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.security.InvalidKeyException;
022import java.security.PrivateKey;
023import java.security.Signature;
024import java.security.SignatureException;
025import java.util.Collections;
026import java.util.Set;
027
028import static com.nimbusds.jose.jwk.gen.RSAKeyGenerator.MIN_KEY_SIZE_BITS;
029
030import net.jcip.annotations.ThreadSafe;
031
032import com.nimbusds.jose.*;
033import com.nimbusds.jose.crypto.impl.RSAKeyUtils;
034import com.nimbusds.jose.crypto.impl.RSASSA;
035import com.nimbusds.jose.crypto.impl.RSASSAProvider;
036import com.nimbusds.jose.crypto.opts.AllowWeakRSAKey;
037import com.nimbusds.jose.crypto.opts.OptionUtils;
038import com.nimbusds.jose.crypto.opts.UserAuthenticationRequired;
039import com.nimbusds.jose.jwk.RSAKey;
040import com.nimbusds.jose.util.Base64URL;
041
042
043
044/**
045 * RSA Signature-Scheme-with-Appendix (RSASSA) signer of 
046 * {@link com.nimbusds.jose.JWSObject JWS objects}. Expects a private RSA key.
047 *
048 * <p>See RFC 7518, sections
049 * <a href="https://tools.ietf.org/html/rfc7518#section-3.3">3.3</a> and
050 * <a href="https://tools.ietf.org/html/rfc7518#section-3.5">3.5</a> for more
051 * information.
052 *
053 * <p>This class is thread-safe.
054 *
055 * <p>Supports the following algorithms:
056 *
057 * <ul>
058 *     <li>{@link com.nimbusds.jose.JWSAlgorithm#RS256}
059 *     <li>{@link com.nimbusds.jose.JWSAlgorithm#RS384}
060 *     <li>{@link com.nimbusds.jose.JWSAlgorithm#RS512}
061 *     <li>{@link com.nimbusds.jose.JWSAlgorithm#PS256}
062 *     <li>{@link com.nimbusds.jose.JWSAlgorithm#PS384}
063 *     <li>{@link com.nimbusds.jose.JWSAlgorithm#PS512}
064 * </ul>
065 *
066 * <p>Supports the following {@link JWSSignerOption options}:
067 *
068 * <ul>
069 *     <li>{@link UserAuthenticationRequired} -- to prompt the user to
070 *         authenticate in order to complete the signing operation. Android
071 *         applications can use this option to trigger a biometric prompt that
072 *         is required to unlock a private key created with
073 *         {@code setUserAuthenticationRequired(true)}.
074 *     <li>{@link AllowWeakRSAKey} -- to allow weak RSA keys that are shorter
075 *         than {@link com.nimbusds.jose.jwk.gen.RSAKeyGenerator#MIN_KEY_SIZE_BITS
076 *         2048 bits}
077 * </ul>
078 *
079 * <p>Supports the
080 * {@link com.nimbusds.jose.crypto.bc.BouncyCastleFIPSProviderSingleton
081 * BouncyCastle FIPS provider} for the PSxxx family of JWS algorithms.
082 * 
083 * @author Vladimir Dzhuvinov
084 * @author Omer Levi Hevroni
085 * @version 2020-12-27
086 */
087@ThreadSafe
088public class RSASSASigner extends RSASSAProvider implements JWSSigner {
089
090
091        /**
092         * The private RSA key. Represented by generic private key interface to
093         * support key stores that prevent exposure of the private key
094         * parameters via the {@link java.security.interfaces.RSAPrivateKey}
095         * API.
096         *
097         * See https://bitbucket.org/connect2id/nimbus-jose-jwt/issues/169
098         */
099        private final PrivateKey privateKey;
100        
101        
102        /**
103         * The configured options, empty set if none.
104         */
105        private final Set<JWSSignerOption> opts;
106
107
108        /**
109         * Creates a new RSA Signature-Scheme-with-Appendix (RSASSA) signer.
110         * This constructor can also accept a private RSA key located in a
111         * PKCS#11 store that doesn't expose the private key parameters (such
112         * as a smart card or HSM).
113         *
114         * @param privateKey The private RSA key. Its algorithm must be "RSA"
115         *                   and its length at least 2048 bits. Note that the
116         *                   length of an RSA key in a PKCS#11 store cannot be
117         *                   checked. Must not be {@code null}.
118         */
119        public RSASSASigner(final PrivateKey privateKey) {
120
121                this(privateKey, false);
122        }
123
124
125        /**
126         * Creates a new RSA Signature-Scheme-with-Appendix (RSASSA) signer.
127         * This constructor can also accept a private RSA key located in a
128         * PKCS#11 store that doesn't expose the private key parameters (such
129         * as a smart card or HSM).
130         *
131         * @param privateKey   The private RSA key. Its algorithm must be
132         *                     "RSA" and its length at least 2048 bits. Note
133         *                     that the length of an RSA key in a PKCS#11 store
134         *                     cannot be checked. Must not be {@code null}.
135         * @param allowWeakKey {@code true} to allow an RSA key shorter than
136         *                     2048 bits.
