/*
* Copyright (c) 2006, 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.security.util;
import java.io.IOException;
import java.security.*;
import java.security.spec.*;
/**
* This class implements encoding and decoding of Elliptic Curve parameters
* as specified in RFC 3279.
*
* However, only named curves are currently supported.
*
* ASN.1 from RFC 3279 follows. Note that X9.62 (2005) has added some additional
* options.
*
* <pre>
* EcpkParameters ::= CHOICE {
* ecParameters ECParameters,
* namedCurve OBJECT IDENTIFIER,
* implicitlyCA NULL }
*
* ECParameters ::= SEQUENCE {
* version ECPVer, -- version is always 1
* fieldID FieldID, -- identifies the finite field over
* -- which the curve is defined
* curve Curve, -- coefficients a and b of the
* -- elliptic curve
* base ECPoint, -- specifies the base point P
* -- on the elliptic curve
* order INTEGER, -- the order n of the base point
* cofactor INTEGER OPTIONAL -- The integer h = #E(Fq)/n
* }
*
* ECPVer ::= INTEGER {ecpVer1(1)}
*
* Curve ::= SEQUENCE {
* a FieldElement,
* b FieldElement,
* seed BIT STRING OPTIONAL }
*
* FieldElement ::= OCTET STRING
*
* ECPoint ::= OCTET STRING
* </pre>
*
* @since 1.6
* @author Andreas Sterbenz
*/
public final class ECParameters extends AlgorithmParametersSpi {
// used by ECPublicKeyImpl and ECPrivateKeyImpl
public static AlgorithmParameters getAlgorithmParameters(ECParameterSpec spec)
throws InvalidKeyException {
try {
AlgorithmParameters params =
AlgorithmParameters.getInstance("EC", "SunEC");
params.init(spec);
return params;
} catch (GeneralSecurityException e) {
throw new InvalidKeyException("EC parameters error", e);
}
}
/*
* The parameters these AlgorithmParameters object represents.
* Currently, it is always an instance of NamedCurve.
*/
private NamedCurve namedCurve;
// A public constructor is required by AlgorithmParameters class.
public ECParameters() {
// empty
}
// AlgorithmParameterSpi methods
protected void engineInit(AlgorithmParameterSpec paramSpec)
throws InvalidParameterSpecException {
if (paramSpec == null) {
throw new InvalidParameterSpecException
("paramSpec must not be null");
}
if (paramSpec instanceof NamedCurve) {
namedCurve = (NamedCurve)paramSpec;
return;
}
if (paramSpec instanceof ECParameterSpec) {
namedCurve = CurveDB.lookup((ECParameterSpec)paramSpec);
} else if (paramSpec instanceof ECGenParameterSpec) {
String name = ((ECGenParameterSpec)paramSpec).getName();
namedCurve = CurveDB.lookup(name);
} else if (paramSpec instanceof ECKeySizeParameterSpec) {
int keySize = ((ECKeySizeParameterSpec)paramSpec).getKeySize();
namedCurve = CurveDB.lookup(keySize);
} else {
throw new InvalidParameterSpecException
("Only ECParameterSpec and ECGenParameterSpec supported");
}
if (namedCurve == null) {
throw new InvalidParameterSpecException(
"Not a supported curve: " + paramSpec);
}
}
protected void engineInit(byte[] params) throws IOException {
DerValue encodedParams = new DerValue(params);
if (encodedParams.tag == DerValue.tag_ObjectId) {
ObjectIdentifier oid = encodedParams.getOID();
NamedCurve spec = CurveDB.lookup(oid.toString());
if (spec == null) {
throw new IOException("Unknown named curve: " + oid);
}
namedCurve = spec;
return;
}
throw new IOException("Only named ECParameters supported");
// The code below is incomplete.
// It is left as a starting point for a complete parsing implementation.
/*
if (encodedParams.tag != DerValue.tag_Sequence) {
throw new IOException("Unsupported EC parameters, tag: " +
encodedParams.tag);
}
encodedParams.data.reset();
DerInputStream in = encodedParams.data;
int version = in.getInteger();
if (version != 1) {
throw new IOException("Unsupported EC parameters version: " +
version);
}
ECField field = parseField(in);
EllipticCurve curve = parseCurve(in, field);
ECPoint point = parsePoint(in, curve);
BigInteger order = in.getBigInteger();
int cofactor = 0;
if (in.available() != 0) {
cofactor = in.getInteger();
}
// XXX HashAlgorithm optional
if (encodedParams.data.available() != 0) {
throw new IOException("encoded params have " +
encodedParams.data.available() +
" extra bytes");
}
return new ECParameterSpec(curve, point, order, cofactor);
*/
}
protected void engineInit(byte[] params, String decodingMethod)
throws IOException {
engineInit(params);
}
protected <T extends AlgorithmParameterSpec> T
engineGetParameterSpec(Class<T> spec)
throws InvalidParameterSpecException {
if (spec.isAssignableFrom(ECParameterSpec.class)) {
return spec.cast(namedCurve);
}
if (spec.isAssignableFrom(ECGenParameterSpec.class)) {
// Ensure the name is the Object ID
String name = namedCurve.getObjectId();
return spec.cast(new ECGenParameterSpec(name));
}
if (spec.isAssignableFrom(ECKeySizeParameterSpec.class)) {
int keySize = namedCurve.getCurve().getField().getFieldSize();
return spec.cast(new ECKeySizeParameterSpec(keySize));
}
throw new InvalidParameterSpecException(
"Only ECParameterSpec and ECGenParameterSpec supported");
}
protected byte[] engineGetEncoded() throws IOException {
return namedCurve.getEncoded();
}
protected byte[] engineGetEncoded(String encodingMethod)
throws IOException {
return engineGetEncoded();
}
protected String engineToString() {
if (namedCurve == null) {
return "Not initialized";
}
return namedCurve.toString();
}
}