New: Implemented Torrent Download Clients: uTorrent, Transmission and Deluge. And several public and private Torrent Indexers.

src/MonoTorrent/BEncoding/BEncodedDictionary.cs

@@ -0,0 +1,321 @@
+using System;
+using System.IO;
+using System.Collections.Generic;
+using System.Text;
+
+namespace MonoTorrent.BEncoding
+{
+    /// <summary>
+    /// Class representing a BEncoded Dictionary
+    /// </summary>
+    public class BEncodedDictionary : BEncodedValue, IDictionary<BEncodedString, BEncodedValue>
+    {
+        #region Member Variables
+
+        private SortedDictionary<BEncodedString, BEncodedValue> dictionary;
+
+        #endregion
+
+
+        #region Constructors
+
+        /// <summary>
+        /// Create a new BEncodedDictionary
+        /// </summary>
+        public BEncodedDictionary()
+        {
+            this.dictionary = new SortedDictionary<BEncodedString, BEncodedValue>();
+        }
+
+        #endregion
+
+
+        #region Encode/Decode Methods
+
+        /// <summary>
+        /// Encodes the dictionary to a byte[]
+        /// </summary>
+        /// <param name="buffer">The buffer to encode the data to</param>
+        /// <param name="offset">The offset to start writing the data to</param>
+        /// <returns></returns>
+        public override int Encode(byte[] buffer, int offset)
+        {
+            int written = 0;
+
+            //Dictionaries start with 'd'
+            buffer[offset] = (byte)'d';
+            written++;
+
+            foreach (KeyValuePair<BEncodedString, BEncodedValue> keypair in this)
+            {
+                written += keypair.Key.Encode(buffer, offset + written);
+                written += keypair.Value.Encode(buffer, offset + written);
+            }
+
+            // Dictionaries end with 'e'
+            buffer[offset + written] = (byte)'e';
+            written++;
+            return written;
+        }
+
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="reader"></param>
+        internal override void DecodeInternal(RawReader reader)
+        {
+            DecodeInternal(reader, reader.StrictDecoding);
+        }
+
+        private void DecodeInternal(RawReader reader, bool strictDecoding)
+        {
+            BEncodedString key = null;
+            BEncodedValue value = null;
+            BEncodedString oldkey = null;
+
+            if (reader.ReadByte() != 'd')
+                throw new BEncodingException("Invalid data found. Aborting"); // Remove the leading 'd'
+
+            while ((reader.PeekByte() != -1) && (reader.PeekByte() != 'e'))
+            {
+                key = (BEncodedString)BEncodedValue.Decode(reader);         // keys have to be BEncoded strings
+
+                if (oldkey != null && oldkey.CompareTo(key) > 0)
+                    if (strictDecoding)
+                        throw new BEncodingException(String.Format(
+                            "Illegal BEncodedDictionary. The attributes are not ordered correctly. Old key: {0}, New key: {1}",
+                            oldkey, key));
+
+                oldkey = key;
+                value = BEncodedValue.Decode(reader);                     // the value is a BEncoded value
+                dictionary.Add(key, value);
+            }
+
+            if (reader.ReadByte() != 'e')                                    // remove the trailing 'e'
+                throw new BEncodingException("Invalid data found. Aborting");
+        }
+
+        public static BEncodedDictionary DecodeTorrent(byte[] bytes)
+        {
+            return DecodeTorrent(new MemoryStream(bytes));
+        }
+
+        public static BEncodedDictionary DecodeTorrent(Stream s)
+        {
+            return DecodeTorrent(new RawReader(s));
+        }
+
+
+        /// <summary>
+        /// Special decoding method for torrent files - allows dictionary attributes to be out of order for the
+        /// overall torrent file, but imposes strict rules on the info dictionary.
