The Sun BabelFish Blog

November 2nd: Join the Social Web Camp in Santa Clara

Henry Story — 2009-10-15T15:35:54-07:00

The W3C Social Web Incubator Group is organizing a free Bar Camp in the Santa Clara Sun Campus on November 2nd to foster a wide ranging discussion on the issues required to build the global Social Web.

Imagine a world where everybody could participate easily in a distributed yet secure social web. In such a world every individual will control their own information, and every business could enter into a conversation with customers, researchers, government agencies and partners as easily as they can now start a conversation with someone on Facebook. What is needed to go in the direction of The Internet of Subjects Manifesto? What existing technologies can we build on? What is missing? What could the W3C contribute? What could others do? To participate in the discussion and meet other people with similar interests, and push the discussion further visit the Santa Clara Social Web Camp wiki and

If you are looking for a reason to be in the Bay Area that week, then here are some other events you can combine with coming to the Bar Camp:

The W3C is meeting in Santa Clara for its Technical Plenary that week in Santa Clara.
The following day, the Internet Identity Workshop is taking place in Mountain View until the end of the week. Go there to push the discussion further by meeting up with the OpenId, OAuth, Liberty crowd, which are all technologies that can participate in the development of the Social Web.
You may also want to check out ApacheCon which is also taking place that week.

If you can't come to the west coast at all due to budget cuts, then not all is lost. :-) If you are on the East coast go and participate in the ISWC Building Semantic Web Applications for Government tutorial, and watch my video on The Social Web which I gave at the Free and Open Source Conference this summer. Think: if the government wants to play with Social Networks, it certainly cannot put all its citizens information on Facebook.

One month of Social Web talks in Paris

Henry Story — 2009-10-12T10:16:41-07:00

As I was in Berlin preparing to come to Paris, I wondered if I would be anywhere near as active in France as I had been in Germany. I had lived for 5 years in Fontainebleau, an hour from Paris, close but just too far to be in the swing of things. And from that position, I got very little feel for what was happening in the capital. This is what had made me long to live in Paris. So this was the occasion to test it out: I was going to spend one month in the capital. On my agenda there was just a Social Web Bar Camp and a few good contacts.

The Social Web Bar Camp at La Cantine which I blogged about in detail, was like a powder keg for my stay here. It just launched the whole next month of talks, which I detail below. It led me to make a very wide range of contacts, which led to my giving talks at 2 major conferences, 2 universities, one other Bar Camp, present to a couple of companies, get one implementation of foaf+ssl in Drupal, and meet a lot of great people.

Through other contacts, I also had an interview with a journalist from Le Monde, and met the very interesting European citizen journalism agency Cafe Babel (for more on them see this article).

Here follows a short summary of each event I presented the Social Web at during my short stay in Paris.

Friday, 18 September 2009

Arrived in plane from Berlin, and met the journalists at the Paris offices of Cafe Babel, after reading an article on them in the July/August issue of Internationale Politik, "Europa aus Erster Hand".

Saturday, 19 September 2009

Went to the Social Web Bar Camp at La Cantine which I blogged about in detail. Here I met a many people, who connected me up with the right people in the Paris conference scene, where I was then able to present. A couple of these did not work out due to calendar clashes, such as an attempted meeting with engineers and users of Elgg a distributed Open Source Social Networking Platform popular at Universities here in France and the UK.

Monday, 21 September 2009

Visited the offices of Le Monde, and had lunch with a journalist there. I explain my vision of the Social Web and the functioning of foaf+ssl. He won't be writing about it directly he told me, but will develop these ideas over time in a number of articles. ( I'll post updates here, though it is sadly very difficult to link to articles in Le Monde, as they change the URLs for their articles, make them paying only after a period of time, and then don't even make an abstract available for non paying members).

Friday, 25 September 2009

I visited the new offices of af83.com a startup with a history: they participated in the building of the web site of Ségolène Royal the contender with Nicholas Sarkozi, during the last French Presidential Elections.
There I met up with Damien Tournoud, and expert Drupal Developer, explained the basics of foaf+ssl, pointed him to the Open Source project foaf.me, and let him work on it. With a bit of help from Benjamin Nowack the creator of the ARC2 Semantic Web library for PHP, Damien had a working implementation the next day. We waited a bit, before announcing it the following Wednesday on the foaf-protocols mailing list.

Tuesday 29 September, 2009

La Cantine organised another Bar Camp, on a wide range of topics, which I blogged about in detail. There I met people from Google, Firefox, and reconnected up with others. We also had a more open round table discussion on the Social Web.

Thursday 1st and Friday 2nd October, 2009

I visited the Open World Forum, which started among others with a track on the Semantic Desktop "Envisioning the Open Desktop of the future", headed by Prof Stefan Decker, with examples of implementations in the latest KDE (K Desktop Environment).
I met a lot of people here, including Eric Mahé, previously Technology Advisor at Sun Microsystems France. In fact I met so many people that I missed most of the talks. One really interesting presentation by someone from a major open source code search engine, explained that close to 60% of Open Source software came from Eastern and Western Europe combined. (anyone with a link to the talk?)

Saturday, 3rd October 2009

I presented The Social Web in French at the Open Source Developer Conference France which took place in La Villette.
I was really happily surprised to find that I was part of a 3 hour track dedicated to the Semantic Web. This started with a talk by Oliver Berger "Bugtracking sur le web sémantique. Oliver has been working on the Baetle ontology as part of the 2 year government financed HELIOS project. This is something I talked about a couple of years ago and wrote about here in my presentation Connecting Software and People. It is really nice to see this evolving. I really look forward to seeing the first implementations :-)
Oliver's was followed by a talk by Jean-Marc Vanel, introducing Software and Ontology Development, who introduced many of the key Semantic Web concepts.

Tuesday 6th October, morning

Milan Stankovitch whom I had met at the European Semantic Web Conference, and again at the Social Web Bar Camp, invited me to talk to the developers of hypios.com, a very interesting web platform to help problem seekers find problem solvers. The introductory video is really worth watching. I gave them the talk I keep presenting, but with a special focus on how this could help them in the longer term make it easier for people to join and use their system.

Tuesday 6th September, afternoon

I talked and participated in a couple of round table talks at the 2nd Project Accelerator on Identity at the University of Paris 1, organised by the FING. Perhaps the most interesting talk there was the one by François Hodierne , who works for the Open Source Web Applications & Platforms company h6e.net, and who presented the excellent project La Distribution whose aim it is to make installing the most popular web applications as easy as installing an app on the iPhone. This is the type of software needed to make The Internet of Subjects Manifesto a reality. In a few clicks everyone should be able to get a domain name, install their favorite web software on it - Wordpress, mail, wikis, social network, photo publishing tool - and get on with their life, whilst owning their data, so that if they at a later time find the need to move, they can, and so that nobody can kick them off their network. This will require rewriting a little each of the applications so as to enable them to work with the distributed secure Social Web, made possible by foaf+ssl: an application without a social network no longer being very valuable.

Thurday 9th October, 2009

Pierre Antoine Champin from the CNRS, the National French Research organisation, had invited me to Lyon to present The Social Web. So I took the TGV from Paris at 10:54 and was there 2 hours later, which by car would have been a distance of 464km (288.3 miles) according to Google Maps. The talk was very well attended with close to 50 students showing up, and the session lasted two full hours: 1 hour of talks and by many good questions.
After a chat and a few beers, I took the train back to Paris where the train arrived just after 10pm.

