mcs/class/Mono.Security/Mono.Security.X509.Extensions/KeyAttributesExtension.cs

   1 //
   2 // KeyAttributesExtension.cs: Handles X.509 *DEPRECATED* KeyAttributes extensions.
   3 //
   4 // Author:
   5 //      Sebastien Pouliot (spouliot@motus.com)
   6 //
   7 // (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   8 //
   9
  10 using System;
  11 using System.Text;
  12
  13 using Mono.Security;
  14 using Mono.Security.X509;
  15
  16 namespace Mono.Security.X509.Extensions {
  17         // definition found @ http://groups.yahoo.com/group/ssl-talk/message/1964
  18         //
  19         // keyAttributes EXTENSION ::= {
  20         //      SYNTAX KeyAttributes
  21         //      IDENTIFIED BY { id-ce 2 } }
  22         //
  23         // KeyAttributes ::= SEQUENCE {
  24         //      keyIdentifier KeyIdentifier OPTIONAL,
  25         //      intendedKeyUsage KeyUsage OPTIONAL,
  26         //      privateKeyUsagePeriod PrivateKeyValidity OPTIONAL
  27         // }
  28         // KeyUsage ::= BIT STRING {
  29         //      digitalSignature (0),
  30         //      nonRepudiation (1),
  31         //      keyEncipherment (2),
  32         //      dataEncipherment (3),
  33         //      keyAgreement (4),
  34         //      keyCertSign (5),
  35         //      offLineCRLSign (6)
  36         // }
  37         // PrivateKeyValidity ::= SEQUENCE {
  38         //      notBefore [0] GeneralizedTime OPTIONAL,
  39         //      notAfter [1] GeneralizedTime OPTIONAL
  40         // }
  41         // ( CONSTRAINED BY { -- at least one component shall be present -- })
  42
  43         public class KeyAttributesExtension : X509Extension {
  44
  45                 private byte[] keyId;
  46                 private int kubits;
  47                 private DateTime notBefore;
  48                 private DateTime notAfter;
  49
  50                 public KeyAttributesExtension () : base ()
  51                 {
  52                         extnOid = "2.5.29.2";
  53                 }
  54
  55                 public KeyAttributesExtension (ASN1 asn1) : base (asn1) {}
  56
  57                 public KeyAttributesExtension (X509Extension extension) : base (extension) {}
  58
  59                 protected override void Decode ()
  60                 {
  61                         ASN1 seq = new ASN1 (extnValue.Value);
  62                         if (seq.Tag != 0x30)
  63                                 throw new ArgumentException ("Invalid KeyAttributesExtension extension");
  64                         int n = 0;
  65                         // check for KeyIdentifier
  66                         if (n < seq.Count) {
  67                                 ASN1 item = seq [n];
  68                                 if (item.Tag == 0x04) {
  69                                         n++;
  70                                         keyId = item.Value;
  71                                 }
  72                         }
  73                         // check for KeyUsage
  74                         if (n < seq.Count) {
  75                                 ASN1 item = seq [n];
  76                                 if (item.Tag == 0x03) {
  77                                         n++;
  78                                         int i = 1; // byte zero has the number of unused bits (ASN1's BITSTRING)
  79                                         while (i < item.Value.Length)
  80                                                 kubits = (kubits << 8) + item.Value [i++];
  81                                 }
  82                         }
  83                         // check for PrivateKeyValidity
  84                         if (n < seq.Count) {
  85                                 ASN1 item = seq [n];
  86                                 if (item.Tag == 0x30) {
  87                                         int i = 0;
  88                                         if (i < item.Count) {
  89                                                 ASN1 dt = item [i];
  90                                                 if (dt.Tag == 0x81) {
  91                                                         i++;
  92                                                         notBefore = ASN1Convert.ToDateTime (dt);
  93                                                 }
  94                                         }
  95                                         if (i < item.Count) {
  96                                                 ASN1 dt = item [i];
  97                                                 if (dt.Tag == 0x82)
  98                                                         notAfter = ASN1Convert.ToDateTime (dt);
  99                                         }
 100                                 }
 101                         }
 102                 }
 103
 104                 public byte[] KeyIdentifier {
 105                         get { return keyId; }
 106                 }
 107
 108                 public override string Name {
 109                         get { return "Key Attributes"; }
 110                 }
 111
 112                 public DateTime NotAfter {
