Changes between Version 34 and Version 35 of HashSourceCodes

Timestamp:

Jul 25, 2011, 2:58:59 PM (13 years ago)

Author:

guest

Comment:

Edited the VB.Net example to use System.Decimal this is a 96bit number and will avoid issues with buffer overflow.

HashSourceCodes

@@ -318 +318 @@
 Imports System.Text
 Imports System.IO
-'Note: you must remove integer overflow checking.
+Imports System.Runtime.InteropServices
 
 Namespace MovieHasher
-        Class Program
-                Private Shared Function ComputeMovieHash(ByVal filename As String) As Byte()
-                        Dim result As Byte()
-                        Using input As Stream = File.OpenRead(filename)
-                                result = ComputeMovieHash(input)
-                        End Using
-                        Return result
-                End Function
-                
-                Private Function ComputeMovieHash(ByVal input As Stream) As Byte()
-                        Dim lhash As System.Int64, streamsize As Long
-                        streamsize = input.Length
-                        lhash = streamsize
-                        
-                        Dim i As Long = 0
-                        Dim buffer As Byte() = New Byte(Marshal.SizeOf(GetType(Long)) - 1) {}
-                        While i < 65536 / Marshal.SizeOf(GetType(Long)) AndAlso (input.Read(buffer, 0, Marshal.SizeOf(GetType(Long))) > 0)
-                                i += 1
-                                
-                                lhash += BitConverter.ToInt64(buffer, 0)
-                        End While
-                        
-                        input.Position = Math.Max(0, streamsize - 65536)
-                        i = 0
-                        While i < 65536 / Marshal.SizeOf(GetType(Long)) AndAlso (input.Read(buffer, 0, Marshal.SizeOf(GetType(Long))) > 0)
-                                i += 1
-                                lhash += BitConverter.ToInt64(buffer, 0)
-                        End While
-                        input.Close()
-                        Dim result As Byte() = BitConverter.GetBytes(lhash)
-                        Array.Reverse(result)
-                        Return result
-                End Function
-                
-                Private Shared Function ToHexadecimal(ByVal bytes As Byte()) As String
-                        Dim hexBuilder As New StringBuilder()
-                        For i As Integer = 0 To bytes.Length - 1
-                                hexBuilder.Append(bytes(i).ToString("x2"))
-                        Next
-                        Return hexBuilder.ToString()
-                End Function
-                
-                Private Shared Sub Main(ByVal args As String())
-                        Dim moviehash As Byte() = ComputeMovieHash("C:\test.avi")
-                        Console.WriteLine("The hash of the movie-file is: {0}", ToHexadecimal(moviehash))
-                End Sub
-        End Class
+    Class Program
+        Private Shared Function ComputeMovieHash(ByVal filename As String) As Byte()
+            Dim result As Byte()
+            Using input As Stream = File.OpenRead(filename)
+                result = ComputeMovieHash(input)
+            End Using
+            Return result
+        End Function
+
+        Private Shared Function ComputeMovieHash(ByVal input As Stream) As Byte()
+            Dim lhash As System.Decimal, streamsize As Long
+            streamsize = input.Length
+            lhash = streamsize
+
+            Dim i As Long = 0
+            Dim buffer As Byte() = New Byte(Marshal.SizeOf(GetType(Long)) - 1) {}
+            While i < 65536 / Marshal.SizeOf(GetType(Long)) AndAlso (input.Read(buffer, 0, Marshal.SizeOf(GetType(Long))) > 0)
+                i += 1
+                lhash += BitConverter.ToInt64(buffer, 0)
+            End While
+
+            input.Position = Math.Max(0, streamsize - 65536)
+            i = 0
+            While i < 65536 / Marshal.SizeOf(GetType(Long)) AndAlso (input.Read(buffer, 0, Marshal.SizeOf(GetType(Long))) > 0)
+                i += 1
+                lhash += BitConverter.ToInt64(buffer, 0)
+            End While
+            input.Close()
+
+            Dim lhashArray() As Integer = Decimal.GetBits(lhash)
+
+            Dim result(7) As Byte
+
+            Array.Copy(BitConverter.GetBytes(lhashArray(0)), 0, result, 0, 4)
+            Array.Copy(BitConverter.GetBytes(lhashArray(1)), 0, result, 4, 4)
+
+            Array.Reverse(result)
+            Return result
+        End Function
+
+        Private Shared Function ToHexadecimal(ByVal bytes As Byte()) As String
+            Dim hexBuilder As New StringBuilder()
+            For i As Integer = 0 To bytes.Length - 1
+                hexBuilder.Append(bytes(i).ToString("x2"))
+            Next
+            Return hexBuilder.ToString()
+        End Function
+
+        Public Sub New(ByVal Path As String)
+            Dim moviehash As Byte() = ComputeMovieHash(Path)
+            Console.WriteLine("The hash of the movie-file is: {0}", ToHexadecimal(moviehash))
+        End Sub
+    End Class
 End Namespace
 }}}