internal void OnInput(byte[] ee)
{
var input = Encoding.ASCII.GetString(ee);
//uint32 length
//byte type
//byte[length - 1] data payload
SshDataWorker reader = new SshDataWorker(ee);
SshDataWorker writer = new SshDataWorker();
if (reader.DataAvailable >= 5)
{
var msglength = reader.ReadUInt32();
var msgtype = (RequestPacketType)(int)reader.ReadByte();
uint requestId = 0;
string path = "";
string absolutepath = "";
string handle = Guid.NewGuid().ToString().Replace("-", "");
switch (msgtype)
{
case RequestPacketType.SSH_FXP_INIT:
var sftpclientversion = reader.ReadUInt32();
writer.Write((byte)RequestPacketType.SSH_FXP_VERSION);
var version = Math.Max(3, sftpclientversion);
writer.Write((uint)version); // SFTP protocol version
SendPacket(writer.ToByteArray());
break;
case RequestPacketType.SSH_FXP_REALPATH:
requestId = reader.ReadUInt32();
path = reader.ReadString(Encoding.UTF8);
// List files in root directory for this user
// foreach file create a response message
if (path == ".")
{
path = "/"; // replace with current filepath
}
writer.Write((byte)RequestPacketType.SSH_FXP_NAME);
writer.Write((uint)requestId);
writer.Write((uint)1);
// Dummy file for SSH_FXP_REALPATH request
writer.Write(path, Encoding.UTF8);
writer.Write(@"-rwxr-xr-x 1 mjos staff 348911 Mar 25 14:29 " + path, Encoding.UTF8);
writer.Write((uint)requestId);
writer.Write(uint.MaxValue); // flags
writer.Write((ulong)0); // size
writer.Write(uint.MaxValue); // uid
writer.Write(uint.MaxValue); // gid
writer.Write(uint.MaxValue); // permissions
writer.Write(GetUnixFileTime(DateTime.Now)); //atime
writer.Write(GetUnixFileTime(DateTime.Now)); //mtime
writer.Write((uint)0); // extended_count
//string extended_type blank
//string extended_data blank
SendPacket(writer.ToByteArray());
break;
case RequestPacketType.SSH_FXP_READDIR:
requestId = reader.ReadUInt32();
handle = reader.ReadString(Encoding.UTF8);
if (HandleToPathDictionary.ContainsKey(handle)) // remove after handle is used first time
{
var relativepath = HandleToPathDictionary[handle];
absolutepath = UserRootDirectory + relativepath;
System.IO.DirectoryInfo di = new System.IO.DirectoryInfo(absolutepath);
var allfiles = di.GetFiles();
// returns SSH_FXP_NAME or SSH_FXP_STATUS with SSH_FX_EOF
writer.Write((byte)RequestPacketType.SSH_FXP_NAME);
writer.Write((uint)requestId);
writer.Write((uint)allfiles.Count()); // all files at the same time
foreach (var file in allfiles)
{
writer.Write(GetFileWithAttributes(file));
}
SendPacket(writer.ToByteArray());
HandleToPathDictionary.Remove(handle); // remove will return EOF next time
}
else
{
// return SSH_FXP_STATUS indicating SSH_FX_EOF when all files have been listed
writer.Write((byte)RequestPacketType.SSH_FXP_STATUS);
writer.Write((uint)requestId);
writer.Write((uint)SftpStatusType.SSH_FX_EOF); // status code
//writer.Write("", Encoding.UTF8);
//writer.Write("", Encoding.UTF8);
SendPacket(writer.ToByteArray());
}
break;
case RequestPacketType.SSH_FXP_OPENDIR:
requestId = reader.ReadUInt32();
path = reader.ReadString(Encoding.UTF8);
HandleToPathDictionary.Add(handle, path);
writer.Write((byte)RequestPacketType.SSH_FXP_HANDLE);
writer.Write((uint)requestId);
writer.Write(handle, Encoding.UTF8);
// returns SSH_FXP_HANDLE on success or a SSH_FXP_STATUS message on fail
SendPacket(writer.ToByteArray());
_logger.LogInformation($"sftp command {msgtype} request Id: \"{requestId}\". path: {path} on channel: {channel}");
break;
case RequestPacketType.SSH_FXP_STAT: // follows symbolic links
case RequestPacketType.SSH_FXP_LSTAT: // does not follow symbolic links
requestId = reader.ReadUInt32();
path = reader.ReadString(Encoding.UTF8);
SendAttributes(requestId, path);
break;
case RequestPacketType.SSH_FXP_FSTAT: // SSH_FXP_FSTAT differs from the others in that it returns status information for an open file(identified by the file handle).
