mcs/class/Mono.Security/Mono.Security.X509/X509Extension.cs

   1 //
   2 // X509Extension.cs: Base class for all X.509 extensions.
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   8 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System;
  31 using System.Globalization;
  32 using System.Text;
  33
  34 using Mono.Security;
  35
  36 namespace Mono.Security.X509 {
  37         /*
  38          * Extension  ::=  SEQUENCE  {
  39          *      extnID      OBJECT IDENTIFIER,
  40          *      critical    BOOLEAN DEFAULT FALSE,
  41          *      extnValue   OCTET STRING
  42          * }
  43          */
  44 #if INSIDE_CORLIB
  45         internal
  46 #else
  47         public
  48 #endif
  49         class X509Extension {
  50
  51                 protected string extnOid;
  52                 protected bool extnCritical;
  53                 protected ASN1 extnValue;
  54
  55                 internal X509Extension ()
  56                 {
  57                         extnCritical = false;
  58                 }
  59
  60                 public X509Extension (ASN1 asn1)
  61                 {
  62                         if ((asn1.Tag != 0x30) || (asn1.Count < 2))
  63                                 throw new ArgumentException ("Invalid X.509 extension");
  64                         if (asn1[0].Tag != 0x06)
  65                                 throw new ArgumentException ("Invalid X.509 extension");
  66                         extnOid = ASN1Convert.ToOid (asn1 [0]);
  67                         extnCritical = ((asn1[1].Tag == 0x01) && (asn1[1].Value[0] == 0xFF));
  68                         extnValue = asn1 [asn1.Count - 1]; // last element
  69                         Decode ();
  70                 }
  71
  72                 public X509Extension (X509Extension extension) : this ()
  73                 {
  74                         if (extension == null)
  75                                 throw new ArgumentNullException ("extension");
  76                         if ((extension.Value.Tag != 0x04) || (extension.Value.Count != 0))
  77                                 throw new ArgumentException ("Invalid extension");
  78                         extnOid = extension.Oid;
  79                         extnCritical = extension.Critical;
  80                         extnValue = extension.Value;
  81                         Decode ();
  82                 }
  83
  84                 protected virtual void Decode ()
  85                 {
  86                 }
  87
  88                 protected virtual void Encode ()
  89                 {
  90                 }
  91
  92                 public ASN1 ASN1 {
  93                         get {
  94                                 ASN1 extension = new ASN1 (0x30);
  95                                 extension.Add (ASN1Convert.FromOid (extnOid));
  96                                 if (extnCritical)
  97                                         extension.Add (new ASN1 (0x01, new byte [1] { 0x01 }));
  98                                 ASN1 os = extension.Add (new ASN1 (0x04));
  99                                 Encode ();
 100                                 os.Add (extnValue);
 101                                 return extension;
 102                         }
 103                 }
 104
 105                 public string Oid {
 106                         get { return extnOid; }
 107                 }
 108
 109                 public bool Critical {
 110                         get { return extnCritical; }
 111                 }
 112
 113                 // this gets overrided with more meaningful names
 114                 public virtual string Name {
 115                         get { return extnOid; }
 116                 }
 117
 118                 public ASN1 Value {
 119                         get { return extnValue; }
 120                 }
 121
 122                 public override bool Equals (object obj)
 123                 {
 124                         if (obj == null)
 125                                 return false;
 126
 127                         X509Extension ex = (obj as X509Extension);
 128                         if (ex == null)
 129                                 return false;
 130
 131                         if (extnCritical != ex.extnCritical)
 132                                 return false;
 133                         if (extnOid != ex.extnOid)
 134                                 return false;
 135                         if (extnValue.Length != ex.extnValue.Length)
 136                                 return false;
 137
 138                         for (int i=0; i < extnValue.Length; i++) {
 139                                 if (extnValue [i] != ex.extnValue [i])
 140                                         return false;
 141                         }
 142                         return true;
 143                 }
 144
 145                 public byte[] GetBytes ()
 146                 {
 147                         return ASN1.GetBytes ();
 148                 }
 149
 150                 public override int GetHashCode ()
 151                 {
 152                         // OID should be unique in a collection of extensions
 153                         return extnOid.GetHashCode ();
 154                 }
 155
 156                 private void WriteLine (StringBuilder sb, int n, int pos)
 157                 {
 158                         byte[] value = extnValue.Value;
 159                         int p = pos;
 160                         for (int j=0; j < 8; j++) {
 161                                 if (j < n) {
 162                                         sb.Append (value [p++].ToString ("X2", CultureInfo.InvariantCulture));
 163                                         sb.Append (" ");
 164                                 }
 165                                 else
 166                                         sb.Append ("   ");
 167                         }
 168                         sb.Append ("  ");
 169                         p = pos;
 170                         for (int j=0; j < n; j++) {
 171                                 byte b = value [p++];
 172                                 if (b < 0x20)
 173                                         sb.Append (".");
 174                                 else
 175                                         sb.Append (Convert.ToChar (b));
 176                         }
 177                         sb.Append (Environment.NewLine);
 178                 }
 179
 180                 public override string ToString ()
 181                 {
 182                         StringBuilder sb = new StringBuilder ();
 183                         int div = (extnValue.Length >> 3);
 184                         int rem = (extnValue.Length - (div << 3));
 185                         int x = 0;
 186                         for (int i=0; i < div; i++) {
 187                                 WriteLine (sb, 8, x);
 188                                 x += 8;
 189                         }
 190                         WriteLine (sb, rem, x);
 191                         return sb.ToString ();
 192                 }
 193         }
 194 }