1 package org.bouncycastle.crypto.params; 2 3 import org.bouncycastle.crypto.CipherParameters; 4 5 import java.math.BigInteger; 6 7 public class DHParameters 8 implements CipherParameters 9 { 10 private static final int DEFAULT_MINIMUM_LENGTH = 160; 11 12 // not final due to compiler bug in "simpler" JDKs 13 private BigInteger g; 14 private BigInteger p; 15 private BigInteger q; 16 private BigInteger j; 17 private int m; 18 private int l; 19 private DHValidationParameters validation; 20 21 private static int getDefaultMParam( 22 int lParam) 23 { 24 if (lParam == 0) 25 { 26 return DEFAULT_MINIMUM_LENGTH; 27 } 28 29 return lParam < DEFAULT_MINIMUM_LENGTH ? lParam : DEFAULT_MINIMUM_LENGTH; 30 } 31 32 public DHParameters( 33 BigInteger p, 34 BigInteger g) 35 { 36 this(p, g, null, 0); 37 } 38 39 public DHParameters( 40 BigInteger p, 41 BigInteger g, 42 BigInteger q) 43 { 44 this(p, g, q, 0); 45 } 46 47 public DHParameters( 48 BigInteger p, 49 BigInteger g, 50 BigInteger q, 51 int l) 52 { 53 this(p, g, q, getDefaultMParam(l), l, null, null); 54 } 55 56 public DHParameters( 57 BigInteger p, 58 BigInteger g, 59 BigInteger q, 60 int m, 61 int l) 62 { 63 this(p, g, q, m, l, null, null); 64 } 65 66 public DHParameters( 67 BigInteger p, 68 BigInteger g, 69 BigInteger q, 70 BigInteger j, 71 DHValidationParameters validation) 72 { 73 this(p, g, q, DEFAULT_MINIMUM_LENGTH, 0, j, validation); 74 } 75 76 public DHParameters( 77 BigInteger p, 78 BigInteger g, 79 BigInteger q, 80 int m, 81 int l, 82 BigInteger j, 83 DHValidationParameters validation) 84 { 85 if (l != 0) 86 { 87 if (l >= p.bitLength()) 88 { 89 throw new IllegalArgumentException("when l value specified, it must be less than bitlength(p)"); 90 } 91 if (l < m) 92 { 93 throw new IllegalArgumentException("when l value specified, it may not be less than m value"); 94 } 95 } 96 97 this.g = g; 98 this.p = p; 99 this.q = q; 100 this.m = m; 101 this.l = l; 102 this.j = j; 103 this.validation = validation; 104 } 105 106 public BigInteger getP() 107 { 108 return p; 109 } 110 111 public BigInteger getG() 112 { 113 return g; 114 } 115 116 public BigInteger getQ() 117 { 118 return q; 119 } 120 121 /** 122 * Return the subgroup factor J. 123 * 124 * @return subgroup factor 125 */ 126 public BigInteger getJ() 127 { 128 return j; 129 } 130 131 /** 132 * Return the minimum length of the private value. 133 * 134 * @return the minimum length of the private value in bits. 135 */ 136 public int getM() 137 { 138 return m; 139 } 140 141 /** 142 * Return the private value length in bits - if set, zero otherwise 143 * 144 * @return the private value length in bits, zero otherwise. 145 */ 146 public int getL() 147 { 148 return l; 149 } 150 151 public DHValidationParameters getValidationParameters() 152 { 153 return validation; 154 } 155 156 public boolean equals( 157 Object obj) 158 { 159 if (!(obj instanceof DHParameters)) 160 { 161 return false; 162 } 163 164 DHParameters pm = (DHParameters)obj; 165 166 if (this.getQ() != null) 167 { 168 if (!this.getQ().equals(pm.getQ())) 169 { 170 return false; 171 } 172 } 173 else 174 { 175 if (pm.getQ() != null) 176 { 177 return false; 178 } 179 } 180 181 return pm.getP().equals(p) && pm.getG().equals(g); 182 } 183 184 public int hashCode() 185 { 186 return getP().hashCode() ^ getG().hashCode() ^ (getQ() != null ? getQ().hashCode() : 0); 187 } 188 } 189
