mcs/class/System.Security/System.Security.Cryptography.Xml/Signature.cs

   1 //
   2 // Signature.cs - Signature implementation for XML Signature
   3 //
   4 // Author:
   5 //      Sebastien Pouliot (spouliot@motus.com)
   6 //
   7 // (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Collections;
  32 using System.Security.Cryptography;
  33 using System.Xml;
  34
  35 namespace System.Security.Cryptography.Xml {
  36
  37         public class Signature {
  38                 static XmlNamespaceManager dsigNsmgr;
  39
  40                 static Signature ()
  41                 {
  42                         dsigNsmgr = new XmlNamespaceManager (new NameTable ());
  43                         dsigNsmgr.AddNamespace ("xd", XmlSignature.NamespaceURI);
  44                 }
  45
  46                 private ArrayList list;
  47                 private SignedInfo info;
  48                 private KeyInfo key;
  49                 private string id;
  50                 private byte[] signature;
  51                 private XmlElement element;
  52
  53                 public Signature ()
  54                 {
  55                         list = new ArrayList ();
  56                 }
  57
  58                 public string Id {
  59                         get { return id; }
  60                         set {
  61                                 element = null;
  62                                 id = value;
  63                         }
  64                 }
  65
  66                 public KeyInfo KeyInfo {
  67                         get { return key; }
  68                         set {
  69                                 element = null;
  70                                 key = value;
  71                         }
  72                 }
  73
  74                 public IList ObjectList {
  75                         get { return list; }
  76                         set { list = ArrayList.Adapter (value); }
  77                 }
  78
  79                 public byte[] SignatureValue {
  80                         get { return signature; }
  81                         set {
  82                                 element = null;
  83                                 signature = value;
  84                         }
  85                 }
  86
  87                 public SignedInfo SignedInfo {
  88                         get { return info; }
  89                         set {
  90                                 element = null;
  91                                 info = value;
  92                         }
  93                 }
  94
  95                 public void AddObject (DataObject dataObject)
  96                 {
  97                         list.Add (dataObject);
  98                 }
  99
 100                 public XmlElement GetXml ()
 101                 {
 102                         if (element != null)
 103                                 return element;
 104
 105                         if (info == null)
 106                                 throw new CryptographicException ("SignedInfo");
 107                         if (signature == null)
 108                                 throw new CryptographicException ("SignatureValue");
 109
 110                         XmlDocument document = new XmlDocument ();
 111                         XmlElement xel = document.CreateElement (XmlSignature.ElementNames.Signature, XmlSignature.NamespaceURI);
 112                         if (id != null)
 113                                 xel.SetAttribute (XmlSignature.AttributeNames.Id, id);
 114
 115                         XmlNode xn = info.GetXml ();
 116                         XmlNode newNode = document.ImportNode (xn, true);
 117                         xel.AppendChild (newNode);
 118
 119                         if (signature != null) {
 120                                 XmlElement sv = document.CreateElement (XmlSignature.ElementNames.SignatureValue, XmlSignature.NamespaceURI);
 121                                 sv.InnerText = Convert.ToBase64String (signature);
 122                                 xel.AppendChild (sv);
 123                         }
 124
 125                         if (key != null) {
 126                                 xn = key.GetXml ();
 127                                 newNode = document.ImportNode (xn, true);
 128                                 xel.AppendChild (newNode);
 129                         }
 130
 131                         if (list.Count > 0) {
 132                                 foreach (DataObject obj in list) {
 133                                         xn = obj.GetXml ();
 134                                         newNode = document.ImportNode (xn, true);
 135                                         xel.AppendChild (newNode);
 136                                 }
 137                         }
 138
 139                         return xel;
 140                 }
 141
 142                 private string GetAttribute (XmlElement xel, string attribute)
 143                 {
 144                         XmlAttribute xa = xel.Attributes [attribute];
 145                         return ((xa != null) ? xa.InnerText : null);
 146                 }
 147
 148                 public void LoadXml (XmlElement value)
 149                 {
 150                         if (value == null)
 151                                 throw new ArgumentNullException ("value");
 152
 153                         if ((value.LocalName == XmlSignature.ElementNames.Signature) && (value.NamespaceURI == XmlSignature.NamespaceURI)) {
 154                                 id = GetAttribute (value, XmlSignature.AttributeNames.Id);
 155
 156                                 // LAMESPEC: This library is totally useless against eXtensibly Marked-up document.
 157                                 int i = NextElementPos (value.ChildNodes, 0, XmlSignature.ElementNames.SignedInfo, XmlSignature.NamespaceURI, true);
 158                                 XmlElement sinfo = (XmlElement) value.ChildNodes [i];
 159                                 info = new SignedInfo ();
 160                                 info.LoadXml (sinfo);
 161
 162                                 i = NextElementPos (value.ChildNodes, ++i, XmlSignature.ElementNames.SignatureValue, XmlSignature.NamespaceURI, true);
 163                                 XmlElement sigValue = (XmlElement) value.ChildNodes [i];
 164                                 signature = Convert.FromBase64String (sigValue.InnerText);
 165
 166                                 // signature isn't required: <element ref="ds:KeyInfo" minOccurs="0"/>
 167                                 i = NextElementPos (value.ChildNodes, ++i, XmlSignature.ElementNames.KeyInfo, XmlSignature.NamespaceURI, false);
 168                                 if (i > 0) {
 169                                         XmlElement kinfo = (XmlElement) value.ChildNodes [i];
 170                                         key = new KeyInfo ();
 171                                         key.LoadXml (kinfo);
 172                                 }
 173
 174                                 XmlNodeList xnl = value.SelectNodes ("xd:Object", dsigNsmgr);
 175                                 foreach (XmlElement xn in xnl) {
 176                                         DataObject obj = new DataObject ();
 177                                         obj.LoadXml (xn);
 178                                         AddObject (obj);
 179                                 }
 180                         }
 181                         else
 182                                 throw new CryptographicException ("Malformed element: Signature.");
 183
 184                         // if invalid
 185                         if (info == null)
 186                                 throw new CryptographicException ("SignedInfo");
 187                         if (signature == null)
 188                                 throw new CryptographicException ("SignatureValue");
 189                 }
 190
 191                 private int NextElementPos (XmlNodeList nl, int pos, string name, string ns, bool required)
 192                 {
 193                         while (pos < nl.Count) {
 194                                 if (nl [pos].NodeType == XmlNodeType.Element) {
 195                                         if (nl [pos].LocalName != name || nl [pos].NamespaceURI != ns) {
 196                                                 if (required)
 197                                                         throw new CryptographicException ("Malformed element " + name);
 198                                                 else
 199                                                         return -2;
 200                                         }
 201                                         else
 202                                                 return pos;
 203                                 }
 204                                 else
 205                                         pos++;
 206                         }
 207                         if (required)
 208                                 throw new CryptographicException ("Malformed element " + name);
 209                         return -1;
 210                 }
 211         }
 212 }