/// <summary>
/// Computes the "info_hash" of the provided torrent (BDictionary).
/// </summary>
/// <param name="torrent">The BDicionary containing the torrent file.</param>
/// <returns>An InfoHash object with the SHA1 hash.</returns>
public static InfoHash ComputeInfoHash(BDictionary torrent)
{
IBValue info = null;
//looks for the "info" dictionary
foreach (KeyValuePair <string, IBValue> item in torrent.Items)
{
if (item.Key == "info" && item.Value is BDictionary)
{
info = item.Value;
break;
}
}
//if found, then computes the SHA1 hash and returns it
if (info != null)
{
//the info_hash is the sha1 hash of the bencoded "info" dictionary, so gets it
string bencoded = info.ToBEncodedString();
List <byte> bytes = new List <byte>(bencoded.Length);
//adds its bytes to a list to be used in the ComputeHash function
foreach (char c in info.ToBEncodedString())
{
bytes.Add((byte)c);
}
SHA1 sha1 = SHA1.Create();
return(InfoHash.FromByteArray(sha1.ComputeHash(bytes.ToArray())));
}
//if the "info" dictionary is not found, then returns an empty InfoHash to avoid exceptions...
return(InfoHash.FromByteArray(new byte[] { }));
}
/// <summary>
/// Private method that parses and returns the dictionary in the current position of the stream.
/// </summary>
/// <param name="br">The BinaryReader with the data to parse.</param>
/// <returns>The dictionary parsed.</returns>
/// <remarks>If the current position does not contain data similar to "dBencoded_stringBencoded_elemente", which is a bencoded dictionary, an exception will be thrown.</remarks>
private static BDictionary ParseDictionary(BinaryReader br)
{
StringBuilder buffer = new StringBuilder(1024);
char c = (char)br.ReadByte();
if (c != 'd')
{
throw new InvalidCharacterException(c, "'d'");
}
BDictionary dictionary = new BDictionary();
do
{
string key = ParseString(br);
IBValue value = Parse(br);
dictionary.Add(key, value);
} while ((char)br.PeekChar() != 'e');
br.ReadByte(); //skips the 'e' char
return(dictionary);
}
/// <summary>
/// Serializes an IBValue to the provided file path.
/// </summary>
/// <param name="value">The IBValue to be serialized.</param>
/// <param name="path">The destination path.</param>
public static void Save(IBValue value, string path)
{
using (FileStream fs = new FileStream(path, FileMode.Create, FileAccess.Write))
{
Save(value, fs);
fs.Close();
}
}
/// <summary>
/// Serializes an IBvalue to the provided stream.
/// </summary>
/// <param name="value">The IBValue to be serialized.</param>
/// <param name="stream">The Stream to receive the serialized data.</param>
public static void Save(IBValue value, Stream stream)
{
BinaryWriter bw = new BinaryWriter(stream);
foreach (char c in value.ToBEncodedString())
{
bw.Write((byte)c);
}
}
/// <summary>
/// Serializes an IBValue to the provided file path.
/// </summary>
/// <param name="value">The IBValue to be serialized.</param>
/// <param name="path">The destination path.</param>
public static void Save(IBValue value, string path)
{
using (FileStream fs = new FileStream(path, FileMode.Create, FileAccess.Write))
{
Save(value, fs);
fs.Close();
}
}
/// <summary>
/// Serializes an IBvalue to the provided stream.
/// </summary>
/// <param name="value">The IBValue to be serialized.</param>
/// <param name="stream">The Stream to receive the serialized data.</param>
public static void Save(IBValue value, Stream stream)
{
BinaryWriter bw = new BinaryWriter(stream);
foreach (char c in value.ToBEncodedString())
{
bw.Write((byte)c);
}
}
/// <summary>
/// Adds an object that implements the IBValue interface to the end of this dictionary.
/// </summary>
/// <param name="key">The key of the element to add.</param>
/// <param name="value">The IBValue element to add.</param>
public void Add(string key, IBValue value)
{
this.items.Add(new KeyValuePair <string, IBValue>(key, value));
}
/// <summary>
/// Adds a new item to this list object.
/// </summary>
/// <param name="value">The IBValue object to add.</param>
public void Add(IBValue value)
{
this.items.Add(value);
}
/// <summary>
/// Adds a new item to this list object.
/// </summary>
/// <param name="value">The IBValue object to add.</param>
public void Add(IBValue value)
{
this.items.Add(value);
}
