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1: /* DSSKey.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.dss; 40: 41: import gnu.java.security.Registry; 42: import gnu.java.security.action.GetPropertyAction; 43: import gnu.java.security.util.FormatUtil; 44: 45: import java.math.BigInteger; 46: import java.security.AccessController; 47: import java.security.Key; 48: import java.security.interfaces.DSAKey; 49: import java.security.interfaces.DSAParams; 50: import java.security.spec.DSAParameterSpec; 51: 52: /** 53: * A base asbtract class for both public and private DSS (Digital Signature 54: * Standard) keys. It encapsulates the three DSS numbers: <code>p</code>, 55: * <code>q</code> and <code>g</code>. 56: * <p> 57: * According to the JDK, cryptographic <i>Keys</i> all have a <i>format</i>. 58: * The format used in this implementation is called <i>Raw</i>, and basically 59: * consists of the raw byte sequences of algorithm parameters. The exact order 60: * of the byte sequences and the implementation details are given in each of the 61: * relevant <code>getEncoded()</code> methods of each of the private and 62: * public keys. 63: * <p> 64: * <b>IMPORTANT</b>: Under certain circumstances (e.g. in an X.509 certificate 65: * with inherited AlgorithmIdentifier's parameters of a SubjectPublicKeyInfo 66: * element) these three MPIs may be <code>null</code>. 67: * 68: * @see DSSPrivateKey#getEncoded 69: * @see DSSPublicKey#getEncoded 70: */ 71: public abstract class DSSKey 72: implements Key, DSAKey 73: { 74: /** 75: * A prime modulus, where 76: * <code>2<sup>L-1</sup> < p < 2<sup>L</sup></code> for 77: * <code>512 <= L <= 1024</code> and <code>L</code> a multiple of 78: * <code>64</code>. 79: */ 80: protected final BigInteger p; 81: 82: /** 83: * A prime divisor of <code>p - 1</code>, where 84: * <code>2<sup>159</sup> < q 85: * < 2<sup>160</sup></code>. 86: */ 87: protected final BigInteger q; 88: 89: /** 90: * <code>g = h<sup>(p-1)</sup>/q mod p</code>, where <code>h</code> is 91: * any integer with <code>1 < h < p - 1</code> such that <code>h<sup> 92: * (p-1)</sup>/q mod p > 1</code> (<code>g</code> 93: * has order <code>q mod p 94: * </code>). 95: */ 96: protected final BigInteger g; 97: 98: /** 99: * Identifier of the default encoding format to use when externalizing the key 100: * material. 101: */ 102: protected final int defaultFormat; 103: 104: /** String representation of this key. Cached for speed. */ 105: private transient String str; 106: 107: /** 108: * Trivial protected constructor. 109: * 110: * @param defaultFormat the identifier of the encoding format to use by 111: * default when externalizing the key. 112: * @param p the DSS parameter <code>p</code>. 113: * @param q the DSS parameter <code>q</code>. 114: * @param g the DSS parameter <code>g</code>. 115: */ 116: protected DSSKey(int defaultFormat, BigInteger p, BigInteger q, BigInteger g) 117: { 118: super(); 119: 120: this.defaultFormat = defaultFormat <= 0 ? Registry.RAW_ENCODING_ID 121: : defaultFormat; 122: this.p = p; 123: this.q = q; 124: this.g = g; 125: } 126: 127: public DSAParams getParams() 128: { 129: return new DSAParameterSpec(p, q, g); 130: } 131: 132: public String getAlgorithm() 133: { 134: return Registry.DSS_KPG; 135: } 136: 137: /** @deprecated see getEncoded(int). */ 138: public byte[] getEncoded() 139: { 140: return getEncoded(defaultFormat); 141: } 142: 143: public String getFormat() 144: { 145: return FormatUtil.getEncodingShortName(defaultFormat); 146: } 147: 148: /** 149: * Returns <code>true</code> if the designated object is an instance of 150: * {@link DSAKey} and has the same DSS (Digital Signature Standard) parameter 151: * values as this one. 152: * <p> 153: * Always returns <code>false</code> if the MPIs of this key are 154: * <i>inherited</i>. This may be the case when the key is re-constructed from 155: * an X.509 certificate with absent or NULL AlgorithmIdentifier's parameters 156: * field. 157: * 158: * @param obj the other non-null DSS 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(Object obj) 163: { 164: if (hasInheritedParameters()) 165: return false; 166: 167: if (obj == null) 168: return false; 169: 170: if (! (obj instanceof DSAKey)) 171: return false; 172: 173: DSAKey that = (DSAKey) obj; 174: return p.equals(that.getParams().getP()) 175: && q.equals(that.getParams().getQ()) 176: && g.equals(that.getParams().getG()); 177: } 178: 179: public String toString() 180: { 181: if (str == null) 182: { 183: String ls = (String) AccessController.doPrivileged(new GetPropertyAction("line.separator")); 184: StringBuilder sb = new StringBuilder(ls) 185: .append("defaultFormat=").append(defaultFormat).append(",") 186: .append(ls); 187: if (hasInheritedParameters()) 188: sb.append("p=inherited,").append(ls) 189: .append("q=inherited,").append(ls) 190: .append("g=inherited"); 191: else 192: sb.append("p=0x").append(p.toString(16)).append(",").append(ls) 193: .append("q=0x").append(q.toString(16)).append(",").append(ls) 194: .append("g=0x").append(g.toString(16)); 195: str = sb.toString(); 196: } 197: return str; 198: } 199: 200: public abstract byte[] getEncoded(int format); 201: 202: /** 203: * @return <code>true</code> if <code>p</code>, <code>q</code> and 204: * <code>g</code> are all <code>null</code>. Returns 205: * <code>false</code> otherwise. 206: */ 207: public boolean hasInheritedParameters() 208: { 209: return p == null && q == null && g == null; 210: } 211: }