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 SECURITY_DEP
  33
  34 #if MONOTOUCH
  35 using Mono.Security;
  36 using Mono.Security.Cryptography;
  37 using MSX = Mono.Security.X509;
  38 #else
  39 extern alias MonoSecurity;
  40 using MonoSecurity::Mono.Security;
  41 using MonoSecurity::Mono.Security.Cryptography;
  42 using MSX = MonoSecurity::Mono.Security.X509;
  43 #endif
  44
  45 namespace System.Security.Cryptography.X509Certificates {
  46
  47         public sealed class PublicKey {
  48
  49                 private const string rsaOid = "1.2.840.113549.1.1.1";
  50                 private const string dsaOid = "1.2.840.10040.4.1";
  51
  52                 private AsymmetricAlgorithm _key;
  53                 private AsnEncodedData _keyValue;
  54                 private AsnEncodedData _params;
  55                 private Oid _oid;
  56
  57                 static byte[] Empty = new byte [0];
  58
  59                 public PublicKey (Oid oid, AsnEncodedData parameters, AsnEncodedData keyValue)
  60                 {
  61                         if (oid == null)
  62                                 throw new ArgumentNullException ("oid");
  63                         if (parameters == null)
  64                                 throw new ArgumentNullException ("parameters");
  65                         if (keyValue == null)
  66                                 throw new ArgumentNullException ("keyValue");
  67
  68                         _oid = new Oid (oid);
  69                         _params = new AsnEncodedData (parameters);
  70                         _keyValue = new AsnEncodedData (keyValue);
  71                 }
  72
  73                 internal PublicKey (MSX.X509Certificate certificate)
  74                 {
  75                         // note: _key MUSTonly contains the public part of the key
  76                         bool export_required = true;
  77
  78                         if (certificate.KeyAlgorithm == rsaOid) {
  79                                 // shortcut export/import in the case the private key isn't available
  80                                 RSACryptoServiceProvider rcsp = (certificate.RSA as RSACryptoServiceProvider);
  81                                 if ((rcsp != null) && rcsp.PublicOnly) {
  82                                         _key = certificate.RSA;
  83                                         export_required = false;
  84                                 } else
  85                                 {
  86                                         RSAManaged rsam = (certificate.RSA as RSAManaged);
  87                                         if ((rsam != null) && rsam.PublicOnly) {
  88                                                 _key = certificate.RSA;
  89                                                 export_required = false;
  90                                         }
  91                                 }
  92
  93                                 if (export_required) {
  94                                         RSAParameters rsap = certificate.RSA.ExportParameters (false);
  95                                         _key = RSA.Create ();
  96                                         (_key as RSA).ImportParameters (rsap);
  97                                 }
  98                         } else {
  99                                 // shortcut export/import in the case the private key isn't available
 100                                 DSACryptoServiceProvider dcsp = (certificate.DSA as DSACryptoServiceProvider);
 101                                 if ((dcsp != null) && dcsp.PublicOnly) {
 102                                         _key = certificate.DSA;
 103                                         export_required = false;
 104                                 }
 105                                 // note: DSAManaged isn't available in Mono.Security due to a bug in Fx 1.x
 106
 107                                 if (export_required) {
 108                                         DSAParameters rsap = certificate.DSA.ExportParameters (false);
 109                                         _key = DSA.Create ();
 110                                         (_key as DSA).ImportParameters (rsap);
 111                                 }
 112                         }
 113
 114                         _oid = new Oid (certificate.KeyAlgorithm);
 115                         _keyValue = new AsnEncodedData (_oid, certificate.PublicKey);
 116                         _params = new AsnEncodedData (_oid, certificate.KeyAlgorithmParameters ?? Empty);
 117                 }
 118
 119                 // properties
 120
 121                 public AsnEncodedData EncodedKeyValue {
 122                         get { return _keyValue; }
 123                 }
 124
 125                 public AsnEncodedData EncodedParameters {
 126                         get { return _params; }
 127                 }
 128
 129                 public AsymmetricAlgorithm Key {
 130                         get {
 131                                 if (_key == null) {
 132                                         switch (_oid.Value) {
 133                                         case rsaOid:
 134                                                 _key = DecodeRSA (_keyValue.RawData);
 135                                                 break;
 136                                         case dsaOid:
