001/*
002 * nimbus-jose-jwt
003 *
004 * Copyright 2012-2016, Connect2id Ltd and contributors.
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.impl;
019
020
021import com.nimbusds.jose.JOSEException;
022import net.jcip.annotations.ThreadSafe;
023
024import javax.crypto.Cipher;
025import javax.crypto.IllegalBlockSizeException;
026import javax.crypto.SecretKey;
027import javax.crypto.spec.OAEPParameterSpec;
028import javax.crypto.spec.PSource;
029import javax.crypto.spec.SecretKeySpec;
030import java.security.AlgorithmParameters;
031import java.security.PrivateKey;
032import java.security.Provider;
033import java.security.interfaces.RSAPublicKey;
034import java.security.spec.AlgorithmParameterSpec;
035import java.security.spec.MGF1ParameterSpec;
036
037
038/**
039 * RSAES OAEP (SHA-512) methods for Content Encryption Key (CEK) encryption and
040 * decryption. Uses the BouncyCastle.org provider. This class is thread-safe
041 *
042 * @author Vladimir Dzhuvinov
043 * @author Justin Richer
044 * @author Peter Laurina (adapted from RSA_OAEP_256)
045 * @version 2021-09-01
046 */
047@ThreadSafe
048public class RSA_OAEP_512 {
049
050        private static MGF1ParameterSpec mgf1ParameterSpec = MGF1ParameterSpec.SHA512;
051        /**
052         * The JCA algorithm name for RSA-OAEP-512.
053         */
054        private static final String RSA_OEAP_512_JCA_ALG = "RSA/ECB/OAEPWithSHA-512AndMGF1Padding";
055
056
057        /**
058         * Encrypts the specified Content Encryption Key (CEK).
059         *
060         * @param pub      The public RSA key. Must not be {@code null}.
061         * @param cek      The Content Encryption Key (CEK) to encrypt. Must
062         *                 not be {@code null}.
063         * @param provider The JCA provider, or {@code null} to use the default
064         *                 one.
065         *
066         * @return The encrypted Content Encryption Key (CEK).
067         *
068         * @throws JOSEException If encryption failed.
069         */
070        public static byte[] encryptCEK(final RSAPublicKey pub, final SecretKey cek, final Provider provider)
071                throws JOSEException {
072
073                try {
074                        AlgorithmParameters algp = AlgorithmParametersHelper.getInstance("OAEP", provider);
075                        AlgorithmParameterSpec paramSpec = new OAEPParameterSpec("SHA-512", "MGF1", mgf1ParameterSpec, PSource.PSpecified.DEFAULT);
076                        algp.init(paramSpec);
077                        Cipher cipher = CipherHelper.getInstance(RSA_OEAP_512_JCA_ALG, provider);
078                        cipher.init(Cipher.ENCRYPT_MODE, pub, algp);
079                        return cipher.doFinal(cek.getEncoded());
080
081                } catch (IllegalBlockSizeException e) {
082                        throw new JOSEException("RSA block size exception: The RSA key is too short, try a longer one", e);
083                } catch (Exception e) {
084                        // java.security.NoSuchAlgorithmException
085                        // java.security.NoSuchPaddingException
086                        // java.security.InvalidKeyException
087                        // javax.crypto.BadPaddingException
088                        throw new JOSEException(e.getMessage(), e);
089                }
090        }
091
092
093        /**
094         * Decrypts the specified encrypted Content Encryption Key (CEK).
095         *
096         * @param priv         The private RSA key. Must not be {@code null}.
097         * @param encryptedCEK The encrypted Content Encryption Key (CEK) to
098         *                     decrypt. Must not be {@code null}.
099         * @param provider     The JCA provider, or {@code null} to use the
100         *                     default one.
101         *
102         * @return The decrypted Content Encryption Key (CEK).
103         *
104         * @throws JOSEException If decryption failed.
105         */
106        public static SecretKey decryptCEK(final PrivateKey priv,
107                                           final byte[] encryptedCEK, final Provider provider)
108                throws JOSEException {
109
110                try {
111                        AlgorithmParameters algp = AlgorithmParametersHelper.getInstance("OAEP", provider);
112                        AlgorithmParameterSpec paramSpec = new OAEPParameterSpec("SHA-512", "MGF1", mgf1ParameterSpec, PSource.PSpecified.DEFAULT);
113                        algp.init(paramSpec);
114                        Cipher cipher = CipherHelper.getInstance(RSA_OEAP_512_JCA_ALG, provider);
115                        cipher.init(Cipher.DECRYPT_MODE, priv, algp);
116                        return new SecretKeySpec(cipher.doFinal(encryptedCEK), "AES");
117
118                } catch (Exception e) {
119                        // java.security.NoSuchAlgorithmException
120                        // java.security.NoSuchPaddingException
121                        // java.security.InvalidKeyException
122                        // javax.crypto.IllegalBlockSizeException
123                        // javax.crypto.BadPaddingException
124                        throw new JOSEException(e.getMessage(), e);
125                }
126        }
127
128
129        /**
130         * Prevents public instantiation.
131         */
132        private RSA_OAEP_512() { }
133}