/*
 * Copyright 2002-2017 the original author or authors.
 *
 * 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.crypto.factory;

import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.DelegatingPasswordEncoder;
import org.springframework.security.crypto.password.LdapShaPasswordEncoder;
import org.springframework.security.crypto.password.Md4PasswordEncoder;
import org.springframework.security.crypto.password.MessageDigestPasswordEncoder;
import org.springframework.security.crypto.password.NoOpPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.crypto.password.Pbkdf2PasswordEncoder;
import org.springframework.security.crypto.password.StandardPasswordEncoder;
import org.springframework.security.crypto.scrypt.SCryptPasswordEncoder;

import java.util.HashMap;
import java.util.Map;

/**
 * Used for creating {@link PasswordEncoder} instances
 * @author Rob Winch
 * @since 5.0
 */
public class PasswordEncoderFactories {

	/**
	 * Creates a {@link DelegatingPasswordEncoder} with default mappings. Additional
	 * mappings may be added and the encoding will be updated to conform with best
	 * practices. However, due to the nature of {@link DelegatingPasswordEncoder} the
	 * updates should not impact users. The mappings current are:
	 *
	 * <ul>
	 * <li>bcrypt - {@link BCryptPasswordEncoder} (Also used for encoding)</li>
	 * <li>ldap - {@link LdapShaPasswordEncoder}</li>
	 * <li>MD4 - {@link Md4PasswordEncoder}</li>
	 * <li>MD5 - {@code new MessageDigestPasswordEncoder("MD5")}</li>
	 * <li>noop - {@link NoOpPasswordEncoder}</li>
	 * <li>pbkdf2 - {@link Pbkdf2PasswordEncoder}</li>
	 * <li>scrypt - {@link SCryptPasswordEncoder}</li>
	 * <li>SHA-1 - {@code new MessageDigestPasswordEncoder("SHA-1")}</li>
	 * <li>SHA-256 - {@code new MessageDigestPasswordEncoder("SHA-256")}</li>
	 * <li>sha256 - {@link StandardPasswordEncoder}</li>
	 * </ul>
	 *
	 * @return the {@link PasswordEncoder} to use
	 */
	public static PasswordEncoder createDelegatingPasswordEncoder() {
		String encodingId = "bcrypt";
		Map<String, PasswordEncoder> encoders = new HashMap<>();
		encoders.put(encodingId, new BCryptPasswordEncoder());
		encoders.put("ldap", new LdapShaPasswordEncoder());
		encoders.put("MD4", new Md4PasswordEncoder());
		encoders.put("MD5", new MessageDigestPasswordEncoder("MD5"));
		encoders.put("noop", NoOpPasswordEncoder.getInstance());
		encoders.put("pbkdf2", new Pbkdf2PasswordEncoder());
		encoders.put("scrypt", new SCryptPasswordEncoder());
		encoders.put("SHA-1", new MessageDigestPasswordEncoder("SHA-1"));
		encoders.put("SHA-256", new MessageDigestPasswordEncoder("SHA-256"));
		encoders.put("sha256", new StandardPasswordEncoder());

		return new DelegatingPasswordEncoder(encodingId, encoders);
	}

	private PasswordEncoderFactories() {}
}