Saturday October 10, 2009

I gave a talk on the Social Web at Paris-Web, on the last day of a 3 day conference. This again went very well.
After lunch I attended two very good talks that complemented mine perfectly:

David Larlet had a great presentation on Data Portability, which sparked a very lively and interesting discussion. Issues of Data ownership, security, confidentiality, centralization versus decentralization came up. One of his slides made the point very well: by showing the number of Web 2.0 sites that no longer exist, some of them having disappeared by acquisition, others simply technical meltdown, leaving the data of all their users lost forever. (Also see David's Blog summary of Paris-Web. )
Right after coffee we had a great presentation on the Semantic Web by Fabien Gandon, who managed to give in the limited amount of time available to him an overview of the Semantic Web stack from bottom to top, including OWL 1 and 2, Microformats, RDFa, and Linked data, and various very cool applications of it, that even I learned a lot. His slides are available here. He certainly inspired a lot of people.

Tuesday, 13 October 2009

Finally I presented at the hacker space La suite Logique, which takes place in a very well organized very low cost lodging space in Paris. They had presentations on a number of projects happening there:

One project is to build a grid by taking pieces from the remains of computers that people have brought them. They have a room stashed full of those.
Another projects is to add wifi to the lighting to remotely control the projectors for theatrical events taking place there.
There was some discussion on how to add sensors to dancers, as one Daito Manabe a Japanese artist has done, in order to create a high tech butoh dance (see the great online videos).
Three engineers presented the robots they are constructing for a well known robot fighting competition

Certainly a very interesting space to hang out in, meet other hackers, and get fun things done in.

All of these talks were of course framed by some great evenings out, meeting people, and much more, which I just don't have time to write down right here. Those were the highlights of my month's stay in Paris. I must admit that I really had no idea it to be so active!

Sketch of a RESTful photo Printing service with foaf+ssl

Henry Story — 2009-10-07T12:15:50-07:00

Let us imagine a future where you own your data. It's all on a server you control, under a domain name you own, hosted at home, in your garage, or on some cloud somewhere. Just as your OS gets updates, so all your server software will be updated, and patched automatically. The user interface for installing applications may be as easy as installing an app on the iPhone ( as La Distribution is doing).

A few years back, with one click, you installed a myPhoto service, a distributed version of fotopedia. You have been uploading all your work, social, and personal photos there. These services have become really popular and all your friends are working the same way too. When your friends visit you, they are automatically and seamlessly recognized using foaf+ssl in one click. They can browse the photos you made with them, share interesting tidbits, and more... When you organize a party, you can put up a wiki where friends of your friends can have write access, leave notes as to what they are going to bring, and whether or not they are coming. Similarly your colleagues have access to your calendar schedule, your work documents and your business related photos. Your extended family, defined through a linked data of family relationship (every member of your family just needs to describe their relation to their close family network) can see photos of your family, see the videos of your new born baby, and organize Christmas reunions, as well as tag photos.

One day you wish to print a few photos. So you go to web site we will provisionally call print.com. Print.com is neither a friend of yours, nor a colleague, nor family. It is just a company, and so it gets minimal access to the content on your web server. It can't see your photos, and all it may know of you is a nickname you like to use, and perhaps an icon you like. So how are you going to allow print.com access to the photos you wish to print? This is what I would like to try to sketch a solution for here. It should be very simple, RESTful, and work in a distributed and decentralized environment, where everyone owns and controls their data, and is security conscious.

Before looking at the details of the interactions detailed in the UML Sequence diagram below, let me describe the user experience at a general level.

You go to print.com site after clicking on a link a friend of your suggested on a blog. On the home web page is a button you can click to add your photos.
You click it, and your browser asks you which WebID you wish to use to Identify yourself. You choose your personal ID, as you wish to print some personal photos of yours. Having done that, your are authenticated, and print.com welcomes you using your nicknames and displays your icon on the resulting page.
When you click a button that says "Give Print.com access to the pictures you wish us to print", a new frame is opened on your web site
This frame displays a page from your server, where you are already logged in. The page recognized you and asks if you want to give print.com access to some of your content. It gives you information about print.com's current stock value on NASDAQ, and recent news stories about the company. There is a link to more information, which you don't bother exploring right now.
You agree to give Print.com access, but only for 1 hour.
When your web site asks you which content you want to give it access to, you select the pictures you would like it to have. Your server knows how to do content negotiation, so even though copying each one of the pictures over is feasible, you'd rather give print.com access to the photos directly, and let the two servers negotiate the best representation to use.
Having done that you drag and drop an icon representing the set of photos you chose from this frame to a printing icon on the print.com frame.
Print.com thanks you, shows you icons of the pictures you wish to print, and tells you that the photos will be on their way to your the address of your choosing within 2 hours.

In more detail then we have the following interactions:

Your browser GETs print.com's home page, which returns a page with a "publish my photos" button.
You click the button, which starts the foaf+ssl handshake. The initial ssl connection requests a client certificate, which leads your browser to ask for your WebID in a nice popup as the iPhone can currently do. Print.com then dereferences your WebId in (2a) to verify that the public key in the certificate is indeed correct. Your WebId (Joe's foaf file) contains information about you, your public keys, and a relation to your contact addition service. Perhaps something like the following:
```
:me xxx:contactRegistration </addContact> .
```
Print.com uses this information when it creates the resulting html page to point you to your server.
When you click the "Give Print.com access to the pictures you wish us to print" you are sending a POST form to the <addContact> resource on your server, with the WebId of Print.com <https://nasdaq.com/co/PRNT#co> in the body of the POST. The results of this POST are displayed in a new frame.
Your web server dereferences Print.com, where it gets some information about it from the NASDAQ URL. Your server puts this information together (4a) in the html it returns to you, asking what kind of access you want to give this company, and for how long you wish to give it.
You give print.com access for 1 hour by filling in the forms.
You give access rights to Print.com to your individual pictures using the excellent user interface available to you on your server.
When you drag and drop the resulting icon depicting the collection of the photos accessible to Print.com, onto its "Print" icon in the other frame - which is possible with html5 - your browser sends off a request to the printing server with that URL.
Print.com dereferences that URL which is a collection of photos it now has access to, and which it downloads one by one. Print.com had access to the photos on your server after having been authenticated with its WebId using foaf+ssl. (note: your server did not need to GET print.com's foaf file, as it still had a fresh version in its cache). Print.com builds small icons of your photos, which it puts up on its server, and then links to in the resulting html before showing you the result. You can click on those previews to get an idea what you will get printed.

So all the above requires very little in addition to foaf+ssl. Just one relation, to point to a contact-addition POST endpoint. The rest is just good user interface design.

What do you think? Have I forgotten something obvious here? Is there something that won't work? Comment on this here, or on the foaf-protocols mailing list.

Notes

print.com sequence diagram by Henry Story is licensed under a Creative Commons Attribution 3.0 United States License.
Based on a work at blogs.sun.com.

foaf+ssl in Mozilla's Fennec works!

