-
Notifications
You must be signed in to change notification settings - Fork 5.4k
/
EphemeralKeyManager.java
139 lines (120 loc) · 4.17 KB
/
EphemeralKeyManager.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/*
* Copyright (c) 2002, 2021, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.security.ssl;
import java.security.*;
import java.util.concurrent.locks.ReentrantLock;
/**
* The "KeyManager" for ephemeral RSA keys. Ephemeral DH and ECDH keys
* are handled by the DHCrypt and ECDHCrypt classes, respectively.
*
* @author Andreas Sterbenz
*/
final class EphemeralKeyManager {
// indices for the keys array below
private static final int INDEX_RSA512 = 0;
private static final int INDEX_RSA1024 = 1;
/*
* Current cached RSA KeyPairs. Elements are never null.
* Indexed via the constants above.
*/
private final EphemeralKeyPair[] keys = new EphemeralKeyPair[] {
new EphemeralKeyPair(null),
new EphemeralKeyPair(null),
};
private final ReentrantLock cachedKeysLock = new ReentrantLock();
EphemeralKeyManager() {
// empty
}
/*
* Get a temporary RSA KeyPair.
*/
KeyPair getRSAKeyPair(boolean export, SecureRandom random) {
int length, index;
if (export) {
length = 512;
index = INDEX_RSA512;
} else {
length = 1024;
index = INDEX_RSA1024;
}
KeyPair kp = keys[index].getKeyPair();
if (kp != null) {
return kp;
}
cachedKeysLock.lock();
try {
// double check
kp = keys[index].getKeyPair();
if (kp != null) {
return kp;
}
try {
KeyPairGenerator kgen = KeyPairGenerator.getInstance("RSA");
kgen.initialize(length, random);
keys[index] = new EphemeralKeyPair(kgen.genKeyPair());
kp = keys[index].getKeyPair();
} catch (Exception e) {
// ignore
}
} finally {
cachedKeysLock.unlock();
}
return kp;
}
/**
* Inner class to handle storage of ephemeral KeyPairs.
*/
private static class EphemeralKeyPair {
// maximum number of times a KeyPair is used
private static final int MAX_USE = 200;
// maximum time interval in which the keypair is used (1 hour in ms)
private static final long USE_INTERVAL = 3600*1000;
private KeyPair keyPair;
private int uses;
private final long expirationTime;
private EphemeralKeyPair(KeyPair keyPair) {
this.keyPair = keyPair;
expirationTime = System.currentTimeMillis() + USE_INTERVAL;
}
/*
* Check if the KeyPair can still be used.
*/
private boolean isValid() {
return (keyPair != null) && (uses < MAX_USE)
&& (System.currentTimeMillis() < expirationTime);
}
/*
* Return the KeyPair or null if it is invalid.
*/
private KeyPair getKeyPair() {
if (!isValid()) {
keyPair = null;
return null;
}
uses++;
return keyPair;
}
}
}