mcs/class/Mono.Security/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 // 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 using System;
  33 using System.Globalization;
  34 using System.Text;
  35
  36 using Mono.Security;
  37 using Mono.Security.X509;
  38
  39 namespace Mono.Security.X509.Extensions {
  40
  41         // References:
  42         // 1.   RFC 3280: Internet X.509 Public Key Infrastructure, Section 4.2.1.10
  43         //      http://www.ietf.org/rfc/rfc3280.txt
  44
  45         /* id-ce-basicConstraints OBJECT IDENTIFIER ::=  { id-ce 19 }
  46          *
  47          * BasicConstraints ::= SEQUENCE {
  48          *      cA                      BOOLEAN DEFAULT FALSE,
  49          *      pathLenConstraint       INTEGER (0..MAX) OPTIONAL
  50          * }
  51          */
  52 #if INSIDE_CORLIB
  53         internal
  54 #else
  55         public
  56 #endif
  57         class BasicConstraintsExtension : X509Extension {
  58
  59                 private bool cA;
  60                 private int pathLenConstraint;
  61
  62                 public BasicConstraintsExtension () : base ()
  63                 {
  64                         extnOid = "2.5.29.19";
  65                 }
  66
  67                 public BasicConstraintsExtension (ASN1 asn1) : base (asn1) {}
  68
  69                 public BasicConstraintsExtension (X509Extension extension) : base (extension) {}
  70
  71                 protected override void Decode ()
  72                 {
  73                         // default values
  74                         cA = false;
  75                         pathLenConstraint = 0; // no constraint
  76
  77                         ASN1 sequence = new ASN1 (extnValue.Value);
  78                         if (sequence.Tag != 0x30)
  79                                 throw new ArgumentException ("Invalid BasicConstraints extension");
  80                         int n = 0;
  81                         ASN1 a = sequence [n++];
  82                         if ((a != null) && (a.Tag == 0x01)) {
  83                                 cA = (a.Value [0] == 0xFF);
  84                                 a = sequence [n++];
  85                         }
  86                         if ((a != null) && (a.Tag == 0x02))
  87                                 pathLenConstraint = ASN1Convert.ToInt32 (a);
  88                 }
  89
  90                 protected override void Encode ()
  91                 {
  92                         if (extnValue == null) {
  93                                 extnValue = new ASN1 (0x30);
  94                                 if (cA)
  95                                         extnValue.Add (new ASN1 (0x01, new byte[] { 0xFF }));
  96                                 if (pathLenConstraint > 0)
  97                                         extnValue.Add (ASN1Convert.FromInt32 (pathLenConstraint));
  98                         }
  99                 }
 100
 101                 public bool CertificateAuthority {
 102                         get { return cA; }
 103                         set { cA = value; }
 104                 }
 105
 106                 public override string Name {
 107                         get { return "Basic Constraints"; }
 108                 }
 109
 110                 public int PathLenConstraint {
 111                         get { return pathLenConstraint; }
 112                         set { pathLenConstraint = value; }
 113                 }
 114
 115                 public override string ToString ()
 116                 {
 117                         StringBuilder sb = new StringBuilder ();
 118                         sb.Append ("Subject Type=");
 119                         sb.Append ((cA) ? "CA" : "End Entity");
 120                         sb.Append (Environment.NewLine);
 121                         sb.Append ("Path Length Constraint=");
 122                         if (pathLenConstraint == 0)
 123                                 sb.Append ("None");
 124                         else
 125                                 sb.Append (pathLenConstraint.ToString (CultureInfo.InvariantCulture));
 126                         sb.Append (Environment.NewLine);
 127                         return sb.ToString ();
 128                 }
 129         }
 130 }