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Tuesday, January 31, 2012

Kazam Screencaster 1.0 Released

http://www.webupd8.org/2012/01/kazam-screencaster-10-released.html
 ~ Web Upd8: Ubuntu / Linux blog

Kazam Screencaster 1.0, a cool screencasting application for Linux, has been released today.

The Kazam Screencaster development has stopped a while back, but luckily a new developer has taken over the project and Kazam is updated frequently again. With the new 1.0 version, Kazam is finally GTK3 ready, but that's not all. Here are the changes since the previous Kazam version we wrote about (a long time ago, I know):

  • It's finally possible to record arbitrary screen regions
  • Support for two audio channels, with volume settings
  • Output can be saved in WebM or Matroska
  • Uses gstreamer instead of ffmpeg
  • Countdown timer is now customizable
  • Countdown window has now variable width
  • Adjustable framerate
  • Ability to turn off recording of mouse cursor
  • Audio device selection is now done directly from PulseAudio. To record application sounds instead of microphone input you will have to select one of the monitor devices.

Even though it uses an Ubuntu AppIndicator, Kazam works in other desktop environments too, like GNOME Shell for instance (GNOME Shell has a built-in recording tool which works great, but it doesn't let you select an arbitrary screen region), where it falls back to a regular tray icon.

Sunday, January 29, 2012

10 Apache Security and Hardening Tips

http://www.kyplex.com/docs/apache-security.html
 | Kyplex cloud security

The Apache web server is a crucial part of the website infrastructure. It has a number of built in features that can improve your website resistance to attacks. The following document covers a number of steps that will help you to achieve this goal. This document is largely based on the knowledge gathered by our security team and by statistics information revealed by our security scanner.

Tip No. 1: Disable Apache Signature and/or Apache Banner

Apache Signature or Apache Banner is basically the same thing. It is an application name together with version name that is printed when performing a web request. Nobody actually needs this information at all, but it is enabled by default. You need to alter the Apache configuration file to disable it.
In Ubuntu, you need to change the following file: /etc/apache2/apache2.conf
Double check that ServerSignature and ServerTokens configuration settings are not enabled in some other parts of the configuration file.

Tip No. 2: The Trace HTTP Request

HTTP TRACE request is used to echo back all received information. It can be tricked to print HTTP cookies and as a result steal HTTP session. Basically this request can be used as part of the Cross Site Scripting attack, or XSS. It is recommended to disable it as a security precaution.
Add the following to the web-server's configuration file. For example alter the following file in Ubuntu: /etc/apache2/apache2.conf .

Tip 3: Remove PHP scripts that print debug info using phpinfo()

The built-in PHP function phpinfo() prints a lot of interesting internal information about the PHP environment. It can include list of which PHP modules are enabled, and the location of various files on the web-server and other sensitive information. Our web security scanner finds a lot of such files. It is recommended to remove these test files from a production website.
Here is a tip hpw to find such files. Look for the files with the following name: test.php,info.phpi.php and phpinfo.php in your website directory and remove them.

Tip 4: Disable directory indexing

Directory indexing is a features found in every web-server by default. When directory indexing is enabled, the web-site prints a list of files found in the website directories when the default page does not exists (for example index.php). Directories reported can be viewed by any visitor. It is vulnerable in the sense that these directories can contain configuration, private and backup files which can be used by the attackers to take your server under control.
You can fix this problem by disabling the Apache autoindex module. In some Apache installations it is called mod_autoindex.so. In Ubuntu, you just need to remove the following files:
So you can do it running the following commands:

Tip 5: Disable WebDAV

WebDAV is a file access protocol created over HTTP protocol. It allows you to upload and download files, and change file contents from the website. This service is required only in very rare cases. From our experience, this feature was only required to run SVN server (link). Make sure that WebDAV is disabled in production websites. When WebDAV is enabled, the following commands are supported by Apache: OPTIONS, PROPFIND, etc. These commands are sensitive from computer security point of view.
You can fix this problem by disabling Apache dav, dav_fs and dav_lock modules. In Ubuntu you just need to remove the following files:
So you can do it running the following commands:

Tip 6: Create a chroot'ed Apache environment

Chroot is a kind of virtual environment supported operating systems such as Linux and FreeBSD. When an application is executed in chrooted environment it has no access to the parent disk and to other recources.
This is a good solution if you want to protect your website from malicious users. The action steps required to create chroot Apache was already covered in a number of websites. For example: http://www.linux.com/archive/feed/36331
The main hidden issue with chrooted environment is that this environment protects the websites from accessing the operating system's files. It does not protect one site from another. In other words, if a malicious script located in one site it can access files located on other site because they are located on the same chrooted environment.
A solution to this problem is the following. Create a number of apache instances, each one hosting one website running each one if different chrooted directory. These apache instances will not be able to share IP addresses. You will have to configure different IP for each Apache instance you run.

