public virtual void LoadXml(XmlElement value)
{
if (value == null)
{
throw new ArgumentNullException(nameof(value));
}
ReferenceType = value.LocalName;
string uri = Utils.GetAttribute(value, "URI", EncryptedXml.XmlEncNamespaceUrl);
if (uri == null)
{
throw new ArgumentNullException(SR.Cryptography_Xml_UriRequired);
}
Uri = uri;
// Transforms
XmlNamespaceManager nsm = new XmlNamespaceManager(value.OwnerDocument.NameTable);
nsm.AddNamespace("ds", SignedXml.XmlDsigNamespaceUrl);
XmlNode transformsNode = value.SelectSingleNode("ds:Transforms", nsm);
if (transformsNode != null)
{
TransformChain.LoadXml(transformsNode as XmlElement);
}
// cache the Xml
_cachedXml = value;
}
public Reference(Stream stream)
{
_transformChain = new TransformChain();
_refTarget = stream;
_refTargetType = ReferenceTargetType.Stream;
_cachedXml = null;
_digestMethod = DefaultDigestMethod;
}
internal Reference(XmlElement element)
{
_transformChain = new TransformChain();
_refTarget = element;
_refTargetType = ReferenceTargetType.XmlElement;
_cachedXml = null;
_digestMethod = DefaultDigestMethod;
}
//
// public constructors
//
public Reference()
{
_transformChain = new TransformChain();
_refTarget = null;
_refTargetType = ReferenceTargetType.UriReference;
_cachedXml = null;
_digestMethod = DefaultDigestMethod;
}
public void AddTransform(Transform transform)
{
if (transform == null)
{
throw new ArgumentNullException(nameof(transform));
}
transform.Reference = this;
TransformChain.Add(transform);
}
internal XmlElement GetXml(XmlDocument document)
{
// Create the Reference
XmlElement referenceElement = document.CreateElement("Reference", SignedXml.XmlDsigNamespaceUrl);
if (!string.IsNullOrEmpty(_id))
{
referenceElement.SetAttribute("Id", _id);
}
if (_uri != null)
{
referenceElement.SetAttribute("URI", _uri);
}
if (!string.IsNullOrEmpty(_type))
{
referenceElement.SetAttribute("Type", _type);
}
// Add the transforms to the Reference
if (TransformChain.Count != 0)
{
referenceElement.AppendChild(TransformChain.GetXml(document, SignedXml.XmlDsigNamespaceUrl));
}
// Add the DigestMethod
if (string.IsNullOrEmpty(_digestMethod))
{
throw new CryptographicException(SR.Cryptography_Xml_DigestMethodRequired);
}
XmlElement digestMethodElement = document.CreateElement("DigestMethod", SignedXml.XmlDsigNamespaceUrl);
digestMethodElement.SetAttribute("Algorithm", _digestMethod);
referenceElement.AppendChild(digestMethodElement);
if (DigestValue == null)
{
if (_hashAlgorithm.Hash == null)
{
throw new CryptographicException(SR.Cryptography_Xml_DigestValueRequired);
}
DigestValue = _hashAlgorithm.Hash;
}
XmlElement digestValueElement = document.CreateElement("DigestValue", SignedXml.XmlDsigNamespaceUrl);
digestValueElement.AppendChild(document.CreateTextNode(Convert.ToBase64String(_digestValue)));
referenceElement.AppendChild(digestValueElement);
return(referenceElement);
}
private bool ReferenceUsesSafeTransformMethods(Reference reference)
{
TransformChain transformChain = reference.TransformChain;
int transformCount = transformChain.Count;
for (int i = 0; i < transformCount; i++)
{
Transform transform = transformChain[i];
if (!IsSafeTransform(transform.Algorithm))
{
return(false);
}
}
return(true);
}
internal XmlElement GetXml(XmlDocument document)
{
if (ReferenceType == null)
{
throw new CryptographicException(SR.Cryptography_Xml_ReferenceTypeRequired);
}
// Create the Reference
XmlElement referenceElement = document.CreateElement(ReferenceType, EncryptedXml.XmlEncNamespaceUrl);
if (!string.IsNullOrEmpty(_uri))
{
referenceElement.SetAttribute("URI", _uri);
}
// Add the transforms to the CipherReference
if (TransformChain.Count > 0)
{
referenceElement.AppendChild(TransformChain.GetXml(document, SignedXml.XmlDsigNamespaceUrl));
}
return(referenceElement);
}
public DataReference(string uri, TransformChain transformChain) : base(uri, transformChain)
{
ReferenceType = "DataReference";
}
//
// private methods
//
private byte[] GetCipherValue(CipherData cipherData)
{
if (cipherData == null)
{
throw new ArgumentNullException(nameof(cipherData));
}
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;
if (cipherData.CipherReference.Uri == null)
{
throw new CryptographicException(SR.Cryptography_Xml_UriNotSupported);
}
// See if the CipherReference is a local URI
if (cipherData.CipherReference.Uri.Length == 0)
{
// self referenced Uri
string baseUri = (_document == null ? null : _document.BaseURI);
TransformChain tc = cipherData.CipherReference.TransformChain;
if (tc == null)
{
