PowerShell .NET and GUI Interfaces

by Lewis · Sat 5th April, 2014

I’ve been grabbing a bit of software from Technet (you know, that thing that Microsoft are shutting down! <_<) and with their download links, they provide SHA1 hashes of the ISOs. I had a quick look around the web for something that allowed you to get SHA1 hashes of files and while I found a few, I didn’t find any that would allow you to provide a hash and compare the resultant hash with the one you’re given by the provider so I decided to write one myself and as with any opportunity, I decided to use PowerShell and .NET with Windows Forms to create a GUI interface as opposed to it all being text based. Sacrilege to those PowerShell purists but it’s a limited feature tool and I wanted to learn something new so here’s the code.

Function Get-FileName($initialDirectory)
{
 [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") |  Out-Null

 $OpenFileDialog = New-Object System.Windows.Forms.OpenFileDialog
 $OpenFileDialog.initialDirectory = $initialDirectory
 $OpenFileDialog.filter = "All files (*.*)| *.*"

 $OpenFileDialog.ShowDialog() | Out-Null
 $OpenFileDialog.filename
} #end function Get-FileName

#We're going to draw a form.
[System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") | Out-Null

#Open a GUI for the user to select the file.
$Filename = Get-FileName -initialDirectory "C:\"

# Check that the path is correct
If (!(Test-Path $Filename)) { Exit }

# Create Input Data (Read the file)
$File = [System.IO.File]::Open($Filename, "open", "read")

# Create a New SHA1 Crypto Provider
$Sha1 = New-Object System.Security.Cryptography.SHA1CryptoServiceProvider

# Output the hash (converted to Hex)
$Hash = [String]::Concat(($Sha1.ComputeHash($File) | % { $_.ToString("x2") }))

#[System.Windows.Forms.MessageBox]::Show("$Hash", "SHA1 Hash", 0)

# Create a GUI Form
$objForm = New-Object System.Windows.Forms.Form
$objForm.Text = "SHA1 Hash Calculator/Comparison Tool"
$objForm.MaximumSize = $objForm.MinimumSize = $objForm.Size = New-Object System.Drawing.Size(400,250)
$objForm.MaximizeBox = $objForm.MinimizeBox = $false
$objForm.StartPosition = "CenterScreen"

# Add a label
$oTitle = New-Object System.Windows.Forms.Label
$oTitle.Location = New-Object System.Drawing.Size(5,5)
$oTitle.Size = New-Object System.Drawing.Size(385,40)
$oTitle.Text = "The calculated hash for your selected file is shown below. You can paste a known hash and compare the two by clicking the compare button."
$objForm.Controls.Add($oTitle)

#File Label
$oFileLabel = New-Object System.Windows.Forms.Label
$oFileLabel.Location = New-Object System.Drawing.Size(5,(53))
$oFileLabel.Size = New-Object System.Drawing.Size(105,20)
$oFileLabel.Text = "File:"
$objForm.Controls.Add($oFileLabel)

# Add a Textbox
$oFileTB = New-Object System.Windows.Forms.TextBox
$oFileTB.Location = New-Object System.Drawing.Size(($oFileLabel.Left + $oFileLabel.Width + 5),($oFileLabel.Top -3))
$oFileTB.Size = New-Object System.Drawing.Size(265,20)
$oFileTB.Text = $Filename.ToString()
$oFileTB.ReadOnly = $true
$objForm.Controls.Add($oFileTB)

# Add a Richtextbox
#$oTitle = New-Object System.Windows.Forms.RichTextBox
#$oTitle.Location = New-Object System.Drawing.Size(0,0)
#$oTitle.Size = New-Object System.Drawing.Size(385,45)

#$oTitle.Rtf = "{\rtf1\ansi\ansicpg1252\deff0\nouicompat\deflang2057{\fonttbl{\f0\fnil\fcharset0 Microsoft Sans Serif;}{\f1\fnil\fcharset0 Calibri;}}
#{\*\generator Riched20 6.3.9600}\viewkind4\uc1
#\pard\sa200\sl276\slmult1\f0\fs16\lang9 The calculated hash for your selected file \b ("+$Filename.Replace("\", "\\")+")\b0  is shown below. You can paste a known hash and compare the two by clicking the compare button.\f1\fs22\par
#}"
#$oTitle.ScrollBars = "None"
#$oTitle.ReadOnly = $True

