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

   1 //
   2 // TlsBuffer.cs
   3 //
   4 // Author:
   5 //       Martin Baulig <martin.baulig@xamarin.com>
   6 //
   7 // Copyright (c) 2014-2016 Xamarin Inc. (http://www.xamarin.com)
   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 using System;
  27
  28 namespace Mono.Security.Interface
  29 {
  30         public class TlsBuffer : SecretParameters
  31         {
  32                 public int Position {
  33                         get; set;
  34                 }
  35
  36                 public int Remaining {
  37                         get { return Size - (Position - Offset); }
  38                 }
  39
  40                 public byte[] Buffer {
  41                         get { return innerBuffer.Buffer; }
  42                 }
  43
  44                 public int Offset {
  45                         get { return innerBuffer.Offset; }
  46                 }
  47
  48                 public int Size {
  49                         get { return innerBuffer.Size; }
  50                 }
  51
  52                 public int EndOffset {
  53                         get { return Offset + Size; }
  54                 }
  55
  56                 IBufferOffsetSize innerBuffer;
  57
  58                 protected TlsBuffer ()
  59                         : this (null, 0, 0)
  60                 {
  61                 }
  62
  63                 public TlsBuffer (IBufferOffsetSize bos)
  64                 {
  65                         innerBuffer = bos;
  66                         Position = bos.Offset;
  67                 }
  68
  69                 public TlsBuffer (byte[] buffer, int offset, int size)
  70                         : this (new BufferOffsetSize (buffer, offset, size))
  71                 {
  72                 }
  73
  74                 public TlsBuffer (byte[] buffer)
  75                         : this (buffer, 0, buffer.Length)
  76                 {
  77                 }
  78
  79                 public TlsBuffer (int size)
  80                         : this (new byte [size], 0, size)
  81                 {
  82                 }
  83
  84                 public byte ReadByte ()
  85                 {
  86                         if (Position >= EndOffset)
  87                                 throw new TlsException (AlertDescription.DecodeError, "Buffer overflow");
  88                         return Buffer [Position++];
  89                 }
  90
  91                 public short ReadInt16 ()
  92                 {
  93                         if (Position + 1 >= EndOffset)
  94                                 throw new TlsException (AlertDescription.DecodeError, "Buffer overflow");
  95                         var retval = (short)(Buffer [Position] << 8 | Buffer [Position + 1]);
  96                         Position += 2;
  97                         return retval;
  98                 }
  99
 100                 public int ReadInt24 ()
 101                 {
 102                         if (Position + 2 >= EndOffset)
 103                                 throw new TlsException (AlertDescription.DecodeError, "Buffer overflow");
 104                         var retval = ((Buffer [Position] << 16) | (Buffer [Position+1] << 8) | Buffer [Position+2]);
 105                         Position += 3;
 106                         return retval;
 107                 }
 108
 109                 public int ReadInt32 ()
 110                 {
 111                         if (Position + 3 >= EndOffset)
 112                                 throw new TlsException (AlertDescription.DecodeError, "Buffer overflow");
 113                         var retval = ((Buffer [Position] << 24) | (Buffer [Position+1] << 16) | (Buffer [Position+2] << 8) | Buffer [Position+3]);
 114                         Position += 4;
 115                         return retval;
 116                 }
 117
 118                 public TlsBuffer ReadBuffer (int length)
 119                 {
 120                         if (Position + length > EndOffset)
 121                                 throw new TlsException (AlertDescription.DecodeError, "Buffer overflow");
 122                         var retval = new TlsBuffer (Buffer, Position, length);
 123                         Position += length;
 124                         return retval;
 125                 }
 126
 127                 public IBufferOffsetSize GetRemaining ()
 128                 {
 129                         return new BufferOffsetSize (Buffer, Position, Remaining);
 130                 }
 131
 132                 protected virtual void MakeRoomInternal (int size)
 133                 {
 134                         if (Position + size > EndOffset)
 135                                 throw new TlsException (AlertDescription.DecodeError, "Buffer overflow");
 136                 }
 137
 138                 public void Write (byte value)
 139                 {
 140                         MakeRoomInternal (1);
 141                         Buffer [Position++] = value;
 142                 }
 143
 144                 public void Write (short value)
 145                 {
 146                         MakeRoomInternal (2);
 147                         WriteInt16 (Buffer, Position, value);
 148                         Position += 2;
 149                 }
 150
 151                 public static void WriteInt16 (byte[] buffer, int offset, short value)
 152                 {
 153                         buffer[offset] = ((byte)(value >> 8));
 154                         buffer[offset+1] = ((byte)value);
 155                 }
 156
 157                 public void Write (int value)
 158                 {
 159                         MakeRoomInternal (4);
 160                         WriteInt32 (Buffer, Position, value);
 161                         Position += 4;
 162                 }
 163
 164                 public void WriteInt24 (int value)
 165                 {
 166                         MakeRoomInternal (3);
 167                         WriteInt24 (Buffer, Position, value);
 168                         Position += 3;
 169                 }
 170
 171                 #pragma warning disable 3001
 172                 public void Write (ulong value)
 173                 #pragma warning restore 3001
 174                 {
 175                         MakeRoomInternal (8);
 176                         WriteInt64 (Buffer, Position, value);
 177                         Position += 8;
 178                 }
 179
 180                 public static void WriteInt24 (byte[] buffer, int offset, int value)
 181                 {
 182                         buffer[offset] = ((byte)(value >> 16));
 183                         buffer[offset+1] = ((byte)(value >> 8));
 184                         buffer[offset+2] = ((byte)value);
