1 /* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
2 *
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 package org.springframework.security.providers.encoding;
17
18 /**
19 * <p>Convenience base for all password encoders.</p>
20 *
21 * @author Ben Alex
22 * @version $Id: BasePasswordEncoder.java 2217 2007-10-27 00:45:30Z luke_t $
23 */
24 public abstract class BasePasswordEncoder implements PasswordEncoder {
25 //~ Methods ========================================================================================================
26
27 /**
28 * Used by subclasses to extract the password and salt from a merged <code>String</code> created using
29 * {@link #mergePasswordAndSalt(String,Object,boolean)}.<p>The first element in the returned array is the
30 * password. The second element is the salt. The salt array element will always be present, even if no salt was
31 * found in the <code>mergedPasswordSalt</code> argument.</p>
32 *
33 * @param mergedPasswordSalt as generated by <code>mergePasswordAndSalt</code>
34 *
35 * @return an array, in which the first element is the password and the second the salt
36 *
37 * @throws IllegalArgumentException if mergedPasswordSalt is null or empty.
38 */
39 protected String[] demergePasswordAndSalt(String mergedPasswordSalt) {
40 if ((mergedPasswordSalt == null) || "".equals(mergedPasswordSalt)) {
41 throw new IllegalArgumentException("Cannot pass a null or empty String");
42 }
43
44 String password = mergedPasswordSalt;
45 String salt = "";
46
47 int saltBegins = mergedPasswordSalt.lastIndexOf("{");
48
49 if ((saltBegins != -1) && ((saltBegins + 1) < mergedPasswordSalt.length())) {
50 salt = mergedPasswordSalt.substring(saltBegins + 1, mergedPasswordSalt.length() - 1);
51 password = mergedPasswordSalt.substring(0, saltBegins);
52 }
53
54 return new String[] {password, salt};
55 }
56
57 /**
58 * Used by subclasses to generate a merged password and salt <code>String</code>.<P>The generated password
59 * will be in the form of <code>password{salt}</code>.</p>
60 * <p>A <code>null</code> can be passed to either method, and will be handled correctly. If the
61 * <code>salt</code> is <code>null</code> or empty, the resulting generated password will simply be the passed
62 * <code>password</code>. The <code>toString</code> method of the <code>salt</code> will be used to represent the
63 * salt.</p>
64 *
65 * @param password the password to be used (can be <code>null</code>)
66 * @param salt the salt to be used (can be <code>null</code>)
67 * @param strict ensures salt doesn't contain the delimiters
68 *
69 * @return a merged password and salt <code>String</code>
70 *
71 * @throws IllegalArgumentException if the salt contains '{' or '}' characters.
72 */
73 protected String mergePasswordAndSalt(String password, Object salt, boolean strict) {
74 if (password == null) {
75 password = "";
76 }
77
78 if (strict && (salt != null)) {
79 if ((salt.toString().lastIndexOf("{") != -1) || (salt.toString().lastIndexOf("}") != -1)) {
80 throw new IllegalArgumentException("Cannot use { or } in salt.toString()");
81 }
82 }
83
84 if ((salt == null) || "".equals(salt)) {
85 return password;
86 } else {
87 return password + "{" + salt.toString() + "}";
88 }
89 }
90 }