1 /*
2 * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.crypto.provider;
27
28 import java.io.*;
29 import java.util.Objects;
30 import java.math.BigInteger;
31 import java.security.KeyRep;
32 import java.security.PrivateKey;
33 import java.security.InvalidKeyException;
34 import java.security.ProviderException;
35 import javax.crypto.spec.DHParameterSpec;
36 import sun.security.util.*;
37
38 /**
39 * A private key in PKCS#8 format for the Diffie-Hellman key agreement
40 * algorithm.
41 *
42 * @author Jan Luehe
43 *
44 *
45 * @see DHPublicKey
46 * @see java.security.KeyAgreement
47 */
48 final class DHPrivateKey implements PrivateKey,
49 javax.crypto.interfaces.DHPrivateKey, Serializable {
50
51 @java.io.Serial
52 static final long serialVersionUID = 7565477590005668886L;
53
54 // only supported version of PKCS#8 PrivateKeyInfo
55 private static final BigInteger PKCS8_VERSION = BigInteger.ZERO;
56
57 // the private key
58 private BigInteger x;
59
60 // the key bytes, without the algorithm information
61 private byte[] key;
62
63 // the encoded key
64 private byte[] encodedKey;
65
66 // the prime modulus
67 private BigInteger p;
68
69 // the base generator
70 private BigInteger g;
71
72 // the private-value length (optional)
73 private int l;
74
75 /**
76 * Make a DH private key out of a private value <code>x</code>, a prime
77 * modulus <code>p</code>, and a base generator <code>g</code>.
78 *
79 * @param x the private value
80 * @param p the prime modulus
81 * @param g the base generator
82 *
83 * @exception ProviderException if the key cannot be encoded
84 */
85 DHPrivateKey(BigInteger x, BigInteger p, BigInteger g)
86 throws InvalidKeyException {
87 this(x, p, g, 0);
88 }
89
90 /**
91 * Make a DH private key out of a private value <code>x</code>, a prime
92 * modulus <code>p</code>, a base generator <code>g</code>, and a
93 * private-value length <code>l</code>.
94 *
95 * @param x the private value
96 * @param p the prime modulus
97 * @param g the base generator
98 * @param l the private-value length
99 */
100 DHPrivateKey(BigInteger x, BigInteger p, BigInteger g, int l) {
101 this.x = x;
102 this.p = p;
103 this.g = g;
104 this.l = l;
105 try {
106 this.key = new DerValue(DerValue.tag_Integer,
107 this.x.toByteArray()).toByteArray();
108 this.encodedKey = getEncoded();
109 } catch (IOException e) {
110 throw new ProviderException("Cannot produce ASN.1 encoding", e);
111 }
112 }
113
114 /**
115 * Make a DH private key from its DER encoding (PKCS #8).
116 *
117 * @param encodedKey the encoded key
118 *
119 * @exception InvalidKeyException if the encoded key does not represent
120 * a Diffie-Hellman private key
121 */
122 DHPrivateKey(byte[] encodedKey) throws InvalidKeyException {
123 InputStream inStream = new ByteArrayInputStream(encodedKey);
124 try {
125 DerValue val = new DerValue(inStream);
126 if (val.tag != DerValue.tag_Sequence) {
127 throw new InvalidKeyException ("Key not a SEQUENCE");
128 }
129
130 //
131 // version
132 //
133 BigInteger parsedVersion = val.data.getBigInteger();
134 if (!parsedVersion.equals(PKCS8_VERSION)) {
135 throw new IOException("version mismatch: (supported: " +
136 PKCS8_VERSION + ", parsed: " +
137 parsedVersion);
138 }
139
140 //
141 // privateKeyAlgorithm
142 //
143 DerValue algid = val.data.getDerValue();
144 if (algid.tag != DerValue.tag_Sequence) {
145 throw new InvalidKeyException("AlgId is not a SEQUENCE");
146 }
147 DerInputStream derInStream = algid.toDerInputStream();
148 ObjectIdentifier oid = derInStream.getOID();
149 if (oid == null) {
150 throw new InvalidKeyException("Null OID");
151 }
152 if (derInStream.available() == 0) {
153 throw new InvalidKeyException("Parameters missing");
154 }
155 // parse the parameters
156 DerValue params = derInStream.getDerValue();
157 if (params.tag == DerValue.tag_Null) {
158 throw new InvalidKeyException("Null parameters");
159 }
160 if (params.tag != DerValue.tag_Sequence) {
161 throw new InvalidKeyException("Parameters not a SEQUENCE");
162 }
163 params.data.reset();
164 this.p = params.data.getBigInteger();
165 this.g = params.data.getBigInteger();
166 // Private-value length is OPTIONAL
167 if (params.data.available() != 0) {
168 this.l = params.data.getInteger();
169 }
170 if (params.data.available() != 0) {
171 throw new InvalidKeyException("Extra parameter data");
172 }
173
174 //
175 // privateKey
176 //
177 this.key = val.data.getOctetString();
178 parseKeyBits();
179
180 this.encodedKey = encodedKey.clone();
181 } catch (IOException | NumberFormatException e) {
182 throw new InvalidKeyException("Error parsing key encoding", e);
183 }
184 }
185
186 /**
187 * Returns the encoding format of this key: "PKCS#8"
188 */
189 public String getFormat() {
190 return "PKCS#8";
191 }
192
193 /**
194 * Returns the name of the algorithm associated with this key: "DH"
195 */
196 public String getAlgorithm() {
197 return "DH";
198 }
199
200 /**
201 * Get the encoding of the key.
