com.kixeye.chassis.transport.websocket.WebSocketPskFrameProcessor.java Source code

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Here is the source code for com.kixeye.chassis.transport.websocket.WebSocketPskFrameProcessor.java

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package com.kixeye.chassis.transport.websocket;

/*
 * #%L
 * Chassis Transport Core
 * %%
 * Copyright (C) 2014 KIXEYE, Inc
 * %%
 * 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.
 * #L%
 */

import java.security.GeneralSecurityException;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Component;

import com.google.common.io.BaseEncoding;
import com.kixeye.chassis.transport.crypto.SymmetricKeyCipher;

/**
 * Processes a websocket frame with PSK encryption if encryption is enabled.
 * 
 * @author ebahtijaragic
 */
@Component
public class WebSocketPskFrameProcessor {
    private static final DefaultResourceLoader RESOURCE_LOADER = new DefaultResourceLoader();

    private final SymmetricKeyCipher cipher;

    /**
     * @param cipherProvider
     * @param cipherTransformation
     * @param secretKeyProvider
     * @param secretKeyAlgorithm
     * @param secretKeyData
     * @param secretKeyPath
     * @param enabled
     * @param secretKey
     */
    @Autowired
    public WebSocketPskFrameProcessor(@Value("${websocket.crypto.cipherProvider:}") String cipherProvider,
            @Value("${websocket.crypto.cipherTransformation:}") String cipherTransformation,
            @Value("${websocket.crypto.secretKeyAlgorithm:}") String secretKeyAlgorithm,
            @Value("${websocket.crypto.secretKeyData:}") String secretKeyData,
            @Value("${websocket.crypto.secretKeyPath:}") String secretKeyPath,
            @Value("${websocket.crypto.enabled:false}") boolean enabled) throws Exception {
        if (enabled) {
            byte[] secretKey = null;

            if (StringUtils.isNoneBlank(secretKeyData)) {
                secretKey = BaseEncoding.base16().decode(secretKeyData);
            } else if (StringUtils.isNoneBlank(secretKeyPath)) {
                Resource secretKeyFile = RESOURCE_LOADER.getResource(secretKeyPath);

                secretKey = IOUtils.toByteArray(secretKeyFile.getInputStream());
            } else {
                throw new IllegalArgumentException("Neither secret key data nor path were provided.");
            }

            cipher = new SymmetricKeyCipher(cipherProvider, cipherTransformation, secretKeyAlgorithm, secretKey);
        } else {
            cipher = null;
        }
    }

    /**
     * Processes an incoming frame.
     * 
     * @param payload
     * @return
     * @throws GeneralSecurityException
     */
    public byte[] processIncoming(byte[] payload, int offset, int length) throws GeneralSecurityException {
        if (cipher != null) {
            return cipher.decrypt(payload, offset, length);
        } else {
            return payload;
        }
    }

    /**
     * Processes an outgoing frame.
     * 
     * @param payload
     * @return
     * @throws GeneralSecurityException
     */
    public byte[] processOutgoing(byte[] payload, int offset, int length) throws GeneralSecurityException {
        if (cipher != null) {
            return cipher.encrypt(payload, offset, length);
        } else {
            return payload;
        }
    }
}