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The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.6.
package org.bouncycastle.jce.provider.asymmetric.ec;
import org.bouncycastle.asn1.DERObjectIdentifier;
import org.bouncycastle.asn1.cryptopro.ECGOST3410NamedCurves;
import org.bouncycastle.asn1.nist.NISTNamedCurves;
import org.bouncycastle.asn1.sec.SECNamedCurves;
import org.bouncycastle.asn1.teletrust.TeleTrusTNamedCurves;
import org.bouncycastle.asn1.x9.X962NamedCurves;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.jce.interfaces.ECPrivateKey;
import org.bouncycastle.jce.interfaces.ECPublicKey;
import org.bouncycastle.jce.spec.ECParameterSpec;
import org.bouncycastle.jce.provider.ProviderUtil;
import org.bouncycastle.jce.provider.JCEECPublicKey;
import java.security.InvalidKeyException;
import java.security.PrivateKey;
import java.security.PublicKey;
/**
* utility class for converting jce/jca ECDSA, ECDH, and ECDHC
* objects into their org.bouncycastle.crypto counterparts.
*/
public class ECUtil
{
/**
* Returns a sorted array of middle terms of the reduction polynomial.
* @param k The unsorted array of middle terms of the reduction polynomial
* of length 1 or 3.
* @return the sorted array of middle terms of the reduction polynomial.
* This array always has length 3.
*/
static int[] convertMidTerms(
int[] k)
{
int[] res = new int[3];
if (k.length == 1)
{
res[0] = k[0];
}
else
{
if (k.length != 3)
{
throw new IllegalArgumentException("Only Trinomials and pentanomials supported");
}
if (k[0] < k[1] && k[0] < k[2])
{
res[0] = k[0];
if (k[1] < k[2])
{
res[1] = k[1];
res[2] = k[2];
}
else
{
res[1] = k[2];
res[2] = k[1];
}
}
else if (k[1] < k[2])
{
res[0] = k[1];
if (k[0] < k[2])
{
res[1] = k[0];
res[2] = k[2];
}
else
{
res[1] = k[2];
res[2] = k[0];
}
}
else
{
res[0] = k[2];
if (k[0] < k[1])
{
res[1] = k[0];
res[2] = k[1];
}
else
{
res[1] = k[1];
res[2] = k[0];
}
}
}
return res;
}
public static AsymmetricKeyParameter generatePublicKeyParameter(
PublicKey key)
throws InvalidKeyException
{
if (key instanceof ECPublicKey)
{
ECPublicKey k = (ECPublicKey)key;
ECParameterSpec s = k.getParameters();
if (s == null)
{
s = ProviderUtil.getEcImplicitlyCa();
return new ECPublicKeyParameters(
((JCEECPublicKey)k).engineGetQ(),
new ECDomainParameters(s.getCurve(), s.getG(), s.getN(), s.getH(), s.getSeed()));
}
else
{
return new ECPublicKeyParameters(
k.getQ(),
new ECDomainParameters(s.getCurve(), s.getG(), s.getN(), s.getH(), s.getSeed()));
}
}
else if (key instanceof java.security.interfaces.ECPublicKey)
{
java.security.interfaces.ECPublicKey pubKey = (java.security.interfaces.ECPublicKey)key;
ECParameterSpec s = EC5Util.convertSpec(pubKey.getParams(), false);
return new ECPublicKeyParameters(
EC5Util.convertPoint(pubKey.getParams(), pubKey.getW(), false),
new ECDomainParameters(s.getCurve(), s.getG(), s.getN(), s.getH(), s.getSeed()));
}
throw new InvalidKeyException("cannot identify EC public key.");
}
public static AsymmetricKeyParameter generatePrivateKeyParameter(
PrivateKey key)
throws InvalidKeyException
{
if (key instanceof ECPrivateKey)
{
ECPrivateKey k = (ECPrivateKey)key;
ECParameterSpec s = k.getParameters();
if (s == null)
{
s = ProviderUtil.getEcImplicitlyCa();
}
return new ECPrivateKeyParameters(
k.getD(),
new ECDomainParameters(s.getCurve(), s.getG(), s.getN(), s.getH(), s.getSeed()));
}
throw new InvalidKeyException("can't identify EC private key.");
}
public static DERObjectIdentifier getNamedCurveOid(
String name)
{
DERObjectIdentifier oid = X962NamedCurves.getOID(name);
if (oid == null)
{
oid = SECNamedCurves.getOID(name);
if (oid == null)
{
oid = NISTNamedCurves.getOID(name);
}
if (oid == null)
{
oid = TeleTrusTNamedCurves.getOID(name);
}
if (oid == null)
{
oid = ECGOST3410NamedCurves.getOID(name);
}
}
return oid;
}
public static X9ECParameters getNamedCurveByOid(
DERObjectIdentifier oid)
{
X9ECParameters params = X962NamedCurves.getByOID(oid);
if (params == null)
{
params = SECNamedCurves.getByOID(oid);
if (params == null)
{
params = NISTNamedCurves.getByOID(oid);
}
if (params == null)
{
params = TeleTrusTNamedCurves.getByOID(oid);
}
}
return params;
}
public static String getCurveName(
DERObjectIdentifier oid)
{
String name = X962NamedCurves.getName(oid);
if (name == null)
{
name = SECNamedCurves.getName(oid);
if (name == null)
{
name = NISTNamedCurves.getName(oid);
}
if (name == null)
{
name = TeleTrusTNamedCurves.getName(oid);
}
if (name == null)
{
name = ECGOST3410NamedCurves.getName(oid);
}
}
return name;
}
}