mcs/class/Mono.Security/Mono.Security.Interface/Alert.cs

   1 //
   2 // Alert.cs
   3 //
   4 // Author:
   5 //       Martin Baulig <martin.baulig@xamarin.com>
   6 //
   7 // Copyright (c) 2015 Xamarin, Inc.
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining a copy
  10 // of this software and associated documentation files (the "Software"), to deal
  11 // in the Software without restriction, including without limitation the rights
  12 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13 // copies of the Software, and to permit persons to whom the Software is
  14 // furnished to do so, subject to the following conditions:
  15 //
  16 // The above copyright notice and this permission notice shall be included in
  17 // all copies or substantial portions of the Software.
  18 //
  19 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25 // THE SOFTWARE.
  26
  27 using System;
  28
  29 namespace Mono.Security.Interface
  30 {
  31         #region Enumerations
  32
  33         public enum AlertLevel : byte
  34         {
  35                 Warning = 1,
  36                 Fatal   = 2
  37         }
  38
  39         public enum AlertDescription : byte
  40         {
  41                 CloseNotify                     = 0,
  42                 UnexpectedMessage               = 10,
  43                 BadRecordMAC                    = 20,
  44                 DecryptionFailed_RESERVED       = 21,
  45                 RecordOverflow                  = 22,
  46                 DecompressionFailure            = 30,
  47                 HandshakeFailure                = 40,
  48                 NoCertificate_RESERVED          = 41,   // should be used in SSL3
  49                 BadCertificate                  = 42,
  50                 UnsupportedCertificate          = 43,
  51                 CertificateRevoked              = 44,
  52                 CertificateExpired              = 45,
  53                 CertificateUnknown              = 46,
  54                 IlegalParameter                 = 47,
  55                 UnknownCA                       = 48,
  56                 AccessDenied                    = 49,
  57                 DecodeError                     = 50,
  58                 DecryptError                    = 51,
  59                 ExportRestriction               = 60,
  60                 ProtocolVersion                 = 70,
  61                 InsuficientSecurity             = 71,
  62                 InternalError                   = 80,
  63                 UserCancelled                   = 90,
  64                 NoRenegotiation                 = 100,
  65                 UnsupportedExtension            = 110
  66         }
  67
  68         #endregion
  69
  70         public class Alert
  71         {
  72                 #region Fields
  73
  74                 private AlertLevel                      level;
  75                 private AlertDescription        description;
  76
  77                 #endregion
  78
  79                 #region Properties
  80
  81                 public AlertLevel Level
  82                 {
  83                         get { return this.level; }
  84                 }
  85
  86                 public AlertDescription Description
  87                 {
  88                         get { return this.description; }
  89                 }
  90
  91                 public string Message
  92                 {
  93                         get { return Alert.GetAlertMessage(this.description); }
  94                 }
  95
  96                 public bool IsWarning
  97                 {
  98                         get { return this.level == AlertLevel.Warning ? true : false; }
  99                 }
 100
 101                 /*
 102                 public bool IsFatal
 103                 {
 104                         get { return this.level == AlertLevel.Fatal ? true : false; }
 105                 }
 106                 */
 107
 108                 public bool IsCloseNotify
 109                 {
 110                         get
 111                         {
 112                                 if (this.IsWarning &&
 113                                         this.description == AlertDescription.CloseNotify)
 114                                 {
 115                                         return true;
 116                                 }
 117
 118                                 return false;
 119                         }
 120                 }
 121
 122                 #endregion
 123
 124                 #region Constructors
 125
 126                 public Alert(AlertDescription description)
 127                 {
 128                         this.description = description;
 129                         this.inferAlertLevel();
 130                 }
 131
 132                 public Alert(
 133                         AlertLevel                      level,
 134                         AlertDescription        description)
 135                 {
 136                         this.level                      = level;
 137                         this.description        = description;
 138                 }
 139
 140                 #endregion
 141
 142                 #region Private Methods
 143
 144                 private void inferAlertLevel()
 145                 {
 146                         switch (description)
 147                         {
 148                                 case AlertDescription.CloseNotify:
 149                                 case AlertDescription.NoRenegotiation:
 150                                 case AlertDescription.UserCancelled:
 151                                         this.level = AlertLevel.Warning;
 152                                         break;
 153
 154                                 case AlertDescription.AccessDenied:
 155                                 case AlertDescription.BadCertificate:
 156                                 case AlertDescription.BadRecordMAC:
 157                                 case AlertDescription.CertificateExpired:
 158                                 case AlertDescription.CertificateRevoked:
 159                                 case AlertDescription.CertificateUnknown:
 160                                 case AlertDescription.DecodeError:
 161                                 case AlertDescription.DecompressionFailure:
 162                                 case AlertDescription.DecryptError:
 163                                 case AlertDescription.DecryptionFailed_RESERVED:
 164                                 case AlertDescription.ExportRestriction:
