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 * @exception InvalidKeyException if the key cannot be encoded
101 */
102 DHPrivateKey(BigInteger x, BigInteger p, BigInteger g, int l) {
103 this.x = x;
104 this.p = p;
105 this.g = g;
106 this.l = l;
107 try {
108 this.key = new DerValue(DerValue.tag_Integer,
109 this.x.toByteArray()).toByteArray();
110 this.encodedKey = getEncoded();
111 } catch (IOException e) {
112 throw new ProviderException("Cannot produce ASN.1 encoding", e);
113 }
114 }
115
116 /**
117 * Make a DH private key from its DER encoding (PKCS #8).
118 *
119 * @param encodedKey the encoded key
120 *
121 * @exception InvalidKeyException if the encoded key does not represent
122 * a Diffie-Hellman private key
123 */
124 DHPrivateKey(byte[] encodedKey) throws InvalidKeyException {
125 InputStream inStream = new ByteArrayInputStream(encodedKey);
126 try {
127 DerValue val = new DerValue(inStream);
128 if (val.tag != DerValue.tag_Sequence) {
129 throw new InvalidKeyException ("Key not a SEQUENCE");
130 }
131
132 //
133 // version
134 //
135 BigInteger parsedVersion = val.data.getBigInteger();
136 if (!parsedVersion.equals(PKCS8_VERSION)) {
137 throw new IOException("version mismatch: (supported: " +
138 PKCS8_VERSION + ", parsed: " +
139 parsedVersion);
140 }
141
142 //
143 // privateKeyAlgorithm
144 //
145 DerValue algid = val.data.getDerValue();
146 if (algid.tag != DerValue.tag_Sequence) {
147 throw new InvalidKeyException("AlgId is not a SEQUENCE");
148 }
149 DerInputStream derInStream = algid.toDerInputStream();
150 ObjectIdentifier oid = derInStream.getOID();
151 if (oid == null) {
152 throw new InvalidKeyException("Null OID");
153 }
154 if (derInStream.available() == 0) {
155 throw new InvalidKeyException("Parameters missing");
156 }
157 // parse the parameters
158 DerValue params = derInStream.getDerValue();
159 if (params.tag == DerValue.tag_Null) {
160 throw new InvalidKeyException("Null parameters");
161 }
162 if (params.tag != DerValue.tag_Sequence) {
163 throw new InvalidKeyException("Parameters not a SEQUENCE");
164 }
165 params.data.reset();
166 this.p = params.data.getBigInteger();
167 this.g = params.data.getBigInteger();
168 // Private-value length is OPTIONAL
169 if (params.data.available() != 0) {
170 this.l = params.data.getInteger();
171 }
172 if (params.data.available() != 0) {
173 throw new InvalidKeyException("Extra parameter data");
174 }
175
176 //
177 // privateKey
178 //
179 this.key = val.data.getOctetString();
180 parseKeyBits();
181
182 this.encodedKey = encodedKey.clone();
183 } catch (IOException | NumberFormatException e) {
184 throw new InvalidKeyException("Error parsing key encoding", e);
185 }
186 }
187
188 /**
189 * Returns the encoding format of this key: "PKCS#8"
190 */
191 public String getFormat() {
192 return "PKCS#8";
193 }
194
195 /**
196 * Returns the name of the algorithm associated with this key: "DH"
197 */
198 public String getAlgorithm() {
199 return "DH";
200 }
201
202 /**
203 * Get the encoding of the key.
204 */
205 public synchronized byte[] getEncoded() {
206 if (this.encodedKey == null) {
207 try {
208 DerOutputStream tmp = new DerOutputStream();
209
210 //
211 // version
212 //
213 tmp.putInteger(PKCS8_VERSION);
214
215 //
216 // privateKeyAlgorithm
217 //
218 DerOutputStream algid = new DerOutputStream();
219
220 // store OID
221 algid.putOID(DHPublicKey.DH_OID);
222 // encode parameters
223 DerOutputStream params = new DerOutputStream();
224 params.putInteger(this.p);
225 params.putInteger(this.g);
226 if (this.l != 0) {
227 params.putInteger(this.l);
228 }
229 // wrap parameters into SEQUENCE
230 DerValue paramSequence = new DerValue(DerValue.tag_Sequence,
231 params.toByteArray());
232 // store parameter SEQUENCE in algid
233 algid.putDerValue(paramSequence);
234 // wrap algid into SEQUENCE
235 tmp.write(DerValue.tag_Sequence, algid);
236
237 // privateKey
238 tmp.putOctetString(this.key);
239
240 // make it a SEQUENCE
241 DerOutputStream derKey = new DerOutputStream();
242 derKey.write(DerValue.tag_Sequence, tmp);
243 this.encodedKey = derKey.toByteArray();
244 } catch (IOException e) {
245 return null;
246 }
247 }
248 return this.encodedKey.clone();
249 }
250
251 /**
252 * Returns the private value, <code>x</code>.
253 *
254 * @return the private value, <code>x</code>
255 */
256 public BigInteger getX() {
257 return this.x;
258 }
259
260 /**
261 * Returns the key parameters.
262 *
263 * @return the key parameters
264 */
265 public DHParameterSpec getParams() {
266 if (this.l != 0) {
267 return new DHParameterSpec(this.p, this.g, this.l);
268 } else {
269 return new DHParameterSpec(this.p, this.g);
270 }
271 }
272
273 private void parseKeyBits() throws InvalidKeyException {
274 try {
275 DerInputStream in = new DerInputStream(this.key);
276 this.x = in.getBigInteger();
277 } catch (IOException e) {
278 InvalidKeyException ike = new InvalidKeyException(
279 "Error parsing key encoding: " + e.getMessage());
280 ike.initCause(e);
281 throw ike;
282 }
283 }
284
285 /**
286 * Calculates a hash code value for the object.
287 * Objects that are equal will also have the same hashcode.
288 */
289 public int hashCode() {
290 return Objects.hash(x, p, g);
291 }
292
293 public boolean equals(Object obj) {
294 if (this == obj) return true;
295
296 if (!(obj instanceof javax.crypto.interfaces.DHPrivateKey)) {
297 return false;
298 }
299 javax.crypto.interfaces.DHPrivateKey other =
300 (javax.crypto.interfaces.DHPrivateKey) obj;
301 DHParameterSpec otherParams = other.getParams();
302 return ((this.x.compareTo(other.getX()) == 0) &&
303 (this.p.compareTo(otherParams.getP()) == 0) &&
304 (this.g.compareTo(otherParams.getG()) == 0));
305 }
306
307 /**
308 * Replace the DH private key to be serialized.
309 *
310 * @return the standard KeyRep object to be serialized
311 *
312 * @throws java.io.ObjectStreamException if a new object representing
313 * this DH private key could not be created
314 */
315 @java.io.Serial
316 private Object writeReplace() throws java.io.ObjectStreamException {
317 return new KeyRep(KeyRep.Type.PRIVATE,
318 getAlgorithm(),
319 getFormat(),
320 getEncoded());
321 }
322 }