/*
* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.security.authentication.encoding;
/**
* <p>
* Convenience base for all password encoders.
* </p>
*
* @author Ben Alex
*/
public abstract class BasePasswordEncoder implements PasswordEncoder {
// ~ Methods
// ========================================================================================================
/**
* Used by subclasses to extract the password and salt from a merged
* <code>String</code> created using
* {@link #mergePasswordAndSalt(String,Object,boolean)}.
* <p>
* The first element in the returned array is the password. The second element is the
* salt. The salt array element will always be present, even if no salt was found in
* the <code>mergedPasswordSalt</code> argument.
* </p>
*
* @param mergedPasswordSalt as generated by <code>mergePasswordAndSalt</code>
*
* @return an array, in which the first element is the password and the second the
* salt
*
* @throws IllegalArgumentException if mergedPasswordSalt is null or empty.
*/
protected String[] demergePasswordAndSalt(String mergedPasswordSalt) {
if ((mergedPasswordSalt == null) || "".equals(mergedPasswordSalt)) {
throw new IllegalArgumentException("Cannot pass a null or empty String");
}
String password = mergedPasswordSalt;
String salt = "";
int saltBegins = mergedPasswordSalt.lastIndexOf("{");
if ((saltBegins != -1) && ((saltBegins + 1) < mergedPasswordSalt.length())) {
salt = mergedPasswordSalt.substring(saltBegins + 1,
mergedPasswordSalt.length() - 1);
password = mergedPasswordSalt.substring(0, saltBegins);
}
return new String[] { password, salt };
}
/**
* Used by subclasses to generate a merged password and salt <code>String</code>.
* <P>
* The generated password will be in the form of <code>password{salt}</code>.
* </p>
* <p>
* A <code>null</code> can be passed to either method, and will be handled correctly.
* If the <code>salt</code> is <code>null</code> or empty, the resulting generated
* password will simply be the passed <code>password</code>. The <code>toString</code>
* method of the <code>salt</code> will be used to represent the salt.
* </p>
*
* @param password the password to be used (can be <code>null</code>)
* @param salt the salt to be used (can be <code>null</code>)
* @param strict ensures salt doesn't contain the delimiters
*
* @return a merged password and salt <code>String</code>
*
* @throws IllegalArgumentException if the salt contains '{' or '}' characters.
*/
protected String mergePasswordAndSalt(String password, Object salt, boolean strict) {
if (password == null) {
password = "";
}
if (strict && (salt != null)) {
if ((salt.toString().lastIndexOf("{") != -1)
|| (salt.toString().lastIndexOf("}") != -1)) {
throw new IllegalArgumentException("Cannot use { or } in salt.toString()");
}
}
if ((salt == null) || "".equals(salt)) {
return password;
}
else {
return password + "{" + salt.toString() + "}";
}
}
}