|
Without more information, it's impossible to help you. You have to know what that file format is (office XML, .ZIP, .RAR, ...) that is holding these files. If it's a custom file format, you're going ot have to find a library or SDK that specifically handles it or write your own. But, in order to do that, you MUST know the exact details of what makes up the archive file format. Without that, you're SOL.
|
|
|
|
|
However one problem that's been annoying me for about a week is when you encryption small files, its hard to decrypt it(I'll post the code soon).
The second problem is when you delete from the datagridview. Here is the use case:
1. User selects file from datagridview.
2. User presses delete to delete the file.
3. Application deletes the file in the secure archive location.(this is the problem)
4. Application deletes the file from the xml.(not a problem)
5. Application keeps running until user exits out.
Here is the full code below. Please note I've deleted from the problem section because I've been trying things and googling alot lately.
Imports System.Xml
Imports System.Object
Imports System.Security
Imports System.Security.Cryptography
Imports System.IO
Imports System.IO.Compression
Imports Ionic.Zip
Public Class EncryptDecryptForm
Public index As Integer
Private Sub EncryptDecryptFormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
File_DataGridView.Rows.Clear()
Environment.Exit(0)
End Sub
Private Sub Encrypt_Browse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Encrypt_Browse.Click
'The code below will open a dialog bos '
Dim find As OpenFileDialog = New OpenFileDialog()
find.Title = "File Vault application" 'Title of file browser'
find.InitialDirectory = "c:\"
find.AddExtension = True
find.Filter = "All files (*.*)|*.*|All files (*.*)|*.*"
find.FilterIndex = 2
find.RestoreDirectory = True
If find.ShowDialog() = Windows.Forms.DialogResult.OK Then
Me.Encrypt_TextBox.Text = find.FileName
End If
End Sub
Private Sub Decrypt_Browse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Decrypt_Browse.Click
'Code below will start the folder browser'
Dim folder As FolderBrowserDialog = New FolderBrowserDialog()
folder.Description = "Select Folder"
folder.RootFolder = Environment.SpecialFolder.MyComputer
If folder.ShowDialog = Windows.Forms.DialogResult.OK Then
Me.Decrypt_TextBox.Text = folder.SelectedPath.ToString
End If
End Sub
Private Sub Encrypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Encrypt.Click
encryption()
End Sub
Private Sub reload()
'This functions reloads the datagrid with the new updated information'
'Replaces the format so the application can read it'
Dim xdoc As XmlDocument = New XmlDocument
xdoc.Load("Resources\FileVault.xml")
Dim name As XmlNodeList = xdoc.GetElementsByTagName("*******")
Dim count As Integer
For count = 0 To (name.Count - 1)
File_DataGridView.Rows.Add(name.Item(count).InnerText.ToString, name.Item(count).InnerText.ToString)
Next count
File_DataGridView.AutoResizeColumns()
File_DataGridView.AutoResizeRows()
End Sub
Private Sub Decrypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Decrypt.Click
decryption()
End Sub
Private Sub EncryptDecryptForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'When the forms load, this sets up the initial columns and what the user can and can not do to them.'