+        /// </summary>
+        /// <returns></returns>
+        public static BEncodedDictionary DecodeTorrent(RawReader reader)
+        {
+            BEncodedString key = null;
+            BEncodedValue value = null;
+            BEncodedDictionary torrent = new BEncodedDictionary();
+            if (reader.ReadByte() != 'd')
+                throw new BEncodingException("Invalid data found. Aborting"); // Remove the leading 'd'
+
+            while ((reader.PeekByte() != -1) && (reader.PeekByte() != 'e'))
+            {
+                key = (BEncodedString)BEncodedValue.Decode(reader);         // keys have to be BEncoded strings
+
+                if (reader.PeekByte() == 'd')
+                {
+                    value = new BEncodedDictionary();
+                    if (key.Text.ToLower().Equals("info"))
+                        ((BEncodedDictionary)value).DecodeInternal(reader, true);
+                    else
+                        ((BEncodedDictionary)value).DecodeInternal(reader, false);
+                }
+                else
+                    value = BEncodedValue.Decode(reader);                     // the value is a BEncoded value
+                    
+                torrent.dictionary.Add(key, value);
+            }
+
+            if (reader.ReadByte() != 'e')                                    // remove the trailing 'e'
+                throw new BEncodingException("Invalid data found. Aborting");
+
+            return torrent;
+        }
+
+        #endregion
+
+
+        #region Helper Methods
+
+        /// <summary>
+        /// Returns the size of the dictionary in bytes using UTF8 encoding
+        /// </summary>
+        /// <returns></returns>
+        public override int LengthInBytes()
+        {
+            int length = 0;
+            length += 1;   // Dictionaries start with 'd'
+
+            foreach (KeyValuePair<BEncodedString, BEncodedValue> keypair in this.dictionary)
+            {
+                length += keypair.Key.LengthInBytes();
+                length += keypair.Value.LengthInBytes();
+            }
+            length += 1;   // Dictionaries end with 'e'
+            return length;
+        }
+
+        #endregion
+
+
+        #region Overridden Methods
+        public override bool Equals(object obj)
+        {
+            BEncodedValue val;
+            BEncodedDictionary other = obj as BEncodedDictionary;
+            if (other == null)
+                return false;
+
+            if (this.dictionary.Count != other.dictionary.Count)
+                return false;
+
+            foreach (KeyValuePair<BEncodedString, BEncodedValue> keypair in this.dictionary)
+            {
+                if (!other.TryGetValue(keypair.Key, out val))
+                    return false;
+
+                if (!keypair.Value.Equals(val))
+                    return false;
+            }
+
+            return true;
+        }
+
+        public override int GetHashCode()
+        {
+            int result = 0;
+            foreach (KeyValuePair<BEncodedString, BEncodedValue> keypair in dictionary)
+            {
+                result ^= keypair.Key.GetHashCode();
+                result ^= keypair.Value.GetHashCode();
+            }
+
+            return result;
+        }
+
+        public override string ToString()
+        {
+            return System.Text.Encoding.UTF8.GetString(Encode());
+        }
+        #endregion
+
+
+        #region IDictionary and IList methods
+        public void Add(BEncodedString key, BEncodedValue value)
+        {
+            this.dictionary.Add(key, value);
+        }
+
+        public void Add(KeyValuePair<BEncodedString, BEncodedValue> item)
+        {
+            this.dictionary.Add(item.Key, item.Value);
+        }
+        public void Clear()
+        {
+            this.dictionary.Clear();
+        }
+
+        public bool Contains(KeyValuePair<BEncodedString, BEncodedValue> item)
+        {
+            if (!this.dictionary.ContainsKey(item.Key))
+                return false;
+
+            return this.dictionary[item.Key].Equals(item.Value);
+        }
+
+        public bool ContainsKey(BEncodedString key)
+        {
+            return this.dictionary.ContainsKey(key);
+        }
+
+        public void CopyTo(KeyValuePair<BEncodedString, BEncodedValue>[] array, int arrayIndex)
+        {
+            this.dictionary.CopyTo(array, arrayIndex);
+        }
+
+        public int Count
+        {
+            get { return this.dictionary.Count; }
+        }
+
+        //public int IndexOf(KeyValuePair<BEncodedString, IBEncodedValue> item)
+        //{
+        //    return this.dictionary.IndexOf(item);
+        //}
+
+        //public void Insert(int index, KeyValuePair<BEncodedString, IBEncodedValue> item)
+        //{
+        //    this.dictionary.Insert(index, item);
+        //}
+
+        public bool IsReadOnly
+        {
+            get { return false; }
+        }
+
+        public bool Remove(BEncodedString key)
