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/*
* This file is part of dependency-check-utils.
*
* 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.
*
* Copyright (c) 2018 Jeremy Long. All Rights Reserved.
*/
package org.owasp.dependencycheck.utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import static java.lang.String.format;
import java.net.HttpURLConnection;
import java.net.URISyntaxException;
import java.net.URL;
import java.security.InvalidAlgorithmParameterException;
import java.util.zip.GZIPInputStream;
import java.util.zip.InflaterInputStream;
/**
* A utility to download files from the Internet.
*
* @author Jeremy Long
* @version $Id: $Id
*/
public class HttpResourceConnection implements AutoCloseable {
/**
* The logger.
*/
private static final Logger LOGGER = LoggerFactory.getLogger(HttpResourceConnection.class);
/**
* The maximum number of redirects that will be followed when attempting to
* download a file.
*/
private static final int MAX_REDIRECT_ATTEMPTS = 5;
/**
* The default HTTP request method for query timestamp
*/
private static final String HEAD = "HEAD";
/**
* The HTTP request method which can be used by query timestamp
*/
private static final String GET = "GET";
/**
* The configured settings.
*/
private final Settings settings;
/**
* The URL conn factory.
*/
private final URLConnectionFactory connFactory;
/**
* The current conn.
*/
private HttpURLConnection connection = null;
/**
* Whether or not the conn will use the defined proxy.
*/
private boolean usesProxy;
/**
* Constructs a new HttpResourceConnection object.
*
* @param settings the configured settings
*/
public HttpResourceConnection(Settings settings) {
this(settings, true);
}
/**
* Constructs a new HttpResourceConnection object.
*
* @param settings the configured settings
* @param usesProxy control whether this conn will use the defined proxy.
*/
public HttpResourceConnection(Settings settings, boolean usesProxy) {
this.settings = settings;
this.connFactory = new URLConnectionFactory(settings);
this.usesProxy = usesProxy;
}
/**
* Retrieves the resource identified by the given URL and returns the
* InputStream.
*
* @param url the URL of the resource to download
* @return the stream to read the retrieved content from
* @throws org.owasp.dependencycheck.utils.DownloadFailedException is thrown
* if there is an error downloading the resource
* @throws TooManyRequestsException thrown when a 429 is received
* @throws ResourceNotFoundException thrown when a 404 is received
*/
public InputStream fetch(URL url) throws DownloadFailedException, TooManyRequestsException, ResourceNotFoundException {
if ("file".equalsIgnoreCase(url.getProtocol())) {
final File file;
try {
file = new File(url.toURI());
} catch (URISyntaxException ex) {
final String msg = format("Download failed, unable to locate '%s'", url.toString());
throw new DownloadFailedException(msg);
}
if (file.exists()) {
try {
return new FileInputStream(file);
} catch (IOException ex) {
final String msg = format("Download failed, unable to rerieve '%s'", url.toString());
throw new DownloadFailedException(msg, ex);
}
} else {
final String msg = format("Download failed, file ('%s') does not exist", url.toString());
throw new DownloadFailedException(msg);
}
} else {
if (connection != null) {
LOGGER.warn("HTTP URL Connection was not properly closed");
connection.disconnect();
connection = null;
}
connection = obtainConnection(url);
final String encoding = connection.getContentEncoding();
try {
if (encoding != null && "gzip".equalsIgnoreCase(encoding)) {
return new GZIPInputStream(connection.getInputStream());
} else if (encoding != null && "deflate".equalsIgnoreCase(encoding)) {
return new InflaterInputStream(connection.getInputStream());
} else {
return connection.getInputStream();
}
} catch (IOException ex) {
checkForCommonExceptionTypes(ex);
final String msg = format("Error retrieving '%s'%nConnection Timeout: %d%nEncoding: %s%n",
url.toString(), connection.getConnectTimeout(), encoding);
throw new DownloadFailedException(msg, ex);
} catch (Exception ex) {
final String msg = format("Unexpected exception retrieving '%s'%nConnection Timeout: %d%nEncoding: %s%n",
url.toString(), connection.getConnectTimeout(), encoding);
throw new DownloadFailedException(msg, ex);
}
}
}
/**
* Obtains the HTTP URL Connection.