File_DataGridView.Columns.Add("File name", "File name")
File_DataGridView.ColumnHeadersVisible = True
File_DataGridView.ColumnCount = 1
File_DataGridView.AllowUserToResizeColumns = False
File_DataGridView.AllowUserToAddRows = False
File_DataGridView.AllowUserToResizeRows = False
File_DataGridView.AllowUserToOrderColumns = False
File_DataGridView.AllowDrop = False
File_DataGridView.AllowUserToDeleteRows = True
File_DataGridView.AutoGenerateColumns = True
Dim xdoc As XmlDocument = New XmlDocument
xdoc.Load("Resources\FileVault.xml") 'Load Xml file -> declare location here'
Dim name As XmlNodeList = xdoc.GetElementsByTagName("*******") 'Counts these elements'
Dim count As Integer
For count = 0 To (name.Count - 1) 'This for loop fills the data'
File_DataGridView.Rows.Add(name.Item(count).InnerText.ToString, name.Item(count).InnerText.ToString)
Next count
End Sub
'This function creates the encryption key'
Private Function keyencryption(ByVal strPassword As String) As Byte()
'Converting the character to an array and storing the data
Dim chrdata() As Char = strPassword.ToCharArray
'Make is the same length'
Dim Length As Integer = chrdata.GetUpperBound(0)
'starting to hash the data'
Dim bytDataToHash(Length) As Byte
For i As Integer = 0 To chrdata.GetUpperBound(0)
bytDataToHash(i) = CByte(Asc(chrdata(i)))
Next
'Declaring what Hash to use'
Dim SHA512 As New System.Security.Cryptography.SHA512Managed
'Hashing'
Dim Result As Byte() = SHA512.ComputeHash(bytDataToHash)
Dim resIV(31) As Byte
For i As Integer = 0 To 31
resIV(i) = Result(i)
Next
Return resIV
End Function
'Identical function from above except for a few lines
Private Function IVCreation(ByVal strPassword As String) As Byte()
'Converting the character to an array and storing the data
Dim chrdata() As Char = strPassword.ToCharArray
'Make is the same length'
Dim Length As Integer = chrdata.GetUpperBound(0)
'starting to hash the data'
Dim bytDataToHash(Length) As Byte
For i As Integer = 0 To chrdata.GetUpperBound(0)
bytDataToHash(i) = CByte(Asc(chrdata(i)))
Next
'Declaring what Hash to use'
Dim SHA512 As New System.Security.Cryptography.SHA512Managed
'Hashing'
Dim Result As Byte() = SHA512.ComputeHash(bytDataToHash)
Dim resIV(15) As Byte
For i As Integer = 32 To 47
resIV(i - 32) = Result(i)
Next
Return resIV
End Function
Private Function encryption()
'This sub will encrypt the file, xml edits, update the gridview'
'loading the xml document'
Dim xdoc As XmlDocument = New XmlDocument
Dim key As Byte()
Dim IV As Byte()
'The hardcoded password goes here'
'This is a section just in case you want to a password to your encrypted files'
'Right now it uses the hardcoded password'
'If you can expand this if you want'
key = keyencryption(LoginForm.Password_TextBox.Text)
IV = IVCreation(LoginForm.Password_TextBox.Text)
'if there is an error in the application. A error message will be displayed'
Try
'checking to make sure the text box isn't null'
If (Encrypt_TextBox.Text = "") Then
MessageBox.Show("Need to put in a file location")
Else
'Grabing the file name'
Dim locatefilename As String = Me.Encrypt_TextBox.Text
Dim i As Integer = 0
Dim fnPosition As Integer = 0
'locating all the \ in the string'
While locatefilename.IndexOf("\"c, i) <> -1
fnPosition = locatefilename.IndexOf("\"c, i)
i = fnPosition + 1
End While
Dim junk As String
Dim tfile As String
Dim file As String
Dim ext As String
'This should get all the junk that not need for saving files'
'This should capture what you don't need'
junk = locatefilename.Substring(0, fnPosition)
'This should capture the file'
tfile = locatefilename.Substring(fnPosition + 1)
'Zeroing both i and fnPosition'
i = 0
fnPosition = 0
'taking out the extention in the file and saving it to the xml'
While tfile.IndexOf("."c, i) <> -1
fnPosition = tfile.IndexOf("."c, i)
i = fnPosition + 1
End While
'This should get the actually file name'
file = tfile.Substring(0, fnPosition)
'captures the ext (like the txt)'