#$objForm.Controls.Add($oTitle)

# Add a label
$objLabel = New-Object System.Windows.Forms.Label
$objLabel.Location = New-Object System.Drawing.Size(5,(53+50)) # Everything elses location is calculated in reference to this.
$objLabel.Size = New-Object System.Drawing.Size(105,20)
$objLabel.Text = "Calculated SHA1:"
#$objLabel.TextAlign = "MiddleRight"
$objForm.Controls.Add($objLabel)

# Add another label
$objLabel2 = New-Object System.Windows.Forms.Label
$objLabel2.Text = "Comparison SHA1:"
#$objLabel2.TextAlign = "MiddleRight"
$objLabel2.Location = New-Object System.Drawing.Point ($objLabel.Left, ($objLabel.Height + $objLabel.Top + 10))
$objLabel2.Size = New-Object System.Drawing.Size(105,20)
$objForm.Controls.Add($objLabel2)

# Add a Textbox
$objTextBox = New-Object System.Windows.Forms.TextBox
$objTextBox.Location = New-Object System.Drawing.Size(($objLabel.Left + $objLabel.Width + 5),($objLabel.Top -3))
$objTextBox.Size = New-Object System.Drawing.Size(265,20)
$objTextBox.Text = $Hash
$objTextBox.ReadOnly = $true
$objForm.Controls.Add($objTextBox)

# Add comparison box
$objSuppliedVal = New-Object System.Windows.Forms.TextBox
$objSuppliedVal.Location = New-Object System.Drawing.Point ($ObjTextBox.Left, ($objTextBox.Height + $objTextBox.Top + 10))
$objSuppliedVal.Size = New-Object System.Drawing.Size(265,20)
$objForm.Controls.Add($objSuppliedVal)

# Add an Exit button
$ExitButton = New-Object System.Windows.Forms.Button
#$ExitButton.Location = New-Object System.Drawing.Size(300,100)
$ExitButton.Location = New-Object System.Drawing.Point (($ObjTextBox.Right - 75), ($objSuppliedVal.Height + $objSuppliedVal.Top + 10))
$ExitButton.Size = New-Object System.Drawing.Size(75,23)
$ExitButton.Text = "Exit"
#$ExitButton.Add_Click({$objForm.Close()})
$objForm.CancelButton = $ExitButton
$objForm.Controls.Add($ExitButton)

# Add compare button
$CompareButton = New-Object System.Windows.Forms.Button
$CompareButton.Location = New-Object System.Drawing.Point (($ExitButton.Left - $ExitButton.Width - 10), ($objSuppliedVal.Height + $objSuppliedVal.Top + 10))
#$CompareButton.Location = New-Object System.Drawing.Size($ExitButton.Left - $ExitButton.Width - 10,100)
$CompareButton.Size = New-Object System.Drawing.Size(75,23)
$CompareButton.Text = "Compare"
$CompareButton.Add_Click({

    $SuppliedValue = $objSuppliedVal.Text.ToLower()
    $CalculatedValue = $objTextBox.Text.ToLower()

    $MsgBoxButtons = New-Object System.Windows.Forms.MessageBoxButtons
    $MsgBoxIcon = New-Object System.Windows.Forms.MessageBoxIcon

    If ($SuppliedValue -eq $CalculatedValue) {

        $MsgBoxButtons = "OK"
        $MsgBoxIcon = "Information"

        [System.Windows.Forms.MessageBox]::Show("Matched successfully.", "Success", $MsgBoxButtons, $MsgBoxIcon)

    }
    Else {

        $MsgBoxButtons = "OK"
        $MsgBoxIcon = "Warning"

        [System.Windows.Forms.MessageBox]::Show("Not matched.", "Not matched", $MsgBoxButtons, $MsgBoxIcon)

    }

})
$objForm.Controls.Add($CompareButton)

$objForm.Topmost = $true
$objForm.ShowDialog()

# Clear up
$File.Dispose()

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Function Get-FileName($initialDirectory)

{

[System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") | Out-Null

$OpenFileDialog = New-Object System.Windows.Forms.OpenFileDialog

$OpenFileDialog.initialDirectory = $initialDirectory

$OpenFileDialog.filter = "All files (*.*)| *.*"

$OpenFileDialog.ShowDialog() | Out-Null

$OpenFileDialog.filename

} #end function Get-FileName

#We're going to draw a form.

