1 files changed, 154 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/asn1/ua/DSTU4145ECBinary.java b/core/src/main/java/org/spongycastle/asn1/ua/DSTU4145ECBinary.java
new file mode 100644
index 00000000..bd2d9add
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/asn1/ua/DSTU4145ECBinary.java
@@ -0,0 +1,154 @@
+package org.spongycastle.asn1.ua;
+
+import java.math.BigInteger;
+
+import org.spongycastle.asn1.ASN1EncodableVector;
+import org.spongycastle.asn1.ASN1Integer;
+import org.spongycastle.asn1.ASN1Object;
+import org.spongycastle.asn1.ASN1OctetString;
+import org.spongycastle.asn1.ASN1Primitive;
+import org.spongycastle.asn1.ASN1Sequence;
+import org.spongycastle.asn1.ASN1TaggedObject;
+import org.spongycastle.asn1.DEROctetString;
+import org.spongycastle.asn1.DERSequence;
+import org.spongycastle.asn1.DERTaggedObject;
+import org.spongycastle.crypto.params.ECDomainParameters;
+import org.spongycastle.math.ec.ECAlgorithms;
+import org.spongycastle.math.ec.ECCurve;
+import org.spongycastle.math.field.PolynomialExtensionField;
+import org.spongycastle.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);
+    }
+
+}