c# - Create MVC 3 ASPXAUTH cookie from MVC 5.1 application - Single Sign on -

i have 2 seperate websites, main 1 running .net 4.5 mvc 5.1 other on subdomain running .net 4.0 mvc3.

i want single sign-in when user logs main site need set cookie subdomain read if user logged in there too. problem calling formsauthentication.setauthcookie same paramters 2 application results in different cookie. need create mvc 3 aspxauth cookie from mvc 5.1 application

simply using mvc 5.1 generated cookie doesn't log user mvc 3 application. i've set machine key same both application 1 generated mvc3 50 characters longer 1 set (total 150+ characters).

actually here's 2 cookies:

using system.web.security.cryptography; byte[] binarymvc3cookie = cryptoutil.hextobinary("0b406403c8fb8de06fbf43291c48bed31c41fc2dcdfb81541a65a2b842e63b609fa6d146f3cf68968240ed5d5ef75a2fec2c0d4b4ff99cd4daf974d264a08d794bbf75eb6c4f40f08f9a6a97b1a4e130b9fc9cc9e5c55e93d06d9a9d56427110637874da4059d18d0d4929de04360df72e13db09"); byte[] binarymvc5cookie = cryptoutil.hextobinary("6d0c1b88cc6fb663b59fbaec4bbdf02751c8ec70f2988bbc175f750af7ce32412bfb2c8f79d24b0e6e832a51ccf479d7492a49d808a8c101fab050e410d8f561bd7944694df7dd74f09cf348d1bdd7e2bc0d9709"); 

formsauthentication.decrypt() works fine on mvc5 cookie (of course since generated there) throws cryptography exception mvc 3 cookie. decompiled assembly , executed lines of interest in immediate window find exception throw internally following line:

icryptoservice cryptoservice = aspnetcryptoserviceprovider.instance.getcryptoservice(purpose.formsauthentication_ticket, cryptoserviceoptions.none); byte[] numarray = cryptoservice.unprotect(binarymvc3cookie); //here exception  

i'm going need recreate mvc 3 cookie mvc 5.1 app. if has ideas please tell!

edit: had epiphany how circumvent hackery. i'll make webclient call mvc 3 app , correct cookie value. =o (note making webclient call login method on mvc3 application , having call formsauthentication.setauthcookie did not work. had send cookie value on , set subdomain cookie in main app

we improved entire cryptographic stack in asp.net 4.5. end result forms authentication ticket format different mvc 3 (.net 4.0) application vs. mvc 5.1 (.net 4.5) application.

see http://blogs.msdn.com/b/webdev/archive/2012/10/23/cryptographic-improvements-in-asp-net-4-5-pt-2.aspx lots more info on this. here's excerpt document detailing how achieve backward compatibility can share cookies between .net 4.0 , .net 4.5 applications:

if writing application targeting asp.net 4.5 (you have set <httpruntime targetframework="4.5" />) , need share tickets applications running earlier versions of asp.net, must set following in 4.5 project's web.config:

<machinekey compatibilitymode="framework20sp1" />