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 java.util.Set; 022import javax.crypto.SecretKey; 023 024import com.nimbusds.jose.*; 025import com.nimbusds.jose.crypto.impl.*; 026import com.nimbusds.jose.util.Base64URL; 027import com.nimbusds.jose.util.StandardCharset; 028import net.jcip.annotations.ThreadSafe; 029 030 031/** 032 * Password-based decrypter of {@link com.nimbusds.jose.JWEObject JWE objects}. 033 * Expects a password. 034 * 035 * <p>See RFC 7518 036 * <a href="https://tools.ietf.org/html/rfc7518#section-4.8">section 4.8</a> 037 * for more information. 038 * 039 * <p>This class is thread-safe. 040 * 041 * <p>Supports the following key management algorithms: 042 * 043 * <ul> 044 * <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS256_A128KW} 045 * <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS384_A192KW} 046 * <li>{@link com.nimbusds.jose.JWEAlgorithm#PBES2_HS512_A256KW} 047 * </ul> 048 * 049 * <p>Supports the following content encryption algorithms: 050 * 051 * <ul> 052 * <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256} 053 * <li>{@link com.nimbusds.jose.EncryptionMethod#A192CBC_HS384} 054 * <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512} 055 * <li>{@link com.nimbusds.jose.EncryptionMethod#A128GCM} 056 * <li>{@link com.nimbusds.jose.EncryptionMethod#A192GCM} 057 * <li>{@link com.nimbusds.jose.EncryptionMethod#A256GCM} 058 * <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256_DEPRECATED} 059 * <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512_DEPRECATED} 060 * </ul> 061 * 062 * @author Vladimir Dzhuvinov 063 * @version 2016-07-26 064 */ 065@ThreadSafe 066public class PasswordBasedDecrypter extends PasswordBasedCryptoProvider implements JWEDecrypter, CriticalHeaderParamsAware { 067 068 069 /** 070 * The critical header policy. 071 */ 072 private final CriticalHeaderParamsDeferral critPolicy = new CriticalHeaderParamsDeferral(); 073 074 075 /** 076 * Creates a new password-based decrypter. 077 * 078 * @param password The password bytes. Must not be empty or 079 * {@code null}. 080 */ 081 public PasswordBasedDecrypter(final byte[] password) { 082 083 super(password); 084 } 085 086 087 /** 088 * Creates a new password-based decrypter. 089 * 090 * @param password The password, as a UTF-8 encoded string. Must not be 091 * empty or {@code null}. 092 */ 093 public PasswordBasedDecrypter(final String password) { 094 095 super(password.getBytes(StandardCharset.UTF_8)); 096 } 097 098 099 @Override 100 public Set<String> getProcessedCriticalHeaderParams() { 101 102 return critPolicy.getProcessedCriticalHeaderParams(); 103 } 104 105 106 @Override 107 public Set<String> getDeferredCriticalHeaderParams() { 108 109 return critPolicy.getProcessedCriticalHeaderParams(); 110 } 111 112 113 @Override 114 public byte[] decrypt(final JWEHeader header, 115 final Base64URL encryptedKey, 116 final Base64URL iv, 117 final Base64URL cipherText, 118 final Base64URL authTag) 119 throws JOSEException { 120 121 // Validate required JWE parts 122 if (encryptedKey == null) { 123 throw new JOSEException("Missing JWE encrypted key"); 124 } 125 126 if (iv == null) { 127 throw new JOSEException("Missing JWE initialization vector (IV)"); 128 } 129 130 if (authTag == null) { 131 throw new JOSEException("Missing JWE authentication tag"); 132 } 133 134 if (header.getPBES2Salt() == null) { 135 throw new JOSEException("Missing JWE \"p2s\" header parameter"); 136 } 137 138 final byte[] salt = header.getPBES2Salt().decode(); 139 140 if (header.getPBES2Count() < 1) { 141 throw new JOSEException("Missing JWE \"p2c\" header parameter"); 142 } 143 144 final int iterationCount = header.getPBES2Count(); 145 146 critPolicy.ensureHeaderPasses(header); 147 148 final JWEAlgorithm alg = header.getAlgorithm(); 149 final byte[] formattedSalt = PBKDF2.formatSalt(alg, salt); 150 final PRFParams prfParams = PRFParams.resolve(alg, getJCAContext().getMACProvider()); 151 final SecretKey psKey = PBKDF2.deriveKey(getPassword(), formattedSalt, iterationCount, prfParams); 152 153 final SecretKey cek = AESKW.unwrapCEK(psKey, encryptedKey.decode(), getJCAContext().getKeyEncryptionProvider()); 154 155 return ContentCryptoProvider.decrypt(header, encryptedKey, iv, cipherText, authTag, cek, getJCAContext()); 156 } 157}