 137                                                 _key = DecodeDSA (_keyValue.RawData, _params.RawData);
 138                                                 break;
 139                                         default:
 140                                                 string msg = Locale.GetText ("Cannot decode public key from unknown OID '{0}'.", _oid.Value);
 141                                                 throw new NotSupportedException (msg);
 142                                         }
 143                                 }
 144                                 return _key;
 145                         }
 146                 }
 147
 148                 public Oid Oid {
 149                         get { return _oid; }
 150                 }
 151
 152                 // private stuff
 153
 154                 static private byte[] GetUnsignedBigInteger (byte[] integer)
 155                 {
 156                         if (integer [0] != 0x00)
 157                                 return integer;
 158
 159                         // this first byte is added so we're sure it's an unsigned integer
 160                         // however we can't feed it into RSAParameters or DSAParameters
 161                         int length = integer.Length - 1;
 162                         byte[] uinteger = new byte [length];
 163                         Buffer.BlockCopy (integer, 1, uinteger, 0, length);
 164                         return uinteger;
 165                 }
 166
 167                 static internal DSA DecodeDSA (byte[] rawPublicKey, byte[] rawParameters)
 168                 {
 169                         DSAParameters dsaParams = new DSAParameters ();
 170                         try {
 171                                 // for DSA rawPublicKey contains 1 ASN.1 integer - Y
 172                                 ASN1 pubkey = new ASN1 (rawPublicKey);
 173                                 if (pubkey.Tag != 0x02)
 174                                         throw new CryptographicException (Locale.GetText ("Missing DSA Y integer."));
 175                                 dsaParams.Y = GetUnsignedBigInteger (pubkey.Value);
 176
 177                                 ASN1 param = new ASN1 (rawParameters);
 178                                 if ((param == null) || (param.Tag != 0x30) || (param.Count < 3))
 179                                         throw new CryptographicException (Locale.GetText ("Missing DSA parameters."));
 180                                 if ((param [0].Tag != 0x02) || (param [1].Tag != 0x02) || (param [2].Tag != 0x02))
 181                                         throw new CryptographicException (Locale.GetText ("Invalid DSA parameters."));
 182
 183                                 dsaParams.P = GetUnsignedBigInteger (param [0].Value);
 184                                 dsaParams.Q = GetUnsignedBigInteger (param [1].Value);
 185                                 dsaParams.G = GetUnsignedBigInteger (param [2].Value);
 186                         }
 187                         catch (Exception e) {
 188                                 string msg = Locale.GetText ("Error decoding the ASN.1 structure.");
 189                                 throw new CryptographicException (msg, e);
 190                         }
 191
 192                         DSA dsa = (DSA) new DSACryptoServiceProvider (dsaParams.Y.Length << 3);
 193                         dsa.ImportParameters (dsaParams);
 194                         return dsa;
 195                 }
 196
 197                 static internal RSA DecodeRSA (byte[] rawPublicKey)
 198                 {
 199                         RSAParameters rsaParams = new RSAParameters ();
 200                         try {
 201                                 // for RSA rawPublicKey contains 2 ASN.1 integers
 202                                 // the modulus and the public exponent
 203                                 ASN1 pubkey = new ASN1 (rawPublicKey);
 204                                 if (pubkey.Count == 0)
 205                                         throw new CryptographicException (Locale.GetText ("Missing RSA modulus and exponent."));
 206                                 ASN1 modulus = pubkey [0];
 207                                 if ((modulus == null) || (modulus.Tag != 0x02))
 208                                         throw new CryptographicException (Locale.GetText ("Missing RSA modulus."));
 209                                 ASN1 exponent = pubkey [1];
 210                                 if (exponent.Tag != 0x02)
 211                                         throw new CryptographicException (Locale.GetText ("Missing RSA public exponent."));
 212
 213                                 rsaParams.Modulus = GetUnsignedBigInteger (modulus.Value);
 214                                 rsaParams.Exponent = exponent.Value;
 215                         }
 216                         catch (Exception e) {
 217                                 string msg = Locale.GetText ("Error decoding the ASN.1 structure.");
 218                                 throw new CryptographicException (msg, e);
 219                         }
 220
 221                         int keySize = (rsaParams.Modulus.Length << 3);
 222                         RSA rsa = (RSA) new RSACryptoServiceProvider (keySize);
 223                         rsa.ImportParameters (rsaParams);
 224                         return rsa;
 225                 }
 226         }
 227 }
 228
 229 #endif