+        {
+            return this.dictionary.Remove(key);
+        }
+
+        public bool Remove(KeyValuePair<BEncodedString, BEncodedValue> item)
+        {
+            return this.dictionary.Remove(item.Key);
+        }
+
+        //public void RemoveAt(int index)
+        //{
+        //    this.dictionary.RemoveAt(index);
+        //}
+
+        public bool TryGetValue(BEncodedString key, out BEncodedValue value)
+        {
+            return this.dictionary.TryGetValue(key, out value);
+        }
+
+        public BEncodedValue this[BEncodedString key]
+        {
+            get { return this.dictionary[key]; }
+            set { this.dictionary[key] = value; }
+        }
+
+        //public KeyValuePair<BEncodedString, IBEncodedValue> this[int index]
+        //{
+        //    get { return this.dictionary[index]; }
+        //    set { this.dictionary[index] = value; }
+        //}
+
+        public ICollection<BEncodedString> Keys
+        {
+            get { return this.dictionary.Keys; }
+        }
+
+        public ICollection<BEncodedValue> Values
+        {
+            get { return this.dictionary.Values; }
+        }
+
+        public IEnumerator<KeyValuePair<BEncodedString, BEncodedValue>> GetEnumerator()
+        {
+            return this.dictionary.GetEnumerator();
+        }
+
+        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+        {
+            return this.dictionary.GetEnumerator();
+        }
+        #endregion
+    }
+}

src/MonoTorrent/BEncoding/BEncodedList.cs

@@ -0,0 +1,219 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.IO;
+
+namespace MonoTorrent.BEncoding
+{
+    /// <summary>
+    /// Class representing a BEncoded list
+    /// </summary>
+    public class BEncodedList : BEncodedValue, IList<BEncodedValue>
+    {
+        #region Member Variables
+
+        private List<BEncodedValue> list;
+
+        #endregion
+
+
+        #region Constructors
+        /// <summary>
+        /// Create a new BEncoded List with default capacity
+        /// </summary>
+        public BEncodedList()
+            : this(new List<BEncodedValue>())
+        {
+        }
+
+        /// <summary>
+        /// Create a new BEncoded List with the supplied capacity
+        /// </summary>
+        /// <param name="capacity">The initial capacity</param>
+        public BEncodedList(int capacity)
+            : this(new List<BEncodedValue>(capacity))
+        {
+
+        }
+
+        public BEncodedList(IEnumerable<BEncodedValue> list)
+        {
+            if (list == null)
+                throw new ArgumentNullException("list");
+ 
+            this.list = new List<BEncodedValue>(list);
+        }
+
+        private BEncodedList(List<BEncodedValue> value)
+        {
+            this.list = value;
+        }
+
+        #endregion
+
+
+        #region Encode/Decode Methods
+
+
+        /// <summary>
+        /// Encodes the list to a byte[]
+        /// </summary>
+        /// <param name="buffer">The buffer to encode the list to</param>
+        /// <param name="offset">The offset to start writing the data at</param>
+        /// <returns></returns>
+        public override int Encode(byte[] buffer, int offset)
+        {
+            int written = 0;
+            buffer[offset] = (byte)'l';
+            written++;
+            for (int i = 0; i < this.list.Count; i++)
+                written += this.list[i].Encode(buffer, offset + written);
+            buffer[offset + written] = (byte)'e';
+            written++;
+            return written;
+        }
+
+        /// <summary>
+        /// Decodes a BEncodedList from the given StreamReader
+        /// </summary>
+        /// <param name="reader"></param>
+        internal override void DecodeInternal(RawReader reader)
+        {
+            if (reader.ReadByte() != 'l')                            // Remove the leading 'l'
+                throw new BEncodingException("Invalid data found. Aborting");
+
+            while ((reader.PeekByte() != -1) && (reader.PeekByte() != 'e'))
+                list.Add(BEncodedValue.Decode(reader));
+
+            if (reader.ReadByte() != 'e')                            // Remove the trailing 'e'
+                throw new BEncodingException("Invalid data found. Aborting");
+        }
+        #endregion
+
+
+        #region Helper Methods
+        /// <summary>
+        /// Returns the size of the list in bytes
+        /// </summary>
+        /// <returns></returns>
+        public override int LengthInBytes()
+        {
+            int length = 0;
+
+            length += 1;   // Lists start with 'l'
+            for (int i=0; i < this.list.Count; i++)
+                length += this.list[i].LengthInBytes();
+
+            length += 1;   // Lists end with 'e'
+            return length;
+        }
+        #endregion
+
+
+        #region Overridden Methods
+        public override bool Equals(object obj)
+        {
+            BEncodedList other = obj as BEncodedList;