[System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") | Out-Null

#Open a GUI for the user to select the file.

$Filename = Get-FileName -initialDirectory "C:\"

# Check that the path is correct

If (!(Test-Path $Filename)) { Exit }

# Create Input Data (Read the file)

$File = [System.IO.File]::Open($Filename, "open", "read")

# Create a New SHA1 Crypto Provider

$Sha1 = New-Object System.Security.Cryptography.SHA1CryptoServiceProvider

# Output the hash (converted to Hex)

$Hash = [String]::Concat(($Sha1.ComputeHash($File) | % { $_.ToString("x2") }))

#[System.Windows.Forms.MessageBox]::Show("$Hash", "SHA1 Hash", 0)

# Create a GUI Form

$objForm = New-Object System.Windows.Forms.Form

$objForm.Text = "SHA1 Hash Calculator/Comparison Tool"

$objForm.MaximumSize = $objForm.MinimumSize = $objForm.Size = New-Object System.Drawing.Size(400,250)

$objForm.MaximizeBox = $objForm.MinimizeBox = $false

$objForm.StartPosition = "CenterScreen"

# Add a label

$oTitle = New-Object System.Windows.Forms.Label

$oTitle.Location = New-Object System.Drawing.Size(5,5)

$oTitle.Size = New-Object System.Drawing.Size(385,40)

$oTitle.Text = "The calculated hash for your selected file is shown below. You can paste a known hash and compare the two by clicking the compare button."

$objForm.Controls.Add($oTitle)

#File Label

$oFileLabel = New-Object System.Windows.Forms.Label

$oFileLabel.Location = New-Object System.Drawing.Size(5,(53))

$oFileLabel.Size = New-Object System.Drawing.Size(105,20)

$oFileLabel.Text = "File:"

$objForm.Controls.Add($oFileLabel)

# Add a Textbox

$oFileTB = New-Object System.Windows.Forms.TextBox

$oFileTB.Location = New-Object System.Drawing.Size(($oFileLabel.Left + $oFileLabel.Width + 5),($oFileLabel.Top -3))

$oFileTB.Size = New-Object System.Drawing.Size(265,20)

$oFileTB.Text = $Filename.ToString()

$oFileTB.ReadOnly = $true

$objForm.Controls.Add($oFileTB)

# Add a Richtextbox

#$oTitle = New-Object System.Windows.Forms.RichTextBox

#$oTitle.Location = New-Object System.Drawing.Size(0,0)

#$oTitle.Size = New-Object System.Drawing.Size(385,45)

#$oTitle.Rtf = "{\rtf1\ansi\ansicpg1252\deff0\nouicompat\deflang2057{\fonttbl{\f0\fnil\fcharset0 Microsoft Sans Serif;}{\f1\fnil\fcharset0 Calibri;}}

#{\*\generator Riched20 6.3.9600}\viewkind4\uc1

#\pard\sa200\sl276\slmult1\f0\fs16\lang9 The calculated hash for your selected file \b ("+$Filename.Replace("\", "\\")+")\b0 is shown below. You can paste a known hash and compare the two by clicking the compare button.\f1\fs22\par

#}"

#$oTitle.ScrollBars = "None"

#$oTitle.ReadOnly = $True

#$objForm.Controls.Add($oTitle)

# Add a label

$objLabel = New-Object System.Windows.Forms.Label

$objLabel.Location = New-Object System.Drawing.Size(5,(53+50)) # Everything elses location is calculated in reference to this.

