Using username and password in HTTP or SOAP Header for STS based authentication

Question

Hi,

I have Windows Identity Foundation based WCF service. I have issues with interoperability because it seems to be kind of hard to implement PHP or Perl client for such service due to all WS-* protocols.

Currently it works like this:

1. Client authenticates at STS (using username and password) and receives SAML token containing required claims

2. Client accesses WCF service and provides SAML token with claims received by STS using WS-Federation

3. In the WCF service client is now authenticated.

I would like to make an alternative binding (but keep the existing federated binding) that would work like this:

1. Client contacts WCF service, sending username and password in HTTP or SOAP headers

2. WCF Service contacts STS using username and password (from headers) and retreives required claims

(no ws-federation, or any other ws-* protocol)

Anyone has a clue on what would be the best way of doing this?