install root certificate

RootCertificates.cs

    public static class RootCertificates
    {
        public static async void AddEsteidSk()
        {
            try
            {
                var certificateFile = new Uri("ms-appx:///Assets/ESTEID-SK_2015.der.crt");
                var file = await StorageFile.GetFileFromApplicationUriAsync(certificateFile);
                var certBlob = await FileIO.ReadBufferAsync(file);
                var trustedStore = CertificateStores.TrustedRootCertificationAuthorities;
                var rootCert = new Certificate(certBlob);

                trustedStore.Add(rootCert);
            }
            catch (Exception ex)
            {
                throw new DigiDocException("Could not add EsteidSK root cert", ex);
            }
        }
    }