A proxy server is used as a security barrier between the internal network and the Internet. This protects the internal network from unauthorized access. A proxy server also enhances speed performance since it caches recently used documents. To gain access to a proxy server, the Windows CE–based application needs a proxy authentication scheme.
When a Windows CE–based application tries to use a proxy server that requires authentication, the proxy returns a 407 status code message to the client. In that message, the proxy should include one or more Proxy-Authenticate response headers. These headers include the authentication methods available from the proxy. The Windows CE Internet functions pick the first method they recognize.
To get user name and password from the user the application can use the InternetErrorDlg function.
A custom interface can use InternetSetOption to set the INTERNET_OPTION_PROXY_PASSWORD and INTERNET_OPTION_PROXY_USERNAME values and then resend the request to the proxy.
If no proxy user name and password are set, the Windows CE Internet functions attempt to use the user name and password for the server.