SAP.Web.Security.TicketException: MYSAP_INVALID

Question

We recently updated our portal to the following:
J2EE Engine 6.40 PatchLevel 108290.313
Portal 6.0.20.0.0
Previously sap.web.security dll worked fine but now I get this exception
SAP.Web.Security.TicketException: MYSAP_INVALID
I have tried all the suggestions in this forum and nothing works.  Does anyone have the orginal source code for this dll or a working solution ?
the following code does get the ticket if I remove the handler from the web.config.....
            Dim cookieString As String = HttpUtility.UrlDecode((Request.Cookies("MYSAPSSO2").Value).Replace("!", "%2B"))
            Dim ticket As SAP.Web.Security.MySapSso2Ticket = New SAP.Web.Security.MySapSso2Ticket("verify.pse", cookieString)
            Dim objUsr As SAP.Web.Security.MySAPSso2Identity = New SAP.Web.Security.MySAPSso2Identity(ticket, cookieString)
so why does the handler fail ?  driving me crazy.

Answer 1

Ok so I added the code to the wiki in the attachment area. Hopefully Wiki mods don't delete it.  This works perfectly for our purposes and config.
https://www.sdn.sap.com/irj/sdn/wiki?path=/display/snippets/home&
SSOTest.rar.jpg
PortalSecurity.rar.jpg
Right Click and save the files then remove the .jpg extension.  Open with WinRAR or Winzip.
You will have to generate your own public key so take a look at the assemblyinfo.vb file.
Steps to create your own public key
C:DevelopmentPortalSecurityKeyFile>sn -k keyfile.snk
Microsoft (R) .NET Framework Strong Name Utility  Version 1.1.4322.573
Copyright (C) Microsoft Corporation 1998-2002. All rights reserved.
Key pair written to keyfile.snk
C:DevelopmentPortalSecurityKeyFile>sn -p keyfile.snk publickey.snk
Microsoft (R) .NET Framework Strong Name Utility  Version 1.1.4322.573
Copyright (C) Microsoft Corporation 1998-2002. All rights reserved.
Public key written to publickey.snk
C:DevelopmentPortalSecurityKeyFile>sn -t publickey.snk
Microsoft (R) .NET Framework Strong Name Utility  Version 1.1.4322.573
Copyright (C) Microsoft Corporation 1998-2002. All rights reserved.
Public key token is [should display your Public Key Token]
Other config...May not be necessary as you can change the code to do whatever you want.
- Note 442401 - Web server filter for SSO to third-party systems
  (https://service.sap.com/sap/support/notes/442401)
Extract the zip file attached to this SAP Note.  Follow the instructions in the SAP Note and the instructions in the "filterdocs" directory of the unzipped files. 
For our environment, I copied the iss6_sso.dll (for IIS 6) and the verify.properties files into the "inetpubscripts" directory.  (There is a "verify.properties" file attached tot the source for your reference).  Note the reference to a verify.pse file in the 'verify.properties' file.  It should point to wherever the verify.pse file is, which in our case is "c:secverify.pse".   I also copied the WPSSO_V3.DLL file from the "C in
ti386" directory to the system32 directory. 
- Note 304450 - Single-Sign-On with SAP logon tickets in non-SAP systems
  (https://service.sap.com/sap/support/notes/304450)
This SAP Note points the developer to SAPSSOEXT in SAP's software download area.  Use SAPCAR to unzip the downloaded file and follow the instructions in this SAP Note and the instructions in the DOCS directory (a PDF and a README.TXT file). 
PDF Note:  The comments portion of the MySapEvalLogonTicketEx function declaration (Section 3.2 of the PDF) indicates that an environment variable named SSF_LIB must be created/exist.  It should point to the location of the SSF-compliant security library (ie: SAPSECU.DLL in the system32 directory).