();
047 }
048
049 /**
050 * Overloaded constructor that takes a protocol specification
051 * @param protocol The protocol to use
052 * @throws NoSuchAlgorithmException
053 */
054 public AuthenticatingSMTPClient(String protocol) throws NoSuchAlgorithmException {
055 super(protocol);
056 }
057
058 /***
059 * A convenience method to send the ESMTP EHLO command to the server,
060 * receive the reply, and return the reply code.
061 * <p>
062 * @param hostname The hostname of the sender.
063 * @return The reply code received from the server.
064 * @exception SMTPConnectionClosedException
065 * If the SMTP server prematurely closes the connection as a result
066 * of the client being idle or some other reason causing the server
067 * to send SMTP reply code 421. This exception may be caught either
068 * as an IOException or independently as itself.
069 * @exception IOException If an I/O error occurs while either sending the
070 * command or receiving the server reply.
071 ***/
072 public int ehlo(String hostname) throws IOException
073 {
074 return sendCommand(SMTPCommand.EHLO, hostname);
075 }
076
077 /***
078 * Login to the ESMTP server by sending the EHLO command with the
079 * given hostname as an argument. Before performing any mail commands,
080 * you must first login.
081 * <p>
082 * @param hostname The hostname with which to greet the SMTP server.
083 * @return True if successfully completed, false if not.
084 * @exception SMTPConnectionClosedException
085 * If the SMTP server prematurely closes the connection as a result
086 * of the client being idle or some other reason causing the server
087 * to send SMTP reply code 421. This exception may be caught either
088 * as an IOException or independently as itself.
089 * @exception IOException If an I/O error occurs while either sending a
090 * command to the server or receiving a reply from the server.
091 ***/
092 public boolean elogin(String hostname) throws IOException
093 {
094 return SMTPReply.isPositiveCompletion(ehlo(hostname));
095 }
096
097
098 /***
099 * Login to the ESMTP server by sending the EHLO command with the
100 * client hostname as an argument. Before performing any mail commands,
101 * you must first login.
102 * <p>
103 * @return True if successfully completed, false if not.
104 * @exception SMTPConnectionClosedException
105 * If the SMTP server prematurely closes the connection as a result
106 * of the client being idle or some other reason causing the server
107 * to send SMTP reply code 421. This exception may be caught either
108 * as an IOException or independently as itself.
109 * @exception IOException If an I/O error occurs while either sending a
110 * command to the server or receiving a reply from the server.
111 ***/
112 public boolean elogin() throws IOException
113 {
114 String name;
115 InetAddress host;
116
117 host = getLocalAddress();
118 name = host.getHostName();
119
120 if (name == null) {
121 return false;
122 }
123
124 return SMTPReply.isPositiveCompletion(ehlo(name));
125 }
126
127 /***
128 * Returns the integer values of the enhanced reply code of the last SMTP reply.
129 * @return The integer values of the enhanced reply code of the last SMTP reply.
130 * First digit is in the first array element.
131 ***/
132 public int[] getEnhancedReplyCode()
133 {
134 String reply = getReplyString().substring(4);
135 String[] parts = reply.substring(0, reply.indexOf(' ')).split ("\\.");
136 int[] res = new int[parts.length];
137 for (int i = 0; i < parts.length; i++)
138 {
139 res[i] = Integer.parseInt (parts[i]);
140 }
141 return res;
142 }
143
144 /***
145 * Authenticate to the SMTP server by sending the AUTH command with the
146 * selected mechanism, using the given username and the given password.
147 * <p>
148 * @return True if successfully completed, false if not.
149 * @exception SMTPConnectionClosedException
150 * If the SMTP server prematurely closes the connection as a result
151 * of the client being idle or some other reason causing the server
152 * to send SMTP reply code 421. This exception may be caught either
153 * as an IOException or independently as itself.
154 * @exception IOException If an I/O error occurs while either sending a
155 * command to the server or receiving a reply from the server.
156 * @exception NoSuchAlgorithmException If the CRAM hash algorithm
157 * cannot be instantiated by the Java runtime system.
158 * @exception InvalidKeyException If the CRAM hash algorithm
159 * failed to use the given password.
160 * @exception InvalidKeySpecException If the CRAM hash algorithm
161 * failed to use the given password.
