package org.bouncycastle.asn1.x9; import java.math.BigInteger; import org.bouncycastle.asn1.ASN1OctetString; import org.bouncycastle.asn1.DEREncodable; import org.bouncycastle.asn1.DERObject; import org.bouncycastle.asn1.DEROctetString; import org.bouncycastle.math.ec.ECFieldElement; /** * class for processing an FieldElement as a DER object. */ public class X9FieldElement implements DEREncodable { private ECFieldElement f; public X9FieldElement( ECFieldElement f) { this.f = f; } public X9FieldElement( boolean fP, BigInteger q, ASN1OctetString s) { if (fP) { this.f = new ECFieldElement.Fp(q, new BigInteger(1, s.getOctets())); } else { throw new RuntimeException("not implemented"); } } public ECFieldElement getValue() { return f; } /** * Produce an object suitable for an ASN1OutputStream. * <pre> * FieldElement ::= OCTET STRING * </pre> * <p> * <ol> * <li> if <i>q</i> is an odd prime then the field element is * processed as an Integer and converted to an octet string * according to x 9.62 4.3.1.</li> * <li> if <i>q</i> is 2<sup>m</sup> then the bit string * contained in the field element is converted into an octet * string with the same ordering padded at the front if necessary. * </li> * </ol> */ public DERObject getDERObject() { return new DEROctetString(f.toBigInteger().toByteArray()); } }