Tip 7: Enable PHP basedir

PHP has built in a kind of chroot environment. It is called "basedir". You can configure PHP scripts to access files only in specific directory similar to chroot. Basically you can configure each site to access only files located in that site directory which is a very good idea from the security point of view.
You can add the following lines to the website configuration file or to .htaccess file to enable PHP basedir:
This will specify that your PHP scripts can access only specified directories.

Tip 8: Web Stats

Some webmasters install open source tools on their website that analyze web requests and create statistical reports. Access to these webstat scrips is almost never secured with a password. So any visitor can basically view such reports. For example some webmasters install in in the /stats directory accessible by http://www.my-site.com/stats .
Statistical reports contain a lot of sensitive information. For example it can contain hidden file names and directory names, full web requests, search engine keywords, etc... All this information can be used by the malicious users and/or your competitors.
Instead of running a statistics script on your website we recommend that you use Google Analytics. It is a free-of-charge and quality service.

Tip 9: Use Google

Most of the webmasters use common web scripts and CMS or blog software. We recommend you to frequently search for security updates using Google and register for security news at your blog/CMS website.

Tip 10: Additional Steps

If your webserver runs together with MySQL server it brings additional potential security problem. MySQL can read any files located on you server including the one located in different chrooted environments. It happens because of the FILE permission. By default only MySQL root has it. For more info about MySQL security take a look at this article ( link to GreenSQL) .
Install a Database Firewall
Download GreenSQL Express which is a free version of the GreenSQL database firewall.
Install a Web Firewall
Mod_security is a good open source product.
Additional links

Free Tools to Edit Product Shots for Your Online Store

http://www.ecommerce-guide.com//article.php/3939786
 — eCommerce-Guide.com

By Vangie Beal
January 25, 2012

If you own an online store, it's a good practice to ensure you offer shoppers clear and professional-lookingproduct images. The images you use in your store will rouse consumer interest in your products. A plain or poor-quality digital photo of the item you sell is just not enough to inspire a purchase.  
Online store owners and eBay sellers working with a limited budget can skip the cost of purchasing commercial image editing software and use free Web-based or open source tools to perk up product shots.

5 Free Image Tools for Online Store Owners

There are a number of basic functions that you will want to use to fix up product shots, so even if the editor is free, save time by making sure the basic options are available. Look for crop, rotate and brushes. And be sure it includes a text editor in case you need to add a copyright tag or caption directly on to the image. Remember that using too many special image effects will make your product shot look fake, so stick with the tools that enhance the natural look of the product in your online store.
Here are five free image editors to get you started.

1. GIMP:  The GNU Image Manipulation Program

GIMP is one of the most well-known an open source image editors. It comes complete with layering, brushes, lighting and more features that let you add a cutting-edge look to your images.  Online store owners will want to work with some of the tools for rotation, cropping and text.
If you need help using GIMP, a simple Google search will yield a number of articles on how to effectively use some of the tools in the program. More advanced users can download additional scripts and brushes.
  • Main features:  .gif animation capabilities, brushes, layering with blend modes, filtering and color effects, transformation tools, a text editor and photo creation capabilities.
  • Cost: GIMP is open source software (so it's free) and available for Windows, Mac, Linux and UNIX systems.

2. Pixlr:  Web-Based Image Editing with Drop-Down Menus

Pixlr is a Web-based image editing program that can help online store owners make images and product shots look snazzy and appealing to your site viewers and customers.  The image editor features movable (and scalable) windows for editing, drop-down menus to use effects, filters, brushes and other image editing tools. Pixlr offers an easy-to-use text editor, so you can add slogans and catchy phrases to your images and Web advertisements.
Since Pixlr is a Web-based image editing tool, you don't have to download or install anything. You simply load it into your Web browser.
  • Main features: easy drop-down menus, filters and effects, brushes, transformations, text editor and no downloading because it's Web-based. 
  • Cost: Pixlr is free -- no credit cards, accounts, or trials. It's available on all operating systems with an up-to-date Web browser. It also works with Android and Apple iOS devices.

3. Splashup: Free Web Editing with Social Sharing

Splashup is another Web-based image editor that can be used in conjunction with popular photo sharing services like Facebook and Flickr. This social integration allows Web shop owners to access photos directly and not have to download them to a hard drive, edit, then upload them.
Splashup offers a number of features including layers with blending modes and numerous effects and filters to spice-up your product shots and other business images.
  • Main Features: integrated photo sharing, layering with blend modes, filters and effects, text editor, edit photos directly off of a webcam, and it's Web-based.
  • Cost: Splashup is completely free, and requires no credit cards or accounts; you just open the Web page and edit your photos. It works on any operating system with an up-to-date Web browser.