Henry Story — 2009-09-30T02:38:49-07:00

At yesterday's Bar Camp in La Cantine I discovered that Mozilla's Fennec browser for mobile phones can be run on OSX (download 1.0 alpha 1 here). So I tried it out immediately to see how much of the foaf+ssl login would work with it. The answer is all of it, with just a few easy to fix user experience issues. I really am looking forward to trying the Nokia N810 Internet Tablet for real.

Anyway here are quick snapshots of the user experience.

Getting a certificate

First of all the best news is that the <keygen> tag, now documented in html5 works in Fennec. This means that one can get a client certificate in one click without going through the complex dance I described in "howto get a foaf+ssl certificate to your iPhone".

This is how easy it can be. Go to foaf.me.

After filling out the form, you can create yourself an account on foaf.me:

To make your WebId useful all you need to do is click on the "Claim account with SSL certificate" button -- which could certainly be phrased better -- on the account creation successful page:

Once clicked, your browser will start calculating a new public private key pair, send the public key to the server which will turn it into a certificate, and send that back to your browser, which will then add it to they keychain! All you will see of this whole transaction is:

The Fennec message here is a bit misleading: you should not in fact need to keep a backup copy of your certificate. Foaf+ssl certificates are very cheap to produce. And without a link to the keychain from the popup, most users won't know what is being talked about, or how to keep a backup. Also on a cell phone they may well wonder where to put the backup anyway. So in this case it is wrong, and not that helpful. Much better would be to have a popup say: "Your certificate has been installed. Would you like to see it?" Or something like that. Most people won't care.

Using the certificate

You can then test the foaf+ssl certificate on any number of sites. The foaf.me site has a login button for example that when clicked will get the browser to ask the user to choose a certificate. And, this is where the User Interface choices made by the Mozilla team are just simply embarrassing. Not unusable, but just really bad.

No user ever cares about these details! It is confusing. Do you think users have issues with URLs? Well what do you think they are going to make of the old outdated Distinguished Names?

Just compare this with the User Experience on the iPhone

Quite a few bug/enhancement reports have been reported on this issue on the Mozilla site. See for example Bug 396441 - Improve SSL client-authentication UI, and my other enhancement requests.

Still this user interface issue should be really easy to fix, as it is just a question of making things simpler, ie. of reducing the complexity of their code. And clearly on a cell phone that should be a priority.

Another issue I can see on the Fennec demo browser, is that I could not find a way to remove the certificates.... That would be quite an important functionality too.

But in any case using foaf+ssl on Fennec is the easiest of all cell phone browsers to use currently - and one of the rare ones, if not the only one, that works correctly! So kudos for that! Fennec and the Nokia N810 is the place to look for what a secure life without passwords, without user names, and a global distributed social network can look like on a mobile platform.

Social Web Bar Camp in Paris

Henry Story — 2009-09-20T04:14:06-07:00

After flying in from Berlin on Friday and celebrating the Jewish new year late into the night with Ori Pekelman, I woke up earlyish on Saturday to go to the Social Web Bar Camp organized in and by La Cantine, the very friendly Parisian conference, community, meeting space for creative people in the digital age.

At 10am the conference started and people slowly arrived for the freely available espresso coffee and pastries. The conference was free too, being sponsored by the member organizations of La Cantine. At 10:20am as the coffee had worked itself into the 60 or more attendees, Ori started the workshop (picture) by having everybody introduce themselves shortly by name and 3 tags. The Bar Camp rules of the game were then explained:

Everybody is a participant
You make the event
Feel free to move between sessions if you feel you are not getting what you were looking for at one of them
Write up your interests on the black board, this will be used to create the time table.

So the sessions were put together on the spot there and then.

Of course I put up a session on foaf+ssl and Distributed Social Networks on the black board, for the session starting at 11am.

After a last coffee, a little over 20 people gathered in the room. I connected the laptop to the projector, introduced myself and the W3C Social Web XG, before starting the presentation (slides in pdf) which I have been giving in various universities and hacker spaces around Europe for the past 5 months. (see the FrOSCon video for example)

A round table discussion of this size has a very different dynamic to conference presentations. It is a lot more free flowing and people can ask question and did as I went through the presentation, leading to lively discussions on security, identity and web architecture. At times it seemed in danger of veering off into widely philosophical discussions, but somehow we always got back to the topic helped by the real implementations of foaf+ssl that are now available. Somehow we did in fact manage to complete covering the subject by 12:30 including an excursion into a description of the very real business opportunities this enables.

From the twitter posts (tagged #swcp) and the invitations to follow up with other French public and private institutions that I got over the course of the day, I can only say that this conference was a great success. I could not have started my 1 month stay in Paris in a better way. I will clearly be very busy during the coming month, before my return to Berlin.

Thanks to Huges M for the photos. More of his pictures are available on his flickr account under the #swcp tag.

Further pointers

Summary in French of the foaf+ssl session
David Larlet's summary "Retours sur le Social Web Camp Paris"
Blog Post by Laurent Enzo: "#swcp l’innovation dans les entreprises, un enjeu de relations publiques ?" on the camp.

RDFa parser for Sesame

Henry Story — 2009-09-09T10:39:42-07:00

RDFa is the microformat-inspired standard for embedding semantic web relations directly into (X)HTML. It is being used more and more widely, and we are starting to have foaf+ssl annotated web pages, such as Alexandre Passant's home page. This is forcing me to update my foaf+ssl Identity Provider to support RDFa.

The problem was that I have been using Sesame as my semweb toolkit, and there is currently was no RDFa parser for it. Luckily I found out that Damian Steer (aka. Shellac) had written a SAX bases rdfa parser for the HP Jena toolkit, which he had put up on the java-rdfa github server. With a bit of help from Damian and the Sesame team, I adapted the code to sesame, create a git fork of the initial project, and uploaded the changes on the bblfish java-rdfa git clone. Currently all but three of the 106 tests pass without problem.

To try this out get git, Linus Torvalds' distributed version control system (read the book), and on a unix system run:

$ git clone  git://github.com/bblfish/java-rdfa.git

This will download the whole history of changes of this project, so you will be able to see how I moved from Shellac's code to the Sesame rdfa parser. You can then parse Alex's home page, by running the following on the command line (thanks a lot to Sands Fish for the Maven tip in his comment to this blog):

$ mvn  exec:java -Dexec.mainClass="rdfa.parse" -Dexec.args="http://apassant.net/"

[snip output of sesame-java-rdfa compilation]

@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix geo: <http://www.geonames.org/ontology/> .
@prefix rel: <http://purl.org/vocab/relationship/> .
@prefix cert: <http://www.w3.org/ns/auth/cert#> .
@prefix rsa: <http://www.w3.org/ns/auth/rsa#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .


<http://apassant.net/> <http://www.w3.org/1999/xhtml/vocab#icon> <http://apassant.net/misc/favicon.ico> ;
        <http://www.w3.org/1999/xhtml/vocab#stylesheet> <http://apassant.net/sites/apassant.net/files/css/css_84042a598208a6aade8783e8c2937a8c.css> , 
                     <http://apassant.net/sites/apassant.net/files/css/css_ba2732162a421c6422a6f5a68742254e.css> .

<http://apassant.net/#id> rdfs:label "About"@en .

