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An ASP.NET Framework for Human Interactive Proofs

An article I recently wrote for MSDN online just went live:
An ASP.NET Framework for Human Interactive Proofs

It's always fun when that happens :)

Published Thursday, September 23, 2004 5:36 PM by toub
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Thursday, September 23, 2004 6:24 PM by Scott Galloway's Personal Blog

# Great post on 'Human Interactive proofs' or those screwy letter things where you have to type in some letters...

Thursday, September 23, 2004 8:04 PM by Scott Galloway

# re: An ASP.NET Framework for Human Interactive Proofs

Have to say, congratulations on the article. Great coverage of a very topicval subject!
Thursday, September 23, 2004 11:15 PM by Stephen Toub

# re: An ASP.NET Framework for Human Interactive Proofs

Thanks, Scott! Glad you like it.
Wednesday, September 29, 2004 3:57 AM by Mike O Shea

# re: An ASP.NET Framework for Human Interactive Proofs

This article seems to have covered all the current angles and is well worth the read.
Tuesday, October 12, 2004 6:52 AM by Anton Spass

# re: An ASP.NET Framework for Human Interactive Proofs

Thanks for the article, Stephen!

Would you please point the way Words collection can be set for ImageHipChallenge. I've tried to set the collection using VS designer collection editor, but it throws error message [Constructor on type System.String not found].

Thank you in advance.
Tuesday, October 12, 2004 11:45 AM by Stephen Toub

# re: An ASP.NET Framework for Human Interactive Proofs

Anton, I've post an answer to your question at http://blogs.msdn.com/toub/archive/2004/10/12/241277.aspx. Hope that helps.
Wednesday, August 03, 2005 2:54 PM by Shaun Slocumb

# re: An ASP.NET Framework for Human Interactive Proofs

I have recently tried to use your controls but am having trouble. The image only displays periodically but I get no errors. It displays correctly if I run the page locally or without the validator control in place but I haven't isolated it any further. Any suggestions. Thanks
Monday, February 27, 2006 2:30 PM by PG

# re: An ASP.NET Framework for Human Interactive Proofs

How to get this control to work (Page_Load) inside a FormView or any other data-bound control?

This works :
Me.ImageHipChallenge1.Words.Add("test")
       
This doesn't:

Dim row As FormViewRow = Me.FormView1.Row
       Dim hip As ImageHipChallenge = CType(row.FindControl("ImageHipChallenge1"), ImageHipChallenge)
       hip.Words.Add("testing")

Throws the exception:

No words available for challenge.

HipChallenge.cs
protected virtual string ChooseWord()
{
if (Words.Count == 0) throw new InvalidOperationException("No words available for challenge.");
return Words[NextRandom(Words.Count)];
}
Friday, May 12, 2006 6:48 PM by Jim Azar

# re: An ASP.NET Framework for Human Interactive Proofs

Nice work this code works great for me!  

In response to Shaun Slocumb's post above.  I had the same problem; it works fine locally, but not when deployed to W2003 server. The problem was caused by fonts specified in ImageHipChallengeHandler.cs that were did not exist on the server. I removed "Stencil" and "Century Gothic" and now it works fine.
Sunday, May 14, 2006 5:51 AM by Ben

# re: An ASP.NET Framework for Human Interactive Proofs

Hello,

Everything works fine on my development workstation (Windows XP, VS 2005) but I get the following error when deploying on my Windows 2003 x64:

________________________________________
Event code: 3005
Event message: An unhandled exception has occurred.
Event time: 5/14/2006 9:46:15 AM
Event time (UTC): 5/14/2006 9:46:15 AM
Event ID: e85d8f54977a435393eba310bcd7fcf7
Event sequence: 164
Event occurrence: 13
Event detail code: 0

Application information:
   Application domain: /LM/W3SVC/1491015058/Root/Secure-1-127920729179796735
   Trust level: Full
   Application Virtual Path: XXX
   Application Path: XXX
   Machine name: XXXX

Process information:
   Process ID: 3948
   Process name: w3wp.exe
   Account name: NT AUTHORITY\NETWORK SERVICE

Exception information:
   Exception type: TypeInitializationException
   Exception message: The type initializer for 'Msdn.Web.UI.WebControls.ImageHipChallengeHandler' threw an exception.

