Google Chrome installation for Ubuntu

With a few simple steps, Google Chrome can be installed on Ubuntu.


wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -


sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'


sudo apt-get update


sudo apt-get install google-chrome-stable

or…


sudo apt-get install google-chrome-beta

Java User-Agent detector and caching

It’s often important for a server side application to understand the client platform. There are two common methods used for this.

  1. On the client itself, “capabilities” can be tested.
  2. Unfortunately, the server cannot easily test these, and as such must usually rely upon the HTTP Header information, notably “User-Agent”.

Example User-agent might typically look like this for a common desktop browser, developers can usually determine the platform without a lot of work.

"Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; InfoPath.3)"

Determining robots and mobile platforms, unfortunately is a lot more difficult due to the variations. Libraries as those described below simplify this work as standard Java Objects expose the attributes that are commonly expected.

With Maven, the dependencies are all resolved with the following POM addition:

<dependency>
<groupid>net.sf.uadetector</groupid>
<artifactid>uadetector-resources</artifactid>
<version>2014.10</version>
</dependency>


/* Get an UserAgentStringParser and analyze the requesting client */
final UserAgentStringParser parser = UADetectorServiceFactory.getResourceModuleParser();
final ReadableUserAgent agent = parser.parse(request.getHeader("User-Agent"));

out.append("You're a '");
out.append(agent.getName());
out.append("' on '");
out.append(agent.getOperatingSystem().getName());
out.append("'.");

As indicated on the website documentation, running this query for each request uses valuable server resources, it’s best to cache the responses to minimize the impact!

http://uadetector.sourceforge.net/usage.html#improve_performance

NOTE: the website caching example is hard to copy-paste, here’s a cleaner copy.


/*
* COPYRIGHT.
*/
package com.example.cache;

import java.util.concurrent.TimeUnit;
import net.sf.uadetector.ReadableUserAgent;
import net.sf.uadetector.UserAgentStringParser;
import net.sf.uadetector.service.UADetectorServiceFactory;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;

/**
* Caching User Agent parser
* @see http://uadetector.sourceforge.net/usage.html#improve_performance
* @author Scott Fredrickson [skotfred]
* @since 2015jan28
* @version 2015jan28
*/
public final class CachedUserAgentStringParser implements UserAgentStringParser {

private final UserAgentStringParser parser = UADetectorServiceFactory.getCachingAndUpdatingParser();
private static final int CACHE_MAX_SIZE = 100;
private static final int CACHE_MAX_HOURS = 2;
/**
* Limited to 100 elements for 2 hours!
*/
private final Cache<String , ReadableUserAgent> cache = CacheBuilder.newBuilder().maximumSize(CACHE_MAX_SIZE).expireAfterWrite(CACHE_MAX_HOURS, TimeUnit.HOURS).build();

/**
* @return {@code String}
*/
@Override
public String getDataVersion() {
return parser.getDataVersion();
}
/**
* @param userAgentString {@code String}
* @return {@link ReadableUserAgent}
*/
@Override
public ReadableUserAgent parse(final String userAgentString) {
ReadableUserAgent result = cache.getIfPresent(userAgentString);
if (result == null) {
result = parser.parse(userAgentString);
cache.put(userAgentString, result);
}
return result;
}
/**
*
*/
@Override
public void shutdown() {
parser.shutdown();
}
}

REFERENCES:

Poodle.. or rather, what’s all the fuss with SSLv3

The “Poodle” attack on websites and browsers was all over the media a few weeks ago, following in the shadow of Heartbleed.

Here’s what most users need to know… This is an vulnerability that exists in secure internet communication because…

  1. While most newer systems rely on TLS security, they still support older protocols (SSLv3 in particular for this issue)
  2. As secure communications generally attempt to find a “common” method, they will often “drop down” to older supported versions (even if they are now often considered insecure!)
  3. Most browser and server software (unless recently patched) will allow for this “drop down” in security.
  4. Most software provides a mechanism to disable this by the user or in configuration.
  5. Upgrading your software will usually remove these “problematic” vulnerabilities.

Simply put… for a consumer, it’s best to upgrade to a newer browser or find the appropriate configuration to disable SSLv3 if you are unable to upgrade. Server administrators generally should update their sofware on a regular basis for security items such as this one!

NOTE: Many CDN’s such as CloudFlare are proactive and block this vulnerability.

Technical details on the Poodle vulnerability (if you’re into that sort of thing!):

Instructions here are for Apache HTTPd 2.2.23 and newer, other servers will require a similar change:


  1. sudo vi /etc/apache2/mods-enabled/ssl.conf
  2. Change the following line from:
    SSLProtocol All -SSLv2
    to:
    SSLProtocol All -SSLv2 -SSLv3
  3. sudo service apache2 reload
  4. sudo service apache2 restart

Can be tested at the following websites:

REFERENCES:

MKS IntegrityClient integration with Eclipse IDE

While the intgration plugins for most SCM products are done rather simply within Eclipse, MKS(now PTC) IntegrityClient requires a few manual steps.

