1 /*
2 * Copyright (c) 2006, 2013, 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.util;
27
28 import java.io.IOException;
29
30 import java.math.BigInteger;
31
32 import java.security.*;
33
34 import java.security.interfaces.*;
35
36 import java.security.spec.*;
37
38 import java.util.Arrays;
39
40 import sun.security.x509.X509Key;
41
42 public class ECUtil {
43
44 // Used by SunPKCS11 and SunJSSE.
45 public static ECPoint decodePoint(byte[] data, EllipticCurve curve)
46 throws IOException {
47 if ((data.length == 0) || (data[0] != 4)) {
48 throw new IOException("Only uncompressed point format supported");
49 }
50 // Per ANSI X9.62, an encoded point is a 1 byte type followed by
51 // ceiling(log base 2 field-size / 8) bytes of x and the same of y.
52 int n = (data.length - 1) / 2;
53 if (n != ((curve.getField().getFieldSize() + 7 ) >> 3)) {
54 throw new IOException("Point does not match field size");
55 }
56
57 byte[] xb = Arrays.copyOfRange(data, 1, 1 + n);
58 byte[] yb = Arrays.copyOfRange(data, n + 1, n + 1 + n);
59
60 return new ECPoint(new BigInteger(1, xb), new BigInteger(1, yb));
61 }
62
63 // Used by SunPKCS11 and SunJSSE.
64 public static byte[] encodePoint(ECPoint point, EllipticCurve curve) {
65 // get field size in bytes (rounding up)
66 int n = (curve.getField().getFieldSize() + 7) >> 3;
67 byte[] xb = trimZeroes(point.getAffineX().toByteArray());
68 byte[] yb = trimZeroes(point.getAffineY().toByteArray());
69 if ((xb.length > n) || (yb.length > n)) {
70 throw new RuntimeException
71 ("Point coordinates do not match field size");
72 }
73 byte[] b = new byte[1 + (n << 1)];
74 b[0] = 4; // uncompressed
75 System.arraycopy(xb, 0, b, n - xb.length + 1, xb.length);
76 System.arraycopy(yb, 0, b, b.length - yb.length, yb.length);
77 return b;
78 }
79
80 public static byte[] trimZeroes(byte[] b) {
81 int i = 0;
82 while ((i < b.length - 1) && (b[i] == 0)) {
83 i++;
84 }
85 if (i == 0) {
86 return b;
87 }
88
89 return Arrays.copyOfRange(b, i, b.length);
90 }
91
92 private static KeyFactory getKeyFactory() {
93 try {
94 return KeyFactory.getInstance("EC", "SunEC");
95 } catch (NoSuchAlgorithmException | NoSuchProviderException e) {
96 throw new RuntimeException(e);
97 }
98 }
99
100 public static ECPublicKey decodeX509ECPublicKey(byte[] encoded)
101 throws InvalidKeySpecException {
102 KeyFactory keyFactory = getKeyFactory();
103 X509EncodedKeySpec keySpec = new X509EncodedKeySpec(encoded);
104
105 return (ECPublicKey)keyFactory.generatePublic(keySpec);
106 }
107
108 public static byte[] x509EncodeECPublicKey(ECPoint w,
109 ECParameterSpec params) throws InvalidKeySpecException {
110 KeyFactory keyFactory = getKeyFactory();
111 ECPublicKeySpec keySpec = new ECPublicKeySpec(w, params);
112 X509Key key = (X509Key)keyFactory.generatePublic(keySpec);
113
114 return key.getEncoded();
115 }
116
117 public static ECPrivateKey decodePKCS8ECPrivateKey(byte[] encoded)
118 throws InvalidKeySpecException {
119 KeyFactory keyFactory = getKeyFactory();
120 PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(encoded);
121
122 return (ECPrivateKey)keyFactory.generatePrivate(keySpec);
123 }
124
125 public static ECPrivateKey generateECPrivateKey(BigInteger s,
126 ECParameterSpec params) throws InvalidKeySpecException {
127 KeyFactory keyFactory = getKeyFactory();
128 ECPrivateKeySpec keySpec = new ECPrivateKeySpec(s, params);
129
130 return (ECPrivateKey)keyFactory.generatePrivate(keySpec);
131 }
132
133 public static AlgorithmParameters getECParameters(Provider p) {
134 try {
135 if (p != null) {
136 return AlgorithmParameters.getInstance("EC", p);
137 }
138
139 return AlgorithmParameters.getInstance("EC");
140 } catch (NoSuchAlgorithmException nsae) {
141 throw new RuntimeException(nsae);
142 }
143 }
144
145 public static byte[] encodeECParameterSpec(Provider p,
146 ECParameterSpec spec) {
147 AlgorithmParameters parameters = getECParameters(p);
148
149 try {
150 parameters.init(spec);
151 } catch (InvalidParameterSpecException ipse) {
152 throw new RuntimeException("Not a known named curve: " + spec);
153 }
154
155 try {
156 return parameters.getEncoded();
157 } catch (IOException ioe) {
158 // it is a bug if this should happen
159 throw new RuntimeException(ioe);
160 }
161 }
162
163 public static ECParameterSpec getECParameterSpec(Provider p,
164 ECParameterSpec spec) {
165 AlgorithmParameters parameters = getECParameters(p);
166
167 try {
168 parameters.init(spec);
169 return parameters.getParameterSpec(ECParameterSpec.class);
170 } catch (InvalidParameterSpecException ipse) {
171 return null;
172 }
173 }
174
175 public static ECParameterSpec getECParameterSpec(Provider p,
176 byte[] params)
177 throws IOException {
178 AlgorithmParameters parameters = getECParameters(p);
179
180 parameters.init(params);
181
182 try {
183 return parameters.getParameterSpec(ECParameterSpec.class);
184 } catch (InvalidParameterSpecException ipse) {
185 return null;
186 }
187 }
188
189 public static ECParameterSpec getECParameterSpec(Provider p, String name) {
190 AlgorithmParameters parameters = getECParameters(p);
191
192 try {
193 parameters.init(new ECGenParameterSpec(name));
194 return parameters.getParameterSpec(ECParameterSpec.class);
195 } catch (InvalidParameterSpecException ipse) {
196 return null;
197 }
198 }
199
200 public static ECParameterSpec getECParameterSpec(Provider p, int keySize) {
201 AlgorithmParameters parameters = getECParameters(p);
202
203 try {
204 parameters.init(new ECKeySizeParameterSpec(keySize));
205 return parameters.getParameterSpec(ECParameterSpec.class);
206 } catch (InvalidParameterSpecException ipse) {
207 return null;
208 }
209
210 }
211
212 public static String getCurveName(Provider p, ECParameterSpec spec) {
213 ECGenParameterSpec nameSpec;
214 AlgorithmParameters parameters = getECParameters(p);
215
216 try {
217 parameters.init(spec);
218 nameSpec = parameters.getParameterSpec(ECGenParameterSpec.class);
219 } catch (InvalidParameterSpecException ipse) {
220 return null;
221 }
222
223 if (nameSpec == null) {
224 return null;
225 }
226
227 return nameSpec.getName();
228 }
229
230 private ECUtil() {}
231 }