my cup of [T]

How to get a job with Microsoft, Apple or Google

2012-02-08T15:41:00.001-08:00

I recently read a very interesting article about how to get yourself noticed in the “Major Leagues” . The article is by Gayle Laakmann McDowell, who herself has worked at four of today’s big tech companies the likes of Apple, Google and Microsoft.
Here is a short version of the 9 Reasons.

Go to an elite school (or associate with one).
Intern early, and relevant to your career (knowing how to flip burgers doesn’t make you a better coder).
Major in something relevant.
Community service means: do Tech work for free, not in a soup kitchen.
Learn how to write (oops, that is why I could never land one of those ).
Be a teacher’s pet. They write good recommendation letters.
Be a generalist.
Be an entrepreneur, innovate or deliver results.
no one cares if you have a 4.0 GPA.

At the end of the day, make sure that whatever you do is transferable to the next step/job in your career.

MSDN Training Courses

2011-12-30T09:37:00.001-08:00

Microsoft’s DPE Team has put together some great training courses available for download. It is always good to “sharpen the tools”, and this would be a great starting point for learning a new skill or sharpen the already developed one.

Some of the ones that caught my eye are:

Link to Training Courses: http://msdn.microsoft.com/en-us/gg299335

Windows Identity Foundation Training available

2011-12-21T09:29:00.001-08:00

[Federated] Security is no easy thing, let’s just state that out of the gate. That is why our Federated Security guru Dominick Baier has put together a two-day course. You can get some more details over here.

Walk-through of provisioning Identity Server v1.0

2011-12-19T08:12:00.001-08:00

Introduction

If you have the need to use your own Identity Provider, and want to go with something light (i.e.: not ADFS), Thinktecture’s Identity Server is your product. I have been using it for the last couple of months and I love it!! I actually added a service layer over it to enable my RP to provision users in the Identity Server (yes, I know that this is contrary to the general concept of outsourcing Identity Management, but in my scenario, trust me, it makes sense).
From the CodePlex site:

Thinktecture IdentityServer is an open source security token service based on Microsoft .NET, ASP.NET MVC, WCF and WIF.
High level features
Multiple protocols support (WS-Trust, WS-Federation, OAuth2, WRAP, JSNotify, HTTP GET)
Multiple token support (SAML 1.1/2.0, SWT)
Out of the box integration with ASP.NET membership, roles and profile
Support for username/password and client certificates authentication
Support for WS-Federation metadata
Support for WS-Trust identity delegation
Extensibility points to customize configuration and user management handling

Setup

UPDATE: This walk-through assumes you are setting up Identity Server in a production/QA environment, and not as a single machine/developer setup. Hence why we are setting up by using SQL Server instead of mounting the Compact database included in the App_Data directory, as well as installing the ASP.NET Membership provider DB on the DB Server.

Download source from here
Unzip the file and open the solution.
Because Identity Server (IdSvr) needs an ASP.NET membership database, we are going to set one up (if it doesn’t exist). There are some great tutorials on the web on how to do this (if you don’t already know), here is one of them.
After having installed the ASP.NET Membership database, we are going to update the connection string in IdSvr to point to said database.
The connection string file is located at \Configuration\connectionstring.config (Below is an example)

   1:  <connectionStrings>

   2:    <add name="ProviderDB"

   3:         connectionString="Persist Security Info=False;

   4:         User ID=sa;

   5:         password=****;

   6:         Initial Catalog=aspnetdb;

   7:         Data Source=mydbserver;"

   8:         providerName="System.Data.SqlClient" />

9:

>

To test that the connection string works, in Solution Explorer, you should select the Website project, then from Visual Studio’s menu, select Project –> ASP.NET Configuration. This will launch the ASP.NET Web Site Administration Tool.

Using the ASP.NET Web Site Administration Tool, proceed to create a user (i.e.: Administrator) and a roles called IdentityServerAdministrators and IdentityServerUsers. These roles are important because they allow the user created to logon to IdSvr’s administration screen, and in the case of IdentityServerUsers, to be forwarded to the RPs upon successful login. These roles are specified in the Constants.cs file inside of the Thinktecture.IdentityServer.Core project.

   1:   public static class Constants

   2:      {

   3:         // ....

