== Authentication

The '''ECOMS-UDG''' is based on a password-protected THREDDS using OPeNDAP and other remote data access protocols. Therefore, before accessing the data, authentication is required. To this aim, user's must be registered and activate the required roles, as described in the [http://meteo.unican.es/trac/wiki/udg/ecoms/dataserver/registration Registration section].

Once registered as users, the registration within the R session can be easily accomplished assuming that we already have a valid username, role and password, with a simple call to the function `loginUDG`, providing HTTP authentication:

{{{#!comment  To this aim, in the following lines we illustrate how to proceed using the R-to-Java interface provided by the package `rJava` (For more information on the authentication procedure click on [http://www.unidata.ucar.edu/software/netcdf-java/v4.3/javadocAll/ucar/nc2/util/net/HTTPBasicProvider.html the help page]).
}}}

{{{
#!text/R 
username <- "myUsername" # This is a character string with the username
password <- "myPassword" # This is a character string with the password
loginUDG(myUsername, myPassword)
}}}

In case the connection is performed via a proxy server, it is necessary to set it up prior to the authentication step.

{{{
#!text/R 
proxyHost <- "proxy.host.com" # Your institution Proxy configuration: host
proxyPort <- as.integer(1234) # and port
loginUDG(myUsername,
         myPassword,
         proxy.host = proxyHost,
         proxy.port = proxyPort)

}}}

Note that the object `proxyHost` is a character string while the `proxyPort` must be an integer value.