'Makes the format of the file invisible but only in the xml'
ext = "." & tfile.Substring(fnPosition + 1)
'Checking to make sure there are not duplicate file name'
Dim name As XmlNodeList = xdoc.GetElementsByTagName("*******")
Dim cname As Integer
For cname = 0 To (name.Count - 1)
If (file = name.Item(cname).InnerText) Then
MessageBox.Show("Duplicate file name - either delete the file present in safe or rename file")
Return 1
End If
Next
'This is the file being read in'
Dim fileinput As New System.IO.FileStream(Me.Encrypt_TextBox.Text, IO.FileMode.Open, IO.FileAccess.Read)
'specific file output location here
Dim fileoutput As New System.IO.FileStream("*******", IO.FileMode.Open, IO.FileAccess.Write)
Dim start As Integer = fileoutput.Length
'Declaring variables for encryption'
Dim buffer(4096) As Byte 'Holds the bytes for processing
Dim BytesProcessed As Long = 0 'running count for bytes that are processed'
Dim filelength As Long = fileinput.Length 'Length of file coming in'
Dim bytesinblock As Integer 'current bytes in block'
Dim crypto As CryptoStream
'Declaring crypto service provider'
Dim scRijndael As New System.Security.Cryptography.RijndaelManaged
'setting up progress bars
Encrypt_ProgressBar.Value = 0
Encrypt_ProgressBar.Maximum = 100
crypto = New CryptoStream(fileoutput, scRijndael.CreateEncryptor(key, IV), CryptoStreamMode.Write)
While BytesProcessed < filelength
'reading the file'
bytesinblock = fileinput.Read(buffer, 0, 4096)
'writing the file to cryptoStream'
crypto.Write(buffer, 0, bytesinblock)
'updating bytes processed'
BytesProcessed = BytesProcessed + CLng(bytesinblock)
'equation for updating bytes in block'
Encrypt_ProgressBar.Value = CInt((BytesProcessed / filelength) * 100)
End While
Dim filend As Integer = fileoutput.Length
crypto.Close()
fileinput.Close()
fileoutput.Close()
MessageBox.Show("File is done encrypting")
Encrypt_ProgressBar.Step = 0
Encrypt_ProgressBar.Value = 0
Encrypt_TextBox.Text = ""
'End While
'loading the xml file
xdoc.Load("*******")
'variable for adding a new line'
Dim nline As String = Environment.NewLine
'Creating string for xml file with proper formats'
Dim xmlString As String = nline & " <file>" & nline & " <name>" & file & "</name>" & nline & " <location>" & "Safe\" & file & "</location>" & nline & " <ext>" & ext & "</ext>" & nline & " <beginbyte>" & start & "</beginbyte>" & nline & " <endbytes>" & filend & "</endbytes>" & nline & " </file>" & nline
'the following is used to add the element to the xml'
Dim frag As XmlDocumentFragment = xdoc.CreateDocumentFragment
'Adds the xmlstring to the frag'
frag.InnerXml = xmlString
Dim xroot As XmlNode = xdoc.DocumentElement
'the following statements will add on to the file and save the file'
xroot.AppendChild(frag)
xdoc.Save("*******")
'Clearing the datagrid and reloading the new data, to the eye it you will just blink'
File_DataGridView.Hide()
File_DataGridView.Rows.Clear()
'function reloads the updated xml file'
reload()
File_DataGridView.Show()
End If
Catch ex As Exception
MsgBox(ex.Message)
End Try
Return 1
End Function
Private Function decryption()
'This is function is the same as encryption with just a few changes'
'loading the xml document'
Dim xdoc As XmlDocument = New XmlDocument
Dim key As Byte()
Dim IV As Byte()
'The hardcoded password goes here'
'This is a section just in case you want to a password to your encrypted files'
key = keyencryption(LoginForm.Password_TextBox.Text)
IV = IVCreation(LoginForm.Password_TextBox.Text)
'if there is an error in the application. A error message will be displayed'
Try
'checking to make sure the text box isn't null'
If (Decrypt_TextBox.Text = "") Then
MessageBox.Show("Need to put in the file location or select file in grid for decryption")
Else
'declaring string for file'
Dim file As String
Dim tfile As String
Dim deleteExt As String
Dim output As String
Dim fnPosition As Integer
Dim i As Integer
'locating the selected file in the gridview'
'loading the xml file
xdoc.Load("*******")
