io.jsonwebtoken.impl.crypto.EllipticCurveSignatureValidator Maven / Gradle / Ivy
/*
* Copyright (C) 2015 jsonwebtoken.io
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.jsonwebtoken.impl.crypto;
import io.jsonwebtoken.SignatureAlgorithm;
import io.jsonwebtoken.lang.Assert;
import io.jsonwebtoken.security.SignatureException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.ECPublicKey;
public class EllipticCurveSignatureValidator extends EllipticCurveProvider implements SignatureValidator {
private static final String EC_PUBLIC_KEY_REQD_MSG =
"Elliptic Curve signature validation requires an ECPublicKey instance.";
public EllipticCurveSignatureValidator(SignatureAlgorithm alg, Key key) {
super(alg, key);
Assert.isTrue(key instanceof ECPublicKey, EC_PUBLIC_KEY_REQD_MSG);
}
@Override
public boolean isValid(byte[] data, byte[] signature) {
Signature sig = createSignatureInstance();
PublicKey publicKey = (PublicKey) key;
try {
int expectedSize = getSignatureByteArrayLength(alg);
/**
*
* If the expected size is not valid for JOSE, fall back to ASN.1 DER signature.
* This fallback is for backwards compatibility ONLY (to support tokens generated by previous versions of jjwt)
* and backwards compatibility will possibly be removed in a future version of this library.
*
* **/
byte[] derSignature = expectedSize != signature.length && signature[0] == 0x30 ? signature : EllipticCurveProvider.transcodeSignatureToDER(signature);
return doVerify(sig, publicKey, data, derSignature);
} catch (Exception e) {
String msg = "Unable to verify Elliptic Curve signature using configured ECPublicKey. " + e.getMessage();
throw new SignatureException(msg, e);
}
}
protected boolean doVerify(Signature sig, PublicKey publicKey, byte[] data, byte[] signature)
throws InvalidKeyException, java.security.SignatureException {
sig.initVerify(publicKey);
sig.update(data);
return sig.verify(signature);
}
}