procedure SetDownloadCredentials(const User, Pass: String);
Sets the basic authentication username and password for all following downloads done by DownloadTemporaryFile, DownloadTemporaryFileWithISSigVerify, DownloadTemporaryFileSize, and DownloadTemporaryFileDate.
Specify an empty username or password to unset the username or password.
DownloadTemporaryFile
DownloadTemporaryFileWithISSigVerify
DownloadTemporaryFileSize
DownloadTemporaryFileDate