*
* @param url the URL
* @return the HTTP URL Connection
* @throws DownloadFailedException thrown if there is an error creating the
* HTTP URL Connection
* @throws TooManyRequestsException thrown when a 429 is received
* @throws ResourceNotFoundException thrown when a 404 is received
*/
private HttpURLConnection obtainConnection(URL url) throws DownloadFailedException, TooManyRequestsException, ResourceNotFoundException {
HttpURLConnection conn = null;
try {
LOGGER.debug("Attempting retrieval of {}", url.toString());
conn = connFactory.createHttpURLConnection(url, this.usesProxy);
conn.setRequestProperty("Accept-Encoding", "gzip, deflate");
conn.connect();
int status = conn.getResponseCode();
int redirectCount = 0;
// TODO - should this get replaced by using the conn.setInstanceFollowRedirects(true);
while ((status == HttpURLConnection.HTTP_MOVED_TEMP
|| status == HttpURLConnection.HTTP_MOVED_PERM
|| status == HttpURLConnection.HTTP_SEE_OTHER)
&& MAX_REDIRECT_ATTEMPTS > redirectCount++) {
final String location = conn.getHeaderField("Location");
try {
conn.disconnect();
} finally {
conn = null;
}
LOGGER.debug("Download is being redirected from {} to {}", url.toString(), location);
conn = connFactory.createHttpURLConnection(new URL(location), this.usesProxy);
conn.setRequestProperty("Accept-Encoding", "gzip, deflate");
conn.connect();
status = conn.getResponseCode();
}
if (status == 404) {
try {
conn.disconnect();
} finally {
conn = null;
}
throw new ResourceNotFoundException("Requested resource does not exists - received a 404");
} else if (status == 429) {
try {
conn.disconnect();
} finally {
conn = null;
}
throw new TooManyRequestsException("Download fialed - too many connection requests");
} else if (status != 200) {
try {
conn.disconnect();
} finally {
conn = null;
}
final String msg = format("Error retrieving %s; received response code %s.", url.toString(), status);
LOGGER.error(msg);
throw new DownloadFailedException(msg);
}
} catch (IOException ex) {
try {
if (conn != null) {
conn.disconnect();
}
} finally {
conn = null;
}
if ("Connection reset".equalsIgnoreCase(ex.getMessage())) {
final String msg = format("TLS Connection Reset%nPlease see "
+ "http://jeremylong.github.io/DependencyCheck/data/tlsfailure.html "
+ "for more information regarding how to resolve the issue.");
LOGGER.error(msg);
throw new DownloadFailedException(msg, ex);
}
final String msg = format("Error downloading file %s; unable to connect.", url.toString());
throw new DownloadFailedException(msg, ex);
}
return conn;
}
/**
* Makes an HTTP Head request to retrieve the last modified date of the
* given URL. If the file:// protocol is specified, then the lastTimestamp
* of the file is returned.
*
* @param url the URL to retrieve the timestamp from
* @return an epoch timestamp
* @throws org.owasp.dependencycheck.utils.DownloadFailedException is thrown
* if an exception occurs making the HTTP request
* @deprecated this method is no longer used to check the last modified date
* of the NVD. This method will be removed in a future release.
*/
@Deprecated
public long getLastModified(URL url) throws DownloadFailedException {
return getLastModified(url, false);
}
/**
* Makes an HTTP Head request to retrieve the last modified date of the
* given URL. If the file:// protocol is specified, then the lastTimestamp
* of the file is returned.
*
* @param url the URL to retrieve the timestamp from
* @param isRetry indicates if this is a retry - to prevent endless loop and
* stack overflow
* @return an epoch timestamp
* @throws DownloadFailedException is thrown if an exception occurs making
* the HTTP request
* @deprecated this method is no longer used to check the last modified date
* of the NVD. This method will be removed in a future release.
