Pbkdf2PasswordEncoder.java
/*
* Copyright 2004-present 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
*
* https://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.password;
import java.security.GeneralSecurityException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import org.springframework.security.crypto.codec.Hex;
import org.springframework.security.crypto.codec.Utf8;
import org.springframework.security.crypto.keygen.BytesKeyGenerator;
import org.springframework.security.crypto.keygen.KeyGenerators;
import org.springframework.security.crypto.util.EncodingUtils;
/**
* A {@link PasswordEncoder} implementation that uses PBKDF2 with :
* <ul>
* <li>a configurable random salt value length (default is {@value #DEFAULT_SALT_LENGTH}
* bytes)</li>
* <li>a configurable number of iterations (default is {@value #DEFAULT_ITERATIONS})</li>
* <li>a configurable key derivation function (see {@link SecretKeyFactoryAlgorithm})</li>
* <li>a configurable secret appended to the random salt (default is empty)</li>
* </ul>
* The algorithm is invoked on the concatenated bytes of the salt, secret and password.
*
* @author Rob Worsnop
* @author Rob Winch
* @author Lo��c Guibert
* @since 4.1
*/
public class Pbkdf2PasswordEncoder extends AbstractValidatingPasswordEncoder {
private static final int DEFAULT_SALT_LENGTH = 16;
private static final SecretKeyFactoryAlgorithm DEFAULT_ALGORITHM = SecretKeyFactoryAlgorithm.PBKDF2WithHmacSHA256;
private static final int DEFAULT_HASH_WIDTH = 256; // SHA-256
private static final int DEFAULT_ITERATIONS = 310000;
private final BytesKeyGenerator saltGenerator;
private final byte[] secret;
private final int iterations;
private String algorithm = DEFAULT_ALGORITHM.name();
private int hashWidth = DEFAULT_HASH_WIDTH;
// @formatter:off
/*
The length of the hash should be derived from the hashing algorithm.
For example:
SHA-1 - 160 bits (20 bytes)
SHA-256 - 256 bits (32 bytes)
SHA-512 - 512 bits (64 bytes)
However, the original configuration for PBKDF2 was hashWidth=256 and algorithm=SHA-1, which is incorrect.
The default configuration has been updated to hashWidth=256 and algorithm=SHA-256 (see gh-10506).
In order to preserve backwards compatibility, the variable 'overrideHashWidth' has been introduced
to indicate usage of the deprecated constructor that honors the hashWidth parameter.
*/
// @formatter:on
private boolean overrideHashWidth = true;
private boolean encodeHashAsBase64;
/**
* Constructs a PBKDF2 password encoder with a secret value as well as salt length,
* iterations and hash width.
* @param secret the secret
* @param saltLength the salt length (in bytes)
* @param iterations the number of iterations. Users should aim for taking about .5
* seconds on their own system.
* @param hashWidth the size of the hash (in bits)
* @since 5.5
* @deprecated Use
* {@link #Pbkdf2PasswordEncoder(CharSequence, int, int, SecretKeyFactoryAlgorithm)}
* instead
*/
@Deprecated
public Pbkdf2PasswordEncoder(CharSequence secret, int saltLength, int iterations, int hashWidth) {
this.secret = Utf8.encode(secret);
this.saltGenerator = KeyGenerators.secureRandom(saltLength);
this.iterations = iterations;
this.hashWidth = hashWidth;
this.algorithm = SecretKeyFactoryAlgorithm.PBKDF2WithHmacSHA1.name();
this.overrideHashWidth = false; // Honor 'hashWidth' to preserve backwards
// compatibility
}
/**
* Constructs a PBKDF2 password encoder with a secret value as well as salt length,
* iterations and algorithm.
* @param secret the secret
* @param saltLength the salt length (in bytes)
* @param iterations the number of iterations. Users should aim for taking about .5
* seconds on their own system.
* @param secretKeyFactoryAlgorithm the algorithm to use
* @since 5.8
*/
public Pbkdf2PasswordEncoder(CharSequence secret, int saltLength, int iterations,
SecretKeyFactoryAlgorithm secretKeyFactoryAlgorithm) {
this.secret = Utf8.encode(secret);
this.saltGenerator = KeyGenerators.secureRandom(saltLength);
this.iterations = iterations;
setAlgorithm(secretKeyFactoryAlgorithm);
}
/**
* Constructs a PBKDF2 password encoder with no additional secret value. There will be
* a salt length of 8 bytes, 185,000 iterations, SHA-1 algorithm and a hash length of
* 256 bits. The default is based upon aiming for .5 seconds to validate the password
* when this class was added. Users should tune password verification to their own
* systems.
