private void CheckMetadata(BencodedString announce, BencodedDictionary info)
{
if (announce == null || info == null)
{
throw new TorrentException("Invalid metadata, \'announce\'/\'info\' not of expected type.");
}
}
private void CheckMetadata(BencodedString announce, BencodedDictionary info)
{
if (announce == null || info == null)
{
throw new TorrentException(string.Format("Invalid metadata, 'announce'/'info' not of expected type."));
}
}
private void LoadMetadata()
{
BencodedDictionary metadata = GetMetadata();
var announce = metadata["announce"] as BencodedString;
var info = metadata["info"] as BencodedDictionary;
CheckMetadata(announce, info);
var pieceLength = info["piece length"] as BencodedInteger;
List <byte[]> checksumList = GetRawChecksums(info, pieceLength);
BencodedString name = GetNameFromInfo(info);
List <FileEntry> decodedFiles = DecodeFiles(info, name);
if (metadata.ContainsKey("announce-list"))
{
var announceList = (BencodedList)metadata["announce-list"];
AnnounceList = DecodeAnnounceList(announceList).AsReadOnly();
}
AnnounceURL = announce;
Checksums = checksumList.AsReadOnly();
Files = decodedFiles.AsReadOnly();
PieceLength = pieceLength;
PieceCount = Checksums.Count;
Name = name;
InfoHash = ComputeInfoHash(info);
Announces = CreateAnnouces(AnnounceURL, AnnounceList);
TotalLength = Files.Sum(f => f.Length);
}
/// <summary>
/// Creates a .torrent file with the given data.
/// </summary>
/// <param name="name">The name of the file.</param>
/// <param name="inputFiles">A List'string containing all the files to be added to the .torrent file.</param>
/// <param name="filesDir">The root directory of all the files in the .torrent file.</param>
/// <param name="announce">The announce URL of the tracker, in which the .torrent file will be uploaded to.</param>
/// <param name="announceList">A list of announce URLs.</param>
/// <param name="pieceLength">The number of bytes in each piece.</param>
/// <param name="pieces">A list of strings consisting of the concatenation of all 20-byte SHA1 hash values.</param>
/// <returns>A string representig the content of the .torrent file.</returns>
public static string Create(string name, List <FileEntry> inputFiles, string filesDir, string announce,
List <string> announceList, int pieceLength, List <byte[]> pieces)
{
var clientVersion = Global.Instance.Version;
var res = new BencodedDictionary();
res.Add("announce", new BencodedString(announce));
var alist = new BencodedList();
announceList.ForEach(a => alist.Add(new BencodedList {
new BencodedString(a)
}));
res.Add("announce-list", alist);
res.Add("created by", new BencodedString("rtTorrent/" + clientVersion));
res.Add("creation date", new BencodedInteger(GetUnixTime()));
res.Add("encoding", new BencodedString("UTF-8"));
var info = new BencodedDictionary();
info.Add("piece length", new BencodedInteger(pieceLength));
var piecesString = new StringBuilder();
pieces.ForEach(piece => piece.ForEach(b => piecesString.Append((char)b)));
info.Add("pieces", new BencodedString(piecesString.ToString()));
//"1" - the client MUST publish its presence to get other peers ONLY via the trackers explicitly described in the metainfo file
//"0" - the client may obtain peer from other means, e.g. PEX peer exchange, dht. Here, "private" may be read as "no external peer source".
//info.Add("private", new BencodedInteger(0));
if (inputFiles.Count == 1)
{
info.Add("name", new BencodedString(name));
info.Add("length", new BencodedInteger(inputFiles[0].Length));
//MD5 hash of the file should be added here. The BitTorrent protocol specifies it as NOT needed.