$objLabel.Size = New-Object System.Drawing.Size(105,20)

$objLabel.Text = "Calculated SHA1:"

#$objLabel.TextAlign = "MiddleRight"

$objForm.Controls.Add($objLabel)

# Add another label

$objLabel2 = New-Object System.Windows.Forms.Label

$objLabel2.Text = "Comparison SHA1:"

#$objLabel2.TextAlign = "MiddleRight"

$objLabel2.Location = New-Object System.Drawing.Point ($objLabel.Left, ($objLabel.Height + $objLabel.Top + 10))

$objLabel2.Size = New-Object System.Drawing.Size(105,20)

$objForm.Controls.Add($objLabel2)

# Add a Textbox

$objTextBox = New-Object System.Windows.Forms.TextBox

$objTextBox.Location = New-Object System.Drawing.Size(($objLabel.Left + $objLabel.Width + 5),($objLabel.Top -3))

$objTextBox.Size = New-Object System.Drawing.Size(265,20)

$objTextBox.Text = $Hash

$objTextBox.ReadOnly = $true

$objForm.Controls.Add($objTextBox)

# Add comparison box

$objSuppliedVal = New-Object System.Windows.Forms.TextBox

$objSuppliedVal.Location = New-Object System.Drawing.Point ($ObjTextBox.Left, ($objTextBox.Height + $objTextBox.Top + 10))

$objSuppliedVal.Size = New-Object System.Drawing.Size(265,20)

$objForm.Controls.Add($objSuppliedVal)

# Add an Exit button

$ExitButton = New-Object System.Windows.Forms.Button

#$ExitButton.Location = New-Object System.Drawing.Size(300,100)

$ExitButton.Location = New-Object System.Drawing.Point (($ObjTextBox.Right - 75), ($objSuppliedVal.Height + $objSuppliedVal.Top + 10))

$ExitButton.Size = New-Object System.Drawing.Size(75,23)

$ExitButton.Text = "Exit"

#$ExitButton.Add_Click({$objForm.Close()})

$objForm.CancelButton = $ExitButton

$objForm.Controls.Add($ExitButton)

# Add compare button

$CompareButton = New-Object System.Windows.Forms.Button

$CompareButton.Location = New-Object System.Drawing.Point (($ExitButton.Left - $ExitButton.Width - 10), ($objSuppliedVal.Height + $objSuppliedVal.Top + 10))

#$CompareButton.Location = New-Object System.Drawing.Size($ExitButton.Left - $ExitButton.Width - 10,100)

$CompareButton.Size = New-Object System.Drawing.Size(75,23)

$CompareButton.Text = "Compare"

$CompareButton.Add_Click({

$SuppliedValue = $objSuppliedVal.Text.ToLower()

$CalculatedValue = $objTextBox.Text.ToLower()

$MsgBoxButtons = New-Object System.Windows.Forms.MessageBoxButtons

$MsgBoxIcon = New-Object System.Windows.Forms.MessageBoxIcon

If ($SuppliedValue -eq $CalculatedValue) {

$MsgBoxButtons = "OK"

$MsgBoxIcon = "Information"

[System.Windows.Forms.MessageBox]::Show("Matched successfully.", "Success", $MsgBoxButtons, $MsgBoxIcon)

}

Else {

$MsgBoxButtons = "OK"

$MsgBoxIcon = "Warning"

[System.Windows.Forms.MessageBox]::Show("Not matched.", "Not matched", $MsgBoxButtons, $MsgBoxIcon)

}

})

$objForm.Controls.Add($CompareButton)

$objForm.Topmost = $true

$objForm.ShowDialog()

# Clear up

$File.Dispose()

All that lot should give you:
A prompt to select the file you want to calculate the hash of

The hash result

And then, if you supply a hash and click the Compare button, it’ll say either

Now I’m sure there are PowerShell gurus out there that could have all this done in 4 lines of code but it was a learning experience so the code is always likely to be a little more verbose than is absolutely necessary.

Feel free to use the code but plug me as a source if you’re going to use the code on your own blog if you wouldn’t mind.

-Lewis