class/Novell.Directory.Ldap/Novell.Directory.Ldap.Security.jvm/SecureStream.cs

   1 //
   2 // Novell.Directory.Ldap.Security.SecureStream.cs
   3 //
   4 // Authors:
   5 //  Boris Kirzner <borsk@mainsoft.com>
   6 //      Konstantin Triger <kostat@mainsoft.com>
   7 //
   8 // (C) 2005 Mainsoft Corporation (http://www.mainsoft.com)
   9 //
  10
  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 using System;
  33 using System.IO;
  34
  35 namespace Novell.Directory.Ldap.Security
  36 {
  37         internal class SecureStream : Stream
  38         {
  39                 #region Fields
  40
  41                 private readonly Stream _stream;
  42                 private readonly Krb5Helper _helper;
  43
  44                 private readonly byte [] _lenBuf = new byte [4];
  45                 private byte [] _buffer;
  46                 private int _bufferPosition;
  47
  48                 #endregion // Fields
  49
  50                 #region Constructors
  51
  52                 public SecureStream(Stream stream, Krb5Helper helper): base ()
  53                 {
  54                         _stream = stream;
  55                         _helper = helper;
  56                 }
  57
  58                 #endregion // Constructors
  59
  60                 #region Properties
  61
  62                 public override bool CanRead
  63                 {
  64                         get { return _stream.CanRead; }
  65                 }
  66
  67                 public override bool CanSeek
  68                 {
  69                         get { return _stream.CanSeek; }
  70                 }
  71
  72                 public override bool CanWrite
  73                 {
  74                         get { return _stream.CanWrite; }
  75                 }
  76
  77                 public override long Length
  78                 {
  79                         get { throw new NotSupportedException (); }
  80                 }
  81
  82                 public override long Position
  83                 {
  84                         get { throw new NotSupportedException (); }
  85                         set { throw new NotSupportedException (); }
  86                 }
  87
  88                 #endregion // Properties
  89
  90                 #region Methods
  91
  92                 public override void Flush()
  93                 {
  94                         _stream.Flush ();
  95                 }
  96
  97                 public override int Read( byte [] buffer, int offset, int count)
  98                 {
  99                         if (_buffer == null || _bufferPosition >= _buffer.Length) {
 100                                 int actual = Fill ();
 101                                 while (actual == 0)
 102                                         actual = Fill ();
 103
 104                                 if (actual == -1)
 105                                         return -1;
 106                         }
 107
 108                         int available = _buffer.Length - _bufferPosition;
 109                         if (count > available) {
 110                                 Array.Copy (_buffer, _bufferPosition, buffer, offset, available);
 111                                 _bufferPosition = _buffer.Length;
 112                                 return available;
 113                         }
 114                         else {
 115                                 Array.Copy (_buffer, _bufferPosition, buffer, offset, count);
 116                                 _bufferPosition += count;
 117                                 return count;
 118                         }
 119                 }
 120
 121                 public override void Close() {
 122                         _stream.Close();
 123                         _helper.Dispose();
 124                 }
 125
 126                 private int Fill()
 127                 {
 128                         int actual = ReadAll (_lenBuf, 4);
 129
 130                         if (actual != 4)
 131                                 return -1;
 132
 133                         int length = NetworkByteOrderToInt (_lenBuf, 0, 4);
 134
 135 //                      if (length > _recvMaxBufSize)
 136 //                              throw new LdapException(length + " exceeds the negotiated receive buffer size limit: " + _recvMaxBufSize, 80, "");
 137
 138                         byte [] rawBuffer = new byte [length];
 139                         actual = ReadAll (rawBuffer, length);
 140
 141                         if (actual != length)
 142                                 throw new LdapException("Expected to read " + length + " bytes, but get " + actual, 80, "");
 143
 144                         _buffer = _helper.Unwrap (rawBuffer, 0, length);
 145                         _bufferPosition = 0;
 146                         return _buffer.Length;
 147                 }
 148
 149                 private int ReadAll(byte [] buffer, int total)
 150                 {
 151                         int count = 0;
 152                         int pos = 0;
 153                         while (total > 0) {
 154                                 count = _stream.Read (buffer, pos, total);
 155
 156                                 if (count == -1)
 157                                         break;
 158                                         //return ((pos == 0) ? -1 : pos);
 159
 160                                 pos += count;
 161                                 total -= count;
 162                         }
 163                         return pos;
 164                 }
 165
 166                 public override long Seek(long offset, SeekOrigin loc)
 167                 {
 168                         return _stream.Seek (offset, loc);
 169                 }
 170
 171                 public override void SetLength(long value)
 172                 {
 173                         _stream.SetLength (value);
 174                 }
 175
 176                 public override void Write(byte [] buffer, int offset, int count)
 177                 {
 178                         // FIXME: use GSSCOntext.getWrapSizeLimit to divide the buffer
 179                         // Generate wrapped token
 180                         byte [] wrappedToken = _helper.Wrap (buffer, offset, count);
 181                         // Write out length
 182                         IntToNetworkByteOrder (wrappedToken.Length, _lenBuf, 0, 4);
 183                         _stream.Write (_lenBuf, 0, 4);
 184                         // Write out wrapped token
 185                         _stream.Write (wrappedToken, 0, wrappedToken.Length);
 186                 }
 187
 188                 internal static int NetworkByteOrderToInt(byte [] buf, int start, int count)
 189                 {
 190                         int answer = 0;
 191                         for (int i = 0; i < count; i++) {
 192                                 answer <<= 8;
 193                                 answer |= ((int)buf [start + i] & 0xff);
 194                         }
 195                         return answer;
 196                 }
 197
 198                 internal static void IntToNetworkByteOrder(int num, byte [] buf, int start, int count)
 199                 {
 200                         for (int i = count-1; i >= 0; i--) {
 201                                 buf [start + i] = (byte)(num & 0xff);
 202                                 num >>= 8;
 203                         }
 204                 }
 205
 206                 #endregion // Methods
 207         }
 208 }