137         */
138        @Deprecated
139        public RSASSASigner(final PrivateKey privateKey, final boolean allowWeakKey) {
140
141                this(privateKey, allowWeakKey ? Collections.singleton((JWSSignerOption) AllowWeakRSAKey.getInstance()) : Collections.<JWSSignerOption>emptySet());
142        }
143
144
145        /**
146         * Creates a new RSA Signature-Scheme-with-Appendix (RSASSA) signer.
147         * This constructor can also accept a private RSA key located in a
148         * PKCS#11 store that doesn't expose the private key parameters (such
149         * as a smart card or HSM).
150         *
151         * @param privateKey The private RSA key. Its algorithm must be "RSA"
152         *                   and its length at least 2048 bits. Note that the
153         *                   length of an RSA key in a PKCS#11 store cannot be
154         *                   checked. Must not be {@code null}.
155         * @param opts       The signing options, empty or {@code null} if
156         *                   none.
157         */
158        public RSASSASigner(final PrivateKey privateKey, final Set<JWSSignerOption> opts) {
159                
160                if (! "RSA".equalsIgnoreCase(privateKey.getAlgorithm())) {
161                        throw new IllegalArgumentException("The private key algorithm must be RSA");
162                }
163                
164                this.privateKey = privateKey;
165                
166                this.opts = opts != null ? opts : Collections.<JWSSignerOption>emptySet();
167                
168                if (! OptionUtils.optionIsPresent(this.opts, AllowWeakRSAKey.class)) {
169                        int keyBitLength = RSAKeyUtils.keyBitLength(privateKey);
170                        
171                        if (keyBitLength > 0 && keyBitLength < MIN_KEY_SIZE_BITS) {
172                                throw new IllegalArgumentException("The RSA key size must be at least " + MIN_KEY_SIZE_BITS + " bits");
173                        }
174                }
175        }
176
177
178        /**
179         * Creates a new RSA Signature-Scheme-with-Appendix (RSASSA) signer.
180         *
181         * @param rsaJWK The RSA JSON Web Key (JWK). Must contain or reference
182         *               a private part. Its length must be at least 2048 bits.
183         *               Note that the length of an RSA key in a PKCS#11 store
184         *               cannot be checked. Must not be {@code null}.
185         *
186         * @throws JOSEException If the RSA JWK doesn't contain a private part
187         *                       or its extraction failed.
188         */
189        public RSASSASigner(final RSAKey rsaJWK)
190                throws JOSEException {
191
192                this(RSAKeyUtils.toRSAPrivateKey(rsaJWK));
193        }
194
195
196        /**
197         * Creates a new RSA Signature-Scheme-with-Appendix (RSASSA) signer.
198         *
199         * @param rsaJWK       The RSA JSON Web Key (JWK). Must contain or
200         *                     reference a private part. Its length must be at
201         *                     least 2048 bits. Note that the length of an RSA
202         *                     key in a PKCS#11 store cannot be checked. Must
203         *                     not be {@code null}.
204         * @param allowWeakKey {@code true} to allow an RSA key shorter than
205         *                     2048 bits.
206         *
207         * @throws JOSEException If the RSA JWK doesn't contain a private part
208         *                       or its extraction failed.
209         */
210        @Deprecated
211        public RSASSASigner(final RSAKey rsaJWK, final boolean allowWeakKey)
212                throws JOSEException {
213
214                this(RSAKeyUtils.toRSAPrivateKey(rsaJWK), allowWeakKey);
215        }
216
217
218        /**
219         * Gets the private RSA key.
220         *
221         * @return The private RSA key. Casting to
222         *         {@link java.security.interfaces.RSAPrivateKey} may not be
223         *         possible if the key is located in a PKCS#11 store that
224         *         doesn't expose the private key parameters.
225         */
226        public PrivateKey getPrivateKey() {
227
228                return privateKey;
229        }
230
231
232        @Override
233        public Base64URL sign(final JWSHeader header, final byte[] signingInput)
234                throws JOSEException {
235
236                final Signature signer = getInitiatedSignature(header);
237                
238                if (OptionUtils.optionIsPresent(opts, UserAuthenticationRequired.class)) {
239                        
240                        throw new ActionRequiredForJWSCompletionException(
241                                "Authenticate user to complete signing",
242                                UserAuthenticationRequired.getInstance(),
243                                new CompletableJWSObjectSigning() {
244                                        @Override
245                                        public Base64URL complete() throws JOSEException {
246                                                return sign(signingInput, signer);
247                                        }
248                                }
249                        );
250                }
251                
252                return sign(signingInput, signer);
253        }
254        
255        
256        private Signature getInitiatedSignature(final JWSHeader header)
257                throws JOSEException {
258                
259                Signature signer = RSASSA.getSignerAndVerifier(header.getAlgorithm(), getJCAContext().getProvider());
260                try {
261                        signer.initSign(privateKey);
262                } catch (InvalidKeyException e) {
263                        throw new JOSEException("Invalid private RSA key: " + e.getMessage(), e);
264                }
265                
266                return signer;
267        }
268        
269        
270        private Base64URL sign(final byte[] signingInput, final Signature signer)
271                throws JOSEException {
272                
273                try {
274                        signer.update(signingInput);
275                        return Base64URL.encode(signer.sign());
276                } catch (SignatureException e) {
277                        throw new JOSEException("RSA signature exception: " + e.getMessage(), e);
278                }
279        }
280}