Hi,

OAuth  (Open Authorization)  is an open protocol to allow secure API authorization in a simple and standardized way from desktop, web applications. The Force.com platform implements the  OAuth  2.0 standard, so users can authorize applications to access Force.com resources (via the Force.com REST and SOAP Web Service APIs) on their behalf without revealing their passwords or other credentials to those applications. Alternatively, applications can directly authenticate to access the same resources outside the context of an end user.

To begin with OAuth authentication, you will first have to create an App in your twitter account.

After Creating the App you will get the following values.

a. OAuth Service Name

b. Access Token URL

c. Authorization URL

d. Consumer Key     

e. Consumer Secret

f. Request Token URL

After this you can do the Oauth Authentication to get the Access token.

Now in order to Authenticate you can make use of the OAuth , AuthController  classes .

OAuth class = http://code.google.com/p/sfdc-oauth-playground/source/browse/trunk/OAuth/src/classes/OAuth.cls?r=10

AuthController  classes = http://code.google.com/p/sfdc-oauth-playground/source/browse/trunk/OAuth/src/classes/AuthController.cls?r=10

Once Complete Authentication is done, then you store those permanent credentials (i.e., Access token) because they are used (along with your Consumer key and Consumer secret) to sign (i.e., authenticate) HTTP requests to Twitter’s APIs.

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