1/*
2 * Copyright (c) 2003, 2017, 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
26package sun.security.rsa;
27
28import java.io.IOException;
29import java.math.BigInteger;
30
31import java.security.*;
32import java.security.interfaces.*;
33
34import sun.security.util.*;
35import sun.security.x509.X509Key;
36
37/**
38 * Key implementation for RSA public keys.
39 *
40 * Note: RSA keys must be at least 512 bits long
41 *
42 * @see RSAPrivateCrtKeyImpl
43 * @see RSAKeyFactory
44 *
45 * @since   1.5
46 * @author  Andreas Sterbenz
47 */
48public final class RSAPublicKeyImpl extends X509Key implements RSAPublicKey {
49
50    private static final long serialVersionUID = 2644735423591199609L;
51
52    private BigInteger n;       // modulus
53    private BigInteger e;       // public exponent
54
55    /**
56     * Construct a key from its components. Used by the
57     * RSAKeyFactory and the RSAKeyPairGenerator.
58     */
59    public RSAPublicKeyImpl(BigInteger n, BigInteger e)
60            throws InvalidKeyException {
61        this.n = n;
62        this.e = e;
63        RSAKeyFactory.checkRSAProviderKeyLengths(n.bitLength(), e);
64        // generate the encoding
65        algid = RSAPrivateCrtKeyImpl.rsaId;
66        try {
67            DerOutputStream out = new DerOutputStream();
68            out.putInteger(n);
69            out.putInteger(e);
70            byte[] keyArray =
71                new DerValue(DerValue.tag_Sequence,
72                             out.toByteArray()).toByteArray();
73            setKey(new BitArray(keyArray.length*8, keyArray));
74        } catch (IOException exc) {
75            // should never occur
76            throw new InvalidKeyException(exc);
77        }
78    }
79
80    /**
81     * Construct a key from its encoding. Used by RSAKeyFactory.
82     */
83    public RSAPublicKeyImpl(byte[] encoded) throws InvalidKeyException {
84        decode(encoded);
85        RSAKeyFactory.checkRSAProviderKeyLengths(n.bitLength(), e);
86    }
87
88    // see JCA doc
89    public String getAlgorithm() {
90        return "RSA";
91    }
92
93    // see JCA doc
94    public BigInteger getModulus() {
95        return n;
96    }
97
98    // see JCA doc
99    public BigInteger getPublicExponent() {
100        return e;
101    }
102
103    /**
104     * Parse the key. Called by X509Key.
105     */
106    protected void parseKeyBits() throws InvalidKeyException {
107        try {
108            DerInputStream in = new DerInputStream(getKey().toByteArray());
109            DerValue derValue = in.getDerValue();
110            if (derValue.tag != DerValue.tag_Sequence) {
111                throw new IOException("Not a SEQUENCE");
112            }
113            DerInputStream data = derValue.data;
114            n = data.getPositiveBigInteger();
115            e = data.getPositiveBigInteger();
116            if (derValue.data.available() != 0) {
117                throw new IOException("Extra data available");
118            }
119        } catch (IOException e) {
120            throw new InvalidKeyException("Invalid RSA public key", e);
121        }
122    }
123
124    // return a string representation of this key for debugging
125    public String toString() {
126        return "Sun RSA public key, " + n.bitLength() + " bits\n  modulus: "
127                + n + "\n  public exponent: " + e;
128    }
129
130    protected Object writeReplace() throws java.io.ObjectStreamException {
131        return new KeyRep(KeyRep.Type.PUBLIC,
132                        getAlgorithm(),
133                        getFormat(),
134                        getEncoded());
135    }
136}
137