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