1 files changed, 152 insertions, 0 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/util/PrivateKeyFactory.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/util/PrivateKeyFactory.java
new file mode 100644
index 000000000..750c6ac55
--- /dev/null
+++ b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/util/PrivateKeyFactory.java
@@ -0,0 +1,152 @@
+package org.spongycastle.crypto.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigInteger;
+
+import org.spongycastle.asn1.ASN1Encodable;
+import org.spongycastle.asn1.ASN1InputStream;
+import org.spongycastle.asn1.ASN1Integer;
+import org.spongycastle.asn1.ASN1ObjectIdentifier;
+import org.spongycastle.asn1.ASN1Primitive;
+import org.spongycastle.asn1.ASN1Sequence;
+import org.spongycastle.asn1.oiw.ElGamalParameter;
+import org.spongycastle.asn1.oiw.OIWObjectIdentifiers;
+import org.spongycastle.asn1.pkcs.DHParameter;
+import org.spongycastle.asn1.pkcs.PKCSObjectIdentifiers;
+import org.spongycastle.asn1.pkcs.PrivateKeyInfo;
+import org.spongycastle.asn1.pkcs.RSAPrivateKey;
+import org.spongycastle.asn1.sec.ECPrivateKey;
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.asn1.x509.DSAParameter;
+import org.spongycastle.asn1.x9.ECNamedCurveTable;
+import org.spongycastle.asn1.x9.X962Parameters;
+import org.spongycastle.asn1.x9.X9ECParameters;
+import org.spongycastle.asn1.x9.X9ObjectIdentifiers;
+import org.spongycastle.crypto.params.AsymmetricKeyParameter;
+import org.spongycastle.crypto.params.DHParameters;
+import org.spongycastle.crypto.params.DHPrivateKeyParameters;
+import org.spongycastle.crypto.params.DSAParameters;
+import org.spongycastle.crypto.params.DSAPrivateKeyParameters;
+import org.spongycastle.crypto.params.ECDomainParameters;
+import org.spongycastle.crypto.params.ECPrivateKeyParameters;
+import org.spongycastle.crypto.params.ElGamalParameters;
+import org.spongycastle.crypto.params.ElGamalPrivateKeyParameters;
+import org.spongycastle.crypto.params.RSAPrivateCrtKeyParameters;
+
+/**
+ * Factory for creating private key objects from PKCS8 PrivateKeyInfo objects.
+ */
+public class PrivateKeyFactory
+{
+    /**
+     * Create a private key parameter from a PKCS8 PrivateKeyInfo encoding.
+     * 
+     * @param privateKeyInfoData the PrivateKeyInfo encoding
+     * @return a suitable private key parameter
+     * @throws IOException on an error decoding the key
+     */
+    public static AsymmetricKeyParameter createKey(byte[] privateKeyInfoData) throws IOException
+    {
+        return createKey(PrivateKeyInfo.getInstance(ASN1Primitive.fromByteArray(privateKeyInfoData)));
+    }
+
+    /**
+     * Create a private key parameter from a PKCS8 PrivateKeyInfo encoding read from a
+     * stream.
+     * 
+     * @param inStr the stream to read the PrivateKeyInfo encoding from
+     * @return a suitable private key parameter
+     * @throws IOException on an error decoding the key
+     */
+    public static AsymmetricKeyParameter createKey(InputStream inStr) throws IOException
+    {
+        return createKey(PrivateKeyInfo.getInstance(new ASN1InputStream(inStr).readObject()));
+    }
+
+    /**
+     * Create a private key parameter from the passed in PKCS8 PrivateKeyInfo object.
+     * 
+     * @param keyInfo the PrivateKeyInfo object containing the key material
+     * @return a suitable private key parameter
+     * @throws IOException on an error decoding the key
+     */
+    public static AsymmetricKeyParameter createKey(PrivateKeyInfo keyInfo) throws IOException
+    {
+        AlgorithmIdentifier algId = keyInfo.getPrivateKeyAlgorithm();
+
+        if (algId.getAlgorithm().equals(PKCSObjectIdentifiers.rsaEncryption))
+        {
+            RSAPrivateKey keyStructure = RSAPrivateKey.getInstance(keyInfo.parsePrivateKey());
+
+            return new RSAPrivateCrtKeyParameters(keyStructure.getModulus(),
+                keyStructure.getPublicExponent(), keyStructure.getPrivateExponent(),
+                keyStructure.getPrime1(), keyStructure.getPrime2(), keyStructure.getExponent1(),
+                keyStructure.getExponent2(), keyStructure.getCoefficient());
+        }
+        // TODO?
+//      else if (algId.getObjectId().equals(X9ObjectIdentifiers.dhpublicnumber))
+        else if (algId.getAlgorithm().equals(PKCSObjectIdentifiers.dhKeyAgreement))
+        {
+            DHParameter params = DHParameter.getInstance(algId.getParameters());
+            ASN1Integer derX = (ASN1Integer)keyInfo.parsePrivateKey();
+
+            BigInteger lVal = params.getL();
+            int l = lVal == null ? 0 : lVal.intValue();
+            DHParameters dhParams = new DHParameters(params.getP(), params.getG(), null, l);
+
+            return new DHPrivateKeyParameters(derX.getValue(), dhParams);
+        }
+        else if (algId.getAlgorithm().equals(OIWObjectIdentifiers.elGamalAlgorithm))
+        {
+            ElGamalParameter params = new ElGamalParameter((ASN1Sequence)algId.getParameters());
+            ASN1Integer derX = (ASN1Integer)keyInfo.parsePrivateKey();
+
+            return new ElGamalPrivateKeyParameters(derX.getValue(), new ElGamalParameters(
+                params.getP(), params.getG()));
+        }
+        else if (algId.getAlgorithm().equals(X9ObjectIdentifiers.id_dsa))
+        {
+            ASN1Integer derX = (ASN1Integer)keyInfo.parsePrivateKey();
+            ASN1Encodable de = algId.getParameters();
+
+            DSAParameters parameters = null;
+            if (de != null)
+            {
+                DSAParameter params = DSAParameter.getInstance(de.toASN1Primitive());
+                parameters = new DSAParameters(params.getP(), params.getQ(), params.getG());
+            }
+
+            return new DSAPrivateKeyParameters(derX.getValue(), parameters);
+        }
+        else if (algId.getAlgorithm().equals(X9ObjectIdentifiers.id_ecPublicKey))
+        {
+            X962Parameters params = new X962Parameters((ASN1Primitive)algId.getParameters());
+
+            X9ECParameters x9;
+            if (params.isNamedCurve())
+            {
+                ASN1ObjectIdentifier oid = ASN1ObjectIdentifier.getInstance(params.getParameters());
+                x9 = ECNamedCurveTable.getByOID(oid);
+            }
+            else
+            {
+                x9 = X9ECParameters.getInstance(params.getParameters());
+            }
+
+            ECPrivateKey ec = ECPrivateKey.getInstance(keyInfo.parsePrivateKey());
+            BigInteger d = ec.getKey();
+
+            // TODO We lose any named parameters here
+
+            ECDomainParameters dParams = new ECDomainParameters(
+                    x9.getCurve(), x9.getG(), x9.getN(), x9.getH(), x9.getSeed());
+
+            return new ECPrivateKeyParameters(d, dParams);
+        }
+        else
+        {
+            throw new RuntimeException("algorithm identifier in key not recognised");
+        }
+    }
+}