1/*
2 * Copyright (c) 1996, 2016, 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
27package sun.security.ssl;
28
29import java.util.Map;
30import java.util.HashMap;
31import java.util.Collections;
32import java.util.regex.Pattern;
33import java.util.regex.Matcher;
34import java.math.BigInteger;
35import java.security.*;
36import java.io.IOException;
37import javax.net.ssl.SSLHandshakeException;
38import javax.crypto.SecretKey;
39import javax.crypto.KeyAgreement;
40import javax.crypto.interfaces.DHPublicKey;
41import javax.crypto.spec.*;
42import java.util.EnumSet;
43
44import sun.security.util.KeyUtil;
45
46/**
47 * This class implements the Diffie-Hellman key exchange algorithm.
48 * D-H means combining your private key with your partners public key to
49 * generate a number. The peer does the same with its private key and our
50 * public key. Through the magic of Diffie-Hellman we both come up with the
51 * same number. This number is secret (discounting MITM attacks) and hence
52 * called the shared secret. It has the same length as the modulus, e.g. 512
53 * or 1024 bit. Man-in-the-middle attacks are typically countered by an
54 * independent authentication step using certificates (RSA, DSA, etc.).
55 *
56 * The thing to note is that the shared secret is constant for two partners
57 * with constant private keys. This is often not what we want, which is why
58 * it is generally a good idea to create a new private key for each session.
59 * Generating a private key involves one modular exponentiation assuming
60 * suitable D-H parameters are available.
61 *
62 * General usage of this class (TLS DHE case):
63 *  . if we are server, call DHCrypt(keyLength,random). This generates
64 *    an ephemeral keypair of the request length.
65 *  . if we are client, call DHCrypt(modulus, base, random). This
66 *    generates an ephemeral keypair using the parameters specified by
67 *    the server.
68 *  . send parameters and public value to remote peer
69 *  . receive peers ephemeral public key
70 *  . call getAgreedSecret() to calculate the shared secret
71 *
72 * In TLS the server chooses the parameter values itself, the client must use
73 * those sent to it by the server.
74 *
75 * The use of ephemeral keys as described above also achieves what is called
76 * "forward secrecy". This means that even if the authentication keys are
77 * broken at a later date, the shared secret remains secure. The session is
78 * compromised only if the authentication keys are already broken at the
79 * time the key exchange takes place and an active MITM attack is used.
80 * This is in contrast to straightforward encrypting RSA key exchanges.
81 *
82 * @author David Brownell
83 */
84final class DHCrypt {
85
86    // group parameters (prime modulus and generator)
87    private BigInteger modulus;                 // P (aka N)
88    private BigInteger base;                    // G (aka alpha)
89
90    // our private key (including private component x)
91    private PrivateKey privateKey;
92
93    // public component of our key, X = (g ^ x) mod p
94    private BigInteger publicValue;             // X (aka y)
95
96    // the times to recove from failure if public key validation
97    private static int MAX_FAILOVER_TIMES = 2;
98
99    /**
100     * Generate a Diffie-Hellman keypair of the specified size.
101     */
102    DHCrypt(int keyLength, SecureRandom random) {
103        this(keyLength,
104                ParametersHolder.definedParams.get(keyLength), random);
105    }
106
107    /**
108     * Generate a Diffie-Hellman keypair using the specified parameters.
109     *
110     * @param modulus the Diffie-Hellman modulus P
111     * @param base the Diffie-Hellman base G
112     */
113    DHCrypt(BigInteger modulus, BigInteger base, SecureRandom random) {
114        this(modulus.bitLength(),
115                new DHParameterSpec(modulus, base), random);
116    }
117
118    /**
119     * Generate a Diffie-Hellman keypair using the specified size and
120     * parameters.
121     */
122    private DHCrypt(int keyLength,
123            DHParameterSpec params, SecureRandom random) {
124
125        try {
126            KeyPairGenerator kpg = JsseJce.getKeyPairGenerator("DiffieHellman");
127            if (params != null) {
128                kpg.initialize(params, random);
129            } else {
130                kpg.initialize(keyLength, random);
131            }
132
133            DHPublicKeySpec spec = generateDHPublicKeySpec(kpg);
134            if (spec == null) {
135                throw new RuntimeException("Could not generate DH keypair");
136            }
137
138            publicValue = spec.getY();
139            modulus = spec.getP();
140            base = spec.getG();
141        } catch (GeneralSecurityException e) {
142            throw new RuntimeException("Could not generate DH keypair", e);
143        }
144    }
145
146    static DHPublicKeySpec getDHPublicKeySpec(PublicKey key) {
147        if (key instanceof DHPublicKey) {
148            DHPublicKey dhKey = (DHPublicKey)key;
149            DHParameterSpec params = dhKey.getParams();
150            return new DHPublicKeySpec(dhKey.getY(),
151                                    params.getP(), params.getG());
152        }
153        try {
154            KeyFactory factory = JsseJce.getKeyFactory("DiffieHellman");
155            return factory.getKeySpec(key, DHPublicKeySpec.class);
156        } catch (Exception e) {
157            throw new RuntimeException(e);
158        }
159    }
160
161
162    /** Returns the Diffie-Hellman modulus. */
163    BigInteger getModulus() {
164        return modulus;
165    }
166
167    /** Returns the Diffie-Hellman base (generator).  */
168    BigInteger getBase() {
169        return base;
170    }
171
172    /**
173     * Gets the public key of this end of the key exchange.
