Fix SftpFileAttributes file type detection (#1688)

* Fix SftpFileAttributes file type detection

To get the file type, S_IFMT should be used as the mask. Instead it was using each file
type as the mask. It meant that e.g. a symbolic link would also show as a regular file
and a character device.

Also allow setting and retrieving the setuid/setgid/sticky bits

* fix build

Author: Rob-Hague

src/Renci.SshNet/Sftp/Requests/SftpMkDirRequest.cs

@@ -8,7 +8,6 @@ namespace Renci.SshNet.Sftp.Requests
     internal sealed class SftpMkDirRequest : SftpRequest
     {
         private byte[] _path;
-        private byte[] _attributesBytes;
 
         public override SftpMessageTypes SftpMessageType
         {
@@ -23,18 +22,6 @@ public string Path
 
         public Encoding Encoding { get; private set; }
 
-        private SftpFileAttributes Attributes { get; set; }
-
-        private byte[] AttributesBytes
-        {
-            get
-            {
-                _attributesBytes ??= Attributes.GetBytes();
-
-                return _attributesBytes;
-            }
-        }
-
         /// <summary>
         /// Gets the size of the message in bytes.
         /// </summary>
@@ -48,36 +35,30 @@ protected override int BufferCapacity
                 var capacity = base.BufferCapacity;
                 capacity += 4; // Path length
                 capacity += _path.Length; // Path
-                capacity += AttributesBytes.Length; // Attributes
+                capacity += 4; // Attributes
                 return capacity;
             }
         }
 
         public SftpMkDirRequest(uint protocolVersion, uint requestId, string path, Encoding encoding, Action<SftpStatusResponse> statusAction)
-            : this(protocolVersion, requestId, path, encoding, SftpFileAttributes.Empty, statusAction)
-        {
-        }
-
-        private SftpMkDirRequest(uint protocolVersion, uint requestId, string path, Encoding encoding, SftpFileAttributes attributes, Action<SftpStatusResponse> statusAction)
             : base(protocolVersion, requestId, statusAction)
         {
             Encoding = encoding;
             Path = path;
-            Attributes = attributes;
         }
 
         protected override void LoadData()
         {
             base.LoadData();
             _path = ReadBinary();
-            Attributes = ReadAttributes();
+            _ = ReadAttributes();
         }
 
         protected override void SaveData()
         {
             base.SaveData();
             WriteBinaryString(_path);
-            Write(AttributesBytes);
+            Write(0u); // empty attributes
         }
     }
 }

src/Renci.SshNet/Sftp/Requests/SftpOpenRequest.cs

@@ -9,7 +9,6 @@ internal sealed class SftpOpenRequest : SftpRequest
     {
         private readonly Action<SftpHandleResponse> _handleAction;
         private byte[] _fileName;
-        private byte[] _attributes;
 
         public override SftpMessageTypes SftpMessageType
         {
@@ -24,12 +23,6 @@ public string Filename
 
         public Flags Flags { get; }
 
-        public SftpFileAttributes Attributes
-        {
-            get { return SftpFileAttributes.FromBytes(_attributes); }
-            private set { _attributes = value.GetBytes(); }
-        }
-
         public Encoding Encoding { get; }
 
         /// <summary>
@@ -46,23 +39,17 @@ protected override int BufferCapacity
                 capacity += 4; // FileName length
                 capacity += _fileName.Length; // FileName
                 capacity += 4; // Flags
-                capacity += _attributes.Length; // Attributes
+                capacity += 4; // Attributes
                 return capacity;
             }
         }
 
         public SftpOpenRequest(uint protocolVersion, uint requestId, string fileName, Encoding encoding, Flags flags, Action<SftpHandleResponse> handleAction, Action<SftpStatusResponse> statusAction)
-            : this(protocolVersion, requestId, fileName, encoding, flags, SftpFileAttributes.Empty, handleAction, statusAction)
-        {
-        }
-
-        private SftpOpenRequest(uint protocolVersion, uint requestId, string fileName, Encoding encoding, Flags flags, SftpFileAttributes attributes, Action<SftpHandleResponse> handleAction, Action<SftpStatusResponse> statusAction)
             : base(protocolVersion, requestId, statusAction)
         {
             Encoding = encoding;
             Filename = fileName;
             Flags = flags;
-            Attributes = attributes;
 
             _handleAction = handleAction;
         }
@@ -79,7 +66,7 @@ protected override void SaveData()
 
             WriteBinaryString(_fileName);
             Write((uint)Flags);
-            Write(_attributes);
+            Write(0u); // empty attributes
         }
 
         public override void Complete(SftpResponse response)

src/Renci.SshNet/Sftp/Responses/SftpVersionResponse.cs

@@ -11,14 +11,14 @@ public override SftpMessageTypes SftpMessageType
 
         public uint Version { get; set; }
 
-        public IDictionary<string, string> Extentions { get; set; }
+        public IDictionary<string, string> Extensions { get; set; }
 
         protected override void LoadData()
         {
             base.LoadData();
 
             Version = ReadUInt32();
-            Extentions = ReadExtensionPair();
+            Extensions = ReadExtensionPair();
         }
 
         protected override void SaveData()
@@ -27,9 +27,9 @@ protected override void SaveData()
 
             Write(Version);
 
-            if (Extentions != null)
+            if (Extensions != null)
             {
-                Write(Extentions);
+                Write(Extensions);
             }
         }
     }