private void GetC14NDigest(IHash hash)
{
bool isKeyedHashAlgorithm = hash is MacHashWrapper;
if (isKeyedHashAlgorithm || !_bCacheValid || !SignedInfo.CacheValid)
{
string baseUri = (_containingDocument == null ? null : _containingDocument.BaseURI);
XmlResolver resolver = (_bResolverSet ? _xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), baseUri));
XmlDocument doc = Utils.PreProcessElementInput(SignedInfo.GetXml(), resolver, baseUri);
// Add non default namespaces in scope
CanonicalXmlNodeList namespaces = (_context == null ? null : Utils.GetPropagatedAttributes(_context));
SignedXmlDebugLog.LogNamespacePropagation(this, namespaces);
Utils.AddNamespaces(doc.DocumentElement, namespaces);
Transform c14nMethodTransform = SignedInfo.CanonicalizationMethodObject;
c14nMethodTransform.Resolver = resolver;
c14nMethodTransform.BaseURI = baseUri;
SignedXmlDebugLog.LogBeginCanonicalization(this, c14nMethodTransform);
c14nMethodTransform.LoadInput(doc);
SignedXmlDebugLog.LogCanonicalizedOutput(this, c14nMethodTransform);
c14nMethodTransform.GetDigestedOutput(hash);
_bCacheValid = !isKeyedHashAlgorithm;
}
}
public override object GetOutput()
{
// decrypt the encrypted sections
if (_encryptedDataList != null)
{
ProcessElementRecursively(_encryptedDataList);
}
// propagate namespaces
Utils.AddNamespaces(_containingDocument.DocumentElement, PropagatedNamespaces);
return(_containingDocument);
}
// What we want to do is pump the input throug the TransformChain and then
// hash the output of the chain document is the document context for resolving relative references
internal byte[] CalculateHashValue(XmlDocument document, CanonicalXmlNodeList refList)
{
// refList is a list of elements that might be targets of references
// Now's the time to create our hashing algorithm
IDigest digest = CryptoHelpers.CreateFromName <IDigest>(_digestMethod);
if (digest == null)
{
IMac mac = CryptoHelpers.CreateFromName <IMac>(_digestMethod);
if (mac == null)
{
throw new System.Security.Cryptography.CryptographicException(SR.Cryptography_Xml_CreateHashAlgorithmFailed);
}
// For compatibility to corefx' HMAC implementation
byte[] randomKey = Utils.GenerateRandomBlock(mac.GetMacSize());
mac.Init(new KeyParameter(randomKey));
_hashAlgorithm = new MacHashWrapper(mac);
}
else
{
_hashAlgorithm = new DigestHashWrapper(digest);
}
// Let's go get the target.
string baseUri = (document == null ? System.Environment.CurrentDirectory + "\\" : document.BaseURI);
Stream hashInputStream = null;
WebResponse response = null;
Stream inputStream = null;
XmlResolver resolver = null;
_hashval = null;
try
{
switch (_refTargetType)
{
case ReferenceTargetType.Stream:
// This is the easiest case. We already have a stream, so just pump it through the TransformChain
resolver = (SignedXml.ResolverSet ? SignedXml._xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), baseUri));
hashInputStream = TransformChain.TransformToOctetStream((Stream)_refTarget, resolver, baseUri);
break;
case ReferenceTargetType.UriReference:
// Second-easiest case -- dereference the URI & pump through the TransformChain
// handle the special cases where the URI is null (meaning whole doc)
// or the URI is just a fragment (meaning a reference to an embedded Object)
if (_uri == null)
{
// We need to create a DocumentNavigator out of the XmlElement
resolver = (SignedXml.ResolverSet ? SignedXml._xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), baseUri));
// In the case of a Uri-less reference, we will simply pass null to the transform chain.
// The first transform in the chain is expected to know how to retrieve the data to hash.
hashInputStream = TransformChain.TransformToOctetStream((Stream)null, resolver, baseUri);
}
else if (_uri.Length == 0)
{
// This is the self-referential case. First, check that we have a document context.
