AndroidHttpClient.java

/*
 * Copyright 2014-2016 CyberVision, 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.
 */

package org.kaaproject.kaa.client.transport;

import org.apache.commons.io.Charsets;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.ByteArrayBuffer;
import org.kaaproject.kaa.common.endpoint.CommonEpConstans;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.util.LinkedHashMap;

public class AndroidHttpClient extends AbstractHttpClient {

  /**
   * The Constant LOG.
   */
  public static final Logger LOG = LoggerFactory // NOSONAR
      .getLogger(AndroidHttpClient.class);

  private DefaultHttpClient httpClient;
  private volatile HttpPost method;

  /**
   * Instantiates a new AndroidHttpClient.
   */
  public AndroidHttpClient(String url, PrivateKey privateKey,
                           PublicKey publicKey, PublicKey remotePublicKey) {
    super(url, privateKey, publicKey, remotePublicKey);
    this.httpClient = new DefaultHttpClient();
    this.method = null;
  }

  private static byte[] toByteArray(final HttpEntity entity) throws IOException {
    if (entity == null) {
      throw new IllegalArgumentException("HTTP entity may not be null");
    }
    InputStream instream = entity.getContent();
    if (instream == null) {
      return new byte[]{};
    }
    if (entity.getContentLength() > Integer.MAX_VALUE) {
      throw new IllegalArgumentException("HTTP entity too large to be buffered in memory");
    }
    int count = (int) entity.getContentLength();
    if (count < 0) {
      count = 4096;
    }
    ByteArrayBuffer buffer = new ByteArrayBuffer(count);
    try {
      byte[] tmp = new byte[4096];
      int len;
      while ((len = instream.read(tmp)) != -1) {
        buffer.append(tmp, 0, len);
      }
    } finally {
      instream.close();
    }
    return buffer.toByteArray();
  }

  private static void consume(final HttpEntity entity) throws IOException {
    if (entity == null) {
      return;
    }
    if (entity.isStreaming()) {
      final InputStream instream = entity.getContent();
      if (instream != null) {
        instream.close();
      }
    }
  }

  @Override
  public byte[] executeHttpRequest(String uri, LinkedHashMap<String, byte[]> entity,
                                   boolean verifyResponse) throws Exception { //NOSONAR

    byte[] responseDataRaw = null;
    method = new HttpPost(url + uri);
    MultipartEntity requestEntity = new MultipartEntity();
    for (String key : entity.keySet()) {
      requestEntity.addPart(key, new ByteArrayBody(entity.get(key), null));
    }
    method.setEntity(requestEntity);
    if (!Thread.currentThread().isInterrupted()) {
      LOG.debug("Executing request {}", method.getRequestLine());
      HttpResponse response = httpClient.execute(method);
      try {
        LOG.debug("Received {}", response.getStatusLine());
        int status = response.getStatusLine().getStatusCode();
        if (status >= 200 && status < 300) {
          responseDataRaw = getResponseBody(response, verifyResponse);
        } else {
          throw new TransportException(status);
        }
      } finally {
        method = null;
      }
    } else {
      method = null;
      throw new InterruptedException();
    }
    return responseDataRaw;
  }

  private byte[] getResponseBody(HttpResponse response, boolean verifyResponse) throws IOException,
      GeneralSecurityException {

    HttpEntity resEntity = response.getEntity();
    if (resEntity != null) {
      byte[] body = toByteArray(resEntity);
      consume(resEntity);

      if (verifyResponse) {
        Header signatureHeader = response
            .getFirstHeader(CommonEpConstans.SIGNATURE_HEADER_NAME);

        if (signatureHeader == null) {
          throw new IOException("can't verify message");
        }

        byte[] signature;
        if (signatureHeader.getValue() != null) {
          signature = android.util.Base64.decode(signatureHeader.getValue()
              .getBytes(Charsets.UTF_8), android.util.Base64.DEFAULT);
        } else {
          signature = new byte[0];
        }

        // LOG.debug("Remote Public Key: {}" +
        // messageEncDec.getRemotePublicKey().getEncoded().length);
        // LOG.debug(MessageEncoderDecoder.bytesToHex(messageEncDec.getRemotePublicKey()
        // .getEncoded()));
        // LOG.debug("Signature size: {}" + signature.length);
        // LOG.debug(MessageEncoderDecoder.bytesToHex(signature));
        // LOG.debug("Body size: {}" + body.length);
        // LOG.debug(MessageEncoderDecoder.bytesToHex(body));

        return verifyResponse(body, signature);
      } else {
        return body;
      }
    } else {
      throw new IOException("can't read message");
    }
  }

  @Override
  public void close() throws IOException {
    abort();
    method = null;
    httpClient = null;
  }

  @Override
  public void abort() {
    if (method != null && !method.isAborted()) {
      LOG.info("Forcely aborting current request...");
      method.abort();
    }
  }

  @Override
  public boolean canAbort() {
    return method != null && !method.isAborted();
  }

}