+
+            if (other == null)
+                return false;
+
+            for (int i = 0; i < this.list.Count; i++)
+                if (!this.list[i].Equals(other.list[i]))
+                    return false;
+
+            return true;
+        }
+
+
+        public override int GetHashCode()
+        {
+            int result = 0;
+            for (int i = 0; i < list.Count; i++)
+                result ^= list[i].GetHashCode();
+
+            return result;
+        }
+
+
+        public override string ToString()
+        {
+            return System.Text.Encoding.UTF8.GetString(Encode());
+        }
+        #endregion
+
+
+        #region IList methods
+        public void Add(BEncodedValue item)
+        {
+            this.list.Add(item);
+        }
+
+        public void AddRange (IEnumerable<BEncodedValue> collection)
+        {
+            list.AddRange (collection);
+        }
+
+        public void Clear()
+        {
+            this.list.Clear();
+        }
+
+        public bool Contains(BEncodedValue item)
+        {
+            return this.list.Contains(item);
+        }
+
+        public void CopyTo(BEncodedValue[] array, int arrayIndex)
+        {
+            this.list.CopyTo(array, arrayIndex);
+        }
+
+        public int Count
+        {
+            get { return this.list.Count; }
+        }
+
+        public int IndexOf(BEncodedValue item)
+        {
+            return this.list.IndexOf(item);
+        }
+
+        public void Insert(int index, BEncodedValue item)
+        {
+            this.list.Insert(index, item);
+        }
+
+        public bool IsReadOnly
+        {
+            get { return false; }
+        }
+
+        public bool Remove(BEncodedValue item)
+        {
+            return this.list.Remove(item);
+        }
+
+        public void RemoveAt(int index)
+        {
+            this.list.RemoveAt(index);
+        }
+
+        public BEncodedValue this[int index]
+        {
+            get { return this.list[index]; }
+            set { this.list[index] = value; }
+        }
+
+        public IEnumerator<BEncodedValue> GetEnumerator()
+        {
+            return this.list.GetEnumerator();
+        }
+
+        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+        {
+            return this.GetEnumerator();
+        }
+        #endregion
+    }
+}

src/MonoTorrent/BEncoding/BEncodedNumber.cs

@@ -0,0 +1,209 @@
+using System;
+using System.IO;
+using System.Text;
+using System.Collections.Generic;
+
+namespace MonoTorrent.BEncoding
+{
+    /// <summary>
+    /// Class representing a BEncoded number
+    /// </summary>
+    public class BEncodedNumber : BEncodedValue, IComparable<BEncodedNumber>
+    {
+        #region Member Variables
+        /// <summary>
+        /// The value of the BEncodedNumber
+        /// </summary>
+        public long Number
+        {
+            get { return number; }
+            set { number = value; }
+        }
+        internal long number;
+        #endregion
+
+
+        #region Constructors
+        public BEncodedNumber()
+            : this(0)
+        {
+        }
+
+        /// <summary>
+        /// Create a new BEncoded number with the given value
+        /// </summary>
+        /// <param name="initialValue">The inital value of the BEncodedNumber</param>
+        public BEncodedNumber(long value)
+        {
+            this.number = value;
+        }
+
+        public static implicit operator BEncodedNumber(long value)
+        {
+            return new BEncodedNumber(value);
+        }
+        #endregion
+
+
+        #region Encode/Decode Methods
+
+        /// <summary>
+        /// Encodes this number to the supplied byte[] starting at the supplied offset
+        /// </summary>
+        /// <param name="buffer">The buffer to write the data to</param>
+        /// <param name="offset">The offset to start writing the data at</param>
+        /// <returns></returns>
+        public override int Encode(byte[] buffer, int offset)
+        {
+            long number = this.number;
+
+            int written = offset;
+            buffer[written++] = (byte)'i';
+            
+            if (number < 0)
+            {
+                buffer[written++] = (byte)'-';
+                number = -number;
+            }
+            // Reverse the number '12345' to get '54321'
+            long reversed = 0;
+            for (long i = number; i != 0; i /= 10)
+                reversed = reversed * 10 + i % 10;
+
+            // Write each digit of the reversed number to the array. We write '1'
+            // first, then '2', etc
+            for (long i = reversed; i != 0; i /= 10)
+                buffer[written++] = (byte)(i % 10 + '0');
+
+            if (number == 0)
+                buffer[written++] = (byte)'0';
+
+            // If the original number ends in one or more zeros, they are lost
+            // when we reverse the number. We add them back in here.
