ro.esolutions.licensing.DataSignatureManager Maven / Gradle / Ivy

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/*
 * DataSignatureManager.java from LicenseManager modified Tuesday, February 21, 2012 10:59:35 CST (-0600).
 *
 * Copyright 2010-2013 the original author or authors.
 *
 * 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 ro.esolutions.licensing;

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.SignatureException;

import ro.esolutions.licensing.encryption.KeyFileUtilities;
import ro.esolutions.licensing.exception.AlgorithmNotSupportedException;
import ro.esolutions.licensing.exception.CorruptSignatureException;
import ro.esolutions.licensing.exception.InappropriateKeyException;
import ro.esolutions.licensing.exception.InvalidSignatureException;

public final class DataSignatureManager {
    public final byte[] signData(final PrivateKey key, final byte[] data) throws AlgorithmNotSupportedException,
            InappropriateKeyException {

        final Signature signature = this.getSignature();

        try {
            signature.initSign(key);
        } catch (final InvalidKeyException e) {
            throw new InappropriateKeyException("While initializing the signature object with the public key.", e);
        }

        try {
            signature.update(data);
        } catch (final SignatureException e) {
            throw new RuntimeException("This should never happen.", e);
        }

        try {
            return signature.sign();
        } catch (final SignatureException e) {
            throw new RuntimeException("This should never happen.", e);
        }
    }

    public final void verifySignature(final PublicKey key, final byte[] data, final byte[] signatureContent)
            throws AlgorithmNotSupportedException, InappropriateKeyException, CorruptSignatureException, InvalidSignatureException {

        final Signature signature = this.getSignature();

        try {
            signature.initVerify(key);
        } catch (final InvalidKeyException e) {
            throw new InappropriateKeyException("While initializing the signature object with the public key.", e);
        }

        try {
            signature.update(data);
        } catch (final SignatureException e) {
            throw new RuntimeException("This should never happen.", e);
        }

        try {
            if (!signature.verify(signatureContent))
                throw new InvalidSignatureException("The license signature is invalid.");
        } catch (final SignatureException e) {
            throw new CorruptSignatureException("While verifying the signature.", e);
        }
    }

    private Signature getSignature() {
        try {
            return Signature.getInstance("SHA1with" + KeyFileUtilities.KEY_ALGORITHM);
        } catch (final NoSuchAlgorithmException e) {
            throw new AlgorithmNotSupportedException("SHA-1 with " + KeyFileUtilities.KEY_ALGORITHM);
        }
    }
}