package org.bouncycastle.asn1.nist;
import org.bouncycastle.asn1.DERObjectIdentifier;
import org.bouncycastle.asn1.sec.SECNamedCurves;
import org.bouncycastle.asn1.sec.SECObjectIdentifiers;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.util.Strings;
import java.util.Enumeration;
import java.util.Hashtable;
/**
* Utility class for fetching curves using their NIST names as published in FIPS-PUB 186-2
*/
public class NISTNamedCurves
{
static final Hashtable<String, DERObjectIdentifier> objIds = new Hashtable<String, DERObjectIdentifier>();
static final Hashtable<DERObjectIdentifier, String> names = new Hashtable<DERObjectIdentifier, String>();
static void defineCurve(String name, DERObjectIdentifier oid)
{
objIds.put(name, oid);
names.put(oid, name);
}
static
{
// TODO Missing the "K-" curves
defineCurve("B-571", SECObjectIdentifiers.sect571r1);
defineCurve("B-409", SECObjectIdentifiers.sect409r1);
defineCurve("B-283", SECObjectIdentifiers.sect283r1);
defineCurve("B-233", SECObjectIdentifiers.sect233r1);
defineCurve("B-163", SECObjectIdentifiers.sect163r2);
defineCurve("P-521", SECObjectIdentifiers.secp521r1);
defineCurve("P-384", SECObjectIdentifiers.secp384r1);
defineCurve("P-256", SECObjectIdentifiers.secp256r1);
defineCurve("P-224", SECObjectIdentifiers.secp224r1);
defineCurve("P-192", SECObjectIdentifiers.secp192r1);
}
public static X9ECParameters getByName(
String name)
{
DERObjectIdentifier oid = objIds.get(Strings.toUpperCase(name));
if (oid != null)
{
return getByOID(oid);
}
return null;
}
/**
* return the X9ECParameters object for the named curve represented by
* the passed in object identifier. Null if the curve isn't present.
*
* @param oid an object identifier representing a named curve, if present.
*/
public static X9ECParameters getByOID(
DERObjectIdentifier oid)
{
return SECNamedCurves.getByOID(oid);
}
/**
* return the object identifier signified by the passed in name. Null
* if there is no object identifier associated with name.
*
* @return the object identifier associated with name, if present.
*/
public static DERObjectIdentifier getOID(
String name)
{
return objIds.get(Strings.toUpperCase(name));
}
/**
* return the named curve name represented by the given object identifier.
*/
public static String getName(
DERObjectIdentifier oid)
{
return names.get(oid);
}
/**
* returns an enumeration containing the name strings for curves
* contained in this structure.
*/
public static Enumeration<String> getNames()
{
return objIds.keys();
}
}