+            for (long i = number; i % 10 == 0 && number != 0; i /= 10)
+                buffer[written++] = (byte)'0';
+
+            buffer[written++] = (byte)'e';
+            return written - offset;
+        }
+
+
+        /// <summary>
+        /// Decodes a BEncoded number from the supplied RawReader
+        /// </summary>
+        /// <param name="reader">RawReader containing a BEncoded Number</param>
+        internal override void DecodeInternal(RawReader reader)
+        {
+            int sign = 1;
+            if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            if (reader.ReadByte() != 'i')              // remove the leading 'i'
+                throw new BEncodingException("Invalid data found. Aborting.");
+
+            if (reader.PeekByte() == '-')
+            {
+                sign = -1;
+                reader.ReadByte ();
+            }
+
+            int letter;
+            while (((letter = reader.PeekByte()) != -1) && letter != 'e')
+            {
+                if(letter < '0' || letter > '9')
+                    throw new BEncodingException("Invalid number found.");
+                number = number * 10 + (letter - '0');
+                reader.ReadByte ();
+            }
+            if (reader.ReadByte() != 'e')        //remove the trailing 'e'
+                throw new BEncodingException("Invalid data found. Aborting.");
+
+            number *= sign;
+        }
+        #endregion
+
+
+        #region Helper Methods
+        /// <summary>
+        /// Returns the length of the encoded string in bytes
+        /// </summary>
+        /// <returns></returns>
+        public override int LengthInBytes()
+        {
+            long number = this.number;
+            int count = 2; // account for the 'i' and 'e'
+
+            if (number == 0)
+                return count + 1;
+
+            if (number < 0)
+            {
+                number = -number;
+                count++;
+            }
+            for (long i = number; i != 0; i /= 10)
+                count++;
+
+            return count;
+        }
+
+
+        public int CompareTo(object other)
+        {
+            if (other is BEncodedNumber || other is long || other is int)
+                return CompareTo((BEncodedNumber)other);
+
+            return -1;
+        }
+
+        public int CompareTo(BEncodedNumber other)
+        {
+            if (other == null)
+                throw new ArgumentNullException("other");
+
+            return this.number.CompareTo(other.number);
+        }
+
+
+        public int CompareTo(long other)
+        {
+            return this.number.CompareTo(other);
+        }
+        #endregion
+
+
+        #region Overridden Methods
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="obj"></param>
+        /// <returns></returns>
+        public override bool Equals(object obj)
+        {
+            BEncodedNumber obj2 = obj as BEncodedNumber;
+            if (obj2 == null)
+                return false;
+
+            return (this.number == obj2.number);
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        public override int GetHashCode()
+        {
+            return this.number.GetHashCode();
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <returns></returns>
+        public override string ToString()
+        {
+            return (this.number.ToString());
+        }
+        #endregion
+    }
+}

src/MonoTorrent/BEncoding/BEncodedString.cs

@@ -0,0 +1,220 @@
+using System;
+using System.IO;
+using System.Collections;
+using System.Text;
+using MonoTorrent.Common;
+using MonoTorrent.Messages;
+
+namespace MonoTorrent.BEncoding
+{
+    /// <summary>
+    /// Class representing a BEncoded string
+    /// </summary>
+    public class BEncodedString : BEncodedValue, IComparable<BEncodedString>
+    {
+        #region Member Variables
+
+        /// <summary>
+        /// The value of the BEncodedString
+        /// </summary>
+        public string Text
+        {
+            get { return Encoding.UTF8.GetString(textBytes); }
+            set { textBytes = Encoding.UTF8.GetBytes(value); }
+        }
+
+        /// <summary>
+        /// The underlying byte[] associated with this BEncodedString
+        /// </summary>
+        public byte[] TextBytes
+        {
+            get { return this.textBytes; }
+        }
+        private byte[] textBytes;
+        #endregion
+
+
+        #region Constructors
+        /// <summary>
+        /// Create a new BEncodedString using UTF8 encoding
+        /// </summary>
+        public BEncodedString()
+            : this(new byte[0])
+        {
+        }
+
+        /// <summary>
+        /// Create a new BEncodedString using UTF8 encoding
+        /// </summary>
+        /// <param name="value"></param>
+        public BEncodedString(char[] value)
+            : this(System.Text.Encoding.UTF8.GetBytes(value))
+        {
+        }
+
+        /// <summary>
+        /// Create a new BEncodedString using UTF8 encoding
+        /// </summary>
+        /// <param name="value">Initial value for the string</param>
+        public BEncodedString(string value)
+            : this(System.Text.Encoding.UTF8.GetBytes(value))
+        {
+        }
+
+
+        /// <summary>
+        /// Create a new BEncodedString using UTF8 encoding
+        /// </summary>
+        /// <param name="value"></param>
+        public BEncodedString(byte[] value)
+        {
+            this.textBytes = value;
+        }
+
+
+        public static implicit operator BEncodedString(string value)
+        {
