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1: /* GnuRSAPublicKey.java -- 2: Copyright 2001, 2002, 2003, 2006 Free Software Foundation, Inc. 3: 4: This file is a part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2 of the License, or (at 9: your option) any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; if not, write to the Free Software 18: Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19: USA 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package gnu.java.security.key.rsa; 40: 41: import gnu.java.security.Registry; 42: import gnu.java.security.action.GetPropertyAction; 43: import gnu.java.security.key.IKeyPairCodec; 44: 45: import java.math.BigInteger; 46: import java.security.AccessController; 47: import java.security.PublicKey; 48: import java.security.interfaces.RSAPublicKey; 49: 50: /** 51: * An object that encapsulates an RSA public key. 52: * <p> 53: * References: 54: * <ol> 55: * <li><a 56: * href="http://www.cosic.esat.kuleuven.ac.be/nessie/workshop/submissions/rsa-pss.zip"> 57: * RSA-PSS Signature Scheme with Appendix, part B.</a><br> 58: * Primitive specification and supporting documentation.<br> 59: * Jakob Jonsson and Burt Kaliski.</li> 60: * </ol> 61: */ 62: public class GnuRSAPublicKey 63: extends GnuRSAKey 64: implements PublicKey, RSAPublicKey 65: { 66: /** String representation of this key. Cached for speed. */ 67: private transient String str; 68: 69: /** 70: * Conveience constructor. Calls the constructor with 3 arguments passing 71: * {@link Registry#RAW_ENCODING_ID} as the identifier of the preferred 72: * encoding format. 73: * 74: * @param n the modulus. 75: * @param e the public exponent. 76: */ 77: public GnuRSAPublicKey(final BigInteger n, final BigInteger e) 78: { 79: this(Registry.RAW_ENCODING_ID, n, e); 80: } 81: 82: /** 83: * Constructs a new instance of <code>GnuRSAPublicKey</code> given the 84: * designated arguments. 85: * 86: * @param preferredFormat the identifier of the preferred encoding format to 87: * use when externalizing this key. 88: * @param n the modulus. 89: * @param e the public exponent. 90: */ 91: public GnuRSAPublicKey(int preferredFormat, BigInteger n, BigInteger e) 92: { 93: super(preferredFormat == Registry.ASN1_ENCODING_ID ? Registry.X509_ENCODING_ID 94: : preferredFormat, 95: n, e); 96: } 97: 98: /** 99: * A class method that takes the output of the <code>encodePublicKey()</code> 100: * method of an RSA keypair codec object (an instance implementing 101: * {@link IKeyPairCodec} for RSA keys, and re-constructs an instance of this 102: * object. 103: * 104: * @param k the contents of a previously encoded instance of this object. 105: * @throws ArrayIndexOutOfBoundsException if there is not enough bytes, in 106: * <code>k</code>, to represent a valid encoding of an instance 107: * of this object. 108: * @throws IllegalArgumentException if the byte sequence does not represent a 109: * valid encoding of an instance of this object. 110: */ 111: public static GnuRSAPublicKey valueOf(final byte[] k) 112: { 113: // try RAW codec 114: if (k[0] == Registry.MAGIC_RAW_RSA_PUBLIC_KEY[0]) 115: try 116: { 117: return (GnuRSAPublicKey) new RSAKeyPairRawCodec().decodePublicKey(k); 118: } 119: catch (IllegalArgumentException ignored) 120: { 121: } 122: // try X.509 codec 123: return (GnuRSAPublicKey) new RSAKeyPairX509Codec().decodePublicKey(k); 124: } 125: 126: /** 127: * Returns the encoded form of this public key according to the designated 128: * format. 129: * 130: * @param format the desired format identifier of the resulting encoding. 131: * @return the byte sequence encoding this key according to the designated 132: * format. 133: * @throws IllegalArgumentException if the format is not supported. 134: * @see RSAKeyPairRawCodec 135: */ 136: public byte[] getEncoded(final int format) 137: { 138: final byte[] result; 139: switch (format) 140: { 141: case IKeyPairCodec.RAW_FORMAT: 142: result = new RSAKeyPairRawCodec().encodePublicKey(this); 143: break; 144: case IKeyPairCodec.X509_FORMAT: 145: result = new RSAKeyPairX509Codec().encodePublicKey(this); 146: break; 147: default: 148: throw new IllegalArgumentException("Unsupported encoding format: " 149: + format); 150: } 151: return result; 152: } 153: 154: /** 155: * Returns <code>true</code> if the designated object is an instance of this 156: * class and has the same RSA parameter values as this one. 157: * 158: * @param obj the other non-null RSA key to compare to. 159: * @return <code>true</code> if the designated object is of the same type 160: * and value as this one. 161: */ 162: public boolean equals(final Object obj) 163: { 164: if (obj == null) 165: return false; 166: 167: if (! (obj instanceof RSAPublicKey)) 168: return false; 169: 170: final RSAPublicKey that = (RSAPublicKey) obj; 171: return super.equals(that) 172: && getPublicExponent().equals(that.getPublicExponent()); 173: } 174: 175: public String toString() 176: { 177: if (str == null) 178: { 179: String ls = (String) AccessController.doPrivileged 180: (new GetPropertyAction("line.separator")); 181: str = new StringBuilder(this.getClass().getName()).append("(") 182: .append(super.toString()).append(",").append(ls) 183: .append(")") 184: .toString(); 185: } 186: return str; 187: } 188: }