 113                         get { return notAfter; }
 114                 }
 115
 116                 public DateTime NotBefore {
 117                         get { return notBefore; }
 118                 }
 119
 120                 public bool Support (KeyUsage usage)
 121                 {
 122                         int x = Convert.ToInt32 (usage);
 123                         return ((x & kubits) == x);
 124                 }
 125
 126                 public override string ToString ()
 127                 {
 128                         StringBuilder sb = new StringBuilder ();
 129                         if (keyId != null) {
 130                                 sb.Append ("KeyID=");
 131                                 int x = 0;
 132                                 while (x < keyId.Length) {
 133                                         sb.Append (keyId [x].ToString ("X2"));
 134                                         if (x % 2 == 1)
 135                                                 sb.Append (" ");
 136                                         x++;
 137                                 }
 138                                 sb.Append (Environment.NewLine);
 139                         }
 140
 141                         if (kubits != 0) {
 142                                 sb.Append ("Key Usage=");
 143                                 const string separator = " , ";
 144                                 if (Support (KeyUsage.digitalSignature))
 145                                         sb.Append ("Digital Signature");
 146                                 if (Support (KeyUsage.nonRepudiation)) {
 147                                         if (sb.Length > 0)
 148                                                 sb.Append (separator);
 149                                         sb.Append ("Non-Repudiation");
 150                                 }
 151                                 if (Support (KeyUsage.keyEncipherment)) {
 152                                         if (sb.Length > 0)
 153                                                 sb.Append (separator);
 154                                         sb.Append ("Key Encipherment");
 155                                 }
 156                                 if (Support (KeyUsage.dataEncipherment)) {
 157                                         if (sb.Length > 0)
 158                                                 sb.Append (separator);
 159                                         sb.Append ("Data Encipherment");
 160                                 }
 161                                 if (Support (KeyUsage.keyAgreement)) {
 162                                         if (sb.Length > 0)
 163                                                 sb.Append (separator);
 164                                         sb.Append ("Key Agreement");
 165                                 }
 166                                 if (Support (KeyUsage.keyCertSign)) {
 167                                         if (sb.Length > 0)
 168                                                 sb.Append (separator);
 169                                         sb.Append ("Certificate Signing");
 170                                 }
 171                                 if (Support (KeyUsage.cRLSign)) {
 172                                         if (sb.Length > 0)
 173                                                 sb.Append (separator);
 174                                         sb.Append ("CRL Signing");
 175                                 }
 176                                 if (Support (KeyUsage.encipherOnly)) {
 177                                         if (sb.Length > 0)
 178                                                 sb.Append (separator);
 179                                         sb.Append ("Encipher Only ");   // ???
 180                                 }
 181                                 if (Support (KeyUsage.decipherOnly)) {
 182                                         if (sb.Length > 0)
 183                                                 sb.Append (separator);
 184                                         sb.Append ("Decipher Only");    // ???
 185                                 }
 186                                 sb.Append ("(");
 187                                 sb.Append (kubits.ToString ("X2"));
 188                                 sb.Append (")");
 189                                 sb.Append (Environment.NewLine);
 190                         }
 191
 192                         if (notBefore != DateTime.MinValue) {
 193                                 sb.Append ("Not Before=");
 194                                 sb.Append (notBefore.ToString ());
 195                                 sb.Append (Environment.NewLine);
 196                         }
 197                         if (notAfter != DateTime.MinValue) {
 198                                 sb.Append ("Not After=");
 199                                 sb.Append (notAfter.ToString ());
 200                                 sb.Append (Environment.NewLine);
 201                         }
 202                         return sb.ToString ();
 203                 }
 204         }
 205 }