<http://apassant.net/alex> a foaf:Person ;
        foaf:name "Alexandre Passant"@en ;
        foaf:workplaceHomepage <http://deri.ie> , 
                               <http://nuigalway.ie> ;
        foaf:schoolHomepage <http://paris-sorbonne.fr> , 
                            <http://dauphine.fr> ;
        foaf:topic_interest <http://dbpedia.org/page/Social_software_%28computer_software%29> ,
                            <http://dbpedia.org/resource/Semantic_Web> ;
        foaf:currentProject <http://www.w3.org/2009/sparql/wiki/> , 
                <http://www.w3.org/2005/Incubator/socialweb/> ;
        <http://purl.org/vocab/bio/0.1/olb> """
\nDr. Alexandre Passant is a postdoctoral researcher at the Digital Enterprise Research Institute, National University
of Ireland, Galway. His research activities focus around the Semantic Web and Social Software: in particular, how these
fields can interact with and benefit from each other in order to provide a socially-enabled machine-readable Web,
leading to new services and paradigms for end-users. Prior to joining DERI, he was a PhD student at Université 
Paris-Sorbonne and carried out applied research work on \"Semantic Web technologies for Enterprise 2.0\" at
Electricité De France. He is the co-author of SIOC, a model to represent the activities of online communities on the
Semantic Web, the author of MOAT, a framework to let people tag their content using Semantic Web technologies, and
is also involved in various related applications as well as standardization activities.\n"""@en ;
        foaf:based_near <http://dbpedia.org/resource/Galway> ;
        geo:locatedIn <http://dbpedia.org/resource/Galway> ;
        rel:spouseOf <http://julie.letierce.net/#id> ;
        foaf:holdsAccount <http://www.flickr.com/people/terraces/> ,
                          <http://www.linkedin.com/pub/alexandre-passant/1/797/1ab> ,
                          <http://last.fm/user/terraces> , 
                          <http://slideshare.net/terraces> , 
                          <http://twitter.com/terraces> .

<http://apassant.net/#cert> a rsa:RSAPublicKey ;
        cert:identity <http://apassant.net/alex> .

_:node14efunnjjx1 cert:decimal "65537"@en .

<http://apassant.net/#cert> rsa:public_exponent _:node14efunnjjx1 .

_:node14efunnjjx2 cert:hex "8af4cb6d6ec004bd28c08d37f63301a3e63ddfb812475c679cf073c4dc7328bd20dadb9654d4fa588f155ca05e7ca61a6898fbace156edb650d2109ecee65e7f93a2a26b3928d3b97feeb7aa062e3767f4fadfcf169a223f4a621583a7f6fd8992f65ef1d17bc42392f2d6831993c49187e8bdba42e5e9a018328de026813a9f"@en .

<http://apassant.net/#cert> rsa:modulus _:node14efunnjjx2 .

[snip]

This graph can then be queried with SPARQL, merged with other graphs, and just as it links to other resources, those can in turn link back to it, and to elements defined therein. As a result Alexandre Passant can then use this in combination with an appropriate X509 certificate to log into foaf+ssl enabled web sites in one click, without needing to either remember a password or a URL.

FrOSCon: the Free and Open Source Conference in Sankt Augustin, Germany

Henry Story — 2009-08-24T09:04:09-07:00

At HAR2009 a couple of people put me in contact with Dries Buytaert, the creator and project lead of Drupal, the famous Open Source content management platform based on php. Dries is leading a very interesting effort aimed at integrating the semantic web stack in Drupal. So I was really happy when he responded to the introduction. He suggested we meet at FrOSCon the Free and Open Source conference located in Sankt Augustin, near Bonn, Germany. I really wanted to stay a bit longer in Amsterdam, but this was just too important an occasion to miss. So I packed up my bag Friday, and after meeting up with Dan Brickley, the co-author of the Foaf ontology who needs no introduction, I caught the last train towards Germany. This turned into a 5 hour trip with 5 changes on slow local trains as those were the only ones I could bring my bicycle onto without first packing it into a box.

[note: this blog uses html5 video tag to view ogg video files, and is best viewed with Firefox 3.5]

Going to FrOSCon turned out to be a very good idea. First of all I met Dries and introduced him quickly to foaf+ssl. It took less than 15 minutes to explain how it worked, for Dries to get himself a foaf certificate on foaf.me and to try it out. If this were made easy to use on Drupal sites, it would be a great way to get some very creative people to help build some cool apps making the most out of distributed social networks...

On Sunday Dries gave a very good keynote "The secrets of building and participating in Open Source communities". Building Open Source communities is not easy, he starts off with, yet it is fundamental to any successful project. He then goes on to elaborate on 6 six themes which from his experience allow a community to thrive and grow:

Time: it takes time to grow a community. Open source communities are always a bit broken, like the internet: there is always something not functioning, but the whole works very well.
Software architecture:
- make the code modular,
- centralise the source code, so that people who contribute modules, and others can find the code
Ecosystem: allow volunteers and commercial organizations to work together. Each has something to bring to the party. Everybody has to be equal. And don't have roadmaps, as they disencourage experimentation and rigidify processes. "Trust, not money is the currency of Open Source"
Tools, Community Design patterns:
- Adoption: easy registration. RSS feeds, documentation
- Identity: profiles, avatars, buddy lists, contacts
- Group support: issue queues, trackers, activity streams, reputation
- Conversations: messaging, comments, forums, blogs, interest groups, planet/aggregator
- Development: CVS/SVN/git/bzr issue queues. release management
Mission: Have a mission that goes beyond the project. In the case of Drupal it is democratizing online publishing. And the core values are
- Be open to Change
- Collaboration
- 100% transparency
- Agile
Leadership: "leadership is not management". Replace planning with coordination (see Clay Shirky's talk "Institution vs collaboration")

Coming from someone with real experience in a very successful project these words are very much worth listening to:

[[If you do not see this video, then your browser does not support the video element available in HTML5, or you don't have an ogg viewer. Download the latest Firefox. I will add links to other codecs as they become available. Otherwise you can view the video on your favorite ogg viewer: download this file]]

Just before the start of Dries' keynote you may have noticed an announcement about a change in the program. The talk on Subversion was canceled due to the inability of the speakers to attend, and it was replaced by a talk on distributed social networks. Yep! During the party the evening before I was told there could be a slot for me to give a talk on foaf+ssl the next day. So on the suggestion of Naxx, an open source grey hat security specialist I had met in Vienna, and who I was surprised to see here again, I spent the whole evening rewriting my slides for Apple Keynote. Naxx spends 3/4 of the year traveling giving talks on security and he had a few hints for me on how to improve my presentation skills. I tried to remember a few of them, and to make sure I did not wave my hands as much as I did at HAR. Here is the result "The Social Web: How to free yourself of your social networks and create a global community:

Please do send me some feedback on how I can improve both my talk and my presentation of it. I may have gone a bit too deeply here into technical details for example, and I should probably have added a section on the business model of distributed social networks. As the last talk of the conference there were only 40 or so attendees, but I was really thankful for the last minute opportunity given to me to present on this topic.

