Mysterius一字节溢出 [英] Mysterius one byte overflow

问题描述

嘿..！

再次让我陷入了困境……

我正在制作一个程序，可以读取文件(exe和dll)并进行比较一个字节接一个字节，然后保存差异....
现在，我遇到了问题...当我读取文件时，它崩溃了.当二进制读取器到达位置3(RAW偏移量0x03)时，它崩溃并显示以下语句:算术运算导致溢出.我尝试了不同的文件，它始终位于位置3.

这是我的代码:

Hey..!

Once again i got myself into a pickle...

I am making a program that reads files (exe and dll) and compares them byte for byte and then save the diffrences....
Now, i get a problem... when i read the file it crashes. when the binary reader reaches position 3 (RAW offset 0x03) it crashes with the sentence: Arithmic operation resulted in an overflow. I tried different files and its always at position 3.

Here is my code:

Dim f1 As String
        Dim f1l As Long
        Dim f1h As String
        Dim f1c As String
        Dim f1o As Long 'fil1 start offset

        Dim f2 As String
        Dim f2l As Long
        Dim f2h As String
        Dim f2c As String
        Dim f2o As Long

        statuslbl.Text = "Gathering Information on files"

        f1 = TextBox1.Text
        f1c = My.Computer.FileSystem.ReadAllText(f1)
        f2 = TextBox2.Text
        f2c = My.Computer.FileSystem.ReadAllText(f2)


        opb.Value = 0
        rpb.Value = 0


        Application.DoEvents()


        If FileLen(f1) > FileLen(f2) Then rpb.Maximum = FileLen(f1)
        If FileLen(f1) < FileLen(f2) Then rpb.Maximum = FileLen(f2)

        f1l = FileLen(f1)
        f1h = getMd5Hash(f1c)
        f2l = FileLen(f2)
        f2h = getMd5Hash(f2c)


        his.AppendText(Environment.NewLine & "File1 length: " & f1l)
        his.AppendText(Environment.NewLine & "File2 length: " & f2l)
        his.AppendText(Environment.NewLine)
        his.AppendText(Environment.NewLine & "File1 hash: " & f1h)
        his.AppendText(Environment.NewLine & "File2 hash: " & f2h)


        Application.DoEvents()


        statuslbl.Text = "Comparing Bytes"
        Dim f1r As New IO.BinaryReader(File.Open(f1, FileMode.Open))
        Dim f2r As New IO.BinaryReader(File.Open(f2, FileMode.Open))
        f1o = f1r.BaseStream.Position
        f2o = f2r.BaseStream.Position

        his.AppendText(Environment.NewLine)
        his.AppendText(Environment.NewLine & "File1 start RAWoffset: " & f1o)
        his.AppendText(Environment.NewLine & "File2 start RAWoffset: " & f2o)

        Dim finished As Boolean = False
        Dim table() As diffrence
        Dim counter As Integer = 0

        While finished = False
            Dim ob As Byte
            Dim nb As Byte

            If f1r.BaseStream.Position.Equals(f1l) = False Then
                ob = f1r.Read
            Else
                ob = &HFF
            End If
            If f2r.BaseStream.Position.Equals(f2l) = False Then
                nb = f2r.Read
            Else
                nb = &HFF
            End If


            If ob.Equals(nb) = False Then
                Dim dif As New diffrence
                dif.ByteOffset = f2r.BaseStream.Position
                dif.NewByte = nb
                dif.OldByte = ob

                table(counter) = dif
                counter = counter + 1
            End If

            If f1r.BaseStream.Position.Equals(f1l) = True Then
                If f2r.BaseStream.Position.Equals(f2l) = True Then
                    finished = True
                End If
            End If

        End While

        statuslbl.Text = "Compared done"

        dgv.DataSource = table

    End Sub

diffrence()类是我自己编写的，下面是该代码:

The diffrence() class is one i wrote myself, here is the code for that:

Public Class diffrence
    Dim boffset As Long
    Dim oldb As Byte
    Dim newb As Byte

    Public Property ByteOffset()
        Get
            Return boffset
        End Get
        Set(ByVal value)
            boffset = value
        End Set
    End Property

    Public Property NewByte()
        Get
            Return newb
        End Get
        Set(ByVal value)
            newb = value
        End Set
    End Property

    Public Property OldByte()
        Get
            Return oldb
        End Get
        Set(ByVal value)
            oldb = value
        End Set
    End Property
End Class

我真的希望有人可以帮我解决这个问题....！

问候
马丁

---

马丁·约根森

I really hope someone can help me with this....!

Regards
Martin

---

Martin Jørgensen

推荐答案

我不知道您是否尝试这样做，但是我使用它比较两个文件是否相等

I dont know if this what you try to do but i use it to compare two files for equality

 'compare
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        If TextBox1.TextLength = 0 Or TextBox3.TextLength = 0 Then
            MsgBox("You must select two files to compare", MsgBoxStyle.Exclamation, "File Error")
            Exit Sub
        End If
        
        Dim hash As System.Security.Cryptography.HashAlgorithm
        hash = System.Security.Cryptography.HashAlgorithm.Create

        Dim fs1 As New FileStream(TextBox1.Text, FileMode.Open)
        Dim hashF1() As Byte = hash.ComputeHash(fs1)
        fs1.Close()

        Dim fs2 As New FileStream(TextBox3.Text, FileMode.Open)
        Dim hashF2() As Byte = hash.ComputeHash(fs2)
        fs2.Close()

        If BitConverter.ToString(hashF1) = BitConverter.ToString(hashF2) Then
            Label1.Text = "File is the same"
            Label1.BackColor = Color.LimeGreen
        Else
            Label1.Text = "File is not the same"
            Label1.BackColor = Color.Red
        End If

        
    End Sub

kaymaf

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