mcs/class/System/System.Security.Cryptography.X509Certificates/PublicKey.cs

   1 //
   2 // PublicKey.cs - System.Security.Cryptography.PublicKey
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //      Tim Coleman (tim@timcoleman.com)
   7 //
   8 // (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   9 // Copyright (C) Tim Coleman, 2004
  10 // Copyright (C) 2005 Novell, Inc (http://www.novell.com)
  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 #if NET_2_0 && SECURITY_DEP
  33
  34 using Mono.Security;
  35 using MSX = Mono.Security.X509;
  36
  37 namespace System.Security.Cryptography.X509Certificates {
  38
  39         public sealed class PublicKey {
  40
  41                 private const string rsaOid = "1.2.840.113549.1.1.1";
  42                 private const string dsaOid = "1.2.840.10040.4.1";
  43
  44                 private AsymmetricAlgorithm _key;
  45                 private AsnEncodedData _keyValue;
  46                 private AsnEncodedData _params;
  47                 private Oid _oid;
  48
  49                 public PublicKey (Oid oid, AsnEncodedData parameters, AsnEncodedData keyValue)
  50                 {
  51                         if (oid == null)
  52                                 throw new ArgumentNullException ("oid");
  53                         if (parameters == null)
  54                                 throw new ArgumentNullException ("parameters");
  55                         if (keyValue == null)
  56                                 throw new ArgumentNullException ("keyValue");
  57
  58                         _oid = new Oid (oid);
  59                         _params = new AsnEncodedData (parameters);
  60                         _keyValue = new AsnEncodedData (keyValue);
  61                 }
  62
  63                 internal PublicKey (MSX.X509Certificate certificate)
  64                 {
  65                         if (certificate.KeyAlgorithm == rsaOid) {
  66                                 _key = certificate.RSA;
  67                         } else {
  68                                 _key = certificate.DSA;
  69                         }
  70
  71                         _oid = new Oid (certificate.KeyAlgorithm);
  72                         _keyValue = new AsnEncodedData (_oid, certificate.PublicKey);
  73                         _params = new AsnEncodedData (_oid, certificate.KeyAlgorithmParameters);
  74                 }
  75
  76                 // properties
  77
  78                 public AsnEncodedData EncodedKeyValue {
  79                         get { return _keyValue; }
  80                 }
  81
  82                 public AsnEncodedData EncodedParameters {
  83                         get { return _params; }
  84                 }
  85
  86                 public AsymmetricAlgorithm Key {
  87                         get {
  88                                 if (_key == null) {
  89                                         switch (_oid.Value) {
  90                                         case rsaOid:
  91                                                 _key = DecodeRSA (_keyValue.RawData);
  92                                                 break;
  93                                         case dsaOid:
  94                                                 _key = DecodeDSA (_keyValue.RawData, _params.RawData);
  95                                                 break;
  96                                         default:
  97                                                 string msg = Locale.GetText ("Cannot decode public key from unknown OID '{0}'.", _oid.Value);
  98                                                 throw new NotSupportedException (msg);
  99                                         }
 100                                 }
 101                                 return _key;
 102                         }
 103                 }
 104
 105                 public Oid Oid {
 106                         get { return _oid; }
 107                 }
 108
 109                 // private stuff
 110
 111                 static private byte[] GetUnsignedBigInteger (byte[] integer)
 112                 {
 113                         if (integer [0] != 0x00)
 114                                 return integer;
 115
 116                         // this first byte is added so we're sure it's an unsigned integer
 117                         // however we can't feed it into RSAParameters or DSAParameters
 118                         int length = integer.Length - 1;
 119                         byte[] uinteger = new byte [length];
 120                         Buffer.BlockCopy (integer, 1, uinteger, 0, length);
 121                         return uinteger;
 122                 }
 123
 124                 static internal DSA DecodeDSA (byte[] rawPublicKey, byte[] rawParameters)
 125                 {
 126                         DSAParameters dsaParams = new DSAParameters ();
 127                         try {
 128                                 // for DSA rawPublicKey contains 1 ASN.1 integer - Y
 129                                 ASN1 pubkey = new ASN1 (rawPublicKey);
 130                                 if (pubkey.Tag != 0x02)
 131                                         throw new CryptographicException (Locale.GetText ("Missing DSA Y integer."));
 132                                 dsaParams.Y = GetUnsignedBigInteger (pubkey.Value);
 133
 134                                 ASN1 param = new ASN1 (rawParameters);
 135                                 if ((param == null) || (param.Tag != 0x30) || (param.Count < 3))
 136                                         throw new CryptographicException (Locale.GetText ("Missing DSA parameters."));
 137                                 if ((param [0].Tag != 0x02) || (param [1].Tag != 0x02) || (param [2].Tag != 0x02))
 138                                         throw new CryptographicException (Locale.GetText ("Invalid DSA parameters."));
 139
 140                                 dsaParams.P = GetUnsignedBigInteger (param [0].Value);
 141                                 dsaParams.Q = GetUnsignedBigInteger (param [1].Value);
 142                                 dsaParams.G = GetUnsignedBigInteger (param [2].Value);
 143                         }
 144                         catch (Exception e) {
 145                                 string msg = Locale.GetText ("Error decoding the ASN.1 structure.");
 146                                 throw new CryptographicException (msg, e);
 147                         }
 148
 149                         DSA dsa = (DSA) new DSACryptoServiceProvider (dsaParams.Y.Length << 3);
 150                         dsa.ImportParameters (dsaParams);
 151                         return dsa;
 152                 }
 153
 154                 static internal RSA DecodeRSA (byte[] rawPublicKey)
 155                 {
 156                         RSAParameters rsaParams = new RSAParameters ();
 157                         try {
 158                                 // for RSA rawPublicKey contains 2 ASN.1 integers
 159                                 // the modulus and the public exponent
 160                                 ASN1 pubkey = new ASN1 (rawPublicKey);
 161                                 if (pubkey.Count == 0)
 162                                         throw new CryptographicException (Locale.GetText ("Missing RSA modulus and exponent."));
 163                                 ASN1 modulus = pubkey [0];
 164                                 if ((modulus == null) || (modulus.Tag != 0x02))
 165                                         throw new CryptographicException (Locale.GetText ("Missing RSA modulus."));
 166                                 ASN1 exponent = pubkey [1];
 167                                 if (exponent.Tag != 0x02)
 168                                         throw new CryptographicException (Locale.GetText ("Missing RSA public exponent."));
 169
 170                                 rsaParams.Modulus = GetUnsignedBigInteger (modulus.Value);
 171                                 rsaParams.Exponent = exponent.Value;
 172                         }
 173                         catch (Exception e) {
 174                                 string msg = Locale.GetText ("Error decoding the ASN.1 structure.");
 175                                 throw new CryptographicException (msg, e);
 176                         }
 177
 178                         int keySize = (rsaParams.Modulus.Length << 3);
 179                         RSA rsa = (RSA) new RSACryptoServiceProvider (keySize);
 180                         rsa.ImportParameters (rsaParams);
 181                         return rsa;
 182                 }
 183         }
 184 }
 185
 186 #endif