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package org.bouncycastle.asn1.ua;
import java.math.BigInteger;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Integer;
import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERTaggedObject;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.math.ec.ECAlgorithms;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.field.PolynomialExtensionField;
import org.bouncycastle.util.Arrays;
public class DSTU4145ECBinary
extends ASN1Object
{
BigInteger version = BigInteger.valueOf(0);
DSTU4145BinaryField f;
ASN1Integer a;
ASN1OctetString b;
ASN1Integer n;
ASN1OctetString bp;
public DSTU4145ECBinary(ECDomainParameters params)
{
ECCurve curve = params.getCurve();
if (!ECAlgorithms.isF2mCurve(curve))
{
throw new IllegalArgumentException("only binary domain is possible");
}
// We always use big-endian in parameter encoding
PolynomialExtensionField field = (PolynomialExtensionField)curve.getField();
int[] exponents = field.getMinimalPolynomial().getExponentsPresent();
if (exponents.length == 3)
{
f = new DSTU4145BinaryField(exponents[2], exponents[1]);
}
else if (exponents.length == 5)
{
f = new DSTU4145BinaryField(exponents[4], exponents[1], exponents[2], exponents[3]);
}
a = new ASN1Integer(curve.getA().toBigInteger());
b = new DEROctetString(curve.getB().getEncoded());
n = new ASN1Integer(params.getN());
bp = new DEROctetString(DSTU4145PointEncoder.encodePoint(params.getG()));
}
private DSTU4145ECBinary(ASN1Sequence seq)
{
int index = 0;
if (seq.getObjectAt(index) instanceof ASN1TaggedObject)
{
ASN1TaggedObject taggedVersion = (ASN1TaggedObject)seq.getObjectAt(index);
if (taggedVersion.isExplicit() && 0 == taggedVersion.getTagNo())
{
version = ASN1Integer.getInstance(taggedVersion.getLoadedObject()).getValue();
index++;
}
else
{
throw new IllegalArgumentException("object parse error");
}
}
f = DSTU4145BinaryField.getInstance(seq.getObjectAt(index));
index++;
a = ASN1Integer.getInstance(seq.getObjectAt(index));
index++;
b = ASN1OctetString.getInstance(seq.getObjectAt(index));
index++;
n = ASN1Integer.getInstance(seq.getObjectAt(index));
index++;
bp = ASN1OctetString.getInstance(seq.getObjectAt(index));
}
public static DSTU4145ECBinary getInstance(Object obj)
{
if (obj instanceof DSTU4145ECBinary)
{
return (DSTU4145ECBinary)obj;
}
if (obj != null)
{
return new DSTU4145ECBinary(ASN1Sequence.getInstance(obj));
}
return null;
}
public DSTU4145BinaryField getField()
{
return f;
}
public BigInteger getA()
{
return a.getValue();
}
public byte[] getB()
{
return Arrays.clone(b.getOctets());
}
public BigInteger getN()
{
return n.getValue();
}
public byte[] getG()
{
return Arrays.clone(bp.getOctets());
}
/**
* ECBinary ::= SEQUENCE {
* version [0] EXPLICIT INTEGER DEFAULT 0,
* f BinaryField,
* a INTEGER (0..1),
* b OCTET STRING,
* n INTEGER,
* bp OCTET STRING}
*/
public ASN1Primitive toASN1Primitive()
{
ASN1EncodableVector v = new ASN1EncodableVector();
if (0 != version.compareTo(BigInteger.valueOf(0)))
{
v.add(new DERTaggedObject(true, 0, new ASN1Integer(version)));
}
v.add(f);
v.add(a);
v.add(b);
v.add(n);
v.add(bp);
return new DERSequence(v);
}
}
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