Add skeleton builder for CFB

BurnOutSharp.Builders/CFB.cs

@@ -0,0 +1,138 @@
+using System.IO;
+using System.Text;
+using BurnOutSharp.Models.CFB;
+using BurnOutSharp.Utilities;
+using static BurnOutSharp.Models.CFB.Constants;
+
+namespace BurnOutSharp.Builders
+{
+    public class CFB
+    {
+        #region Byte Data
+
+        /// <summary>
+        /// Parse a byte array into a Compound File Binary
+        /// </summary>
+        /// <param name="data">Byte array to parse</param>
+        /// <param name="offset">Offset into the byte array</param>
+        /// <returns>Filled Compound File Binary on success, null on error</returns>
+        public static Binary ParseBinary(byte[] data, int offset)
+        {
+            // If the data is invalid
+            if (data == null)
+                return null;
+
+            // If the offset is out of bounds
+            if (offset < 0 || offset >= data.Length)
+                return null;
+
+            // Create a memory stream and parse that
+            MemoryStream dataStream = new MemoryStream(data, offset, data.Length - offset);
+            return ParseBinary(dataStream);
+        }
+
+        #endregion
+
+        #region Stream Data
+
+        /// <summary>
+        /// Parse a Stream into a Compound File Binary
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled Compound File Binary on success, null on error</returns>
+        public static Binary ParseBinary(Stream data)
+        {
+            // If the data is invalid
+            if (data == null || data.Length == 0 || !data.CanSeek || !data.CanRead)
+                return null;
+
+            // If the offset is out of bounds
+            if (data.Position < 0 || data.Position >= data.Length)
+                return null;
+
+            // Cache the current offset
+            int initialOffset = (int)data.Position;
+
+            // Create a new binary to fill
+            var binary = new Binary();
+
+            #region Header
+
+            // Try to parse the file header
+            var fileHeader = ParseFileHeader(data);
+            if (fileHeader == null)
+                return null;
+
+            // Set the file header
+            binary.Header = fileHeader;
+
+            #endregion
+
+            // TODO: Implement FAT sector parsing
+            // TODO: Implement Mini FAT sector parsing
+            // TODO: Implement DIFAT sector parsing
+            // TODO: Implement directory sector parsing
+
+            return binary;
+        }
+
+        /// <summary>
+        /// Parse a Stream into a file header
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled file header on success, null on error</returns>
+        private static FileHeader ParseFileHeader(Stream data)
+        {
+            // TODO: Use marshalling here instead of building
+            FileHeader header = new FileHeader();
+
+            header.Signature = data.ReadBytes(8);
+            if (header.Signature != SignatureBytes)
+                return null;
+
+            header.CLSID = data.ReadGuid();
+            header.MinorVersion = data.ReadUInt16();
+            header.MajorVersion = data.ReadUInt16();
+            header.ByteOrder = data.ReadUInt16();
+            if (header.ByteOrder != 0xFFFE)
+                return null;
+
+            header.SectorShift = data.ReadUInt16();
+            if (header.MajorVersion == 3 && header.SectorShift != 0x0009)
+                return null;
+            else if (header.MajorVersion == 4 && header.SectorShift != 0x000C)
+                return null;
+
+            header.MiniSectorShift = data.ReadUInt16();
+            header.Reserved = data.ReadBytes(6);
+            header.NumberOfDirectorySectors = data.ReadUInt32();
+            if (header.MajorVersion == 3 && header.NumberOfDirectorySectors != 0)
+                return null;
+
+            header.NumberOfFATSectors = data.ReadUInt32();
+            header.FirstDirectorySectorLocation = data.ReadUInt32();
+            header.TransactionSignatureNumber = data.ReadUInt32();
+            header.MiniStreamCutoffSize = data.ReadUInt32();
+            if (header.MiniStreamCutoffSize != 0x00001000)
+                return null;
+
+            header.FirstMiniFATSectorLocation = data.ReadUInt32();
+            header.NumberOfMiniFATSectors = data.ReadUInt32();
+            header.FirstDIFATSectorLocation = data.ReadUInt32();
+            header.NumberOfDIFATSectors = data.ReadUInt32();
+            header.DIFAT = new uint[109];
+            for (int i = 0; i < header.DIFAT.Length; i++)
+            {
+                header.DIFAT[i] = data.ReadUInt32();
+            }
+
+            // Skip rest of sector for version 4
+            if (header.MajorVersion == 4)
+                _ = data.ReadBytes(3584);
+
+            return header;
+        }
+
+        #endregion
+    }
+}

BurnOutSharp.Models/CFB/Constants.cs

@@ -2,6 +2,6 @@ namespace BurnOutSharp.Models.CFB
 {
     public static class Constants
     {
-        public static readonly byte[] Signature = new byte[] { 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1 };
+        public static readonly byte[] SignatureBytes = new byte[] { 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1 };
     }
 }

BurnOutSharp.Utilities/Extensions.cs

@@ -271,6 +271,17 @@ namespace BurnOutSharp.Utilities
             return value;
         }
 
+        /// <summary>
+        /// Read a Guid from the stream
+        /// </summary>
+        public static Guid ReadGuid(this byte[] content, ref int offset)
+        {
+            byte[] buffer = new byte[16];
+            Array.Copy(content, offset, buffer, 0, 16);
+            offset += 16;
+            return new Guid(buffer);
+        }
+
         /// <summary>
         /// Read a null-terminated string from the stream
         /// </summary>
@@ -409,6 +420,16 @@ namespace BurnOutSharp.Utilities
             return BitConverter.ToUInt64(buffer, 0);
         }
 
+        /// <summary>
+        /// Read a Guid from the stream
+        /// </summary>
+        public static Guid ReadGuid(this Stream stream)
+        {
+            byte[] buffer = new byte[16];
+            stream.Read(buffer, 0, 16);
+            return new Guid(buffer);
+        }
+
         /// <summary>
         /// Read a null-terminated string from the stream
         /// </summary>