* @return the {@link Pbkdf2PasswordEncoder}
* @since 5.8
* @deprecated Use {@link #defaultsForSpringSecurity_v5_8()} instead
*/
@Deprecated
public static Pbkdf2PasswordEncoder defaultsForSpringSecurity_v5_5() {
return new Pbkdf2PasswordEncoder("", 8, 185000, 256);
}
/**
* Constructs a PBKDF2 password encoder with no additional secret value. There will be
* a salt length of 16 bytes, 310,000 iterations, SHA-256 algorithm and a hash length
* of 256 bits. The default is based upon aiming for .5 seconds to validate the
* password when this class was added. Users should tune password verification to
* their own systems.
* @return the {@link Pbkdf2PasswordEncoder}
* @since 5.8
*/
public static Pbkdf2PasswordEncoder defaultsForSpringSecurity_v5_8() {
return new Pbkdf2PasswordEncoder("", DEFAULT_SALT_LENGTH, DEFAULT_ITERATIONS, DEFAULT_ALGORITHM);
}
/**
* Sets the algorithm to use. See <a href=
* "https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#SecretKeyFactory">SecretKeyFactory
* Algorithms</a>
* @param secretKeyFactoryAlgorithm the algorithm to use (i.e.
* {@code SecretKeyFactoryAlgorithm.PBKDF2WithHmacSHA1},
* {@code SecretKeyFactoryAlgorithm.PBKDF2WithHmacSHA256},
* {@code SecretKeyFactoryAlgorithm.PBKDF2WithHmacSHA512})
* @since 5.0
*/
public void setAlgorithm(SecretKeyFactoryAlgorithm secretKeyFactoryAlgorithm) {
if (secretKeyFactoryAlgorithm == null) {
throw new IllegalArgumentException("secretKeyFactoryAlgorithm cannot be null");
}
String algorithmName = secretKeyFactoryAlgorithm.name();
try {
SecretKeyFactory.getInstance(algorithmName);
this.algorithm = algorithmName;
}
catch (NoSuchAlgorithmException ex) {
throw new IllegalArgumentException("Invalid algorithm '" + algorithmName + "'.", ex);
}
if (this.overrideHashWidth) {
this.hashWidth = SecretKeyFactoryAlgorithm.PBKDF2WithHmacSHA1.equals(secretKeyFactoryAlgorithm) ? 160
: SecretKeyFactoryAlgorithm.PBKDF2WithHmacSHA256.equals(secretKeyFactoryAlgorithm) ? 256 : 512;
}
}
/**
* Sets if the resulting hash should be encoded as Base64. The default is false which
* means it will be encoded in Hex.
* @param encodeHashAsBase64 true if encode as Base64, false if should use Hex
* (default)
*/
public void setEncodeHashAsBase64(boolean encodeHashAsBase64) {
this.encodeHashAsBase64 = encodeHashAsBase64;
}
@Override
protected String encodeNonNullPassword(String rawPassword) {
byte[] salt = this.saltGenerator.generateKey();
byte[] encoded = encodedNonNullPassword(rawPassword, salt);
return encodedNonNullPassword(encoded);
}
private String encodedNonNullPassword(byte[] bytes) {
if (this.encodeHashAsBase64) {
return Base64.getEncoder().encodeToString(bytes);
}
return String.valueOf(Hex.encode(bytes));
}
@Override
protected boolean matchesNonNull(String rawPassword, String encodedPassword) {
byte[] digested = decode(encodedPassword);
byte[] salt = EncodingUtils.subArray(digested, 0, this.saltGenerator.getKeyLength());
return MessageDigest.isEqual(digested, encodedNonNullPassword(rawPassword, salt));
}
private byte[] decode(String encodedBytes) {
if (this.encodeHashAsBase64) {
return Base64.getDecoder().decode(encodedBytes);
}
return Hex.decode(encodedBytes);
}
private byte[] encodedNonNullPassword(CharSequence rawPassword, byte[] salt) {
try {
PBEKeySpec spec = new PBEKeySpec(rawPassword.toString().toCharArray(),
EncodingUtils.concatenate(salt, this.secret), this.iterations, this.hashWidth);
SecretKeyFactory skf = SecretKeyFactory.getInstance(this.algorithm);
return EncodingUtils.concatenate(salt, skf.generateSecret(spec).getEncoded());
}
catch (GeneralSecurityException ex) {
throw new IllegalStateException("Could not create hash", ex);
}
}
/**
* The Algorithm used for creating the {@link SecretKeyFactory}
*
* @since 5.0
*/
public enum SecretKeyFactoryAlgorithm {
PBKDF2WithHmacSHA1, PBKDF2WithHmacSHA256, PBKDF2WithHmacSHA512
}
}