'Declare name for xml node'
Dim name As XmlNodeList = xdoc.GetElementsByTagName("*******")
'file location is now saved
file = name.Item(index).InnerText
'Substring of file. This is will be convering the file back to its normal
tfile = file.Substring(5)
'retrieving the extenstion'
Dim extname As XmlNodeList = xdoc.GetElementsByTagName("*******")
Dim replace As String
deleteExt = extname.Item(index).InnerText
'replacing with proper format'
While tfile.IndexOf("."c, i) <> -1
fnPosition = tfile.IndexOf("."c, i)
i = fnPosition + 1
End While
'This should get the actually file name'
replace = (tfile & deleteExt)
'setting the output file with proper format'
output = Decrypt_TextBox.Text & "\" & replace
Dim filebegin As XmlNodeList = xdoc.GetElementsByTagName("*******")
Dim filend As XmlNodeList = xdoc.GetElementsByTagName("*******")
Dim intStart As Integer = filebegin.Item(index).InnerText
Dim intEnd As Integer = filend.Item(index).InnerText
'This is go into the Safe and retrieve file'
Dim fileinput As New System.IO.FileStream("Safe.fva", IO.FileMode.Open, IO.FileAccess.Read)
'specific file output location wiht proper extension'
Dim fileoutput As New System.IO.FileStream(output, IO.FileMode.OpenOrCreate, IO.FileAccess.Write)
'The next line makes sure that the file is empty'
fileoutput.SetLength(0)
'Declaring variables for encryption'
Dim buffer(4096) As Byte 'Holds the bytes for processing
Dim BytesProcessed As Long = 0 'running count for bytes that are processed'
Dim filelength As Long = intEnd - intStart 'Length of file coming in where intEnd will be greater than intStart'
Dim bytesinblock As Integer 'current bytes in block
Dim crypto As CryptoStream
'Declaring crypto service provider'
Dim scRijndael As New System.Security.Cryptography.RijndaelManaged
'setting up progress bars
Encrypt_ProgressBar.Value = 0
Encrypt_ProgressBar.Maximum = 100
crypto = New CryptoStream(fileoutput, scRijndael.CreateDecryptor(key, IV), CryptoStreamMode.Write)
fileinput.Position = intStart
While BytesProcessed < filelength
'reading the file'h
bytesinblock = fileinput.Read(buffer, 0, 4096)
'writing the file to cryptoStream'
crypto.Write(buffer, 0, bytesinblock)
'updating bytes processed'
BytesProcessed = BytesProcessed + CLng(bytesinblock)
'equation for updating bytes in block'
Decrypt_ProgressBar.Value = CInt((BytesProcessed / filelength) * 100)
End While
If (filelength = 0) Then
bytesinblock = fileinput.Read(buffer, 0, 4096)
crypto.Write(buffer, 0, bytesinblock)
End If
crypto.Close()
fileinput.Close()
fileoutput.Close()
MessageBox.Show("File is done decrypting")
Decrypt_ProgressBar.Step = 0
Decrypt_ProgressBar.Value = 0
Decrypt_TextBox.Text = ""
End If
Catch ex As Exception
MsgBox(ex.StackTrace.ToString)
End Try
Return 1
End Function
Public Sub File_DataGridView_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles File_DataGridView.CellClick
index = e.RowIndex
End Sub
Private Sub File_DataGridView_UserDeletingRow(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewRowCancelEventArgs) Handles File_DataGridView.UserDeletingRow
Dim xdoc As XmlDocument = New XmlDocument
xdoc.Load("*******")
Dim filebegin As XmlNodeList = xdoc.GetElementsByTagName("*******")
Dim filend As XmlNodeList = xdoc.GetElementsByTagName("*******")
Dim intStart As Integer = filebegin.Item(index).InnerText
Dim intEnd As Integer = filend.Item(index).InnerText
Dim deletefile As New System.IO.FileStream("*******", FileMode.Open)
Dim deletethis As Integer = CLng(deletefile.Length)
'Deletes the actual file'
Dim location As XmlNodeList = xdoc.GetElementsByTagName("*******")
Dim del_location As String = location.Item(index).InnerText
'Deletes the information in the xml'
Dim name As XmlNodeList = xdoc.GetElementsByTagName("*******")
name.Item(index).RemoveAll()
name.Item(index).ParentNode.RemoveChild(name.Item(index))
xdoc.Save("********")
End Sub
End Class
All help will be greatly appriecated.
|
|
|
|
|
This has got so many problems I don't know where to start.
