Refactor on GMKeyExchangeSpi

Author: gefeili

prov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/ec/GMKeyExchangeSpi.java

@@ -1,6 +1,5 @@
 package org.bouncycastle.jcajce.provider.asymmetric.ec;
 
-import java.math.BigInteger;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.InvalidKeyException;
 import java.security.Key;
@@ -9,10 +8,6 @@
 import java.security.SecureRandom;
 import java.security.spec.AlgorithmParameterSpec;
 
-import org.bouncycastle.asn1.x9.X9IntegerConverter;
-import org.bouncycastle.crypto.BasicAgreement;
-import org.bouncycastle.crypto.CipherParameters;
-import org.bouncycastle.crypto.DerivationFunction;
 import org.bouncycastle.crypto.agreement.SM2KeyExchange;
 import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
@@ -21,44 +16,31 @@
 import org.bouncycastle.crypto.params.SM2KeyExchangePublicParameters;
 import org.bouncycastle.jcajce.provider.asymmetric.util.BaseAgreementSpi;
 import org.bouncycastle.jcajce.spec.SM2KeyExchangeSpec;
-import org.bouncycastle.jce.interfaces.ECPrivateKey;
 import org.bouncycastle.util.Arrays;
 
 
 public class GMKeyExchangeSpi
     extends BaseAgreementSpi
 {
-    private static final X9IntegerConverter converter = new X9IntegerConverter();
-
     private final String kaAlgorithm;
-    private ParametersWithID parameters;
-    private final BasicAgreement agreement;
+    private final SM2KeyExchange engine;
     private SM2KeyExchangeSpec  spec;
     private byte[] result;
 
-    protected GMKeyExchangeSpi(
-        String kaAlgorithm,
-        BasicAgreement agreement,
-        DerivationFunction kdf)
+    protected GMKeyExchangeSpi(String kaAlgorithm)
     {
-        super(kaAlgorithm, kdf);
+        super(kaAlgorithm, null);
 
         this.kaAlgorithm = kaAlgorithm;
-        this.agreement = agreement;
-    }
-
-    protected byte[] bigIntToBytes(
-        BigInteger r, BCECPublicKey key)
-    {
-        return converter.integerToBytes(r, converter.getByteLength(key.engineGetSpec().getCurve()));
+        this.engine = new SM2KeyExchange();
     }
 
     protected Key engineDoPhase(
         Key key,
         boolean lastPhase)
         throws InvalidKeyException, IllegalStateException
     {
-        if (parameters == null)
+        if (spec == null)
         {
             throw new IllegalStateException(kaAlgorithm + " not initialised.");
         }
@@ -73,16 +55,13 @@ protected Key engineDoPhase(
             throw new InvalidKeyException(kaAlgorithm + " key agreement requires "
                 + getSimpleName(BCECPublicKey.class) + " for doPhase");
         }
-        BCECPublicKey k = (BCECPublicKey)key;
-        ECPublicKeyParameters staticKey = (ECPublicKeyParameters)
-            ECUtils.generatePublicKeyParameter((PublicKey)key);
-        ECPublicKeyParameters ephemKey = (ECPublicKeyParameters)
-            ECUtils.generatePublicKeyParameter(spec.getOtherPartyEphemeralKey());
+        ECPublicKeyParameters staticKey = (ECPublicKeyParameters)ECUtils.generatePublicKeyParameter((PublicKey)key);
+        ECPublicKeyParameters ephemeralKey = (ECPublicKeyParameters)ECUtils.generatePublicKeyParameter(spec.getOtherPartyEphemeralKey());
 
-        ParametersWithID parameters = new ParametersWithID(new SM2KeyExchangePublicParameters(staticKey, ephemKey),
+        ParametersWithID parameters = new ParametersWithID(new SM2KeyExchangePublicParameters(staticKey, ephemeralKey),
             spec.getOtherPartyId());
 
-        result = bigIntToBytes(agreement.calculateAgreement(parameters), k);
+        result = engine.calculateKey(128, parameters);
 
         return null;
     }
@@ -98,15 +77,14 @@ protected void doInitFromKey(Key key, AlgorithmParameterSpec parameterSpec, Secu
         if (!(key instanceof PrivateKey))
         {
             throw new InvalidKeyException(kaAlgorithm + " key agreement requires "
-                + getSimpleName(ECPrivateKey.class) + " for initialisation");
+                + getSimpleName(BCECPrivateKey.class) + " for initialisation");
         }
         spec = (SM2KeyExchangeSpec)parameterSpec;
-        byte[] id = spec.getId();
 
         ECPrivateKeyParameters staticKey = (ECPrivateKeyParameters)ECUtils.generatePrivateKeyParameter((PrivateKey)key);
         ECPrivateKeyParameters ephemeralKey = (ECPrivateKeyParameters)ECUtils.generatePrivateKeyParameter(spec.getEphemeralPrivateKey());
-        this.parameters = new ParametersWithID(new SM2KeyExchangePrivateParameters(spec.isInitiator(), staticKey, ephemeralKey), id);
-        agreement.init(parameters);
+        ParametersWithID parameters = new ParametersWithID(new SM2KeyExchangePrivateParameters(spec.isInitiator(), staticKey, ephemeralKey), spec.getId());
+        engine.init(parameters);
     }
 
     private static String getSimpleName(Class clazz)
@@ -126,39 +104,7 @@ public static class SM2
     {
         public SM2()
         {
-            super("SM2", new SM2KeyAgreement(), null);
-        }
-    }
-
-    private static class SM2KeyAgreement
-        implements BasicAgreement
-    {
-        private final SM2KeyExchange engine;
-        private int fieldSize;
-        public SM2KeyAgreement()
-        {
-            engine = new SM2KeyExchange();
-        }
-
-        @Override
-        public void init(CipherParameters param)
-        {
-            engine.init(param);
-            fieldSize = ((SM2KeyExchangePrivateParameters)((ParametersWithID)param).getParameters()).getStaticPrivateKey()
-                .getParameters().getCurve().getFieldElementEncodingLength();
-        }
-
-        @Override
-        public int getFieldSize()
-        {
-            return fieldSize;
-        }
-
-        @Override
-        public BigInteger calculateAgreement(CipherParameters pubKey)
-        {
-            byte[] rlt = engine.calculateKey(128, pubKey);
-            return new BigInteger(1, rlt);
+            super("SM2");
         }
     }
 }