 185                 }
 186
 187                 public static void WriteInt32 (byte[] buffer, int offset, int value)
 188                 {
 189                         buffer[offset] = ((byte)(value >> 24));
 190                         buffer[offset+1] = ((byte)(value >> 16));
 191                         buffer[offset+2] = ((byte)(value >> 8));
 192                         buffer[offset+3] = ((byte)value);
 193                 }
 194
 195                 #pragma warning disable 3001
 196                 public static void WriteInt64 (byte[] buffer, int offset, ulong value)
 197                 #pragma warning restore 3001
 198                 {
 199                         buffer[offset] = (byte) (value >> 56);
 200                         buffer[offset+1] = (byte) (value >> 48);
 201                         buffer[offset+2] = (byte) (value >> 40);
 202                         buffer[offset+3] = (byte) (value >> 32);
 203                         buffer[offset+4] = (byte) (value >> 24);
 204                         buffer[offset+5] = (byte) (value >> 16);
 205                         buffer[offset+6] = (byte) (value >> 8);
 206                         buffer[offset+7] = (byte) value;
 207                 }
 208
 209                 public void Write (byte[] buffer)
 210                 {
 211                         Write (buffer, 0, buffer.Length);
 212                 }
 213
 214                 public void Write (byte[] buffer, int offset, int size)
 215                 {
 216                         MakeRoomInternal (size);
 217                         Array.Copy (buffer, offset, Buffer, Position, size);
 218                         Position += size;
 219                 }
 220
 221                 public void Write (IBufferOffsetSize buffer)
 222                 {
 223                         Write (buffer.Buffer, buffer.Offset, buffer.Size);
 224                 }
 225
 226                 public SecureBuffer ReadSecureBuffer (int count)
 227                 {
 228                         return new SecureBuffer (ReadBytes (count));
 229                 }
 230
 231                 public byte[] ReadBytes (int count)
 232                 {
 233                         if (Position + count > EndOffset)
 234                                 throw new TlsException (AlertDescription.DecodeError, "Buffer overflow");
 235                         var retval = new byte [count];
 236                         Array.Copy (Buffer, Position, retval, 0, count);
 237                         Position += count;
 238                         return retval;
 239                 }
 240
 241                 internal static bool Compare (SecureBuffer buffer1, SecureBuffer buffer2)
 242                 {
 243                         if (buffer1 == null || buffer2 == null)
 244                                 return false;
 245
 246                         if (buffer1.Size != buffer2.Size)
 247                                 return false;
 248
 249                         for (int i = 0; i < buffer1.Size; i++) {
 250                                 if (buffer1.Buffer [i] != buffer2.Buffer [i])
 251                                         return false;
 252                         }
 253                         return true;
 254                 }
 255
 256                 public static bool Compare (IBufferOffsetSize buffer1, IBufferOffsetSize buffer2)
 257                 {
 258                         if (buffer1 == null || buffer2 == null)
 259                                 return false;
 260
 261                         if (buffer1.Size != buffer2.Size)
 262                                 return false;
 263
 264                         for (int i = 0; i < buffer1.Size; i++) {
 265                                 if (buffer1.Buffer [buffer1.Offset + i] != buffer2.Buffer [buffer2.Offset + i])
 266                                         return false;
 267                         }
 268                         return true;
 269                 }
 270
 271                 public static bool Compare (byte[] buffer1, byte[] buffer2)
 272                 {
 273                         if (buffer1 == null || buffer2 == null)
 274                                 return false;
 275
 276                         return Compare (buffer1, 0, buffer1.Length, buffer2, 0, buffer2.Length);
 277                 }
 278
 279                 public static bool Compare (byte[] buffer1, int offset1, int size1, byte[] buffer2, int offset2, int size2)
 280                 {
 281                         if (buffer1 == null || buffer2 == null)
 282                                 return false;
 283
 284                         if (size1 != size2)
 285                                 return false;
 286
 287                         for (int i = 0; i < size1; i++) {
 288                                 if (buffer1 [offset1 + i] != buffer2 [offset2 + i])
 289                                         return false;
 290                         }
 291                         return true;
 292
 293                 }
 294
 295                 public static int ConstantTimeCompare (byte[] buffer1, int offset1, int size1, byte[] buffer2, int offset2, int size2)
 296                 {
 297                         int status = 0;
 298                         int effectiveSize;
 299                         if (size1 < size2) {
 300                                 status--;
 301                                 effectiveSize = size1;
 302                         } else if (size2 < size1) {
 303                                 status--;
 304                                 effectiveSize = size2;
 305                         } else {
 306                                 effectiveSize = size1;
 307                         }
 308
 309                         for (int i = 0; i < effectiveSize; i++) {
 310                                 if (buffer1 [offset1 + i] != buffer2 [offset2 + i])
 311                                         status--;
 312                         }
 313
 314                         return status;
 315                 }
 316
 317                 protected void SetBuffer (byte[] buffer, int offset, int size)
 318                 {
 319                         innerBuffer = new BufferOffsetSize (buffer, offset, size);
 320                 }
 321
 322                 protected override void Clear ()
 323                 {
 324                         var disposable = innerBuffer as IDisposable;
 325                         if (disposable != null)
 326                                 disposable.Dispose ();
 327                         innerBuffer = null;
 328                         Position = 0;
 329                 }
 330
 331                 public static readonly byte[] EmptyArray = new byte [0];
 332         }
 333 }
 334