throw new CryptographicException(SR.Cryptography_Xml_UriNotSupported);
}
decInputStream = tc.TransformToOctetStream(_document, _xmlResolver, baseUri);
}
else if (cipherData.CipherReference.Uri[0] == '#')
{
string idref = Utils.ExtractIdFromLocalUri(cipherData.CipherReference.Uri);
// Serialize
XmlElement idElem = GetIdElement(_document, idref);
if (idElem == null || idElem.OuterXml == null)
{
throw new CryptographicException(SR.Cryptography_Xml_UriNotSupported);
}
inputStream = new MemoryStream(_encoding.GetBytes(idElem.OuterXml));
string baseUri = (_document == null ? null : _document.BaseURI);
TransformChain tc = cipherData.CipherReference.TransformChain;
if (tc == null)
{
throw new CryptographicException(SR.Cryptography_Xml_UriNotSupported);
}
decInputStream = tc.TransformToOctetStream(inputStream, _xmlResolver, baseUri);
}
else
{
throw new CryptographicException(SR.Cryptography_Xml_UriNotResolved, cipherData.CipherReference.Uri);
}
// 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 (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(SR.Cryptography_Xml_MissingCipherData);
}
protected EncryptedReference(string uri, TransformChain transformChain)
{
TransformChain = transformChain;
Uri = uri;
_cachedXml = null;
}
// 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
_hashAlgorithm = CryptoHelpers.CreateFromName <HashAlgorithm>(_digestMethod);
if (_hashAlgorithm == null)
{
throw new CryptographicException(SR.Cryptography_Xml_CreateHashAlgorithmFailed);
}
// 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 = (SignedXml.ResolverSet ? SignedXml._xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), baseUri));
byte[] 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
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)
{
// 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 || _uri == "#xpointer(/)")
{
// 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 CryptographicException(SR.Format(SR.Cryptography_Xml_SelfReferenceRequiresContext, _uri));
}
// Normalize the containing document
XmlDocument doc = Utils.PreProcessDocumentInput(document, resolver, baseUri);
// Remove comments only if URI is ""
if (_uri.Length == 0)
{
Utils.DiscardComments(doc);
}
hashInputStream = TransformChain.TransformToOctetStream(doc, 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);
XmlElement elem = SignedXml.GetIdElement(document, idref);
if (elem == null)
{
// Go throw the referenced items passed in
if (refList != null)
{
foreach (XmlNode node in refList)
{
XmlElement tempElem = node.SelectSingleNode("//*[@Id='" + idref + "']") as XmlElement;
//XmlElement tempElem = node as XmlElement;
//if ((tempElem != null) && (Utils.HasAttribute(tempElem, "Id", SignedXml.XmlDsigNamespaceUrl))
// && (Utils.GetAttribute(tempElem, "Id", SignedXml.XmlDsigNamespaceUrl).Equals(idref)))
if (tempElem != null)
{
// copy fragment to document with root, create nodelsit
elem = tempElem;
XmlDocument doc = Utils.PreProcessElementInput(elem, resolver, baseUri);
if (_signedXml._context != null)
{
CanonicalXmlNodeList namespaces = Utils.GetPropagatedAttributes(_signedXml._context);
Utils.AddNamespaces(doc.DocumentElement, namespaces);
}
elem = doc.DocumentElement.FirstChild as XmlElement;
break;
}
}
}
if (elem == null)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidReference);
}
}
else
{
// create node list from document
XmlDocument doc = Utils.PreProcessElementInput(elem, resolver, baseUri);
CanonicalXmlNodeList namespaces = Utils.GetPropagatedAttributes(elem);
Utils.AddNamespaces(doc.DocumentElement, namespaces);
elem = doc.DocumentElement.FirstChild as XmlElement;
}
hashInputStream = TransformChain.TransformToOctetStream(Utils.AllDescendantNodes(elem, !discardComments), typeof(XmlNodeList), resolver, baseUri);
}
else
{
throw new CryptographicException(SR.Cryptography_Xml_UriNotResolved, _uri);
}
break;
case ReferenceTargetType.XmlElement:
// We need to create a DocumentNavigator out of the XmlElement
hashInputStream = TransformChain.TransformToOctetStream(Utils.AllDescendantNodes((XmlNode)_refTarget, true), typeof(XmlNodeList), resolver, baseUri);
break;
default:
throw new CryptographicException(SR.Cryptography_Xml_UriNotResolved, _uri);
}
// Compute the new hash value
hashInputStream = SignedXmlDebugLog.LogReferenceData(this, hashInputStream);
hashval = _hashAlgorithm.ComputeHash(hashInputStream);
}
finally
{
if (hashInputStream != null)
{
hashInputStream.Close();
}
if (response != null)
{
response.Close();
}
if (inputStream != null)
{
inputStream.Close();
}