4. Picasa: Organize, Store and Edit Images

Picasa is a free program offered by Google that lets you host, organize and edit all images on your computer. It's pretty simple: after you install Picasa, it searches for all images on your hard drives. Once it has indexed them, it stores them in a library for easy access.  Features include basic image fixes, such as color and contrast, and you can crop, rotate and add text. There are several effects and filters you can use to turn plain images in to showcase quality.
Picasa is a basic program, but it's user-friendly and meets the needs of most online store owners who need to liven up a few product images.
  • Main Features: create a photo library to index your images, includes all basic editing tools, filters and effects and a text editor.
  • Cost:  Picasa is completely free to download and use. It works on Windows, Mac and Linux systems.

5. Fotoflexer: A Web-Based Tool with a Simple Interface

Fotoflexer is another Web-based image editor that offers a decent number of features and a simple interface that makes editing images a painless task.  Fotoflexer integrates with images and photos on a number of popular social sites including Facebook, MySpace, Flickr and Photobucket. The Web tool offers most of the basic image editing tools such as crop, resize, rotate and text editing. Online store owners can also add image effects and filters to give product shots a unique look.
  • Main Features: integrated photo sharing, all basic photo editing tools, text editor, effects and filters, and it's Web-based.
  • Cost:  Fotoflexer is completely free, and works with any operating system with an up-to-date browser, since it is Web-based.

More Online Store Product Page Tips

Looking to get a better handle on improving your online store? Try these tips and guides for small business ecommerce sites:
Based in Nova Scotia, Canada, Vangie Beal has spent the last decade contributing featured articles and reviews to more than 20 technology-focused publications, including Webopedia and Ecommerce-Guide. You can tweet with her online @AuroraGG

Wednesday, January 25, 2012

Ramhost上建立OpenVPN

http://jolestar.com/move-blog-to-ramhost
 | 午夜咖啡

Ramhost上只能搭建openvpn
(搭建教程在此:https://forum.ramhost.us/bbs/viewtopic.php?id=4)。

Android默认不支持openvpn,于是又在手机上折腾openvpn。需要有root权限,
  1. 先安装 BusyBox(有的改造版的ROM里会带着) ,
  2. 再安装OpenVPN Installer,OpenVPN Settings。
  3. 将openvpn client 的配置文件,证书以及key拷贝到手机的/sdcard/openvpn/文件夹里,运行OpenVPN Settings进行设置就可以了。

需要注意的是要启用Open VPN Settings的 Fix DNS功能,否则被功夫网dns污染的网站(如 twitter,youtube)也是无法访问的。

Thursday, January 5, 2012

California State Senator Proposes Funding Open-Source Textbooks

http://politics.slashdot.org/story/12/01/05/1615210/california-state-senator-proposes-funding-open-source-textbooks?utm_source=feedburnerGoogle+Feedfetcher&utm_medium=feed&utm_campaign=Feed%3A+Slashdot%2Fslashdot+%28Slashdot%29&utm_content=Google+Feedfetcher
 - Slashdot

"Although former Governor Schwarzenegger's free digital textbook initiative for K-12 education was a failure, state senator Darrell Steinberg has a new idea for the state-subsidized publication of college textbooks (details in the PDF links at the bottom). Newspaper editorialsseem positive. It will be interesting to see if this works any better at the college level than it did for K-12, where textbook selection has traditionally been very bureaucratic. This is also different from Schwarzenegger's FDTI because Steinberg proposes spending state money to help create the books. The K-12 version suffered from legal uncertainty about the Williams case, which requires equal access to books for all students — many of whom might not have computers at home. At the symposium where the results of the FDTI's first round were announced, it became apparent that the only businesses interested in participating actively were not the publishers but computer manufacturers like Dell and Apple, who wanted to sell lots of hardware to schools."

