org.bouncycastle.asn1.gm.GMNamedCurves Maven / Gradle / Ivy
package org.bouncycastle.asn1.gm;
import java.math.BigInteger;
import java.util.Enumeration;
import java.util.Hashtable;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.asn1.x9.X9ECParametersHolder;
import org.bouncycastle.asn1.x9.X9ECPoint;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.WNafUtil;
import org.bouncycastle.util.Strings;
import org.bouncycastle.util.encoders.Hex;
/**
* Chinese standard GM named curves.
*/
public class GMNamedCurves
{
private static X9ECPoint configureBasepoint(ECCurve curve, String encoding)
{
X9ECPoint G = new X9ECPoint(curve, Hex.decodeStrict(encoding));
WNafUtil.configureBasepoint(G.getPoint());
return G;
}
private static ECCurve configureCurve(ECCurve curve)
{
return curve;
}
private static BigInteger fromHex(String hex)
{
return new BigInteger(1, Hex.decodeStrict(hex));
}
/*
* SM2SysParams
*/
static X9ECParametersHolder sm2p256v1 = new X9ECParametersHolder()
{
protected X9ECParameters createParameters()
{
BigInteger p = fromHex("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF");
BigInteger a = fromHex("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC");
BigInteger b = fromHex("28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93");
byte[] S = null;
BigInteger n = fromHex("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123");
BigInteger h = BigInteger.valueOf(1);
ECCurve curve = configureCurve(new ECCurve.Fp(p, a, b, n, h));
X9ECPoint G = configureBasepoint(curve,
"0432C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE1715A4589334C74C7BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0");
return new X9ECParameters(curve, G, n, h, S);
}
};
static X9ECParametersHolder wapip192v1 = new X9ECParametersHolder()
{
protected X9ECParameters createParameters()
{
BigInteger p = fromHex("BDB6F4FE3E8B1D9E0DA8C0D46F4C318CEFE4AFE3B6B8551F");
BigInteger a = fromHex("BB8E5E8FBC115E139FE6A814FE48AAA6F0ADA1AA5DF91985");
BigInteger b = fromHex("1854BEBDC31B21B7AEFC80AB0ECD10D5B1B3308E6DBF11C1");
byte[] S = null;
BigInteger n = fromHex("BDB6F4FE3E8B1D9E0DA8C0D40FC962195DFAE76F56564677");
BigInteger h = BigInteger.valueOf(1);
ECCurve curve = configureCurve(new ECCurve.Fp(p, a, b, n, h));
X9ECPoint G = configureBasepoint(curve,
"044AD5F7048DE709AD51236DE65E4D4B482C836DC6E410664002BB3A02D4AAADACAE24817A4CA3A1B014B5270432DB27D2");
return new X9ECParameters(curve, G, n, h, S);
}
};
static final Hashtable objIds = new Hashtable();
static final Hashtable curves = new Hashtable();
static final Hashtable names = new Hashtable();
static void defineCurve(String name, ASN1ObjectIdentifier oid, X9ECParametersHolder holder)
{
objIds.put(Strings.toLowerCase(name), oid);
names.put(oid, name);
curves.put(oid, holder);
}
static
{
defineCurve("wapip192v1", GMObjectIdentifiers.wapip192v1, wapip192v1);
defineCurve("sm2p256v1", GMObjectIdentifiers.sm2p256v1, sm2p256v1);
}
public static X9ECParameters getByName(
String name)
{
ASN1ObjectIdentifier oid = getOID(name);
return oid == null ? null : getByOID(oid);
}
/**
* 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(
ASN1ObjectIdentifier oid)
{
X9ECParametersHolder holder = (X9ECParametersHolder)curves.get(oid);
return holder == null ? null : holder.getParameters();
}
/**
* 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 ASN1ObjectIdentifier getOID(
String name)
{
return (ASN1ObjectIdentifier)objIds.get(Strings.toLowerCase(name));
}
/**
* return the named curve name represented by the given object identifier.
*/
public static String getName(
ASN1ObjectIdentifier oid)
{
return (String)names.get(oid);
}
/**
* returns an enumeration containing the name strings for curves
* contained in this structure.
*/
public static Enumeration getNames()
{
return names.elements();
}
}