PasswordBasedEncrypter.java
/*
* nimbus-jose-jwt
*
* Copyright 2012-2016, Connect2id Ltd.
*
* 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 com.nimbusds.jose.crypto;
import java.util.Arrays;
import javax.crypto.SecretKey;
import com.nimbusds.jose.*;
import com.nimbusds.jose.crypto.impl.*;
import com.nimbusds.jose.util.Base64URL;
import com.nimbusds.jose.util.StandardCharset;
import net.jcip.annotations.ThreadSafe;
/**
* Password-based encrypter of {@link com.nimbusds.jose.JWEObject JWE objects}.
* Expects a password.
*
* <p>See RFC 7518
* <a href="https://tools.ietf.org/html/rfc7518#section-4.8">section 4.8</a>
* for more information.
*
* <p>This class is thread-safe.
*
* <p>Supports the following key management algorithms:
*
* <ul>
* <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS256_A128KW}
* <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS384_A192KW}
* <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS512_A256KW}
* </ul>
*
* <p>Supports the following content encryption algorithms:
*
* <ul>
* <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A192CBC_HS384}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A128GCM}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A192GCM}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A256GCM}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256_DEPRECATED}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512_DEPRECATED}
* <li>{@link com.nimbusds.jose.EncryptionMethod#XC20P}
* </ul>
*
* @author Vladimir Dzhuvinov
* @author Egor Puzanov
* @version 2023-09-10
*/
@ThreadSafe
public class PasswordBasedEncrypter extends PasswordBasedCryptoProvider implements JWEEncrypter {
/**
* The minimum salt length (8 bytes).
*/
public static final int MIN_SALT_LENGTH = PBKDF2.MIN_SALT_LENGTH;
/**
* The cryptographic salt length, in bytes.
*/
private final int saltLength;
/**
* The minimum recommended iteration count (1000).
*/
public static final int MIN_RECOMMENDED_ITERATION_COUNT = 1000;
/**
* The iteration count.
*/
private final int iterationCount;
/**
* Creates a new password-based encrypter.
*
* @param password The password bytes. Must not be empty or
* {@code null}.
* @param saltLength The length of the generated cryptographic
* salts, in bytes. Must be at least 8 bytes.
* @param iterationCount The pseudo-random function (PRF) iteration
* count. Must be at least 1000.
*/
public PasswordBasedEncrypter(final byte[] password,
final int saltLength,
final int iterationCount) {
super(password);
if (saltLength < MIN_SALT_LENGTH) {
throw new IllegalArgumentException("The minimum salt length (p2s) is " + MIN_SALT_LENGTH + " bytes");
}
this.saltLength = saltLength;
if (iterationCount < MIN_RECOMMENDED_ITERATION_COUNT) {
throw new IllegalArgumentException("The minimum recommended iteration count (p2c) is " + MIN_RECOMMENDED_ITERATION_COUNT);
}
this.iterationCount = iterationCount;
}
/**
* Creates a new password-based encrypter.
*
* @param password The password, as a UTF-8 encoded string. Must
* not be empty or {@code null}.
* @param saltLength The length of the generated cryptographic
* salts, in bytes. Must be at least 8 bytes.
* @param iterationCount The pseudo-random function (PRF) iteration
* count. Must be at least 1000.
*/
public PasswordBasedEncrypter(final String password,
final int saltLength,
final int iterationCount) {
this(password.getBytes(StandardCharset.UTF_8), saltLength, iterationCount);
}
/**
* Encrypts the specified clear text of a {@link JWEObject JWE object}.
*
* @param header The JSON Web Encryption (JWE) header. Must specify
* a supported JWE algorithm and method. Must not be
* {@code null}.
* @param clearText The clear text to encrypt. Must not be {@code null}.
*
* @return The resulting JWE crypto parts.
*
* @throws JOSEException If the JWE algorithm or method is not
* supported or if encryption failed for some
* other internal reason.
*/
@Deprecated
public JWECryptoParts encrypt(final JWEHeader header, final byte[] clearText)
throws JOSEException {
return encrypt(header, clearText, AAD.compute(header));
}
@Override
public JWECryptoParts encrypt(final JWEHeader header, final byte[] clearText, final byte[] aad)
throws JOSEException {
final JWEAlgorithm alg = JWEHeaderValidation.getAlgorithmAndEnsureNotNull(header);
final EncryptionMethod enc = header.getEncryptionMethod();
final byte[] salt = new byte[saltLength];
getJCAContext().getSecureRandom().nextBytes(salt);
final byte[] formattedSalt = PBKDF2.formatSalt(alg, salt);
final PRFParams prfParams = PRFParams.resolve(alg, getJCAContext().getMACProvider());
final SecretKey psKey = PBKDF2.deriveKey(getPassword(), formattedSalt, iterationCount, prfParams);
// We need to work on the header
final JWEHeader updatedHeader = new JWEHeader.Builder(header).
pbes2Salt(Base64URL.encode(salt)).
pbes2Count(iterationCount).
build();
final SecretKey cek = ContentCryptoProvider.generateCEK(enc, getJCAContext().getSecureRandom());
// The second JWE part
final Base64URL encryptedKey = Base64URL.encode(AESKW.wrapCEK(cek, psKey, getJCAContext().getKeyEncryptionProvider()));
// for JWEObject we need update the AAD as well
final byte[] updatedAAD = Arrays.equals(AAD.compute(header), aad) ? AAD.compute(updatedHeader) : aad;
return ContentCryptoProvider.encrypt(updatedHeader, clearText, updatedAAD, cek, encryptedKey, getJCAContext());
}
/**
* Returns the length of the generated cryptographic salts.
*
* @return The length of the generated cryptographic salts, in bytes.
*/
public int getSaltLength() {
return saltLength;
}
/**
* Returns the pseudo-random function (PRF) iteration count.
*
* @return The iteration count.
*/
public int getIterationCount() {
return iterationCount;
}
}