Caution, the plugin has always been a bit “buggy” but nothing too annoying for daily use. I’ve personally used it since IBM WSAD 5.1(Eclipse 3.x based) up to and including the most current Eclipse Luna (4.4) release.

  1. Go to your MKS installation path, then find the “integrations” folder as in the example below:
    C:\MKS\IntegrityClient\integrations\IBM\eclipse_3.2\eclipse
  2. That folder SHOULD have two folders (features/plugins) as well as three files (.eclipseextension, artifacts.xml, content.xml)
  3. Copy the entire contents and paste/overlay into your ‘eclipse’ folder (where you should already have folders for ‘features/plugins)
  4. Restart Eclipse
  5. Configure as required.

clientaccesspolicy.xml

Similar to ‘crossdomain.xml’, Silverlight has some security features, this too is often noticeable by large number of HTTP 404 errors for a file named ‘clientaccesspolicy.xml’ in my webserver logs.

The most simple solution to the 404’s that restricts Silverlight is to add an empty file at the root of your websites.

REFERENCES:

Preventing Pinterest “pinning” of your content

While many people are happy when images from their websites get “pinned” on Pinterest, there are many times that you might not be so pleased. You may have a need to prevent images from being shared for copyright or similar reasons, or simply not want the extra website traffic.

Thankfully, you can stop this with the addition of a simple HTML META tag. Also, if you already use CloudFlare, they can add it for you at runtime!


<meta name="pinterest" content="nopin" />

REFERENCES:

Skype toolbar meta tag… preventing Skype from messing up your UI

I’ve previously documented the method used to prevent IOS devices from formatting numbers.

Users on other platforms, notably Windows, have Skype installed and it too can cause some headaches with your UI as it inserts elements to decorate phone numbers.

For users that have the Skype Toolbar enabled, the following META tag will prevent it from doing a lot of damage!

<meta name="SKYPE_TOOLBAR" content="SKYPE_TOOLBAR_PARSER_COMPATIBLE" />

REFERENCES:

HTML cleartype meta tag?

This tag allows for activation of ClearType in Mobile IE for smoothing fonts.


<!--[if IEMobile]><meta http-equiv="cleartype" content="on" /><![endif]-->

NOTE: Future use of this approach is questionable, as MSIE10 dropped support of conditional comments, and HTML5 validators (in general) do not “like” the http-equiv values as they are not standardized

REFERENCES:

Preventing IOS/Safari from formatting numbers

There are many cases where your application may display numbers that “resemble” phone numbers, but are not, unfortunately Safari’s default behavior is for it to be “helpful” and format them into clickable/callable links for the user of Apple IOS devices.

Adding the following META tag can prevent that default behavior:

<meta name="format-detection" content="telephone=no" />
.

NOTE: I’ve seen some mention of using this method for ‘address=no’ and ’email=no’, but have not looked into or verified those implementation yet!

REFERENCES:

opensearchdescription.xml

OpenSearch is a relatively obscure topic that I’ve only crossed a few times, here is the premise.

A simple tag can be added to your content, in this case HTML, but a feed can also contain this element.

<link rel="search" href="http://www.giantgeek.com/opensearchdescription.xml" type="application/opensearchdescription+xml" title="giantgeek.com" />

That link refers to a file that resembles the one below, in it you can specify the URL to the search facilities on a website, or as in the case below, use the parameters for a Google search of your website.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE OpenSearchDescription>
<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/" xmlns:moz="http://www.mozilla.org/2006/browser/search/">
<ShortName>GiantGeek.com</ShortName>
<Description>Use Google to search our web site.</Description>
<InputEncoding>UTF-8</InputEncoding>
<Tags>giantgeek skotfred</Tags>
<Contact>[email protected]</Contact>
<Image width="16" height="16" type="image/x-icon">http://www.giantgeek.com/favicon.ico</Image>
<!-- NOTE: this uses Google, you can give your own search url instead -->
<Url type="text/html" method="GET" template="http://www.google.com/search?q=site:giantgeek.com {searchTerms}"/>
<Url type="application/opensearchdescription+xml" rel="self" template="http://www.giantgeek.com/opensearchdescription.xml"/>
</OpenSearchDescription>

Many modern browsers that provide a ‘search box’ in the browser interface, can then add the capability to perform a search of your website even when the user is not there already.

REFERENCES and Additional Reading: