SignedInfo.cs :  » 2.6.4-mono-.net-core » System.Security » System » Security » Cryptography » Xml » C# / CSharp Open Source

//
// SignedInfo.cs - SignedInfo implementation for XML Signature
//
// Author:
//  Sebastien Pouliot  <sebastien@ximian.com>
//      Tim Coleman (tim@timcoleman.com)
//
// (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
// Copyright (C) Tim Coleman, 2004
// Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System.Collections;
using System.Runtime.InteropServices;
using System.Xml;

namespace System.Security.Cryptography.Xml{ 

  public class SignedInfo : ICollection, IEnumerable {

    private ArrayList references;
    private string c14nMethod;
    private string id;
    private string signatureMethod;
    private string signatureLength;
    private XmlElement element;

    public SignedInfo() 
    {
      references = new ArrayList ();
      c14nMethod = "http://www.w3.org/TR/2001/REC-xml-c14n-20010315";
    }

    public string CanonicalizationMethod {
      get { return c14nMethod; }
      set {
        c14nMethod = value;
        element = null;
      }
    }

#if NET_2_0
    [ComVisible (false)]
    [MonoTODO]
    public Transform CanonicalizationMethodObject {
      get { throw new NotImplementedException (); }
    }
#endif

    // documented as not supported (and throwing exception)
    public int Count {
      get { throw new NotSupportedException (); }
    }

    public string Id {
      get { return id; }
      set {
        element = null;
        id = value;
      }
    }

    // documented as not supported (and throwing exception)
    public bool IsReadOnly {
      get { throw new NotSupportedException (); }
    }

    // documented as not supported (and throwing exception)
    public bool IsSynchronized {
      get { throw new NotSupportedException (); }
    }

    // Manipulating this array never affects GetXml() when 
    // LoadXml() was used. 
    // (Actually, there is no way to detect modification.)
    public ArrayList References {
      get { return references; }
    }

    public string SignatureLength {
      get { return signatureLength; }
      set {
        element = null;
        signatureLength = value;
      }
    }

    public string SignatureMethod {
      get { return signatureMethod; }
      set {
        element = null;
        signatureMethod = value;
      }
    }

    // documented as not supported (and throwing exception)
    public object SyncRoot {
      get { throw new NotSupportedException (); }
    }

    public void AddReference (Reference reference) 
    {
      references.Add (reference);
    }

    // documented as not supported (and throwing exception)
    public void CopyTo (Array array, int index) 
    {
      throw new NotSupportedException ();
    }

    public IEnumerator GetEnumerator () 
    {
      return references.GetEnumerator ();
    }

    public XmlElement GetXml ()
    {
      if (element != null)
        return element;

      if (signatureMethod == null)
        throw new CryptographicException ("SignatureMethod");
      if (references.Count == 0)
        throw new CryptographicException ("References empty");

      XmlDocument document = new XmlDocument ();
      XmlElement xel = document.CreateElement (XmlSignature.ElementNames.SignedInfo, XmlSignature.NamespaceURI);
      if (id != null)
        xel.SetAttribute (XmlSignature.AttributeNames.Id, id);

      if (c14nMethod != null) {
        XmlElement c14n = document.CreateElement (XmlSignature.ElementNames.CanonicalizationMethod, XmlSignature.NamespaceURI);
        c14n.SetAttribute (XmlSignature.AttributeNames.Algorithm, c14nMethod);
        xel.AppendChild (c14n);
      }
      if (signatureMethod != null) {
        XmlElement sm = document.CreateElement (XmlSignature.ElementNames.SignatureMethod, XmlSignature.NamespaceURI);
        sm.SetAttribute (XmlSignature.AttributeNames.Algorithm, signatureMethod);
        if (signatureLength != null) {
          XmlElement hmac = document.CreateElement (XmlSignature.ElementNames.HMACOutputLength, XmlSignature.NamespaceURI);
          hmac.InnerText = signatureLength;
          sm.AppendChild (hmac);
        }
        xel.AppendChild (sm);
      }

      // This check is only done when element is created here.
      if (references.Count == 0)
        throw new CryptographicException ("At least one Reference element is required in SignedInfo.");

      // we add References afterward so we don't end up with extraneous
      // xmlns="..." in each reference elements.
      foreach (Reference r in references) {
        XmlNode xn = r.GetXml ();
        XmlNode newNode = document.ImportNode (xn, true);
        xel.AppendChild (newNode);
      }

      return xel;
    }

    private string GetAttribute (XmlElement xel, string attribute) 
    {
      XmlAttribute xa = xel.Attributes [attribute];
      return ((xa != null) ? xa.InnerText : null);
    }

    public void LoadXml (XmlElement value) 
    {
      if (value == null)
        throw new ArgumentNullException ("value");

      if ((value.LocalName != XmlSignature.ElementNames.SignedInfo) || (value.NamespaceURI != XmlSignature.NamespaceURI))
        throw new CryptographicException ();

      id = GetAttribute (value, XmlSignature.AttributeNames.Id);
      c14nMethod = XmlSignature.GetAttributeFromElement (value, XmlSignature.AttributeNames.Algorithm, XmlSignature.ElementNames.CanonicalizationMethod);

      XmlElement sm = XmlSignature.GetChildElement (value, XmlSignature.ElementNames.SignatureMethod, XmlSignature.NamespaceURI);
      if (sm != null) {
        signatureMethod = sm.GetAttribute (XmlSignature.AttributeNames.Algorithm);
        XmlElement length = XmlSignature.GetChildElement (sm, XmlSignature.ElementNames.HMACOutputLength, XmlSignature.NamespaceURI);
        if (length != null) {
          signatureLength = length.InnerText;
        }
      }

      for (int i = 0; i < value.ChildNodes.Count; i++) {
        XmlNode n = value.ChildNodes [i];
        if (n.NodeType == XmlNodeType.Element &&
          n.LocalName == XmlSignature.ElementNames.Reference &&
          n.NamespaceURI == XmlSignature.NamespaceURI) {
          Reference r = new Reference ();
          r.LoadXml ((XmlElement) n);
          AddReference (r);
        }
      }
      element = value;
    }
  }
}