1 /*
2 * Copyright (c) 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 package sun.security.provider;
27
28 import sun.security.util.HexDumpEncoder;
29
30 import java.util.Arrays;
31 import java.util.Locale;
32
33 public abstract class AbstractHashDrbg extends AbstractDrbg {
34
35 private static final long serialVersionUID = 9L;
36
37 protected int outLen;
38 protected int seedLen;
39
40 private static int alg2strength(String algorithm) {
41 switch (algorithm.toUpperCase(Locale.ROOT)) {
42 case "SHA-1":
43 return 128;
44 case "SHA-224":
45 case "SHA-512/224":
46 return 192;
47 case "SHA-256":
48 case "SHA-512/256":
49 case "SHA-384":
50 case "SHA-512":
51 return 256;
52 default:
53 throw new IllegalArgumentException(algorithm +
54 " not supported in Hash_DBRG");
55 }
56 }
57
58 protected void chooseAlgorithmAndStrength() {
59 if (requestedAlgorithm != null) {
60 algorithm = requestedAlgorithm.toUpperCase(Locale.ROOT);
61 int supportedStrength = alg2strength(algorithm);
62 if (requestedStrength >= 0) {
63 int tryStrength = getStandardStrength(requestedStrength);
64 if (tryStrength > supportedStrength) {
65 throw new IllegalArgumentException(
66 algorithm + " does not support strength " + requestedStrength);
67 }
68 this.strength = tryStrength;
69 } else {
70 this.strength = defaultStrength > supportedStrength?
71 supportedStrength: defaultStrength;
72 }
73 } else {
74 int tryStrength =
75 requestedStrength<0? defaultStrength: requestedStrength;
76 tryStrength = getStandardStrength(tryStrength);
77 // The default algorithm which is enough for all strengths.
78 // Also described in comments of the "drbg" security property.
79 algorithm = "SHA-256";
80 this.strength = tryStrength;
81 }
82 switch (algorithm.toUpperCase(Locale.ROOT)) {
83 case "SHA-1":
84 this.seedLen = 440/8;
85 this.outLen = 160/8;
86 break;
87 case "SHA-224":
88 case "SHA-512/224":
89 this.seedLen = 440/8;
90 this.outLen = 224/8;
91 break;
92 case "SHA-256":
93 case "SHA-512/256":
94 this.seedLen = 440/8;
95 this.outLen = 256/8;
96 break;
97 case "SHA-384":
98 this.seedLen = 888/8;
99 this.outLen = 384/8;
100 break;
101 case "SHA-512":
102 this.seedLen = 888/8;
103 this.outLen = 512/8;
104 break;
105 default:
106 throw new IllegalArgumentException(algorithm +
107 " not supported in Hash_DBRG");
108 }
109 this.minLength = this.strength/8;
110 }
111
112 @Override
113 public void instantiateAlgorithm(byte[] entropy) {
114 byte[] seed = Arrays.copyOf(entropy, entropy.length + nonce.length +
115 (ps == null? 0: ps.length));
116 System.arraycopy(nonce, 0, seed, entropy.length, nonce.length);
117 if (ps != null) {
118 System.arraycopy(ps, 0, seed, entropy.length + nonce.length,
119 ps.length);
120 }
121 hashReseedInternal(seed);
122 }
123
124 @Override
125 protected void reseedAlgorithm(
126 byte[] ei,
127 byte[] additionalInput) {
128 if (debug != null) {
129 debug.println("reseedAlgorithm");
130 debug.println(new HexDumpEncoder().encodeBuffer(ei));
131 if (additionalInput != null) {
132 debug.println(new HexDumpEncoder().encodeBuffer(additionalInput));
133 }
134 }
135 if (additionalInput != null) {
136 ei = Arrays.copyOf(ei, ei.length + additionalInput.length);
137 System.arraycopy(additionalInput, 0, ei,
138 ei.length - additionalInput.length, additionalInput.length);
139 }
140 hashReseedInternal(ei);
141 }
142
143 protected abstract void hashReseedInternal(byte[] seed);
144 }