class/corlib/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) 2004-2005 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 && !MOONLIGHT
  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                 protected 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 (Locale.GetText ("Invalid X.509 extension."));
  64                         if (asn1[0].Tag != 0x06)
  65                                 throw new ArgumentException (Locale.GetText ("Invalid X.509 extension."));
  66
  67                         extnOid = ASN1Convert.ToOid (asn1[0]);
  68                         extnCritical = ((asn1[1].Tag == 0x01) && (asn1[1].Value[0] == 0xFF));
  69                         // last element is an octet string which may need to be decoded
  70                         extnValue = asn1 [asn1.Count - 1];
  71                         if ((extnValue.Tag == 0x04) && (extnValue.Length > 0) && (extnValue.Count == 0)) {
  72                                 try {
  73                                         ASN1 encapsulated = new ASN1 (extnValue.Value);
  74                                         extnValue.Value = null;
  75                                         extnValue.Add (encapsulated);
  76                                 }
  77                                 catch {
  78                                         // data isn't ASN.1
  79                                 }
  80                         }
  81                         Decode ();
  82                 }
  83
  84                 public X509Extension (X509Extension extension)
  85                 {
  86                         if (extension == null)
  87                                 throw new ArgumentNullException ("extension");
  88                         if ((extension.Value == null) || (extension.Value.Tag != 0x04) || (extension.Value.Count != 1))
  89                                 throw new ArgumentException (Locale.GetText ("Invalid X.509 extension."));
  90
  91                         extnOid = extension.Oid;
  92                         extnCritical = extension.Critical;
  93                         extnValue = extension.Value;
  94                         Decode ();
  95                 }
  96
  97                 // encode the extension *into* an OCTET STRING
  98                 protected virtual void Decode ()
  99                 {
 100                 }
 101
 102                 // decode the extension from *inside* an OCTET STRING
 103                 protected virtual void Encode ()
 104                 {
 105                 }
 106
 107                 public ASN1 ASN1 {
 108                         get {
 109                                 ASN1 extension = new ASN1 (0x30);
 110                                 extension.Add (ASN1Convert.FromOid (extnOid));
 111                                 if (extnCritical)
 112                                         extension.Add (new ASN1 (0x01, new byte [1] { 0xFF }));
 113                                 Encode ();
 114                                 extension.Add (extnValue);
 115                                 return extension;
 116                         }
 117                 }
 118
 119                 public string Oid {
 120                         get { return extnOid; }
 121                 }
 122
 123                 public bool Critical {
 124                         get { return extnCritical; }
 125                         set { extnCritical = value; }
 126                 }
 127
 128                 // this gets overrided with more meaningful names
 129                 public virtual string Name {
 130                         get { return extnOid; }
 131                 }
 132
 133                 public ASN1 Value {
 134                         get {
 135                                 if (extnValue == null) {
 136                                         Encode ();
 137                                 }
 138                                 return extnValue;
 139                         }
 140                 }
 141
 142                 public override bool Equals (object obj)
 143                 {
 144                         if (obj == null)
 145                                 return false;
 146
 147                         X509Extension ex = (obj as X509Extension);
 148                         if (ex == null)
 149                                 return false;
 150
 151                         if (extnCritical != ex.extnCritical)
 152                                 return false;
 153                         if (extnOid != ex.extnOid)
 154                                 return false;
 155                         if (extnValue.Length != ex.extnValue.Length)
 156                                 return false;
 157
 158                         for (int i=0; i < extnValue.Length; i++) {
 159                                 if (extnValue [i] != ex.extnValue [i])
 160                                         return false;
 161                         }
 162                         return true;
 163                 }
 164
 165                 public byte[] GetBytes ()
 166                 {
 167                         return ASN1.GetBytes ();
 168                 }
 169
 170                 public override int GetHashCode ()
 171                 {
 172                         // OID should be unique in a collection of extensions
 173                         return extnOid.GetHashCode ();
 174                 }
 175
 176                 private void WriteLine (StringBuilder sb, int n, int pos)
 177                 {
 178                         byte[] value = extnValue.Value;
 179                         int p = pos;
 180                         for (int j=0; j < 8; j++) {
 181                                 if (j < n) {
 182                                         sb.Append (value [p++].ToString ("X2", CultureInfo.InvariantCulture));
 183                                         sb.Append (" ");
 184                                 }
 185                                 else
 186                                         sb.Append ("   ");
 187                         }
 188                         sb.Append ("  ");
 189                         p = pos;
 190                         for (int j=0; j < n; j++) {
 191                                 byte b = value [p++];
 192                                 if (b < 0x20)
 193                                         sb.Append (".");
 194                                 else
 195                                         sb.Append (Convert.ToChar (b));
 196                         }
 197                         sb.Append (Environment.NewLine);
 198                 }
 199
 200                 public override string ToString ()
 201                 {
 202                         StringBuilder sb = new StringBuilder ();
 203                         int div = (extnValue.Length >> 3);
 204                         int rem = (extnValue.Length - (div << 3));
 205                         int x = 0;
 206                         for (int i=0; i < div; i++) {
 207                                 WriteLine (sb, 8, x);
 208                                 x += 8;
 209                         }
 210                         WriteLine (sb, rem, x);
 211                         return sb.ToString ();
 212                 }
 213         }
 214 }