174     */
175    BigInteger getPublicKey() {
176        return publicValue;
177    }
178
179    /**
180     * Get the secret data that has been agreed on through Diffie-Hellman
181     * key agreement protocol.  Note that in the two party protocol, if
182     * the peer keys are already known, no other data needs to be sent in
183     * order to agree on a secret.  That is, a secured message may be
184     * sent without any mandatory round-trip overheads.
185     *
186     * <P>It is illegal to call this member function if the private key
187     * has not been set (or generated).
188     *
189     * @param  peerPublicKey the peer's public key.
190     * @param  keyIsValidated whether the {@code peerPublicKey} has beed
191     *         validated
192     * @return the secret, which is an unsigned big-endian integer
193     *         the same size as the Diffie-Hellman modulus.
194     */
195    SecretKey getAgreedSecret(BigInteger peerPublicValue,
196            boolean keyIsValidated) throws SSLHandshakeException {
197        try {
198            KeyFactory kf = JsseJce.getKeyFactory("DiffieHellman");
199            DHPublicKeySpec spec =
200                        new DHPublicKeySpec(peerPublicValue, modulus, base);
201            PublicKey publicKey = kf.generatePublic(spec);
202            KeyAgreement ka = JsseJce.getKeyAgreement("DiffieHellman");
203
204            // validate the Diffie-Hellman public key
205            if (!keyIsValidated &&
206                    !KeyUtil.isOracleJCEProvider(ka.getProvider().getName())) {
207                try {
208                    KeyUtil.validate(spec);
209                } catch (InvalidKeyException ike) {
210                    // prefer handshake_failure alert to internal_error alert
211                    throw new SSLHandshakeException(ike.getMessage());
212                }
213            }
214
215            ka.init(privateKey);
216            ka.doPhase(publicKey, true);
217            return ka.generateSecret("TlsPremasterSecret");
218        } catch (GeneralSecurityException e) {
219            throw (SSLHandshakeException) new SSLHandshakeException(
220                "Could not generate secret").initCause(e);
221        }
222    }
223
224    // Check constraints of the specified DH public key.
225    void checkConstraints(AlgorithmConstraints constraints,
226            BigInteger peerPublicValue) throws SSLHandshakeException {
227
228        try {
229            KeyFactory kf = JsseJce.getKeyFactory("DiffieHellman");
230            DHPublicKeySpec spec =
231                        new DHPublicKeySpec(peerPublicValue, modulus, base);
232            DHPublicKey publicKey = (DHPublicKey)kf.generatePublic(spec);
233
234            // check constraints of DHPublicKey
235            if (!constraints.permits(
236                    EnumSet.of(CryptoPrimitive.KEY_AGREEMENT), publicKey)) {
237                throw new SSLHandshakeException(
238                    "DHPublicKey does not comply to algorithm constraints");
239            }
240        } catch (GeneralSecurityException gse) {
241            throw (SSLHandshakeException) new SSLHandshakeException(
242                    "Could not generate DHPublicKey").initCause(gse);
243        }
244    }
245
246    // Generate and validate DHPublicKeySpec
247    private DHPublicKeySpec generateDHPublicKeySpec(KeyPairGenerator kpg)
248            throws GeneralSecurityException {
249
250        boolean doExtraValiadtion =
251                    (!KeyUtil.isOracleJCEProvider(kpg.getProvider().getName()));
252        for (int i = 0; i <= MAX_FAILOVER_TIMES; i++) {
253            KeyPair kp = kpg.generateKeyPair();
254            privateKey = kp.getPrivate();
255            DHPublicKeySpec spec = getDHPublicKeySpec(kp.getPublic());
256
257            // validate the Diffie-Hellman public key
258            if (doExtraValiadtion) {
259                try {
260                    KeyUtil.validate(spec);
261                } catch (InvalidKeyException ivke) {
262                    if (i == MAX_FAILOVER_TIMES) {
263                        throw ivke;
264                    }
265                    // otherwise, ignore the exception and try the next one
266                    continue;
267                }
268            }
269
270            return spec;
271        }
272
273        return null;
274    }
275
276    // lazy initialization holder class idiom for static default parameters
277    //
278    // See Effective Java Second Edition: Item 71.
