Patches about VBAMacroReader from poi

main/POIFS/FileSystem/Ole10Native.cs

@@ -28,13 +28,15 @@ namespace NPOI.POIFS.FileSystem
      *
      * @author Rainer Schwarze
      */
+
     public class Ole10Native
     {
         public static String OLE10_NATIVE = "\x0001Ole10Native";
         protected static String ISO1 = "ISO-8859-1";
 
         // (the fields as they appear in the raw record:)
         private int totalSize;             // 4 bytes, total size of record not including this field
+
         private short flags1 = 2;          // 2 bytes, unknown, mostly [02 00]
         private String label;              // ASCIIZ, stored in this field without the terminating zero
         private String fileName;           // ASCIIZ, stored in this field without the terminating zero
@@ -46,8 +48,10 @@ public class Ole10Native
 
         /**
          * the field encoding mode - merely a try-and-error guess ...
-         **/ 
-        private enum EncodingMode {
+         **/
+
+        private enum EncodingMode
+        {
             /**
              * the data is stored in parsed format - including label, command, etc.
              */
@@ -61,8 +65,9 @@ private enum EncodingMode {
              */
             compact
         }
-    
+
         private EncodingMode mode;
+
         /// <summary>
         /// Creates an instance of this class from an embedded OLE Object. The OLE Object is expected
         /// to include a stream &quot;{01}Ole10Native&quot; which Contains the actual
@@ -91,15 +96,17 @@ public static Ole10Native CreateFromEmbeddedOleObject(DirectoryNode directory)
 
             return new Ole10Native(data, 0);
         }
+
         /**
        * Creates an instance and fills the fields based on ... the fields
        */
+
         public Ole10Native(String label, String filename, String command, byte[] data)
         {
-            Label=(label);
-            FileName=(filename);
-            Command=(command);
-            DataBuffer=(data);
+            Label = (label);
+            FileName = (filename);
+            Command = (command);
+            DataBuffer = (data);
             mode = EncodingMode.parsed;
         }
 
@@ -110,6 +117,7 @@ public Ole10Native(String label, String filename, String command, byte[] data)
          * @param offset The start offset of the record in the buffer
          * @throws Ole10NativeException on invalid or unexcepted data format
          */
+
         public Ole10Native(byte[] data, int offset)
         {
             int ofs = offset;        // current offset, Initialized to start
@@ -172,25 +180,31 @@ public Ole10Native(byte[] data, int offset)
                     }
 
                     break;
+
                 case EncodingMode.compact:
                     flags1 = LittleEndian.GetShort(data, ofs);
                     ofs += LittleEndianConsts.SHORT_SIZE;
                     dataSize = totalSize - LittleEndianConsts.SHORT_SIZE;
                     break;
+
                 case EncodingMode.unparsed:
                     dataSize = totalSize;
                     break;
+            }
 
+            if ((long)dataSize + (long)ofs > (long)data.Length)
+            { //cast to avoid overflow
+                throw new Ole10NativeException("Invalid Ole10Native: declared data length > available data");
             }
             dataBuffer = new byte[dataSize];
             Array.Copy(data, ofs, dataBuffer, 0, dataSize);
             ofs += dataSize;
-
         }
 
         /*
          * Helper - determine length of zero terminated string (ASCIIZ).
          */
+
         private static int GetStringLength(byte[] data, int ofs)
         {
             int len = 0;
@@ -208,6 +222,7 @@ private static int GetStringLength(byte[] data, int ofs)
          *
          * @return the totalSize
          */
+
         public int TotalSize
         {
             get
@@ -221,6 +236,7 @@ public int TotalSize
          *
          * @return the flags1
          */
+
         public short Flags1
         {
             get
@@ -236,6 +252,7 @@ public short Flags1
          *
          * @return the label
          */
+
         public String Label
         {
             get
@@ -254,6 +271,7 @@ public String Label
          *
          * @return the fileName
          */
+
         public String FileName
         {
             get
@@ -271,6 +289,7 @@ public String FileName
          *
          * @return the flags2
          */
+
         public short Flags2
         {
             get
@@ -288,6 +307,7 @@ public short Flags2
          *
          * @return the unknown1
          */
+
         public short Unknown1
         {
             get
@@ -306,6 +326,7 @@ public short Unknown1
          *
          * @return the command
          */
+
         public String Command
         {
             get
@@ -322,10 +343,10 @@ public String Command
          *
          * @return the dataSize
          */
+
         public int DataSize
         {
-            get{return dataBuffer.Length;}
-
+            get { return dataBuffer.Length; }
         }
 
         /**
@@ -336,17 +357,19 @@ public int DataSize
          *
          * @return the dataBuffer
          */
+
         public byte[] DataBuffer
         {
             get { return dataBuffer; }
-            set { dataBuffer =(byte[])value.Clone(); }
+            set { dataBuffer = (byte[])value.Clone(); }
         }
 
         /**
          * Returns the flags3 - currently unknown.
          *
          * @return the flags3
          */
+
         public short Flags3
         {
             get
@@ -365,12 +388,13 @@ public short Flags3
    * around, but non atom classes will just request the bytes from their
    * children, then chuck on their header and return)
    */
+
         public void WriteOut(Stream out1)
         {
             byte[] intbuf = new byte[LittleEndianConsts.INT_SIZE];
             byte[] shortbuf = new byte[LittleEndianConsts.SHORT_SIZE];
             byte[] zerobuf = { 0, 0, 0, 0 };
-            
+
             LittleEndianOutputStream leosOut = new LittleEndianOutputStream(out1);
 
             switch (mode)
@@ -405,20 +429,13 @@ public void WriteOut(Stream out1)
                     leosOut.WriteShort(Flags1);
                     out1.Write(DataBuffer, 0, DataBuffer.Length);
                     break;
+
                 default:
                 case EncodingMode.unparsed:
                     leosOut.WriteInt(DataSize);
                     out1.Write(DataBuffer, 0, DataBuffer.Length);
                     break;
             }
-
         }
-
     }
-
 }
-
-
-
-
-