Setting Data Source Credentials in a URL
You can provide data source credentials in a URL by including the prefix:datasourcename=value parameter string, where prefix is either dsu (for user name) or dsp (for password) and datasourcename is the name of the data source for which to supply credentials.
A user name and password are used when a report server must connect to an external data source to retrieve report data. You can specify multiple data sources as part of the URL string.
You should pass values for these parameters only when the credential setting for a connection is set to Prompt. If these parameters are not specified and the credential setting is set to Prompt, the report is not executed. If the credential setting is not set to Prompt, the values are ignored. For more about data source properties and settings, see Managing Report Data Sources.
User names and passwords are transmitted as clear text unless the user or application uses Secure Sockets Layer (SSL). You cannot transmit credentials using a URL if the SecureConnectionLevel setting is set to a value of 1 or greater. For more information, see Using Secure Web Service Methods.
It is highly recommended that you use secure protocols when passing credentials to the server via a URL. When possible, use SSL encryption. Avoid transmitting passwords in clear text.