//
// private methods
//
private byte[] GetCipherValue(CipherData cipherData)
{
if (cipherData == null)
{
throw new ArgumentNullException("cipherData");
}
WebResponse response = null;
Stream inputStream = null;
if (cipherData.CipherValue != null)
{
return(cipherData.CipherValue);
}
else if (cipherData.CipherReference != null)
{
if (cipherData.CipherReference.CipherValue != null)
{
return(cipherData.CipherReference.CipherValue);
}
Stream decInputStream = null;
// See if the CipherReference is a local URI
if (cipherData.CipherReference.Uri.Length == 0)
{
// self referenced Uri
string baseUri = (m_document == null ? null : m_document.BaseURI);
TransformChain tc = cipherData.CipherReference.TransformChain;
decInputStream = tc.TransformToOctetStream(m_document, m_xmlResolver, baseUri);
}
else if (cipherData.CipherReference.Uri[0] == '#')
{
string idref = Utils.ExtractIdFromLocalUri(cipherData.CipherReference.Uri);
// Serialize
inputStream = new MemoryStream(m_encoding.GetBytes(GetIdElement(m_document, idref).OuterXml));
string baseUri = (m_document == null ? null : m_document.BaseURI);
TransformChain tc = cipherData.CipherReference.TransformChain;
decInputStream = tc.TransformToOctetStream(inputStream, m_xmlResolver, baseUri);
}
else
{
DownloadCipherValue(cipherData, out inputStream, out decInputStream, out response);
}
// read the output stream into a memory stream
byte[] cipherValue = null;
using (MemoryStream ms = new MemoryStream()) {
Utils.Pump(decInputStream, ms);
cipherValue = ms.ToArray();
// Close the stream and return
if (response != null)
{
response.Close();
}
if (inputStream != null)
{
inputStream.Close();
}
decInputStream.Close();
}
// cache the cipher value for Perf reasons in case we call this routine twice
cipherData.CipherReference.CipherValue = cipherValue;
return(cipherValue);
}
// Throw a CryptographicException if we were unable to retrieve the cipher data.
throw new CryptographicException(SecurityResources.GetResourceString("Cryptography_Xml_MissingCipherData"));
}