*/
@Deprecated
private long getLastModified(URL url, boolean isRetry) throws DownloadFailedException {
final long timestamp;
//TODO use the obtain connection instead of this mostly duplicated code
if ("file".equalsIgnoreCase(url.getProtocol())) {
final File lastModifiedFile;
try {
lastModifiedFile = new File(url.toURI());
} catch (URISyntaxException ex) {
final String msg = format("Unable to locate '%s'", url.toString());
throw new DownloadFailedException(msg, ex);
}
timestamp = lastModifiedFile.lastModified();
} else {
final String httpMethod = determineHttpMethod();
HttpURLConnection conn = null;
try {
conn = connFactory.createHttpURLConnection(url);
conn.setRequestMethod(httpMethod);
conn.connect();
final int t = conn.getResponseCode();
if (t >= 200 && t < 300) {
timestamp = conn.getLastModified();
} else {
throw new DownloadFailedException(format("%s request returned a non-200 status code: %s", httpMethod, url));
}
} catch (URLConnectionFailureException ex) {
throw new DownloadFailedException(format("Error creating URL Connection for HTTP %s request: %s", httpMethod, url), ex);
} catch (IOException ex) {
checkForCommonExceptionTypes(ex);
LOGGER.error(format("IO Exception connecting to %s: %s", url, ex.getMessage()));
LOGGER.debug("Exception details", ex);
if (ex.getCause() != null) {
LOGGER.debug("IO Exception cause: " + ex.getCause().getMessage(), ex.getCause());
}
try {
//retry
if (!isRetry && settings.getBoolean(Settings.KEYS.DOWNLOADER_QUICK_QUERY_TIMESTAMP)) {
settings.setBoolean(Settings.KEYS.DOWNLOADER_QUICK_QUERY_TIMESTAMP, false);
return getLastModified(url, true);
}
} catch (InvalidSettingException ex1) {
LOGGER.debug("invalid setting?", ex1);
}
throw new DownloadFailedException(format("Error making HTTP %s request to %s", httpMethod, url), ex);
} finally {
if (conn != null) {
try {
conn.disconnect();
} finally {
conn = null;
}
}
}
}
return timestamp;
}
/**
* {@inheritDoc}
*
* Releases the underlying HTTP URL Connection.
*/
@Override
public void close() {
if (connection != null) {
try {
connection.disconnect();
} finally {
connection = null;
}
}
}
/**
* Returns whether or not the connection has been closed.
*
* @return whether or not the connection has been closed
*/
public boolean isClosed() {
return connection == null;
}
/**
* Returns the HEAD or GET HTTP method. HEAD is the default.
*
* @return the HTTP method to use
*/
private String determineHttpMethod() {
return isQuickQuery() ? HEAD : GET;
}
/**
* Determines if the HTTP method GET or HEAD should be used to check the
* timestamp on external resources.
*
* @return true if configured to use HEAD requests
*/
private boolean isQuickQuery() {
return settings.getBoolean(Settings.KEYS.DOWNLOADER_QUICK_QUERY_TIMESTAMP, true);
}
/**
* Analyzes the IOException, logs the appropriate information for debugging
* purposes, and then throws a DownloadFailedException that wraps the IO
* Exception for common IO Exceptions. This is to provide additional details
* to assist in resolution of the exception.
*
* @param ex the original exception
* @throws org.owasp.dependencycheck.utils.DownloadFailedException a wrapper
* exception that contains the original exception as the cause
*/
public void checkForCommonExceptionTypes(IOException ex) throws DownloadFailedException {
Throwable cause = ex;
while (cause != null) {
if (cause instanceof java.net.UnknownHostException) {
final String msg = format("Unable to resolve domain '%s'", cause.getMessage());
LOGGER.error(msg);
throw new DownloadFailedException(msg);
}
if (cause instanceof InvalidAlgorithmParameterException) {
final String keystore = System.getProperty("javax.net.ssl.keyStore");
final String version = System.getProperty("java.version");
final String vendor = System.getProperty("java.vendor");
LOGGER.info("Error making HTTPS request - InvalidAlgorithmParameterException");
LOGGER.info("There appears to be an issue with the installation of Java and the cacerts."
+ "See closed issue #177 here: https://github.com/jeremylong/DependencyCheck/issues/177");
LOGGER.info("Java Info:\njavax.net.ssl.keyStore='{}'\njava.version='{}'\njava.vendor='{}'",
keystore, version, vendor);
throw new DownloadFailedException("Error making HTTPS request. Please see the log for more details.");
}
cause = cause.getCause();
}
}
}