How to pass user credentials between apps on the same server?

I have a wordpress site that authenticates against a local ldap database for users to login. On the same server and domain I have subsonic installed that also authenticates against the same ldap database. The ldap database is firewalled front the outside wall and the internal LAN.

I would like to create a link from a wordpress page to the subsonic login page and also pass the user credentials at the same time to allow a seamless logon for the user into the subsonic app but do this in a secure fashion.

The url format for the wordpress site is home.mydomain.com/wordpress and for the subsonic app it's home.mydomain.com:4141
Both sites can be put on https if that helps?

Please be gentle as I have no coding experience. Thanks

any suggestions?

Will the SharePoint application and ASP.NET application hosted on the same server? If on the same server, credentials will be carried over, so, all you need to do is enable windows integrated authentication in your SharePoint application (Assuming it is what user will be accessing first)
If they both are going to be hosted on separate servers then kerberos delegation need to be configured on servers

Thanks for the reply, but it's a linux (ubuntu) server not windows.

I think you may have replied to the wrong thread?