}
else
{
info.Add("name", new BencodedString(filesDir));
var files = new BencodedList();
foreach (var inputFile in inputFiles)
{
var aFile = new BencodedDictionary();
aFile.Add("length", new BencodedInteger(inputFile.Length));
var filePath = new BencodedList();
inputFile.Name.Split(Path.DirectorySeparatorChar).ForEach(
dir => filePath.Add(new BencodedString(dir)));
aFile.Add("path", filePath);
files.Add(aFile);
}
info.Add("files", files);
}
res.Add("info", info);
return(res.ToString());
}
private byte[] ComputeInfoHash(BencodedDictionary info)
{
var hasher = SHA1.Create();
var bencoded = info.ToBencodedString();
var bytes = bencoded.Select(c => (byte)c).ToArray();
var hash = hasher.ComputeHash(bytes);
return(hash);
}
private BencodedString GetNameFromInfo(BencodedDictionary info)
{
var name = info["name"] as BencodedString;
if (name == null)
{
throw new TorrentException("Invalid metadata in file, \'name\' not of expected type.");
}
return(name);
}
private FileEntry CreateTorrentFile(BencodedDictionary file)
{
var filePathList = (file["path"] as BencodedList).Select(s => (string)(s as BencodedString)).ToArray();
var fileLength = file["length"] as BencodedInteger;
CheckFileProperties(filePathList, fileLength);
var filePath = Path.Combine(filePathList);
var torrentFile = new FileEntry(filePath, fileLength);
return(torrentFile);
}
private List <byte[]> GetRawChecksums(BencodedDictionary info, BencodedInteger pieceLength)
{
var rawChecksums = (info["pieces"] as BencodedString).Select(c => (byte)c).ToArray();
if (pieceLength == null || rawChecksums == null || rawChecksums.Length % ChecksumSize != 0)
{
throw new TorrentException(
"Invalid metadata, \'piece length\'/\'pieces\' not of expected type, or invalid length of \'pieces\'.");
}
var slicedChecksums = rawChecksums.Batch(ChecksumSize).Select(e => e.ToArray());
return(slicedChecksums.ToList());
}
private void CheckMetadata(BencodedDictionary metadata)
{
if (metadata == null)
{
throw new TorrentException("Invalid metadata.");
}
if (!metadata.ContainsKey("announce"))
{
throw new TorrentException("Invalid metadata, \'announce\' not found.");
}
if (!metadata.ContainsKey("info"))
{
throw new TorrentException("Invalid metadata, \'info\' not found.");
}
}
private List <FileEntry> DecodeFiles(BencodedDictionary info, BencodedString name)
{
var decodedFiles = new List <FileEntry>();
if (info.ContainsKey("files"))
{
var files = info["files"] as BencodedList;
CheckInfoFiles(files);
foreach (BencodedDictionary file in files)
{
var torrentFile = CreateTorrentFile(file);
decodedFiles.Add(torrentFile);
}
}
else
{
var fileLength = info["length"] as BencodedInteger;
CheckFileLength(fileLength);
decodedFiles.Add(new FileEntry(name, fileLength));
}
return(decodedFiles);
}
private BencodedString GetNameFromInfo(BencodedDictionary info)
{
var name = info["name"] as BencodedString;
if (name == null)
throw new TorrentException(string.Format("Invalid metadata in file, 'name' not of expected type."));
return name;
}
private byte[] HashBencodeDictionary(BencodedDictionary bencodedDictionary)
{
return(new SHA1Managed().ComputeHash(Encoding.GetEncoding(28591).GetBytes(bencodedDictionary.RawValue)));
}
/// <summary>
/// Creates a .torrent file with the given data.
/// </summary>
/// <param name="name">The name of the file.</param>
/// <param name="inputFiles">A List'string containing all the files to be added to the .torrent file.</param>
/// <param name="filesDir">The root directory of all the files in the .torrent file.</param>
/// <param name="announce">The announce URL of the tracker, in which the .torrent file will be uploaded to.</param>
/// <param name="announceList">A list of announce URLs.</param>
/// <param name="pieceLength">The number of bytes in each piece.</param>
/// <param name="pieces">A list of strings consisting of the concatenation of all 20-byte SHA1 hash values.</param>
/// <returns>A string representig the content of the .torrent file.</returns>
public static string Create(string name, List<FileEntry> inputFiles, string filesDir, string announce,
List<string> announceList, int pieceLength, List<byte[]> pieces)
{
Contract.Requires(name != null);
Contract.Requires(inputFiles != null);
Contract.Requires(inputFiles.Count >= 1);
Contract.Requires(announce != null);
Contract.Requires(pieces != null);
var clientVersion = Global.Instance.Version;
var res = new BencodedDictionary();
res.Add("announce", new BencodedString(announce));
var alist = new BencodedList();
announceList.ForEach(a => alist.Add(new BencodedList {new BencodedString(a)}));
res.Add("announce-list", alist);
res.Add("created by", new BencodedString("rtTorrent/" + clientVersion));
res.Add("creation date", new BencodedInteger(GetUnixTime()));
res.Add("encoding", new BencodedString("UTF-8"));
var info = new BencodedDictionary();
info.Add("piece length", new BencodedInteger(pieceLength));
var piecesString = new StringBuilder();
pieces.ForEach(piece => piece.ForEach(b => piecesString.Append((char) b)));
info.Add("pieces", new BencodedString(piecesString.ToString()));
//"1" - the client MUST publish its presence to get other peers ONLY via the trackers explicitly described in the metainfo file
//"0" - the client may obtain peer from other means, e.g. PEX peer exchange, dht. Here, "private" may be read as "no external peer source".
