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 import org.springframework.dao.DataAccessException; 19 20 21 /** 22 * <p> 23 * Interface for performing authentication operations on a password. 24 * </p> 25 * 26 * @author colin sampaleanu 27 * @version $Id: PasswordEncoder.java 2217 2007-10-27 00:45:30Z luke_t $ 28 */ 29 public interface PasswordEncoder { 30 //~ Methods ======================================================================================================== 31 32 /** 33 * <p>Encodes the specified raw password with an implementation specific algorithm.</p> 34 * <P>This will generally be a one-way message digest such as MD5 or SHA, but may also be a plaintext 35 * variant which does no encoding at all, but rather returns the same password it was fed. The latter is useful to 36 * plug in when the original password must be stored as-is.</p> 37 * <p>The specified salt will potentially be used by the implementation to "salt" the initial value before 38 * encoding. A salt is usually a user-specific value which is added to the password before the digest is computed. 39 * This means that computation of digests for common dictionary words will be different than those in the backend 40 * store, because the dictionary word digests will not reflect the addition of the salt. If a per-user salt is 41 * used (rather than a system-wide salt), it also means users with the same password will have different digest 42 * encoded passwords in the backend store.</p> 43 * <P>If a salt value is provided, the same salt value must be use when calling the {@link 44 * #isPasswordValid(String, String, Object)} method. Note that a specific implementation may choose to ignore the 45 * salt value (via <code>null</code>), or provide its own.</p> 46 * 47 * @param rawPass the password to encode 48 * @param salt optionally used by the implementation to "salt" the raw password before encoding. A 49 * <code>null</code> value is legal. 50 * 51 * @return encoded password 52 * 53 * @throws DataAccessException DOCUMENT ME! 54 */ 55 String encodePassword(String rawPass, Object salt) 56 throws DataAccessException; 57 58 /** 59 * <p>Validates a specified "raw" password against an encoded password.</p> 60 * <P>The encoded password should have previously been generated by {@link #encodePassword(String, 61 * Object)}. This method will encode the <code>rawPass</code> (using the optional <code>salt</code>), and then 62 * compared it with the presented <code>encPass</code>.</p> 63 * <p>For a discussion of salts, please refer to {@link #encodePassword(String, Object)}.</p> 64 * 65 * @param encPass a pre-encoded password 66 * @param rawPass a raw password to encode and compare against the pre-encoded password 67 * @param salt optionally used by the implementation to "salt" the raw password before encoding. A 68 * <code>null</code> value is legal. 69 * 70 * @return true if the password is valid , false otherwise 71 * 72 * @throws DataAccessException DOCUMENT ME! 73 */ 74 boolean isPasswordValid(String encPass, String rawPass, Object salt) 75 throws DataAccessException; 76 }