279    private static class ParametersHolder {
280        private final static boolean debugIsOn =
281                (Debug.getInstance("ssl") != null) && Debug.isOn("sslctx");
282
283        //
284        // Default DH ephemeral parameters
285        //
286        private static final BigInteger p512 = new BigInteger(   // generated
287                "D87780E15FF50B4ABBE89870188B049406B5BEA98AB23A02" +
288                "41D88EA75B7755E669C08093D3F0CA7FC3A5A25CF067DCB9" +
289                "A43DD89D1D90921C6328884461E0B6D3", 16);
290        private static final BigInteger p768 = new BigInteger(   // RFC 2409
291                "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1" +
292                "29024E088A67CC74020BBEA63B139B22514A08798E3404DD" +
293                "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245" +
294                "E485B576625E7EC6F44C42E9A63A3620FFFFFFFFFFFFFFFF", 16);
295
296        private static final BigInteger p1024 = new BigInteger(  // RFC 2409
297                "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1" +
298                "29024E088A67CC74020BBEA63B139B22514A08798E3404DD" +
299                "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245" +
300                "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED" +
301                "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381" +
302                "FFFFFFFFFFFFFFFF", 16);
303        private static final BigInteger p1536 = new BigInteger(  // RFC 3526
304                "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1" +
305                "29024E088A67CC74020BBEA63B139B22514A08798E3404DD" +
306                "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245" +
307                "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED" +
308                "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D" +
309                "C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F" +
310                "83655D23DCA3AD961C62F356208552BB9ED529077096966D" +
311                "670C354E4ABC9804F1746C08CA237327FFFFFFFFFFFFFFFF", 16);
312        private static final BigInteger p2048 = new BigInteger(  // TLS FFDHE
313                "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" +
314                "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" +
315                "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" +
316                "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" +
317                "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" +
318                "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" +
319                "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" +
320                "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" +
321                "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" +
322                "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" +
323                "886B423861285C97FFFFFFFFFFFFFFFF", 16);
324        private static final BigInteger p3072 = new BigInteger(  // TLS FFDHE
325                "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" +
326                "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" +
327                "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" +
328                "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" +
329                "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" +
330                "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" +
331                "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" +
332                "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" +
333                "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" +
334                "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" +
335                "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" +
336                "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" +
337                "AEFE130985139270B4130C93BC437944F4FD4452E2D74DD3" +
338                "64F2E21E71F54BFF5CAE82AB9C9DF69EE86D2BC522363A0D" +
339                "ABC521979B0DEADA1DBF9A42D5C4484E0ABCD06BFA53DDEF" +
340                "3C1B20EE3FD59D7C25E41D2B66C62E37FFFFFFFFFFFFFFFF", 16);
341        private static final BigInteger p4096 = new BigInteger(  // TLS FFDHE
342                "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" +
343                "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" +
344                "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" +
345                "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" +
346                "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" +
347                "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" +
348                "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" +
349                "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" +
350                "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" +
351                "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" +
352                "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" +
353                "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" +
