mcs/class/System/System.Security.Cryptography.X509Certificates/X509BasicConstraintsExtension.cs

   1 //
   2 // System.Security.Cryptography.X509BasicConstraintsExtension
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //      Tim Coleman (tim@timcoleman.com)
   7 //
   8 // (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   9 // Copyright (C) Tim Coleman, 2004
  10 // Copyright (C) 2005 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 #if SECURITY_DEP || MOONLIGHT
  33
  34 using System.Text;
  35
  36 using Mono.Security;
  37
  38 namespace System.Security.Cryptography.X509Certificates {
  39
  40         public sealed class X509BasicConstraintsExtension : X509Extension {
  41
  42                 internal const string oid = "2.5.29.19";
  43                 internal const string friendlyName = "Basic Constraints";
  44
  45                 private bool _certificateAuthority;
  46                 private bool _hasPathLengthConstraint;
  47                 private int _pathLengthConstraint;
  48                 private AsnDecodeStatus _status;
  49
  50                 // constructors
  51
  52                 public X509BasicConstraintsExtension ()
  53                 {
  54                         _oid = new Oid (oid, friendlyName);
  55                 }
  56
  57                 public X509BasicConstraintsExtension (AsnEncodedData encodedBasicConstraints, bool critical)
  58                 {
  59                         // ignore the Oid provided by encodedKeyUsage (our rules!)
  60                         _oid = new Oid (oid, friendlyName);
  61                         _raw = encodedBasicConstraints.RawData;
  62                         base.Critical = critical;
  63                         _status = Decode (this.RawData);
  64                 }
  65
  66                 public X509BasicConstraintsExtension (bool certificateAuthority, bool hasPathLengthConstraint, int pathLengthConstraint, bool critical)
  67                 {
  68                         if (hasPathLengthConstraint) {
  69                                 if (pathLengthConstraint < 0)
  70                                         throw new ArgumentOutOfRangeException ("pathLengthConstraint");
  71                                 _pathLengthConstraint = pathLengthConstraint;
  72                         }
  73                         _hasPathLengthConstraint = hasPathLengthConstraint;
  74                         _certificateAuthority = certificateAuthority;
  75                         _oid = new Oid (oid, friendlyName);
  76                         base.Critical = critical;
  77                         RawData = Encode ();
  78                 }
  79
  80                 // properties
  81
  82                 public bool CertificateAuthority {
  83                         get {
  84                                 switch (_status) {
  85                                 case AsnDecodeStatus.Ok:
  86                                 case AsnDecodeStatus.InformationNotAvailable:
  87                                         return _certificateAuthority;
  88                                 default:
  89                                         throw new CryptographicException ("Badly encoded extension.");
  90                                 }
  91                         }
  92                 }
  93
  94                 public bool HasPathLengthConstraint {
  95                         get {
  96                                 switch (_status) {
  97                                 case AsnDecodeStatus.Ok:
  98                                 case AsnDecodeStatus.InformationNotAvailable:
  99                                         return _hasPathLengthConstraint;
 100                                 default:
 101                                         throw new CryptographicException ("Badly encoded extension.");
 102                                 }
 103                         }
 104                 }
 105
 106                 public int PathLengthConstraint {
 107                         get {
 108                                 switch (_status) {
 109                                 case AsnDecodeStatus.Ok:
 110                                 case AsnDecodeStatus.InformationNotAvailable:
 111                                         return _pathLengthConstraint;
 112                                 default:
 113                                         throw new CryptographicException ("Badly encoded extension.");
 114                                 }
 115                         }
 116                 }
 117
 118                 // methods
 119
 120                 public override void CopyFrom (AsnEncodedData asnEncodedData)
 121                 {
 122                         if (asnEncodedData == null)
 123                                 throw new ArgumentNullException ("asnEncodedData");
 124
 125                         X509Extension ex = (asnEncodedData as X509Extension);
 126                         if (ex == null)