Sunday, January 1, 2012

Wordnik’s Online Dictionary - No Arbiters, Please

http://www.nytimes.com/2012/01/01/business/wordniks-online-dictionary-no-arbiters-please.html?partner=rss&emc=rss
 - NYTimes.com
TRADITIONAL print dictionaries have long enlisted lexicographers to scrutinize new words as they pop up, weighing their merits and eventually accepting some of them.
Erin McKean is a founder of Wordnik, the online dictionary.
Not Wordnik, the vast online dictionary.
No modern-day Samuel Johnson or Noah Webster ponders each prospective entry there. Instead, automatic programs search the Internet, combing the texts of news feeds, archived broadcasts, the blogosphere, Twitter posts and dozens of other sources for the raw material of Wordnik citations, says Erin McKean, a founder of the company.
Then, when you search for a word, Wordnik shows the information it has found, with no editorial tinkering. Instead, readers get the full linguistic Monty.
"We don't pre-select and pre-prune," she said. "We show you what's out there now. Then we let people decide whether to use a word or not."
At one time, she was the head of the pruners, as principal editor of the New Oxford American Dictionary. She is also an author and columnist. (She wrote "On Language" columns for The New York Times as a substitute for William Safire.)
But Ms. McKean has chosen a different path at Wordnik. "Language changes every day, and the lexicographer should get out of the way," she said. "You can type in anything, and we'll show you what data we have."
When readers ask about a word, Wordnik provides definitions on the left-hand side of the screen. But it is the example sentences, featured on the right-hand side, that are crucial to a reader's understanding of a new term, she said.
"Dictionary definitions tend to be out of date or incomplete," she said. "Our goal is to find examples on the Web that use the word so clearly that you can understand its meaning from reading the sentence."
To do this, the site processes a vast reservoir of language, keeping tabs on more than six million words automatically, said Tony Tam, Wordnik's vice president for engineering. "But the numbers change every second," he said. "It's not a static list."
Where does all this text come from? "You'd be amazed how fast people write articles on the Web," he said.
Wordnik does indeed fill a gap in the world of dictionaries, said William Kretzschmar, a professor at the University of Georgia and the former president of the American Dialect Society. He provides American pronunciations for the new online Oxford English Dictionary.
"It takes time for words to get into the more formal, published dictionaries," he said. "Wordnik is sensitive to what people are interested in now."
Wordnik, which has raised $12.8 million in venture financing, plans to use its vast database of words and word associations at the site and in many business partnerships to be announced this year, said Joe Hyrkin, the president and C.E.O.
The products will be similar to recommendation engines, but more powerful, he said. If you like a particular book, for example, Wordnik can recommend a similar one based on its understanding of words used to describe the book, he said.
"We're not just using tags and descriptors," he said. "Our system understands and identifies matches at a concept level."
The company is already providing many other word-based services, including one used on the Web site of The Times to define words in articles. Wordnik is also providing a financial glossary for SmartMoney.com.
Geoffrey Nunberg, a linguist at the School of Information at the University of California, Berkeley, who talks about language on "Fresh Air," the NPR program, appreciates Wordnik's breadth. "There's a lot of useful information here," he said. (He has also written commentaries on language for The Times.)
But he thinks that hands-on lexicographers could fine-tune the entries.
"The idea that you can pull lexicographers out of the loop and have an algorithm to mediate between me and the English language is goofy," he said. "Without hand citations done by trained people, you get a mess."
To illustrate his point, he noted flaws in a number of Wordnik's definitions. The first definition of "davenport," for instance, in three of the fives sources used by Wordnik is a kind of small writing desk. "It hasn't meant that since Grandma was a girl," he said.
People use a dictionary to find out what is correct, and what is incorrect, he said. "If I were a journalist looking to see if a word was being used correctly," he said, "I wouldn't put my eggs in the Wordnik basket."
Mr. Tam of Wordnik said the site was constantly improving.
"We discover these words with algorithms, but they are never perfect," he said. "We constantly have to make them better."
WORDNIK and other new linguistic databases have come about largely because of the vast body of text on the Internet and improved algorithms for searching it, said Mark Liberman, a professor of linguistics at the University of Pennsylvania.
"We now have an archived shadow universe that contains almost everything we've written — trillions of pages of text of published books, and now, broadcast archives as well," he said.
Readers could always tap this reservoir by looking up examples of new words in Google Books or Google News. "But what Wordnik is giving you is not as raw as a Google search of examples," he said, "because Wordnik sorts and clusters the examples into different senses of the word."
Another innovative database is at Brigham Young University, where Mark Davies, a professor of linguistics, has amassed a collection, the Corpus of Contemporary American English, 1990-2011, containing millions of words of running text from articles, transcripts of conversations, and other sources. The collection, which indexes 425 million words of text — 1,000 may be from a newspaper article, for example — has been built over the last three years. It shows how often a word is used, and the types of discourse in which it is found, be it conversational speech or academic prose.
The collection also lets users see words found near a new word. "If you want to see how a word is used and what it means, the best way is to look at words nearby," Dr. Davies said. The words are called collocates. To look up collocates of "fantasy," for example, seehttp://bit.ly/rImCuH.
Dictionary builders have come a long way since the days of Johnson and Webster, said Dr. Kretzschmar at the University of Georgia. "But we have computers," he said. "We can manage this vast network of words online and appreciate it in ways that Johnson and Webster never could."
This article has been revised to reflect the following correction:
Correction: December 31, 2011
An earlier version of this article misspelled the given name of Wordnik's chief executive. He is Joe Hyrkin, not Joel.

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