+            return new BEncodedString(value);
+        }
+        public static implicit operator BEncodedString(char[] value)
+        {
+            return new BEncodedString(value);
+        }
+        public static implicit operator BEncodedString(byte[] value)
+        {
+            return new BEncodedString(value);
+        }
+        #endregion
+
+
+        #region Encode/Decode Methods
+
+
+        /// <summary>
+        /// Encodes the BEncodedString to a byte[] using the supplied Encoding
+        /// </summary>
+        /// <param name="buffer">The buffer to encode the string to</param>
+        /// <param name="offset">The offset at which to save the data to</param>
+        /// <param name="e">The encoding to use</param>
+        /// <returns>The number of bytes encoded</returns>
+        public override int Encode(byte[] buffer, int offset)
+        {
+            int written = offset;
+            written += Message.WriteAscii(buffer, written, textBytes.Length.ToString ());
+            written += Message.WriteAscii(buffer, written, ":");
+            written += Message.Write(buffer, written, textBytes);
+            return written - offset;
+        }
+
+
+        /// <summary>
+        /// Decodes a BEncodedString from the supplied StreamReader
+        /// </summary>
+        /// <param name="reader">The StreamReader containing the BEncodedString</param>
+        internal override void DecodeInternal(RawReader reader)
+        {
+            if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            int letterCount;
+            string length = string.Empty;
+
+            while ((reader.PeekByte() != -1) && (reader.PeekByte() != ':'))         // read in how many characters
+                length += (char)reader.ReadByte();                                 // the string is
+
+            if (reader.ReadByte() != ':')                                           // remove the ':'
+                throw new BEncodingException("Invalid data found. Aborting");
+
+            if (!int.TryParse(length, out letterCount))
+                throw new BEncodingException(string.Format("Invalid BEncodedString. Length was '{0}' instead of a number", length));
+
+            this.textBytes = new byte[letterCount];
+            if (reader.Read(textBytes, 0, letterCount) != letterCount)
+                throw new BEncodingException("Couldn't decode string");
+        }
+        #endregion
+
+
+        #region Helper Methods
+        public string Hex
+        {
+            get { return BitConverter.ToString(TextBytes); }
+        }
+
+        public override int LengthInBytes()
+        {
+            // The length is equal to the length-prefix + ':' + length of data
+            int prefix = 1; // Account for ':'
+
+            // Count the number of characters needed for the length prefix
+            for (int i = textBytes.Length; i != 0; i = i/10)
+                prefix += 1;
+
+            if (textBytes.Length == 0)
+                prefix++;
+
+            return prefix + textBytes.Length;
+        }
+
+        public int CompareTo(object other)
+        {
+            return CompareTo(other as BEncodedString);
+        }
+
+
+        public int CompareTo(BEncodedString other)
+        {
+            if (other == null)
+                return 1;
+
+            int difference=0;
+            int length = this.textBytes.Length > other.textBytes.Length ? other.textBytes.Length : this.textBytes.Length;
+
+            for (int i = 0; i < length; i++)
+                if ((difference = this.textBytes[i].CompareTo(other.textBytes[i])) != 0)
+                    return difference;
+
+            if (this.textBytes.Length == other.textBytes.Length)
+                return 0;
+
+            return this.textBytes.Length > other.textBytes.Length ? 1 : -1;
+        }
+
+        #endregion
+
+
+        #region Overridden Methods
+
+        public override bool Equals(object obj)
+        {
+            if (obj == null)
+                return false;
+
+            BEncodedString other;
+            if (obj is string)
+                other = new BEncodedString((string)obj);
+            else if (obj is BEncodedString)
+                other = (BEncodedString)obj;
+            else
+                return false;
+
+            return Toolbox.ByteMatch(this.textBytes, other.textBytes);
+        }
+
+        public override int GetHashCode()
+        {
+            int hash = 0;
+            for (int i = 0; i < this.textBytes.Length; i++)
+                hash += this.textBytes[i];
+
+            return hash;
+        }
+
+        public override string ToString()
+        {
+            return System.Text.Encoding.UTF8.GetString(textBytes);
+        }
+
+        #endregion
+    }
+}

src/MonoTorrent/BEncoding/BEncodingException.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Text;
+using System.Runtime.Serialization;
+
+namespace MonoTorrent.BEncoding
+{
+    [Serializable]
+    public class BEncodingException : Exception
+    {
+        public BEncodingException()
+            : base()
+        {
+        }
+
+        public BEncodingException(string message)
+            : base(message)
+        {
+        }
+
+        public BEncodingException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+        protected BEncodingException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+    }
+}

src/MonoTorrent/BEncoding/IBEncodedValue.cs

@@ -0,0 +1,203 @@
+using System;
+using System.IO;
+using System.Text;
+
+namespace MonoTorrent.BEncoding
+{
+    /// <summary>
+    /// Base interface for all BEncoded values.
