mcs/class/corlib/System.Security.Cryptography/RSAPKCS1KeyExchangeFormatter.cs

   1 //
   2 // RSAPKCS1KeyExchangeFormatter.cs: Handles PKCS#1 v.1.5 keyex encryption.
   3 //
   4 // Author:
   5 //      Sebastien Pouliot (spouliot@motus.com)
   6 //
   7 // (C) 2002 Motus Technologies Inc. (http://www.motus.com)
   8 //
   9
  10 using System;
  11 using Mono.Security.Cryptography;
  12
  13 namespace System.Security.Cryptography {
  14
  15         // LAMESPEC: There seems no way to select a hash algorithm. The default
  16         // algorithm, is SHA1 because the class use the PKCS1MaskGenerationMethod -
  17         // which default to SHA1.
  18         public class RSAPKCS1KeyExchangeFormatter: AsymmetricKeyExchangeFormatter
  19         {
  20                 private RSA rsa;
  21                 private RandomNumberGenerator random;
  22
  23                 public RSAPKCS1KeyExchangeFormatter ()
  24                 {
  25                 }
  26
  27                 public RSAPKCS1KeyExchangeFormatter (AsymmetricAlgorithm key)
  28                 {
  29                         SetKey (key);
  30                 }
  31
  32                 public RandomNumberGenerator Rng
  33                 {
  34                         get { return random; }
  35                         set { random = value; }
  36                 }
  37
  38                 public override string Parameters
  39                 {
  40                         get { return "<enc:KeyEncryptionMethod enc:Algorithm=\"http://www.microsoft.com/xml/security/algorithm/PKCS1-v1.5-KeyEx\" xmlns:enc=\"http://www.microsoft.com/xml/security/encryption/v1.0\" />"; }
  41                 }
  42
  43                 public override byte[] CreateKeyExchange (byte[] rgbData)
  44                 {
  45                         if (rsa == null)
  46                                 throw new CryptographicException ();
  47                         if (random == null)
  48                                 random = RandomNumberGenerator.Create ();  // create default
  49                         return PKCS1.Encrypt_v15 (rsa, random, rgbData);
  50                 }
  51
  52                 public override byte[] CreateKeyExchange (byte[] rgbData, Type symAlgType)
  53                 {
  54                         // documentation says that symAlgType is not used !?!
  55                         // FIXME: must be the same as previous method ?
  56                         return CreateKeyExchange (rgbData);
  57                 }
  58
  59                 public override void SetKey (AsymmetricAlgorithm key)
  60                 {
  61                         if (key != null) {
  62                                 if (key is RSA) {
  63                                         rsa = (RSA)key;
  64                                 }
  65                                 else
  66                                         throw new InvalidCastException ();
  67                         }
  68                         // here null is accepted!
  69                 }
  70         }
  71 }