 127                                 throw new ArgumentException (Locale.GetText ("Wrong type."), "asnEncodedData");
 128
 129                         if (ex._oid == null)
 130                                 _oid = new Oid (oid, friendlyName);
 131                         else
 132                                 _oid = new Oid (ex._oid);
 133
 134                         RawData = ex.RawData;
 135                         base.Critical = ex.Critical;
 136                         // and we deal with the rest later
 137                         _status = Decode (this.RawData);
 138                 }
 139
 140                 // internal
 141
 142                 internal AsnDecodeStatus Decode (byte[] extension)
 143                 {
 144                         if ((extension == null) || (extension.Length == 0))
 145                                 return AsnDecodeStatus.BadAsn;
 146                         if (extension [0] != 0x30)
 147                                 return AsnDecodeStatus.BadTag;
 148                         if (extension.Length < 3) {
 149                                 if (!((extension.Length == 2) && (extension [1] == 0x00)))
 150                                         return AsnDecodeStatus.BadLength;
 151                         }
 152
 153                         try {
 154                                 ASN1 sequence = new ASN1 (extension);
 155                                 int n = 0;
 156                                 ASN1 a = sequence [n++];
 157                                 if ((a != null) && (a.Tag == 0x01)) {
 158                                         _certificateAuthority = (a.Value [0] == 0xFF);
 159                                         a = sequence [n++];
 160                                 }
 161                                 if ((a != null) && (a.Tag == 0x02)) {
 162                                         _hasPathLengthConstraint = true;
 163                                         _pathLengthConstraint = ASN1Convert.ToInt32 (a);
 164                                 }
 165                         }
 166                         catch {
 167                                 return AsnDecodeStatus.BadAsn;
 168                         }
 169
 170                         return AsnDecodeStatus.Ok;
 171                 }
 172
 173                 internal byte[] Encode ()
 174                 {
 175                         ASN1 ex = new ASN1 (0x30);
 176
 177                         if (_certificateAuthority)
 178                                 ex.Add (new ASN1 (0x01, new byte[] { 0xFF }));
 179                         if (_hasPathLengthConstraint) {
 180                                 // MS encodes the 0 (pathLengthConstraint is OPTIONAL)
 181                                 // and in a long form (02 00 versus 02 01 00)
 182                                 if (_pathLengthConstraint == 0)
 183                                         ex.Add (new ASN1 (0x02, new byte[] { 0x00 }));
 184                                 else
 185                                         ex.Add (ASN1Convert.FromInt32 (_pathLengthConstraint));
 186                         }
 187
 188                         return ex.GetBytes ();
 189                 }
 190
 191                 internal override string ToString (bool multiLine)
 192                 {
 193                         switch (_status) {
 194                         case AsnDecodeStatus.BadAsn:
 195                                 return String.Empty;
 196                         case AsnDecodeStatus.BadTag:
 197                         case AsnDecodeStatus.BadLength:
 198                                 return FormatUnkownData (_raw);
 199                         case AsnDecodeStatus.InformationNotAvailable:
 200                                 return "Information Not Available";
 201                         }
 202
 203                         if (_oid.Value != oid)
 204                                 return String.Format ("Unknown Key Usage ({0})", _oid.Value);
 205
 206                         StringBuilder sb = new StringBuilder ();
 207
 208                         sb.Append ("Subject Type=");
 209                         if (_certificateAuthority)
 210                                 sb.Append ("CA");
 211                         else
 212                                 sb.Append ("End Entity");
 213                         if (multiLine)
 214                                 sb.Append (Environment.NewLine);
 215                         else
 216                                 sb.Append (", ");
 217
 218                         sb.Append ("Path Length Constraint=");
 219                         if (_hasPathLengthConstraint)
 220                                 sb.Append (_pathLengthConstraint);
 221                         else
 222                                 sb.Append ("None");
 223                         if (multiLine)
 224                                 sb.Append (Environment.NewLine);
 225
 226                         return sb.ToString ();
 227                 }
 228         }
 229 }
 230
 231 #endif