   4:          public static class Roles

   5:          {

   6:              public const string InternalRolesPrefix          = "IdentityServer";

   7:              public const string Users                        = "Users";

   8:              public const string Administrators               = "Administrators";

9:

  10:              public const string IdentityServerUsers          = InternalRolesPrefix + Users;

  11:              public const string IdentityServerAdministrators = InternalRolesPrefix + Administrators;

  12:          }

Configuring IIS 7

Let’s proceed to configure IIS 7 to host the Identity Server website. We will need to:

Request a Certificate for SSL (self-signed, Domain cert or commercial). Read this tutorial
Setup https bindings. Go to this link, and scroll down to Create an SSL Binding.

Creating a certificate for Token Signing

The process of creating this certificate is the same as requesting a certificate for SSL. Why not just the SSL Certificate then? – May you ask?–, and the answer is:

“Using the SSL certificate for the token signing certificate will work – but this should not be the configuration you use in production. This is considered bad key hygiene.”

Source:Technet

In my case, I have requested two certificates to the Domain Certificate Authority.

***UPDATE: Make sure the certificate Distinguished Name of each certificate is different (i.e.: Don’t request two certificates with the same attributes). I ran into an issue where IdentityServer’s x509Certificate Helper could not find the right certificate because there were two certificates, and it didn’t like that.

var certs = store.Certificates.Find(findType, value, false);
 if (certs.Count != 1) 
 { 
     throw new InvalidOperationException(String.Format("Certificate not found: {0}", value));  
 }

We are almost there.

Configuring Identity Server

You should be able to navigate to Identity Server’s URL. If the certificates you created are not trusted by your computer, you see this screen. This occurs if you are using a certificate issued by a CA your computer does not trust. Here is a link on how to trust the certificate.

You should be seeing Identity Server’s initial configuration screen. Go ahead and customize the first two fields to match your environment, and select the certificate that will be used for token signing.

Tada!! You have successfully configured Identity Server and should be ready to add your application as a Relaying Party (RP). You can find a tutorial on how to do that over here (scroll down to 2.Register an existing production STS).

CMAP CodeCamp Slide Deck

2011-11-13T17:41:00.001-08:00

Wow!! What an awesome experience to have participated in CMAP's CodeCamp.
I have started the process of going from having a wealth of opinion and a lack of experience, to a more balanced mix. I have made a mental note of a myriad of things that need to be improved, and will continue to improve the talk and gain more experience every time I do it.
Thanks to the audience for being so patient with me and not have walked out on me. The slides are here.

Speaking at CMAP's Fall Code Camp

2011-11-04T06:45:00.001-07:00

It is official. I will be speaking at a local CodeCamp about Windows Identity Foundation. There are many interesting talks and the best part is that is all free. Check it out and do not miss it.

The Central Maryland Association of .NET Professionals (CMAP) is holding its Fall 2011 Code Camp on Saturday, November 12th, 2011 at the Loyola University Maryland Graduate Center in Columbia, MD.
The Code Camp will run from 8:30am - 5:30pm with 20-25 awesome sessions covering a wide range of database, software and portal development topics. It's totally free. No gimmicks. No sales pitches. Enjoy breakfast and lunch at no charge while you mingle with your peers.

For more details click here

We will remember you Steve

2011-10-05T17:57:00.000-07:00

Steve Jobs will always be in my mind. He was indeed an influential person in my life, an inspiration and a role model. He was living proof that you can create your own destiny, without worriying too much about the path society expects you to follow to be defined as successful.

"Your time is limited, so don't waste it living someone else's life. Don't be trapped by dogma - which is living with the results of other people's thinking. Don't let the noise of other's opinions drown out your own inner voice. And most important, have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary." - Steve Jobs

Setting up Thinktecture’s Identity Server

2011-09-28T19:07:00.000-07:00

The following tutorial assumes the reader is familiar with the following technologies/concepts:

Single Sign-on (SSO)
Windows Identity Foundation (WIF)
Active Directory Federation Services
Claims-based identity

This post is a how to setup Thinktecture’s ~~StarterSTS~~ Identity Server [B1].

1. Download the Source Code from the Codeplex site [at the time of this writing, the current version is B1 Refresh] and unzip it on your local drive.

