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
  33
  34 #if MONOTOUCH || MONODROID
  35 using Mono.Security;
  36 #else
  37 extern alias MonoSecurity;
  38 using MonoSecurity::Mono.Security;
  39 #endif
  40
  41 using System.Text;
  42
  43 namespace System.Security.Cryptography.X509Certificates {
  44
  45         public sealed class X509BasicConstraintsExtension : X509Extension {
  46
  47                 internal const string oid = "2.5.29.19";
  48                 internal const string friendlyName = "Basic Constraints";
  49
  50                 private bool _certificateAuthority;
  51                 private bool _hasPathLengthConstraint;
  52                 private int _pathLengthConstraint;
  53                 private AsnDecodeStatus _status;
  54
  55                 // constructors
  56
  57                 public X509BasicConstraintsExtension ()
  58                 {
  59                         _oid = new Oid (oid, friendlyName);
  60                 }
  61
  62                 public X509BasicConstraintsExtension (AsnEncodedData encodedBasicConstraints, bool critical)
  63                 {
  64                         // ignore the Oid provided by encodedKeyUsage (our rules!)
  65                         _oid = new Oid (oid, friendlyName);
  66                         _raw = encodedBasicConstraints.RawData;
  67                         base.Critical = critical;
  68                         _status = Decode (this.RawData);
  69                 }
  70
  71                 public X509BasicConstraintsExtension (bool certificateAuthority, bool hasPathLengthConstraint, int pathLengthConstraint, bool critical)
  72                 {
  73                         if (hasPathLengthConstraint) {
  74                                 if (pathLengthConstraint < 0)
  75                                         throw new ArgumentOutOfRangeException ("pathLengthConstraint");
  76                                 _pathLengthConstraint = pathLengthConstraint;
  77                         }
  78                         _hasPathLengthConstraint = hasPathLengthConstraint;
  79                         _certificateAuthority = certificateAuthority;
  80                         _oid = new Oid (oid, friendlyName);
  81                         base.Critical = critical;
  82                         RawData = Encode ();
  83                 }
  84
  85                 // properties
  86
  87                 public bool CertificateAuthority {
  88                         get {
  89                                 switch (_status) {
  90                                 case AsnDecodeStatus.Ok:
  91                                 case AsnDecodeStatus.InformationNotAvailable:
  92                                         return _certificateAuthority;
  93                                 default:
  94                                         throw new CryptographicException ("Badly encoded extension.");
  95                                 }
  96                         }
  97                 }
  98
  99                 public bool HasPathLengthConstraint {
 100                         get {
 101                                 switch (_status) {
 102                                 case AsnDecodeStatus.Ok:
 103                                 case AsnDecodeStatus.InformationNotAvailable:
 104                                         return _hasPathLengthConstraint;
 105                                 default:
 106                                         throw new CryptographicException ("Badly encoded extension.");
 107                                 }
 108                         }
 109                 }
 110
 111                 public int PathLengthConstraint {
 112                         get {
 113                                 switch (_status) {
 114                                 case AsnDecodeStatus.Ok:
 115                                 case AsnDecodeStatus.InformationNotAvailable:
 116                                         return _pathLengthConstraint;
 117                                 default:
 118                                         throw new CryptographicException ("Badly encoded extension.");
 119                                 }
 120                         }
 121                 }
 122
 123                 // methods
 124
 125                 public override void CopyFrom (AsnEncodedData asnEncodedData)
 126                 {
 127                         if (asnEncodedData == null)
 128                                 throw new ArgumentNullException ("asnEncodedData");
 129
 130                         X509Extension ex = (asnEncodedData as X509Extension);
 131                         if (ex == null)
 132                                 throw new ArgumentException (Locale.GetText ("Wrong type."), "asnEncodedData");
 133
 134                         if (ex._oid == null)
 135                                 _oid = new Oid (oid, friendlyName);
 136                         else
 137                                 _oid = new Oid (ex._oid);
 138
 139                         RawData = ex.RawData;
 140                         base.Critical = ex.Critical;
 141                         // and we deal with the rest later
 142                         _status = Decode (this.RawData);
 143                 }
 144
 145                 // internal
 146
 147                 internal AsnDecodeStatus Decode (byte[] extension)
 148                 {
 149                         if ((extension == null) || (extension.Length == 0))
 150                                 return AsnDecodeStatus.BadAsn;
 151                         if (extension [0] != 0x30)
 152                                 return AsnDecodeStatus.BadTag;
 153                         if (extension.Length < 3) {
 154                                 if (!((extension.Length == 2) && (extension [1] == 0x00)))
 155                                         return AsnDecodeStatus.BadLength;
 156                         }
 157
 158                         try {
 159                                 ASN1 sequence = new ASN1 (extension);
 160                                 int n = 0;
 161                                 ASN1 a = sequence [n++];
 162                                 if ((a != null) && (a.Tag == 0x01)) {
 163                                         _certificateAuthority = (a.Value [0] == 0xFF);
 164                                         a = sequence [n++];
 165                                 }
 166                                 if ((a != null) && (a.Tag == 0x02)) {
 167                                         _hasPathLengthConstraint = true;
 168                                         _pathLengthConstraint = ASN1Convert.ToInt32 (a);
 169                                 }
 170                         }
 171                         catch {
 172                                 return AsnDecodeStatus.BadAsn;
 173                         }
 174
 175                         return AsnDecodeStatus.Ok;
 176                 }
 177
 178                 internal byte[] Encode ()
 179                 {
 180                         ASN1 ex = new ASN1 (0x30);
 181
 182                         if (_certificateAuthority)
 183                                 ex.Add (new ASN1 (0x01, new byte[] { 0xFF }));
 184                         if (_hasPathLengthConstraint) {
 185                                 // MS encodes the 0 (pathLengthConstraint is OPTIONAL)
 186                                 // and in a long form (02 00 versus 02 01 00)
 187                                 if (_pathLengthConstraint == 0)
 188                                         ex.Add (new ASN1 (0x02, new byte[] { 0x00 }));
 189                                 else
 190                                         ex.Add (ASN1Convert.FromInt32 (_pathLengthConstraint));
 191                         }
 192
 193                         return ex.GetBytes ();
 194                 }
 195
 196                 internal override string ToString (bool multiLine)
 197                 {
 198                         switch (_status) {
 199                         case AsnDecodeStatus.BadAsn:
 200                                 return String.Empty;
 201                         case AsnDecodeStatus.BadTag:
 202                         case AsnDecodeStatus.BadLength:
 203                                 return FormatUnkownData (_raw);
 204                         case AsnDecodeStatus.InformationNotAvailable:
 205                                 return "Information Not Available";
 206                         }
 207
 208                         if (_oid.Value != oid)
 209                                 return String.Format ("Unknown Key Usage ({0})", _oid.Value);
 210
 211                         StringBuilder sb = new StringBuilder ();
 212
 213                         sb.Append ("Subject Type=");
 214                         if (_certificateAuthority)
 215                                 sb.Append ("CA");
 216                         else
 217                                 sb.Append ("End Entity");
 218                         if (multiLine)
 219                                 sb.Append (Environment.NewLine);
 220                         else
 221                                 sb.Append (", ");
 222
 223                         sb.Append ("Path Length Constraint=");
 224                         if (_hasPathLengthConstraint)
 225                                 sb.Append (_pathLengthConstraint);
 226                         else
 227                                 sb.Append ("None");
 228                         if (multiLine)
 229                                 sb.Append (Environment.NewLine);
 230
 231                         return sb.ToString ();
 232                 }
 233         }
 234 }
 235
 236 #endif