1 files changed, 178 insertions, 0 deletions
diff --git a/prov/src/main/java/org/spongycastle/jce/provider/JCEDHPublicKey.java b/prov/src/main/java/org/spongycastle/jce/provider/JCEDHPublicKey.java
new file mode 100644
index 00000000..c53e89d6
--- /dev/null
+++ b/prov/src/main/java/org/spongycastle/jce/provider/JCEDHPublicKey.java
@@ -0,0 +1,178 @@
+package org.spongycastle.jce.provider;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.math.BigInteger;
+
+import javax.crypto.interfaces.DHPublicKey;
+import javax.crypto.spec.DHParameterSpec;
+import javax.crypto.spec.DHPublicKeySpec;
+
+import org.spongycastle.asn1.ASN1Integer;
+import org.spongycastle.asn1.ASN1ObjectIdentifier;
+import org.spongycastle.asn1.ASN1Sequence;
+import org.spongycastle.asn1.pkcs.DHParameter;
+import org.spongycastle.asn1.pkcs.PKCSObjectIdentifiers;
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.asn1.x509.SubjectPublicKeyInfo;
+import org.spongycastle.asn1.x9.DHDomainParameters;
+import org.spongycastle.asn1.x9.X9ObjectIdentifiers;
+import org.spongycastle.crypto.params.DHPublicKeyParameters;
+import org.spongycastle.jcajce.provider.asymmetric.util.KeyUtil;
+
+public class JCEDHPublicKey
+    implements DHPublicKey
+{
+    static final long serialVersionUID = -216691575254424324L;
+    
+    private BigInteger              y;
+    private DHParameterSpec         dhSpec;
+    private SubjectPublicKeyInfo    info;
+    
+    JCEDHPublicKey(
+        DHPublicKeySpec    spec)
+    {
+        this.y = spec.getY();
+        this.dhSpec = new DHParameterSpec(spec.getP(), spec.getG());
+    }
+
+    JCEDHPublicKey(
+        DHPublicKey    key)
+    {
+        this.y = key.getY();
+        this.dhSpec = key.getParams();
+    }
+
+    JCEDHPublicKey(
+        DHPublicKeyParameters  params)
+    {
+        this.y = params.getY();
+        this.dhSpec = new DHParameterSpec(params.getParameters().getP(), params.getParameters().getG(), params.getParameters().getL());
+    }
+
+    JCEDHPublicKey(
+        BigInteger        y,
+        DHParameterSpec   dhSpec)
+    {
+        this.y = y;
+        this.dhSpec = dhSpec;
+    }
+
+    JCEDHPublicKey(
+        SubjectPublicKeyInfo    info)
+    {
+        this.info = info;
+
+        ASN1Integer              derY;
+        try
+        {
+            derY = (ASN1Integer)info.parsePublicKey();
+        }
+        catch (IOException e)
+        {
+            throw new IllegalArgumentException("invalid info structure in DH public key");
+        }
+
+        this.y = derY.getValue();
+
+        ASN1Sequence seq = ASN1Sequence.getInstance(info.getAlgorithmId().getParameters());
+        ASN1ObjectIdentifier id = info.getAlgorithmId().getAlgorithm();
+
+        // we need the PKCS check to handle older keys marked with the X9 oid.
+        if (id.equals(PKCSObjectIdentifiers.dhKeyAgreement) || isPKCSParam(seq))
+        {
+            DHParameter             params = DHParameter.getInstance(seq);
+
+            if (params.getL() != null)
+            {
+                this.dhSpec = new DHParameterSpec(params.getP(), params.getG(), params.getL().intValue());
+            }
+            else
+            {
+                this.dhSpec = new DHParameterSpec(params.getP(), params.getG());
+            }
+        }
+        else if (id.equals(X9ObjectIdentifiers.dhpublicnumber))
+        {
+            DHDomainParameters params = DHDomainParameters.getInstance(seq);
+
+            this.dhSpec = new DHParameterSpec(params.getP().getValue(), params.getG().getValue());
+        }
+        else
+        {
+            throw new IllegalArgumentException("unknown algorithm type: " + id);
+        }
+    }
+
+    public String getAlgorithm()
+    {
+        return "DH";
+    }
+
+    public String getFormat()
+    {
+        return "X.509";
+    }
+
+    public byte[] getEncoded()
+    {
+        if (info != null)
+        {
+            return KeyUtil.getEncodedSubjectPublicKeyInfo(info);
+        }
+
+        return KeyUtil.getEncodedSubjectPublicKeyInfo(new AlgorithmIdentifier(PKCSObjectIdentifiers.dhKeyAgreement, new DHParameter(dhSpec.getP(), dhSpec.getG(), dhSpec.getL())), new ASN1Integer(y));
+    }
+
+    public DHParameterSpec getParams()
+    {
+        return dhSpec;
+    }
+
+    public BigInteger getY()
+    {
+        return y;
+    }
+
+    private boolean isPKCSParam(ASN1Sequence seq)
+    {
+        if (seq.size() == 2)
+        {
+            return true;
+        }
+        
+        if (seq.size() > 3)
+        {
+            return false;
+        }
+
+        ASN1Integer l = ASN1Integer.getInstance(seq.getObjectAt(2));
+        ASN1Integer p = ASN1Integer.getInstance(seq.getObjectAt(0));
+
+        if (l.getValue().compareTo(BigInteger.valueOf(p.getValue().bitLength())) > 0)
+        {
+            return false;
+        }
+
+        return true;
+    }
+
+    private void readObject(
+        ObjectInputStream   in)
+        throws IOException, ClassNotFoundException
+    {
+        this.y = (BigInteger)in.readObject();
+        this.dhSpec = new DHParameterSpec((BigInteger)in.readObject(), (BigInteger)in.readObject(), in.readInt());
+    }
+
+    private void writeObject(
+        ObjectOutputStream  out)
+        throws IOException
+    {
+        out.writeObject(this.getY());
+        out.writeObject(dhSpec.getP());
+        out.writeObject(dhSpec.getG());
+        out.writeInt(dhSpec.getL());
+    }
+}