1 files changed, 189 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/crypto/params/DHParameters.java b/core/src/main/java/org/spongycastle/crypto/params/DHParameters.java
new file mode 100644
index 00000000..d4f03ff3
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/crypto/params/DHParameters.java
@@ -0,0 +1,189 @@
+package org.spongycastle.crypto.params;
+
+import java.math.BigInteger;
+
+import org.spongycastle.crypto.CipherParameters;
+
+public class DHParameters
+    implements CipherParameters
+{
+    private static final int DEFAULT_MINIMUM_LENGTH = 160;
+
+    // not final due to compiler bug in "simpler" JDKs
+    private BigInteger              g;
+    private BigInteger              p;
+    private BigInteger              q;
+    private BigInteger              j;
+    private int                     m;
+    private int                     l;
+    private DHValidationParameters  validation;
+
+    private static int getDefaultMParam(
+        int lParam)
+    {
+        if (lParam == 0)
+        {
+            return DEFAULT_MINIMUM_LENGTH;
+        }
+
+        return lParam < DEFAULT_MINIMUM_LENGTH ? lParam : DEFAULT_MINIMUM_LENGTH;
+    }
+
+    public DHParameters(
+        BigInteger  p,
+        BigInteger  g)
+    {
+        this(p, g, null, 0);
+    }
+
+    public DHParameters(
+        BigInteger  p,
+        BigInteger  g,
+        BigInteger  q)
+    {
+        this(p, g, q, 0);
+    }
+
+    public DHParameters(
+        BigInteger  p,
+        BigInteger  g,
+        BigInteger  q,
+        int         l)
+    {
+        this(p, g, q, getDefaultMParam(l), l, null, null);
+    }
+
+    public DHParameters(
+        BigInteger  p,
+        BigInteger  g,
+        BigInteger  q,
+        int         m,
+        int         l)
+    {
+        this(p, g, q, m, l, null, null);
+    }
+
+    public DHParameters(
+        BigInteger              p,
+        BigInteger              g,
+        BigInteger              q,
+        BigInteger              j,
+        DHValidationParameters  validation)
+    {
+        this(p, g, q, DEFAULT_MINIMUM_LENGTH, 0, j, validation);
+    }
+
+    public DHParameters(
+        BigInteger              p,
+        BigInteger              g,
+        BigInteger              q,
+        int                     m,
+        int                     l,
+        BigInteger              j,
+        DHValidationParameters  validation)
+    {
+        if (l != 0)
+        {
+            BigInteger bigL = BigInteger.valueOf(2L ^ (l - 1));
+            if (bigL.compareTo(p) == 1)
+            {
+                throw new IllegalArgumentException("when l value specified, it must satisfy 2^(l-1) <= p");
+            }
+            if (l < m)
+            {
+                throw new IllegalArgumentException("when l value specified, it may not be less than m value");
+            }
+        }
+
+        this.g = g;
+        this.p = p;
+        this.q = q;
+        this.m = m;
+        this.l = l;
+        this.j = j;
+        this.validation = validation;
+    }
+
+    public BigInteger getP()
+    {
+        return p;
+    }
+
+    public BigInteger getG()
+    {
+        return g;
+    }
+
+    public BigInteger getQ()
+    {
+        return q;
+    }
+
+    /**
+     * Return the subgroup factor J.
+     *
+     * @return subgroup factor
+     */
+    public BigInteger getJ()
+    {
+        return j;
+    }
+
+    /**
+     * Return the minimum length of the private value.
+     *
+     * @return the minimum length of the private value in bits.
+     */
+    public int getM()
+    {
+        return m;
+    }
+
+    /**
+     * Return the private value length in bits - if set, zero otherwise
+     *
+     * @return the private value length in bits, zero otherwise.
+     */
+    public int getL()
+    {
+        return l;
+    }
+
+    public DHValidationParameters getValidationParameters()
+    {
+        return validation;
+    }
+
+    public boolean equals(
+        Object  obj)
+    {
+        if (!(obj instanceof DHParameters))
+        {
+            return false;
+        }
+
+        DHParameters    pm = (DHParameters)obj;
+
+        if (this.getQ() != null)
+        {
+            if (!this.getQ().equals(pm.getQ()))
+            {
+                return false;
+            }
+        }
+        else
+        {
+            if (pm.getQ() != null)
+            {
+                return false;
+            }
+        }
+
+        return pm.getP().equals(p) && pm.getG().equals(g);
+    }
+    
+    public int hashCode()
+    {
+        return getP().hashCode() ^ getG().hashCode() ^ (getQ() != null ? getQ().hashCode() : 0);
+    }
+}