First, you've got an XML file that holds all the position data in the archive, but you've got nothing persisting this XML data anywhere. Once you're app is closed, it's gone and you have no hope of decrypting the data in the archive, let alone finding it.
You've got no code at all that removes a file from the archive, nor anything that updates pointers to where the remaining files would now be in the modified archive. You've got nothing to add files, nothing to manage the collection of files and the data, no real data structures tracking this stuff, ... basically, this was done entirely wrong. From what I can see in this code, you've got no hope of fixing this because it has to be completely torn down and a new library created that just handles these custom archive files. Forget the form stuff and getting values from TextBox's. The library shouldn't care at all about TextBox's. It should only get it's data from parameters passed into well crafted methods, such as (an overly simplified list!) AddFile(filepath), DeleteFile(filepath), CreateNewArchive(archivePath), ...
|
|
|
|
|
I don't think I need persists when the application isn't going to be web based. I mean it decrypts fine but my problem is deleting the file from the secure file. I understand about the data Structure but this is a application is form based and I have to do it this way. If it was for me, I prolly would use vb to do this.
|
|
|
|
|
No one said anything about this being web-based.
What you have simply isn't going to work - period, end of story. You have nothing managing the format of the file at all, maintaining the indexes where the start of every file is in the archive, which is a non-optional requirement for functionality like this.
|
|
|
|
|
What will be used to manage the xml? An object? make it object orientated.
|
|
|
|
|
That's where your data structures come in. You can create your own class that tracks this information and is serializable.
In my humble opinion, Version 1 of my file format would lay out like this:
preamble bytes (signature)
64-bit integer offset of file table
encrypted file1 bytes
encrypted file2 bytes
encrypted file3 bytes
encrypted file4 bytes
encrypted file5 bytes
.
.
.
file table data
By putting the file table data at the end of the file, you make it easier to add and remove files from the archive as every time you close the archive, you have to write the file table to the end of the file, at a easily obtainable offset. Once that is written, you can update the fixed length 64-bit integer offset with the beginning of the file table.
Like I said, this would be my version 1 layout. Version 2 would probably add a file header to each file with checksum and length data and maybe a second copy of the file table data for backup purposes. You could even write a tool to recover salvagable files from a corrupted archive if you so choose.
Why WOULDN'T I do this? Because if the archive gets damaged, your archive isn't supported by ANY recovery and analysis tools used on other well-known file formats, unless you write these tools yourself.
|
|
|
|
|
So the file data table will be part of the file and not a external source like the xml? So when I need something out the file, I can pull this and check it and than extract the information.
|
|
|
|
|
Yep. Everything in one file and you can easily Seek to anywhere in the file any read/write any number of bytes, so long as you know the file format.
The only problem with a solution like this is when doing file operations in the archive, the easiest implementation maintains the entire file table in memory for the life of the set of operations and gets written out only when the archive is closed. If the machine loses power during this time, you've just corrupted the archive file.
|
|
|
|
|
Private Sub CreateDataTable()
'Creates a better way for securing data'
Dim parent As DataTable = New DataTable("ParentTable")
Dim column As DataColumn = New DataColumn
column.DataType = System.Type.GetType("System.String")
column.ColumnName = "FileName"
column.Unique = True
column.ReadOnly = False
parent.Columns.Add(column)
'Creating a second column'
column = New DataColumn()
column.DataType = System.Type.GetType("System.Byte")
column.ColumnName = "Size of File"
column.Unique = False
column.ReadOnly = True
parent.Columns.Add(column)
'Creating columns for storing data positions'
column = New DataColumn
column.DataType = System.Type.GetType("System.String")
column.ColumnName = "File starting Location"
column.Unique = True
column.ReadOnly = True
parent.Columns.Add(column)
End Sub
|
|
|
|
|
You shouldn't be using a DataTable for this. It's too heavy an object to serialize into your achive file. Create a structure that hold this information, then create a generic collection to hold instances of this structure. For example:
<Serializable> _
Public Structure FileRecord
Public FileName As String
Public PositionOffset As Long
Public EncryptedLength As Long
Public OriginalLength As Long
End Structure
These would be held in a collection declared like this:
Dim fileRecords As New List(Of FileRecord)
.