//info.Add("private", new BencodedInteger(0));
if (inputFiles.Count == 1)
{
info.Add("name", new BencodedString(name));
info.Add("length", new BencodedInteger(inputFiles[0].Length));
//MD5 hash of the file should be added here. The BitTorrent protocol specifies it as NOT needed.
}
else
{
info.Add("name", new BencodedString(filesDir));
var files = new BencodedList();
foreach (FileEntry inputFile in inputFiles)
{
var aFile = new BencodedDictionary();
aFile.Add("length", new BencodedInteger(inputFile.Length));
var filePath = new BencodedList();
inputFile.Name.Split(Path.DirectorySeparatorChar).ForEach(
dir => filePath.Add(new BencodedString(dir)));
aFile.Add("path", filePath);
files.Add(aFile);
}
info.Add("files", files);
}
res.Add("info", info);
return res.ToString();
}
private void CheckMetadata(BencodedString announce, BencodedDictionary info)
{
if (announce == null || info == null)
throw new TorrentException(string.Format("Invalid metadata, 'announce'/'info' not of expected type."));
}
private void CheckMetadata(BencodedDictionary metadata)
{
if (metadata == null)
throw new TorrentException(string.Format("Invalid metadata."));
if (!metadata.ContainsKey("announce"))
throw new TorrentException(string.Format("Invalid metadata, 'announce' not found."));
if (!metadata.ContainsKey("info"))
throw new TorrentException(string.Format("Invalid metadata, 'info' not found."));
}
private byte[] ComputeInfoHash(BencodedDictionary info)
{
SHA1 hasher = SHA1.Create();
string bencoded = info.ToBencodedString();
byte[] bytes = bencoded.Select(c => (byte) c).ToArray();
byte[] hash = hasher.ComputeHash(bytes);
return hash;
}
public static IPEndPoint FromBencoded(BencodedDictionary peer)
{
return new IPEndPoint(IPAddress.Parse((BencodedString) peer["ip"]),
(ushort) (BencodedInteger) peer["port"]);
}
private FileEntry CreateTorrentFile(BencodedDictionary file)
{
string[] filePathList = (file["path"] as BencodedList).Select(s => (string) (s as BencodedString)).ToArray();
var fileLength = file["length"] as BencodedInteger;
CheckFileProperties(filePathList, fileLength);
string filePath = Path.Combine(filePathList);
var torrentFile = new FileEntry(filePath, fileLength);
return torrentFile;
}
private List<FileEntry> DecodeFiles(BencodedDictionary info, BencodedString name)
{
var decodedFiles = new List<FileEntry>();
if (info.ContainsKey("files"))
{
var files = info["files"] as BencodedList;
CheckInfoFiles(files);
foreach (BencodedDictionary file in files)
{
FileEntry torrentFile = CreateTorrentFile(file);
decodedFiles.Add(torrentFile);
}
}
else
{
var fileLength = info["length"] as BencodedInteger;
CheckFileLength(fileLength);
decodedFiles.Add(new FileEntry(name, fileLength));
}
return decodedFiles;
}
public static IPEndPoint FromBencoded(BencodedDictionary peer)
{
return(new IPEndPoint(IPAddress.Parse((BencodedString)peer["ip"]),
(ushort)(BencodedInteger)peer["port"]));
}
private List<byte[]> GetRawChecksums(BencodedDictionary info, BencodedInteger pieceLength)
{
byte[] rawChecksums = (info["pieces"] as BencodedString).Select(c=>(byte)c).ToArray();
if (pieceLength == null || rawChecksums == null || rawChecksums.Length%ChecksumSize != 0)
throw new TorrentException(
string.Format(
"Invalid metadata, 'piece length'/'pieces' not of expected type, or invalid length of 'pieces'."));
IEnumerable<byte[]> slicedChecksums = rawChecksums.Batch(ChecksumSize).Select(e => e.ToArray());
return slicedChecksums.ToList();
}