202 */
203 public synchronized byte[] getEncoded() {
204 if (this.encodedKey == null) {
205 try {
206 DerOutputStream tmp = new DerOutputStream();
207
208 //
209 // version
210 //
211 tmp.putInteger(PKCS8_VERSION);
212
213 //
214 // privateKeyAlgorithm
215 //
216 DerOutputStream algid = new DerOutputStream();
217
218 // store OID
219 algid.putOID(DHPublicKey.DH_OID);
220 // encode parameters
221 DerOutputStream params = new DerOutputStream();
222 params.putInteger(this.p);
223 params.putInteger(this.g);
224 if (this.l != 0) {
225 params.putInteger(this.l);
226 }
227 // wrap parameters into SEQUENCE
228 DerValue paramSequence = new DerValue(DerValue.tag_Sequence,
229 params.toByteArray());
230 // store parameter SEQUENCE in algid
231 algid.putDerValue(paramSequence);
232 // wrap algid into SEQUENCE
233 tmp.write(DerValue.tag_Sequence, algid);
234
235 // privateKey
236 tmp.putOctetString(this.key);
237
238 // make it a SEQUENCE
239 DerOutputStream derKey = new DerOutputStream();
240 derKey.write(DerValue.tag_Sequence, tmp);
241 this.encodedKey = derKey.toByteArray();
242 } catch (IOException e) {
243 return null;
244 }
245 }
246 return this.encodedKey.clone();
247 }
248
249 /**
250 * Returns the private value, <code>x</code>.
251 *
252 * @return the private value, <code>x</code>
253 */
254 public BigInteger getX() {
255 return this.x;
256 }
257
258 /**
259 * Returns the key parameters.
260 *
261 * @return the key parameters
262 */
263 public DHParameterSpec getParams() {
264 if (this.l != 0) {
265 return new DHParameterSpec(this.p, this.g, this.l);
266 } else {
267 return new DHParameterSpec(this.p, this.g);
268 }
269 }
270
271 private void parseKeyBits() throws InvalidKeyException {
272 try {
273 DerInputStream in = new DerInputStream(this.key);
274 this.x = in.getBigInteger();
275 } catch (IOException e) {
276 InvalidKeyException ike = new InvalidKeyException(
277 "Error parsing key encoding: " + e.getMessage());
278 ike.initCause(e);
279 throw ike;
280 }
281 }
282
283 /**
284 * Calculates a hash code value for the object.
285 * Objects that are equal will also have the same hashcode.
286 */
287 public int hashCode() {
288 return Objects.hash(x, p, g);
289 }
290
291 public boolean equals(Object obj) {
292 if (this == obj) return true;
293
294 if (!(obj instanceof javax.crypto.interfaces.DHPrivateKey)) {
295 return false;
296 }
297 javax.crypto.interfaces.DHPrivateKey other =
298 (javax.crypto.interfaces.DHPrivateKey) obj;
299 DHParameterSpec otherParams = other.getParams();
300 return ((this.x.compareTo(other.getX()) == 0) &&
301 (this.p.compareTo(otherParams.getP()) == 0) &&
302 (this.g.compareTo(otherParams.getG()) == 0));
303 }
304
305 /**
306 * Replace the DH private key to be serialized.
307 *
308 * @return the standard KeyRep object to be serialized
309 *
310 * @throws java.io.ObjectStreamException if a new object representing
311 * this DH private key could not be created
312 */
313 @java.io.Serial
314 private Object writeReplace() throws java.io.ObjectStreamException {
315 return new KeyRep(KeyRep.Type.PRIVATE,
316 getAlgorithm(),
317 getFormat(),
318 getEncoded());
319 }
320 }