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1: /* GnuDSAPublicKey.java --- Gnu DSA Public Key 2: Copyright (C) 1999,2003,2004 Free Software Foundation, Inc. 3: 4: This file is 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, or (at your option) 9: 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; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 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.provider; 40: 41: import gnu.java.security.OID; 42: import gnu.java.security.der.BitString; 43: import gnu.java.security.der.DER; 44: import gnu.java.security.der.DERValue; 45: import gnu.java.security.der.DERWriter; 46: 47: import java.io.ByteArrayOutputStream; 48: import java.io.IOException; 49: import java.math.BigInteger; 50: import java.security.interfaces.DSAParams; 51: import java.security.interfaces.DSAPublicKey; 52: import java.security.spec.DSAParameterSpec; 53: import java.util.ArrayList; 54: 55: public class GnuDSAPublicKey implements DSAPublicKey 56: { 57: private byte[] encodedKey; 58: BigInteger y; 59: BigInteger p; 60: BigInteger q; 61: BigInteger g; 62: 63: public GnuDSAPublicKey(BigInteger y, BigInteger p, BigInteger q, BigInteger g ) 64: { 65: this.y = y; 66: this.p = p; 67: this.q = q; 68: this.g = g; 69: } 70: 71: public String getAlgorithm() 72: { 73: return "DSA"; 74: } 75: 76: public String getFormat() 77: { 78: return "X.509"; 79: } 80: 81: /** 82: * The encoded form of DSA public keys is: 83: * 84: * <blockquote><pre> 85: * SubjectPublicKeyInfo ::= SEQUENCE { 86: * algorithm AlgorithmIdentifier, 87: * subjectPublicKey BIT STRING } 88: * </pre></blockquote> 89: */ 90: public byte[] getEncoded() 91: { 92: if (encodedKey != null) 93: return (byte[]) encodedKey.clone(); 94: try 95: { 96: ByteArrayOutputStream out = new ByteArrayOutputStream(); 97: ArrayList spki = new ArrayList(2); 98: ArrayList alg = new ArrayList(2); 99: alg.add(new DERValue(DER.OBJECT_IDENTIFIER, 100: new OID("1.2.840.113549.1.1.1"))); 101: ArrayList params = new ArrayList(3); 102: params.add(new DERValue(DER.INTEGER, p)); 103: params.add(new DERValue(DER.INTEGER, q)); 104: params.add(new DERValue(DER.INTEGER, g)); 105: alg.add(new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, params)); 106: spki.add(new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, alg)); 107: spki.add(new DERValue(DER.BIT_STRING, new BitString(y.toByteArray()))); 108: DERWriter.write(out, new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, spki)); 109: return (byte[]) (encodedKey = out.toByteArray()).clone(); 110: } 111: catch (IOException ioe) 112: { 113: return null; 114: } 115: } 116: 117: public DSAParams getParams() 118: { 119: if (p == null || q == null || g == null) 120: return null; 121: return (DSAParams)(new DSAParameterSpec(p,q,g)); 122: } 123: 124: public BigInteger getY() 125: { 126: return y; 127: } 128: 129: public String toString() 130: { 131: return 132: "GnuDSAPublicKey: y=" + (y != null ? y.toString(16) : "(null)") + 133: " p=" + (p != null ? p.toString(16) : "(null)") + 134: " q=" + (q != null ? q.toString(16) : "(null)") + 135: " g=" + (g != null ? g.toString(16) : "(null)"); 136: } 137: }