354                "AEFE130985139270B4130C93BC437944F4FD4452E2D74DD3" +
355                "64F2E21E71F54BFF5CAE82AB9C9DF69EE86D2BC522363A0D" +
356                "ABC521979B0DEADA1DBF9A42D5C4484E0ABCD06BFA53DDEF" +
357                "3C1B20EE3FD59D7C25E41D2B669E1EF16E6F52C3164DF4FB" +
358                "7930E9E4E58857B6AC7D5F42D69F6D187763CF1D55034004" +
359                "87F55BA57E31CC7A7135C886EFB4318AED6A1E012D9E6832" +
360                "A907600A918130C46DC778F971AD0038092999A333CB8B7A" +
361                "1A1DB93D7140003C2A4ECEA9F98D0ACC0A8291CDCEC97DCF" +
362                "8EC9B55A7F88A46B4DB5A851F44182E1C68A007E5E655F6A" +
363                "FFFFFFFFFFFFFFFF", 16);
364        private static final BigInteger p6144 = new BigInteger(  // TLS FFDHE
365                "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" +
366                "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" +
367                "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" +
368                "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" +
369                "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" +
370                "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" +
371                "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" +
372                "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" +
373                "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" +
374                "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" +
375                "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" +
376                "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" +
377                "AEFE130985139270B4130C93BC437944F4FD4452E2D74DD3" +
378                "64F2E21E71F54BFF5CAE82AB9C9DF69EE86D2BC522363A0D" +
379                "ABC521979B0DEADA1DBF9A42D5C4484E0ABCD06BFA53DDEF" +
380                "3C1B20EE3FD59D7C25E41D2B669E1EF16E6F52C3164DF4FB" +
381                "7930E9E4E58857B6AC7D5F42D69F6D187763CF1D55034004" +
382                "87F55BA57E31CC7A7135C886EFB4318AED6A1E012D9E6832" +
383                "A907600A918130C46DC778F971AD0038092999A333CB8B7A" +
384                "1A1DB93D7140003C2A4ECEA9F98D0ACC0A8291CDCEC97DCF" +
385                "8EC9B55A7F88A46B4DB5A851F44182E1C68A007E5E0DD902" +
386                "0BFD64B645036C7A4E677D2C38532A3A23BA4442CAF53EA6" +
387                "3BB454329B7624C8917BDD64B1C0FD4CB38E8C334C701C3A" +
388                "CDAD0657FCCFEC719B1F5C3E4E46041F388147FB4CFDB477" +
389                "A52471F7A9A96910B855322EDB6340D8A00EF092350511E3" +
390                "0ABEC1FFF9E3A26E7FB29F8C183023C3587E38DA0077D9B4" +
391                "763E4E4B94B2BBC194C6651E77CAF992EEAAC0232A281BF6" +
392                "B3A739C1226116820AE8DB5847A67CBEF9C9091B462D538C" +
393                "D72B03746AE77F5E62292C311562A846505DC82DB854338A" +
394                "E49F5235C95B91178CCF2DD5CACEF403EC9D1810C6272B04" +
395                "5B3B71F9DC6B80D63FDD4A8E9ADB1E6962A69526D43161C1" +
396                "A41D570D7938DAD4A40E329CD0E40E65FFFFFFFFFFFFFFFF", 16);
397        private static final BigInteger p8192 = new BigInteger(  // TLS FFDHE
398                "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" +
399                "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" +
400                "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" +
401                "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" +
402                "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" +
403                "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" +
404                "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" +
405                "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" +
406                "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" +
407                "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" +
408                "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" +
409                "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" +
410                "AEFE130985139270B4130C93BC437944F4FD4452E2D74DD3" +
411                "64F2E21E71F54BFF5CAE82AB9C9DF69EE86D2BC522363A0D" +
412                "ABC521979B0DEADA1DBF9A42D5C4484E0ABCD06BFA53DDEF" +
413                "3C1B20EE3FD59D7C25E41D2B669E1EF16E6F52C3164DF4FB" +
414                "7930E9E4E58857B6AC7D5F42D69F6D187763CF1D55034004" +
415                "87F55BA57E31CC7A7135C886EFB4318AED6A1E012D9E6832" +
416                "A907600A918130C46DC778F971AD0038092999A333CB8B7A" +
417                "1A1DB93D7140003C2A4ECEA9F98D0ACC0A8291CDCEC97DCF" +
418                "8EC9B55A7F88A46B4DB5A851F44182E1C68A007E5E0DD902" +
419                "0BFD64B645036C7A4E677D2C38532A3A23BA4442CAF53EA6" +
420                "3BB454329B7624C8917BDD64B1C0FD4CB38E8C334C701C3A" +
421                "CDAD0657FCCFEC719B1F5C3E4E46041F388147FB4CFDB477" +
422                "A52471F7A9A96910B855322EDB6340D8A00EF092350511E3" +
423                "0ABEC1FFF9E3A26E7FB29F8C183023C3587E38DA0077D9B4" +
424                "763E4E4B94B2BBC194C6651E77CAF992EEAAC0232A281BF6" +
425                "B3A739C1226116820AE8DB5847A67CBEF9C9091B462D538C" +
426                "D72B03746AE77F5E62292C311562A846505DC82DB854338A" +
427                "E49F5235C95B91178CCF2DD5CACEF403EC9D1810C6272B04" +