 165                                 case AlertDescription.HandshakeFailure:
 166                                 case AlertDescription.IlegalParameter:
 167                                 case AlertDescription.InsuficientSecurity:
 168                                 case AlertDescription.InternalError:
 169                                 case AlertDescription.ProtocolVersion:
 170                                 case AlertDescription.RecordOverflow:
 171                                 case AlertDescription.UnexpectedMessage:
 172                                 case AlertDescription.UnknownCA:
 173                                 case AlertDescription.UnsupportedCertificate:
 174                                 case AlertDescription.UnsupportedExtension:
 175                                 default:
 176                                         this.level = AlertLevel.Fatal;
 177                                         break;
 178                         }
 179                 }
 180
 181                 #endregion
 182
 183                 public override string ToString ()
 184                 {
 185                         return string.Format ("[Alert: {0}:{1}]", Level, Description);
 186                 }
 187
 188                 #region Static Methods
 189
 190                 public static string GetAlertMessage(AlertDescription description)
 191                 {
 192                         #if (DEBUG)
 193                         switch (description)
 194                         {
 195                                 case AlertDescription.AccessDenied:
 196                                         return "An inappropriate message was received.";
 197
 198                                 case AlertDescription.BadCertificate:
 199                                         return "TLSCiphertext decrypted in an invalid way.";
 200
 201                                 case AlertDescription.BadRecordMAC:
 202                                         return "Record with an incorrect MAC.";
 203
 204                                 case AlertDescription.CertificateExpired:
 205                                         return "Certificate has expired or is not currently valid";
 206
 207                                 case AlertDescription.CertificateRevoked:
 208                                         return "Certificate was revoked by its signer.";
 209
 210                                 case AlertDescription.CertificateUnknown:
 211                                         return "Certificate Unknown.";
 212
 213                                 case AlertDescription.CloseNotify:
 214                                         return "Connection closed";
 215
 216                                 case AlertDescription.DecodeError:
 217                                         return "A message could not be decoded because some field was out of the specified range or the length of the message was incorrect.";
 218
 219                                 case AlertDescription.DecompressionFailure:
 220                                         return "The decompression function received improper input (e.g. data that would expand to excessive length).";
 221
 222                                 case AlertDescription.DecryptError:
 223                                         return "TLSCiphertext decrypted in an invalid way: either it wasn`t an even multiple of the block length or its padding values, when checked, weren`t correct.";
 224
 225                                 case AlertDescription.DecryptionFailed_RESERVED:
 226                                         return "Handshake cryptographic operation failed, including being unable to correctly verify a signature, decrypt a key exchange, or validate finished message.";
 227
 228                                 case AlertDescription.ExportRestriction:
 229                                         return "Negotiation not in compliance with export restrictions was detected.";
 230
 231                                 case AlertDescription.HandshakeFailure:
 232                                         return "Unable to negotiate an acceptable set of security parameters given the options available.";
 233
 234                                 case AlertDescription.IlegalParameter:
 235                                         return "A field in the handshake was out of range or inconsistent with other fields.";
 236
 237                                 case AlertDescription.InsuficientSecurity:
 238                                         return "Negotiation has failed specifically because the server requires ciphers more secure than those supported by the client.";
 239
 240                                 case AlertDescription.InternalError:
 241                                         return "Internal error unrelated to the peer or the correctness of the protocol makes it impossible to continue.";
 242
 243                                 case AlertDescription.NoRenegotiation:
 244                                         return "Invalid renegotiation.";
 245
 246                                 case AlertDescription.ProtocolVersion:
 247                                         return "Unsupported protocol version.";
 248
 249                                 case AlertDescription.RecordOverflow:
 250                                         return "Invalid length on TLSCiphertext record or TLSCompressed record.";
 251
 252                                 case AlertDescription.UnexpectedMessage:
 253                                         return "Invalid message received.";
 254
 255                                 case AlertDescription.UnknownCA:
 256                                         return "CA can't be identified as a trusted CA.";
 257
 258                                 case AlertDescription.UnsupportedCertificate:
 259                                         return "Certificate was of an unsupported type.";
 260
 261                                 case AlertDescription.UserCancelled:
 262                                         return "Handshake cancelled by user.";
 263
 264                                 case AlertDescription.UnsupportedExtension:
 265                                         return "Unsupported extension.";
 266
 267                                 default:
 268                                         return "";
 269                         }
 270                         #else
 271                         return "The authentication or decryption has failed.";
 272                         #endif
 273                 }
 274
 275                 #endregion
 276         }
 277 }