/// <summary>
/// Decodes a BEncodedString from the supplied StreamReader
/// </summary>
/// <param name="reader">The StreamReader containing the BEncodedString</param>
internal override void DecodeInternal(RawReader reader)
{
reader.CannotBeNull();
int letterCount;
string length = string.Empty;
// read in how many characters the string is long
while (reader.PeekByte() != -1 &&
reader.PeekByte() != ':')
{
length += (char)reader.ReadByte();
}
if (reader.ReadByte() != ':')
{
throw new BEncodingException("Invalid data found. Aborting");
}
if (!int.TryParse(length, out letterCount))
{
throw new BEncodingException("Invalid BEncodedString. Could not read the string length.");
}
this.textBytes = new byte[letterCount];
if (reader.Read(this.textBytes, 0, letterCount) != letterCount)
{
throw new BEncodingException("Invalid BEncodedString. The string does not match the specified length.");
}
}
/// <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)
{
reader.CannotBeNull();
BEncodedValue data;
int peekByte = reader.PeekByte();
if (peekByte == 'i')
{
// integer
data = new BEncodedNumber();
data.DecodeInternal(reader);
return(data);
}
else if (peekByte == 'd')
{
// dictionary
data = new BEncodedDictionary();
data.DecodeInternal(reader);
return(data);
}
else if (peekByte == 'l')
{
// list
data = new BEncodedList();
data.DecodeInternal(reader);
return(data);
}
else if (peekByte == '0' ||
peekByte == '1' ||
peekByte == '2' ||
peekByte == '3' ||
peekByte == '4' ||
peekByte == '5' ||
peekByte == '6' ||
peekByte == '7' ||
peekByte == '8' ||
peekByte == '9')
{
// string
data = new BEncodedString();
data.DecodeInternal(reader);
return(data);
}
else
{
throw new BEncodingException("Could not find what value to decode.");
}
}
/// <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>
/// <param name="reader">The reader.</param>
/// <value>
/// The BEncoded dictionary.
/// </value>
public static BEncodedDictionary DecodeTorrent(RawReader reader)
{
reader.CannotBeNull();
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')
{
throw new BEncodingException("Invalid data found. Aborting");
}
return(torrent);
}
/// <summary>
/// Decodes a BEncodedList from the given StreamReader
/// </summary>
/// <param name="reader">The reader.</param>
internal override void DecodeInternal(RawReader reader)
{
reader.CannotBeNull();
if (reader.ReadByte() != 'l')
{
throw new BEncodingException("Invalid data found. Aborting");
}
while (reader.PeekByte() != -1 &&
reader.PeekByte() != 'e')
{
this.list.Add(BEncodedValue.Decode(reader));
}
if (reader.ReadByte() != 'e')
{
throw new BEncodingException("Invalid data found. Aborting");
}
}
/// <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)
{
reader.CannotBeNull();
int sign = 1;
int letter;
if (reader.ReadByte() != 'i')
{
throw new BEncodingException("Invalid data found. Aborting.");
}
if (reader.PeekByte() == '-')
{
sign = -1;
reader.ReadByte();
}
while ((letter = reader.PeekByte()) != -1 &&
letter != 'e')
{
if (letter < '0' ||
letter > '9')
{
throw new BEncodingException("Invalid number found.");
}
this.number = (this.number * 10) + (letter - '0');
reader.ReadByte();
}
if (reader.ReadByte() != 'e')
{
throw new BEncodingException("Invalid data found. Aborting.");
}
this.number *= sign;
}
/// <summary>
/// Decodes the internal.
/// </summary>
/// <param name="reader">The reader.</param>
/// <param name="strictDecoding">if set to <c>true</c> [strict decoding].</param>
/// <exception cref="TorrentClient.BEncoding.BEncodingException">
/// Invalid data found. Aborting
/// or
/// or
/// Invalid data found. Aborting
/// </exception>
private void DecodeInternal(RawReader reader, bool strictDecoding)
{
reader.CannotBeNull();
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($"Illegal BEncodedDictionary. The attributes are not ordered correctly. Old key: {oldkey}, New key: {key}");
}
}
oldkey = key;
value = BEncodedValue.Decode(reader); // the value is a BEncoded value
this.dictionary.Add(key, value);
}
if (reader.ReadByte() != 'e')
{
throw new BEncodingException("Invalid data found. Aborting");
}
}
/// <summary>
/// Decodes the specified reader.
/// </summary>
/// <typeparam name="T">The BEncoded value type.</typeparam>
/// <param name="reader">The reader.</param>
/// <returns>
/// The BEncoded value.
/// </returns>
public static T Decode <T>(RawReader reader) where T : BEncodedValue
{
reader.CannotBeNull();
return((T)BEncodedValue.Decode(reader));
}
/// <summary>
/// Decodes the internal.
/// </summary>
/// <param name="reader">The reader.</param>
internal override void DecodeInternal(RawReader reader)
{
reader.CannotBeNull();
this.DecodeInternal(reader, reader.StrictDecoding);
}