Request information:
   Request URL: XXX
   Request path: XXX
   User host address: XXX
   User:  
   Is authenticated: False
   Authentication Type:  
   Thread account name: NT AUTHORITY\NETWORK SERVICE

Thread information:
   Thread ID: 5
   Thread account name: NT AUTHORITY\NETWORK SERVICE
   Is impersonating: False
   Stack trace:


Custom event details:

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
________________________________________


any help would be greatly appreciated!
Sunday, May 14, 2006 9:54 AM by toub

# re: An ASP.NET Framework for Human Interactive Proofs

This is probably due to a font not being available.  If you look in the ImageHipChallengeHandler.cs file, at the end you'll see a static FontFamily member initialized to an array of fonts:

private static FontFamily [] _families = {
   new FontFamily("Times New Roman"),
   new FontFamily("Georgia"),
   new FontFamily("Stencil"),
   new FontFamily("Comic Sans MS")};

If one of those fonts isn't available on this system, the type will fail to initialize, since this array construction is done as part of the type's .cctor.  Try removing the line:
   new FontFamily("Stencil"),
and see if that fixes things.  As long as there's at least one font in this array (and as long as all of the fonts in the array are present on the machine), it should work, so feel free to change the list to whatever suits you.
Monday, September 18, 2006 4:27 PM by Dhruv

# re: An ASP.NET Framework for Human Interactive Proofs

Is there a sample available on the steps on how to use this ? Being a beginner but like the concept making it difficult to implement.
Tuesday, December 05, 2006 3:53 PM by Martin

# re: An ASP.NET Framework for Human Interactive Proofs

Hi Stephen,

I'm trying to implement you're HIP validator in a solution, however it always throws an exception in the AudioHipChallengeHandler.SpeakToFile.  The particular offending line that throws the exception is "ISpeechObjectTokens voices = speech.GetVoices(string.Empty, string.Empty)".  It throws an "Exception from HRESULT: 0x80045039", which isn't very helpful.  I tried playing around with the SpVoice class, and I would get strange "Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))" exceptions.  I'm fairly confident that it's a configuration issue, however I don't know what I have done wrong.  I'm developing in .Net 2, in VS8 on a Windows Server 2003 enviro.  NOTE: it's probably nothing, but I noticed that the  SpeechLib.dll version is 5.0, not the 5.1 and 5.3 that I've been seeing in my searches.

Tuesday, December 05, 2006 4:44 PM by Martin

# re: An ASP.NET Framework for Human Interactive Proofs

Hi Stephen,

Ok, I resolved the issues I was having in my previous post (ensure you're using the correct App pool with a user accout with sufficient privileges).  

The new issue I'm having regarding this is that it creates a .wav file that is only 1k in size with no audio in it.  If anyone has any ideas how to resolve this, it would be greatly appreciated.

Friday, December 15, 2006 5:56 AM by Jonas

# re: An ASP.NET Framework for Human Interactive Proofs

Hi Stephen,

Your HIP Challenge appears to work most of the time.. however occasionally the following code returns null into "string text" and there fore doesnt render a image. which seems to suggest the cache is not finding the ImageHipChallenge.ID_KEY

this is the part of the code....

string text = HipChallenge.GetChallengeText(new Guid(queryString[ImageHipChallenge.ID_KEY]));

           if (text != null)

           {

               // We successfully retrieved the information, so generate the image and send it to the client.

               HttpResponse resp = context.Response;

               resp.Clear();

               resp.ContentType = "img/jpeg";

               using (Bitmap bmp = GenerateImage(text, new Size(width, height)))

               {

                   bmp.Save(resp.OutputStream, ImageFormat.Jpeg);

               }

           }

any ideas on how to fix this??

thanks

Sunday, December 17, 2006 2:57 PM by toub

# re: An ASP.NET Framework for Human Interactive Proofs

If the cache is being cleared, there could be several factors.  For example, memory pressure could cause resources stored in the cache to be evicted.  Or if the ASP.NET AppDomain hosting this site restarts for some reason (due to health monitoring, a change to a dependent file, etc.), the cache would also be cleared.  I'd check for signs of any of those.

