1 files changed, 77 insertions, 0 deletions
diff --git a/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/dh/AlgorithmParameterGeneratorSpi.java b/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/dh/AlgorithmParameterGeneratorSpi.java
new file mode 100644
index 000000000..0b3942877
--- /dev/null
+++ b/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/dh/AlgorithmParameterGeneratorSpi.java
@@ -0,0 +1,77 @@
+package org.spongycastle.jcajce.provider.asymmetric.dh;
+
+import java.security.AlgorithmParameters;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.SecureRandom;
+import java.security.spec.AlgorithmParameterSpec;
+
+import javax.crypto.spec.DHGenParameterSpec;
+import javax.crypto.spec.DHParameterSpec;
+
+import org.spongycastle.crypto.generators.DHParametersGenerator;
+import org.spongycastle.crypto.params.DHParameters;
+import org.spongycastle.jce.provider.BouncyCastleProvider;
+
+public class AlgorithmParameterGeneratorSpi
+    extends java.security.AlgorithmParameterGeneratorSpi
+{
+    protected SecureRandom random;
+    protected int strength = 1024;
+
+    private int l = 0;
+
+    protected void engineInit(
+        int strength,
+        SecureRandom random)
+    {
+        this.strength = strength;
+        this.random = random;
+    }
+
+    protected void engineInit(
+        AlgorithmParameterSpec genParamSpec,
+        SecureRandom random)
+        throws InvalidAlgorithmParameterException
+    {
+        if (!(genParamSpec instanceof DHGenParameterSpec))
+        {
+            throw new InvalidAlgorithmParameterException("DH parameter generator requires a DHGenParameterSpec for initialisation");
+        }
+        DHGenParameterSpec spec = (DHGenParameterSpec)genParamSpec;
+
+        this.strength = spec.getPrimeSize();
+        this.l = spec.getExponentSize();
+        this.random = random;
+    }
+
+    protected AlgorithmParameters engineGenerateParameters()
+    {
+        DHParametersGenerator pGen = new DHParametersGenerator();
+
+        if (random != null)
+        {
+            pGen.init(strength, 20, random);
+        }
+        else
+        {
+            pGen.init(strength, 20, new SecureRandom());
+        }
+
+        DHParameters p = pGen.generateParameters();
+
+        AlgorithmParameters params;
+
+        try
+        {
+            params = AlgorithmParameters.getInstance("DH", BouncyCastleProvider.PROVIDER_NAME);
+            params.init(new DHParameterSpec(p.getP(), p.getG(), l));
+        }
+        catch (Exception e)
+        {
+            throw new RuntimeException(e.getMessage());
+        }
+
+        return params;
+    }
+
+}