How to make SOAP calls from web application with Signed Request authentication?

Question

We have a web application, working as a Visualforce page, with Signed Request authentication. Is there a way of making SOAP API calls from backend, using the token provided in "client" field of CanvasRequest object?

This topic describes how to make SOAP calls having OAuth authentication: http://www.salesforce.com/us/developer/docs/api/Content/sforce_api_guidelines_yourtools.htm - would it work with the access token retrieved via signed request authentication? What should we put into "oauth_consumer_key", "oauth_signature" and other required fields?

Thanks!

Answer 1

Looking at the CanvasRequest the oauthToken has the distinct look of a SessionId to me.

"client":
{
"instanceId":"06Px000000002JZ",
"instanceUrl":"http://instance.salesforce.com:8080",
"oauthToken":"00Dx0000X00Or4J!ARQAQJ34YL8gKowP65p8FDHkvk.Uq5...",
"targetOrigin":"http://instance.salesforce.com:8080"
},

I reckon you could use that SessionId against the instance URL with the SOAP APIs if the user has the required permissions.