Naxx who helped me work on my presentation skills, gave a very interesting and worrying talk "Malware for Soho Routers: The war has begun", where he showed just how easy it is to hack into everyday home routers and turn them into zombie machines ready to launch an attack on the web. I had always thought that financial incentives would lead large telecoms to make sure that such routers were secure. Not at all it seems. Short term profit motives have led many of them to buy the cheapest machines with the worst possible software (web pages built with shell scripts!) with laughable security. Security may be on the news everyday since September 11 2001, but clearly it was always just a sham. Listen to his talk, and be very worried:

Time either to help out on a open source project for secure routers, or to invest money in a cisco one!

Finally I do have to say that the prize for best presentation (I saw) clearly has to go to Simon Wardley from Canonical, for his funny, entertaining and educational keynote "Cloud Computing". If you have been wondering what this beast is, this will really help:

Well that's it from the FrOSCon, which in german is pronounced FroshCon, "Frosch" being the german for Frog, hence the logo. It was great attending, and I have the feeling of having made a huge leap forward here on my tour.

Camping and Hacking at HAR2009

Henry Story — 2009-08-20T09:15:35-07:00

On Monday 10 August evening I arrived under a light drizzle in Vierhouten in the Netherlands, after cycling the last 100km section of the 300km that I had traveled from the University of Koblenz. I just had time for a beer and a soup, as the c-base bus arrived from Berlin. Night was falling fast, and so we all got together and helped put up the large colorful tent on the edge of a still mostly empty field. The BSD camp next to us had worked out how to get some electricity and kindly let us have enough to power a lamp and a couple of laptops. So we could relax and listen to some music, as it got colder.

I travel very light weight on my bicycle for obvious reasons. So I don't carry a tent with me. Instead I go from hotel, to youth hostel, to family couch. I have not tried the Couch surfing network yet, but it's an extra option I could use. Here on the camp, in the middle of the forest, none of the options were available. So I was very grateful to Dirk Höschen for having taken a nice tent with him for me to sleep in, and also to Rasta for having given me some blankets and furs he happened to have to sleep on. The thick down coat I had carried with me from France, finally came in useful, in the cold nights that followed.

(the tent to the right was the one I slept in)

HAR (Hacking At Random) is an international technology and security conference, with a strong free software, freedom of information political leaning. I had not heard of it until I reached Berlin, but was told so much good about it from so many different people, that I was convinced to go. I was lucky to get some last minute tickets, from some friends of a friend from the Viennese Metalab who could not make it. The 2000 tickets had all been sold out a month ago. Needless to say I had largely missed the deadlines for submitting a presentation. The organisers though were interested enough in what I was presenting on Distributed Social Networks that they gave me a couple of 2 hour workshop sessions to present. The first one of them was filmed, but I am not sure where the video is yet. (I'll update this when I get a link to it.) On Saturday I was lucky to get a 10 minute slot on the Lightening Talks track. This was recorded (slides here)

(( Mhh, one learns a lot from being filmed. I was not so aware how much I gesticulate with my hands. Something I picked up in France I think, but without the french mastery...))

Given how foaf+ssl builds up on X509 and relies on existing Internet infrastructure this conference was an excellent place to come to and learn the latest on holes and limitations in these technologies. Perhaps the most relevant talk was the one given by Dan Kaminsky x509 considered harmful, which he gave while downing a bottle of excellent whiskey - as I found out while talking to him after the presentation.

If you do not see this video, then your browser does not support the video element available in HTML5, or you don't have an ogg viewer. Go rush and download the latest Firefox. I will add links to other codecs as they become available.

In his talk Dan really beats home the importance of DNSSEC, the next version of DNS which is about to get a lot higher profile as the root DNS server moves over to it at the end of this year. The x509 problems could mostly disappear with the rollout of DNSSEC, which is good for me, because it means we can continue working on foaf+ssl. Also foaf+ssl relies a lot less on Certificate Authorities. The only place where that is important is for server authentication (which is where DNSSEC comes in). Client certificates can be self signed as far as foaf+ssl is concerned.

If there was a main theme I got from this conference, then it was clearly the importance of the deployment of DNSSEC. It may be a lot more heavy weight, and a lot more complex than what we have currently, but the problems are getting to be so big, that it is unavoidable. For a good presentation of these issues see Bert Hubert's talk, the man behind PowerDNS:

For an overview/introduction of what DNSSEC is, how it functions and what problems it solves, see Rick Van Rein's presentation Cracking Internet: the urgency of DNSSEC.

Sun Microsystems is also supporting the DNSSEC effort. In this security alert, you can read

Note 1: The above patches implement mitigation strategies within the implementation of the DNS protocol, specifically source port randomization and query ID randomization making BIND 9 more resilient to an attack. It does not, however, completely remove the possibility of exploitation of this issue.

The full resolution is for DNS Security Extensions (DNSSEC) to be implemented Internet-wide. DNS zone administrators should start signing their zones.

If your site's parent DNS zone is not signed you can register with the ISC's DNSSEC Look-aside Validation (DLV) registry at the following URL:

https://secure.isc.org/ops/dlv/

Further details on configuring your DNA zones for DNSSEC is available from the ISC at the following URL:

http://www.isc.org/sw/bind/docs/DNSSEC_in_6_minutes.pdf

The issues addressed by these talks are not just technical, they have political implications for how we live. There were many good talks on the subject here at HAR, but my favorite, perhaps because I followed the story in France so carefully, was the one given by Jéremie Zimmermann co-founder of Quadrature du Net a French site with an English translation, that does an excellent job tracking the position of French and European politicians on issues related to web freedom. Jeremie's talk on Hacking the Law was on Sunday noon, the last day of the talk, and there were some technical problems getting the projectors to work. The best way to get it for the moment is to download it from the command line

curl -o jeremie.ogv ftp://ftp.sickos.org/pub/HAR2009/room1/r1-filer.20090816-115405.ogv

And view in in your favorite ogg viewer. I think the talk starts around the 20th minute.

The talks will hopefully be placed online soon in an easier to access manner.

But HAR2009 was not just about talks. It was also about meeting people, talking, exchanging ideas. Some of the best parties were organised by the Chaos Computer Club a German wide hacker's club that deals with security and political issues, and that is widely referenced by the German media, when in need of enlightenment. They had a great tent with an excellent view of a pond, and at night had excellent DJs to create just the right ambiance to meet people. Mix that together with some Tschunk a cocktail of Club-Mate - the Germanic hacker drink - and Rum, and I found it difficult to go to sleep before 4am.

On Monday morning I cycled the remaining 100km to Amsterdam, one of the most easy going, beautiful towns in Europe, where I am writing this.

Berlin is a funky Zoo

Henry Story — 2009-08-03T10:07:15-07:00

The improbabily drive seems to have been in full swing on Saturday. After getting the second pair of keys for my new Berlin appartment and passing them to my flat mate Alex, I got on my bike and drove towards the Chaos Computer Club some 7 km away. My GPS was running out of batteries, and died completely as I reached the Jannowitzbrücke. As I looked around for directions, I recognized that I was right next to the c-base computer/culture club. So I cycled over, went in, plugged in my GPS into my laptop to recharge, and one thing leading to another got into a number of fun conversations. Amongst others I met Tobias Mathes and introduced him to secure distributed social networks which really seems to be a hit in Berlin.