+    /// </summary>
+    public abstract class BEncodedValue
+    {
+        internal abstract void DecodeInternal(RawReader reader);
+
+        /// <summary>
+        /// Encodes the BEncodedValue into a byte array
+        /// </summary>
+        /// <returns>Byte array containing the BEncoded Data</returns>
+        public byte[] Encode()
+        {
+            byte[] buffer = new byte[LengthInBytes()];
+            if (Encode(buffer, 0) != buffer.Length)
+                throw new BEncodingException("Error encoding the data");
+
+            return buffer;
+        }
+
+
+        /// <summary>
+        /// Encodes the BEncodedValue into the supplied buffer
+        /// </summary>
+        /// <param name="buffer">The buffer to encode the information to</param>
+        /// <param name="offset">The offset in the buffer to start writing the data</param>
+        /// <returns></returns>
+        public abstract int Encode(byte[] buffer, int offset);
+
+        public static T Clone <T> (T value)
+            where T : BEncodedValue
+        {
+            Check.Value (value);
+            return (T) BEncodedValue.Decode (value.Encode ());
+        }
+
+        /// <summary>
+        /// Interface for all BEncoded values
+        /// </summary>
+        /// <param name="data">The byte array containing the BEncoded data</param>
+        /// <returns></returns>
+        public static BEncodedValue Decode(byte[] data)
+        {
+            if (data == null)
+                throw new ArgumentNullException("data");
+
+            using (RawReader stream = new RawReader(new MemoryStream(data)))
+                return (Decode(stream));
+        }
+
+        internal static BEncodedValue Decode(byte[] buffer, bool strictDecoding)
+        {
+            return Decode(buffer, 0, buffer.Length, strictDecoding);
+        }
+
+        /// <summary>
+        /// Decode BEncoded data in the given byte array
+        /// </summary>
+        /// <param name="buffer">The byte array containing the BEncoded data</param>
+        /// <param name="offset">The offset at which the data starts at</param>
+        /// <param name="length">The number of bytes to be decoded</param>
+        /// <returns>BEncodedValue containing the data that was in the byte[]</returns>
+        public static BEncodedValue Decode(byte[] buffer, int offset, int length)
+        {
+            return Decode(buffer, offset, length, true);
+        }
+
+        public static BEncodedValue Decode(byte[] buffer, int offset, int length, bool strictDecoding)
+        {
+            if (buffer == null)
+                throw new ArgumentNullException("buffer");
+
+            if (offset < 0 || length < 0)
+                throw new IndexOutOfRangeException("Neither offset or length can be less than zero");
+
+            if (offset > buffer.Length - length)
+                throw new ArgumentOutOfRangeException("length");
+
+            using (RawReader reader = new RawReader(new MemoryStream(buffer, offset, length), strictDecoding))
+                return (BEncodedValue.Decode(reader));
+        }
+
+
+        /// <summary>
+        /// Decode BEncoded data in the given stream 
+        /// </summary>
+        /// <param name="stream">The stream containing the BEncoded data</param>
+        /// <returns>BEncodedValue containing the data that was in the stream</returns>
+        public static BEncodedValue Decode(Stream stream)
+        {
+            if (stream == null)
+                throw new ArgumentNullException("stream");
+
+            return Decode(new RawReader(stream));
+        }
+
+
+        /// <summary>
+        /// Decode BEncoded data in the given RawReader
+        /// </summary>
+        /// <param name="reader">The RawReader containing the BEncoded data</param>
+        /// <returns>BEncodedValue containing the data that was in the stream</returns>
+        public static BEncodedValue Decode(RawReader reader)
+        {
+            if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            BEncodedValue data;
+            switch (reader.PeekByte())
+            {
+                case ('i'):                         // Integer
+                    data = new BEncodedNumber();
+                    break;
+
+                case ('d'):                         // Dictionary
+                    data = new BEncodedDictionary();
+                    break;
+
+                case ('l'):                         // List
+                    data = new BEncodedList();
+                    break;
+
+                case ('1'):                         // String
+                case ('2'):
+                case ('3'):
+                case ('4'):
+                case ('5'):
+                case ('6'):
+                case ('7'):
+                case ('8'):
+                case ('9'):
+                case ('0'):
+                    data = new BEncodedString();
+                    break;
+
+                default:
+                    throw new BEncodingException("Could not find what value to decode");
+            }
+
+            data.DecodeInternal(reader);