162 ***/
163 public boolean auth(AuthenticatingSMTPClient.AUTH_METHOD method,
164 String username, String password)
165 throws IOException, NoSuchAlgorithmException,
166 InvalidKeyException, InvalidKeySpecException
167 {
168 if (!SMTPReply.isPositiveIntermediate(sendCommand(SMTPCommand.AUTH,
169 AUTH_METHOD.getAuthName(method)))) {
170 return false;
171 }
172
173 if (method.equals(AUTH_METHOD.PLAIN))
174 {
175 // the server sends an empty response ("334 "), so we don't have to read it.
176 return SMTPReply.isPositiveCompletion(sendCommand(
177 new String(
178 Base64.encodeBase64(("\000" + username + "\000" + password).getBytes())
179 )
180 ));
181 }
182 else if (method.equals(AUTH_METHOD.CRAM_MD5))
183 {
184 // get the CRAM challenge
185 byte[] serverChallenge = Base64.decodeBase64(getReplyString().substring(4).trim());
186 // get the Mac instance
187 Mac hmac_md5 = Mac.getInstance("HmacMD5");
188 hmac_md5.init(new SecretKeySpec(password.getBytes(), "HmacMD5"));
189 // compute the result:
190 byte[] hmacResult = _convertToHexString(hmac_md5.doFinal(serverChallenge)).getBytes();
191 // join the byte arrays to form the reply
192 byte[] usernameBytes = username.getBytes();
193 byte[] toEncode = new byte[usernameBytes.length + 1 /* the space */ + hmacResult.length];
194 System.arraycopy(usernameBytes, 0, toEncode, 0, usernameBytes.length);
195 toEncode[usernameBytes.length] = ' ';
196 System.arraycopy(hmacResult, 0, toEncode, usernameBytes.length + 1, hmacResult.length);
197 // send the reply and read the server code:
198 return SMTPReply.isPositiveCompletion(sendCommand(
199 new String(Base64.encodeBase64(toEncode))));
200 }
201 else if (method.equals(AUTH_METHOD.LOGIN))
202 {
203 // the server sends fixed responses (base64("Username") and
204 // base64("Password")), so we don't have to read them.
205 if (!SMTPReply.isPositiveIntermediate(sendCommand(
206 new String(Base64.encodeBase64(username.getBytes()))))) {
207 return false;
208 }
209 return SMTPReply.isPositiveCompletion(sendCommand(
210 new String(Base64.encodeBase64(password.getBytes()))));
211 } else {
212 return false; // safety check
213 }
214 }
215
216 /**
217 * Converts the given byte array to a String containing the hex values of the bytes.
218 * For example, the byte 'A' will be converted to '41', because this is the ASCII code
219 * (and the byte value) of the capital letter 'A'.
220 * @param a The byte array to convert.
221 * @return The resulting String of hex codes.
222 */
223 private String _convertToHexString(byte[] a)
224 {
225 StringBuilder result = new StringBuilder(a.length*2);
226 for (int i = 0; i < a.length; i++)
227 {
228 if ( (a[i] & 0x0FF) <= 15 ) {
229 result.append("0");
230 }
231 result.append(Integer.toHexString(a[i] & 0x0FF));
232 }
233 return result.toString();
234 }
235
236 /**
237 * The enumeration of currently-supported authentication methods.
238 */
239 public static enum AUTH_METHOD
240 {
241 /** The standarised (RFC4616) PLAIN method, which sends the password unencrypted (insecure). */
242 PLAIN,
243 /** The standarised (RFC2195) CRAM-MD5 method, which doesn't send the password (secure). */
244 CRAM_MD5,
245 /** The unstandarised Microsoft LOGIN method, which sends the password unencrypted (insecure). */
246 LOGIN;
247
248 /**
249 * Gets the name of the given authentication method suitable for the server.
250 * @param method The authentication method to get the name for.
251 * @return The name of the given authentication method suitable for the server.
252 */
253 public static final String getAuthName(AUTH_METHOD method)
254 {
255 if (method.equals(AUTH_METHOD.PLAIN)) {
256 return "PLAIN";
257 } else if (method.equals(AUTH_METHOD.CRAM_MD5)) {
258 return "CRAM-MD5";
259 } else if (method.equals(AUTH_METHOD.LOGIN)) {
260 return "LOGIN";
261 } else {
262 return null;
263 }
264 }
265 }
266 }
267
268 /* kate: indent-width 4; replace-tabs on; */