2) Once the Solution is opened in Visual Studio, inside of the Tools solution folder you will find a Setup project. Run the project by right clicking on it, Selecting Debug –> Start new instance.

3) Set the Location of the Configuration Database as shown below.

You can find the file called IdentityServerConfiguration.sdf inside of the App_Data folder of the Website Project.

4) Select the certificate that will be used for SSL Encryption. **Note: If you already have IIS setup with SSL, you most definitely want to use the same certificate. I suspect you will, because if you are installing this Identity Server you must be very familiar with the Windows Identity Foundation configuration dance.

5) Select the certificate that will be used for Signing (You can use the same certificate)

After this is done, you might be thinking that you can run the [website] project now and it should just work, right? Thought WRONG! There is no free meal in this world. Our friend Dominick [Baier] has had this running on his machine for a while, so perhaps forgot about setting up IIS, the ASP.NET provider Database and all that business.

SEtting up ThE WEBSITE PROJECT TO USE IIS

So, right after you download the source code, the Web Project Properties looks like so:

Notice the “[X] Use Custom Web Server” option is selected, and points to https://roadie/idsrv/. You want to change these setting as follows:

Switch the setting to Use Local IIS Web Server and enter a more appropriate URL (i.e.:http://[your machine’s fully qualified name]/idsrv), or if you are one cool cat, you may choose Use IIS Express (but then, you are on your own).

We are almost there, do not despair.

CONFIGURING THE ASP.NET MEMBERSHIP DB.

If you were to try to run the Website, you should get this “Yellow page of death”. And that is due to the fact (if you are one of those who do no read error pages) that the 1) you have not installed the standard ASP.NET Membership schema, and 2) the Identity under which IIS is running does not have access to said database (provided it existed). Follow these instructions to setup the ASP.NET application services schema.

After having installed the ASP.NET Schema on your SQL Server instance, go to SQL Server Management Studio, and under Security –> Logins, and make sure that the Identity under which your IIS Application Pool is running has a valid login in SQL Server and has the right access to the ASP.NET database. In my case, the App pool Identity is 'IIS APPPOOL\DefaultAppPool' and the database named "aspnetdb".

Lastly, change the Website\Configuration\connectionStrings.config file to point to your ASP.NET application services database.

<connectionStrings>
<add name="ProviderDB"
connectionString="data source=.\sqlexpress;Integrated Security=SSPI;Initial Catalog=aspnetdb"
providerName="System.Data.SqlClient" />
<add name="IdentityServerConfigurationEntities"
connectionString="metadata=res://Thinktecture.IdentityServer.Core/Repositories.SqlCompact.IdentityServerConfiguration.csdl|res://Thinktecture.IdentityServer.Core/Repositories.SqlCompact.IdentityServerConfiguration.ssdl|res://Thinktecture.IdentityServer.Core/Repositories.SqlCompact.IdentityServerConfiguration.msl;provider=System.Data.SqlServerCe.4.0;provider connection string=&quot;Data Source=|DataDirectory|\IdentityServerConfiguration.sdf&quot;"
providerName="System.Data.EntityClient" />
</connectionStrings>

If you did everything right, you should now be able to run the application and get this page.

Accessing the Administration Mode of Identity Server

Out of the box, IdentityServer is configured to use the SqlMembershipProvider membership provider implementation. Therefore to login you have to:

create a user (i.e.: Administrator)
create a role called IdentityServerAdministrators.

Both of these can be accomplished by using the built-in Web Site Administration Tool (in Visual Studio, go to Project –> ASP.NET Configuration).

[FYI] Contrary to what Dominik Baier’s introductory video says [9:02] , the role the code is expecting is not “TokenServiceAdministrators”, but instead, IdentityServerAdministrators).

[Change for Improvement] This can be improved in the future by modifying the provided implementation of ClaimsAuthorizationManager, and changing the AuthorizeAdministration Method (inside of Thinktecture.IdentityServer.Web.Security.AuthorizationManager)

protected virtual bool AuthorizeAdministration(Collection<Claim> resource, IClaimsIdentity id)
{
return (id.ClaimExists(ClaimTypes.Role, Constants.Roles.IdentityServerAdministrators));
}

The next article will describe how to create a configure your application (Relaying Party) to trust Identity Server as an Secure Token Service (STS).