+            return data;
+        }
+
+
+        /// <summary>
+        /// Interface for all BEncoded values
+        /// </summary>
+        /// <param name="data">The byte array containing the BEncoded data</param>
+        /// <returns></returns>
+        public static T Decode<T>(byte[] data) where T : BEncodedValue
+        {
+            return (T)BEncodedValue.Decode(data);
+        }
+
+
+        /// <summary>
+        /// Decode BEncoded data in the given byte array
+        /// </summary>
+        /// <param name="buffer">The byte array containing the BEncoded data</param>
+        /// <param name="offset">The offset at which the data starts at</param>
+        /// <param name="length">The number of bytes to be decoded</param>
+        /// <returns>BEncodedValue containing the data that was in the byte[]</returns>
+        public static T Decode<T>(byte[] buffer, int offset, int length) where T : BEncodedValue
+        {
+            return BEncodedValue.Decode<T>(buffer, offset, length, true);
+        }
+
+        public static T Decode<T>(byte[] buffer, int offset, int length, bool strictDecoding) where T : BEncodedValue
+        {
+            return (T)BEncodedValue.Decode(buffer, offset, length, strictDecoding);
+        }
+
+
+        /// <summary>
+        /// Decode BEncoded data in the given stream 
+        /// </summary>
+        /// <param name="stream">The stream containing the BEncoded data</param>
+        /// <returns>BEncodedValue containing the data that was in the stream</returns>
+        public static T Decode<T>(Stream stream) where T : BEncodedValue
+        {
+            return (T)BEncodedValue.Decode(stream);
+        }
+
+
+        public static T Decode<T>(RawReader reader) where T : BEncodedValue
+        {
+            return (T)BEncodedValue.Decode(reader);
+        }
+
+
+        /// <summary>
+        /// Returns the size of the byte[] needed to encode this BEncodedValue
+        /// </summary>
+        /// <returns></returns>
+        public abstract int LengthInBytes();
+    }
+}

src/MonoTorrent/BEncoding/RawReader.cs

@@ -0,0 +1,129 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.IO;
+
+namespace MonoTorrent.BEncoding
+{
+    public class RawReader : Stream
+    {
+        bool hasPeek;
+        Stream input;
+        byte[] peeked;
+        bool strictDecoding;
+
+        public bool StrictDecoding
+        {
+            get { return strictDecoding; }
+        }
+
+        public RawReader(Stream input)
+            : this(input, true)
+        {
+
+        }
+
+        public RawReader(Stream input, bool strictDecoding)
+        {
+            this.input = input;
+            this.peeked = new byte[1];
+            this.strictDecoding = strictDecoding;
+        }
+
+        public override bool CanRead
+        {
+            get { return input.CanRead; }
+        }
+
+        public override bool CanSeek
+        {
+            get { return input.CanSeek; }
+        }
+
+        public override bool CanWrite
+        {
+            get { return false; }
+        }
+
+        public override void Flush()
+        {
+            throw new NotSupportedException();
+        }
+
+        public override long Length
+        {
+            get { return input.Length; }
+        }
+
+        public int PeekByte()
+        {
+            if (!hasPeek)
+                hasPeek = Read(peeked, 0, 1) == 1;
+            return hasPeek ? peeked[0] : -1;
+        }
+
+        public override int ReadByte()
+        {
+            if (hasPeek)
+            {
+                hasPeek = false;
+                return peeked[0];
+            }
+            return base.ReadByte();
+        }
+
+        public override long Position
+        {
+            get
+            {
+                if (hasPeek)
+                    return input.Position - 1;
+                return input.Position;
+            }
+            set
+            {
+                if (value != Position)
+                {
+                    hasPeek = false;
+                    input.Position = value;
+                }
+            }
+        }
+
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            int read = 0;
+            if (hasPeek && count > 0)
+            {
+                hasPeek = false;
+                buffer[offset] = peeked[0];
+                offset++;
+                count--;
+                read++;
+            }
+            read += input.Read(buffer, offset, count);
+            return read;
+        }
+
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            long val;
+            if (hasPeek && origin == SeekOrigin.Current)
+                val = input.Seek(offset - 1, origin);
+            else
+                val = input.Seek(offset, origin);
+            hasPeek = false;
+            return val;
+        }
+
+        public override void SetLength(long value)
+        {
+            throw new NotSupportedException();
+        }
+
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            throw new NotSupportedException();
+        }
+    }
+}