.
.
Dim newFile As FileRecord
newFile.FileName = "blahh.bla"
newFile.PositionOffset = whateverOffset
newFile.EncryptedLength = whateverByteLength
newFile.OriginalLength = whateverOriginalFileWas
fileRecords.Add( newFile )
|
|
|
|
|
Ok I'll do that.
Which do you think is better? FileStream or BinaryWriter & BinaryReader? When I'm using FileStream the file doesn't go past 194,000KB and it doesn't get any larger.
|
|
|
|
|
Dave,
Its been a while since I've programmed in vb but I'm going to implement a data table and post it on here to see if I'm going in the correct direction.
|
|
|
|
|
If you're talking about keeping users from deleting the archive file, the only way to do that would be to protect the file and it's parent folder with appropriate NTFS permissions.
|
|
|
|
|
I concur with Dave.
I would like to add I don't like encryption or packaging schemes that result in two files; IMO the net result should be a single file, avoiding all possible catastrophes when one file is lost, or the two files don't match together.
What reasons do you have not to use a popular format (ZIP, TAR, ...) and the existing tools or libraries?
|
|
|
|
|
When I asked what was going on, I was about to pull my hair out but after taking a break and coming back I see everything you two are saying. However, this application depends heavily on two forms, its not a web based application, it can't have a database, using .net framework 2.0 so I'm was very  . First Sorry Dave and company for going off. But I really do need some help and would like to build this program as professionally as possible. However, I can't get rid of the forms. Would you people help me out? I see what you mean by pointers but I can't use zip. I distributed it to my customer before and he rejected it because I had to delete the file and he wants it so the OS can't read it. I have the algorithm to do the work but after finding out that he wants 5GB files and very small files. This application will not work for that. I'm going to start this application all over and the file safe.fva is where the file will encrypted and stored. Central location... any help at this time with this will be good.
|
|
|
|
|
OK, this requires that you maintain a filesystem inside a file, which REQUIRES maintaining all this data so that you can perform these file operations and rewrite the archive file as appropriate. You simply have no choice here. What you have isn't going to do the job for you at all. It needs a much more complex solution, which we've already explained.
|
|
|
|
|
Ok... I do need to encrypt this is required. I hate that its required but it needs to be done.
|
|
|
|
|
Why does the doesn't go any further than 194,000 kb?
|
|
|
|
|
I have no idea what you're talking about...
|
|
|
|
|
Hi, I tried do use an typed DataSet (with 2 Tables, 1 Master-detail-Relation),
and wrote:
DataGridView1.DataSource = DataSet1
the Gridview shows the columns well, but null data, null rows.
A Method like DataSet1.Fill I missing, you can me help, how the Data load in the DataSet?
Many thanks, Jan.
|
|
|
|
|
Since your DataSet1 contains 2 Tables, you'll have to set the table you'll want to show.
So use:
DataGridView1.DataSource = DataSet1.Tables("TableName")
|
|
|
|
|
it dosn´t work. may be, the relation between master and detail not is correct?
Im using mysqlconnector 5.1 and made the dataset in vs2008-datenquellen.
the datas are in the dataset - with xml i can all export.
but in the grid nothing to see.....
please help ......
|
|
|
|
|
What do you mean by "It doesn't work"?? What DOES happen? What does the code look like that you're using to set the datasource?
You can use an index number in the DataSet.Tables(index), instead of a string. Have you tried that??
|
|
|
|
|
Fill method belongs to DataAdapter type, not DataSet. Probably your GridView is empty becouse your DataSet is empty. See DataAdapter documentation.
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