Where my data files at!?

2011-09-01T08:24:00.001-07:00

A bit of context: As part of my team’s development workflow, we create/modify our Domain Model in code (entities such as Customer, Product, Order, etc.) and then generate the Database Model via a homegrown console app. This allows us to [efficiently] code our Domain Model without having to worry about applying these changes to the lower layers of the system all the way to the database schema.

The [Schema Export] console app I mentioned automatically generates a fresh database by exploring our Domain Model – NHibernate makes this very easy - for the purpose of comparing and synchronizing with the Database Project , thus bringing our Persistence store up-to-date with our Domain Model.

The Problem: I had a need to find out the physical path was the instance of SQL Server installed on the server [c:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\] and thus were the data files for the database are placed [$SqlInstallPath\MSSQL\Data\].

The Solution:

The following T-SQL returned the path where the master database is located:

select physical_name from master.sys.databases dbs inner join master.sys.master_files files on dbs.database_id = files.database_id
where dbs.name = 'master' and type_desc = 'ROWS'

Results:

physical_name
-------------------------------------------------------------------------------
c:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\master.mdf
(1 row(s) affected)

And the following function takes care of removing the filename and fiving you the path:

 private static string GetDbFilePath ( SqlConnection sqlConnection, string databaseName )
        {
            string path = string.Empty;
            try
            {
                string datafilepathQuery =
                    string.Format (
                        @"select physical_name from 
              master.sys.databases dbs inner join master.sys.master_files files 
                on dbs.database_id = files.database_id
                where dbs.name = '{0}' and type_desc = 'ROWS'", databaseName );
                using ( var sqlCmd = new SqlCommand ( datafilepathQuery, sqlConnection ) )
                {
                    object datafilepath = sqlCmd.ExecuteScalar ();
                    path = datafilepath.ToString ();
                    path = path.Substring(0, path.LastIndexOf('\\'));
                }
            }
            catch ( Exception )
            {
            }
            return path;
        }

This allowed me to subsequently run another command to create the database schema at the right location. That is all for today folks!

FYI: I will be writing a post – or series of posts – on how to improve your development workflow and thus adhering to my favorite tenet of the Agile Manifesto : “maximizing the amount of work not done”.

Getting rid of Literal strings - part 1

2011-06-22T06:36:00.000-07:00

In my travels around MVVM Land (specially as seen on MSFT tutorials around the net), it is commonplace to find string literals being used when implementing the INotifyPropertyChanged, to specify the property name (as shown in the code below).

  1:     public class Customer : INotifyPropertyChanged
  2:     {
  3:         private string _firstName;
  4: 
  5:         public string FirstName
  6:         {
  7:             get { return _firstName; }
  8: 
  9:             set
 10:             {
 11:                 _firstName = value;
 12:                 PropertyChanged(this, new PropertyChangedEventArgs("FirstName"));
 13:             }
 14:         }
 15: 
 16:         #region INotifyPropertyChanged Members
 17: 
 18:         public event PropertyChangedEventHandler PropertyChanged;
 19: 
 20:         #endregion
 21:     }

But excessive use of the Copy + Paste “design pattern”, can be error prone – often times when Copying + Pasting, I forget to change the string to the new property name, and/or misspell the intended name - causing your ViewModels not to work correctly.

Solution: The guys at Microsoft Patterns & Practices have included some nice "lifestyle enhancing” features in Prism that make your everyday coding much enjoyable. One of those features is the NotificationObject, an abstract class that implements the INotifyPropertyChanged (INPC) interface, and allows you to write code such as this:

  1: public class Customer : NotificationObject
  2:     {
  3:         private string _firstName;
  4: 
  5:         public string FirstName
  6:         {
  7:             get { return _firstName; }
  8: 
  9:             set
 10:             {
 11:                 _firstName = value;
 12:                 RaisePropertyChanged(() => FirstName);
 13:             }
 14:         }
 15:     }

Notice that Line 12 does not use a “Magic String”, but rather a lambda expression that points to the property. This gives you compile-time checking as well as refactoring with ease. some improvements could be made (i.e.: Only raising the Property Changed event when the value changes), but I will leave that up to you.

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