Friday, May 25, 2007 2:33 AM by Ramesh

# re: An ASP.NET Framework for Human Interactive Proofs

I am getting error ,font famally not found please any one can send the source code for it

Friday, May 25, 2007 2:37 AM by Shivakumar

# re: An ASP.NET Framework for Human Interactive Proofs

where is this file ImageHipChallenge.aspx,we need to create this file ?i am not understanding

if u got then send the file

Monday, July 02, 2007 4:55 PM by leo

# re: An ASP.NET Framework for Human Interactive Proofs

Can you guys post the aspx page here? Thanks

Wednesday, July 11, 2007 6:03 AM by pallavi

# re: An ASP.NET Framework for Human Interactive Proofs

i am not getting  ImageHipChallenge1.Words ...where to add words?

Tuesday, April 29, 2008 12:56 PM by P.Romero

# re: An ASP.NET Framework for Human Interactive Proofs

Hi there, Ive been having problems with the Words property. The get/set statements dont seem to work as you would expect. is the following correct?

[EditorBrowsable(EditorBrowsableState.Always)]

       [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]

       [Editor(

       "System.Windows.Forms.Design.StringCollectionEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a",

       "System.Drawing.Design.UITypeEditor,System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"

       )]

       public StringCollection Words

{

get

{

if (_words == null) _words = new StringCollection();

return _words;

}

           set

           {

               _words = value;

           }

}

Tuesday, April 29, 2008 1:26 PM by P.Romero

# re: An ASP.NET Framework for Human Interactive Proofs

plugging the above code into the solution produces a stringcollection editor within the designer that apparently works. However, the words colletction doesnt seem to ever get initialized, and throws the "no words available" exception at runtime.

I know that its very bad practice to try to populate the words collection through the control properties at design-time, but I want to get it to work more as an academic exercise, and Im completely stuck as to why the Words colletction isnt being populated by the stringCollection editor.

Thursday, October 23, 2008 12:00 PM by G.Magee

# re: An ASP.NET Framework for Human Interactive Proofs

I'm not receiving any errors.  However, the image is not showing for me at all.  I'm able to validate that the word that I set is validated, but the image is never displayed.  Can someone please let me know what might be causing this problem?

Thanx

Thursday, January 08, 2009 4:23 PM by Drfunkie

# re: An ASP.NET Framework for Human Interactive Proofs

Just use a huge ditionary file Huge.txt and randomly add a word to the imagehip collection.

Example:

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

           'get the LotsofWords.txt file and parse it into an array collection

           Dim intWords As Integer

           Dim objReader As New StreamReader(Server.MapPath("~/LotsofWords.txt"))

           Dim sLine As String = ""

           Dim arrText As New ArrayList

           Dim intItem As Integer = 0

           Try

               Do

                   sLine = objReader.ReadLine()

                   If Not sLine Is Nothing Then

                       arrText.Add(sLine)

                   End If

               Loop Until sLine Is Nothing

           Catch ex As Exception

           Finally

               objReader.Close()

           End Try

'Shake and Bake it baby!!

           arrText.Sort()

           arrText.Reverse()

           intWords = GetRandomNumber(0, 936)

           Dim strItem As String = Nothing

           Try

               strItem = arrText(intWords).ToString()

           Catch ext As Exception

               strItem = arrText(5).ToString()

           Finally

               'add the arrtext to the hip challanger

               ImageHipChallenge1.Words.Add(strItem)

           End Try

       End Sub

       'create the random object constructor using the datetime seconds

       Dim objRandom As New System.Random(CType(System.DateTime.Now.Ticks Mod System.Int32.MaxValue, Integer))

       Public Function GetRandomNumber(Optional ByVal Low As Integer = 1, Optional ByVal High As Integer = 100) As Integer

           ' Returns a random number,

           ' between the optional Low and High parameters

           Return objRandom.Next(Low, High + 1)

       End Function

Tuesday, June 09, 2009 7:56 PM by Stephen Toub An ASP NET Framework for Human Interactive Proofs | Joint Pain Relief

# Stephen Toub An ASP NET Framework for Human Interactive Proofs | Joint Pain Relief

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