/*
 * 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;

/**
 * Interface for performing authentication operations on a password.
 *
 * @author colin sampaleanu
 * @deprecated It is recommended to use
 * {@link org.springframework.security.crypto.password.PasswordEncoder} instead which
 * better accommodates best practice of randomly generated salt that is included with the
 * password.
 */
@Deprecated
public interface PasswordEncoder {
	// ~ Methods
	// ========================================================================================================

	/**
	 * <p>
	 * Encodes the specified raw password with an implementation specific algorithm.
	 * </p>
	 * <P>
	 * This will generally be a one-way message digest such as MD5 or SHA, but may also be
	 * a plaintext variant which does no encoding at all, but rather returns the same
	 * password it was fed. The latter is useful to plug in when the original password
	 * must be stored as-is.
	 * </p>
	 * <p>
	 * The specified salt will potentially be used by the implementation to "salt" the
	 * initial value before encoding. A salt is usually a user-specific value which is
	 * added to the password before the digest is computed. This means that computation of
	 * digests for common dictionary words will be different than those in the backend
	 * store, because the dictionary word digests will not reflect the addition of the
	 * salt. If a per-user salt is used (rather than a system-wide salt), it also means
	 * users with the same password will have different digest encoded passwords in the
	 * backend store.
	 * </p>
	 * <P>
	 * If a salt value is provided, the same salt value must be use when calling the
	 * {@link #isPasswordValid(String, String, Object)} method. Note that a specific
	 * implementation may choose to ignore the salt value (via <code>null</code>), or
	 * provide its own.
	 * </p>
	 *
	 * @param rawPass the password to encode
	 * @param salt optionally used by the implementation to "salt" the raw password before
	 * encoding. A <code>null</code> value is legal.
	 *
	 * @return encoded password
	 */
	String encodePassword(String rawPass, Object salt);

	/**
	 * <p>
	 * Validates a specified "raw" password against an encoded password.
	 * </p>
	 * <P>
	 * The encoded password should have previously been generated by
	 * {@link #encodePassword(String, Object)}. This method will encode the
	 * <code>rawPass</code> (using the optional <code>salt</code>), and then compared it
	 * with the presented <code>encPass</code>.
	 * </p>
	 * <p>
	 * For a discussion of salts, please refer to {@link #encodePassword(String, Object)}.
	 * </p>
	 *
	 * @param encPass a pre-encoded password
	 * @param rawPass a raw password to encode and compare against the pre-encoded
	 * password
	 * @param salt optionally used by the implementation to "salt" the raw password before
	 * encoding. A <code>null</code> value is legal.
	 *
	 * @return true if the password is valid , false otherwise
	 */
	boolean isPasswordValid(String encPass, String rawPass, Object salt);
}