428                "5B3B71F9DC6B80D63FDD4A8E9ADB1E6962A69526D43161C1" +
429                "A41D570D7938DAD4A40E329CCFF46AAA36AD004CF600C838" +
430                "1E425A31D951AE64FDB23FCEC9509D43687FEB69EDD1CC5E" +
431                "0B8CC3BDF64B10EF86B63142A3AB8829555B2F747C932665" +
432                "CB2C0F1CC01BD70229388839D2AF05E454504AC78B758282" +
433                "2846C0BA35C35F5C59160CC046FD8251541FC68C9C86B022" +
434                "BB7099876A460E7451A8A93109703FEE1C217E6C3826E52C" +
435                "51AA691E0E423CFC99E9E31650C1217B624816CDAD9A95F9" +
436                "D5B8019488D9C0A0A1FE3075A577E23183F81D4A3F2FA457" +
437                "1EFC8CE0BA8A4FE8B6855DFE72B0A66EDED2FBABFBE58A30" +
438                "FAFABE1C5D71A87E2F741EF8C1FE86FEA6BBFDE530677F0D" +
439                "97D11D49F7A8443D0822E506A9F4614E011E2A94838FF88C" +
440                "D68C8BB7C5C6424CFFFFFFFFFFFFFFFF", 16);
441
442        private static final BigInteger[] supportedPrimes = {
443                p512, p768, p1024, p1536, p2048, p3072, p4096, p6144, p8192};
444
445        // a measure of the uncertainty that prime modulus p is not a prime
446        //
447        // see BigInteger.isProbablePrime(int certainty)
448        private final static int PRIME_CERTAINTY = 120;
449
450        // the known security property, jdk.tls.server.defaultDHEParameters
451        private final static String PROPERTY_NAME =
452                "jdk.tls.server.defaultDHEParameters";
453
454        private static final Pattern spacesPattern = Pattern.compile("\\s+");
455
456        private final static Pattern syntaxPattern = Pattern.compile(
457                "(\\{[0-9A-Fa-f]+,[0-9A-Fa-f]+\\})" +
458                "(,\\{[0-9A-Fa-f]+,[0-9A-Fa-f]+\\})*");
459
460        private static final Pattern paramsPattern = Pattern.compile(
461                "\\{([0-9A-Fa-f]+),([0-9A-Fa-f]+)\\}");
462
463        // cache of predefined default DH ephemeral parameters
464        private final static Map<Integer,DHParameterSpec> definedParams;
465
466        static {
467            String property = AccessController.doPrivileged(
468                new PrivilegedAction<String>() {
469                    public String run() {
470                        return Security.getProperty(PROPERTY_NAME);
471                    }
472                });
473
474            if (property != null && !property.isEmpty()) {
475                // remove double quote marks from beginning/end of the property
476                if (property.length() >= 2 && property.charAt(0) == '"' &&
477                        property.charAt(property.length() - 1) == '"') {
478                    property = property.substring(1, property.length() - 1);
479                }
480
481                property = property.trim();
482            }
483
484            if (property != null && !property.isEmpty()) {
485                Matcher spacesMatcher = spacesPattern.matcher(property);
486                property = spacesMatcher.replaceAll("");
487
488                if (debugIsOn) {
489                    System.out.println("The Security Property " +
490                            PROPERTY_NAME + ": " + property);
491                }
492            }
493
494            Map<Integer,DHParameterSpec> defaultParams = new HashMap<>();
495            if (property != null && !property.isEmpty()) {
496                Matcher syntaxMatcher = syntaxPattern.matcher(property);
497                if (syntaxMatcher.matches()) {
498                    Matcher paramsFinder = paramsPattern.matcher(property);
499                    while(paramsFinder.find()) {
500                        String primeModulus = paramsFinder.group(1);
501                        BigInteger p = new BigInteger(primeModulus, 16);
502                        if (!p.isProbablePrime(PRIME_CERTAINTY)) {
503                            if (debugIsOn) {
504                                System.out.println(
505                                    "Prime modulus p in Security Property, " +
506                                    PROPERTY_NAME + ", is not a prime: " +
507                                    primeModulus);
508                            }
509
510                            continue;
511                        }
512
513                        String baseGenerator = paramsFinder.group(2);
514                        BigInteger g = new BigInteger(baseGenerator, 16);
515
516                        DHParameterSpec spec = new DHParameterSpec(p, g);
517                        int primeLen = p.bitLength();
518                        defaultParams.put(primeLen, spec);
519                    }
520                } else if (debugIsOn) {
521                    System.out.println("Invalid Security Property, " +
522                            PROPERTY_NAME + ", definition");
523                }
524            }
525
526            for (BigInteger p : supportedPrimes) {
527                int primeLen = p.bitLength();
528                defaultParams.putIfAbsent(primeLen,
529                        new DHParameterSpec(p, BigInteger.TWO));
530            }
531
532            definedParams =
533                    Collections.<Integer,DHParameterSpec>unmodifiableMap(
534                                                                defaultParams);
535        }
536    }
537}
538