001/* 002 * nimbus-jose-jwt 003 * 004 * Copyright 2012-2016, Connect2id Ltd. 005 * 006 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use 007 * this file except in compliance with the License. You may obtain a copy of the 008 * License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software distributed 013 * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 014 * CONDITIONS OF ANY KIND, either express or implied. See the License for the 015 * specific language governing permissions and limitations under the License. 016 */ 017 018package com.nimbusds.jose.crypto; 019 020 021import javax.crypto.SecretKey; 022 023import com.nimbusds.jose.*; 024import com.nimbusds.jose.crypto.impl.*; 025import com.nimbusds.jose.util.Base64URL; 026import com.nimbusds.jose.util.StandardCharset; 027import net.jcip.annotations.ThreadSafe; 028 029 030/** 031 * Password-based encrypter of {@link com.nimbusds.jose.JWEObject JWE objects}. 032 * Expects a password. 033 * 034 * <p>See RFC 7518 035 * <a href="https://tools.ietf.org/html/rfc7518#section-4.8">section 4.8</a> 036 * for more information. 037 * 038 * <p>This class is thread-safe. 039 * 040 * <p>Supports the following key management algorithms: 041 * 042 * <ul> 043 * <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS256_A128KW} 044 * <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS384_A192KW} 045 * <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS512_A256KW} 046 * </ul> 047 * 048 * <p>Supports the following content encryption algorithms: 049 * 050 * <ul> 051 * <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256} 052 * <li>{@link com.nimbusds.jose.EncryptionMethod#A192CBC_HS384} 053 * <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512} 054 * <li>{@link com.nimbusds.jose.EncryptionMethod#A128GCM} 055 * <li>{@link com.nimbusds.jose.EncryptionMethod#A192GCM} 056 * <li>{@link com.nimbusds.jose.EncryptionMethod#A256GCM} 057 * <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256_DEPRECATED} 058 * <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512_DEPRECATED} 059 * <li>{@link com.nimbusds.jose.EncryptionMethod#XC20P} 060 * </ul> 061 * 062 * @author Vladimir Dzhuvinov 063 * @version 2021-07-03 064 */ 065@ThreadSafe 066public class PasswordBasedEncrypter extends PasswordBasedCryptoProvider implements JWEEncrypter { 067 068 069 /** 070 * The minimum salt length (8 bytes). 071 */ 072 public static final int MIN_SALT_LENGTH = PBKDF2.MIN_SALT_LENGTH; 073 074 075 /** 076 * The cryptographic salt length, in bytes. 077 */ 078 private final int saltLength; 079 080 081 /** 082 * The minimum recommended iteration count (1000). 083 */ 084 public static final int MIN_RECOMMENDED_ITERATION_COUNT = 1000; 085 086 087 /** 088 * The iteration count. 089 */ 090 private final int iterationCount; 091 092 093 /** 094 * Creates a new password-based encrypter. 095 * 096 * @param password The password bytes. Must not be empty or 097 * {@code null}. 098 * @param saltLength The length of the generated cryptographic 099 * salts, in bytes. Must be at least 8 bytes. 100 * @param iterationCount The pseudo-random function (PRF) iteration 101 * count. Must be at least 1000. 102 */ 103 public PasswordBasedEncrypter(final byte[] password, 104 final int saltLength, 105 final int iterationCount) { 106 107 super(password); 108 109 if (saltLength < MIN_SALT_LENGTH) { 110 throw new IllegalArgumentException("The minimum salt length (p2s) is " + MIN_SALT_LENGTH + " bytes"); 111 } 112 113 this.saltLength = saltLength; 114 115 if (iterationCount < MIN_RECOMMENDED_ITERATION_COUNT) { 116 throw new IllegalArgumentException("The minimum recommended iteration count (p2c) is " + MIN_RECOMMENDED_ITERATION_COUNT); 117 } 118 119 this.iterationCount = iterationCount; 120 } 121 122 123 /** 124 * Creates a new password-based encrypter. 125 * 126 * @param password The password, as a UTF-8 encoded string. Must 127 * not be empty or {@code null}. 128 * @param saltLength The length of the generated cryptographic 129 * salts, in bytes. Must be at least 8 bytes. 130 * @param iterationCount The pseudo-random function (PRF) iteration 131 * count. Must be at least 1000. 132 */ 133 public PasswordBasedEncrypter(final String password, 134 final int saltLength, 135 final int iterationCount) { 136 137 this(password.getBytes(StandardCharset.UTF_8), saltLength, iterationCount); 138 } 139 140 141 @Override 142 public JWECryptoParts encrypt(final JWEHeader header, final byte[] clearText) 143 throws JOSEException { 144 145 final JWEAlgorithm alg = header.getAlgorithm(); 146 final EncryptionMethod enc = header.getEncryptionMethod(); 147 148 final byte[] salt = new byte[saltLength]; 149 getJCAContext().getSecureRandom().nextBytes(salt); 150 final byte[] formattedSalt = PBKDF2.formatSalt(alg, salt); 151 final PRFParams prfParams = PRFParams.resolve(alg, getJCAContext().getMACProvider()); 152 final SecretKey psKey = PBKDF2.deriveKey(getPassword(), formattedSalt, iterationCount, prfParams); 153 154 // We need to work on the header 155 final JWEHeader updatedHeader = new JWEHeader.Builder(header). 156 pbes2Salt(Base64URL.encode(salt)). 157 pbes2Count(iterationCount). 158 build(); 159 160 final SecretKey cek = ContentCryptoProvider.generateCEK(enc, getJCAContext().getSecureRandom()); 161 162 // The second JWE part 163 final Base64URL encryptedKey = Base64URL.encode(AESKW.wrapCEK(cek, psKey, getJCAContext().getKeyEncryptionProvider())); 164 165 return ContentCryptoProvider.encrypt(updatedHeader, clearText, cek, encryptedKey, getJCAContext()); 166 } 167 168 169 /** 170 * Returns the length of the generated cryptographic salts. 171 * 172 * @return The length of the generated cryptographic salts, in bytes. 173 */ 174 public int getSaltLength() { 175 176 return saltLength; 177 } 178 179 180 /** 181 * Returns the pseudo-random function (PRF) iteration count. 182 * 183 * @return The iteration count. 184 */ 185 public int getIterationCount() { 186 187 return iterationCount; 188 } 189}