mcs/class/corlib/Mono.Security.X509.Extensions/BasicConstraintsExtension.cs

   1 //
   2 // BasicConstraintsExtension.cs: Handles X.509 BasicConstrains extensions.
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   8 // (C) 2004 Novell (http://www.novell.com)
   9 //
  10
  11 //
  12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 using System;
  35 using System.Globalization;
  36 using System.Text;
  37
  38 using Mono.Security;
  39 using Mono.Security.X509;
  40
  41 namespace Mono.Security.X509.Extensions {
  42
  43         // References:
  44         // 1.   RFC 3280: Internet X.509 Public Key Infrastructure, Section 4.2.1.10
  45         //      http://www.ietf.org/rfc/rfc3280.txt
  46
  47         /* id-ce-basicConstraints OBJECT IDENTIFIER ::=  { id-ce 19 }
  48          *
  49          * BasicConstraints ::= SEQUENCE {
  50          *      cA                      BOOLEAN DEFAULT FALSE,
  51          *      pathLenConstraint       INTEGER (0..MAX) OPTIONAL
  52          * }
  53          */
  54 #if INSIDE_CORLIB
  55         internal
  56 #else
  57         public
  58 #endif
  59         class BasicConstraintsExtension : X509Extension {
  60
  61                 private bool cA;
  62                 private int pathLenConstraint;
  63
  64                 public BasicConstraintsExtension () : base ()
  65                 {
  66                         extnOid = "2.5.29.19";
  67                 }
  68
  69                 public BasicConstraintsExtension (ASN1 asn1) : base (asn1) {}
  70
  71                 public BasicConstraintsExtension (X509Extension extension) : base (extension) {}
  72
  73                 protected override void Decode ()
  74                 {
  75                         // default values
  76                         cA = false;
  77                         pathLenConstraint = 0; // no constraint
  78
  79                         ASN1 sequence = new ASN1 (extnValue.Value);
  80                         if (sequence.Tag != 0x30)
  81                                 throw new ArgumentException ("Invalid BasicConstraints extension");
  82                         int n = 0;
  83                         ASN1 a = sequence [n++];
  84                         if ((a != null) && (a.Tag == 0x01)) {
  85                                 cA = (a.Value [0] == 0xFF);
  86                                 a = sequence [n++];
  87                         }
  88                         if ((a != null) && (a.Tag == 0x02))
  89                                 pathLenConstraint = ASN1Convert.ToInt32 (a);
  90                 }
  91
  92                 protected override void Encode ()
  93                 {
  94                         if (extnValue == null) {
  95                                 extnValue = new ASN1 (0x30);
  96                                 if (cA)
  97                                         extnValue.Add (new ASN1 (0x01, new byte[] { 0xFF }));
  98                                 if (pathLenConstraint > 0)
  99                                         extnValue.Add (ASN1Convert.FromInt32 (pathLenConstraint));
 100                         }
 101                 }
 102
 103                 public bool CertificateAuthority {
 104                         get { return cA; }
 105                         set { cA = value; }
 106                 }
 107
 108                 public override string Name {
 109                         get { return "Basic Constraints"; }
 110                 }
 111
 112                 public int PathLenConstraint {
 113                         get { return pathLenConstraint; }
 114                         set { pathLenConstraint = value; }
 115                 }
 116
 117                 public override string ToString ()
 118                 {
 119                         StringBuilder sb = new StringBuilder ();
 120                         sb.Append ("Subject Type=");
 121                         sb.Append ((cA) ? "CA" : "End Entity");
 122                         sb.Append (Environment.NewLine);
 123                         sb.Append ("Path Length Constraint=");
 124                         if (pathLenConstraint == 0)
 125                                 sb.Append ("None");
 126                         else
 127                                 sb.Append (pathLenConstraint.ToString (CultureInfo.InvariantCulture));
 128                         sb.Append (Environment.NewLine);
 129                         return sb.ToString ();
 130                 }
 131         }
 132 }