I asked about how one gets to find a good party, as I had not celebrated my birthday, the date of the move in having coincided with it. There are too many options I was told. "Any party will do" I replied. Tobias invited me to come along to the Arena Sommer Safari party where his favorite DJ was playing. I had no idea what to expect, but was happy to go along as a night-club tourist.

We walked 1km and arrived at street packed full of puffed up, often shaved or crew cut men and their (sometimes fake) blond girl friends. A very unusual group for Berlin. I was told they were mostly from the northern smaller and poorer parts of Berlin. As I collected my €20 ticked we ran into aroemchen, a strong and very friendly Bavarian woman who had an electronic keyboard and a big cardboard star popping out of her backpack. She was the DJ and was herself waiting for her singer elahi. There must have been 5000 to 10000 people trying to get in. Streams of bodies pushing for the large entrance to an old brick building, beer bottles rolling on the floor, people pushing each other forward, backwards, sideways... Avoiding to step onto large muscular tough looking dudes toes. Inside was a huge space with a band playing in the distance. I did not feel like swimming through the crowd onto the packed dance floor, and was content looking at the various characters that turned up, some of them reminding me of the outrageous Backardi advertisment.

Somehow Tobias managed to end up getting a VIP pass for me and I found myself invited up to the stage floor, behind the DJ table, where we sat down after getting a large bottle of water. Tobias took out a Sony camera, and started filming the transition as DJ Aroma took the stage. From that position I was able to see the band spinning and singing 8 meters away, and the crowd dancing to the disco-punk sound released by our two Bavarian friends. I had a few beers and my head was swooning to the beat as I got up to dance to the final Berlin is a funky zoo.

The Zoo is not as bad as it used to be
It is only very funky since the 90ies
A lot of different species can be found
       come round
  stay for a while or longer
share their food and their behavior.
Try to get a little smoother
And though there's not a lot of luxury in our crew
It's ok to stay for me and you
because it's wild and funky in our Zoo
(Wild and funky in our zoo)

Berlin is a funky Zoo
Berlin is a funky Zoo
Berlin is a funky Zoo
yea Berlin *is*  *a* funky Zoo!

The teddy bears from Schöneberg
It loves to run in underwear
The beary is gay and never gray
he likes to stay the nights away

The monkeys in the Blue 8 Bar
in Herman platz which is quite far
The bar is far but not beyond
there's food around and drinks along

The drink is not beer but iron here
And TV says its weird here
But the mix is the mix, it's just the truth
Just like nature in the Zoo
 
Berlin is a funky Zoo
Berlin is a funky Zoo
Berlin is a funky Zoo
yea Berlin *is*  *a* funky Zoo!

Chuck is selling hemp or chicken
playing games and being tricky
Oh such lovely food here for the bear
but only with the propper gang wear

proper lease the penguin
looking like on heroin
spending weekends at the ranch
searching fish at minimal trance

you also find the panda bear
without bamboo but dancing square
in the black colcolgova 
which is not just very far

but in Kreuzberg and in Hein
another spot for hogs and swine
being naked like the fish
the old sweaty berlinish

Berlin is a funky Zoo
Berlin is a funky Zoo
Berlin is a funky Zoo
yea Berlin *is*  *a* funky Zoo!

The bearfoot ? is in the park
Dancing somedays till it's dark
No one watching and the groups
perfect playground lovely fos (?)

The bear lives in this funky zoo
just at times its like a loo
At other times it's cool and fresh
It's seduction and its fresh

the bear is heavy ego-tying(?)
living in this crazy shrine
He loves to dance just like you
cause Berlin is a funky zoo

Berlin is a funky Zoo
Berlin is a funky Zoo
Berlin is a funky Zoo
yea Berlin *is*  *a* funky Zoo!

Next thing I was watching the sun rise over Berlin.

Saving Face: The Privacy Architecture of Facebook

Henry Story — 2009-07-25T09:32:36-07:00

In his very interesting thesis draft Saving Face: The Privacy Architecture of Facebook, Chris Peterson, describes through a number of real life stories some very subtle and interesting issues concerning privacy and context that arose during the rapid evolution of the now 250 million member social network.

Perhaps the most revealing of these stories is that of Junior High School student Rachel who broadcast the following distress status message my grandmother just friend requested me. no Facebook, you have gone too far! Chris Peterson develops: Rachel and her grandmother are close. She trusts her grandmother. She confides in her grandmother. She tells her grandmother "private" things. She is certainly closer to her grandmother than many of her Facebook Friends. So what's the big deal? Rachel explains:

Facebook started off as basically an online directory of COLLEGE STUDENTS. I couldn't wait until I had my college email so that I could set up an account of my own, since no other emails would give you access to the site. Now, that was great. One could [meet] classmates online or stay in touch with high school mates [but it] has become a place, no longer for college students, but for anyone. [About] five days ago, the worst possible Facebook scenario occurred, so bizarre that it hadn't even crossed my mind as possible. MY GRANDMOTHER!? How did she get onto facebook?...As my mouse hovered between the accept and decline button, images flashed through my mind of sweet Grandma [seeing] me drinking from an ice luge, tossing ping pong balls into solo cups full of beer, and countless pictures of drunken laughter, eyes half closed. Disgraceful, I know, but these are good memories to me. To her, the picture of my perfectly angelic self, studying hard away at school, would be shattered forever.

The paper is full of legally much more serious stories, but this one is especially revealing as it makes apparent how the flat friendship relation on Facebook does not take into account the context of the relationship. Not all frienships are equal. Most people have only very few friends they can tell everything to. And most often one tells very different stories to different groups of friends. In the physical world we intuitively understand how to behave in different contexts. One behaves one way in church, another in the bar, and yet another way in front of one's teachers, or parents. The context in real life is set by the architecture of the space we are in (something Peter Sloterdijk develops at length in his philosophical trilogy Spheres). The space in which we are speaking and the distance others have to us guides us in what we should say, and how loud we can say it. On Facebook all your friends get to see everything you say.

It turns out that it is possible to create an equivalent contextual space on Facebook using a little know and recently added feature, which allows one to build groups of friends and specify access control policies on posts per group. Chris shows clearly that this by itself is not enough: it requires a much more thorough embedding in the User Interface so that the intuitive feel one has in real life for who hears what and to whom one is speaking is available with the same clarity in the digital space. In the later part of the thesis Chris explores what such a User Interface would need to do to enable a similarly intuitive notion of space to be available.

Applications to the Social Web

One serious element of the privacy architecture of Facebook (and other similar social networks) not covered by this thesis, yet that has a very serious impact in a very large number of domains, is the constant presence of a third party in the room: Facebook itself. Whatever you say on these Social Networks, is visible not only to your group of friends, but also to Facebook itself, and indirectly to its advertisers. Communicating in Facebook puts one then in a similar frame of mind to what people in the middle ages would have been in, when mankind was under the constant, omnipotent and omniscient presence of God who could read every thought, even the most personal. Except that this God is incorporated and has a stock market value fluctuating daily.

For those who wish to escape such an omni-presence yet reap the benefits of online electronic communication, the only solution lies in the development of distributed secure social networks, of a Social Web where every body could own what they say and control who sees it. It turns out that this is possible with semantic web technologies such as foaf and access control mechanisms based on ssl.