// The Enveloped Signature does not discard comments as per spec; those will be omitted during the transform chain process
if (document == null)
{
throw new System.Security.Cryptography.CryptographicException(string.Format(CultureInfo.CurrentCulture, SR.Cryptography_Xml_SelfReferenceRequiresContext, _uri));
}
// Normalize the containing document
resolver = (SignedXml.ResolverSet ? SignedXml._xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), baseUri));
XmlDocument docWithNoComments = Utils.DiscardComments(Utils.PreProcessDocumentInput(document, resolver, baseUri));
hashInputStream = TransformChain.TransformToOctetStream(docWithNoComments, resolver, baseUri);
}
else if (_uri[0] == '#')
{
// If we get here, then we are constructing a Reference to an embedded DataObject
// referenced by an Id = attribute. Go find the relevant object
bool discardComments = true;
string idref = Utils.GetIdFromLocalUri(_uri, out discardComments);
if (idref == "xpointer(/)")
{
// This is a self referencial case
if (document == null)
{
throw new System.Security.Cryptography.CryptographicException(string.Format(CultureInfo.CurrentCulture, SR.Cryptography_Xml_SelfReferenceRequiresContext, _uri));
}
// We should not discard comments here!!!
resolver = (SignedXml.ResolverSet ? SignedXml._xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), baseUri));
hashInputStream = TransformChain.TransformToOctetStream(Utils.PreProcessDocumentInput(document, resolver, baseUri), resolver, baseUri);
break;
}
XmlElement elem = SignedXml.GetIdElement(document, idref);
if (elem != null)
{
_namespaces = Utils.GetPropagatedAttributes(elem.ParentNode as XmlElement);
}
if (elem == null)
{
// Go throw the referenced items passed in
if (refList != null)
{
foreach (XmlNode node in refList)
{
XmlElement tempElem = node as XmlElement;
if ((tempElem != null) && (Utils.HasAttribute(tempElem, "Id", SignedXml.XmlDsigNamespaceUrl)) &&
(Utils.GetAttribute(tempElem, "Id", SignedXml.XmlDsigNamespaceUrl).Equals(idref)))
{
elem = tempElem;
if (_signedXml._context != null)
{
_namespaces = Utils.GetPropagatedAttributes(_signedXml._context);
}
break;
}
}
}
}
if (elem == null)
{
throw new System.Security.Cryptography.CryptographicException(SR.Cryptography_Xml_InvalidReference);
}
XmlDocument normDocument = Utils.PreProcessElementInput(elem, resolver, baseUri);
// Add the propagated attributes
Utils.AddNamespaces(normDocument.DocumentElement, _namespaces);
resolver = (SignedXml.ResolverSet ? SignedXml._xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), baseUri));
if (discardComments)
{
// We should discard comments before going into the transform chain
XmlDocument docWithNoComments = Utils.DiscardComments(normDocument);
hashInputStream = TransformChain.TransformToOctetStream(docWithNoComments, resolver, baseUri);
}
else
{
// This is an XPointer reference, do not discard comments!!!
hashInputStream = TransformChain.TransformToOctetStream(normDocument, resolver, baseUri);
}
}
else
{
throw new System.Security.Cryptography.CryptographicException(SR.Cryptography_Xml_UriNotResolved, _uri);
}
break;
case ReferenceTargetType.XmlElement:
// We need to create a DocumentNavigator out of the XmlElement
resolver = (SignedXml.ResolverSet ? SignedXml._xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), baseUri));
hashInputStream = TransformChain.TransformToOctetStream(Utils.PreProcessElementInput((XmlElement)_refTarget, resolver, baseUri), resolver, baseUri);
break;
default:
throw new System.Security.Cryptography.CryptographicException(SR.Cryptography_Xml_UriNotResolved, _uri);
}
// Compute the new hash value
hashInputStream = SignedXmlDebugLog.LogReferenceData(this, hashInputStream);
// Default the buffer size to 4K.
byte[] buffer = new byte[4096];
int bytesRead;
_hashAlgorithm.Reset();
while ((bytesRead = hashInputStream.Read(buffer, 0, buffer.Length)) > 0)
{
_hashAlgorithm.BlockUpdate(buffer, 0, bytesRead);
}
_hashval = new byte[_hashAlgorithm.GetHashSize()];
_hashAlgorithm.DoFinal(_hashval, 0);
}
finally
{
if (hashInputStream != null)
{
hashInputStream.Close();
}
if (response != null)
{
response.Close();
}
if (inputStream != null)
{
inputStream.Close();
}
}
return(_hashval);
}