requestId = reader.ReadUInt32();
handle = reader.ReadString(Encoding.UTF8);
if (HandleToPathDictionary.ContainsKey(handle))
{
path = HandleToPathDictionary[handle];
SendAttributes(requestId, path);
}
else
{
SendStatus(requestId, SftpStatusType.SSH_FX_NO_SUCH_FILE);
}
break;
case RequestPacketType.SSH_FXP_CLOSE:
requestId = reader.ReadUInt32();
handle = reader.ReadString(Encoding.UTF8);
if (HandleToPathDictionary.ContainsKey(handle))
{
HandleToPathDictionary.Remove(handle);
}
SendStatus(requestId, SftpStatusType.SSH_FX_OK);
break;
case RequestPacketType.SSH_FXP_OPEN:
requestId = reader.ReadUInt32(); //uint32 request-id
path = reader.ReadString(Encoding.UTF8); // //string filename [UTF-8]
HandleToPathDictionary.Add(handle, path);
var desired_access = reader.ReadUInt32();
var flags = reader.ReadUInt32();
//uint32 desired-access
var write = desired_access & (uint)FileSystemOperation.Write;
var read = desired_access & (uint)FileSystemOperation.Read;
var create = desired_access & (uint)FileSystemOperation.Create;
//uint32 flags
//ATTRS attrs
absolutepath = UserRootDirectory + path;
System.IO.FileInfo fi = new System.IO.FileInfo(absolutepath);
if (read > 0 && write == 0 && create == 0)
{
try
{
var fs = fi.OpenRead();
HandleToFileStreamDictionary.Add(handle, fs);
}
catch
{
SendStatus(requestId, SftpStatusType.SSH_FX_PERMISSION_DENIED);
}
}
writer.Write((byte)RequestPacketType.SSH_FXP_HANDLE);
writer.Write((uint)requestId);
writer.Write(handle, Encoding.UTF8);
// returns SSH_FXP_HANDLE on success or a SSH_FXP_STATUS message on fail
SendPacket(writer.ToByteArray());
break;
case RequestPacketType.SSH_FXP_READ:
requestId = reader.ReadUInt32(); //uint32 request-id
handle = reader.ReadString(Encoding.UTF8);
if (HandleToPathDictionary.ContainsKey(handle))
{
var fs = HandleToFileStreamDictionary[handle];
var offset = (long)reader.ReadUInt64();
var length = (int)reader.ReadUInt32();
var buffer = new byte[length];
if (fs.Length - offset < 0) // EOF already reached
{
SendStatus((uint)requestId, SftpStatusType.SSH_FX_EOF);
break;
}
writer.Write((byte)RequestPacketType.SSH_FXP_DATA);
writer.Write((uint)requestId);
if (fs.Length - offset < length)
{
buffer = new byte[fs.Length - offset];
}
fs.Seek(offset, SeekOrigin.Begin);
fs.Read(buffer);
writer.WriteBinary(buffer);
SendPacket(writer.ToByteArray());
}
else
{
// send invalid handle: SSH_FX_INVALID_HANDLE
}
break;
default:
// unsupported command
_logger.LogWarning($"Unsupported sftp command {msgtype.ToString()} input: \"{input}\". on channel: {channel}");
SendStatus(requestId, SftpStatusType.SSH_FX_OP_UNSUPPORTED);
break;
}
}
}