One very positive element I take from this thesis is that the minimal technical building blocks for reconstituting a sense of context is the notion of a group and access control of resources. In a the Social Web we should be able to reconstitute this using the foaf:Group class and foaf+ssl for access control. On this basis Chris Peterson's user interface suggestions should be applicable in a distributed social network.

All in all then I found this thesis to be very rewarding and a very interesting read. I recommend it to all people interested in the Social Web.

How to write a simple foaf+ssl authentication servlet

Henry Story — 2009-07-24T01:23:53-07:00

After having set up a web server so that it listens to an https socket that accepts certificates signed by any Certification Authority (CA) (see the Tomcat post), we can write a servlet that uses these retrieved certificates to authenticate the user. I will detail one simple way of doing this here.

Retrieving the certificate from the servlet

In Tomcat compatible servlets it is possible to retrieve the certificates used in a connection with the following code:

import java.security.cert.X509Certificate;
protected void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
       //...
       X509Certificate[] certificates = (X509Certificate[]) request
                       .getAttribute("javax.servlet.request.X509Certificate");
       //...
 }

Verifying the WebId

This can be done very easily by using a class such as DereferencingFoafSslVerifier (see source), available as a maven project from so(m)mer repository (in the foafssl/ directory).

Use it like this:


  Collection<? extends FoafSslPrincipal> verifiedWebIDs = null;

  try {
     FoafSslVerifier FOAF_SSL_VERIFIER = new DereferencingFoafSslVerifier();
     verifiedWebIDs = FOAF_SSL_VERIFIER.verifyFoafSslCertificate(foafSslCertificate);
  } catch (Exception e) {
     redirect(response,...); //redirect appropriately
     return;
  }

If the certificate is authenticated by the WebId, you will then end up with a collection of FoafSslPrincipals, which can be used for as an identifier for the user who just logged in. Otherwise you should redirect the user to a page enabling him to login with either OpenId, or the usual username/password pair, or point him to a page such as this one where he can get a foaf+ssl certificate.

For a complete example application that uses this code, have a look at the Identity Provider Servlet, which is running at https://foafssl.org/srv/idp (note this servlet was trying to create a workaround for an iPhone bug. Ignore that code for the moment).

Todo

The current library is too simple and has a few gaping usability holes. Some of the most evident are:

No support for rdfa or turtle formats.
The Sesame RDF framework/database should be run as a service, so that it can be queried directly by the servlet. Currently the data gathered by the foaf file is lost as soon as the FOAF_SSL_VERIFIER.verifyFoafSslCertificate(foafSslCertificate); method returns. This is ok for a Identity Provider Servlet, but not for most other servers. A Java/RDF mapper such as the So(m)mer mapper would then make it easy for Java programmers to use the information in the database to personalize the site with the information given by the foaf file.
develop an access control library that makes it easy to specify which resources can be accessed by which groups of users, specified declaratively. It would be useful for example to be able to specify that a number of resources can be accessed by friends of someone, or friends of friends of someone, or family members, ....

But this is good enough to get going. If you have suggestions on the best way to architect some of these improvements so that we have a more flexible and powerful library, please contact me. I welcome all contributions. :-)

How to setup Tomcat as a foaf+ssl server

Henry Story — 2009-07-23T09:25:23-07:00

foaf+ssl is a standards based protocol enabling one click identification/authentication to web sites, without requiring the user to enter either a username or a password. It can be used as a global distributed access control mechanism. It works with current browsers. It is RESTful, thereby working with Linked Data and especially linked foaf files, enabling thereby distributed social networks.

I will show here what is needed to get foaf+ssl working for Tomcat 6x. The general principles are documented on the Tomcat ssl howto page, which should be used for detailed reference. Here I will document the precise setup needed for foaf+ssl. If you want to play with this protocol quickly without bothering with this procedure I recommend using the foaf+ssl Identity Provider service which you can point to on your web pages, and which will then redirect your users to the service of your choosing with the URLEncoded WebId of your visitor.

foaf+ssl works by having the server request a client certificate on an https connection. The server therefore needs an https end point which can be specified in Tomcat by adding the following connector to the conf/server.xml file:

<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
           maxThreads="50" scheme="https" secure="true"
           sslProtocol="TLS"/>

Note: the default https port is 443, but it requires root privileges.

Servers authentify themselves by sending the client a certificate signed by a well known Certificate Authority (CA) whose public key is shipped in all browsers. Browsers use the public key to verify the signature sent by the server. If the server sends a certificate that is not signed by one of these CAs (perhaps it is self signed) then the web browser will usually display some pretty ugly error message, warning the user to stay clear of that site, with some complex way of bypassing the warning, which if the user is courageous and knowledgeable enough will allow him to add the certificate to a list of trusted certs. This warning will put most people off. It is best therefore to buy a CA certified cert.(I found one for €15 at trustico.) Usually the CA's will have very detailed instructions for installing the cert for a wide range of servers. In the case of Tomcat you will end up with the following addition property values:


<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
           maxThreads="50" scheme="https" secure="true"
           keystoreFile="conf/yourServerCert.kdb" 
               keystoreType="JKS" keystorePass="changeme" 
           sslProtocol="TLS"/>

And of course this requires placing the server cert file at the keystoreFile path.

There are usually two ways for the server to respond to the client not sending a (valid) certificate. Either it can simply fail, or it can allow the server app to decide what to do. Automatic failure is not a good option, especially for a login service, as the user will then be confronted with a blank page. Much better is to allow the server to redirect the user to another page explaining how to get a certificate and giving him the option of authentication using OpenId or simply the well known username/password pattern. To enable Tomcat to respond this way you need to add the clientAuth="want" attribute value pair:


<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
           maxThreads="50" scheme="https" secure="true"
           keystoreFile="conf/yourServerCert.kdb" 
               keystoreType="JKS" keystorePass="changeme" 
           sslProtocol="TLS" clientAuth="want" />

Most Java Web Servers on receiving a client certificate, attempt to automatically validate it, by verifying that it is correctly signed by one of the CA's shipped with the Java Runtime Environment (JRE), verifying that the cert is still valid, ... As the SSL library that ships with the JRE does not implement foaf+ssl we will need to do the authentication at the application layer. We therefore need to bypass the SSL Implementation. To do this Bruno Harbulot put together the JSSLUtils library available on Google Code. As mentioned in the JSSLUtils Tomcat documentation page this will require you to place two jars in the Tomcat lib directory: jsslutils-0.5.1.jar and jsslutils-extra-apachetomcat6-0.5.2.jar (the version numbers may differ as the library evolves). You will also need to specify the SSLImplementation in the conf file as follows:


<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
           maxThreads="50" scheme="https" secure="true"
           keystoreFile="conf/yourServerCert.kdb" 
               keystoreType="JKS" keystorePass="changeme" 
           SSLImplementation="org.jsslutils.extra.apachetomcat6.JSSLutilsImplementation" 
           sslProtocol="TLS" clientAuth="want" />

Usually servers send in the request to the client a list of Distinguished Names of certificates authorities (CA) they trust, so that the client can filter from the certificates available in the browser those that match. Getting client certificates signed by CA's is a complex and expensive procedure, which in part explains why requesting client certificates is very rarely used: very few people have certificates signed by well known CAs. Instead those services that rely on client certificate tend to sign those certificates themselves, becoming their own CA. This means that certificates end up being valid for only one domain. foaf+ssl bypasses this problem by accepting certificates signed by any CA, going so far as to allow even self signed certs. The server must therefore send an empty list of CAs meaning that the browser can send any certificate (TLS 1.1). With the JSSLutils library available to Tomcat, this is specified in the conf/server.xml file with the acceptAnyCert=true attribute.