}
return(hashval);
}
public void LoadXml(XmlElement value)
{
if (value == null)
{
throw new ArgumentNullException(nameof(value));
}
_id = Utils.GetAttribute(value, "Id", SignedXml.XmlDsigNamespaceUrl);
_uri = Utils.GetAttribute(value, "URI", SignedXml.XmlDsigNamespaceUrl);
_type = Utils.GetAttribute(value, "Type", SignedXml.XmlDsigNamespaceUrl);
if (!Utils.VerifyAttributes(value, new string[] { "Id", "URI", "Type" }))
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference");
}
XmlNamespaceManager nsm = new XmlNamespaceManager(value.OwnerDocument.NameTable);
nsm.AddNamespace("ds", SignedXml.XmlDsigNamespaceUrl);
// Transforms
bool hasTransforms = false;
TransformChain = new TransformChain();
XmlNodeList transformsNodes = value.SelectNodes("ds:Transforms", nsm);
if (transformsNodes != null && transformsNodes.Count != 0)
{
if (transformsNodes.Count > 1)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference/Transforms");
}
hasTransforms = true;
XmlElement transformsElement = transformsNodes[0] as XmlElement;
if (!Utils.VerifyAttributes(transformsElement, (string[])null))
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference/Transforms");
}
XmlNodeList transformNodes = transformsElement.SelectNodes("ds:Transform", nsm);
if (transformNodes != null)
{
if (transformNodes.Count != transformsElement.SelectNodes("*").Count)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference/Transforms");
}
if (transformNodes.Count > Utils.MaxTransformsPerReference)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference/Transforms");
}
foreach (XmlNode transformNode in transformNodes)
{
XmlElement transformElement = transformNode as XmlElement;
string algorithm = Utils.GetAttribute(transformElement, "Algorithm", SignedXml.XmlDsigNamespaceUrl);
if (algorithm == null || !Utils.VerifyAttributes(transformElement, "Algorithm"))
{
throw new CryptographicException(SR.Cryptography_Xml_UnknownTransform);
}
Transform transform = CryptoHelpers.CreateFromName <Transform>(algorithm);
if (transform == null)
{
throw new CryptographicException(SR.Cryptography_Xml_UnknownTransform);
}
AddTransform(transform);
// let the transform read the children of the transformElement for data
transform.LoadInnerXml(transformElement.ChildNodes);
// Hack! this is done to get around the lack of here() function support in XPath
if (transform is XmlDsigEnvelopedSignatureTransform)
{
// Walk back to the Signature tag. Find the nearest signature ancestor
// Signature-->SignedInfo-->Reference-->Transforms-->Transform
XmlNode signatureTag = transformElement.SelectSingleNode("ancestor::ds:Signature[1]", nsm);
XmlNodeList signatureList = transformElement.SelectNodes("//ds:Signature", nsm);
if (signatureList != null)
{
int position = 0;
foreach (XmlNode node in signatureList)
{
position++;
if (node == signatureTag)
{
((XmlDsigEnvelopedSignatureTransform)transform).SignaturePosition = position;
break;
}
}
}
}
}
}
}
// DigestMethod
XmlNodeList digestMethodNodes = value.SelectNodes("ds:DigestMethod", nsm);
if (digestMethodNodes == null || digestMethodNodes.Count == 0 || digestMethodNodes.Count > 1)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference/DigestMethod");
}
XmlElement digestMethodElement = digestMethodNodes[0] as XmlElement;
_digestMethod = Utils.GetAttribute(digestMethodElement, "Algorithm", SignedXml.XmlDsigNamespaceUrl);
if (_digestMethod == null || !Utils.VerifyAttributes(digestMethodElement, "Algorithm"))
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference/DigestMethod");
}
// DigestValue
XmlNodeList digestValueNodes = value.SelectNodes("ds:DigestValue", nsm);
if (digestValueNodes == null || digestValueNodes.Count == 0 || digestValueNodes.Count > 1)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference/DigestValue");
}
XmlElement digestValueElement = digestValueNodes[0] as XmlElement;
_digestValue = Convert.FromBase64String(Utils.DiscardWhiteSpaces(digestValueElement.InnerText));
if (!Utils.VerifyAttributes(digestValueElement, (string[])null))
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference/DigestValue");
}
// Verify that there aren't any extra nodes that aren't allowed
int expectedChildNodeCount = hasTransforms ? 3 : 2;
if (value.SelectNodes("*").Count != expectedChildNodeCount)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidElement, "Reference");
}
// cache the Xml
_cachedXml = value;
}
public CipherReference(string uri, TransformChain transformChain) : base(uri, transformChain)
{
ReferenceType = "CipherReference";
}