<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
           maxThreads="50" scheme="https" secure="true"
           keystoreFile="conf/yourServerCert.kdb" 
               keystoreType="JKS" keystorePass="changeme" 
           SSLImplementation="org.jsslutils.extra.apachetomcat6.JSSLutilsImplementation"
           acceptAnyCert="true" sslProtocol="TLS" clientAuth="want" />

At this point you have set up your Apache Server correctly. A user that arrives at your SSL endpoint and that has a couple of certificates will be asked to choose between them. Your client code can the extract the certificate with the following code:


       X509Certificate[] certificates = (X509Certificate[]) request
                       .getAttribute("javax.servlet.request.X509Certificate");

You can use these certificates then to extract the WebId, and verify the SSL certificates. I will write more about how to do this in my next blog post.

two months of foaf+ssl talks

Henry Story — 2009-07-20T08:16:53-07:00

For the past one and a half months I have been traveling through Europe giving talks on foaf+ssl, the RESTful authentication protocol for the Social Web. Here is a short summary of where I have been.

18 May 2009, Salzburg Research: On my way cycling from Fontainebleau to Vienna, I stopped by in Salzburg, Austria, where the offices of the organisers of the EU sponsored KIWI (Knowledge in a Wiki) project, which Sun is participating in, are located. I introduced the group there to foaf+ssl, and they are now working on an implementation for their award winning semantic wiki.
20 May 2009, Semantic Web Company: Right after arriving in Vienna, I met up with Andreas Blumauer, editor of the recently published Springer Book "Social Semantic Web". Hopefully my presentation will make its way in some form or another into the next edition :-). Andreas also gave me an overview of the powerful yet easy to use thesaurus management system named Pool Party, they are developing.
1 May 2009, European Semantic Web Conference, Heraklion: Ian Jacobi who had come to Crete for the occasion, helped me present the paper FOAF+SSL: RESTful Authentication for the Social Web in the SPOT track. The other papers presented in that track all fitted together very well, giving a very good overview of the topics that need to be covered in this space. I will be rereading them soon. The ESWC conference was also a great opportunity to do a number of quick one to one presentations by demoing it working on the iPhone. ( Sadly the latest OS release broke the SSL stack, making my iPhone so much less useful )
18 June, Vienna University of Technology: In Crete I met Christoph Grün who helped organize a slot to present at the Institute of Software Technology & Interactive Systems. Christoph is working on Online Tourism web services, which would be a great use case for foaf+ssl. Imagine a group of people deciding to organize an outing on a tourism wiki site, where all members of the group would get access to that outing after a simple drag and drop of a foaf:Group URL onto the outing project console.... No account setup required.
23 June, Metalab Hacker's Club, Vienna: While in Vienna I gave a presentation at the Metalab, an open meeting space for hackers of all walks of life. As it happened a journalist from the well known French newspaper "Le Monde" happened to be present and wrote up an article "Les nouvelles tribus du Net" (now paying) on the lab, mentioning my presentation en passant.
2-3 July, Sun Microsystems Kiwi Meeting, Prague: The Kiwi group met in Prague for a couple of days to synchronize their work. After having won the best semantic web application prize at the European Semantic Web Conference in Crete, the mood was very positive. This was a good place to introduce the rest of the group to the potential of foaf+ssl, which is currently being implemented in Kiwi by Stefanie Stroka.
13 July, University of Leipzig: I spent a whole day with the excellent Agile Knowledge Engineering and Semantic Web team at the University of Leipzig. After an update on their latest work with DBPedia, Ontowiki, xOperator, ... I presented foaf+ssl. After lunch we then spent the afternoon on a very helpful hands on session. There are still enough rough edges in the different implementations of foaf+ssl that a bit of guidance can save a lot of time. End result, a few days later Sebastian Dietzold notified me that Philipp Frischmuth had written a first implementation available publicly at http://trunk.ontowiki.net/. During our session we also discovered a bug on http://foaf.me/, which was soon fixed.
15 July, University of Potsdam: Hagen organised a very well attended meeting at the University of Potsdam. The questions following the talk were very good, and showed a large interest. Sadly we did not have time for a hands on session, as my next meeting was just a few hours later. Hands on sessions are still very important, as they help turn a talk into an experience. It helps a lot that Melvin Carvalho enhanced foaf.me to make it very easy to create both a foaf file and a linked certificate, so with time these hands on sessions should be easier and shorter to do.
15 July, New Thinking Store, Berlin: I finished the day with a presentation at the New Thinking Store in Berlin, organized by Martin Schmidt. This was an opportunity again to present to Web 2.0 and more directly practical people.

The foaf+ssl world tour

Henry Story — 2009-06-11T03:21:01-07:00

As you can see from the map here I have been cycling from Fontainebleau to Vienna (covering close to 1000km of road), and now around Cyprus in my spare time. On different occasions along my journey I had the occasion to present foaf+ssl and combine it with a hands on session, where members of the audience were encouraged to create their own foaf file and certificates, and also start looking into what it takes to develop foaf+ssl enabled services. This seems like a very good way to proceed: it helps people get some hands on experience which they can then hopefully pass on to others, it helps me prioritize what need to be done next, and should also lead to the development of foaf+ssl services that will increase the network value of the community, creating I hope a viral effect.

I started this cycle tour in order to loose some weight. I still have 10kg to loose or so, which at the rate of 3kg per 1000km will require me to cycle another 3000km. So that should enable me to visit quite a few places yet. I will be flying back to Vienna where I will stay 10 days or so, after which I will cycle to Prague for a Kiwi meeting on the 3rd of July. After that I could cycle on to Berlin. But really it's up to you to decide. If you know a good hacker group that I can present to and cycle to, let me know, and I'll see how I can fit it into my timetable. So please get in contact! :-)

Link Roundup for Friday 29 May 2009

Henry Story — 2009-05-29T11:33:38-07:00

Linked Data is getting a lot of press:

Linking Data and Semantics at O’Reilly is a very interesting article that shows how some developers at O'Reilly Media, the famous computer book publisher, moved from ad hoc XML formats published with complex scripts to RESTful publication, and then found themselves unable but to start using the benefits brought by linked data and the semantic web, thereby simplifying a lot of their data issues. Great progress.
Price Waterhouse Coopers just published a bullish 58 page Technology forecast for the Semantic Web containing a lot of very good articles. download for free here

On a the Social Web front:

I added 5 simple use cases for the Social Web, which foaf+ssl can take care of on the Social Web XG wiki.
Bruno Harbulot tagged release 0.3.1 for the FOAF+SSL java libraries and release maven jars for them, as explained in his e-mail to the list

There is a new project called Interactive Knowledge Stack (IKS), which is a Semantics Based Open Source platform for Small to Medium CMS Providers.